DOI: https://doi.org/10.55373/mjchem.v26i6.81

Keywords: FAME; direct transesterification (in-situ); Spirulina Sp.; microalgae; acid catalyst, heptyl methyl methylphosphonate

Abstract

The depletion of petroleum-based fuels has led researchers to explore alternative biofuels. Microalgae are a potential alternative for biodiesel feedstock due to its cost-effective cultivation, low carbon emissions, and high biomass. As a third-generation feedstock, microalgae have become an attractive option to the energy field. This study investigated direct transesterification using microalgae and characterized the fatty acid methyl ester (FAME) produced by this method. An acid catalyst was chosen to prevent saponification which could promote the loss of products. The research methodology encompassed four main stages: microalgae cultivation, direct transesterification, biodiesel purification, and analysis of biodiesel components using gas chromatography and NMR spectroscopy. Sulfuric acid (5 % v/v) was used to acidify ethanol for direct transesterification of microalgae cells with a solids loading of 20 % (w/w). The collected FAME was characterised as heptyl methyl methylphosphonate (HMMP). The IUPAC name of this methyl ester was 1-[methoxy(methyl)phosphoryl]oxyheptane and its molecular formula was C9H21O3P. HMMP is a component in biodiesel production.