UV/H2O2氧化联合CaO吸收脱除NO的传质-反应动力学

摘要

在实验室规模的光化学反应器中,基于实验研究、动力学理论以及双膜理论,研究了UV/H2O2氧化联合CaO吸收(UV/H2O2-CaO工艺)脱除燃煤烟气中NO的传质-反应动力学.分析了NO吸收的传质-反应过程,明确了NO吸收过程的主要控制步骤和强化措施,测定了关键的动力学参数,推导了NO吸收过程的理论模型.结果表明:在实验范围内,NO吸收速率随着NO浓度的增加几乎呈线性增加.随着H2O2浓度和CaO浓度的增加,NO的吸收速率均呈现先增加后变缓的趋势.UV/H2O2-CaO工艺脱除NO是一个拟一级快速反应过程,强化气相主体扰动、增加气液接触面积和提高NO分压可有效提高NO的吸收速率.NO吸收速率方程的计算值和实验值具有较好的一致性.%Based on experimental results, kinetics and two-film theory, the mass transfer-reaction kinetics was experimentally studied for NO removal using a combination process of UV/H2O2 oxidation and CaO absorption (UV/H2O2-CaO process) in a lab-scale UV-bubbling column reactor. The mass transfer-reaction process of NO absorption was analyzed to determine its rate controlling step and some measures that can effectively strengthen NO absorption, and some key kinetic parameters were measured and a theoretical model for NO absorption was established. The results indicate that under experimental conditions, the rate of NO absorption almost linearly increases with NO concentration. With increase of H2O2 and CaO concentrations, the efficiencies of NO removal increase greatly at first, and then its change is small. The absorption of NO by combined UV/H2O2-CaO process follows pseudo-first-order kinetics. The NO absorption rate can be effectively strengthened by increases of turbulence in gas phase body, gas-liquid contact area and NO partial pressure. The values calculated from the theoretical model of NO absorption are in good agreement with the experimental values.