Synthesis of biolubricant by transesterification of palm kernel oil with simulated fusel oil: Batch and continuous processes

Simulated fusel oil containing a mixture of ethyl (11.2%), butyl (10.6%) and isoamyl alcohols (78.2%) was used to obtain lubricant esters from palm kernel oil by enzymatic route using lipase from Burkholderia cepacia immobilized on epoxy matrix silica-hydroxyethyl cellulose as a biocatalyst. Runs were performed under both batch and continuous mode to determine the influence of oil-to alcohol molar ratio on the ester concentrations using as a model isoamyl alcohol as acyl acceptor. The optimum oil to alcohol molar ratio was 1:4 and high isoamyl esters formation (99 wt%) was attained in 48 h (batch runs) and 8 h of space-time (continuous runs). Such conditions were used to perform the transesterification reactions from palm kernel oil with simulated fusel oil rendering similar results. The kinematic viscosities at 40 degrees C confirmed the high conversion by modifying the initial palm kernel oil viscosity from 30.13 mm(2)s(-1) to values ranging from 3 to 6 mm(2)s(-1). The viscosity index was 149.22 +/- 2.11 and the oxidative stability was 23.85 +/- 1.65 min. Also, the biocatalyst was found to be stable revealing half-life time (t(1/2)) of about 38 days.