桉木循环强化自催化预水解过程中物质相间转移及其作用机制研究

Eucalyptus auto-catalyzed pre-hydrolysis process with circulation enhancement is one of novel processes with low energy comsumption, low pollution and low discharge. Research on substances pahse transfer and its functional mechanism during the process will promote the development of biomass-related industries, and provide a way of high technology and high level for utilization of eucalyptus. Components analysis and structural comparison are two main research methods in this research. Based on raw material properties, comprehensive components analysis of liquid phase, solid phase and gas phase during the pre-hydrolysis process will be carried out. Combined with material balance calculation, it will reveal catalyze mechanism with circulaiton enhancement, accumulation effect, energy saving effect, and so on under different pre-hydrolysis conditions, and reaction course and kinetics of eucaluptus auto-catalyzed pre-hydrolysis process will be investigated innovatively, which is characterized by taking gas phase changes into consideration. In addition, through pre-hydrolysis experiments of catalyzing model substances, interface properties analysis between solid phase and liquid phase, and structural analysis of solid phase, eucalyptus auto-catalyzed pre-hydrolysis mechanism will be revealed and completed further.

桉木循环强化自催化预水解工艺是一种低能量、低污染、低排放的新型预水解工艺，对这种工艺预水解过程中物质相间转移及其作用机理研究，可促进生物质利用相关行业的发展，同时为桉木开发利用提供一条高科技、高水平的道路。成分分析和结构分析是本课题的两条主线。以原料特性为基础，以预水解液循环量、预水解温度、预水解时间以及循环次数为变量，综合考量桉木循环强化自催化预水解过程中液、固、气三相成分变化，结合物料衡算，揭示了不同条件下的循环强化催化机制、累积效应、节能降耗性能等，同时创新性地获得了把气相变化纳入考量范畴的桉木循环强化自催化预水解工艺的反应历程和反应动力学。另外，通过催化模型物预水解研究、固液界面特性分析以及固相结构特性分析，进一步揭示并完善了桉木循环强化自催化预水解机理。

热水预水解是生物质精炼最为重要的技术之一，广泛用于溶解浆等的生产当中。现有热水预水解均采用间歇处理工艺，存在水解液中成分浓度低，难于充分利用，后续处理量大的问题。本研究将常规热水预水解的水解液循环用于桉木的预处理过程中，考察了处理过程中的温度效应、时间效应、循环量效应以及循环次数的影响，研究了液相成分的增浓累积效应，并采用模型物考察了催化效应。研究表明，循环强化预水解工艺对循环强化预水解液中有机酸具有富集作用，而酸的富集将进一步催化预水解过程；控制循环强化预水解工艺条件，可以量身定做实现不同糖组分的增浓效应，可以实现特定组分的原位转化，利于组分的分离和利用；温度效应导致木素的软化和半纤维素的破坏，使得结构出现变化，为桉木成分的降解和溶出打开了通道。桉木循环强化自催化预水解工艺是一种低能量、低污染、低排放的新型预水解工艺，在为桉木开发利用提供一条高科技、高水平的道路的同时，将推动用于生物质精炼的连续式和间歇式循环热水预水解工艺的开发。