Renewable Energy Test - Biogas As Fuel In Otto Cycle

Abstract

The use of renewable energy such as biogas is a must to support the achievement of the targets that have been echoed through the go green campaign, namely public awareness of the clean air environment. The power of the otto cycle combustion engine is highly dependent on the conversion and heat of combustion (% CH4 in biogas) as well as the stoichiometric fuel-air ratio requirements. A performance test of the otto cycle motor fueled with biogas with various methane contents has been carried out. It was found that biogas with 95% CH4 at 3000 rpm produces the highest power of 3.906 kW, compared to the power of gasoline, but with a 4.8% decrease in power. Meanwhile, the average power produced from biogas with 55% CH4 content is 2,296 kW. The average torque of the biogas engine (95% CH4) is 7,609 (N.m) and the highest is 9,014 (N.m), but still 24% lower than the gasoline engine. The most efficient operation of the engine fueled with biogas was observed at 1,831 L/h biogas consumption as opposed to 1.4 L/h when the engines was run using gasoline. In other words, a lower % of CH4 was attained with a x% increase in fuel consumption. The average specific fuel consumption (SFC) of biogas (95% CH4) is 0.717 kg/kW.h, on the other hand, the gasoline engine is 0.395 kg/kW.h. The highest thermal efficiency of a biogas engine attained at maximum loading can match the efficiency of an ideal gasoline engine, which is close to 25%.