生物质秸秆在水中热化学液化研究

在100ml半连续固定床萃取反应器中，利用等温实验技术，对大连地区的玉米、大豆和高粱3种生物质秸秆在水中的液化反应进行研究，实验采用4因素3水平的正交设计考察了压力、溶剂流量，升温速率及原料等因素对生物质千秆在水中的液化反应行为。实验结果表明，在整个液化过程中始终存在着裂与缩聚反应的竞争，在前期以裂解为主，后期以缩合为主，而发生这一转折的时间在很大程度上受到反应条件的综合影响，在实验条件下，以总收率为考察目标时最佳工艺是采用玉米秸秆为液化原料，升温速率4k/min，压力在20MPa，溶剂流量为1ml/min，此时秸秆的干基总收率为87．0％，液体收率为58．6％，研究发现水在临界点附近表现了较好的反应特性，是具有开发和应用潜力的生物质液化介质。

Thermochemical Liquefaction of Biomass in High Pressure Water

Liquefaction of three kinds of biomass (corn straw, durra straw and legume straw) was investigated in a semi continuous fixed bed with a non isothermal fluid extraction technique. The experiments were carried out in aqueous solution, under different conditions of pressure, heating rate and flow rate of solvent without any addition of catalyst or hydrogen. The results indicates that the cracking and condensation reactions coexist during the liquefaction process and cracking plays a important role at low temperature while condensation dominates at high temperature which mainly depends on reaction conditions. The type of biomass affects the liquefaction for their different content of cellulose, hemi-cellulose and lignin. The highest conversion (87.0%daf) is obtained with corn straw at a heating rate of 4?K/min, 20?MPa and flow rate of 1?ml/min . Those experiments show that water is a great potential solvent and reactant in dealing with biomass to obtain liquid products at high pressure and an appropriate temperature.