title: Butter as a feedstock for biodiesel production.
abstract: Fatty acid methyl esters (FAME) were produced from cow's milk (Bostaurus) butter by esterification/transesterification in the presence of methanol. The product was assayed according to the Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels (ASTM D 6751). The preparation failed to meet the specifications for flash point, free and total glycerin contents, total sulfur, and oxidation stability. Failures to meet the flash point and free/total glycerin specifications were determined to be due to interference with standard assays for these parameters by short-chain-length fatty acid esters. The oxidation stability of the butterfat FAME was improved by supplementation with a commercial antioxidant formulation. Approximately 725 ppm of antioxidant was required to meet the ASTM-specified stability value for biodiesel. This work indicates that, without further purification to reduce a slightly excessive sulfur content, fatty acid ester preparations produced from butter are unacceptable as sole components of a biodiesel fuel. However, it is possible that even without further purification a butter-based ester preparation could be mixed with biodiesel from other feedstocks to produce a blend that meets the current quality standards for biodiesel. The results presented here also illustrate some potential weaknesses in the accepted methods for biodiesel characterization when employed in the analysis of FAME preparations containing mid- and short-chain fatty acid esters.
authors.affiliation: Fats, Oils and Animal Coproducts Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. michael.haas@ars.usda.gov
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Haas
authors.forename: Nadia
authors.initials: N
authors.lastname: Adawi
authors.forename: William W
authors.initials: WW
authors.lastname: Berry
authors.forename: Elaine
authors.initials: E
authors.lastname: Feldman
authors.forename: Stephen
authors.initials: S
authors.lastname: Kasprzyk
authors.forename: Brian
authors.initials: B
authors.lastname: Ratigan
authors.forename: Karen
authors.initials: K
authors.lastname: Scott
authors.forename: Emily Bockian
authors.initials: EB
authors.lastname: Landsburg
mesh_terms: D000818:Animals; D056804:Biofuels / Q000032:analysis*; D002079:Butter / Q000032:analysis*; D002417:Cattle; D003246:Conservation of Energy Resources / Q000379:methods*; D004951:Esterification; D010084:Oxidation-Reduction
chemical_list: D056804:Biofuels; D002079:Butter