Study on Direct CO₂ Capture from Motorcycle Exhaust Gases (Part II)
-Influence of Coexisting Species on CO₂ Adsorption Performance-

Momona Hirao･Shogo Hashimoto･Toru Uenishi (Kitami Institute of Technology)

In our previous study, we demonstrated that carbon dioxide emitted from motorcycles can be directly captured, and we showed that while zeolites exhibit reduced CO₂ adsorption capacity compared with model-gas conditions, amine-impregnated silica exhibits improved performance. In this study, to clarify the factors responsible for this difference, we conducted model-gas experiments to investigate the influence of individual coexisting species on CO₂ adsorption capacity. The results provide insight into how specific exhaust components affect adsorption behavior and contribute to the development of more practical on-board CO₂ capture systems.

Study on On-Board Carbon Recycling Technology (Part II)
-Effect of Secondary Particle Size on Reverse Water–Gas Shift Activity under an Electric Field-

Koki Fujiwara･Toru Uenishi (Kitami Institute of Technology)

In our previous study, we demonstrated that the reverse water–gas shift (RWGS) reaction under an applied electric field can proceed under exhaust-gas conditions, indicating its potential for on-board carbon recycling. For practical implementation, establishing design guidelines for the particle size of catalyst supports used in the reactor is essential. In this study, we investigated the influence of the secondary particle size (aggregate size) of the catalyst support on RWGS activity under an electric field. The results provide insight into how support morphology affects reaction performance and offer guidance for designing reactors for on-board carbon recycling systems.

Study on Direct CO₂ Capture from Motorcycle Exhaust Gases (Part III)
-Effect of Adsorbent Hydrophobicity on CO₂ Adsorption Performance-

Hayato Enjo･Momona Hirao･Toru uenishi (Kitami Institute of Technology)

In our previous study, we investigated the effects of coexisting gases on CO₂ adsorption capacity and showed that water vapor enhances adsorption performance. For practical implementation of on-board CO₂ capture systems, it is necessary to establish design guidelines for binders used to coat adsorbents onto honeycomb supports and other structures. In this study, we examined the influence of binder materials on CO₂ adsorption capacity under humid conditions, focusing on how the hydrophobicity of the adsorbent layer affects adsorption behavior. The results provide insights that contribute to developing practical binder formulations for on-board CO₂ capture applications.

Study on Direct CO₂ Capture from Motorcycle Exhaust Gases (Part IV)
-Effect of Adsorbent Impregnation Methods on CO₂ Adsorption Performance-

Shogo Hashimoto･Momona Hashimoto･Toru Enjo･Toru Uenishi (Kitami Institute of Technology)

In our previous study, we examined the influence of binder materials on CO₂ adsorption and showed that binder hydrophobicity plays a key role in the enhancement of adsorption under humid conditions. For practical implementation of on-board CO₂ capture systems, it is important to establish design guidelines for the impregnation methods used for preparing adsorbent layers. In this study, we investigated how different impregnation methods affect CO₂ adsorption capacity in the presence of water vapor. The results provide insight into the relationship between impregnation technique and adsorption behavior, contributing to the development of practical adsorbent preparation methods.

CO₂ Separation and Capture from Engine Exhaust Gas Using the Physical Adsorption Method (Third Report)
-Impact of use of biomass-fuel on CO₂ adsorption and desorption performance-

Tadanori Yanai (Shizuoka Institute of Science and Technology)

A CO₂ separation and capture system using a physical adsorption method with zeolite for internal combustion engines has been developed. However, influence of exhaust gas properties generated from biomass-fuels on the CO₂ capture performance has not yet been understood. In this study, impact of use of ethanol fuel in a spark ignition engine on the CO₂ adsorption and desorption performance was investigated.

CO2 Absorption Method in the Exhaust Gas by Droplet Impingement/Atomization Control of Absorbent using Surface Texturing (Second Report)
-Possibility of CO2 Absorption Efficiency by Combining Chemical Absorption and Physical Adsorption Methods-

Tetsuo Nohara･Yuki Kawamoto･Naoya Fukushima･Masayuki Ochiai (Tokai University)

In a previous report, we investigated a CO2 absorption method using a chemical absorption method that utilizes droplet impingement and atomization on a surface-textured plate, and confirmed the CO2 absorption efficiency at room temperature. In this report, in addition to these, we compared different gas temperatures/impingement plate temperatures. We discovered the possibility of a new CO2 absorption and capture system that combines a physical adsorption method using a CO2 adsorbent installed at the last position.

Research on On-board CO2 Capture Technology (3rd Report)
-Deriving System Requirements Using Machine Learning-

Junya Murata･Hirotsugu Matsuda･Daichi Takashima･Yuji Harada (Mazda)

In constructing a CO2 capture system from engine exhaust gas, it is necessary to derive the requirements for multiple factors that affect capture performance in order to achieve the target CO2 capture amount. However, an analysis using only 1D-CFD requires an enormous amount of computation time. Therefore, we utilized a machine learning model trained on 1D-CFD results to efficiently derive the system requirements.