HYDROLYSIS OF LIGNOCELLULOSICS AT LOW ENZYME LEVELS - APPLICATION OF THE AFEX PROCESS

The presumed high cost of cellulase enzymes is seen as a major economi c hurdle in ethanol fuel production from lignocellulosic biomass. One way to reduce enzyme cost is to use much less enzyme per unit of bioma ss hydrolysed. The ammonia fiber explosion (AFEX) process produces a h ighly reactive biomass but the relationship between AFEX treatment con ditions, enzyme loadings and hydrolysis yields has never been thorough ly explored. We report here the effects of AFEX treatment on the initi al rates and 24 h hydrolysis yields for several crop residues and lign ocellulosic materials using low enzyme levels (1-5 IU/g dry biomass). Near theoretical sugar yields are obtained for some AFEX treatment con ditions at 1 IU/g for corn fiber and 5 IU/g for switchgrass. implicati ons of the experimental results are discussed. (C) 1996 Elsevier Scien ce.