The discovery of effective methods toward nitric oxide (NO) removal by solution is valuable for the cost-effective flue gas control. In this study, it is first reported that nitrous oxide (N2O) is obviously suppressed by using copper oxide (CuO) combined with (NH4)2SO3 (NS) solution. CuO has been characterized, and the effects of reactants concentration, additives, temperature, pH and powder size on NO absorption process have been evaluated. The selectivity of N2O can drop from 91.30% to 11.25% under the optimum experimental conditions. Furthermore, based on the method of single-factor analysis, the inhibition of N2O is identified as the coeffect of NS/CuO. In addition, the pathways of NO removal are divided into two parts—N2O formation and NO absorption—and its ratio is calculated in the range of 0.29–0.53. Because of the continuous supply of NS from ammonia desulfurization, this study opens the feasibility of simultaneous desulfurization and denitrification.
The effects of various factors on the NO removal activity in the (NH 4 ) 2 SO 3 solution were investigated to explore more details and characteristics of the related reactions using full infrared sensor flue gas analyzer (FISFGA). It was found that the conversion yield of NO (9.0%–29.0%) was obviously improved with the increase of gas–liquid contact area, NO residence time and (NH 4 ) 2 SO 3 concentration as well as the adding of CuSO 4 . However, it was mainly limited by gas–liquid mass transfer rate and slightly inhibited by the gas velocity. Moreover, the FISFGA analysis revealed that two nitric oxide (NO) conversion route with different reduction product of N 2 O and N 2 existed simultaneously upon the existence form of SO 3 2− . It was confirmed by the calculations and the experiments of pH factor that the NO reduction steps were based on the following equation: (1) NO + HSO 3 − ⇋ N 2 O + SO 4 2− + H + ; (2) NO + SO 3 2− ⇋ N 2 + SO 4 2− . In this system, Eq. (1) with N 2 O product was the major pathway, but the ratio of Eqs. (2) to (1) was intensified in the presence of CuSO 4 . It is believed that the suitable additives could promote the NO reduction to N 2 furtherly.
危险品化学品经营许可证（带存储）