Recovery Act - Utilization of Immobilized Lipase System for Waste Water Reduction in the Bioenergy Industry

Existing biodiesel production processes results in very low quality waste water which is high in fats, oils and greases and BOD (biological oxygen demand). This material is most often discharged to city sewer systems, causing problems in the pipes and at the waste water treatment plants themselves. Furthermore, crude biodiesel glycerin, a co-product of the process, has little or negative value, causing some producers to offload it at a loss or even worse into streams, lakes, or sewers. By developing an enzymatic biodiesel production method the washing step, and the wastewater, in the production process can be eliminated. The current biodiesel production methodology forms soaps or salts in both the biodiesel and glycerin phases, which would be eliminated using enzymes. During Phase I a method was developed which consistently produces ASTM quality biodiesel using virgin soy, yellow grease, and brown grease. In addition, as of the writing of this summary, a 15 day life cycle trial showed no significant loss in enzyme activity. Phase II will continue enzyme life trials and process optimization and build and test a 500 gallon per day full scale pilot unit. Commercial Applications and Other Benefits: As this project progresses to and beyond Phase III, biodiesel plants utilizing this process will eliminate their wastewater sidestreams, reducing cost and stress on local waste water treatment plants. Greater demand on brown grease will spur more local trap grease collectors to begin removing this valuable energy stream from our waste and reduce costly illegal discharges of trap grease. The technical grade glycerin produced will increase profitability and availability of glycerin for use in bio-based products. Finally, as the US ramps up alternative fuel use through the RFS II mandate, biodiesel producers must return to full capacity and find new feedstocks to feed the demand. Enzymatic biodiesel serves these needs by expanding feedstocks, reducing waste, and increasing profitability.