研究者詳細 - 則永　行庸

Resolving passive heat transfer and phase-change heat in cryogenic CO2 deposition (Desublimation) from CO2/N2 mixtures 査読有り Open Access

Xiao, SW; Machida, H; Norinaga, K

AICHE JOURNAL 2026年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Aiche Journal

In cryogenic CO<inf>2</inf> desublimation systems where phase change dominates both heat transfer and separation, conventional lumped thermal-resistance treatments embed interfacial latent heat into an overall heat-transfer coefficient, obscuring how phase-change heat is partitioned between the gas phase and the coolant and limiting diagnostic insight into energy efficiency. In this study, CO<inf>2</inf> desublimation experiments were conducted using CO<inf>2</inf>/N<inf>2</inf> mixtures, and a coupled heat- and mass-transfer model incorporating phase-change effects was developed. By explicitly treating the latent heat released at the gas–solid interface as an internal heat source within a thermal-resistance network, a heat-splitting performance index (HSPI) was introduced to quantify the fraction of latent heat coupled to the coolant side. The results show that both CO<inf>2</inf> recovery and coolant-side latent-heat utilization increase monotonically with the inlet CO<inf>2</inf> mole fraction, highlighting feed-gas composition as a key determinant of separation performance and energy efficiency in cryogenic CO<inf>2</inf> capture.

DOI： 10.1002/aic.70468

Numerical analysis of gas-liquid countercurrent flow in a pressure-swing CO2 desorber operated at reduced pressure 査読有り

Saito, Y; Tashiro, G; Chairunnisa; Miyazaki, T; Uehara, Y; Machida, H; Norinaga, K

CHEMICAL ENGINEERING SCIENCE 325 巻 2026年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

Understanding fluid behavior in packed columns is essential for improving the efficiency of CO<inf>2</inf> capture processes. This study presents three-dimensional numerical simulations of gas–liquid countercurrent flow in a random packed bed of a desorber operated under reduced pressure in a pressure-swing mode. The applicability of existing correlations for liquid holdup, originally developed for absorbers, was evaluated under desorber conditions. A realistic random packing structure was numerically reconstructed, and variations in liquid viscosity and surface tension along the bed height were incorporated to represent CO<inf>2</inf> release during desorption. The results showed that liquid holdup increased with the progress of CO<inf>2</inf> desorption, while both liquid flux and the number of liquid nozzles had a strong influence on the gas–liquid interfacial area and liquid distribution. Numerical predictions of liquid holdup showed reasonable consistency with existing correlations, providing a comparative basis for discussing liquid distribution under desorber conditions. Overall, this study provides a quantitative framework for analyzing liquid flow behavior with property variations in random packed beds, contributing to the improved design and operation of CO<inf>2</inf> capture units.

DOI： 10.1016/j.ces.2026.123395

Engineering Bilayer Tandem Catalysts on Si-Based Photocathodes for High-performance CO2 Reduction to Produce Methane 査読有り Open Access

Wu, H; Si, SH; Wang, HT; Wang, CL; Dai, RC; Li, JN; Fukaya, S; Pan, ZH; Xiong, YJ; Usami, N; Norinaga, K; Kurokawa, Y; Sirisomboonchai, S; Liu, D; Wang, Q

ADVANCED MATERIALS 38 巻 ( 15 ) 頁： e18249 2026年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Advanced Materials

Solar-powered CO<inf>2</inf> reduction through photoelectrochemical (PEC) approaches to produce hydrocarbon fuels, such as methane (CH<inf>4</inf>), is one of the most promising paths for supplying sustainable fuels. However, the limited light absorption capability and sluggish kinetics restrict the photocatalytic rate and selectivity for hydrocarbon production. Here, we introduce tandem catalysts on photocathodes designed to enhance controlled sequential reactions involving intermediates and thus the selectivity of CO<inf>2</inf> reduction. Specifically, when mounted on Cu/Ag-Cu bilayer catalysts, the p-type Si photocathode with a pyramid-structured surface dramatically improves CO<inf>2</inf>-to-CH<inf>4</inf> conversion, achieving a selectivity of 60.2 ± 3.4% and a working current density of −32.9 ± 1.9 mA cm−2 at −1.1 V vs. RHE. As identified by operando Raman and synchrotron-radiation Fourier transform infrared spectroscopy and Density Functional Theory, the bottom layer of the Cu/Ag-Cu catalysts comprises Ag and Cu nanoparticles, which catalyse the initial reduction of CO<inf>2</inf> to form *CO and the creation of *H species dissociated from H<inf>2</inf>O, respectively. The top Cu layer subsequently enables the protonation of *CO to *CHO, ultimately yielding CH<inf>4</inf>. This design of tandem catalysts, coupled with a thorough investigation of the reaction mechanisms, offers a powerful approach toward high-performance and selective pathways for solar-powered CO<inf>2</inf> reduction to targeted products.

DOI： 10.1002/adma.202518249

PubMed

Mechanistic and Stability Study of the Integrated CO2 Capture-Electroreduction Process in Ethanolamine Solution over Ni/NC Atomic Catalysts 査読有り Open Access

Dai, RC; Zhang, LJ; Yuan, XR; He, YT; Lin, YX; Wu, H; Wu, WJ; Machida, H; Norinaga, K

CARBON CAPTURE SCIENCE & TECHNOLOGY 18 巻 2026年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Capture Science and Technology

In recent years, the integrated systems for the cost-effective conversion of CO<inf>2</inf> into high-value products have emerged as a major research focus in advancing sustainable green chemistry. The integrated process not only addresses the high energy consumption during desorption but also simplifies the process and reduces costs. However, further improving CO<inf>2</inf> conversion efficiency and achieving system stability remain significant challenges. Here, we report an integrated CO<inf>2</inf> capture and electroreduction process (ICCE) using atomically dispersed Nickel catalysts (Ni/NC) for the direct electroreduction of CO<inf>2</inf> absorbed in 30 wt.% ethanolamine (MEA, MAE, EAE, DMEA) solutions to CO, achieving a high Faradaic efficiency of up to 91%. In addition, the authors compared the effects of different reaction temperatures and different partial pressures of CO<inf>2</inf> in the gas phase on the prolonged electroreduction reaction, and suggested that the integrated system maintaining a gas-liquid equilibrium, can be guaranteed to continuously electrolyze to produce CO at a high Faraday efficiency. Through multiple characterizations, like NMR spectroscopy and In-situ Raman spectroscopy, revealed that CO is primarily derived from interfacially regenerated free CO<inf>2</inf>, while carbamate species are not directly reduced but instead adsorb on the Ni/NC catalyst surface as inhibitory intermediates.

DOI： 10.1016/j.ccst.2026.100583

Numerical Analysis of CO2 Deposition in a Sublimation Tank and Evaluation of Property Parameter Effects 査読有り

Saito, Y; Yamaguchi, H; Uehara, Y; Machida, H; Norinaga, K

JOURNAL OF THE JAPAN INSTITUTE OF ENERGY 105 巻 ( 4 ) 頁： 85 - 95 2026年

Numerical Analysis of CO2 Deposition in a Sublimation Tank and Evaluation of Property Parameter Effects Open Access

Saito Y., Yamaguchi H., Uehara Y., Machida H., Norinaga K.

Nihon Enerugi Gakkaishi Journal of the Japan Institute of Energy 105 巻 ( 4 ) 頁： 85 - 95 2026年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nihon Enerugi Gakkaishi Journal of the Japan Institute of Energy

CO<inf>2</inf> deposition under low-pressure conditions plays a key role in sublimation-based CO<inf>2</inf> separation processes; however, numerical studies on this phenomenon remain limited. In this study, CO<inf>2</inf> deposition behavior was investigated using a combination of a global tank-scale model and a local model that resolves the growth of the dry-ice layer. The global model evaluated heat transfer and fluid flow inside the tank using CO<inf>2</inf> properties corresponding to 100 kPa and 1 kPa, while the local model analyzed the growth of the deposited layer and its influence on the near-wall temperature. Experiments conducted under reduced-pressure conditions provided two key datasets—the temporal evolution of gas temperature near the cold plate and the growth of the dry-ice layer—which were used as reference indicators for comparison with the simulations. Although the simulations reproduced the initial temperature decrease, they failed to capture the subsequent temperature rise observed experimentally, suggesting that heat release associated with CO<inf>2</inf> deposition significantly affects the thermal behavior. When this heat release was incorporated as an additional boundary condition, the characteristic temperature rise observed in the experiments was successfully reproduced. These results clarify the respective roles and limitations of the global and local models in representing CO<inf>2</inf> deposition behavior and provide guidance for developing more accurate numerical models.

DOI： 10.3775/jie.105.85

Mechanistic study on the roles of heteroatoms in Ni-based dual-atom catalysts for electrochemical CO2 reduction 査読有り Open Access

Park G.D., Norinaga K.

Carbon Resources Conversion 2026年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

The intrinsic catalytic activity of single-atom catalysts (SACs) can be enhanced by incorporating other elements. However, understanding the roles of these heteroatoms is crucial for maximizing catalytic efficiency. In this study, we focused on the electrochemical CO<inf>2</inf> reduction reaction (CO<inf>2</inf>RR) over Ni-based dual-atom catalysts (DACs) containing Zn or Mn using in situ Raman spectroscopy and ab initio molecular dynamics simulations. The NiZn DAC achieved a CO faradaic efficiency of > 99.8% up to a current density of − 300 mA cm−2. Compared with the Ni SAC and NiMn DAC, the NiZn DAC more effectively facilitated electron transfer by tuning the electronic structure of the catalytically active Ni center, stabilizing the chemisorbed CO<inf>2</inf> intermediates, and accelerating proton transfer by biasing the electron density of the chemisorbed CO<inf>2</inf> intermediates. This study provides insights into the roles of heteroatoms in catalytic activity and will aid the development of highly efficient catalysts.

DOI： 10.1016/j.crcon.2026.100446

O-23　非滅菌メタン発酵残渣を用いたバイオエタノール生成査読有り

谷村あゆみ, 角澤教子, 小長谷耕平, 藤乗隆行, 廣部智己, 菊地亮太, 則永行庸

バイオマス科学会議発表論文集 21 巻 ( 0 ) 頁： 49 - 50 2025年11月

Facile Synthesis and Insight of Atomically Dispersed Ni Catalyst on N-Doped Carbonized Lignin for Highly Efficient Electrochemical CO2 Reduction to CO (vol 16, e202300530, 2023) 査読有り Open Access

Park, GD; Sirisomboonchai, S; Norinaga, K

CHEMSUSCHEM 18 巻 ( 17 ) 2025年9月

Acetylene formation via oxidative coupling of methane over monolithic Pt/ Al2O3 and Pt/ZrO2 catalysts 査読有り Open Access

Schardt, S; Çelik, A; Bastian, S; Sirisomboonchai, S; Nakamura, M; Norinaga, K; Lott, P

APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE 23 巻 2025年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applications in Energy and Combustion Science

This study investigates the influence of key operational parameters – including space velocity, feed gas dilution with nitrogen, and the carbon-to-oxygen (C:O) ratio – on monolithic Pt/Al₂O₃ and Pt/ZrO₂ catalysts for the oxidative coupling of methane (OCM). Optimal operating conditions were identified that yielded high C₂ selectivities, with a notably large share of acetylene. Under ideal conditions, a Pt/ZrO₂ catalyst achieved a maximum C₂ selectivity of 11.3 %, with 84 % acetylene contribution and approximately 90 % methane conversion. Zirconia was found to be a superior support material compared to alumina in terms of catalyst stability and longevity. A number of characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were applied and revealed significant morphological and structural changes in both catalyst types, induced by the harsh reaction conditions with temperatures exceeding 1200 °C. These findings contribute to the advancement of more robust catalyst formulations and optimized process conditions for the OCM reaction.

DOI： 10.1016/j.jaecs.2025.100357

Ethanol production from non-sterile methane fermentation residues for waste-to-biofuel conversion 査読有り Open Access

Tanimura, A; Kakuzawa, N; Obase, K; Tojo, T; Hirobe, T; Kikuchi, R; Norinaga, K

BIORESOURCE TECHNOLOGY REPORTS 31 巻 2025年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Bioresource Technology Reports

Effective valorization of food waste is essential for sustainable resource management. Methane fermentation residues, a byproduct of biogas production from food waste, are typically used as liquid fertilizer. However, their full potential as bioresource substrates remains underexplored. This study investigated the feasibility of producing bioethanol from non-sterile methane fermentation residues mixed with beverage waste under realistic, low-input conditions. Four sucrose-fermenting yeast strains were evaluated for ethanol production in a non-sterile medium composed of residue and deteriorated beverage (1:1, v/v). Ethanol was detected only under the non-sterile condition, not in filter-sterilized controls, suggesting that native microbial populations did not inhibit—and may have enhanced—fermentation. Saccharomyces pastorianus NBRC 11024T achieved the highest ethanol yield (27.4 g/L), reaching 89.4 % of the theoretical maximum within 48 h. Fermentation efficiency declined when the residue ratio exceeded 70 %, indicating possible inhibition due to nitrogen or volatile fatty acid accumulation. 16S rRNA amplicon sequencing revealed a marked shift in microbial community structure, with Leuconostoc species dominating at later stages. These findings suggest that methane fermentation residues can be used as functional co-substrates for ethanol production and may actively contribute to favorable fermentation conditions. In addition, commercially available beverages were shown to be a suitable model for waste beverages and provided practical insights into real-world applications. This approach offers a scalable, decentralized strategy for low-cost ethanol production and contributes to the development of circular bioresource systems.

DOI： 10.1016/j.biteb.2025.102285

P-4-5　単管式伝熱管を用いたCO2昇華槽内の温度分布の予測査読有り

千賀香菜子, 田代元太郎, 山口博泰, 上原友輔, 町田洋, 則永行庸, 齋藤泰洋

日本エネルギー学会大会講演要旨集 34 巻 ( 0 ) 頁： 224 - 225 2025年7月

液化天然ガスの極低温を利用する大気中二酸化炭素直接回収技術Cryo-DAC®の研究開発査読有り

則永行庸

日本エネルギー学会機関誌えねるみくす 104 巻 ( 4 ) 頁： 381 - 386 2025年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本エネルギー学会

本稿では，液化天然ガス（LNG）の未利用冷熱を活用して大気中の二酸化炭素（CO2）を直接回収する技術「Cryo-DAC®」の概要と，その開発状況について紹介する。Cryo-DAC®は，LNGの極低温を利用して気体のCO2を固体（ドライアイス）へと相転移させ，この過程で生じる減圧環境を用いてCO2を吸収したアミン系吸収液からCO2を再生する点に特徴がある。これにより従来必要とされていた加熱操作が不要で，エネルギー消費を抑えたCO2回収が可能となるポテンシャルを有する。現在，プロセスのスケールアップに向けて，コンセプト実証を目的としたベンチスケール装置の運転を開始している。

DOI： 10.20550/jieenermix.104.4_381

Numerical investigation of polycyclic aromatic hydrocarbons (PAHs) and soot formation from various coals in a two-stage entrained flow gasifier with detailed chemistry 査読有り

Li, TL; Fukumoto, K; Zhang, LJ; Lin, YX; Choi, C; Machida, H; Norinaga, K

JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 188 巻 2025年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Analytical and Applied Pyrolysis

The substitution of air with O<inf>2</inf>/CO<inf>2</inf> atmosphere is a promising solution for CO<inf>2</inf> recirculation during coal gasification. However, a comprehensive understanding on the formation mechanism of PAHs and soot under different conditions is necessary to reduce their emissions. This work presents simulation results of a two-stage entrained flow coal gasifier in a 250 MW industrial-scale plant using detailed chemistry. The influences of reductor temperature (1000–1200 ℃) and coal types (bituminous coal, sub-bituminous coal, and lignite) on PAHs and soot formations from the coal volatiles in the reductor were simulated through a detailed chemical kinetic model under air and O<inf>2</inf>/CO<inf>2</inf> atmospheres. Results show that 2- and 3-ring aromatics are main PAHs products. Rising temperature has inhibitory effects on PAHs formation, especially for lignite. The O<inf>2</inf>/CO<inf>2</inf> condition reduces the PAHs yield compared with the air condition. Rate of production analysis reveals that conversion of major PAHs occurs mainly between PAHs and their radicals. Vinyl-naphthyl radical and indenyl radical play an important role in the acenaphthylene conversion. In addition, soot production increases with a higher temperature under both air and O<inf>2</inf>/CO<inf>2</inf> conditions. The O<inf>2</inf>/CO<inf>2</inf> condition effectively suppressed soot production through a weaker HACA surface growth route than the air condition. lignite produces the least soot, and sub-bituminous coal produces the most. This study deeply reveals the formation mechanisms of PAHs and soot in a two-stage entrained flow gasifier through detailed chemical kinetic modeling, giving an insight into the complex PAHs and soot formations to assess the design and the operating condition of gasifier with O<inf>2</inf>/CO<inf>2</inf> injection.

DOI： 10.1016/j.jaap.2025.107027

Coal Gasification in a Two-Stage Entrained Flow Gasifier under O2/CO2 Conditions 査読有り

Li, TL; Choi, C; Fukumoto, K; Machida, H; Norinaga, K

ENERGY & FUELS 39 巻 ( 20 ) 頁： 9345 - 9358 2025年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

Coal gasification in industrial gasifiers faces challenges related to tar and soot formation, which affect performance and emissions. This study proposes a new numerical approach for simulating coal gasification in a two-stage entrained flow gasifier under different O<inf>2</inf>/CO<inf>2</inf> ratios-blown conditions. The modeling framework incorporates a static simulation for the combustor and couples a multistep coal devolatilization model with an expanded gas-phase reaction model in the reductor. Model validation against experimental data showed prediction accuracies ranging from 4 to 20% for the devolatilization model and from 3 to 25% for the gas-phase reaction model across various species. The validated framework was employed to investigate the effect of varying O<inf>2</inf>/CO<inf>2</inf> ratios in gasifying agents on the gasification performance. Results showed that increasing the O<inf>2</inf>/CO<inf>2</inf> ratio from 30% to 50% increased H<inf>2</inf> production from 3.69% to 13.03% and CO from 34.40% to 55.04% while reducing CO<inf>2</inf> from 48.27% to 19.96%. Higher O<inf>2</inf>/CO<inf>2</inf> ratios inhibited soot formation but increased the tar yield, although the final tar concentration remained well below 1 mg/Nm3. This study highlights the potential of using oxy-fuel gasification with CO<inf>2</inf> recirculation for optimizing syngas quality and advancing CO<inf>2</inf> capture, offering valuable insights for industrial gasifier design and operation within oxy-fuel IGCC systems.

