Prediction of the emission characteristics of biogas as a supplementary fuel in SI engines using CFD to assess its applicability

Abstract

This study investigates the potential for the utilization of biogas as a supplementary fuel in a SI engine by studying the emission characteristics of a biogas-fuelled engine using computational fluid dynamics(CFD). Biogas is generated using a lab-scale floating drum bio digestor coupled to a SI engine to produce power. To determine the emission characteristics, the bio-digester and the combustion chamber of the SI engine with the desired specifications are modelled using the CREO software, and further Computational analysis is carried out using ANSYS FLUENT software. Emission parameters like Carbon monoxide (CO), Carbon dioxide (CO2), and Nitrous oxide (NOx) have been simulated for the SI engine utilizing biogas and gasoline. Computational results show that the bio-gas-operated SI engine shows less emission than gasoline. The results show that the CO emission decreased from 0.004 ppm to 0.035 ppm in gasoline and biogas modes, respectively. Also, the CO2 decreased from 0.021 ppm to 0.0052 ppm. The concentration of nitrous oxides in the emission shows a drastic decrease from 0.1343 ppm to 0.0234 ppm in gasoline and biogas mode. The significant reduction in emission characteristics when utilizing biogas as a fuel in SI engines against gasoline makes biogas an appealing fuel option for IC engines. applications.