研究者詳細 - 則永　行庸

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

CO2 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 CO2 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 CO2 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 (CO2) 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

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

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 CO2 reduction reaction (CO2RR), 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−Nx 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 CO2-to-CO conversion and the effect of the electronic structure of Ni atom on CO2RR 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 CO2 content reservoirs facing the emission of a large amount of CO2. CO2 methanation is recognized as one of the suitable candidates for CO2 utilization to reduce the emission of CO2. 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 CO2 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 CO2 with coal into coal gasifier is a promising approach to achieve CO2 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 CO2 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, O2/CO2, O2/H2O) in a two-stage entrained flow coal gasifier using a detailed chemical kinetic model (DCKM). Under the O2/CO2– and O2/H2O-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 O2/CO2-blown condition, while the somewhat effect was found in the O2/H2O-blown condition. Tar yield peaked at 50% relative oxygen concentration in the O2/CO2-blown condition. The present finding may have practical significance in the O2/CO2-blown gasifier to facilitate CO2 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 N2 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, CH3SiCl3)/H2 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 CH3SiCl3(MTS)/H2 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 [H2]/[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 (V2/V1) and hierarchical pore size ratio (d2/d1). The results indicated that increasing V2/V1 and d2/d1 can significantly promote permeability. Under the restriction ofV2/V1 = 4, from d2/d1 = 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 (d2/d1), the hierarchical pore volume ratio (V2/V1), 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 (Tave = 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 AlOx and sets up charge transfer in Ni-AlOx 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 AlOx with oxygen vacancy improves the charge density in Ni-AlOx interface and enhances the adsorption of fatty acid, facilitating the hydrodeoxygenation process. Benefiting from these attributes, Ni–Al0.33Ox 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–Al0.33Ox 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 CO<inf>2</inf> 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

CO2 methanation, which converts CO2 and hydrogen into methane as fuel, is one of the promising candidates for the development of CO2 utilization technologies. Recently, a highly active catalyst made of Ni/ZrO2 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 CO2 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