DOI： 10.1021/acs.energyfuels.5c00098

Mechanism investigation of direct electrochemical reduction of CO2-loaded 2-(ethylamino)ethanol solution into CO 査読有り

Dai, RC; Zhang, LJ; Tran, KVB; Sirisomboonchai, S; Machida, H; Norinaga, K

SEPARATION AND PURIFICATION TECHNOLOGY 355 巻 2025年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Separation and Purification Technology

Carbon capture and utilization (CCU) has attracted considerable interest recently as CO<inf>2</inf> emission and global warming have greatly affected various aspects of the environment, economy, and society. However, energy consumption during CCU must be substantially reduced. In this study, we propose an alternative approach using electrochemical reduction to directly convert CO<inf>2</inf>-loaded amine solutions into CO. The effects of the electrodes, temperature, potential, and CO<inf>2</inf> loading on the Faradaic efficiency (FE) of CO were comprehensively investigated. The Ag NPs/CP electrode showed good catalytic performance on the electrochemical reduction of CO<inf>2</inf>-loaded amine solution to CO. By comparing the chemical composition in the solution before and after the electrochemical reaction, we determined that the main source of CO might be free CO<inf>2</inf>, which is mainly converted from bicarbonate rather than carbamate. In addition, electrochemical impedance spectroscopy was used to investigate the resistance during the reaction. The electric double-layer was found over the electrode surface when different amine solutions were used as the electrolyte. The spatial structure of ammonium cations and carbamate plays a key role in the FE of CO in this process.

DOI： 10.1016/j.seppur.2024.129575

Design of an efficient CO2 methanation process and techno-economic analysis with CO2 capture from the flue gas of automotive shredder residue 査読有り Open Access

Wasnik, CG; Nakamura, M; Machida, H; Ito, J; Shiratori, K; Norinaga, K

CHEMICAL ENGINEERING JOURNAL 507 巻 2025年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Journal

Recycling and utilizing automotive shredder residue (ASR) is necessary for realizing a sustainable automotive industry. This study conducted a feasibility analysis using a process simulator for Case I, where fuel gas is produced through the gasification of ASR followed by combined heat and power generation using a gas engine, CO<inf>2</inf> capture from exhaust gas through chemical absorption, and production of synthetic methane (CH<inf>4</inf>) using the captured CO<inf>2</inf> and renewable hydrogen produced via water electrolysis powered by renewable energy sources. This process produces not only CH<inf>4</inf> but also surplus electricity, which can be used to produce H<inf>2</inf> or power adjacent equipment. Case II, where fuel gas obtained from ASR gasification was directly methanated, was considered for comparison. This study compared the economic potential of both processes for kiln-type ASR gasification that can process 1,200 kg-ASR/h to produce 3,350 Nm3/h of fuel gas. Case I produced 4,800 tons/year of CH<inf>4</inf> with an energy efficiency of 46.5 %, whereas Case II produced 2,720 tons/year. The levelized production cost of methane in 2050 can be estimated at $1,241/ton and $1,568/ton for Cases I and II, respectively, which are lower than the expected cost of natural gas in market environments by 2050. This study highlights the potential of ASR-derived CO<inf>2</inf> methanation as a carbon–neutral technology that can effectively achieve carbon conversion while producing high-value synthetic methane.

DOI： 10.1016/j.cej.2025.160737

CO2 methanation over low-loaded Ni-M, Ru-M (M = Co, Mn) catalysts supported on CeO2 and SiC 査読有り Open Access

Wasnik, CG; Nakamura, M; Shimada, T; Machida, H; Norinaga, K

CARBON RESOURCES CONVERSION 8 巻 ( 1 ) 2025年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

The concentration of the major greenhouse gas CO<inf>2</inf> is rapidly increasing in the atmosphere, leading to global warming and a range of environmental issues. An efficient circulation and utilization of CO<inf>2</inf> is critical in the current environmental context. Methanation, an exothermic process, emerges as a critical strategy for effective CO<inf>2</inf> utilization. On this front, there is a significant demand for rational design of catalysts that maintain high activity and methane selectivity over a wide temperature range (250–550 °C). The catalyst that can promise a consistent reaction even at 500 °C under an atmospheric pressure is thus obliged. The present study investigated bimetallic catalysts with SiC, which is known for its exceptional thermal conductivity, and CeO<inf>2</inf>, which is characterized by its CO₂ affinity, as base materials. We incorporated Ni-M and Ru-M (M = Co and Mn) as the active metals, each loaded at 2 %. Impressively, with merely 20 mg, the Ni-Co/SiC catalyst achieved a CO<inf>2</inf> conversion rate of 77 % and CH₄ selectivity of 88 % at 500 °C, in a fixed-bed tubular reactor system with conditions of H<inf>2</inf>/CO<inf>2</inf> = 4, a total flow rate of 70 ml min−1, and a steady GHSV of 12,000 h−1. Moreover, 2Ni-2Co/CeO<inf>2</inf> catalyst demonstrated exceptional performance with a 76 % conversion of CO<inf>2</inf> and a 83 % selectivity for CH<inf>4</inf>, all under identical conditions. The catalyst's durability was confirmed by a subsequent 40-hour stability test, which showed only a 3–5 % degradation. The developed catalysts were comprehensively characterized by BET/BJH, CO pulse chemisorption, H<inf>2</inf>-TPR, HAADF-STEM-EDS, SEM-EDS and XRD etc. to unveil their physicochemical and surface traits. It was found that Co and Mn, when integrated, effectively restrained the agglomeration of Ni and Ru particles, ensuring optimal metal dispersion on the support. In conclusion, our synthesized bimetallic catalysts shown a sustained catalytic capability, even in the high-temperature environment.

DOI： 10.1016/j.crcon.2024.100241

A New Method to Observe the Internal Amine Distribution in an Amine-Functionalized Resin Sorbent Particle 査読有り

Xu, CH; Liu, PB; Peng, YL; Dou, MY; Jiang, QQ; Jia, XH; Zhang, YM; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 64 巻 ( 10 ) 頁： 5596 - 5601 2025年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

Understanding the amine distribution within solid amine sorbents is crucial for enhancing their amine utilization and ultimately improving the CO<inf>2</inf> adsorption capacity. However, suitable characterization methods are lacking. To address this, a novel method was proposed to visualize the distributions of total and accessible amine content within the sorbent particles. In this method, SO<inf>2</inf> was selected to label the accessible amine, while scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) were used to measure the nitrogen and sulfur content, which were further used to calculate the total amine and accessible amine content, respectively. By this method, the total amine content is found to be evenly distributed, which is also higher than the accessible amine content due to the utilization of nitrogen for cross-linking and the diffusion resistance within the particles. For particle sizes larger than a critical size, accessible amine content is higher near the wall and lower at the core. This gradient becomes less pronounced as particle size decreases and becomes uniform when particle size is below this critical size. Therefore, reducing the particle size of solid amine sorbents to below the critical size range (e.g., 250-338 μm in this study) can effectively enhance CO<inf>2</inf> adsorption capacity by maximuming the accessible amine cont within the sorbent particles.

DOI： 10.1021/acs.iecr.4c05007

Observation and kinetic modeling of carbon dioxide deposition under reduced pressures at cryogenic temperatures 査読有り Open Access

Xiao, SW; Hirayama, M; Machida, H; Norinaga, K

CHEMICAL ENGINEERING SCIENCE 305 巻 2025年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

Liquefied natural gas (LNG) is typically vaporized through heat exchange with seawater or other sources and used as city gas or power generation fuel, but its cold energy remains underutilized. This study proposes a new CO<inf>2</inf> capture process leveraging LNG's cryogenic temperatures to create a vacuum environment, recovering CO<inf>2</inf> from amine-based solutions as dry ice. CO<inf>2</inf> deposition under cryogenic and vacuum conditions was observed, and a deposition rate model was developed. In the experiment, liquid nitrogen circulated through the tube side of a glass vertical single-tube shell-and-tube heat exchanger (230 mm long), while CO<inf>2</inf> was supplied to the shell side. CO<inf>2</inf> was deposited on the outer surface of a 5-mm diameter tube, with its growth rate measured by a laser displacement sensor. At 293 K and pressures of 140–1000 Pa, experimental results matched a rate model based on energy balance and mass transfer.

DOI： 10.1016/j.ces.2024.121177

Nickel/Zirconia-Catalyzed CO2 Methanation in Differential and Integral Fixed-Bed Reactors: Experimental and Computational Fluid Dynamics Studies 査読有り Open Access

Shimada, T; Nakamura, M; Fukumoto, K; Ibrahim, M; Wasnik, CG; Machida, H; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 64 巻 ( 3 ) 頁： 1473 - 1487 2025年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

Isothermal conditions and a chemical-kinetics-limited rate should be maintained when measuring the reaction rates of gases on solid catalysts. However, in highly exothermic reactions─such as the Sabatier reaction─temperature variations within the catalyst bed make it challenging to achieve isothermality. In this study, temperature changes in a Ni/ZrO<inf>2</inf> catalyst bed were minimized using α-Al<inf>2</inf>O<inf>3</inf> diluent and high gas hourly space velocities (GHSVs) to achieve low feed gas conversion (differential conditions: 0.9 MPa; 523-873 K; GHSV = 7600-30,000 L/h/g cat). The temperature profile within the catalyst bed was obtained by coupling a previously reported kinetic model with three-dimensional computational fluid dynamics (CFD) simulations. Experiments were also conducted under integral conditions at low GHSVs, resulting in high conversion rates and heat release. CFD simulations accurately reproduced the experimental feed gas conversion and temperature, suggesting that the CFD-simulation-guided kinetic parameters appropriately predicted the methanation characteristics at practically relevant high conversion rates.

DOI： 10.1021/acs.iecr.4c03789

CFD simulation of crude oil fouling from laboratory- to industrial-scale heat exchangers using a weak coupling approach 査読有り

Fukumoto, K; Zhang, W; Choi, C; Tang, F; Machida, H; Norinaga, K

APPLIED THERMAL ENGINEERING 258 巻 2025年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Thermal Engineering

Crude oil fouling is described as an accumulation of unwanted materials such as asphaltene and metallic salt on a heat transfer surface in a pre-heat train of the crude distillation unit in oil refineries, causing an economic loss of 1–1.2 billion U.S. dollars per year in 2019. Computational fluid dynamics is one of the useful simulation tools for numerical research on this topic. However, crude oil fouling is a long-term phenomenon; therefore, the time scale is longer than general computational fluid dynamics problems. The fouling layer in oil refineries grows over several months to several years despite the small pipe diameter of several or several tens of millimetres. For this reason, it is not easy to satisfy the Courant–Friedrichs–Lewy condition. To overcome this problem, we developed a new algorithm based on a weak coupling approach, validated this scheme, and exhibited the application of this technology. In the new algorithm, momentum and pressure fields and enthalpy and mass fraction fields are solved separately. The algorithm was implemented as FoulingFOAM, a crude oil fouling simulator based on OpenFOAM v2006. Then, the solver was first validated with the lab-scale measurements, showing good agreement with the experimental data. Next, industrial-scale data in the two refineries were simulated for validation. It was possible to predict the peak fouling resistance against time. Finally, for both lab- and industrial-scale simulations, the predictions of our numerical tool showed that fouling resistance increased with higher wall temperature, lower crude oil velocity, and higher concentration of fouling species, which were identical to previous measurements. Hence, we concluded that the weak coupling approach is promising for investigating crude oil fouling problems.

DOI： 10.1016/j.applthermaleng.2024.124614

自動車破砕残渣(ASR)排ガス中CO2を用いたメタネーションプロセスの最適化と技術経済性評価

WASNIK G. Chopendra, 中村真季, 町田洋, 伊藤淳二, 白鳥一幸, 則永行庸

動力・エネルギー技術の最前線講演論文集 : シンポジウム 2025.29 巻 ( 0 ) 頁： B243 2025年

1-07　フルフラール水素化によるテトラヒドロフルフリルアルコール合成における技術経済性分析査読有り

上原友輔, 李乔, 町田洋, 則永行庸

石炭科学会議発表論文集 61 巻 ( 0 ) 頁： 14 - 15 2024年10月

1-03　ペロブスカイト触媒を用いた二酸化炭素の電解還元によるエチレンへの転換査読有り

スチャダシリソンブーンチャイ, 則永行庸

石炭科学会議発表論文集 61 巻 ( 0 ) 頁： 6 - 7 2024年10月

Design and Optimization of Large-Scale Green Liquid Hydrogen Production Integrated with Heat Recovery and Absorption Precooling 査読有り

Li, Q; Machida, H; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 63 巻 ( 44 ) 頁： 19063 - 19075 2024年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

Liquid hydrogen (LH<inf>2</inf>) presents a viable solution for energy storage and transportation, particularly when produced by using renewable electricity. In this study, the energy efficiency of large-scale PEM water electrolysis for hydrogen production was investigated to be 59.74%, with the levelized electricity cost of hydrogen of 57.48 kWh/kg. To recover the waste heat from the PEM electrolyzer, two heat integration approaches have been proposed: the organic Rankine cycle (ORC) and the absorption refrigeration cycle (ARC). The ORC converted waste heat into electricity, while the ARC generated cold energy to precool the refrigerant, alongside electricity generation, both of which reduced energy consumption in the hydrogen liquefaction process. Subsequently, the process parameters were optimized through Matlab with the Mesh Adaptive Direct Search algorithm aimed at minimizing the specific energy consumption (SEC) of hydrogen liquefaction integrated with ORC or ARC, resulting in SECs of 6.76 and 6.61 kWh/kg LH<inf>2</inf>, with 21.33% and 22.87% reductions compared with the liquefaction process without heat recovery, respectively. The corresponding exergy efficiencies were 56.96% and 57.16% for the liquid hydrogen production process, with 86.69% and 87.73% for the hydrogen liquefaction process, respectively.

DOI： 10.1021/acs.iecr.4c02383

P-4-5　CO2昇華槽内での伝熱現象における解析条件の検討査読有り

山口博泰, 上原友輔, 町田洋, 則永行庸, 齋藤泰洋

日本エネルギー学会大会講演要旨集 33 巻 ( 0 ) 頁： 244 - 245 2024年7月

6-2-4　窒素ドープ型バイオチャーに高分散したニッケル触媒による高効率CO2電解還元査読有り

Park Gi-Dong, Suchada Sirisomboonchai, 則永行庸

日本エネルギー学会大会講演要旨集 33 巻 ( 0 ) 頁： 166 - 167 2024年7月

6-2-2　自動車シュレッダーダスト処理ガスを原料とするメタン合成プロセスに関する検討査読有り

中村真季, Li Qiao, Chopendra G. Wasnik, 則永行庸

日本エネルギー学会大会講演要旨集 33 巻 ( 0 ) 頁： 162 - 163 2024年7月

6-2-3　酸化セリアや炭化ケイ素に担持した二元系金属触媒によるCO2メタネーションに関する検討査読有り

Chopendra G. Wasnik, 中村真季, 島⽥⼤輝, 町田洋, 則永行庸

日本エネルギー学会大会講演要旨集 33 巻 ( 0 ) 頁： 164 - 165 2024年7月

環境リサイクル部会　座談会査読有り

野田玲治, 則永行庸, 伏見千尋, 榎本啓士, 細貝聡, 太田智久

日本エネルギー学会機関誌えねるみくす 103 巻 ( 4 ) 頁： 422 - 431 2024年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本エネルギー学会

2024年４月に旧ガス化部会と旧リサイクル部会が合併し，環境リサイクル部会が発足しました。新部会発足にあたり，幹事の皆様に，簡単な自己紹介後，環境リサイクル部会が関わる脱炭素，サーキュラーエコノミー等について座談会を行い，さらに今後の部会での活動抱負についてもお話をお聞きしました。なお，今回の座談会は，予定の合った幹事で開催しました。

DOI： 10.20550/jieenermix.103.4_422

LNG Oxy-Fuel Power and Green Methanol Poly Generation Systems Associated with CO2 Condensation Capture: Techno-Economic Environmental Assessment 査読有り

Li, Q; Machida, H; Feng, ZM; Norinaga, K

ENERGY & FUELS 38 巻 ( 14 ) 頁： 13089 - 13103 2024年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

To achieve energy-environment synergy and sustainability, this study proposes a poly generation system that integrates the energy release process of liquefied natural gas (LNG) oxy-fuel power generation with the energy storage process of green methanol synthesis from renewable energy. In this system, oxygen, the byproduct of water hydrolysis to hydrogen, can support LNG oxy-fuel power generation; while the cold energy released during LNG regasification can serve as a cold source for carbon capture, the captured CO<inf>2</inf> can be utilized as the carbon source for methanol synthesis, thus realizing cleaner methanol production and an efficient power generation process with near-zero carbon emission. Following the process design, the parameters were optimized with minimum levelized production cost of methanol and electricity as the objective function through Matlab using the “MADS” algorithm, resulting in 683.79 $/tonne and 68.05 $/MW h, respectively, with overall exergy efficiency of 50.28%. Notably, as green methanol synthesis requires additional CO<inf>2</inf>, a reduction of 2272.59 kg/h can be achieved. The study concludes that the novel poly generation process is superior in exergy efficiency and CO<inf>2</inf> capture and utilization but inferior in high production costs.

