Rapid conversion of fat, oil and grease (FOG) into biodiesel without pre-treatment of FOG

Abstract

In this study, the conversion of fat, oil and grease (FOG) into fatty acid methyl esters (FAMEs) without pre-treatment of FOG is investigated. A thermally induced process to accomplish simultaneous esterification of free fatty acids (FFAs) and transesterification of lipids is introduced. Despite high contents of impurities in FOG (similar to 14 wt%), the maximum achievable yield of FAMEs on feedstock mass basis was >86% for 10 s reaction time without removal of impurities prior to the reaction while conventional acid catalyzed reaction only produced <27.7% FAMEs from FOG. This means that the introduced technique can be effective for the conversion of low-quality raw material (e.g., FOG) into biodiesel. This study would suggest the potential not only for developing a sustainable integrated treatment process of FOG requiring no separation of lipids and FFAs in wastewater treatment facilities but also for using FOG as a renewable energy resource.