Abatement technologies for high concentrations of NO_xand SO₂removal from exhaust gases: A review

The Chemical Behaviors of Nitrogen Dioxide Absorption in Sulfite Solution

“…Besides the above-mentioned nitrogen-sulfur compounds, Chen et al [32] and Zhuang et al [32,33] thought that the sulfite radicals could be formed by the reaction between NO2 and sulfite, the sulfite radicals could undergo either recombination or reaction with oxygen. By comparing Figure 4 with Figure 5, it can be seen that the amount of other S compositions is much lower than that of other Similarly, the calculated TS t is also more than the sum of detected SO 3 2− and SO 4 2− , as shown in Figure 5. Other S compositions besides SO 3 2− and SO 4 2− account for about 4% to 9% in the reaction system.…”

“…The sole N source in the inlet flue gas is NO 2 . When NO 2 laden gas contacts with sulfite solution, the transfer of the NO 2 into absorption solution occurs, meanwhile, reactions take place in the liquid phase, and the main products of NO 2 absorption in flue gas are NO 3 − and NO 2 − , especially NO 3 − in absorption solution dramatically increases due to the absorption of NO 2 and the oxidation of NO 2 − . HNO 3 is considered to involve gas and liquid states existing in reaction system, and the gaseous HNO 3 in outlet flue gas is from both HNO 3 escape in absorption solution and the reaction between NO 2 and H 2 O in the gas phase.…”

“…Although the combination of the commonly practiced de-NO x and de-SO 2 processes can meet the limitations of SO 2 and NO x emissions stipulated by environmental legislation, traditional NO x and SO 2 removal technologies in a stepwise manner have some drawbacks, such as the requirement for large construction site, high capital investment, and high operation costs. Thus, the emerging technologies for the simultaneous removal of NO x and SO 2 are to be extensively developed [2,3].…”

Kinetic modelling of NO heterogeneous radiation-catalytic oxidation on the TiO2 surface in humid air under the electron beam irradiation

“…(2) (3) where: r NO , r NO2 are the reaction rates at the active surface of catalyst for radiation-catalyst oxidation of NO and NO 2 [6], NO and NO 2 are consumed or generated along the reaction vessel as follows: The values of constants k NO , k NO2 , K NO , K NO2 and K H2O , for photo catalytic oxidation of NO, were defi ned in papers [5,6] and listed in Table 1.…”

“…Therefore, theoretical study of the process of electron-beam treatment of fl ue gas are fi rst being looked for by many researchers. A hybrid system of a catalyst, combined with EB, might be one of the solutions [2]. In this case, the oxidation processes of NO x and SO 2 take place on the catalyst surface in fl ue gas under the electron-beam treatment.…”