DOI： 10.1021/acs.energyfuels.4c01250

Environmental-friendly extraction of di(2-ethylhexyl) phthalate from poly (vinyl chloride) using liquefied dimethyl ether 査読有り

Wang, T; Kanda, H; Kusumi, K; Mei, L; Zhang, LJ; Machida, H; Norinaga, K; Yamamoto, T; Sekikawa, H; Yasui, K; Zhu, L

WASTE MANAGEMENT 183 巻頁： 21 - 31 2024年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Waste Management

Poly(vinyl chloride) (PVC) is one of the most widely used plastics. However, a major challenge in recycling PVC is that there is no economical method to separate and remove its toxic phthalate plasticizers. This research made a breakthrough by extracting PVC with liquefied dimethyl ether (DME) and successfully separating the plasticizer components. Nearly all (97.1 %) of the di(2-ethylhexyl) phthalate plasticizer was extracted within 30 min by passing liquefied DME (285 g) through PVC at 25 °C. The compatibility of PVC with organic solvents, including liquefied DME, was derived theoretically from their Hansen solubility parameters (HSP), and actual dissolution experiments were conducted to determine the optimal PVC solvents. A liquefied DME mixture was used to dissolve PVC, and the extract was diluted with ethanol to precipitate the dissolved PVC. We demonstrated that liquefied DME is a promising method for producing high quality recycled products and that the process retains the fundamental properties of plasticizers and PVC without inducing degradation or depolymerization. Because of its low boiling point, DME can be easily separated from the solute after extraction, allowing for efficient reuse of the solvent, extracted plasticizer, and PVC. DME does not require heat and produces little harmful wastewater, which significantly reduces the energy consumption of the plasticizer additive separation process.

DOI： 10.1016/j.wasman.2024.04.050

PubMed

Energy optimization of a non-aqueous solvent CO2 absorption system with pressure swing regeneration 査読有り

Chairunnisaa; Zhou, YX; Wu, YT; You, C; Thu, K; Miyazaki, T; Uehara, Y; Machida, H; Norinaga, K

INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL 135 巻 2024年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Greenhouse Gas Control

This study focuses on optimizing the energy requirement in the post-combustion CO<inf>2</inf> capture system using pressure swing regeneration through a model-based design (MBD). The simulation results highlight the significant impact of CO<inf>2</inf> recovery, inlet gas and liquid flow rate, and CO<inf>2</inf> concentration in the flue gas on the overall energy demand of the system. Moreover, an investigation into the de-sublimation chamber was undertaken, revealing a relationship between dry ice formation and the heat transfer between the LNG stream and CO<inf>2</inf> in the heat exchanger. The parametric analysis study reveals that the sensible heat of the lean solvent is significantly influenced by the CO<inf>2</inf> concentration in the liquid, consequently affecting the overall system energy. According to the results, the utilization of cold energy from LNG could save 80 % of the total energy requirement. The optimization results found the best working condition, which consumes energy of 0.190 GJ/ton CO<inf>2</inf>, 31 % lower than the basic scenario.

DOI： 10.1016/j.ijggc.2024.104154

High-Throughput CO2 Solubility Measurement in Miscible and Liquid-Liquid Phase Separation Types of Amine Solvent Using Headspace Gas Chromatography 査読有り

Tran, KVB; Yanase, K; Rao, TU; Hirayama, M; Norinaga, K; Machida, H

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 63 巻 ( 13 ) 頁： 5823 - 5832 2024年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

CO<inf>2</inf> solubility is one of the key factors in evaluating not only the efficiency of the absorbent but also the energy consumption of the CO<inf>2</inf> capture process from flue gas. In this study, a system namely headspace gas chromatography (HS-GC), which is a combination of gas chromatography (GC-3200, GL Sciences) and a headspace autosampler (Turbomatrix HS16, PerkinElmer), was developed to measure the CO<inf>2</inf> solubility of amine solutions. The equilibrium time and calibration curve of this system were checked and compared with those of the literature data. The developed system showed high reproducibility with reference CO<inf>2</inf> solubility data of benchmark amine solutions. Distinct from conventional measurement methods of CO<inf>2</inf> solubility, high-throughput CO<inf>2</inf> solubility measurement by HS-GC shows its advantages such as a small amount sample requirement, rapid achievement of equilibration time, automation of sample exchange, and high reproducibility, which is superior in the amine solvent screening phase. Moreover, this system can evaluate new types of CO<inf>2</inf> capture solvents, including the phase separation solvent. By acquiring continuous data, the inflection point in the solubility curve indicated by phase separation was observed. The absorption heat estimated from those CO<inf>2</inf> solubility curves measured by this system also agrees well with the experimental data.

DOI： 10.1021/acs.iecr.3c03314

Design and Optimization for Sustainable Synthesis of Tetrahydrofurfuryl Alcohol by Furfural Hydrogenation: Kinetic and Techno-economic Investigations 査読有り

Li Q., Rao T.U., Uehara Y., Machida H., Huo Z., Norinaga K.

ACS Sustainable Resource Management 1 巻 ( 2 ) 頁： 316 - 327 2024年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Sustainable Resource Management

To address energy challenges, we propose synthesizing tetrahydrofurfuryl alcohol from biomass-derived furfural and hydrogen produced through electrolysis. Building upon prior research [Energy Convers. Manage.2022 2022, 265, 115736], the kinetic parameters of the developed catalysts for two-step reactions including furfural hydrogenation to furfuryl alcohol and tetrahydrofurfuryl alcohol were investigated, in which the activation energies were E<inf>a1</inf>= 29.35 and E<inf>a2</inf>= 38.97 kJ/mol, respectively. Subsequently, we designed the complete production process, including hydrogen generation, furfural hydrogenation, and tetrahydrofurfuryl alcohol purification. To enhance economic efficiency by minimizing energy consumption, the organic Rankine cycle-coupled heat pump was integrated into the process. Following the process design, the parameters were optimized with minimum levelized production cost of tetrahydrofurfuryl alcohol as the objective function by Matlab using the “MADS” algorithm, which resulted in 1855.85 $/tonne with 76.62 % overall energy efficiency. Finally, sensitivity analyses were performed to determine the cost factors affecting the economic indicators. This work provides a sustainable and profitable process route for producing high-quality chemicals from biomass, particularly in the context of potential future fossil energy crises.

DOI： 10.1021/acssusresmgt.3c00084

Design and optimization of the flexible poly- generation process for methanol and formic acid from CO2 hydrogenation under uncertain product prices 査読有り

Li, Q; Machida, H; Ren, XS; Feng, ZM; Norinaga, K

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 54 巻頁： 635 - 651 2024年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Hydrogen Energy

During the design of the carbon capture and hydrogen storage process, a static CO<inf>2</inf> hydrogenation poly-generation process for methanol and formic acid synthesis was developed, thereby reducing recycling flow and feedstock losses in the single methanol synthesis process and increasing product diversity. Additionally, a novel flexible poly-generation process was proposed as the product prices fluctuated with the market environment throughout the plant's life cycle. For the static poly-generation process, a mixed integer nonlinear programming model was established, followed by the Mesh Adaptive Direct Search algorithm to determine the optimal parameter design. For flexible processes, with the unscented transform tool, a two-stage optimization strategy is proposed for obtaining optimal design and operating parameters that are computationally tractable. With an input CO<inf>2</inf> flow rate of 200 kmol/h, the results show (1) the static process with an optimal Return On Investment of 13.05%, a fixed investment cost of $ 34.14 × 106, and an annual net profit of 4.46 × 106 $/year; and (2) the flexible process, in which the flexibility indices of the methanol and formic acid production units are 1.088 and 1.194, respectively, resulting the fixed investment cost increase to $ 39.19 × 106, an increase of 14.79%. Accordingly, the annual net profit increased by 8.97% to 4.86 × 106 $/year, while the Return On Investment decreased by 4.67%–12.44%. For investment decision-makers, the flexible poly-generation process can achieve higher profits and reduce potential market risks when they have adequate financing.

DOI： 10.1016/j.ijhydene.2023.01.205

Regulation of temperature distribution in fixed bed reactor for CO2 methanation through "CHESS" monolith structure catalyst 査読有り

Zhang, W; Lin, YX; Zhang, YM; Li, TL; Li, JZ; Chen, ZW; Norinaga, K

APPLIED THERMAL ENGINEERING 236 巻 2024年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Thermal Engineering

CO<inf>2</inf> methanation suffers from the problem of temperature runaway phenomenon due to its exothermic nature. To mitigate this issue, optimizing catalyst structure becomes crucial. This work established numerical models to investigate the CO<inf>2</inf> methanation reaction and heat/mass transfer process in the reactor with porous pellet and monolithic catalysts. Results show that the reactor with porous pellets has the lowest carbon conversion per unit pressure drop due to its large total pressure drop. In contrast, the reactor with monolith exhibits a much larger carbon conversion per unit pressure drop but a smaller absolute carbon conversion. Based on this, an improved “CHESS” monolith structure was proposed and improved, which not only maintains a high absolute carbon conversion (62.6 %) but also enhances the heat transfer process in CO<inf>2</inf> methanation. Moreover, compared with the reactor with porous pellets, the maximum temperature in the improved “CHESS” monolith was decreased by around 11.09 %.

DOI： 10.1016/j.applthermaleng.2023.121826

CFD simulation of CO2 methanation through the Sabatier reaction in a shell-and-tube reactor incorporating phase change on the shell side 査読有り

1-02　種々の石炭の噴流床ガス化におけるタールやすす生成特性の詳細化学反応速度モデルを用いた解析

李泰霖, 中村真季, 上原友輔, 町田洋, 則永行庸

石炭科学会議発表論文集 60 巻 ( 0 ) 頁： 4 - 5 2023年10月

1-08　二酸化炭素水素化反応器の成形触媒形状レベルで解像した数値流体力学解析査読有り

島田大輝, Lin Yixiong, 中村真季, 則永行庸

石炭科学会議発表論文集 60 巻 ( 0 ) 頁： 16 - 17 2023年10月

Fukumoto, K; Zhang, W; Mizoguchi, R; Lin, YX; Choi, C; Machida, H; Norinaga, K

FUEL 349 巻頁： 128126 - 128126 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel

This paper reports a computational fluid dynamics simulation of carbon dioxide (CO<inf>2</inf>) methanation via the Sabatier process in a shell-and-tube reactor, incorporating a water phase change simulation on the shell side using the volume of fluid (VOF) method. The essential heat removal factors and their mechanisms, such as the catalyst size, bed porosity, thermal conductivity, coolant flow rate, and coolant boiling, were primarily investigated. The computational code was a newly developed in-house version of ChtMultiRegionFOAM based on OpenFOAM v2006. This code can simulate catalyst-gas heat transfer, which is called the two-temperature model. The code was extended to new methanation and phase-change models based on the VOF method. The computational code was first validated using existing experimental data. After sufficient accuracy was confirmed, several parametric studies were conducted. Catalyst heat conductivity was the most influential factor among the catalyst-related parameters. The flow rate of the oil coolant significantly affected the cooling performance. Finally, the use of boiling water significantly reduced the coolant flow rate. Moreover, the cooling performance remained unchanged until the total heat release rate from the gas exceeded the total latent heat of the water.

DOI： 10.1016/j.fuel.2023.128126

Modeling the Chemical Structures of Coals with Different Classifications Using Mean Molecular Weights Open Access

Hata, Y; Hayashizaki, H; Takanohashi, T; Takahashi, T; Kanehashi, K; Norinaga, K

TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN 109 巻 ( 10 ) 頁： 792 - 801 2023年10月

Facile Synthesis and Insight of Atomically Dispersed Ni Catalyst on N-Doped Carbonized Lignin for Highly Efficient Electrochemical CO2 Reduction to CO 査読有り Open Access

Park, GD; Sirisomboonchai, S; Norinaga, K

CHEMSUSCHEM 16 巻 ( 16 ) 頁： e202300530 2023年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemsuschem

For the electrochemical CO<inf>2</inf> reduction reaction (CO<inf>2</inf>RR), the single-metal atom catalysts (SACs) on N-doped carbon are considered promising alternatives to conventional catalysts owing to their unique electrocatalytic properties. However, environmentally friendly methods to prepare SACs are still required. Herein, Ni SAC was synthesized using lignin derived from biomass whose structural and chemical properties render it suitable as both a base carbon matrix and a metal chelating agent. The coordination environment of active Ni−N<inf>x</inf> sites was readily manipulated by controlling thermal activation. The Ni SAC on lignin-derived N-doped carbon achieved an outstanding CO Faradaic efficiency of 98.2 % at −0.9 V vs. RHE, which is comparable to those of conventional SACs. Experimental results combined with DFT calculations demonstrate the optimal conditions for manufacturing Ni SAC which is highly selective for CO<inf>2</inf>-to-CO conversion and the effect of the electronic structure of Ni atom on CO<inf>2</inf>RR kinetics.

DOI： 10.1002/cssc.202300530

6-1-1 バイメタル被覆銅フォーム電極を用いた電気化学的CO2還元-酸素発生反応システムの構築査読有り

シリソンブーンチャイスチャダ, 町田洋, 則永行庸

日本エネルギー学会大会講演要旨集 32 巻 ( 0 ) 頁： 116 - 117 2023年8月

4-4-1 流体温度が昇華槽内の伝熱挙動に及ぼす影響査読有り

山口博泰, 上原友輔, 町田洋, 則永行庸, 齋藤泰洋

日本エネルギー学会大会講演要旨集 32 巻 ( 0 ) 頁： 90 - 91 2023年8月

4-5-1 製品価格の不確実性を考慮したCO2水素化によるメタノールとギ酸の柔軟なポリジェネレーションプロセスの設計と最適化☆ 査読有り

李喬, 町田洋, 則永行庸

日本エネルギー学会大会講演要旨集 32 巻 ( 0 ) 頁： 98 - 99 2023年8月

Insights into structure-performance relationship in radial flow fixed bed reactor for CO2 methanation 査読有り

Zhang, W; Lin, YX; Norinaga, K

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 48 巻 ( 64 ) 頁： 24594 - 24606 2023年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Hydrogen Energy

The extraction of petroleum and natural gas is often accompanied by a large number of associated gases, especially the high CO<inf>2</inf> content reservoirs facing the emission of a large amount of CO<inf>2</inf>. CO<inf>2</inf> methanation is recognized as one of the suitable candidates for CO<inf>2</inf> utilization to reduce the emission of CO<inf>2</inf>. Because of the highly exothermic nature of the reaction, however, it is very important to enhance the heat transfer process inside the reactor and inhibit the formation of hot spots. In the fixed bed reactor, the heat transfer in the radial direction is greatly limited compared with that in the axial direction. Thus, this work adopted the radial flow reactor to evaluate the CO<inf>2</inf> methanation process by the means of a numerical model based on OpenFOAM. Four types of radial flow reactor configurations, namely centrifugal Z-type, centrifugal Π-type, centripetal Z-type, and centripetal Π-type, were compared. The fluid flow, heat transfer, and reaction performances for these reactors were discussed under consistent operating conditions. Results show that the centrifugal Π-type structure has the most uniform flow field. In terms of heat transfer and reaction performance, the centripetal Z-type structure is the best among the four radial flow reactor configurations. These findings provide a theoretical basis and technical guidance for designing and developing radial flow reactors.

DOI： 10.1016/j.ijhydene.2023.03.343

Polycyclic aromatic hydrocarbons (PAHs) and soot formations under different gasifying agents: Detailed chemical kinetic analysis of a two-stage entrained flow coal gasifier 査読有り

Li, TL; Choi, C; Fukomoto, K; Machida, H; Norinaga, K

FUEL 343 巻頁： 127876 - 127876 2023年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel

The injection of CO<inf>2</inf> with coal into coal gasifier is a promising approach to achieve CO<inf>2</inf> recirculation. Predicting the formation and evolution of polycyclic aromatic hydrocarbons (PAHs) and soot during coal gasification is particularly important as their presence poses challenges to the gasifier operation and environment. However, the effect of CO<inf>2</inf> injection on their formation must be elucidated in more detail to optimize the gasifier design. This work investigates PAHs and soot formations in gas-phase reactions under different gasifying agents (Air, O<inf>2</inf>/CO<inf>2</inf>, O<inf>2</inf>/H<inf>2</inf>O) in a two-stage entrained flow coal gasifier using a detailed chemical kinetic model (DCKM). Under the O<inf>2</inf>/CO<inf>2</inf>– and O<inf>2</inf>/H<inf>2</inf>O-blown conditions, aromatics reforming was progressed whereas the yields of tar and soot were effectively suppressed. The benzene was observed as the most abundant PAHs species, followed by naphthalene and acenaphthalene. Regarding the relative oxygen concentration, the conversion behavior of aromatics was significantly influenced in the O<inf>2</inf>/CO<inf>2</inf>-blown condition, while the somewhat effect was found in the O<inf>2</inf>/H<inf>2</inf>O-blown condition. Tar yield peaked at 50% relative oxygen concentration in the O<inf>2</inf>/CO<inf>2</inf>-blown condition. The present finding may have practical significance in the O<inf>2</inf>/CO<inf>2</inf>-blown gasifier to facilitate CO<inf>2</inf> recirculation for the oxy-fuel IGCC system.

DOI： 10.1016/j.fuel.2023.127876

Facile pyridinization of bio-based furfural into 3-hydroxypyridines over Raney Fe catalyst 査読有り

Ren, DZ; Jiang, XL; Zhang, NH; Duo, J; Norinaga, K; Huo, ZB

BIOMASS CONVERSION AND BIOREFINERY 13 巻 ( 9 ) 頁： 8115 - 8121 2023年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Biomass Conversion and Biorefinery

Production of pyridine derivatives from bio-based feedstocks instead of fossil fuels is a promising strategy. The development of effective heterogeneous catalysts and mild reaction systems for pyridinization of renewable biomass derivatives remains a huge challenge. In this article, a direct and environment-friendly method was reported to produce 3-hydroxypyridine from bio-based furfural in water over a Raney Fe catalyst. Raney Fe exhibited an efficient catalytic performance for activation of the aldehyde group of furfural and afforded an 18.2% yield of 3-hydroxypyridine at 120 °C with ammonia as N source. The polymerization of furfural on the catalyst in hot water was the main cause of deactivation, which was verified by the scanning electron microscope (SEM), X-ray diffraction (XRD), and N<inf>2</inf> adsorption and desorption analysis. A possible mechanism for this reaction was also proposed. This study provides a new way for academia and industry to realize the synthesis of nitrogen-containing chemicals from biomass and its derivatives.

