采用真空膜蒸馏技术浓缩半纤维素水解液,考察了料液的流速、温度、浓度等对膜通量和挥发性发酵抑制物的影响,并进行浓缩试验。结果表明,膜蒸馏对木糖的截留率在99.99%。随着进料流速、进料温度、抑制物浓度和真空度的增加,膜通量增大;糠醛的分离因子随料液温度、真空度、抑制物浓度增加而减少,随流速的增加呈先增大后减小的趋势,而这些操作参数对甲酸、乙酸的分离因子影响不大。在进料温度65℃,料液流速1.5 L/min,真空度0.095 MPa的条件下进行连续浓缩试验,初始膜通量为11.9 kg/(m2.h),随着浓缩的进行,8 h后,膜通量仍维持在9.5 kg/(m2.h),糠醛浓度从0.46 g/L降低到0.23 g/L。
The effect of flow rate,temperature,concentration and the degree of vacuum on the flux and inhibitor in the concentration of hemicellulosic hydrolysatewas by using vacuum membrane distillation was investigated.VMD process was found 99.99% of the xylose was rejected.The result shows that the flux increased with flow rate,temperature,degree of vacuum and the concentration of inhibitors increased.The separation factor of furfural decreased as temperature,degree of vacuum and inhibitor concentration increased.These operation variables have little impact on the formic acid and acetic acid.When the the feed temperature at 65 ℃,with the liquid flow rate of 1.5 L/min and the vacuum degree of 0.095 MPa,the initial flux of membrane was 11.9 kg/(m2·h).After 8 hours,the flux of membrane was maintained at 9.5 kg/(m2·h),the concentration of furfural reduced from 0.46 g/L to 0.23 g/L.