Experimental Investigations on CO ₂ Recovery from Engine Exhaust Using Adsorption Technology

Energy policy reviews state that automobiles contribute 25% of the total Carbon dioxide (CO₂) emission. The current trend in emission control techniques of automobile exhaust is to reduce CO₂ emission. We know that CO₂ is a greenhouse gas and it leads to global warming. Conversion of CO₂ into carbon and oxygen is an energy-consuming process compared to the catalytic converters. The best way to reduce CO₂ is to capture it from the source, store it and use it for industrial applications. To physically capture the CO₂ from the engine exhaust, adsorbents like molecular sieves are utilized. In comparison to other CO₂ separation methods, adsorption technique consumes less work and energy. Moreover, the sieves can be regenerated, reused and recycled once it is completely saturated. In this research work, zeolite X13 was chosen as a molecular sieve to adsorb CO₂ from the exhaust. A chamber was designed to store the zeolite and it is attached to the exhaust manifold. The selected engine was a single-cylinder Briggs and Stratton petrol engine. The experiments were conducted in two phases, the first phase to adsorb and the second phase to regenerate. Temperature pressure swing adsorption was chosen as the preferred process for the regeneration. This study was conducted by varying chamber length in three measurements and sieve quantities. The gas separated from the sieves during regeneration is tested using AVL Ditest analyser to study the percentage of CO₂ adsorbed from the engine exhaust. From the results, it was found that 70% of the CO₂ emissions were absorbed using low cost zeolite sieves.