DOI： 10.1007/s13399-021-01802-5

CFD simulation of CVD reactors in the CH3SiCl3(MTS)/H2 system using a two-step MTS decomposition and one-step SiC growth models 査読有り Open Access

Ogawa, T; Fukumoto, K; Machida, H; Norinaga, K

HELIYON 9 巻 ( 4 ) 頁： e15061 2023年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Heliyon

In this study, we report on a computational fluid dynamics (CFD) simulation of the chemical vapor deposition reactor of silicon carbide (SiC) in the methyltrichlorosilane (MTS, CH<inf>3</inf>SiCl<inf>3</inf>)/H<inf>2</inf> system. The formation of SiC thin film is controlled by various process parameters, such as temperature and pressure. In this study, we propose a reaction mechanism of MTS decomposition to SiC growth on a substrate surface for CVD reactors in the CH<inf>3</inf>SiCl<inf>3</inf>(MTS)/H<inf>2</inf> system. The reaction mechanism has two gas-phase pyrolysis reactions and one SiC film formation reaction. However, we individually build and validate MTS decomposition and SiC growth models to reduce uncertainty. An in-house version of reactingFoam, a reactive flow solver within OpenFOAM v2006, was used as the simulation tool. Our model accurately reproduced MTS decomposition for T = 1100–1350 K and [H<inf>2</inf>]/[MTS] = 2.65–14 at p = 101,325 Pa. Then, the MTS decomposition model was coupled with the SiC growth model, and the coupled model was applied to the SiC deposition data. The model could reproduce multiple datasets through validation studies.

DOI： 10.1016/j.heliyon.2023.e15061

Lattice Boltzmann study on the effect of hierarchical pore structure on fluid flow and coke formation characteristics in open-cell foam for dry reforming of methane 査読有り Open Access

Lin, YX; Yang, C; Zhang, W; Machida, H; Norinaga, K

CHEMICAL ENGINEERING SCIENCE 268 巻 2023年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

Dry reforming of methane (DRM) is one of the feasible strategies for carbon capture and utilization. However, the DRM process has a high tendency toward carbon deposition, which is restricted to industrial applications. In order to further improve coke formation resistance, open-cell foam with hierarchical pore structure was investigated. An artificial algorithm was adopted to construct a hierarchical pore structure in open-cell foam. Based on a 3-D lattice Boltzmann model, this work explored the effect of two hierarchical pore structure parameters on the fluid flow and coke formation characteristics in open-cell foam, which are hierarchical pore volume ratio (V<inf>2</inf>/V<inf>1</inf>) and hierarchical pore size ratio (d<inf>2</inf>/d<inf>1</inf>). The results indicated that increasing V<inf>2</inf>/V<inf>1</inf> and d<inf>2</inf>/d<inf>1</inf> can significantly promote permeability. Under the restriction ofV<inf>2</inf>/V<inf>1</inf> = 4, from d<inf>2</inf>/d<inf>1</inf> = 1 to 4, the coke formation rate decreases by approximately 57.49 %. These findings provide a theoretical basis and technical guidance for designing and developing open-cell foam reactors.

DOI： 10.1016/j.ces.2022.118380

Estimation of effective thermal conductivity in open-cell foam with hierarchical pore structure using lattice Boltzmann method 査読有り

日本のガス化技術査読有り

野田玲治, 榎本啓士, 波岡知昭, 伏見千尋, 細貝聡, 則永行庸

日本エネルギー学会機関誌えねるみくす 102 巻 ( 1 ) 頁： 74 - 79 2023年1月

Lin, YX; Yang, C; Zhang, W; Fukumoto, K; Saito, Y; Machida, H; Norinaga, K

APPLIED THERMAL ENGINEERING 218 巻 2023年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Thermal Engineering

Effective thermal conductivity in open-cell foam with hierarchical pore structure was estimated using lattice Boltzmann method. A new structure algorithm was proposed to reconstruct hierarchical pore structure in open-cell foam. In order to elucidate the heat transfer characteristics in hierarchical pore structure, the effect of structure parameters, namely the hierarchical pore size ratio (d<inf>2</inf>/d<inf>1</inf>), the hierarchical pore volume ratio (V<inf>2</inf>/V<inf>1</inf>), and temperature on the effective thermal conductivity was investigated. These results indicated that hierarchical pore structure is unfavorable to the effective thermal conductivity in open-cell foam for the heat conduction process. At high temperatures (T<inf>ave</inf> = 450–1650 K), however, the effective thermal conductivity in hierarchical pore structure is higher than that in uniform pore structure considering heat radiation. Furthermore, for the heat conduction process, a correlation of the effective thermal conductivity related to open-cell foam with hierarchical pore structure was proposed and validated by available experimental data.

DOI： 10.1016/j.applthermaleng.2022.119314

Boosting in-situ hydrodeoxygenation of fatty acids over a fine and oxygen-vacancy-rich NiAl catalyst br 査読有り Open Access

Wang, JY; Ren, DZ; Zhang, NH; Lang, JY; Du, YY; He, WH; Norinaga, K; Huo, ZB

RENEWABLE ENERGY 202 巻頁： 952 - 960 2023年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Renewable Energy

Hydrodeoxygenation (HDO) of fatty acids into long-chain alkanes for aviation fuels with alcohol hydrogen donor at mild condition over Ni-based catalyst is a practicable subject. However, highly active sites design for Ni-based catalyst remains significant challenges. Herein, a fine NiAl particle catalyst with numerous oxygen vacancy sites was fabricated via hydrothermal and reduction treatment. Introduction of small amount of Al species into Ni catalyst not only reduces the Ni particle size exposing plenty of active sites, but also generates oxygen vacancies in AlO<inf>x</inf> and sets up charge transfer in Ni-AlO<inf>x</inf> interfaces, thus guarantees the excellent in-situ HDO activity of fatty acids using isopropanol as hydrogen donor. Density functional theory calculation results further reveal that Ni (111) modified by AlO<inf>x</inf> with oxygen vacancy improves the charge density in Ni-AlO<inf>x</inf> interface and enhances the adsorption of fatty acid, facilitating the hydrodeoxygenation process. Benefiting from these attributes, Ni–Al<inf>0.33</inf>O<inf>x</inf> presented superior catalytic activity and stability, which achieved 93.2% yield of n-heptadecane at 250 °C and was able to reuse at least 4 times. Therefore, the as-prepared Ni–Al<inf>0.33</inf>O<inf>x</inf> is a promising Ni-based catalyst for alkanes production via in-situ HDO of fatty acids at mild conditions.

DOI： 10.1016/j.renene.2022.11.095

Modeling and estimating kinetic parameters for CO2 methanation from fixed bed reactor experiments 査読有り

Tsuboi T., Yasuda S., Choi C., Zhang W., Machida H., Norinaga K., Yajima T., Kawajiri Y.

Journal of Advanced Manufacturing and Processing 5 巻 ( 1 ) 2023年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Advanced Manufacturing and Processing

CO<inf>2</inf> methanation, which converts CO<inf>2</inf> and hydrogen into methane as fuel, is one of the promising candidates for the development of CO<inf>2</inf> utilization technologies. Recently, a highly active catalyst made of Ni/ZrO<inf>2</inf> for methanation has been developed, and is currently investigated as a potential use in a high-performance reactor. However, design of reactor must be carried out carefully, since this reaction is highly exothermic, which may cause reactor runaway and deterioration of catalysts. For this problem, a mathematical model that can predict the behavior inside the reactor is necessary. In this work, we consider the methanation reaction of CO<inf>2</inf> in a reactor model and estimate the kinetic parameters in the reaction rate model from experimental data. In the parameter estimation using literature values and Tikhonov regularization, eight kinetic parameters in the rate equations were identified from 64 data points with a wide range of conditions. We confirm that molar fractions at the reactor exit predicted by this reactor model are in good agreement with the experimental results. Furthermore, the developed model was validated to predict the compositions and temperature that were not used in the estimation. We expect the developed model will be a powerful tool for the reactor design.

DOI： 10.1002/amp2.10145

Large-eddy simulation of the non-adiabatic reforming process of hot coke oven gas using a flamelet-based approach Open Access

New Data Processing Method for Heavy Oil Components Analyzed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry 査読有り Open Access

Katano, K; Suzuki, T; Matsumoto, K; Kato, H; Norinaga, K

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 66 巻 ( 4 ) 頁： 101 - 108 2023年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the Japan Petroleum Institute

A data processing method to automatically assign molecular formula and correct the abundances was developed and used to improve the reliability and quantitative accuracy of data obtained via Fourier transform ion cyclotron resonance mass spectrometry. The technique was applied to analyze fractions of atmospheric residue, and assigned molecular formula for each fraction. The algorithm automatically identified nearly 20,000 heavy oil components. The reliability of the data processing technique was demonstrated by absolute mean mass errors in the range of 0.15-0.23 ppm. Distillation simulation was used to correct the abundances of assigned molecular formula. The distillation properties were estimated from the molecular formula, and corrections made to match the simulated results within 1 wt.%. The correction factor demonstrated that lower boiling point components tended to require higher correction factors, suggesting that the ion transport efficiency of the instrument becomes lower in the lower molecular weight region.

DOI： 10.1627/jpi.66.101

Changes in Intermolecular Interaction Forces Inducing Glass Transition Determined by Three-Dimensional Aggregated Structural Models of Coal 査読有り Open Access

Hata, Y; Hayashizaki, H; Matsuzaki, Y; Morimoto, M; Takanohashi, T; Takahashi, T; Kanehashi, K; Norinaga, K

ISIJ INTERNATIONAL 63 巻 ( 9 ) 頁： 1433 - 1440 2023年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

The three-dimensional aggregated structural models of two types of coals, A and B, were constructed. It is found that the density and the T<inf>g</inf> of the models were qualitatively consistent with values obtained experimentally. The T<inf>g</inf> of coals A and B calculated using the model structures are 315°C and 328°C, respectively. The effect of temperature on the distribution of cohesive energy was quantitatively elucidated using the three-dimensional aggregated structural models. The cohesive energy density (CED) of coal B was greater than that of coal A at temperatures <T<inf>g</inf>. However, at temperatures >T<inf>g</inf>, the CED of coal A is comparable to that of coal B. This implies that the molecules are more strongly aggregated in coal B than in coal A at low temperatures due to hydrogen bonding, and the intermolecular interaction is considered to have gradually relaxed above the T<inf>g</inf>. It is concluded that differences in the molecular and cohesive structures of the coals led to differences in the distribution of van der Waals energy and electric energy at different temperatures. The van der Waals energy changed from attraction to repulsion at about 450°C and 285°C in coal A and B, respectively. Electric energy remained an attractive force as the temperature increased. The mechanism of the 13°C difference in the calculated T<inf>g</inf> of each coal can be explained by the temperature change in the intermolecular force distribution. Therefore, this three-dimensional aggregated structural model can be used to understand the thermal behavior of aggregated molecules, such as coal thermoplasticity.

DOI： 10.2355/isijinternational.ISIJINT-2022-547

Experimental Study on Quantitative Evaluation of Transferable Hydrogen in Possible Raw Materials for Metallurgical Cokes Including Bituminous, Sub-bituminous, Lignite Coals and Biomass 査読有り Open Access

Zhang, LJ; Uehara, Y; Nakamura, M; Choi, C; Liu, C; Machida, H; Hayashizaki, H; Kawai, Y; Hata, Y; Norinaga, K

ISIJ INTERNATIONAL 63 巻 ( 9 ) 頁： 1441 - 1450 2023年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

Researchers have thoroughly studied coal pyrolysis over a long period, while the analysis of volatile evolution and the chemical structural changes of solid char were carried out individually in most of the studies. In this work, we quantified the chemical reactions to explain the different physical phenomena, such as softening and caking properties, exhibited by different ranks of coals during pyrolysis. Four typical carbonaceous feedstocks (bituminous, sub-bituminous, lignite coals, and biomass) were selected as test samples. The authors analyzed the generated gas during pyrolysis by using a quadrupole mass spectrometer (Q-MS) and the chemical structure of the pyrolyzed char via spectroscopic methods (NMR, FT-IR, CHNS, and XPS) to gain new insights into the pyrolysis mechanism of the carbonaceous feedstocks. Transferable hydrogen was introduced to define the hydrogen used to stable the free radicals formed during pyrolysis, which can be obtained by quantifying the conversion routes of hydrogen. The hydrogen released for the growth of aromatic clusters has three pathways, namely, (1) consumption by the hydrodeoxygenation reaction to produce pyrolytic vapor, (2) release as gaseous H<inf>2</inf>, and (3) transferable hydrogen. The calculation shows that the amount of transferable hydrogen during pyrolysis decreases as the coal rank gets lower. For pyrolysis up to 500°C, the amount of transferable hydrogen is 3.96, 2.32, and 1.36 mol/kg-coal for bituminous, sub-bituminous, and lignite coals, respectively. On the other hand, the transferable hydrogen of biomass needs to be further considered in terms of the effect of cellulose and hemicellulose’s structure.

DOI： 10.2355/isijinternational.ISIJINT-2022-517

Yu, PL; Yadav, S; Hu, Y; Kai, R; Norinaga, K; Kurose, R; Watanabe, H

JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 18 巻 ( 2 ) 頁： 23-00279 - 23-00279 2023年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Thermal Science and Technology

Large-eddy simulation (LES) coupling with a non-adiabatic flamelet progress variable (NA-FPV) approach with reconstructed flamelet chemistry states is employed to simulate the hot coke oven gas (HCOG) reforming process. In the NA-FPV model, the chemistry states are first computed based on the correction factor for enthalpy defects and then modified by substituting the species statistics in the maximum heat loss state with those of less heat release to compensate for the unphysical results. The numerical results of LES coupling this NA-FPV model have been compared with the experimental measurement data in terms of temperature and yields, and reasonable agreements have been achieved. According to the LES results, it is seen O<inf>2</inf> only participates in the combustion process in the upper stream and the combustion process which mainly consumes H<inf>2</inf> and CO is to provide the other reforming process with heat and steam. In the upper and middle streams, the main HCOG jet is wrapped by the swirling high-temperature combustion products, and the reforming process primarily takes place by consuming CH<inf>4</inf>, polycyclic aromatic hydrocarbons (PAHs), and steam, while considerable H<inf>2</inf>, CO, and CO<inf>2</inf> are produced. It is observed that accompanying the reforming process C<inf>2</inf>H<inf>2</inf> is generated and it peaks in the middle stream, thus it is considered soot is formed in the complex reactions.

DOI： 10.1299/jtst.23-00279

Development of a kinetic model for CO2 methanation over a commercial Ni/SiO2 catalyst in a differential reactor 査読有り Open Access

Khuenpetch, A; Choi, C; Reubroycharoen, P; Norinaga, K

ENERGY REPORTS 8 巻頁： 224 - 233 2022年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy Reports

Development of a kinetic model for CO<inf>2</inf> methanation over a commercial nickel catalyst was performed to consider pathways of CO<inf>2</inf> conversion via Sabatier and RWGS reactions. H<inf>2</inf>/CO<inf>2</inf> ratio in the feed gas composition was varied at the stoichiometry of the Sabatier reaction assuming a fictitious CO<inf>2</inf> conversion of 0 to 0.7. Non-stochiometric gas feeding and the addition of product gases, i.e., methane and steam, were also considered to examine reaction orders and inhibition effects. The kinetic tests were carried out at 300–350 °C and 0.1–0.9 MPa. GHSV corresponded to 37,494 h−1. The stable activity was achieved by forcibly stressing the catalyst under the equilibria at 500 °C for 35 h. The kinetic measurements were conducted at an isothermal differential fixed bed reactor in the absence of heat and mass transport limitations. The methanation reaction was first fitted with the power law and LH approaches by considering the Sabatier reaction. Then, the RWGS reaction was added to consider CO formation using the power law models. The results showed a better fitting of experimental observations by using the LH expression with the formation of formyl as RDS and the power law model with inhibiting influence of water.

DOI： 10.1016/j.egyr.2022.10.194

1-07 インジウム/亜鉛を電析した銅フォーム電極触媒による高選択的二酸化炭素還元査読有り

シリソンブーンチャイスチャダ, 町田洋, 則永行庸

石炭科学会議発表論文集 59 巻 ( 0 ) 頁： 14 - 15 2022年10月

2-26 水素化と急速熱分解によるリグニンの化学原料への転換査読有り

ジャンリージュエン, シリソンブーンチャイスチャダ, 町田洋, 則永行庸

石炭科学会議発表論文集 59 巻 ( 0 ) 頁： 80 - 81 2022年10月

2-06 詳細な化学を考慮した噴流床石炭ガス炉における多環芳香族化合物やすす生成のシミュレーション査読有り

李泰霖, 崔哲溶, 福本一生, 町田洋, 則永行庸

石炭科学会議発表論文集 59 巻 ( 0 ) 頁： 40 - 41 2022年10月

Analysis of Low Temperature-oxidation Mechanism for Coal by Using High Resolution Solid State NMR and Gas Analysis 査読有り Open Access

Hata, Y; Takahashi, T; Sakuragi, K; Yamaguchi, A; Saito, K; Norinaga, K

TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN 108 巻 ( 10 ) 頁： 693 - 702 2022年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Tetsu to Hagane Journal of the Iron and Steel Institute of Japan

Spontaneous combustion property of low rank coal, an important issue in coal science, has been substantially studied. However, there are few studies discussing quantitative chemical structural changes of coal during its oxidization under 80°C. In the present study, low rank coals of X and Y were oxidized in an adiabatic vessel where their temperature was increased due to spontaneous heating. Generated gases of H<inf>2</inf>O, CO<inf>2</inf>, and CO were analyzed by gas chromatography during the oxidization. As a result, coal Y, which was more easily oxidized than coal X, showed higher generation rate of CO<inf>2</inf> and CO gas than coal X. Some of H<inf>2</inf>O generated during the oxidation must have been remained in coal as adsorbed water since the amount of water in the oxidized coal was higher than that before oxidation. 13C MAS NMR spectra of coal X and Y indicated that and chemical reaction producing carboxyl acid in coal Y is more activated than that in coal X. Furthermore, the number of aromatic carbon was reduced during the oxidization. It implied that the aromatic carbon might contribute to oxidization reaction. Coal Y before oxidation had smaller number of aromatic carbon per one cluster than coal X, while the structural parameters of aliphatic carbons in coal X and Y were almost the same. It is considered that smaller number of aromatic carbons more destabilize carbon radicals to generate “active” species. Such active carbon radicals are suggested to also react with oxygen in the atmosphere.

