超/亚临界水两步法水解稻秆制备还原糖  

Reducing Sugars Production from Rice Straw by a Two-step Hydrolysis with Supercritical/Subcritical Water

作　　者：刘慧屏[1] 徐刚[1] 罗鹏[1] 银建中[1] 

机构地区：[1]大连理工大学化工机械学院,辽宁大连116024

出　　处：《生物质化学工程》2011年第4期17-22,共6页Biomass Chemical Engineering

摘　　要：以稻秆为原料,采用两种间歇式反应工艺,对其在超/亚临界水条件下两步水解过程进行研究。重点考察反应温度、反应时间、液固比对水解行为的影响,并与超临界一步法水解工艺进行了比较。结果表明,对稻秆进行低温段水解,液固比100∶1,190℃、40 min条件下最大还原糖得率21%,将液固比降低到40∶1,20 min即可获得与液固比100∶1时40 min反应相当的还原糖得率。将低温段水解残渣作为高温段第二步水解的原料,在380℃、20 s条件下获得最大还原糖得率为57%,超/亚临界两步法水解稻秆工艺所获得的总还原糖得率为45%。相同条件下,用超临界一步法直接对稻秆进行水解,40 s时获得还原糖得率最大,为32%。超/亚临界水条件下两步水解比一步法水解工艺的还原糖得率提高了13个百分点。Reducing sugars can be derived from biomass via hydrolysis process. A two-step hydrolysis with supercritical/subcritical water were applied for rice straw hydrolysis. The effects of key factors as the ratio of liquid phase to solid phase, reaction temperature and time on the yield of reducing sugars were evaluated. The relationship of rice straw liquefaction rate vs. ratio of liquid phase to solid phase were investigated. Rice-straw were hydrolyzed using a two-step hydrolysis process with subcritical water combined with supercritical water and one-step supereritical water hydrolysis process respectively. The maximum yield of reducing sugars was about 21% at 190 ~C for 40 min when the ratio of liquid phase to solid phase of the substrates was 100 ： 1, while treating the rice straw using the two-step process. Meanwhile, the same yield of reducing sugars were obtained when the ratio of liquid phase to solid phase of the substrates was reduced from 100：1 to 40：1 at 190 ~C for only 20 rain. The residues of the rice straw from the two-step process were hydrolyzed at 380 ~C for 20 s ; the maximum yield of reducing sugars was about 57 %. Under the same conditions, the maximum yield of reducing sugars was about 32 % by one-step supercritical water hydrolysis. The total yield of reducing sugars by two-step method was 45 %. Thirteen percentage points was increased compared with the yield obtained by one-step method.

关 键 词：生物质 稻秆 超/亚临界水 水解 还原糖 

分 类 号：TQ353.6[化学工程]