Effectiveness Of Ultrafiltration On The Recovery And Reuse Of Liquid Enzymes In The Production Of Biodiesel

This research evaluated the use of enzyme catalysts in the production of biodiesel. Traditionally, biodiesel production uses a base or acid catalyst to convert triglycerides (TG) and free fatty acids (FFA) into fatty acid methyl esters (FAME) or biodiesel. Enzyme catalysts have the potential to offer environmental and economic advantages by utilizing lower quality feedstocks, producing a higher value glycerol co-product, and being a more energy efficient process. For enzymes to be economically advantageous they must be recovered and reused for multiple batches. Two enzyme recovery techniques of a simple settling method versus ultrafiltration were compared. Pilot-scale runs were completed where each run used a single, initial dose of enzymes to catalyze four batches. The runs compared recovery methods, where the effectiveness of enzyme reuse was determined by the percent conversion of TG and FFA to FAME as the enzyme continued to be reused. Gas chromatography was used to determine the amount of TGs consumed throughout each batch. While both techniques resulted in loss of enzymes, the loss in activity was 47% using filtration compared to 73% without. Although findings are preliminary, this study shows promise for ultrafiltration to provide cost savings through better enzyme recovery and reduced production time.