【摘要】 考察了木质纤维素乙醇发酵液中各组分对乙醇透过聚二甲基硅氧烷(PDMS)-silicalite-1渗透汽化膜传质性能的影响。结果表明:酵母细胞、玉米秸秆残渣和发酵用无机盐可增加乙醇通过膜的通量和选择性;而葡萄糖和甘油的存在会对乙醇的透膜传质产生负面影响;木质纤维素水解后的产物如糠醛和羟基丙酮,表现出对膜分离乙醇轻微的抑制作用。本文建立了渗透汽化优先透醇与纤维素乙醇发酵集成过程,批次发酵20 h后乙醇产率从最初的12.95下降到10.22 g/(L·h),60 h后乙醇产率下降为0,葡萄糖消耗速率与乙醇消耗产率呈同样趋势;连续发酵过程中,乙醇产率较稳定地维持在13.30 g/(L·h)。实验证明,集成过程可及时地将产物乙醇分离出去,能够有效地消除产物抑制,提高乙醇生产速率和葡萄糖转化率。更多还原

【Abstract】 We studied the effects of components in lignocellulosic ethanol fermentation broth on ethanol transfer through polydimethylsiloxane-silicalite-1 pervaporation membrane to tackle product inhibition by integrated with ethanol fermentation. Yeasts,corn stover residues and salts could increase the ethanol flux and selectivity through the membrane,whereas glucose and glycerol had negative effects on membrane performance. Lignocellulosic hydrolysates,such as furfural and hydroxyacetone,slightly influenced separation performance. In batch fermentation,ethanol productivity reduced from 12. 95 to 10. 22 g /( L·h) after 20 h,and became 0 after 60 h. The glucose consumption curve also confirms the same tendency. However,the ethanol fermentation integrated with pervaporation gave a stable ethanolproductivity about 13. 30 g /( L·h). Experiments further proved that integrated process of lignocellulosic ethanol fermentation and ethanol-selected pervaporation through polydimethylsiloxane-silicalite-1membrane could eliminate product inhibition,improve ethanol productivity and glucose conversion rate very effectively.更多还原