ZrOCl2·8H2O:An Efifcient and Cheap Catalyst for Esteriifcation of Free Fatty Acids to Methyl Esters

The esteriifcation of lauric acid with methanol could be efifciently catalyzed by ZrOCl2·8H2O, and this reaction was studied to develop a green method for biodiesel production. The inlfuencing factors, such as amount of catalyst, reac-tion time and molar ratio of acid to methanol, were investigated. The results indicated that the ZrOCl2·8H2O catalyst showed high catalytic activity, and gave a 97.0%methyl laurate conversion rate under the following optimized conditions, viz.:a lauric acid/methanol molar ratio of 1:10, a catalyst dosage of 4%, and a reaction duration of 2 h at methanol relfuxing tem-perature. The catalyst could be easily recovered while its activity could be well retained after three cycles. The ZrOCl2·8H2O catalyst also exhibited excellent catalytic activity for the esteriifcation of different free long-chain fatty acids (including non-edible oils with high acid value) with different short carbon chain alcohols. Therefore, the ZrOCl2·8H2O catalyst has good potential for the synthesis of biodiesel from low-cost feedstocks such as waste vegetable oils and non-edible oils.