A study on mass transfer-reaction kinetics of NO absorption by using UV/H_2O_2/NaOH process

摘要

Based on two-film theory, the mass transfer-reaction kinetics of NO absorption from flue gas by using UV/H_2O_2/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 H_2O_2 concentration increases from 0 to 1.0 mol/L, NO absorption rate increases from 0 to 1.55 × 10~(-5)mol/m~2s. NO absorption rate increases from 0.92 × 10~(-5) to 1.76× 10~(-5) mol/m~2s 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/m~2 s. However, NO absorption rate decreases from 1.61 × 10~(-5) to 1.54 × 10~(-5) mol/m~2 s as SO_2 concentration increases from 0 to 2000 ppm. The absorption process of NO from flue gas by using UV/H_2O_2/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_(N0) =P_(NO.G)·(1/K_(NO.G)+1/H_(NO.L)(K_(opl)·D_(NO.L)~(12)))~1· The tested results of kinetic model indicate that the calculated values are in good agreement with the experimental values.