Quantifying reductions in soaking in aqueous ammonia pretreatment severity and enzymatic hydrolysis conditions for corn stover pellets

Abstract The benefits of using pelleted corn stover compared to loose corn stover with low severity soaking in aqueous ammonia pretreatment and reduced enzyme loadings were studied. Loose and pelleted corn stover were treated with the same set of pretreatment and hydrolysis conditions. A range of low to high severity pretreatment conditions and enzyme loadings were tested to determine conditions to achieve 90% glucose yields. Glucose yields from pelleted biomass reached 90% with reduced pretreatment severities, enzyme loadings, hydrolysis time, or various combinations of these. At the highest enzyme loadings, use of pelleted corn stover enabled reductions in hydrolysis time up to 58%. It also allowed 80% reduction in enzyme loading at higher pretreatment conditions. At moderate pretreatment levels, either enzyme loadings can be reduced by 40% or hydrolysis time by up to 48%. Using pelleted biomass as a biorefinery feedstock allows flexibility in production with different processing options.