Supercritical water oxidation of coal: Investigation of operating parameters' effects, reaction kinetics and mechanism
Supercritical water oxidation of coal: Investigation of operating parameters' effects, reaction kinetics and mechanism
复制标题
DOI：
10.1016/j.fuproc.2010.09.010
复制
发表时间：
2011-03
影响因子：
7.5
通讯作者：
Shuzhong Wang;Yang Guo;Liang Wang;Yu-zhen Wang;Donghai Xu;Honghe Ma
中科院分区：
文献类型：
--
作者：
Shuzhong Wang;Yang Guo;Liang Wang;Yu-zhen Wang;Donghai Xu;Honghe Ma
在连续管式反应器中进行了煤的超临界水氧化反应。实验结果表明，化学需氧量（COD）的去除率对温度的变化没有明显的依赖性。停留时间超过一定值后，影响不显著。超临界水氧化反应的自由基机理可能是煤在实验氧过量范围内转化率较低的原因。与其他参数相比，压力的影响不太显著。从实验数据中回归了一个全局幂律速率表达式。煤浆和氧化剂的反应级数分别为1.79和0.28。反应活化能Ea为112.3kJmol−1，指前因子k 0为412（mol/L）−1.07s−1。模型与实验数据的偏差在± 9%以内。煤的超临界水氧化过程可能有自由基机理、氧化水解机理和酚羟基氧化机理。
Supercritical water oxidation (SCWO) of coal was conducted in a continuous tubular reactor under various reaction conditions. Our experimental results show that the removal rate of chemical oxygen demand (COD) had no significant dependence on the temperature variations. Effect of residence time was less significant as exceeded fixed values. Free radical mechanism of SCWO reaction may be a possible explanation for the relative low conversion rate of coal at the range of tested oxygen excess. Compared with other parameters, effect of pressure was less significant. A global power-law rate expression was regressed from experimental data. The reaction orders for coal slurry and oxidant were 1.79 and 0.28 respectively. The reaction activation energy Eawas determined to be 112.3kJmol−1, and the pre-exponential factor k0was 412 (mol/L)−1.07s−1. The deviation between the model and experimental data was within ±9%. Free radical mechanism, oxidation and hydrolysis mechanisms and phenolic hydroxyl oxidation mechanism were considered to be the possible mechanisms for the SCWO process of coal.