Production of alkyl esters from tallow and grease using lipase immobilized in a phyllosilicate sol-gel

The lipase-catalyzed synthesis of alkyl esters from tallow and grease using Pseudomonas cepacia lipase (PS-30) immobilized within a phyllosilicate sol-gel matrix was investigated. The effects of the presence of alcohol and of the amount of enzyme used were studied. The matrix-immobilized PS-30 lipase effectively converted grease and tallow to ethyl esters in greater than 95% yield when using ethanol. The final conversion of grease or tallow to alkyl esters was aided by the addition of molecular sieves (0.4 wt% of substrates) to the reaction mixture. The matrix-immobilized PS-30 enzyme was easily recovered and could be reused at least five limes without losing its activity. Accordingly, the phyllosilicate sol-gel immobilized PS-30 lipase is potentially useful for the economic production of biodiesel fuel.