Steam Explosion of Beech Wood: Effect of the Particle Size on the Xylans Recovery

Abstract

In this work, the effect of particle size and severity factors was investigated to find the optimum condition of steam explosion pretreatment on xylan recovery of beech wood. The beech wood particles with sizes of 0.16, 1, or 2 mm were steamed at 150–210 °C for 2.5–15 min before an explosive decompression. The results showed that the maximum xylan recovery was about 10% w/w wood with low concentrations of the inhibitors, which were obtained when the particle size is 1 mm and R0 = 3.65 (190 °C, 10 min). The smallest particle size may result in overcooking of biomass, leads to easily and high degradation of hemicelluloses sugars, whereas the largest particle sizes may result in incomplete autohydrolysis in biomass and lower extractability of hemicelluloses sugars. The obtained optimum condition for xylan recovery will improve the subsequent utilization (such as in food industry and other chemical products), prior to subsequent transformation of steam explosion pretreated wood (bioethanol and pellet).