A study on mass transfer–reaction kinetics of NO absorption by using UV/H2O2/NaOH process

Based on two-film theory, the mass transfer–reaction kinetics of NO absorption from flue gas by using UV/H2O2/NaOH process was investigated in a photochemical reactor. The effects of several operating parameters on NO absorption rate were studied. The mass transfer-reaction process of NO absorption was analyzed. A simple NO absorption rate equation is also established and tested. The results indicate that when H2O2 concentration increases from 0 to 1.0 mol/L, NO absorption rate increases from 0 to 1.55 × 10−5 mol/m2 s. NO absorption rate increases from 0.92 × 10−5 to 1.76 × 10−5 mol/m2 s when NaOH concentration increases from 0 to 0.01 mol/L. As NO concentration increases from 200 to 1000 ppm, NO absorption rate increases from 0.82 × 10−5 to 3.23 × 10−5 mol/m2 s. However, NO absorption rate decreases from 1.61 × 10−5 to 1.54 × 10−5 mol/m2 s as SO2 concentration increases from 0 to 2000 ppm. The absorption process of NO from flue gas by using UV/H2O2/NaOH process is a pseudo-first-order fast reaction with respect to NO. The relationship between NO absorption rate, mass transfer and chemical reaction can be described by the following equation: N NO = p NO, G · 1 k NO, G + 1 H NO, L k ov 1 · D NO, L 1 / 2 - 1 . The tested results of kinetic model indicate that the calculated values are in good agreement with the experimental values.