Selective esterification to produce microalgal biodiesel and enrich polyunsaturated fatty acid using zeolite as a catalyst

Abstract

Microalgae can be both a promising biofuel feedstock and a source of polyunsaturated fatty acids (PUFA). This paper reports a novel integrated process that simultaneously produces biodiesel and enriches PUFA. It was accomplished by using zeolite as a selective catalyst that preferentially converts shorter-chain fatty acids (SCFA) into fatty acid methyl esters (FAME) (86% conversion for S. limacinum and 65% conversion for N. salina) and enriches high-value PUFA (70% for S. limacinum and 78% for N. salina) in the unreacted free fatty acid (FFA) stream. The esterification reaction rate was affected by acid strength and pore size, while the selectivity of zeolite increased as pore size of zeolite decreased. This approach allows production of high quality biodiesel and efficient PUFA enrichment. The unreacted PUFA can be further refined for nutraceutical or other applications to improve economic viability of microalgal biodiesel production.

Esterification process catalyzed by ZSM-5 zeolite synthesized via modified hydrothermal method

“…The tube containing the OAME extract was centrifuged at 1500 g for 2 min and 1 μl of hexane phase was injected for GC analysis. Results are obtained from GC data and the conversion of OAME was calculated by the formula [ 7 ]: …”

APA-style human milk fat analogue from silkworm pupae oil: Enzymatic production and improving storage stability using alkyl caffeates

“…The structure of HMF must be simulated to manufacture human milk fat analogues (HMFAs) for better digestion. The steric configuration of fatty acid is determined by chain length and unsaturated degree 7 , and polyunsaturated fatty acids have higher steric hindrance. It was not clear if the polyunsaturated fatty acid could be served as feedstock in the lipase-catalyed HMF production.…”

Free fatty acids esterification catalyzed by acid Faujasite type zeolite

“…Faujasite zeolite has been studied as a catalyst for the esterication reaction. 41,48 The catalytic activity of the zeolites is not clearly related to the amount of active sites on the surface of the catalyst, but it is more dependent on the porosity and hydrophobic character of the materials. 41 3.2.4 Recyclability.…”