The Use of Biogas in Internal Combustion Engines: A Review

Biogas derived from organic waste materials is a promising alternative and renewable gaseous fuel for internal combustion (IC) engines and could substitute for conventional fossil fuels. The aims of this study are to review the past researches on biogas fuelled IC engines and from this review, to identify current research needs. A detailed analysis of the previous results of biogas fueling on the emissions and performance of spark ignition (SI) and dual fuel compression ignition (CI) engines is presented. The literature review reveals that the published research on biogas fueled IC engines are not rich in number and the scenario of biogas-diesel dual fuel engines is even worse. According to the analysis, biogas fueling in IC engines causes lower power output compared to natural gas, irrespective of the engine operating conditions. However, the use of biogas allows exhaust nitrogen oxides (NOx) emissions to be reduced substantially. Both experimental and computational analyses have been done in the case of SI engines. However, there are needs to investigate the exhaust emissions for the biogas-diesel dual fuel engines both experimentally and computationally. Also the effect of H₂S on engine emissions and life/durability, which is neglected very often in the literature, needs to be investigated.