Lipase immobilized carbon nanotubes for conversion of Jatropha oil to fatty acid methyl esters

Abstract

Lipase has been immobilized on multi-walled carbon nanotubes (MWCNTs) through the reaction of the carboxylated nanotubes with the enzyme in the presence of N-hydroxysulfosuccinimide (NHS) and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride. Successful immobilization has been verified by infrared spectroscopy and scanning electron microscopy. The synthesized biomaterial has been used for catalyzing the conversion of Jatropha oil to the fatty acid methyl esters (FAME). Progress of the conversion reaction has been monitored with NIR spectroscopy. Gas chromatographic studies have indicated that the use of lipase–MWCNT bioconjuagate leads to almost quantitative conversion of Jatropha oil to the FAME. Around 1 h of the reaction, in the presence of around 15% of catalyst (mass fraction of catalyst on the total mixture), has yielded the desired results. The above used catalyst support has been regenerated 10 times without any adverse effect on the enzyme activity.