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.

Bias and Imprecision in the Determination of Free Glycerin in Biodiesel: The Unexpected Role of Limitations in Solubility

“…Other possible contributions from the analytical protocol itself are: improper preparation or aging of calibration and internal standards; diminished and overburdened capacity of MSTFA; chromatographic peak tailing, column aging; inadvertent exposures of standards to moisture; and occasional peak overlaps. An example of the latter, caused by C10 methyl esters derived from C10 containing feedstocks [27], such as butter, is mentioned by Haas et al [28]. Another possible source of changing FG levels is the hydrolysis or transesterification of monoglycerides.…”

Retracted: Partial purification and characterization of lipase from locally produced edible oil‐seeds and its relevance in industries

“…The maximum level of acid value for biodiesel, as specified in American Society of Testing and Materials (ASTM) standard D6751 is 0.8 mg/g. 22 The acid value of biodiesel obtained from SN5 and MN5 lipase were 0.8 and 0.5 mg/g, respectively, which were either the same or close to standard values (0.8 mg/g) whereas the acid value of biodiesel from BN5 was greater than the standard value (1.08 mg/g). The FFAs content obtained from SN5, BN5, and MN5 because of transesterification of vegetable oil were 0.68, 0.9, and 0.36%, respectively.…”

“…Fuel that has been oxidized after long‐term storage will probably have a higher acid value (April 3, 2019 By Farm‐Energy Biodiesel Fuel Quality). The maximum level of acid value for biodiesel, as specified in American Society of Testing and Materials (ASTM) standard D6751 is 0.8 mg/g 22 . The acid value of biodiesel obtained from SN5 and MN5 lipase were 0.8 and 0.5 mg/g, respectively, which were either the same or close to standard values (0.8 mg/g) whereas the acid value of biodiesel from BN5 was greater than the standard value (1.08 mg/g).…”

Impacts of antioxidants on stability of biodiesel derived from waste frying oil

“…BioExtend 30, a commercial AO, advertised as having superior performance at low concentrations, can be used to revitalize oxidized biodiesel 6 . However, there are only limited studies on its effectiveness 7,8 . Using a modified ASTM D525 method, 9 this study investigates the impacts of BioExtend 30 concentration on the stability and properties of B100 produced from waste frying oil (WFO).…”