DOI： 10.2355/tetsutohagane.TETSU-2022-010

Pretreatment of lignin by electrochemical hydrogenation to enhance the olefins and aromatic products during rapid pyrolysis 査読有り Open Access

Zhang, LJ; Sirisomboonchai, S; Choi, C; Machida, H; Norinaga, K

JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 166 巻 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Analytical and Applied Pyrolysis

Lignin is one of the most promising biopolymers for producing hydrocarbons and aromatic compounds in nature. Electrochemical conversion of lignin is regarded as an attractive technology for producing various aromatic chemicals which are generally derived from fossil fuels. The author reports an electrochemical approach for hydrogenating alkaline lignin (AL), which uses relatively low-cost Ni foam as a working electrode under alkali electrolyte. The primary factors (such as power input, reactor type, temperature, reaction time, catalysts, and electrode substrates) of electrochemical hydrogenation were used to control the products' yield and features. The redox characteristics of the reaction system were directly compared with the cyclic voltammetry measurement under different parameters. After electrochemical hydrogenation (ECH), rapid pyrolysis was conducted on HAL samples to investigate the influence of electrochemical reactions on lignin. The maximum olefins and aromatics yield from HAL was increased to more than three times AL, accounting for 2.22 wt% and 4.07 wt%, respectively. Then, thermogravimetric analysis (TGA), elemental analysis (EA), Fourier-transform infrared spectroscopy (FTIR), and heteronuclear single quantum coherence (HSQC) NMR were employed to characterize hydrogenated lignin samples (HAL), as well as gas chromatography–mass spectrometry (GC-MS) was conducted to investigate the oil-phase products. This work focused on this electrochemical hydrogenation coupled with rapid pyrolysis process to give a possibility that converting lignin into not only liquid oil products, but solid hydrogenated lignin can be used to produce more olefins and aromatics in rapid pyrolysis, and presented the advantages and disadvantages of this two-stage process finally.

DOI： 10.1016/j.jaap.2022.105625

Efficient CO2 Electrochemical Reduction by a Robust Electrocatalyst Fabricated by Electrodeposition of Indium and Zinc over Copper Foam 査読有り

Sirisomboonchai, S; Machida, H; Tran, KVB; Kawasumi, M; Norinaga, K

ACS APPLIED ENERGY MATERIALS 5 巻 ( 8 ) 頁： 9846 - 9857 2022年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Energy Materials

Electrochemical reduction of CO<inf>2</inf>comprising the CO<inf>2</inf>reduction reactuib (CO<inf>2</inf>RR) and oxygen evolution reaction (OER) is one of the most promising technologies for electrification of the chemical process industry. Here, the performance of a electrocatalyst with a three-dimensional structure of InZnCu on Cu foam (CF) is presented. This electrocatalyst was fabricated by electrodeposition of In and Zn over Cu and exhibited a superior reduction of CO<inf>2</inf>to CO at a Faradaic efficiency of 93.7% at -0.7 V and an excellently long duration of 100 h. Due to the synergy of the thin In layer, the Zn nanosheets provided a high surface-active area and strong mechanical robustness during the reaction. Additionally, a two-electrode system was constructed based on the CF-modified surface, which provided valuable guidelines on the overall CO<inf>2</inf>RR-OER system for further evolution. Furthermore, due to the facile synthesis, the bimetal-layer double hydroxide (LDH) exhibited high conductivity and high OER performance. Hence, the two-electrode system assembled excellent electrocatalysts for the CO<inf>2</inf>RR-OER (InZnCu/CF||Cu(OH)<inf>2</inf>NWs@NiCo-LDH/CF) with high conversions of CO<inf>2</inf>to CO of 67% and 88% at 2 and 50 mA cm-2, respectively. Notably, the CO<inf>2</inf>RR-OER system exhibited excellent stability in a 40 h CO<inf>2</inf>conversion with a constant current density of 2 mA cm-2at an ultralow voltage of 1.59 V. Moreover, the calculation of the energy input converting CO per ton of CO<inf>2</inf>resulted in a low energy input range for further development in scalability. This overall CO<inf>2</inf>RR-OER proposes development in electrochemical CO<inf>2</inf>reduction for industrial applications.

DOI： 10.1021/acsaem.2c01564

Selective hydrogenation of furfural to tetrahydrofurfuryl alcohol in 2-butanol over an equimolar Ni-Cu-Al catalyst prepared by the co-precipitation method 査読有り Open Access

Rao, TU; Suchada, S; Choi, C; Machida, H; Huo, ZB; Norinaga, K

ENERGY CONVERSION AND MANAGEMENT 265 巻 2022年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy Conversion and Management

In order to upgrade biomass-derived platform chemicals to high value-added chemicals and liquid fuels, it is highly advantageous and desirable to synthesize suitable non-precious bimetallic catalysts that are efficient and versatile in chemical reactions. Equal moles of Ni and Cu were dispersed on varying mole ratios of Al by the co-precipitation method to synthesize Ni-Cu alloy particles to obtain a maximum yield of tetrahydrofurfuryl alcohol (THFA) by the liquid phase hydrogenation of furfural. The nickel species were active for both the furan ring (C=C) and carbonyl group (C=O) of furfural molecule, while Cu species were highly active for only the carbonyl group of furfural molecule. Systematic characterization of the prepared catalysts by XRD, TPR, STEM-EDS, and XPS analysis revealed the formation of highly active Ni-Cu alloys and near-equal Ni/Cu surface contents were achieved for the equimolar catalyst, which showcased a maximum of 98 mol% yield of THFA at 140 °C, 30 bar, 4 h. The reaction pressure and temperature showed a substantial effect on the product yield. The solvent selection also influenced the product selectivity, particularly with 2-butanol, which promoted the reaction with its hydrogen donor capacity and supported the ring hydrogenation of FAL to THFA. Moreover, the reduced Ni1Cu1-Al1 catalyst displayed good recyclability for three runs and an equal activity to that of a fresh catalyst after the regeneration.

DOI： 10.1016/j.enconman.2022.115736

【基調講演】石炭・重質油分野有機資源や二酸化炭素転換反応器における現象理解とシミュレーション査読有り

則永行庸

日本エネルギー学会大会講演要旨集 31 巻 ( 0 ) 頁： xviii - xix 2022年7月

CFD simulation of the Sabatier process in a shell-and-tube reactor under local thermal non-equilibrium conditions: Parameter sensitivity and reaction mechanism analysis 査読有り Open Access

Lin, YX; Zhang, W; Machida, H; Norinaga, K

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 47 巻 ( 34 ) 頁： 15254 - 15269 2022年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Hydrogen Energy

The Sabatier process is a competitive technology applied for carbon capture and utilization. This process increases the risk of carbon deposition and catalyst thermal degradation because of its exothermic property. In this study, a CFD model verified through existing experimental data was established to systematically investigate the Sabatier process in a shell-and-tube reactor. The effects arising from several operating parameters (e.g., gas flow rate, feed gas composition, the thermal conductivity of catalyst pellet, the inlet temperature of cooling phase, as well as phase change refrigeration) on temperature profile and reaction performance were studied. Moreover, a mechanism of three reactions was investigated, including CO<inf>2</inf> methanation, CO methanation, as well as RWGS reaction. Furthermore, the competition between CO<inf>2</inf> methanation and RWGS reaction was explored. According to the further sensitivity analysis, increasing the thermal conductivity of the catalyst particles would be effective to inhibit hot spots, while keeping the carbon conversion rate unchanged.

DOI： 10.1016/j.ijhydene.2022.03.029

Catalytic transfer hydrogenation of ethyl levulinate into γ-valerolactone over air-stable skeletal cobalt catalyst 査読有り

Ren, DZ; Zhao, C; Zhang, NH; Norinaga, K; Zeng, X; Huo, ZB

JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 10 巻 ( 2 ) 2022年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Environmental Chemical Engineering

A fast and easy handled batch air diffusion method (BA) was developed to obtain a non-pyrophoric, air-stable skeletal Co catalyst (A-SCo) for catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) into γ-valerolactone (GVL). A batch air diffusion method (BA) consumed the active adsorbed H<inf>2</inf> on the surface of skeletal Co (SCo) but maintained structure catalyst and avoided excessive oxidation of metallic Co, Ni and Al. The 96% yield of GVL was obtained over the A-SCo and HZSM-5 at 140 °C. Further study of CTH process shows that metallic state of A-SCo provides important active sites for dehydrogenation of i-PrOH, which is critical step for hydrogenation of EL. This study provides a simple, efficient method to prepare an air-stable skeletal metal catalyst for CTH and hydrogenation process.

DOI： 10.1016/j.jece.2022.107188

A review of thermal catalytic and electrochemical hydrogenation approaches for converting biomass-derived compounds to high-value chemicals and fuels 査読有り Open Access

Zhang, LJ; Rao, TU; Wang, JY; Ren, DZ; Sirisommboonchai, S; Choi, C; Machida, H; Huo, ZB; Norinaga, K

FUEL PROCESSING TECHNOLOGY 226 巻 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel Processing Technology

Major global issues such as greenhouse gas emissions and the excessive use of fossil fuels lead to looking for sustainable and clean energy resources. Lignocellulosic biomass is a prospective resource for sustainable carbon-based energy. The production of petroleum-based green fuels, chemicals, and solvents from biomass-derived products has garnered much attention in the recent past. The study of biomass derivatives hydrogenation improves the efficiency of generating high-value chemicals and provides much-needed insights into the primary reaction mechanism for the effective utilization of raw constituents or biomass. However, the existing thermochemical conversions of biomass and biomass-derived products such as thermal catalytic hydrogenation (TCH) involve energy-intensive and expensive processes. In this regard, sustainable energy generation attracts alternative conversion technologies, including electrochemical conversion (ECC), electrocatalytic hydrogenation (ECH), and photocatalytic conversions that can be directly integrated with renewable wind/solar technologies and operated at ambient or lower temperatures. The role of electrocatalyst and electrolyte is pivotal to achieve efficient and selective ECH of biomass organics. This review paper summarizes the utilization of TCH and ECH processes on cellulose/hemicellulose, lignin, and their derivatives/model compounds, including catalyst types, reaction conditions, hydrogenation efficiency, and technical limitations. The advantages and disadvantages of the two technologies for biomass utilization have also been compared, which provides a more favourable knowledge base and theoretical basis for the subsequent research work.

DOI： 10.1016/j.fuproc.2021.107097

Durability and fire-hazardous-risk evaluation of unique phase separation solvent using high-boiling-point amine and ether 査読有り

Maeda, N; Kishimoto, A; Machida, H; Yamaguchi, T; Yanase, K; Norinaga, K

INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL 114 巻 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Greenhouse Gas Control

Durability and fire hazard risk evaluations were conducted to determine the process feasibility of a unique phase separation solvent with a low regeneration temperature (90 °C) consisting of an amine, ether, and a small amount of water. The results are as follows. I) The amine degradation rate of the phase separation solvent was determined to be less than 1/10 of that of monoethanolamine, which was attributed to the high oxidative resistance and low regeneration temperature of the former. II) The composition of the gas that formed in the absorber was completely out of the combustible range during the treatment of 6% oxygen-containing gas on a dry basis. Therefore, we believe that this phase separation solvent is applicable to the treatment of exhaust gas from coal-fired thermal power plants and can realize stable operation with a small amount of amine required for replenishment.

DOI： 10.1016/j.ijggc.2021.103532

Fluctuation in diethylene glycol diethyl ether/water mixtures near the lower critical solution temperature studied by small- and wide-angle x-ray scattering and thermodynamic calculation 査読有り Open Access

Yanase, K; Tran, KVB; Yamaguchi, T; Machida, H; Norinaga, K

JOURNAL OF MOLECULAR LIQUIDS 346 巻 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Molecular Liquids

We studied local structure of diethylene glycol diethyl ether (DEGDEE)-water mixtures near the lower critical solution temperature (LCST) by means of simultaneous small- and wide-angle x-ray scattering measurement and thermodynamic calculation based on the activity coefficient model. Long-wavelength limits of structure factors S<inf>NN</inf>(0), S<inf>CC</inf>(0), and S<inf>NC</inf>(0), which respectively represent mean square fluctuations in the particle number, the concentration, and their cross correlation, are determined from scattering intensity extrapolated to the zero scattering vector and thermodynamic quantities according to the Bhatia and Thornton formula. S<inf>NN</inf>(0) and S<inf>CC</inf>(0) exhibit maxima near critical concentration. We found that difference between partial molar volumes of water and DEGDEE essentially results in S<inf>NN</inf>(0) values being one order of magnitude larger than S<inf>CC</inf>(0) values. Further, we determined Kirkwood-Buff (KB) integrals to clarify a mixing state of the solution from a mesoscopic point of view. The KB integrals also exhibit extrema near critical concentration. These results demonstrate self-segregations of both DEGDEE and water in a nanometer length scale even at homogeneous solution states, which can be regarded as a precursor of the macroscopic phase separation. Concentration dependence of the wide-angle scattering curve suggests that the short-range structure, whose length scale is sub-nanometer, moderately changes between the intrinsic bulk structures of DEGDEE and water. Comparison of the KB integrals with those determined by the activity coefficient model using non-random two-liquid equation is presented and effects of the fluctuation on the phase behavior are discussed.

DOI： 10.1016/j.molliq.2021.117830

Determination of Kinetic Parameters for CO2 Methanation (Sabatier Reaction) over Ni/ZrO2 at a Stoichiometric Feed-Gas Composition under Elevated Pressure 査読有り

Modeling the Chemical Structures of Coals with Different Classifications Using Mean Molecular Weights 査読有り Open Access

Hata, Y; Hayashizaki, H; Takanohashi, T; Takahashi, T; Kanehashi, K; Norinaga, K

ISIJ INTERNATIONAL 62 巻 ( 5 ) 頁： 948 - 956 2022年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

The chemical structure models for the extractions and residues of two types of bituminous coals, A and B, were constructed. The molecular weights of the extractions were determined via gel permeation chromatography (GPC). New standard materials with structures similar to those of coal extraction (i.e., 9, 10- diphenylanthracene, 5,6,11,12-tetraphenylnaphthracene, and chemical compounds A (Mw = 811) and B (Mw = 1 135), which were synthesized using the coupling reaction) were adopted for GPC in order to obtain more accurate mean molecular weights than those in literature. Furthermore, a support program for constructing chemical structure models based on 1H nuclear magnetic resonance (NMR) spectra was adopted. The coal models constructed suitably indicate the differences between the types of coal. In particular, it is found that a high pyridine-insoluble fraction extracted rate, which accounts for the most significant difference between the total extracted rates for coals A and B, enhance the coking property of coal A. In addition, the cluster size in the magic solvent-insoluble fraction might affect the softening property of coal.

DOI： 10.2355/isijinternational.ISIJINT-2021-459

Choi, C; Khuenpetch, A; Zhang, W; Yasuda, S; Lin, YX; Machida, H; Takano, H; Izumiya, K; Kawajiri, Y; Norinaga, K

ENERGY & FUELS 35 巻 ( 24 ) 頁： 20216 - 20223 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

Methanation of CO<inf>2</inf> using H<inf>2</inf> obtained by renewable energy sources has been gaining attention as one of the promising options for utilizing captured CO<inf>2</inf> and surplus power obtained when intermittent power sources such as solar and wind energy are used. Herein, kinetics of CO<inf>2</inf> methanation over Ni/ZrO<inf>2</inf> was studied using a tubular quartz reactor at 0.9 MPa. The Sabatier reaction (CO<inf>2</inf> + 4H<inf>2</inf> = CH<inf>4</inf> + 2H<inf>2</inf>O, ΔH<inf>r</inf>298K = – 165 kJ mol–1) was carried out under stoichiometric gas feeding (CO<inf>2</inf>/H<inf>2</inf> = 1/4 v/v to CH<inf>4</inf>/H<inf>2</inf>O = 1/2 v/v), and its reaction rate was determined. The exothermic nature of CO<inf>2</inf> methanation and extremely high catalytic activities increased the reaction temperature to 400–600 °C even when the feed-gas temperature was as low as 250–400 °C, and the gas hourly space velocity was as high as 3 × 106 h–1. Nonlinear regression analyses based on one- and multistep kinetic models were used to investigate the reaction rates to estimate the kinetic parameters. Both models with optimized parameters can reproduce the experimentally obtained CH<inf>4</inf> formation rates for the entire range of the feed-gas conversion with a coefficient of determination (R2) of over 0.98.

DOI： 10.1021/acs.energyfuels.1c01534

An Alternative CO2 Capture with a Pressure Swing Amine Process Driven by Cryogenic Pumping with the Unused Cold Energy of Liquefied Natural Gas 査読有り

Machida, H; Hashiride, R; Niinomi, R; Yanase, K; Hirayama, M; Umeda, Y; Norinaga, K

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 9 巻 ( 47 ) 頁： 15908 - 15914 2021年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Sustainable Chemistry and Engineering

This paper presents an alternative concept of CO2 capture that can substantially reduce the energy required for CO2 capture by utilizing unused cold energy. The heat of vaporization of liquefied natural gas (LNG), of which the boiling point is 110 K, is a possible candidate for unused cold energy. This technology is based on a pressure swing amine process combined with a sublimation tank to cool CO2 released from a desorber into dry ice by exchanging the LNG cold energy. The feature of this technology is that pure CO2 is recovered mostly by a pressure swing that decreases the pressure in the desorber utilizing a cryogenic pump with CO2 sublimation instead of a mechanical pump. We developed an amine-based absorbent that can realize the proposed process for exhaust gas from a fossil fuel-fired power plant. A process simulation indicated that the required energy is as low as 0.25 GJ/ton CO2 when both the absorber and the desorber are operated at around 313 K, the desorber pressure is reduced to 1 kPa, and the sublimation tank is operated at 150 K.

