Production of alkyl ester as biodiesel from fractionated lard and restaurant grease

• Published in: Journal of the American Oil Chemists' Society 2002-02, Vol.79 (2), p.191-195
• Main Authors: Lee, Ki‐Teak, Foglia, Thomas A., Chang, Kyu‐Seob
• Format: Article
• Language: English
• Subjects: Alkyl ester; Bioconversions. Hemisynthesis; biodiesel; Biological and medical sciences; Biotechnology; Food industries; fractionation; Fundamental and applied biological sciences. Psychology; grease; lard; Methods. Procedures. Technologies; Use and upgrading of agricultural and food by-products. Biotechnology
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-002-0457-y

Methyl or ethyl esters were produced from lard and restaurant grease by lipase‐ or base‐catalyzed reactions. Before esterifying, some renewable substrates (lard and restaurant grease) should be manipulated through acetone fractionation or on a chromatography column packed with an adsorbent to obtain maximal reaction rate. Because lipase activity was hindered by excess amounts (more than 1 mol) of methanol, each 1 M methanol was added sequentially after 24 h of reaction. Through a three‐step reaction, 74% conversion to tallow‐methyl ester was obtained. However, a porous substance, such as silica gel, improved the conversion when more than 1 M methanol was used as reaction substrate. When a 1∶3 (fractionated lard/methanol, mole ratio) substrate was used, the conversion rates (i.e., extent of conversion) were 2.7 (24 h) and 2.8% (48 h). However, with 10% silica gel in the reaction mixture, the conversion rates increased to 25 and 58%, respectively. Regenerated restaurant grease (FFA removed through column chromatography) was further converted to esters by alkali‐catalyzed methanolysis. After 24 h of reaction, 96% conversion was obtained, while only 25% conversion was observed from crude grease. Alkyl esters produced in this study could be used for fuels, potentially as biodiesel.