The assessment of fusel oil in a compression-ignition engine in the perspective of the waste to energy concept: investigation of the performance, emissions, and combustion characteristics

Abstract

Fusel oil can be obtained from all agricultural products containing sugar, as well as from starchy products such as corn and potatoes, and from cellulosic products such as sulfite liquor, which is a wood and paper mill residue. Fusel oil is produced as a waste product during the production of bioethyl alcohol or biomethyl alcohol from sugar beet pulp remaining during sugar production in Turkey. In this study, alternative fuel blends prepared by infusing 5, 10, 15, and 20% of fusel oil to diesel (DF) by volume were tested in a single-cylinder, diesel engine at 1500 rpm and different loads, and thus, engine performance, pollutant emissions, and combustion characteristics were determined and compared with reference diesel. As a result, since fusel oil has lower calorific values than diesel, alcohol fuel blends caused a decrease in brake thermal efficiency (BTE) and an increase in brake specific fuel consumption (BSFC). It was observed that carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOX), and smoke emissions decreased significantly with addition of FUSEL oil to diesel while carbon dioxide (CO2) and oxygen (O2) emissions, which are an indicator of complete combustion, increased. This occurred since oxygen molecules in chemical structure of fusel oil improved emissions. Concerning combustion characteristics, it was observed that addition of fusel oil to baseline diesel generally increased in figures of in-cylinder pressure and net heat release rate. Moreover, it was determined that alcohol fuel blends generally increased ignition delay time compared to diesel due to their low cetane numbers. When all experimental results are evaluated, it can be said that fusel oil additive significantly reduces exhaust emissions without considerably affecting combustion and performance characteristics.