DOI： 10.1021/acssuschemeng.1c05892

The effects of nitrogen functional groups and narrow micropore sizes on CO2 adsorption onto N-doped biomass-based porous carbon under different pressure 査読有り

Luo, JY; Liu, BG; Shi, R; Guo, Y; Feng, QG; Liu, Z; Li, LQ; Norinaga, K

MICROPOROUS AND MESOPOROUS MATERIALS 327 巻 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Microporous and Mesoporous Materials

The biomass-derived N-doped porous carbons have been proved promising adsorbent material, due to their good CO<inf>2</inf>/N<inf>2</inf> selectivity and excellent CO<inf>2</inf> adsorption performance. However, many researchers simply studied the effect of nitrogen groups or narrow micropores (less than 0.7 nm) on CO<inf>2</inf> uptake at 1 bar and ignored the role of different pressures. In this study, a promising porous carbon derived from eucalyptus bark with high CO<inf>2</inf> adsorption capacity was prepared by urea-assisted hydrothermal and KOH activation. The obtained porous carbons were found to be mainly microporous and showed rich nitrogen content. Among the materials, at 1 bar, NPC700 exhibits high CO<inf>2</inf> adsorption of 4.20 mmol/g and 6.98 mmol/g at 25 °C and 0 °C, respectively. Based on Grand canonical Monte Carlo (GCMC) simulation, the adsorption density and adsorption energy on graphite slit pore with different pore sizes (0.6–2.0 nm) and N-doped functional groups (pyridinic-N, pyrrole-N and graphitic-N) were calculated. And the results showed that the nitrogen functional groups played a crucial contribution on CO<inf>2</inf> adsorption capacity at relative low pressure (0–0.16 bar). In the case of relative high pressure (0.16–1 bar), the narrow micropores volume determined the CO<inf>2</inf> uptake capacity.

DOI： 10.1016/j.micromeso.2021.111404

Inhibition of temperature runaway phenomenon in the Sabatier process using bed dilution structure: LBM-DEM simulation 査読有り

Lin, YX; Yang, C; Choi, C; Zhang, W; Fukumoto, K; Machida, H; Norinaga, K

AICHE JOURNAL 67 巻 ( 10 ) 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Aiche Journal

The Sabatier process is promising for carbon dioxide utilization and energy storage. However, the serious problem that limits more comprehensive industrial applications is catalyst deactivation due to the temperature runaway phenomenon. The inert particle dilution approach, including the mixing dilution method and layered dilution method is applied to solve this problem. Based on the lattice kinetic scheme-lattice Boltzmann method (LKS-LBM), the effects of three parameters in bed dilution structure reconstructed by the discrete element method (DEM) on temperature distribution and carbon conversion rate were discussed, so as to investigate the relationship between packing structure and temperature distribution. Furthermore, numerical results indicated that an optimal bed dilution structure, which not only can control the peak temperature below the critical temperature to avoid coking and sintering of catalyst, but also can improve the conversion rate by almost 18% compared with the structure without dilution under the same circumstance.

DOI： 10.1002/aic.17304

Comprehensive Compositional Analysis of Heavy Oil Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and a New Data Analysis Protocol 査読有り

Katano, K; Teratani, S; Suzuki, T; Tanaka, R; Kato, H; Norinaga, K

ENERGY & FUELS 35 巻 ( 17 ) 頁： 13687 - 13699 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

A sequential method that deterministically estimates the molecular composition of heavy oil is reported. A sample of vacuum residua is preseparated into seven fractions: saturated (Sa), aromatic fractions containing one, two, and three or more rings (1A, 2A, and 3A+, respectively), polar and polyaromatic (Po and PA, respectively) resins, and asphaltene (As). The analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) uses one of three different ionization methods depending on the type of structure. Paraffinic species in Sa are ionized by Ag cationization and laser desorption. Aromatic species in 1A, 2A, 3A+, and Po are ionized by atmospheric pressure photoionization. Poorly volatile and condensed aromatic species in PA and As are ionized by laser desorption ionization. Collision-induced dissociation (CID) is used by the FT-ICR MS instrument to determine the structural building blocks. A new data analysis protocol developed to represent petroleum molecules named the composition and structure analyzer (CSA) requires data obtained before and after CID as inputs. The CSA provides juxtaposed attributes for chemical-structure description (JACDs). Structural information based on JACDs can be used to predict physical and chemical properties such as boiling and melting points and solubility parameters and build attribute-based reaction models, to optimize heavy oil upgrading processes.

DOI： 10.1021/acs.energyfuels.1c01429

Density and Viscosity Calculation of a Quaternary System of Amine Absorbents before and after Carbon Dioxide Absorption 査読有り

Tran, KVB; Sato, M; Yanase, K; Yamaguchi, T; Machida, H; Norinaga, K

JOURNAL OF CHEMICAL AND ENGINEERING DATA 66 巻 ( 8 ) 頁： 3057 - 3071 2021年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Chemical and Engineering Data

Viscosity and density of amine absorbents affect directly their flow, which is involved in the process design and simulation of carbon dioxide capture. A mixture of 2-(ethyl amino) ethanol (EAE), diethylene glycol diethyl ether (DEGDEE), and water changes its phase from homogeneous to two-liquid ones on CO2 absorption. It is difficult to calculate the viscosity and density of this phase separation solution, especially those of quaternary-component phases. In this research, models to calculate the density and viscosity of the quaternary-component system of EAE/DEGDEE/water/carbamate were suggested based on nonrandom two-liquid (NRTL)-DVOL and NRTL-DVIS models. Given the component concentrations, these models can replicate well the viscosity and density of the solutions. A good calculation result with a few numbers of parameters makes the models simple and easy to use.

DOI： 10.1021/acs.jced.1c00195

Production of light hydrocarbons from organosolv lignin through catalytic hydrogenation and subsequent fast pyrolysis 査読有り Open Access

Zhang, LJ; Choi, C; Machida, H; Norinaga, K

JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 156 巻 2021年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Analytical and Applied Pyrolysis

Valorization and utilization of lignin have been drawing increasing attention recently. Hydroprocess is one of the main technologies, which can reduce organic compounds and partially depolymerize the macromolecular structure of lignin. The mechanism of lignin hydroprocess has been extensively discussed focusing on hydrogenolysis. In contrast, the solid residue regarded as unreacted or depolymerized lignin has drawn less attention so far. This study proposes an integrated process that consists of catalytic hydrogenation and subsequent fast pyrolysis for valorizing lignin. The results showed that 48−87 wt.% of solid product could be recovered as hydrogenated lignin (H-EOL) after hydrogenation at 200–250 ℃ for 1−7 h. Chemical structure of H-EOL was comprehensively investigated by means of elemental analysis, FTIR, 13C & 1H NMR, and TGA. Furthermore, behavior of fast pyrolysis of H-EOL was detected here for the first time. H-EOL has higher hydrogen to carbon atomic effective ratio(H/C<inf>eff</inf> ratio) and achieves the increasing reactivity of thermal decomposition. H-EOL yields light olefins double as much as raw ethanol organosolv lignin (EOL). And the formation of alkanes (C<inf>1</inf>-C<inf>4</inf>), benzene, and toluene was promoted to various degrees, while the yield of carbon monoxide, carbon dioxide, and vapor decreased. A novel and efficient pretreatment method has been provided to valorize lignin, which is instructive for subsequent research.

DOI： 10.1016/j.jaap.2021.105096

An Approach to Simulate Vapor Phase Reactions of Coal Volatiles in a Reducing Section of the Two Stage Entrained Flow Gasifier with a Detailed Chemical Kinetic Model

Choi, C; Adachi, N; Zhang, W; Machida, H; Hayashi, J; Watanabe, H; Norinaga, K

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 54 巻 ( 6 ) 頁： 334 - 343 2021年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Chemical Engineering of Japan

An approach in predicting reactions undergone by coal volatiles in a reducing section (reductor) of an air-blown two-stage entrained flow gasifier toward designing a better gasification process was proposed. A detailed chemical kinetic model was applied to simulate chemical reactions of a complex molecular mixture of the coal volatiles evolved due to rapid pyrolysis of coal fed into the reductor. The composition of volatiles was determined based on pyrolysis-gas chromatography experiments, where 22 compounds, including inorganic gases (H<inf>2</inf>, H<inf>2</inf>O, CO and CO<inf>2</inf>), light hydrocarbon gases (C1–C4), and aromatic hydrocarbons (benzene to pyrene) were identified. Gas composition at the reductor inlet was estimated by integrating the information on the experimentally obtained molecular composition of the volatiles, and the thermodynamically calculated composition of inorganic gases generated from the combustor and the coal feeding rates into reductor and combustor. Concentration profiles of the individual chemical species, as well as soot particles together with the flow direction of the reductor, were revealed using an extended detailed chemical kinetic model involving 202 species, 1351 gas-phase reactions, and 101 surface reactions for soot formation and growth. The simulation revealed that near-complete decomposition of tar regarded as a set of all aromatic hydrocarbons is likely to require operation temperature of the reductor at temperatures as high as 1200°C, when the combustor is operated at 1800°C.

DOI： 10.1252/jcej.20we171

A Review on Detailed Kinetic Modeling and Computational Fluid Dynamics of Thermochemical Processes of Solid Fuels 査読有り

Choi, C; Zhang, W; Fukumoto, K; Machida, H; Norinaga, K

ENERGY & FUELS 35 巻 ( 7 ) 頁： 5479 - 5494 2021年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

This review presents the recent advances in computational approaches to understand thermochemical reactions of solid fuels with minimized empirical factors. It includes studies on kinetic modeling of gas-phase reactions of multicomponent molecular mixtures of volatiles derived from primary pyrolysis of solid fuels using a database for elementary reactions. Mechanistic studies to model the devolatilization of biomass and coal upon heating are also mentioned. The efforts to integrate the kinetic model with computational fluid dynamics to understand the flow and heat transfer behavior of industrial reactors for solid fuel conversions, including gasification and combustion, are reviewed. These advances are primarily based on the conventional forward analysis that provides a deeper understanding of chemically reacting flows of fuels undergoing thermochemical reactions. For the further development of the thermochemical conversion technology, it can be expected to develop alternative approaches such as inverse analysis to determine the optimal reactor design and operating conditions.

DOI： 10.1021/acs.energyfuels.0c04052

Catalytic hydrotreatment of alkaline lignin and its consequent influences on fast pyrolysis 査読有り Open Access

Zhang, LJ; Choi, C; Machida, H; Huo, ZB; Norinaga, K

CARBON RESOURCES CONVERSION 4 巻頁： 219 - 229 2021年

担当区分：最終著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

The current state of lignin has been characterized by these three: (1) as one of the main components in lignocellulosic biomass with an abundant amount; (2) not be taken seriously but treated as a waste product; (3) underutilized due to a complex and stubborn structure. However, lignin can be a rich source for hydrocarbons and aromatic compounds when gives appropriate utilization. In this work, we have studied the hydrotreatment of alkaline lignin (AL) under relatively mild conditions and further investigated the characterization of hydrogenated lignin (HL), especially the behavior during fast pyrolysis. The recovery of the HL decreased with increasing reaction temperature from 60 wt.% to 41 wt.% in the range of 150–250 ℃. The hydrotreated products were analyzed using Elemental Analysis, FTIR (for HL) and GC–MS (for bio-oil). The HL samples were found to have a higher hydrogen/carbon atomic effective ratio (H/C<inf>eff</inf> ratio) and a higher degree of saturation than AL. Compared to the internal structure of the lignin before and after hydrotreatment, the side chain groups were removed from AL during the process. After that, from the fast pyrolysis of HL, it was observed that more light hydrocarbons and aromatic compounds were formed than that of AL. Furthermore, fast pyrolysis in the hydrogen atmosphere revealed that more volatile fractions were released compared to the Helium atmosphere. The total olefins yield was increased for HL compared AL from 1.02 wt.% to 3.1 wt.% at 250 ℃ for 7 hours. This study of HL is instructive to some extent for the industrial utilization of lignin.

DOI： 10.1016/j.crcon.2021.09.001

A comprehensive study on butanolysis of furfuryl alcohol to butyl levulinate using tungstated zirconia and sulfonated carbon catalysts 査読有り Open Access

Thuppati, UR; Choi, C; Machida, H; Norinaga, K

CARBON RESOURCES CONVERSION 4 巻頁： 111 - 121 2021年

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

This work presents the formation of butyl levulinate, a potential fuel additive, and an excellent renewable chemical obtained by the butanolysis of furfuryl alcohol (FAL) over a solid acid catalyst. The butanolysis of furfuryl alcohol reaction is a strong function of acidity for which tungstated zirconia (WO<inf>3</inf>-ZrO<inf>2</inf>), a robust solid acid catalyst, and a sulfonated carbon catalyst were employed to produce high yields of butyl levulinate targeting a lower initial molar ratio of butanol to FAL. A maximum of 28 mol% yield of butyl levulinate was obtained with tungstated zirconia catalyst. Easily prepared sulfonated carbon catalyst at high reaction temperatures facilitated the complete conversion of reaction intermediate, 2-butoxymethylfuran (2-BMF) through which butyl levulinate was formed, and as high as 80 mol% of butyl levulinate yield was produced at an initial mole ratio of 8.5:1 of butanol to FAL. The better results of sulfonated carbon catalyst could be attributed to the presence of -SO<inf>3</inf>H, carboxylic acid, and phenolic OH groups on the carbon surface.

DOI： 10.1016/j.crcon.2021.03.003

Durability and fire-hazardous-risk evaluation of unique phase separation solvent using high-boiling amine and ether 査読有り

Maeda N., Kishimoto A., Machida H., Yamaguchi T., Yanase K., Norinaga K.

15th Greenhouse Gas Control Technologies Conference 2021 Ghgt 2021 2021年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：15th Greenhouse Gas Control Technologies Conference 2021 Ghgt 2021

Durability and fire hazard risk evaluation were conducted to determine the process feasibility on the unique phase separation solvent with low regeneration temperature (90 °C), consisting of amine, ether, and small amount of water. The results we obtained are as follows; I) The amine degradation rate of the phase separation solvent would be less than 1/10 of that of monoethanolamine (MEA), which was contributed by its high oxidative resistant nature and low regeneration temperature. II) The gas composition formed in the absorber was completely out of combustible range and almost no accumulations of explosive compounds such as peroxides were observed when in contact with 6 % oxygen containing gas (dry base). Therefore, we believe that the phase separation solvent is applicable to the treatment of exhaust gas from coal-fired thermal power plants.

Energy analysis of CO2 separation process with low energy consumption using phase separation solvent 査読有り

Maeda N., Nakanishi K., Kishimoto A., Machida H., Yamaguchi T., Norinaga K.

15th Greenhouse Gas Control Technologies Conference 2021 Ghgt 2021 2021年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：15th Greenhouse Gas Control Technologies Conference 2021 Ghgt 2021

We calculated the energy required for regeneration when the phase separation solvent solvent is applied to the treatment of exhaust gas from coal-fired power plants. This solvent is characterized by regeneration at a low temperature of less than 100°C. As a result, it was clarified that under ideal conditions with no pressure drop and no heat loss, the required energy could be suppressed to 1.5 GJ/ton-CO2 by satisfying the following conditions; i) pinch point of the heat exchanger between rich-amine and lean-amine: 1 °C, ii) water concentration of the solvent: kept at 10 wt%, iii) COP of the heat pump: 5.5. However, increase of the pinch point, increase of the water concentration, and decrease of the COP will all result in a significant increase in the required energy. Therefore, in order to realize a process with low energy consumption, it is essential to meet these design constraints.

2-14 触媒層温度及びガス組成分布を考慮した解析によるメタネーション反応速度モデルの検討査読有り

安田将也, 町田洋, 則永行庸

石炭科学会議発表論文集 57 巻 ( 0 ) 頁： 44 - 45 2020年10月

2-16 CO2分離回収の省エネルギー化に向けた相分離吸収剤およびH2ストリッピングプロセスの開発査読有り

町田洋, 走出龍星, 鈴木健弘, 西尾仁志, 柳瀬慶一, チャンクウィン, 則永行庸

石炭科学会議発表論文集 57 巻 ( 0 ) 頁： 48 - 49 2020年10月

Online composition analysis of phase separation solvent for carbon dioxide capture using ATR-FT-IR 査読有り

Sato M., Tran K.V.B., Yamaguchi T., Machida H., Norinaga K.

Journal of Advanced Manufacturing and Processing 2 巻 ( 4 ) 2020年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Advanced Manufacturing and Processing

An amine solvent that undergoes phase change after absorption of CO<inf>2</inf> has been studied to reduce the energy consumed during the CO<inf>2</inf> capture process. Depending on the components of the solvent, the CO<inf>2</inf>-rich phase can be separated for the regeneration step or the component in CO<inf>2</inf>-lean phase accelerates the regeneration step in the solvent that undergoes liquid-liquid phase change. Since the homogeneous solvent separates into two liquid phases after CO<inf>2</inf> absorption, an analysis method to track the change in chemical species during the absorption process, especially at the phase separation time, is necessary to illuminate the phenomenon. To establish an online method to analyze the components of the solvent, a Fourier-transform infrared (FT-IR) spectrometer equipped with an attenuated total reflection (ATR) probe was used during the CO<inf>2</inf> absorption of phase separation solvent composed of amine, ether, and water. The calibration samples of amines, ethers, and CO<inf>2</inf>-loaded solutions were used to develop the partial least square regression model. The consumption of reactants, as well as the formation of products, can be monitored quantitatively using the FT-IR spectra. Utilizing this information, the changes in the chemical species shed light on the phase separation mechanism of this solvent: ether was pushed out of the solvent to form a CO<inf>2</inf>-lean phase due to its hydrophobicity, while CO<inf>2</inf> and its products along with amine and water remain in the CO<inf>2</inf>-rich phase. Without sampling, this rapid and high-accuracy method is suitable for closed processes, especially for a high-pressure process.

DOI： 10.1002/amp2.10067

Rate of CO2 absorption of a phase-separation absorbent 査読有り

Esaki T., Machida H., Norinaga K.

Journal of Advanced Manufacturing and Processing 2 巻 ( 1 ) 2020年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Advanced Manufacturing and Processing

In this study, we evaluated the CO<inf>2</inf> absorption characteristics of a phase-separation amine absorbent. The phase-separation absorbent consists of a 30:60:10 (by weight percent) mixture of 2-(ethylamino)ethanol, diethylene glycol diethyl ether, and water. The CO<inf>2</inf> absorption rate of the phase-separation absorbent was measured in a lab-scale counter flow absorber. In addition, the CO<inf>2</inf> transport phenomena in the absorber were analyzed by performing model fitting. The experimental results revealed that the CO<inf>2</inf> absorption rates are different before and after phase separation. In fact, the overall CO<inf>2</inf> absorption capacity coefficient after phase separation is 4.5 times higher than that obtained before phase separation. By changing the gas-liquid ratio, we obtained a CO<inf>2</inf> recovery ratio of over 80% using the model. Thus, the absorption temperature, CO<inf>2</inf> loading, and gas-liquid ratio can be tuned to obtain the desired CO<inf>2</inf> recovery ratio.

