Intensified Process for Biodiesel Production

Although interest in biodiesel is rapidly increasing, the process by which biodiesel is synthesized has not changed much in the last two decades and is far from efficient. Currently, most biodiesel is made by a homogeneous-catalyst-based transesterification process, wherein soybean oil is reacted with methanol in the presence of sodium methoxide. After transesterification, the homogeneous alkaline catalyst is mixed-in with the biodiesel and the glycerol byproduct. Purification of both the biodiesel and the glycerol, by removing the homogeneous alkaline catalyst, is an energy and labor-intensive operation that produces a waste stream. In addition, the glycerol byproduct resulting from this process is of low quality. This project will develop a catalytic reactor that uses a heterogeneous catalyst for the highly efficient, high throughput, and low cost production of biodiesel. The reactor consists of thousands of microreactors coated with a highly-active, proprietary heterogeneous catalyst. Phase I demonstrated technical feasibility by determining the optimal reactor configuration (including reactor geometry and catalyst loading) and the optimal reactor operating conditions (including reaction temperature, molar ratio of soybean oil to methanol, and space velocity). Phase II will involve scaling the process from laboratory scale to pilot scale, producing a large-size honeycomb catalyst for pilot plant testing, and demonstrating commercial viability. Commercial Applications and Other Benefits as described by the awardee: The application of the microreactor technology in biodiesel production should significantly increase biodiesel productivity, simplify product separation and purification, improve glycerin quality, eliminate the washing step and associated waste stream, and reduce plant size, and reduce capital and processing costs. In turn, these advantages should expedite the substitution of petroleum diesel with domestically produced alternative fuel, decrease energy consumption and its associated environmental impact, reduce U.S. dependence on foreign oil imports, and enable the U.S. transportation industry to sustain a strong, competitive position in domestic and world markets.