title: Glycerin esterification of scum derived free fatty acids for biodiesel production.
abstract: Scum is an oily waste stream of the wastewater treatment process that can be used to produce biodiesel. Combining acid hydrolysis and solvent extraction, a free fatty acid and acyl-glycerol rich product was produced. Free fatty acids (FFAs) present were converted to acyl-glycols via a high temperature (238°C) glycerin esterification process known as glycerolysis. The inorganic catalysts zinc aluminum oxide and sodium sulfate were tested during glycerolysis to compare the reaction kinetics of converting FFA to acyl-glycerols. It was concluded that the zinc-based catalyst increased the reaction rate significantly, from a "k" value of 2.57 (uncatalyzed) to 5.63, completing the reaction in 60min, half the time it took the uncatalyzed reaction (120min). Sodium sulfate's presence however slowed the reaction, resulting in a "k" value of 1.45, completing the reaction in 180min. Use of the external catalyst Zn-Al2O3 showed the greatest catalytic potential, but also assumes additional costs.
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Erik
authors.initials: E
authors.lastname: Anderson
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Addy
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Qinglong
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Huan
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Yuhuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Nonso
authors.initials: N
authors.lastname: Onuma
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Chen
authors.affiliation: Department of Bioproducts and Biosystems Engineering, and Center for Biorefining, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA. Electronic address: ruanx001@umn.edu.
authors.forename: Roger
authors.initials: R
authors.lastname: Ruan
mesh_terms: D056804:Biofuels; D002384:Catalysis; D004951:Esterification; D005230:Fatty Acids, Nonesterified / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D006868:Hydrolysis; D013431:Sulfates / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D056804:Biofuels; D005230:Fatty Acids, Nonesterified; D005990:Glycerol; D013431:Sulfates; D013455:Sulfur; D062065:Wastewater; D015032:Zinc; C012036:sodium sulfate
keywords: Biodiesel; Glycerolysis; Scum; Solvent extraction; Wastewater treatment