Esterification of fatty acids from waste cooking oil to biodiesel over a sulfonated resin/PVA composite. Issue 14 (19th April 2016)

• Record Type: Journal Article
• Authors: Zhang, Honglei; Gao, Jiarui; Zhao, Zengdian; Chen, George Z.; Wu, Tao; He, Feng
• Is Part Of: Catalysis science & technology. Volume 6:Issue 14(2016)
• Page Start: 5590
• Page End: 5598
• Publication Date: 2016-04-19
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c5cy02133b
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : PVA enhances the catalytic activity and reusability of s-CER/PVA for esterification by absorbing the water produced and liberating reactive –SO3 H sites. 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.