DOI： 10.1002/amp2.10033

CO2 Gasification of Sugar Cane Bagasse: Quantitative Understanding of Kinetics and Catalytic Roles of Inherent Metallic Species 査読有り

1-12 CO2メタネーション反応器における伝熱と流動に関する数値解析査読有り

溝口莉彩, 町田洋, 則永行庸

石炭科学会議発表論文集 56 巻 ( 0 ) 頁： 24 - 25 2019年10月

2-5 詳細反応化学速度モデルを用いた噴流床石炭ガス化炉における芳香族炭化水素の改質およびスス生成シミュレーション査読有り

安達希美, 町田洋, 則永行庸

石炭科学会議発表論文集 56 巻 ( 0 ) 頁： 56 - 57 2019年10月

1-22 石炭熱分解時の芳香族クラスター成長により発生する水素の転換反応機構査読有り

福岡鉄也, 町田洋, 則永行庸

石炭科学会議発表論文集 56 巻 ( 0 ) 頁： 44 - 45 2019年10月

1-13 相分離型省エネルギーCO2吸収剤のCO2吸収再生性能評価査読有り

鈴木健弘, 西尾仁志, 柳瀬慶一, 町田洋, 則永行庸

石炭科学会議発表論文集 56 巻 ( 0 ) 頁： 26 - 27 2019年10月

1-2-2 石炭ガス化炉内硫黄化合物転換特性の詳細化学反応速度モデルに基づく解析査読有り

安達希美, 町田洋, 則永行庸

日本エネルギー学会大会講演要旨集 28 巻 ( 0 ) 頁： 10 - 11 2019年7月

2-1-2 触媒固定床反応器による実験に基づくCO2メタン化反応速度モデルの構築査読有り

安田将也, 町田洋, 則永行庸, 高野裕之, 泉屋宏一

日本エネルギー学会大会講演要旨集 28 巻 ( 0 ) 頁： 32 - 33 2019年7月

Continuous monitoring of char surface activity toward benzene 査読有り Open Access

Choi C., Shima K., Kudo S., Norinaga K., Gao X., Hayashi J.i.

Carbon Resources Conversion 2 巻 ( 1 ) 頁： 43 - 50 2019年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

Kinetics of thermal decomposition of benzene on lignite-derived char was investigated at 900 °C by applying a new method to continuously monitor the char surface activity. Benzene vapor was continuously forced to pass through a micro fixed bed of char with residence time as short as 7.6 ms, and then detected continuously by a flame-ionization detector. Results showed the presence of two different types of char surfaces; consumptive Type I surface and non-consumptive (sustainable) Type II surface. Type I surface of a partially CO<inf>2</inf>-gasified char had an capacity of carbon deposit from benzene over 20 wt%-char and an initial activity (represented by a first-order rate constant) as high as 160 s−1. Both of them decreased with increasing carbon deposit due to consumption of micropores accessible to benzene, and finally became zero leaving Type II surface that had a very stable activity with rate constant of 4 s−1. The chars without gasification had capacities of Type I surfaces smaller by two orders of magnitude than the partially gasified char, while the Type II surfaces had activities similar to that of the partially gasified char. It was found that Type II surface converted benzene into not only carbon deposit but also diaromatics and even greater aromatics. Composition of the greater aromatics was unknown because they were deposited onto the reactor wall immediately after passing through the char bed.

DOI： 10.1016/j.crcon.2018.12.001

Effect of SiO2 on loss of catalysis of inherent metallic species in CO2 gasification of coke from lignite 査読有り Open Access

Choi C., Ashik U.P.M., Kudo S., Uebo K., Norinaga K., Hayashi J.i.

Carbon Resources Conversion 2 巻 ( 1 ) 頁： 13 - 22 2019年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Carbon Resources Conversion

Inherent metallic species retained by coal char or coke, such as Na and Ca, behave as catalysts in gasification. The char/coke normally contains inherent SiO<inf>2</inf>, which can react with the inherent catalysts to form silicates, resulting in catalyst deactivation over the range of pyrolysis, carbonization and gasification, and thereby reducing the char/coke reactivity. The present authors simulated the inherent catalyst deactivation experimentally by blending a Victorian lignite with SiO<inf>2</inf>, briquetting the SiO<inf>2</inf>/lignite blend, carbonizing the briquette, and then gasifying the coke with CO<inf>2</inf>. The kinetic analysis of the gasification employed a comprehensive model, which assumed progress in parallel of non-catalytic and catalytic gasification. The model quantitatively described the measured kinetics of the coke gasification with different SiO<inf>2</inf> contents over a range of coke conversion up to 99.9%. The kinetic analysis revealed that the SiO<inf>2</inf> deactivated substantial and entire portions of the most active catalyst and its precursor, respectively, before the gasification (i.e., during the carbonization). The catalyst deactivation also occurred during the gasification, but mainly following a self-deactivation mechanism that involved no silicates formation.

DOI： 10.1016/j.crcon.2018.09.002

An approach for quantifying transferable hydrogen in pyrolyzing coals 査読有り

Norinaga K., Fukuoka T., Machida H., Zhang W.

36th Annual International Pittsburgh Coal Conference Clean Coal Based Energy Fuels and the Environment PCC 2019 2019年

Reducing energy required for CO2 separation and recovery process by employing phase separation solvents 査読有り

Norinaga K., Nishio H., Khuyen T., Machida H.

36th Annual International Pittsburgh Coal Conference Clean Coal Based Energy Fuels and the Environment PCC 2019 2019年

An approach for quantifying transferable hydrogen in pyrolyzing coals 査読有り

Norinaga K, Fukuoka T, Machida H, Zhang W

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

Reducing energy required for CO<inf>2</inf> separation and recovery process by employing phase separation solvents 査読有り

Norinaga K, Nishio H, Khuyen T, Machida H

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

No.2-19 アミン/エーテル混合吸収剤を用いたCO2分離回収プロセスの省エネルギー化査読有り

町田洋, 西尾仁志, 則永行庸, 江崎丈裕

石炭科学会議発表論文集 55 巻 ( 0 ) 頁： 84 - 85 2018年10月

No.2-30 石炭および熱分解チャーの化学構造および熱分解時ガス発生特性の定量的評価査読有り

福岡鉄也, 町田洋, 則永行庸

石炭科学会議発表論文集 55 巻 ( 0 ) 頁： 110 - 111 2018年10月

Zahara, ZF; Kudo, S; Daniyanto; Ashik, UPM; Norinaga, K; Budiman, A; Hayashi, J

ENERGY & FUELS 32 巻 ( 4 ) 頁： 4255 - 4268 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

A total of 18 chars from the pyrolysis of six trios of sugar cane bagasses (SCBs; original, water-washed, and acid-washed) were gasified with CO<inf>2</inf> at 900 °C, aiming at a quantitative description of the rate of gasification catalyzed by inherent metallic species and a correlation of the catalytic activity and its change during the gasification with the metallic species composition. The measured kinetics was described quantitatively over a range of char conversion, 0-0.999, by a model that assumed progress in parallel of the catalytic gasification and non-catalytic gasification, together with the presence of a catalytic precursor and three to four types of catalysts having different activities and deactivation characteristics. A series of regression analyses was scrutinized and reached expression of initial catalytic activity as a linear function of Na, K, Ca, Fe, and Si concentrations in the char with a correlation factor (r2) of >0.98. The catalyst precursor contributed fully by water-soluble Na, K, and Ca. Si was responsible for the catalyst deactivation during the pyrolysis but not during the gasification. The chars produced from original SCBs followed a linear relationship between the initial catalytic deactivation rate and initial activity (r2 > 0.99), while such a linear relationship was not valid for those formed from the water-washed SCBs. This was explained mainly by more rapid deactivation of the Fe catalyst in the chars from water-washed SCBs than that in the chars formed from the original SCBs. Na and K in char from the original SCBs, originating from the water-soluble SCBs, chemically interacted with the Fe catalyst, slowing its deactivation.

DOI： 10.1021/acs.energyfuels.7b03147

Energy-saving CO2 Capture Process Using Phase Separation Type Solvent by Aqueous (amine + ether) Solution 査読有り

Machida H., Takehiro E., Yamaguchi T., Norinaga K., Kishimoto A., Akiyama K., Nishimura M.

Ghgt 2018 14th International Conference on Greenhouse Gas Control Technologies 2018年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Ghgt 2018 14th International Conference on Greenhouse Gas Control Technologies

We have developed the phase separation solvent for CO<inf>2</inf> capture. Our developed solvent consists amine, organic solvent and water and shows single liquid phase before CO<inf>2</inf> absorption though it shows two liquid phases after CO<inf>2</inf> absorption. Feature of phase separation solvent is reducing temperature difference between absorber and stripper. We apply the heat pump system for CO<inf>2</inf> separation and evaluate the energy consumption. Low temperature swing process saves energy requirement for CO<inf>2</inf> capture process with highly-effective reaction-heat recovering. To evaluate the CO<inf>2</inf> capture system with our solvent, screening test for amine and organic solvent combination and CO<inf>2</inf> solubility measurement were examined. In the phase separation test, three types of solvents were obtained by combining amine and ether, that is, no phase separation with CO<inf>2</inf> scrubbing, phase separation with CO<inf>2</inf> scrubbing, and thoroughly immiscible. The phase behaviour depends on the hydrophobicity of amines or organic solvents, and the types of solvents were classified using the hydrophobic parameter.

Current situation and future scope of biomass gasification in Japan Open Access

Furutani Y., Norinaga K., Kudo S., Hayashi J.I., Watanabe T.

Evergreen 4 巻 ( 4 ) 頁： 24 - 29 2017年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Evergreen

In this study, we investigated current situation of biomass gasification plants in 5 cities (c.a. Murayama City, Chichibu City, Ueno Village, Oshu City and Yamaguchi City) in Japan, and make R&D policy proposals to expand the biomass gasification plants. Four cities have commonly promoted the efficient heat utilization such as snow melting, drying the wood and supplying hot water into mushroom bed and hot spring. However, heat utilization is limited in a small area because heat loss is generated during the long-distance transportation. In order to obtain energy forms suitable for the long-distance transportation, such as hydrogen gas and electricity, the R&D of biomass gasification with hydrogen production or combined with Solid Oxide Fuel Cell (SOFC) should be promoted in the future.

DOI： 10.5109/1929681

7-2-4 相分離型CO2吸収剤による省エネルギーCO2分離技術開発査読有り

町田洋, 江崎丈裕, 山口毅, 堀添浩俊, 則永行庸, 岸本啓, 松岡亮, 秋山勝哉, 西村真

日本エネルギー学会大会講演要旨集 26 巻 ( 0 ) 頁： 228 - 229 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本エネルギー学会

Phase separation type CO2 capture solvent was developed which transforms into two liquid phases after CO2 absorption. At first, we checked the phase phenomena of 9 types of amine and 3 types of polyether combinations. There shows three types; keeping one liquid phase before and after CO2 absorption, transforming into two liquid phase after CO2 absorption, forming initially two liquid phases. CO2 solubility of the developed phase separation solvent was measured. The results show that the phase separation solvent can reduce the temperature difference between absorber and desorber than that of conventional amine solvent. Required energy for CO2 capture using phase separation solvent was estimated under 2.0 GJ/ton-CO2.

DOI： 10.20550/jietaikaiyoushi.26.0_228

A Supported Ni Catalyst Produced from Ni-Al Hydrotalcite-Like Precursor for Reduction of Furfuryl Alcohol to Tetrahydrofurfuryl Alcohol by NaBH4 in Water 査読有り

P-3-3 初期熱分解及び二次気相分解の素反応モデル連成によるリグニン急速熱分解生成物組成の予測査読有り

古谷優樹, 堂原裕騎, 工藤真二, 林潤一郎, 則永行庸

日本エネルギー学会大会講演要旨集 26 巻 ( 0 ) 頁： 268 - 269 2017年

Ren, DZ; Wang, JY; Jiang, XL; Song, ZY; Norinaga, K; Huo, ZB

CHEMISTRYSELECT 6 巻 ( 4 ) 頁： 551 - 556 2021年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistryselect

Tetrahydrofurfuryl alcohol (THFA) is a kind of high value-added compound in industry, which can be obtained from biomass chemical engineering. However, Synthesis of THFA under mild condition with green hydrogen donors remains a big challenge. In this article, a supported Ni catalyst derived from Ni−Al hydrotalcite-like compounds (HTs) as precursors for the reduction of furfuryl alcohol (FA) into THFA with NaBH<inf>4</inf> as reducing agent in water was first reported. As a result, Ni/Al<inf>2</inf>O<inf>3</inf>−HT exhibited high catalytic activity for the transformation, and THFA was achieved in 100 % yield at 60 °C for 60 min. Moreover, Ni/Al<inf>2</inf>O<inf>3</inf>−HT could be recycled at least seven times without the loss of its activity. Under optimized conditions, the reduction reaction of several furan and ketone compounds was investigated. A possible mechanism for the reduction of FA to afford THFA was also proposed.

DOI： 10.1002/slct.202003543

Lattice Boltzmann simulation of multicomponent reaction-diffusion and coke formation in a catalyst with hierarchical pore structure for dry reforming of methane 査読有り Open Access

Lin, YX; Yang, C; Choi, CY; Zhang, W; Machida, H; Norinaga, K

CHEMICAL ENGINEERING SCIENCE 229 巻 2021年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

In order to further enhance catalytic activity and inhibit carbon formation, the hierarchical structure-performance relationship has been investigated in dry reforming of methane (DRM). A modified random generation of macro-mesopores (RGMMP) algorithm was adopted to model the structure of the catalyst with macropore and mesopore. Based on multi-component non-continuum reaction-diffusion lattice Boltzmann model, the effects of three hierarchical pore geometrical parameters, namely the catalyst porosity, the ratio of mesopore volume to macropore volume and the ratio of average macropore diameter to average mesopore diameter, on coke formation and catalytic performance were investigated to elucidate the deactivation and reaction-diffusion mechanism of the catalyst in DRM. Based on the competitive relationship between heterogeneous reaction and intraparticle diffusion, the optimal values to define hierarchical pore structure have been identified, which provides maximum catalytic performance and coking resistance for a reaction condition.

DOI： 10.1016/j.ces.2020.116105

Prediction of Phase Behavior of CO2 Absorbents Using Conductor-like Screening Model for Real Solvents (COSMO-RS): An Approach to Identify Phase Separation Solvents of Amine/Ether/Water Systems upon CO2 Absorption 査読有り

Nakaoka, M; Tran, KVB; Yanase, K; Machida, H; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 59 巻 ( 42 ) 頁： 19020 - 19029 2020年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

Developing energy-saving absorbents for carbon dioxide (CO2) is essential for improving carbon capture and storage (CCS) technologies. Recently, we have designed phase separation solvents, which can significantly reduce the regeneration energy for CO2 capture and separation down to 1.6 GJ/ton-CO2 [ Machida, H.; et al. Int. J. Greenhouse Gas Control2018, 75, 1-7 ]. For further developing better solvents, this paper studied a theoretical approach with conductor-like screening model for real solvents (COSMO-RS) to screen the amine/ether/water systems to identify phase separation solvents upon CO2 absorption. In this work, liquid-liquid equilibria of 21 amine/ether/water systems were determined both before and after CO2 absorption. Experimentally, it has already been demonstrated that the phase behavior of these systems is classified into three categories: phase separation type, miscible type, and immiscible type. This study demonstrates that the octanol/water partition coefficient is empirically able to search for a combination of amine and ether compounds, in which the system exhibits the phase separation behavior by absorbing CO2. The COSMO-RS calculations successfully reproduced experimental phase behavior with a rate of agreement of more than 80% by accounting the following two factors: (i) ion pairing for the description of the association/dissociation state for ionic species and (ii) relevant low-lying conformations of ether and amine, which are rationalized by experiments such as conductivity and excess enthalpy measurements. Moreover, we also validated the ability of the COSMO-RS calculation to qualitatively describe the compositions of 2-(ethylamino)ethanol, diethylene glycol diethyl ether, and water in CO2-rich and CO2-lean phases at varying CO2 loading conditions.

DOI： 10.1021/acs.iecr.0c03233

Energy-Saving CO2 Capture by H2 Gas Stripping for Integrating CO2 Separation and Conversion Processes 査読有り

水素を用いた省エネルギー CO₂ 回収技術招待有り

町田洋，柳瀬慶一，チャンクウィン，山口毅，則永行庸

クリーンエネルギー 29 巻 ( 10 ) 頁： 17 - 22 2020年10月

水素を用いた省エネルギー CO₂ 回収技術招待有り査読有り

町田洋, 柳瀬慶一, チャンクウィン, 山口毅, 則永行庸

クリーンエネルギー 29 巻 ( 10 ) 頁： 17 - 22 2020年10月

メタネーション大規模実証に向けた基盤研究およびCO2分離回収と利用の統合プロセスに関する研究開発招待有り

則永行庸、張煒、チェチョルヨン、柳瀬慶一、チャンクウィン、町田洋

Adsorption News 34 巻 ( 2 ) 頁： 18 - 22 2020年7月

メタネーション大規模実証に向けた基盤研究およびCO2分離回収と利用の統合プロセスに関する研究開発招待有り査読有り

則永行庸, 張煒, チェチョルヨン, 柳瀬慶一, チャンクウィン, 町田洋

Adsorption News 34 巻 ( 2 ) 頁： 18 - 22 2020年7月

Machida, H; Esaki, T; Yamaguchi, T; Norinaga, K

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 8 巻 ( 23 ) 頁： 8732 - 8740 2020年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Sustainable Chemistry and Engineering

CO2 capture and utilization technology, such as converting CO2 to fuel or chemicals by renewable energy-derived H2, has been promoted for recent decades. Herein, a process is proposed that saves considerable amounts of energy by integrating the CO2 separation and conversion processes. In the case of the method of amine absorption, supplying H2 to the bottom of the desorber reduces the regeneration temperature, which can reduce the process exergy. If combined with reaction heat recovery using a heat pump system, a considerable amount of energy can be saved. The recovered mixture of CO2 and H2 gas is then used directly as a raw reaction material. Herein, the proposed stripping regeneration process is compared on theoretical and equilibrium bases, with the conventional monoethanolamine method and the phase-separation solvent method developed by the authors. Using the phase-separation solvent leads to lower energy in the stripping regeneration.

