Modelling of the Operation of a Small Generator Set Powered by Scrubbed Biogas from Cow Dung

Abstract

This study involved investigation of the impact of the various factors affecting the use of biogas in a modified gasoline generator. A 1.5 kW gasoline generator was modified to function with biogas by advancing the engine timing and installing a Bernoulli suction device in the carburetor. Biogas produced was purified by removing carbon dioxide, hydrogen sulphide and water vapor in this sequence before introduction into the engine of the generator. Various factors associated with engine performance were investigated including, biogas fuel consumption rate, maximum power output, NOx emissions, CO emissions and the overall efficiency. Results indicated a biogas fuel consumption of 6 litres per minute or 3.6 m 3 per hour. The maximum power output was 0.91 kW giving a power drop of about 39%/ The maximum overall efficiency of the biogas fuelled generator set was 15%. NOx and CO emissions were 742 and 30 ppm respectively.