Comparative Performance Assessment of Adsorbents for CO2 Capture via Physisorption in a Diesel Engine Exhaust

The atmospheric carbon dioxide (CO₂) concentration has been consistently increasing each year throughout the world. Internal combustion (IC) engines are significant contributors to CO₂ emissions. This study explores the possibility of employing effective biomass-based adsorbents to mitigate CO₂ from a diesel engine exhaust. As a first step, two distinct agro-wastes, namely, i) corn cob and ii) sugarcane bagasse, are used to prepare inexpensive and efficient activated carbons. The two main steps in the activated carbon preparation are a) carbonization and b) activation. The derived activated carbons are subjected to discrete analytical techniques to examine their structural and textural characteristics, surface functional groups, and physical, chemical, and adsorptive properties. As a second step, the exhaust treatment chamber unit is filled with the adsorbents one by one and is connected to the exhaust of the constant pressure heat addition engine. A single-cylinder, four-stroke, naturally-aspirated, air-cooled, direct injection (DI) compression ignition (CI) engine is used in the experimental investigations. The essential findings show that ≈68 and 60% of CO₂ emissions are adsorbed in the test engine by utilizing corn cob and sugarcane bagasse adsorbents, respectively. The results show that during the D100 and JME20 operations, the prospective adsorbents can curb more than 40% of overall CO₂ emissions.