The Supercritical Biodiesel Production Process

Producing biodiesel from ethanol generated from agricultural biomass via fermentation is a renewable alternative to producing fossil-based methanol for biodiesel generation. This study has focused on the development of process intensification technologies to resolve some technical challenges facing biodiesel production, such as long residence times and catalyst sensitivity. These intensification technologies enhance process mass/heat transfer to achieve a continuous, scalable process that can be easily transported to utilize locally available feed stocks. The esterification and trans-esterification reactions of waste cooking oil (WCO) with high free fatty acids (FFA) were investigated. Also, an intensive study has been made to design and build a prototype laboratory-scale set up of supercritical alcohol. A prototype reactor setup was designed and used for continuous biodiesel production in the temperature and pressure range of 240 – 400 °C and 70 – 400 bar, respectively. A trace amount of the catalyst and the co-solvent have been used to increase the process yield. The response surface methodology was followed to optimize process parameters, and the process kinetics and thermodynamic parameters were also studied and calculated.

Keyword: Biodiesel, supercritical ethanol, CO₂ co-solvent, response surface methodology.