Application of deep eutectic solvents as catalysts for the esterification of oleic acid with glycerol

Scott T. Williamson, Kaveh Shahbaz, Farouq S. Mjalli, Inas M. AlNashef and Mohammed M. Farid

Renewable Energy, 2017, vol. 114, issue PB, 480-488

Abstract: Free fatty acids (FFA) in low grade oil could be reduced by using an esterification reaction with glycerol, which itself is a waste product of biodiesel synthesis to give mono- and di-glycerides. This study investigated, for the first time, the reaction between oleic acid as a FFA with glycerol, using a phosphonium-based deep eutectic solvent (DES) as a catalyst. The effects of temperature (120 °C, 150 °C and 180 °C) and the DES catalyst concentration (1, 3 and 5 wt%) on the esterification efficiency of fatty acid conversion were observed. The glycerol to fatty acid molar ratio (6:1) and agitation speed (600 rpm) were kept constant. The results revealed that the lowest activation energy of 54.64 kJ/mol was attained using 5 wt% of DES catalyst. Accordingly, optimum reaction conditions were found at a temperature of 150 °C with a 5 wt% DES catalyst, which produced 95% FFA conversion after 30 min of reaction time. In addition, 85% of combined mono- and di-glycerides was observed at the optimum condition, which will be easier to transesterify using alcohol. The process was repeated without adding any fresh catalyst and results showed that catalyst activity sustained very well, suggesting that it can be reused a number of times.

Keywords: Biodiesel; Deep eutectic solvent; Esterification; Free fatty acids; Glycerol; Catalyst (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0960148117306614
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:renene:v:114:y:2017:i:pb:p:480-488

DOI: 10.1016/j.renene.2017.07.046

Access Statistics for this article

Renewable Energy is currently edited by Soteris A. Kalogirou and Paul Christodoulides

More articles in Renewable Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().