Faculty Profiles - NORINAGA Koyo

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

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

SEPARATION AND PURIFICATION TECHNOLOGY Vol. 355 2025.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Separation and Purification Technology

Carbon capture and utilization (CCU) has attracted considerable interest recently as CO2 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 CO2-loaded amine solutions into CO. The effects of the electrodes, temperature, potential, and CO2 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 CO2-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 CO2, 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 CO<inf>2</inf> methanation process and techno-economic analysis with CO<inf>2</inf> capture from the flue gas of automotive shredder residue Reviewed

Wasnik C.G., Nakamura M., Machida H., Ito J., Shiratori K., Norinaga K.

Chemical Engineering Journal Vol. 507 2025.3

Language：English Publishing type：Research paper (scientific journal) Publisher：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, CO2 capture from exhaust gas through chemical absorption, and production of synthetic methane (CH4) using the captured CO2 and renewable hydrogen produced via water electrolysis powered by renewable energy sources. This process produces not only CH4 but also surplus electricity, which can be used to produce H2 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 CH4 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 CO2 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

CO<inf>2</inf> methanation over low-loaded Ni-M, Ru-M (M = Co, Mn) catalysts supported on CeO<inf>2</inf> and SiC Reviewed Open Access

Wasnik C.G., Nakamura M., Shimada T., Machida H., Norinaga K.

Carbon Resources Conversion Vol. 8 ( 1 ) 2025.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Carbon Resources Conversion

The concentration of the major greenhouse gas CO2 is rapidly increasing in the atmosphere, leading to global warming and a range of environmental issues. An efficient circulation and utilization of CO2 is critical in the current environmental context. Methanation, an exothermic process, emerges as a critical strategy for effective CO2 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 CeO2, 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 CO2 conversion rate of 77 % and CH₄ selectivity of 88 % at 500 °C, in a fixed-bed tubular reactor system with conditions of H2/CO2 = 4, a total flow rate of 70 ml min−1, and a steady GHSV of 12,000 h−1. Moreover, 2Ni-2Co/CeO2 catalyst demonstrated exceptional performance with a 76 % conversion of CO2 and a 83 % selectivity for CH4, 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, H2-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

Open Access

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

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

CHEMICAL ENGINEERING SCIENCE Vol. 305 2025.2

Language：English Publishing type：Research paper (scientific journal) Publisher：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 CO2 capture process leveraging LNG's cryogenic temperatures to create a vacuum environment, recovering CO2 from amine-based solutions as dry ice. CO2 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 CO2 was supplied to the shell side. CO2 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

Open Access

Nickel/Zirconia-Catalyzed CO2 Methanation in Differential and Integral Fixed-Bed Reactors: Experimental and Computational Fluid Dynamics Studies Reviewed

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

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH Vol. 64 ( 3 ) page： 1473 - 1487 2025.1

Language：English Publishing type：Research paper (scientific journal) Publisher：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/ZrO2 catalyst bed were minimized using α-Al2O3 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 Reviewed

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

APPLIED THERMAL ENGINEERING Vol. 258 2025.1

Language：English Publishing type：Research paper (scientific journal) Publisher：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

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

Xu C., Liu P., Peng Y.L., Dou M., Jiang Q., Jia X., Zhang Y., Norinaga K.

Industrial and Engineering Chemistry Research 2025

Language：English Publishing type：Research paper (scientific journal) Publisher：Industrial and Engineering Chemistry Research

Understanding the amine distribution within solid amine sorbents is crucial for enhancing their amine utilization and ultimately improving the CO2 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, SO2 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 CO2 adsorption capacity by maximuming the accessible amine cont within the sorbent particles.

DOI： 10.1021/acs.iecr.4c05007

1-07　Techno-Economic Analysis on Synthesis of Tetrahydrofurfuryl Alcohol by Furfural Hydrogenation Reviewed

UEHARA Yusuke, LI Qiao, RAO Thuppati Upender, MACHIDA Hiroshi, NORINAGA Koyo

Proceedings of Conference on Coal Science Vol. 61 ( 0 ) page： 14 - 15 2024.10

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

Efficient conversion of biomass-derived furfural into high value-added chemicals such as tetrahydrofurfuryl alcohol (THFA) by hydrogenation has received much attention in terms of post-fossil fuel and energy saving. While many researchers have put their efforts on developing cost-effective catalysts for furfural hydrogeneration, only little investigations have been reported on its techno-economic analysis as well as process optimization. This study aims to design an energy saving process model of furfural hydrogeneration for THFA synthesis coupled with thermal recovery system consisting of organic Rankine cycle and heat pump, and to evaluate energy efficiency and economics of the proposed process through Aspen simulation, based on our previous experimental data with Ni1Cu1-Al1 catalyst.

