title: Biodiesel production from high acid value waste frying oil catalyzed by superacid heteropolyacid.
abstract: Transesterification of waste cooking oil with high acid value and high water contents using heteropolyacid H3PW12O40 x 6H2O (PW12) as catalyst was investigated. The hexahydrate form of PW(12) was found to be the most promising catalyst which exhibited highest ester yield 87% for transesterification of waste cooking oil and ester yield 97% for esterification of long-chain palmitic acid, respectively. The PW12 acid catalyst shows higher activity under the optimized reaction conditions compared with conventional homogeneous catalyst sulfuric acid, and can easily be separated from the products by distillation of the excess methanol and can be reused more times. The most important feature of this catalyst is that the catalytic activity is not affected by the content of free fatty acids (FFAs) and the content of water in the waste cooking oil and the transesterification can occur at a lower temperature (65 degrees C), a lower methanol oil ratio (70:1) and be finished within a shorter time. The results illustrate that PW12 acid is an excellent water-tolerant and environmentally benign acid catalyst for production of biodiesel from waste cooking oil.
authors.affiliation: Key Laboratory of Polyoxometalate, Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, PR China.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Cao
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Fengying
authors.initials: F
authors.lastname: Zhai
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Jianghua
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Shengtian
authors.initials: S
authors.lastname: Wang
authors.forename: Weimin
authors.initials: W
authors.lastname: Zhu
mesh_terms: D000143:Acids / Q000737:chemistry*; D002384:Catalysis; D005742:Gasoline; D007220:Industrial Waste / Q000517:prevention & control*; D010938:Plant Oils / Q000737:chemistry*; D012147:Restaurants
chemical_list: D000143:Acids; D005742:Gasoline; D007220:Industrial Waste; D010938:Plant Oils