Uji Performansi Mesin Diesel Stasioner Menggunakan Biodiesel Ampas Kopi pada Konsentrasi B15, B25, dan B35 dengan Variasi Beban

Abstract

The increase in fuel consumption in recent years, along with population growth and the development of the transportation and industrial sectors, has led to a reduction in fossil fuel reserves and an increase in greenhouse gas emissions. Therefore, environmentally friendly and sustainable alternative fuels are needed. One reliable alternative fuel is biodiesel. Coffee grounds are one raw material that can be utilized to produce biodiesel. Coffee grounds still contain lipid sources ranging from 15% to 20% of their initial weight through extraction and transesterification processes. This study aims to analyze the performance test results of a stationary diesel engine using a mixture of coffee grounds biodiesel (WCGB) and pure diesel fuel. The comparisons include pure diesel fuel at 100%, diesel fuel at 85% + WCGB at 15%, diesel fuel at 75% + WCGB at 25%, and diesel fuel at 65% + WCGB at 35%. The engine was operated at a constant speed of 2500 rpm and varying loads of 1500 g, 2500 g, 3500 g, and 4500 g. The results showed that the best performance of the diesel engine was achieved using 65% diesel fuel + 35% WCGB compared to pure diesel fuel, with increases in torque, power, and thermal efficiency of 13.25%, 13.25%, and 15.62%, respectively. There was also a decrease in specific fuel consumption of 15.62%. The best reduction in exhaust gas emissions was achieved using a fuel blend of 75% pure diesel fuel + 25% WCGB.