DOI： 10.20550/jiesekitanronbun.61.0_14

1-03　Conversion of carbon dioxide to ethylene by electrolytic reduction using perovskite catalysts Reviewed

Suchada SIRISOMBOONCHAI, Norinaga KOYO

Proceedings of Conference on Coal Science Vol. 61 ( 0 ) page： 6 - 7 2024.10

Language：English Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

The electrochemical CO2 reduction reaction (eCO2RR) offers a sustainable method for reducing greenhouse gas emissions by converting CO2 into valuable chemicals and fuels without requiring extreme conditions. Electrocatalysts play a significant role in this process by producing carbon-based products such as ethylene, etc. Perovskite oxides have emerged as promising electrocatalysts due to their high ionic/electronic structure, stability, ability to vary elements, and the alkaline earth effect, which enhances the *CO2 - intermediate. Specifically, Ca is the A-site in coordination with the Cu-site, providing Ca2CuO3 with strong basic strength and exceptional CO2 adsorption capabilities. The Ca2CuO3 catalyst demonstrates significant efficiency in converting CO2 to C2H4, exceeding FEC2H4 50% at 100 mA/cm2. This research represents an attractive advancement in realizing the conversion of CO2 to C2H4.

DOI： 10.20550/jiesekitanronbun.61.0_6

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

Li, Q; Machida, H; Norinaga, K

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH Vol. 63 ( 44 ) page： 19063 - 19075 2024.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Industrial and Engineering Chemistry Research

Liquid hydrogen (LH2) 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 LH2, 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　Investigation of numerical conditions for heat transfer in a CO2 sublimation tank Reviewed

YAMAGUCHI Hiroyasu, UEHARA Yusuke, MACHIDA Hiroshi, NORINAGA Koyo, SAITO Yasuhiro

Proceedings of the Annual Conference of The Japan Institute of Energy Vol. 33 ( 0 ) page： 244 - 245 2024.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

Numerical simulations for cooling of CO2 gas around a cold plate in a laboratory-scale sublimation tank were performed to investigate the effect of the heat flux from the plate and the initial temperatures of the CO2 gas on the temperature distribution. The results showed that the heat flux of the plate had a minimal impact on the temperature distribution in the tank. The effect of the heat of sublimation of CO2 on the temperature distribution in the tank would be significantly large.

DOI： 10.20550/jietaikaiyoushi.33.0_244

6-2-4　Development of Atomically Dispersed Ni Catalyst on N-doped Carbonized Lignin for Highly Efficient Electrochemical CO2 Reduction Reviewed

Park Gi-Dong, Suchada Sirisomboonchai, Norinaga Koyo

Proceedings of the Annual Conference of The Japan Institute of Energy Vol. 33 ( 0 ) page： 166 - 167 2024.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

The Ni single-atom catalysts (SACs) on N-doped carbon are promising electrocatalyst for the electrochemical CO2 reduction (CO2R), owing to their unique electrocatalytic properties. However, conventional methods to fabricate SACs are not environmentally friendly. To overcome it, we utilized lignin for preparing Ni SAC, which is derived from biomass. Furthermore, the coordination number of Ni−NxC sites was regulated to investigate the effects of change in geometrical/electronic nature on catalytic behaviors. The Ni SAC on lignin-derived N-doped carbon performed an CO Faradaic efficiency of 98.2 % at −0.9 V vs. RHE, in H-type cell configuration. Along with experimental results, DFTbased theoretical calculations elucidated the reasons for the enhanced CO2R performance, depending on the different coordination environments of Ni−NxC sites.

DOI： 10.20550/jietaikaiyoushi.33.0_166

6-2-2　Study on methane synthesis process using treated gas from automobile shredder dust as feedstock Reviewed

Nakamura Maki, Li Qiao, Chopendra G. Wasnik, Norinaga Koyo

Proceedings of the Annual Conference of The Japan Institute of Energy Vol. 33 ( 0 ) page： 162 - 163 2024.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

This study proposes a rational process aimed at carbon recycling to effectively recycle carbon dioxide (CO2) emitted from automobile shredder residue (ASR). The methods investigated include direct methane synthesis from ASR process gas and methane synthesis from CO2 recovered by chemical absorption using a gas engine cogeneration system. By optimizing the type and operating conditions of these reactors, it was found that the methane synthesis cost can be reduced by using CO2 recovered through chemical absorption in the methane synthesis process.

