乙酸在超临界水中氧化分解的动力学研究  

Oxidative Degradation Kinetics of Acetic Acid in the Supercritical Water

作　　者：潘志彦[1] 林春绵[1] 周红艺[1] 杨馗[1] 

机构地区：[1]浙江工业大学生物与环境工程学院,浙江杭州310032

出　　处：《高校化学工程学报》2003年第1期101-105,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(29677025)

摘　　要：乙酸被认为是含碳氢有机物在超临界水中氧化降解的中间产物,甚至是关键的反应速率控制产物。今对影响超临界水中乙酸氧化降解的因素进行了实验研究,用总有机碳(TOC)含量来表示浓度,用幂指数方程来描述反应速率, 通过多参数曲线拟合, 求得了动力学参数; 反应活化能为144.8kJmol-1, 潜力因子为5.091010,对乙酸TOC浓度的反应级数为1.28, 对氧为0.4。结果表明:超临界水氧化法可以有效地去除水中的乙酸,去除率最高可达99%以上。在实验的条件范围, 氧气过量倍数和温度越高, 乙酸水溶液质量流量越小, 乙酸的降解率也越高。求得的动力学方程能较好地预测实际结果。Acetic acid was selected as the model compound for the experiments since it has been known as a key or a rate-controlling byproduct in the supercritical water oxidation of organic compounds. Acetic acid oxidation in supercritical water was examined at 380~420℃ and 24~30MPa,at reaction residence times up to 143 s, initial total organic carbon (TOC) from 873.5~2783.5moLL-1. The observed effects of the concentrations of TOC and oxygen on the global disappearance rates for TOC were correlated by using power-law rate expressions. Under the range of conditions studied, the reaction order of acetic acid oxidation is globally 1.28 order to concentration TOC of acetic acid and 0.4 order to oxygen and the reaction has an activation energy of 144.8kJmol-1 and a frequency factor of 5.09×1010. The results show that acetic acid can be oxidative-decomposed effectively in supercritical water, and with the increase of reaction temperature, concentration of acetate acid or oxygen excessive rate and decrease of mass-flow rate the decomposition rate of acetic acid increases and it may reach as high as 99%.

关 键 词：乙酸 超临界水 氧化分解 动力学 废水处理技术 降解 

分 类 号：X703[环境科学与工程—环境工程] O623.611[理学—有机化学]