Kajian Performansi Mesin dan Laju Korosi Biodiesel dari Campuran Minyak Goreng Bekas (WCO), Minyak Kesambi dan Minyak Solar

Abstract

Biodiesel from Used Cooking Oil has disadvantages, such as low oxidation stability during storage and poor cold flow properties. These poor physicochemical properties can be corrected in various ways, such as mixing with other non-edible oils. The purpose of this study was to synthesize a mixture of Waste Cooking Oil (WCO)- Schleichera oleosa with a ratio of 70:30 %, and the resulting biodiesel was then mixed with diesel oil to test engine performance, exhaust emissions and material compatibility. In this research, the WCOK30 crude oil synthesis process uses a double jacket reactor with a 2-step method (ester/transesterification). The WCOK30 crude oil mixture was then degummed by adding H3PO4 and processed for 30 minutes to remove the gums. The resulting degumming oil was then subjected to an ester process by adding 2% by weight H2SO4 catalyst at a temperature of 60oC. The esterification process was carried out for 1-2 hours, and the agitation speed: was 1,000 rpm. The transesterification process was carried out at 60 °C using a circulating heater. After that, potassium hydroxide (KOH) of (0.5,-2%) was dissolved in methanol, with a methanol-to-oil ratio of (8:1; 10:1 and 12:1), catalyst KOH-methanol solution was then added to the heated oil for 1-2 hours. The oil mixture was stirred constantly at (1,000 rpm). The results showed that the highest transesterification time was obtained at 60 minutes and produced the highest yield of 94%. The optimum condition is a catalyst concentration of 1 wt.% with a stirring speed of 1,000 rpm at 60 oC with a molar ratio of methanol to oil (12:1). It was found that there was an increase in oxidation stability in 106% WSME biodiesel (6.8 hours) while in WCO biodiesel (3.3 hours). The WSME biodiesel pours point decreased from 12 oC to 9 oC. Increasing the ratio of biodiesel in diesel up to B40 at engine speed up to (2,750 rpm) and a load of 1.5 N.m shows an effect on diesel engine performance. The Brake Power value decreased slightly while the Brake Specific Fuel Consumption (BSFC) value slightly increased by 7.7% and 16.67%, respectively. The Brake Thermal Efficiency (BTE) and MEP shows an increasing trend of 12.5% and 8.6%, respectively. Increasing the content of biodiesel in diesel fuel slightly increases NOX emissions by 25% but reduces the emission of CO, CO2 and smoke opacity by 50% and 131.25%, respectively. Furthermore, exposure to corrosion on metals that have been tested for static corrosion at ambient temperature shows a change in colour and the presence of corrosion on carbon steel and SS201. The corrosion rate of mild steel is higher than that of mild steel, but the corrosion rate is faster when the immersion time is 500 and continues to decrease until 2,000 hours of immersion in biodiesel (B10, B20, B30 and B40). The WSME biodiesel produced complies with ASTM D6751 standards.