Abstract:

The decomposition kinetics of glucose and 5-hydroxymethylfurfural catalyzed by copper chloride were measured in small volume high^-pressure vessel batch reactors, at various temperatures from 423.15 K to 463.15 K and catalyst concentration from 0 to 0.08 mol·L^-1.The results showed that their conversion went up with the increase of reaction temperature and catalyst concentration, resulting in higher yield of levulinic acid.By comparing the correlation coefficients, it was confirmed that both glucose and 5-hydroxymethylfurfural decomposition are first order reaction.By using first order kinetics equation, the activation energies of desired and undesired reaction were estimated, 134.65 kJ·mol^-1 and 144.1 kJ·mol^-1 for glucose decomposition，131.97 kJ·mol^-1 and 135.18 kJ·mol^-1 for 5-hydroxymethylfurfural decomposition, respectively.This work would provide important basic data not only for the exploration of reaction mechanism of glucose decomposition, but also for the development of high activity and high selectivity catalyst.

Key words:

高温液态水, 葡萄糖, 5-羟甲基糠醛, 乙酰丙酸, 氯化铜, 分解反应动力学

摘要： 以纤维素的水解产物葡萄糖为模型物质，利用小型高压反应釜系统地测定了不同反应温度 （423.15K～463.15K）和不同的氯化铜浓度（0～0.08M）对葡萄糖和中间产物5-羟甲基糠醛（5-HMF）分解动力学的影响，结果表明反应温度的提高和氯化铜浓度的增加都能促进葡萄糖和5-HMF的分解反应，提高乙酰丙酸（LA）的收率。采用相关系数比较法确定了葡萄糖和5-HMF分解反应的级数均为一级。利用一级动力学模型对葡萄糖和5-HMF分解反应动力学数据进行了拟合，求得葡萄糖分解生成5-HMF的主副反应活化能分别为134.65kJ.mol^-1、144.1kJ.mol^-1，而5-HMF分解生成LA的主副反应活化能分别为131.97kJ.mol^-1、135.18kJ.mol^-1。本文的研究工作能为葡萄糖水解反应机理的探索以及高活性、高选择性催化剂的开发提供重要的基础数据。

关键词:

高温液态水, 葡萄糖, 5-羟甲基糠醛, 乙酰丙酸, 氯化铜, 分解反应动力学