DOI： 10.1021/acssuschemeng.0c02459

Carbon Dioxide Absorption Heat in Liquid-Liquid and Solid-Liquid Phase-Change Solvents Using Continuous Calorimetry 査読有り

Tran, KVB; Ando, R; Yamaguchi, T; Machida, H; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 59 巻 ( 8 ) 頁： 3475 - 3484 2020年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Industrial and Engineering Chemistry Research

For three groups of systems - homogeneous, liquid-liquid, and solid-liquid - absorption heats of carbon dioxide capture by amine solutions were determined with continuous calorimetry. In the case of a phase-separation solvent, the heat of phase separation is added to conventional absorption heat, and the loading range of heat of phase separation is important in process design. With the merits of continuous measurement, the phase-change loading points were obtained in liquid-liquid and solid-liquid phase-separation systems as the heat release of carbon dioxide products to achieve a more stable state. The loading points where a leap in absorption heat appears coincide with those where the turbidity in solvents changes, which was confirmed by ocular inspection in both systems. In liquid-liquid systems, the presence of water in 2-(ethylamino)ethanol:diethylene glycol diethyl ether:water contributes to the decrease in absorption heat. Even though the formation of bicarbonate is minor even in solvent with water, the increase in its formation contributes to this decrease in absorption heat because of its lower formation heat as compared to that of carbamate. In solid-liquid systems, a significant increase in absorption heat is attributed to the crystallization energy of carbonate salt emitted on the breakdown of the supersaturation.

DOI： 10.1021/acs.iecr.9b04672

Computational fluid dynamics simulation of CO2 methanation in a shell-and-tube reactor with multi-region conjugate heat transfer 査読有り

Zhang, W; Machida, H; Takano, H; Izumiya, K; Norinaga, K

CHEMICAL ENGINEERING SCIENCE 211 巻 2020年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

Methanation is one of the promising candidates in developing CO<inf>2</inf> utilization technology. Because of its exothermic behavior, the methanation reactor must be carefully designed to avoid the hotspots formation and the deterioration of catalysts. This study presents a numerical study simulates heat transfer between the reacting gas in a porous catalyst layer, reactor tube, and coolant in a shell-and-tube reactor. The aim is to develop a tool can predict the hotspots appearing in the reactor used in CO<inf>2</inf> methanation. The open-source toolbox OpenFOAM is adopted and modified. The catalyst bed is assumed to be a continuous porous medium. The results revealed that the solver captures the trends of temperature profiles along both axial and radial directions. The maximum catalyst temperature predicted by this solver is in good agreement with the experimental result, indicating that the solver is a promising tool for future applications in reactor optimization and heat management.

DOI： 10.1016/j.ces.2019.115276

Quantitative Description of Catalysis of Inherent Metallic Species in Lignite Char during CO2 Gasification 査読有り

Modelling of CO<inf>2</inf> solubility in phase separation solvent composed of amine/ether/water system for CO<inf>2</inf> capture 査読有り Open Access

Machida, H., Ando, R., Esaki, T., Yamaguchi, T., Norinaga, K.

Journal of Molecular Liquids 292 巻 2019年10月

Halim, N; Ashik, UPM; Gao, XP; Kudo, S; Sanwani, E; Norinaga, K; Hayashi, J

ENERGY & FUELS 33 巻 ( 7 ) 頁： 5996 - 6007 2019年7月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

Chars from 20 lignite samples were prepared from two types of original lignites by multistage removal of inherent metallic species and subsequent pyrolysis and then were gasified with CO<inf>2</inf>. A kinetic model, which assumed the progress of noncatalytic and catalytic gasification in parallel, quantitatively described the time-dependent changes in char conversion up to 0.999 for all the chars by employing multicatalytic species having different initial activities and deactivation kinetics. A single piecewise linear function, which followed a nucleation-growth mechanism of the catalysts, showed the relationship between the total concentration of Na, K, Ca, and Fe and the initial total catalytic activity (ICA-2) for the chars. The overall rate of catalyst deactivation (ICD-2) was given by a single linear function of ICA-2 and a factor for the composition of metallic species. This function was also applicable to previously reported ICA-2/ICD-2 relationships for chars from lignite and biomass, showing fast deactivation of Fe catalyst and an important role of Mg in the promotion of catalyst deactivation.

DOI： 10.1021/acs.energyfuels.9b00465

Production of High-strength Cokes from Non-/Slightly Caking Coals. Part I: Effects of Coal Pretreatment and Variables for Briquetting and Carbonization on Coke Properties 査読有り Open Access

Matoba, M; Kudo, S; Mori, A; Norinaga, K; Uchida, K; Dohi, Y; Uebo, K; Hayashi, J

ISIJ INTERNATIONAL 59 巻 ( 8 ) 頁： 1440 - 1448 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

In continuation of the present authors' studies on production of high strength coke from lignite by sequential binderless hot briquetting and carbonization, this study has been carried out aiming at proposing methods to produce high strength coke from non-/slightly caking coals of subbituminous to bituminous rank. This paper firstly demonstrates preparation of cokes with cold tensile strengths above 10 MPa from two single non-caking coals (particle size; < 106 μm) by applying briquetting at temperature and mechanical pressure of over 200°C and 100 MPa, respectively. Such strength of coke is obtained over a wide range of heating rate, 3-30°C/min, during carbonization with final temperature of 1 000°C. Then, a simple pretreatment, fine pulverization of coal to particle sizes smaller than 10 or 5 μm, is examined. This pretreatment enables to prepare coke with tensile strength even over 25 MPa, by decreasing porosity of resulting coke and more extensively the size of macropores simultaneously. The coke strength changes with carbonization temperature having a particular feature; significant development of strength at 600-1 000°C, i.e., after completion of tar evolution, in which macropores and non-porous (dense) part of coke shrink in volume, inducing bonding and coalescence of particles and thereby arising the strength.

DOI： 10.2355/isijinternational.ISIJINT-2018-819

Quantitative Analyses of Chemical Structural Change and Gas Generation Profile of Coal upon Heating toward Gaining New Insights for Coal Pyrolysis Chemistry 査読有り Open Access

Fukuoka, T; Takeda, N; Zhang, L; Machida, H; Zhang, W; Watanabe, M; Nishibata, Y; Hayashi, J; Norinaga, K

ISIJ INTERNATIONAL 59 巻 ( 8 ) 頁： 1376 - 1381 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

Chemical structure of coal is evolutionary changed during pyrolysis that accompanies gas release. The chemical structural change and gas formation profiles play important roles in determining caking property and physical properties such as strength and size of the resultant coke. However, analyses of volatile components and structural analysis of solid char have been mostly performed individually, and it is difficult to combine both and to obtain quantitative understanding on the thermal decomposition of coal at mechanistic level. In this study, simultaneous analyses of solid chemical structures of the heat treated coals and gas formation profiles were conducted for two kinds of coals that were pyrolyzed at an identical condition. On-line gas analysis with a quadrupole mass spectrometer and spectroscopic methods (NMR and FT-IR) were employed for quantitative evaluation of gas formation characteristics and solid chemical structure, respectively. The information obtained were then integrated to acquire new insight for coal pyrolysis mechanism. Here an approach to quantify the transferable hydrogen that contributes to stabilize radicals formed in pyrolyzing coal was proposed. It includes the quantitative assessment of aromatic cluster growth, decomposition of hydroxyls, and releases of hydrogen and pyrolytic water into gas phase. The proposed approach suggested that a bituminous coal that exhibits plasticity during pyrolysis had 3.5 mol/kg-coal transferable hydrogen, whereas the amount of transferable hydrogen of the sub-bituminous coal, a non-caking coal, was 1.3 mol/kg-coal, during pyrolysis up to 500°C.

DOI： 10.2355/isijinternational.ISIJINT-2018-816

Production of High-strength Cokes from Non-and Slightly Caking Coals. Part II: Application of Sequence of Fine Pulverization of Coal, Briquetting and Carbonization to Single Coals and Binary Blends 査読有り Open Access

Uchida, K; Kudo, S; Mori, A; Ashik, UPM; Norinaga, K; Dohi, Y; Uebo, K; Hayashi, J

ISIJ INTERNATIONAL 59 巻 ( 8 ) 頁： 1449 - 1456 2019年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ISIJ International

Sequential coal briquetting and carbonization was applied to preparation of cokes from 9 non- or slightly caking coals with carbon contents (f<inf>C</inf>) of 67-85 wt%-daf. Coal pulverization to sizes of <106 μm and briquetting at 40°C enabled to prepare cokes with tensile strength (σ) over 10 MPa from 4 coals with f<inf>C</inf> of 82-85 or 67 wt%-daf. Then, by introducing fine pulverization to sizes of < 10 μm before the briquetting, 7 coals were converted successfully into cokes with σ = 11-25 MPa. Increasing the briquetting temperature to 240°C further increased σ to 19-35 MPa for all the 9 coals. It was thus demonstrated that the hot briquetting of finely pulverized coal was a method to prepare high strength coke regardless of the rank of parent coal. Cokes were also prepared from 14 binary coal blends. All the cokes prepared by applying the fine pulverization and hot briquetting had σ of 20-35 MPa, which agreed well with that calculated by weighted average of those from the component coals. On the other hand, positive and also negative synergistic effects of blending occurred when blends were briquetted at 40°C. Characteristics of bonding/ coalescence among particles of different types of coals were responsible for such synergies.

DOI： 10.2355/isijinternational.ISIJINT-2018-847

An approach for quantifying transferable hydrogen in pyrolyzing coals 査読有り

Norinaga K

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

Reducing energy required for CO<inf>2</inf> separation and recovery process by employing phase separation solvents 査読有り

Norinaga K

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

An approach for quantifying transferable hydrogen in pyrolyzing coals 査読有り

Norinaga K

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

Reducing energy required for CO<inf>2</inf> separation and recovery process by employing phase separation solvents 査読有り

Norinaga K

36th Annual International Pittsburgh Coal Conference: Clean Coal-Based Energy/Fuels and the Environment, PCC 2019 2019年

Characteristics of gas evolution profiles during coal pyrolysis and its relation with the variation of functional groups 査読有り Open Access

Zhang L., Qi S., Takeda N., Kudo S., Hayashi J., Norinaga K.

International Journal of Coal Science and Technology 5 巻 ( 4 ) 頁： 452 - 463 2018年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Coal Science and Technology

Strict relation between the substituents or functional groups attached to the coal macromolecules and the generation of the volatile products, e.g., CH<inf>4</inf>, H<inf>2</inf>O, CO, CO<inf>2</inf>, etc., during the coal pyrolysis is an important but confusing subject. In this paper, quadrupole mass spectrometry, gas chromatography, and 13C nuclear magnetic resonance are applied to real-time monitoring the formations of volatile products, off-line quantitative determination of the total products from the pyrolysis of a sub-bituminous coal (SC), and the changes of diverse substitents in the SC along with coke foamation, respectively. These measurements are also performed for the pyrolysis of a caking coal to contrast SC. The qualitative and quantitative data reveal that, during coal pyrolysis, the functional groups related with the formation of CO, i.e., ether, carbonyl, and anhydride, can directly generate CO via bond breaking, or take a detour of the formation of other intermediates via condensation and recombination firstly. Moreover, the formations of CO<inf>2</inf> and CH<inf>4</inf> are related to the direct removal of -COO- and -CH<inf>3</inf>, respectively.

DOI： 10.1007/s40789-017-0175-0

Effects of HZSM-5 on volatile products obtained from the fast pyrolysis of lignin and model compounds 査読有り

Yang, HM; Norinaga, K; Li, J; Zhu, WY; Wang, HJ

FUEL PROCESSING TECHNOLOGY 181 巻頁： 207 - 214 2018年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel Processing Technology

This study aimed to experimentally investigate the effect of HZSM-5 on the distribution of volatile products, especially carbon monoxide (CO), C<inf>1</inf>–C<inf>5</inf> hydrocarbons and aromatic hydrocarbons (AHs) during catalytic pyrolysis of lignin and lignin model compounds. Catechol was pyrolyzed using a two-stage tubular reactor (TS-TR) connected to a gas chromatography system over HZSM-5 at 550–950 °C. Forty-three products, including four inorganic gases, twenty C<inf>1</inf>–C<inf>5</inf> hydrocarbons, and nine AHs were quantified using three GC-columns. Results indicated that HZSM-5 accelerated the catechol conversion with a large amount of CO and AHs produced. C<inf>1</inf>–C<inf>5</inf> hydrocarbons were formed during non-catalytic pyrolysis of model compounds, and consumed quickly during HZSM-5 catalytic pyrolysis of catechol. Catalytic pyrolysis of phenol, guaiacol and syringol was carried out at 650 °C in the TS-TR over HZSM-5. HZSM-5 obviously promoted the conversion of lignin model compounds, and largely increased the yield of volatile products especially CO and AHs. Three lignin samples were also catalytically pyrolyzed over HZSM-5 in the TS-TR at 650 °C. HZSM-5 increased the yield of C<inf>2</inf>-C<inf>3</inf> hydrocarbons and AHs, and reduced the yield of oxygenated compounds. HZSM-5 could promote the formation of AHs (lower than 10 wt%) during lignin pyrolysis, but not as obviously as during model compounds pyrolysis (higher than 19 wt%). High yields of char and tar would account for the low catalytic efficiency of HZSM-5 during lignin pyrolysis.

DOI： 10.1016/j.fuproc.2018.09.022

Prediction of hot coke oven gas reforming by LES coupled with the extended flamelet/progress variable approach 査読有り

Yu, PL; Norinaga, K; Watanabe, H; Kitagawa, T

FUEL 231 巻頁： 234 - 243 2018年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel

Large-eddy simulation (LES) coupled with the extended flamelet/progress variable approach (EFPV) has been performed to predict characteristics of reacting flows in a bench-scale hot coke oven gas (HCOG) reformer. In order to investigate the capability of capturing effects of operating conditions, simulations were carried out in two different cases in which the coke oven gas temperature and oxygen ratio were altered. Results showed that the LES coupled with the EFPV performed very well in terms of predicting temperature distribution as well as the temperature variation trend between the two cases. In addition, major species such as H<inf>2</inf>, CO, CO<inf>2</inf>, H<inf>2</inf>O and CH<inf>4</inf>, as well as minor species like benzene and some typical polycyclic aromatic hydrocarbons (PAH) were analyzed to illustrate their activities and dominant chemical events. With regards to the composition of the dry reformed gas, comparisons were made between the experimental data and the numerical simulation results, and reasonable results have been obtained. It has been confirmed that the general feature of the reacting flows in the HCOG reformer can be precisely captured by the present LES.

DOI： 10.1016/j.fuel.2018.05.104

Characteristic Properties of Lignite To Be Converted to High-Strength Coke by Hot Briquetting and Carbonization 査読有り

Kudo, S; Mori, A; Hayashi, G; Yoshida, T; Okuyama, N; Norinaga, K; Hayashi, J

ENERGY & FUELS 32 巻 ( 4 ) 頁： 4364 - 4371 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

A sequence of hot briquetting and carbonization (HBC) is a promising technology for the production of coke with a high mechanical strength from lignite, but factors affecting the coke strength have not yet been fully understood. The HBC cokes prepared from 12 lignites in this study showed diverse tensile strength (e.g., from 0.2 to 31.2 MPa in the preparation at 200 °C and 112 MPa for hot briquetting and 1000 °C for carbonization), and the coke strengths could not be explained by differences in commonly used structural properties of the parent lignites, such as elemental composition and contents of volatile matter/fixed carbon and ash. In this study, two methods were proposed for correlating the coke strength with the lignite properties, which employed the chemical structure analyzed by solid-state 13C nuclear magnetic resonance or the volumetric shrinkage during carbonization. A stronger coke was obtained from lignite that contained more aliphatic carbons (less aromatic carbons) or shrank more considerably. These characteristics contributed to intensified compaction of lignite in the briquetting and suppression of the formation of large pores, which are a cause of coke fracture. Two empirical equations, predicting the coke strength from the parameters of lignite properties, were established to be criteria for selection of lignite as HBC coke feedstock, although further investigation with more experimental data would be necessary for the validation.

DOI： 10.1021/acs.energyfuels.7b03155

Computational Study on the Thermal Decomposition of Phenol-Type Monolignols 査読有り

Furutani, Y; Dohara, Y; Kudo, S; Hayashi, JI; Norinaga, K

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS 50 巻 ( 4 ) 頁： 304 - 316 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Chemical Kinetics

A detailed chemical kinetic model has been developed to theoretically predict the pyrolysis behavior of phenol-type monolignol compounds (1-(4-hydroxyphenyl)prop-2-en-1-one, HPP; p-coumaryl alcohol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, HHPP; 1-(4-hydroxyphenyl)propane-1,3-diol, HPPD) released from the primary heterogeneous pyrolysis of lignin. The possible thermal decomposition pathways involving unimolecular decomposition, H-addition, and H-abstraction by H and CH<inf>3</inf> radicals were investigated by comparing the activation energies calculated at the M06–2X/6–311++G(d,p) level of theory. The results indicated that all phenol-type monolignol compounds convert to phenol by side-chain cleavage. p-Coumaryl alcohol decomposes into phenol via the formation of 4-vinylphenol, whereas HPP, HHPP, and HPPD decompose into phenol via the formation of 4-hydroxybenzaldehyde. The pyrolytic pathways focusing on the reactivity of the hydroxyl group in HPP and producing cyclopentadiene (cyc-C<inf>5</inf>H<inf>6</inf>) were also investigated. The transition state theory (TST) rate constants for all the proposed elementary reaction channels were calculated at the high-pressure limit in the temperature range of 300–1500 K. The kinetic analysis predicted the two favorable unimolecular decomposition pathways in HPP: the one is the dominant channel below 1000 K to produce cyc-C<inf>5</inf>H<inf>6</inf>, and the other is above 1000 K to yield phenol (C<inf>6</inf>H<inf>5</inf>OH).

DOI： 10.1002/kin.21164