Biodiesel production by in situ transesterification

Abstract

Biodiesel is conventionally produced by transesterification of vegetable oils using an alcohol (usually methanol) and a catalyst (usually hydroxides or methoxides of sodium or potassium). The process usually uses pre-extracted oil as the raw material, which is usually produced by pressing the oil-bearing seeds, often followed by solvent extraction to extract any remaining oil. Alternatively, biodiesel can be produced via ‘in situ transesterification’ or ‘reactive extraction’. In this process, oil-bearing seeds are ground, then reacted directly with the alcohol and catalyst, thereby eliminating the need for pre-extracted oil, and its associated capital and intensive running cost production methods. Various parameters play important roles in determining the conversion, reaction rate and quality of the biodiesel in in situ transesterification. These include: catalyst type, seed moisture content, agitation intensity, molar ratio of alcohol to oil, reaction temperature, catalyst concentration, seed fragment particle size and alcohol type. This article gives an overview of in situ transesterification, the parameters that have a significant effect on this process and the advantages and disadvantages of this process.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.