PETG Mesochannel Reactor for Efficient Biodiesel Synthesis using Microwave Heating

Abstract

The depletion of fossil fuels, harmful emissions from their combustion, and the 2022 global energy shock due to geopolitical instabilities have led to the surge in renewable energy development. Within the context of the transportation sector, biodiesel is a sustainable and green source of liquid biofuel that can replace petroleum diesel and simultaneously be part of a solution to the aforementioned global problems. Conventional biodiesel production suffers from poor mass transfer, which leads to slow reaction kinetics, lengthy reaction time and inefficient heating of reaction. This study aims to enhance the mass transfer of biodiesel production through microwave heating in combination with a mesochannel reactor, fabricated using polyethylene terephthalate glycol (PETG). A full factorial experimental study was investigated using palm oil with sodium hydroxide as catalyst, incorporating test parameters of methanol to oil molar ratio (3:1, 6:1, 9:1), catalyst loading (0.6, 0.8, 1.0 wt%) and reaction temperature (50, 60, 70 °C). Biodiesel samples were characterised using gas chromatography to quantify the biodiesel yield. The highest biodiesel yield of 78.0 % was achieved in under 1 minute at a methanol to oil molar ratio, reaction temperature and catalyst loading of 3:1, 70 °C and 1.0 wt%, respectively. It is postulated that greater yield could be achieved by lengthening the reactor channels. Overall, the use of PETG mesochannel reactor in combination with microwave-assisted heating has the prospect of facilitating rapid biodiesel production with enhanced mass transfer between reactants.