循环流动固定床光催化反应器动力学数学模拟

以甲基橙为模型反应物,研究了连续循环固定床光催化反应器的动力学过程.根据光催化氧化过程特点,分析并建立了准一级反应动力学方程,对该反应系统的动力学过程进行动态数学模拟,用四阶Runge-Kutta法进行数值计算,结果表明数学模拟与实验数据相吻合.在该光催化反应体系中,处理量增加时实际反应速率常数k基本不变,而表观反应速率常数kapp变小,二者之间关系与反应器体积对处理量体积比（γ）密切相关;反应速率常数受起始浓度影响很大,在15～150 μmol?L－1浓度范围内,lnk=－0.48lnc0]＋1.42;反应速率常数与光强的关系为k∝I0.5;反应速率常数受溶液pH值的影响也很大.

Kinetics Modeling Study on Continuous Circulative Flow ImmobilizedPhotocatalytic Reactor

The kinetic process in a tubular continuous-flow photo-reactor equiped with titanium dioxide immobilized on glass fiber-net has been studied by using methyl orange as a model reactant.The process has been described carefully,and modeled by using dynamic partial differential equation.Since the solution of the equation was complicated,the numerical solution has been undertaken by using a fourth-order Runge-Kutta scheme.The results show that the mathematical simulated values are consistent with the experimental data.Under the condition of different treated reactant amount the actual reaction rate constant k is approximately identical,but the apparent reaction rate constant kapp decreases with increasing treatment of reactant amount.The initial concentration has a great influence upon the rate constant.Below 15 μmol?L－1 of the initial concentration the rate constant tends to be a constant.In the range of 15～150 μmol?L－1,the influence of the initial concentration on the reaction rate constant can be expressed as:lnk=－0.48lnc0＋1.42.The dependence of reaction rate constant on UV irradiation intensity is k∝I 0.5.The pH of initial solution is an important factor in the photocatalysis reaction.