Effect of load on the performance of a family scale biogas-fuelled electricity generator

Abstract

Abstract Biogas is a renewable fuel that can be used for many applications, such as fuel for kitchen stove, heating and drying system, electricity generation engine, and fuel to run farm tractor. The biogas used in this research was produced from tapioca wastewater treatment equipped with covered lagoon digester. Gasoline generator set having rated capacity 2500-W was modified in such a way that is able to run with 100% biogas. The experiment was performed by running generator set at different loads with incremental of 100-W. Three replications were conducted to get the average values. Performance parameters to be evaluated include biogas consumption, speed of engine (RPM), output power, and thermal efficiency. Results showed that generator set is able to work with raw biogas with methane content of 53%. The generator set reached a maximum load of 1300 W (52% of rated capacity). Biogas consumption increased with load from 1.40 kg·h−1 (no load) to 2.56 kg·h−1 at a load of 1300-W. Biogas specific consumption decreased with load from 16.4 g·W−1·h−1 at load 100 W to 2.2 g·W−1·h−1 at load 1300 W. Output power also increased with load from 0.04 to 0.49 ampere, respectively at a load od 100-W and 1300-W. Engine speed, on the other hand, decreased with load from 3686 RPM (no load) to 2413 RPM (load 1300-W). With biogas methane content of 53%, the maximum thermal efficiency of the generator set was calculated to be 11%.