Conversion of Used Cooking Oil into Biodiesel Using Lignite Coal Catalyst with the Assistance of Chemical Ultrasonography

Repeated use of cooking oil can produce used cooking oil or waste that can hurt consumers and have a negative impact on the environment. Therefore, to overcome this, a study was conducted to convert used cooking oil into biodiesel using low-grade coal catalysts with the help of ultrasonic waves. The purpose of this study was to determine the quality of biodiesel produced from the conversion of used cooking oil using low-grade coal catalysts with the help of ultrasonic waves. Biodiesel was obtained by reacting oil: methanol (1: 3) with a transesterification process for 35 minutes with temperature variations of 40, 45, 50, 55, and 60℃ by adding 6 grams of low-grade coal catalyst with the help of ultrasonic waves that have a frequency of 40kHz. The results of this study obtained biodiesel with the highest yield of 91.38% at a temperature variation of 50℃ with characteristics of a density of 40℃ of 877.2 kg/m3, a kinematic viscosity of 40℃ of 5.35 cSt, a water content of 0.040% and an acid number of 0.45 mg KOH/g and a meth ester content of 99.36%. In general, the biodiesel produced has met SNI 7182:2015.