Combustion Analysis of Biodiesel Blends on Pressure, Temperature, and Heat Release at Engine Loads

Abstract

This study analyzed the combustion performance of various biodiesel blends on in-cylinder pressure, in-cylinder temperature, and Rate of Heat Release (ROHR) in a diesel engine with 25% and 50% loads. The tested fuel blends included pure diesel (DB100), and biodiesel blends with 10%, 20%, and 30% biodiesel content (F10B10, F20B10, F20B20, and F30B10). The results showed that in-cylinder pressure increased with increasing load, where the peak pressure on DB100 reached 63 bar at 25% load and increased to 65 bar at 50% load. Meanwhile, the F30B10 blend experienced a slight decrease in pressure, with a peak value of 61 bar at 50% load, indicating slower combustion characteristics. Regarding in-cylinder temperature, DB100 has the highest peak temperature of 1250 K at 25% load and 1380 K at 50%. Biodiesel blends with higher proportions, such as F30B10, have lower temperatures, namely 1180 K at 25% load and 1250 K at 50% load. ROHR analysis shows that at 50% load, the F20B20 blend has the highest ROHR, reaching 45,000 kW, compared to 42,000 kW for DB100. These results indicate that biodiesel can maintain good combustion performance despite experiencing a slight decrease in pressure and peak temperature. Thus, biodiesel blends can be an alternative fuel that has the potential to reduce dependence on conventional diesel without sacrificing engine performance significantly.