Esterification of fatty acids from waste cooking oil to biodiesel over a sulfonated resin/PVA composite

Zhang, Honglei; Gao, Jiarui; Zhao, Zengdian; Chen, George Zheng; Wu, Tao; He, Feng

Abstract

Sulfonated cation exchange resins (s-CERs) have been widely studied as a replacement of liquid acids for the catalysis of esterification of free fatty acids (FFAs) to produce biodiesel with water as the only by-product. However, the water produced has strong affinity to sulfonate groups in s-CERs, which block the reactive sites for esterification and thus reduce the activity of a catalyst. To overcome this technical barrier, we have designed an s-CER/PVA composite by incorporating s-CER fines within a poly(vinyl alcohol) (PVA) matrix. PVA has a much stronger absorption preference for water than s-CERs and has very low selectivity for reactants (FFAs and methanol), which enables continuous removal of the produced water and liberation of reactive sulfonate sites in s-CERs for catalysis. With s-CER/PVA, FFA conversion was increased from 80.1% to 97.5% after an 8-hour reaction and the turnover frequency (TOF) was increased more than 3.3 times. The TOF of s-CER/PVA was also 2.6 times higher than that of sulfuric acid, suggesting that water-less, heterogeneous sulfonate sites are more reactive than water-blocked homogeneous ones. The reusability of s-CER/PVA was also enhanced due to the fact that the produced water that could cause deactivation of the s-CERs was largely removed by PVA.

Citation

Zhang, H., Gao, J., Zhao, Z., Chen, G. Z., Wu, T., & He, F. (in press). Esterification of fatty acids from waste cooking oil to biodiesel over a sulfonated resin/PVA composite. Catalysis Science and Technology, 2016(6), https://doi.org/10.1039/C5CY02133B

• Journal Article Type: Article
• Acceptance Date: Apr 4, 2016
• Online Publication Date: Apr 5, 2016
• Deposit Date: Jun 5, 2016
• Publicly Available Date: Jun 5, 2016
• Journal: Catalysis Science and Technology
• Print ISSN: 2044-4753
• Electronic ISSN: 2044-4761
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 2016
• Issue: 6
• DOI: https://doi.org/10.1039/C5CY02133B
• Public URL: https://nottingham-repository.worktribe.com/output/786512
• Publisher URL: http://pubs.rsc.org/en/Content/ArticleLanding/2016/CY/C5CY02133B#!divAbstract
• Contract Date: Jun 5, 2016