Sunday, May 3, 2009
3-43
Development of a continuous AFEX process
John Glassbrook, Chandra D. Nielson, Josh J. Videto, Timothy J. Campbell, David Senyk, and Farzaneh Teymouri. MBI International, 3900 Collins Road, Lansing, MI 48910
It has been shown that pretreating biomass with concentrated ammonia in the AFEX (Ammonia Fiber Expansion) process increases yields of fermentable sugars. Up to now, the AFEX process has been conducted as a batch process. However, conducting AFEX as a batch process limits the ability to commercially apply the process. Recently MBI has developed an innovative continuous AFEX (CAFEX) reactor capable of providing five critical functions required for the completion of the AFEX treatment. These functions are: 1) pressurizing the moistened biomass and ammonia, 2) mixing and generating a homogeneous mixture of liquid ammonia and moistened biomass, 3) heating the moistened biomass and ammonia, 4) providing adequate residence time, 5) releasing the pressure quickly. A prototype designed to process 300lb/hr of dry biomass has been built and constructed. The CAFEX prototype accomplishes several of the aforementioned functions simultaneously and also is capable of meeting AFEX process conditions. Since there are no moving parts the MBI CAFEX reactor has no dynamic seals that pose a risk of ammonia leakage into the work environment. Currently we are using distillers dried grains and solubles (DDGs) as a model feedstock to test the validity and functionality of our CAFEX reactor. The efficiency of the process is evaluated via enzyme hydrolysis. Hydrolysis of the DDGs treated in the continuous AFEX process are benchmarked with hydrolysis of theDDGs treated in the batch AFEX reactor under comparable conditions. The detail of the process and the results will be presented in this paper.
Web Page: www.mbi.org