Antonoplis R A, Blanch H W, Freitas R P, Sciamanna A F, Wilke C R
Lawrence Berkeley Laboratory and Department of Chemical Engineering, University of California, Berkeley, California 94720.
Biotechnol Bioeng. 1983 Nov;25(11):2757-73. doi: 10.1002/bit.260251117.
Saturating wood particles with HCl gas under pressure was found to be an effective pretreatment prior to subjecting wood to dilute acid hydrolysis. Pretreament is necessary to release sugars from wood because of the tight lattice structure of cellulose. The HCl gas makes the cellulose more susceptible to subsequent acid hydrolysis and the glucose yield is doubled when dilute acid hydrolysis is preceded by HCl saturation at high pressure. The saturation was most effectively performed in a fluidized bed reactor, with pure HCl gas fluidizing an equal volume of ground wood plus inert particles. The fluidized bed effectively dissipated the large amount of heat released upon HCl absorption into the wood. Batch reaction times of 1 h at 315 psia gave glucose yields of 80 degrees and xylose yields of 95 degrees after dilute acid hydrolysis. A model was developed which proposed gas diffusing through the solid as limiting the reaction rate and this was found to effectively describe the HCl-wood reaction in the fluidized bed. The HCl was found to form a stable adduct with the lignin residue in the wood, in a ratio of 3.33 mole of lignin monomer. The adduct was broken upon the addition of water.
发现在对木材进行稀酸水解之前，在压力下用HCl气体饱和木材颗粒是一种有效的预处理方法。由于纤维素紧密的晶格结构，预处理对于从木材中释放糖是必要的。HCl气体使纤维素更易于随后的酸水解，并且当在高压下进行HCl饱和后再进行稀酸水解时，葡萄糖产率会加倍。在流化床反应器中进行饱和最为有效，纯HCl气体使等体积的磨碎木材加惰性颗粒流化。流化床有效地消散了HCl被木材吸收时释放的大量热量。在315 psia下进行1小时的间歇反应时间，稀酸水解后葡萄糖产率为80%，木糖产率为95%。开发了一个模型，该模型提出气体通过固体扩散限制了反应速率，并且发现这有效地描述了流化床中HCl与木材的反应。发现HCl与木材中的木质素残留物形成稳定的加合物，其比例为每3.33摩尔木质素单体。加水后加合物会分解。
