Direct Biodiesel Production from Harvested Microalgae Via in Situ Transesterification Using Hydrochloric Acid

This work presented in situ transesterification that is a combined process of lipid extraction and transesterification reaction using a homogeneous catalyst of hydrochloric acid (HCl) from wet microalgae. In situ transesterification was performed by heating the mixture of wet algal cells, HCl, methanol, and solvent in a single pot, leading to the yield of biodiesel, fatty acid methyl ester (FAME), over 90 % at 95 ^oC. The effects of reaction variables such as reaction temperature, amounts of catalyst, reactant, and solvent, and type of solvents on the yield were investigated. Using HCl as a catalyst for in situ transesterification is more beneficial than using H₂SO₄ because the FAME yield is less affected by moisture contents even higher than 80 %, and less amounts of catalyst and solvent are required in the HCl case. For the same molar amount of the two catalysts, HCl showed 15 wt. % higher FAME yield than H₂SO₄. This talk will show various sensitivity results of in-situ transesterification to produce biodiesel directly from wet microalgae using HCl as a catalyst.