Biofuel esters produced in two-stage process

Research conducted at Tohoku University in Japan has uncovered a two-stage process capable of producing fatty acid esters for use in biofuel with a conversion rate of more than 98.6 per cent.

The findings are published in the latest issue of Energy & Fuels and looked at a continuous biofuel production technique using rice bran oil as a raw material.

Oil was first fed into an expanded-bed reactor for esterification of the free fatty acid contained within to occur using a cation-exchange resin catalyst.

Stage two of the process saw the resultant mixture fed directly into an anion-exchange resin catalyst phase to trigger transesterification of the triglyceride.

The researchers found no need for extra alcohol to be added, byproducts to be removed or for the oil to be dewaxed or degummed in order to achieve almost complete conversion from a solution of 14 weight per cent free fatty acid and alcohol.

Research at the Reaction Process Engineering Laboratory at Tohoku University, where report author Toshikuni Yonemoto is based, covers topics including centrifugal chromatography and the kinetics of microencapsulation.