DOI： 10.20550/jietaikaiyoushi.33.0_162

6-2-3　Development Of CO2 Methanation Catalysts Supported On CeO2 And SiC At Elevated Temperatures Reviewed

Chopendra G. Wasnik, Nakamura Maki, Shimada Taiki, Machida Hiroshi, Norinaga Koyo

Proceedings of the Annual Conference of The Japan Institute of Energy Vol. 33 ( 0 ) page： 164 - 165 2024.7

Language：English Publishing type：Research paper (scientific journal) Publisher：The Japan Institute of Energy

The increasing concentration of CO2 in the atmosphere is a major environmental concern, and effective utilization of CO2 is crucial. In this context, efficient circulation and utilization of CO2 are paramount. The methanation process emerges as a critical strategy for effective CO2 utilization. The methanation is an exothermic reaction. Therefore, catalysts that uphold high activity and methane selectivity over a wide temperature range are in significant demand. This study investigated 2Ni-2Co/SiC and 2Ni-2Co/CeO2 bimetallic catalysts, using only 20 mg of the sample. The experiments were carried out in a fixed-bed tubular reactor at a steady GHSV of 12,000 h-1. The results showed that the catalyst 2Ni-2Co/SiC showed 77% conversion of CO2 with an 88% CH4 selectivity, while 2Ni-2Co/CeO2 demonstrated 76% CO2 conversion and 83% selectivity for CH4 at 500°C. These bimetallic catalysts have high activity for Ni and Ru, with resistance to Co and Mn carbon deposition, and can withstand high temperatures up to 500°C without losing activity, selectivity, and thermal stability. The catalysts were characterized through multiple tests, to unveil their physicochemical properties. The Co and Mn have effectively restrained the Ni and Ru agglomeration, optimized metal dispersion, and enhanced catalytic activity even in high-temperature environments.

DOI： 10.20550/jietaikaiyoushi.33.0_164

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

Discussion Reviewed

NODA Reiji, NORINAGA Koyo, FUSHIMI Chihiro, ENOMOTO Hiroshi, HOSOKAI Sou, OTA Tomohisa

Nihon Enerugii Gakkai Kikanshi Enermix Vol. 103 ( 4 ) page： 422 - 431 2024.7

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

ENERGY & FUELS Vol. 38 ( 14 ) page： 13089 - 13103 2024.7

Language：English Publishing type：Research paper (scientific journal) Publisher：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 CO2 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 CO2, 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 CO2 capture and utilization but inferior in high production costs.

DOI： 10.1021/acs.energyfuels.4c01250

Energy optimization of a non-aqueous solvent CO2 absorption system with pressure swing regeneration Reviewed

Environmental-friendly extraction of di(2-ethylhexyl) phthalate from poly (vinyl chloride) using liquefied dimethyl ether Reviewed Open Access

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

WASTE MANAGEMENT Vol. 183 page： 21 - 31 2024.6

Language：English Publishing type：Research paper (scientific journal) Publisher：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

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

INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL Vol. 135 2024.6

Language：English Publishing type：Research paper (scientific journal) Publisher：International Journal of Greenhouse Gas Control

This study focuses on optimizing the energy requirement in the post-combustion CO2 capture system using pressure swing regeneration through a model-based design (MBD). The simulation results highlight the significant impact of CO2 recovery, inlet gas and liquid flow rate, and CO2 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 CO2 in the heat exchanger. The parametric analysis study reveals that the sensible heat of the lean solvent is significantly influenced by the CO2 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 CO2, 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 Reviewed

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

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH Vol. 63 ( 13 ) page： 5823 - 5832 2024.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Industrial and Engineering Chemistry Research

CO2 solubility is one of the key factors in evaluating not only the efficiency of the absorbent but also the energy consumption of the CO2 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 CO2 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 CO2 solubility data of benchmark amine solutions. Distinct from conventional measurement methods of CO2 solubility, high-throughput CO2 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 CO2 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 CO2 solubility curves measured by this system also agrees well with the experimental data.

DOI： 10.1021/acs.iecr.3c03314