Another company is entering the Cellulosic ethanol market place with the announcement that AE Biofuels, Cupertino, CA, has begun construction of an integrated cellulose and starch ethanol commercial demonstration facility in Butte, Montana. The plant will use proven patent-pending Ambient Temperature Cellulose Starch Hydrolysis (ATCSH) enzyme technology to optimize process conditions for multiple feedstocks. Non-food ethanol feedstocks used by the facility are expected to include switch grass, grass seed straw, small grain straw, and corn stalks alone and in combination with a variety of traditional starch and sugar sources. The 9,000 square foot pilot plant facility is expected to be fully operational in the second calendar quarter of 2008.
In 2007, AE Biofuels™ acquired enzyme technology from Renewable Technology Corporation and formed its ethanol technology subsidiary, Energy Enzymes. The company’s low-cost, multi-activity enzyme technology is designed to reduce operating and capital costs for both cellulosic ethanol and starch ethanol plants and provides a platform to integrate the two processes. AE Biofuels utilizes patent-pending ambient temperature enzymes to eliminate the up-front “cooking” process that occurs in traditional starch ethanol production. The company has three patents pending for the use and implementation of its technology.
The key to the integrated process is AE Biofuels’ patent pending ATSH process. The ATSH converts starch to sugar without the cooking step of conventional corn plants. ATSH enzymes convert the raw starch to sugar at ambient temperatures. Eliminating the cooking step allows the beer from the cellulosic fermentation process to be used as the starch process water, increasing the overall alcohol concentration of the final beer and reducing water use, energy use and feedstock costs.
This technology is a endorsement of enzyme technology as a viable means of producing cellulosic ethanol, if it meets the companies claims. The elimination of process steps, low cost enzymes and reduced cooling water consumption are all keys to lower cost cellulosic ethanol.