Indian Journal of Science and Technology

Abstract

Objectives: Performance and emissions of internal combustion (spark ignition) engine generator is investigated using the representative biogas composition from an anaerobic co-digestion mixture of various agricultural biomass wastes present in Mindanao, Philippines such as rice hull, coconut shell, cow manure as feedstock. Methods: The gases from the representative biogas composition are then fed to the 30kW engine generator and investigated the power generated, and its exhaust emissions. Findings: Results indicated that the variation of energy generated can be related to the electrical power produced from the engine unit to power the electrical appliances used at the same flow rate and pressure. At 1.4 kW electrical load and heating value of the purified biogas as 50 MJ kg-1, the consumption of biogas was observed to be the same. The engine also showed comparable efficiency ranging from 6.26% to 7.00% at 1.4 kW load. Further, the CO2 emission is observed to be 5.40% and amount of other emission pollutants are extremely few (nearly zero) using the representative biogas fuel in the engine. Thus, biogas fuel can be used directly as fuel in the spark ignition engine. Application: The biogas fuel can be used to other engines, but it requires some minor engine modifications in order to correct the compression ratio, spark ignition timing due to the slower flame speed of biogas fuel.

Keywords: Biofuels, Biogas, Biomass, Engine Emissions, Engine Performance