陶瓷膜接触器化学吸收氮氧化物的传质过程与阻力分析

To overcome the problems of large device, high operating cost and catalyst poisoning and deactivation in the selective catalytic reduction technology (SCR), Al₂O₃ ceramic membrane with an average pore diameter of 100 nm was hydrophobic modified and assembled into a membrane contactor, NaClO₂ was used as absorbent to carry out the application research of ceramic membrane contactor in the field of denitration of flue gas. The stability of ceramic membrane contactor in chemical absorption denitrification and the effect of the process parameters (i.e. gas flow rate, concentration of absorbent, liquid of absorbent, pH of absorbent) on NO removal efficiency and mass transfer flux were investigated in detail. Based on the resistance series model, the total mass transfer coefficient equation was established. The experiments showed that the NO removal efficiency and mass transfer flux of NO were stable at about 99% and 0.038 mol•m^-2•h^-1 during 600 min operation of the ceramic membrane contactor. The increase of the intake air flow will promote the absorption of NO, and the absorption liquid has the highest oxidation absorption performance at pH=3, while increasing the concentration of the absorption liquid will enhance the removal effect of NO. The mass transfer performance of NO is controlled by the resistance of the gas phase, liquid phase and the membrane phase at the same time. The mass transfer resistance analysis results show that the increase of gas flow rate can decrease the gas phase resistance, increasing the concentration of the absorbent and the lower pH can reduce liquid phase resistance. The study has a good application prospect in denitration of flue gas.