滴流床苯酚催化湿式氧化反应动力学及反应器模型

Research on Reaction Kinetics and Reactor Model of Catalytic Wet Oxidation of Aqueous Phenol in a Trickle Bed Reactor

在自制的滴流床反应器中,以苯酚配水溶液为研究对象,采用负载型MnOx/-γAl2O3作为催化剂,研究了苯酚催化湿式氧化过程.通过实验数据的拟合分析,提出了苯酚催化湿式氧化本征反应速率表达式,计算了液体流率为1.6 L/h时不同温度下催化剂外表面湿润效率以及不同温度下与一定的氧分压相平衡的水中溶解氧浓度;由实验数据拟合得到苯酚催化湿式氧化表观反应动力学模型参数,并建立了关于积分式滴流床苯酚催化湿式氧化的反应器模型,比较了不同氧分压、进液苯酚质量浓度、进液流率下苯酚去除率的计算值与实验值.结果显示：当氧分压大于1.0 MPa时,计算值与实验值能较好吻合,当氧分压较低时,氧气从气相到液相存在一定的传质阻力.在苯酚进液质量浓度为0~5 000 mg/L时,苯酚对催化氧化反应的抑制作用不明显.在进液流率为0~2.05 L/h时,存在一定的外扩散阻力.

The catalytic wet oxidation （CWO） of aqueous phenol solution was investigated in the Trickle-Bed Reactor （TBR） in the presence of a catalyst composed of manganese oxide supported over γ-alumina. The rate formula of intrinsical reaction about the CWO of phenol was developed through simulation of the experimental results. Outer surface wetting efficiency of catalyst at different reaction temperatures at liquid flow L = 1.6 L/h and oxygen solubility （mg/L） at different temperatures and oxygen pressures was calculated theoretically. Furthermore, the apparent reaction kinetic model parameters of the CWO of phenol were obtained in the light of simulation of the experiment data, and the reactor model about of the CWO of phenol in the trickle-bed also developed. The comparison of the experimental data of phenol removal ratio with the calculation value of kinetic model at different oxygen pressures, phenol feed concentrations and feed liquid flows showed that the model calculation results could fit well with the experimental results when oxygen pressure was up to 1.0 MPa, and the mass-transfer resistance of oxygen from gas to liquid could be observed when oxygen pressure was lower than 1.0 MPa. In the range of experimental phenol feed concentration （0 - 5 000 mg/L）, phenol did not obviously restrain catalytic oxidation reaction. In the range of experimental feed liquid flow （0 - 2.05 L/h）, three exited some outer diffusion resistance.