Efficient lipase catalysed production of a lubricant and surfactant formulation using a continuous solvent-free process

Abstract

The transesterification of sunflower oil with a high oleic acid residue content (typically 83.5%) with butanol-1 by immobilised Lipozyme ® was carried out in a solvent free system and in a continuous way. During the first 6 h of reactor operation, a transition phase was observed, in which the main products were butyl ester and glycerol. This latter being insoluble in the reaction mixture, it is adsorbed onto the enzyme support thus leading to a decrease in enzyme performance. Step by step, less and less glycerol is produced and finally when glycerol is no longer produced a steady state is attained. The product composition is a mixture of butyl ester (65 molar%), monoglyceride (26 molar%), diglyceride (6 molar%) and residual triglyceride (3 molar%). This mixture has interesting lubricant and surfactant properties. The reactor was maintained without any loss in activity for a period of 3 months. This result is very different to that obtained using an organic solvent ( n-hexane) which leads to a total loss of enzyme activity within a few hours.