Biodiesel synthesis in DBD plasma reactor using triglyceride-methanol mixture contacted with CO2-steam gas mixture

Abstract

The conventional method of biodiesel synthesis is known to have a few drawbacks. With the intent of reversing the drawbacks, a research on biodiesel synthesis from triglycerides and methanol using cold plasma Dielectric Barrier Discharge (DBD) reactors was conducted by using two types of plasma carrier gas, namely argon (Ar) and a mixture of Ar + CO2 + H2O (vapor) by varying the temperature and reaction time systematically. The major products obtained from the cold plasma dielectric barrier discharge (DBD) reactor consists of four primary components: FAME (fatty acid methyl ester) or biodiesel, alkane (paraffin) and fatty alcohol and/or other side products which were analysed using GC-MS and FT-IR. The analysis was carried out mainly to determine the chemical conversion associated with reactant or biodiesel products. The types of triglycerides used in this research are (a). used cooking oil, (b). used mixtures of used palm oil and fresh palm oil, and (c). used mixtures of used palm oil and fresh castor oil. With the synthesis time for 2 hours, it was found that the cold plasma DBD reactor was able to change about 47- 89 % mixture of triglycerides (without catalyst and excess methanol) to various product such as FAME, greendiesel paraffin and fatty alcohols. It seems the uses of Argon Gas produce a 23.7% higher yield of FAME and paraffin than the mixture of argon and CO2.