Tuesday, August 14, 2012: 1:00 PM
Jefferson East, Concourse Level (Washington Hilton)
MBI is scaling up an ammonia-based biomass pretreatment, developed by Bruce Dale at Michigan State University, called Ammonia Fiber Expansion (AFEX™). This process has been shown to be effective on grasses and agricultural residues. Depending on the cellulosic biomass, ammonia loadings range from 0.7-2 g/g of biomass, temperatures from 70-200°C and residence times from 10-30 min at a pressure of 150-300 psi. Subsequently the pressure is released, vaporizing most of the ammonia; remaining ammonia must be evaporated and recycled. AFEX™ disrupts the biomass structure, changes the crystalinity of cellulose, alters the structure of lignin, redistributes lignin on the surface of the biomass and breaks the linkages that hold cellulose and hemicellulose together. These effects make AFEX™ treated material amenable to enzyme hydrolysis.
Hydrolysis has been carried out with solids loadings up to 20% w/v and the resulting sugar streams fermented (using a variety of production hosts bacteria, yeast and fungi) into a range of products including ethanol and dicarboxylic acids.
Advantages of sugar streams derived from AFEX™ treated biomass will be discussed and a vision of how AFEX™ would be deployed as part of a distributed supply chain to aid process logistics around a centralized bio-refinery will be presented.