文摘
Use of a commodity feedstock with uniform physical and chemical characteristics can maximize the efficiency of sugar production in a lignocellulosic biorefinery. However, efficient handling and storage necessitates dry biomass, while effective bioconversion is maximized with high moisture biomass. To bridge this gap, the effect of moisture content on hybrid poplar bioconversion was investigated. Fresh hybrid poplar chips were both oven- and air-dried and rehydrated by soaking in water prior to SO2-catalyzed steam explosion. Following enzymatic hydrolysis, pretreated solids derived from air-dried and oven-dried chips (10% and 0% moisture content) were 11–24% less digestible than never-dried chips at 50% moisture content. Upon soaking the same poplar chips in water prior to SO2 impregnation, pretreatment, and hydrolysis, there was a dramatic improvement in digestibility of up to 44%, thought to be due to improved SO2 uptake and subsequent hemicellulose hydrolysis in the dried chips. Monomeric glucose and xylose yields after pretreatment and hydrolysis of over 500 kg/tonne raw biomass were achieved from oven-dried and soaked biomass compared to only 349 kg/tonne raw biomass for unsoaked oven-dried biomass. In contrast, no improvement was observed upon soaking for air-dried or never-dried hybrid poplar chips.
