Biogas production from waste banana leaves and its application in diesel engine

Diesel-powered heavy vehicles play a crucial role in economic growth but are strongly associated with fossil fuel consumption and inflation, pose significant challenges to sustainable development of any nation. Consequently, there is increasing global interest in generating renewable energy from organic waste. Anaerobic digestion (AD) is an effective method for producing biogas from biomass (dry waste banana leaves), which can be utilized in dual-fuel (DF) engines. However, the presence of carbon dioxide (CO 2 ), the second major constituent of biogas, adversely affects the combustion in diesel engines. To reduce CO 2 concentration, a scrubbing process using a 1 N sodium hydroxide (NaOH) solution was employed, which lowered the CO 2 concentration from 28.82% to 4.85% in the raw biogas and enhanced the methane content from 68.08% to 87.02%. In the present study, a diesel engine with thermal barrier coating (TBC) operating in DF mode was evaluated using biogas. Diesel blended with 5% diethyl ether (5DEE) by volume was used as pilot fuel to enhance the combustion attributes of DF engine. The prime goal is to evaluate the combined effect of TBC, which increases combustion temperature, and 5DEE as pilot fuel accelerates the rate of combustion that enabled the biogas energy share to reach a maximum of 53.1% at full engine load. In the DF engines with coating, the useful energy (in terms of brake power) increased to 23.72% and 24.77% for diesel and 5DEE respectively compared to 25.75% for base result (diesel alone operation) resulting in significant substitution of diesel by biogas.