Development of Biogas Tractors (Part 1)

──Basic Performance in Terms of Engine Power, Torque, and Emission──

Abstract

Biogas is used in gas engine cogeneration to obtain electricity and heat. However, only the biogas produced is stored in the plant. Hence, we developed dual-fuel biogas tractors that can be operated with biogas and diesel. Their basic performance in the steady state was tested. The results of power take-off shaft (PTO) performance tests showed that tractor operation was stable at all engine speeds and under loads. The maximum engine torque and power in the dual-fuel model were higher than the conventional values by 10%. The maximum fuel replacement rate was 86%. NO_X and CO₂ emissions decreased by 8% and 11%, respectively, in the dual-fuel mode. However, CO and HC emissions increased because excess biogas prevented diesel fuel combustion.