Effect of Mechanical Refining Energy on the Enzymatic Digestibility of Lignocellulosic Biomass

Abstract

Mechanical refining of lignocellulosic biomass has emerged as a promising technology for the improvement of enzymatic hydrolysis yields. Further research is necessary to understand the effects of mechanical refining at different conditions to allow for further optimization of the process. In this research, the impact of refining intensity (specific edge load; kWh/m) is investigated by the use of multiple refining passes to reach equivalent total specific refining energy (SRE) using a 12-in. disk refiner. In addition, the effect of adjusting gap-width vs adjusting consistency to increase refining energy is explored. Results show that enzymatic carbohydrate conversion is a function of SRE, independent of refining intensity. At lower enzyme loadings, gap-width adjustments were observed to be most effective at improving enzymatic digestibility. At higher enzyme loadings carbohydrate conversions leveled-off slightly as SRE increased, implying that there may be an economically optimum degree of refining.