Effects of using acetylene-enriched biogas on performance and exhaust emissions of a dual fuel stationary diesel engine

Abstract

Biogas, which can be produced easily and cost effective from agricultural and animal waste, is an attractive alternative fuel to drive stationary diesel engine especially in rural areas. In this study, the effects of using acetylene enriched biogas under very lean mixture conditions in a four stroke, two cylinder, air-cooled diesel engine capable of developing 11.5 kW at 3000 rpm on performance and exhaust emissions were experimentally investigated. The experiments were carried out at 10 Nm, 20 Nm and 30 Nm torque. Acetylene flow rate of 2 slpm, biogas flow rate of 15 slpm and the engine speed of 1750 rpm were kept constant. The results showed that more than 36 % diesel substitution was possible with acetylene-enriched biogas at the specified flow rate without any degradation in normal operation. Moreover, the experimental findings revealed that the use of biogas and acetylene reduced brake thermal efficiency by 21.7 % and 5.8 % at 10 Nm and 20 Nm torque but only reduced by 0.6 % at 30 Nm torque. The exhaust gas temperature of dual fuel mode was found to be higher than the case of diesel mode especially at 20 and 30 Nm torque. While NO emission were lower, CO, and CO2 emission were higher in dual fuel mode compared to single diesel mode.