Fatty acid esters are now being produced commercially with immobilized commercial lipases in non aqueous solvents. In this study waste thermocol a commercial lipase (Steapsin) was immobilized on waste thermocol (polystyrene used as packing material for chemicals) by adsorption with a binding efficiency of 28 % (0.16 IU/mg matrix). Its efficacy for esterification was checked by Gas liquid chromatography for the synthesis of methyl myristate. The thermocol– bound lipase was used to synthesize methyl myristate from myristic acid and methanol in dimethyl sulphoxide. The optimization of the reaction conditions such as biocatalyst loading, effect of reactant concentration, reaction time, temperature, molecular sieve and scale up was studied. The immobilized lipase (20 mg/ml) was used to perform an esterification in DMSO that resulted in synthesis of approximately 88 mM of methyl myristate at 45°C, under continuous shaking at (120 rpm) after 16 h when myristic acid and methanol was used in an equimolar ratio. The addition of molecular sieve (3Å x 1.5 mm) has deleterious effect. The bound lipase resulted in 48.8 mM ester in the 6th cycle of repetitive use of matrix. When the reaction volume was scaled up to 50 mL, the ester syntheisized was 31 mM under optimized conditions.
