Enzymatic Synthesis of Castor oil hexyl ester in liquid carbon dioxide medium and its potential application as Biolubricant

CASTOR OIL HEXYL ESTER AS BIOLUBRICANT

Abstract

A novel green method for production of alkyls esters has been discussed in this paper. Liquid carbon dioxide (CO₂) can be used as reaction medium and having advantages of green solvent. Enzymatic esterification of castor oil has been carried at 1:3 stoichiometric amount of castor oil to alcohol in presence of immobilized lipase Lipozyme TL IM. The progress of the reaction has been monitored time to time and the maximum yield of 88.3% has been observed within 5 h for hexyl esters. In this process, liquid CO₂ has acted as solvent in the reaction system and has increased the mutual solubility between alcohol and castor oil. The produced hexyl esters have been evaluated for tribological properties.