Simultaneous removal of SO2 and NO by wet scrubbing using aqueous chlorine dioxide solution

Simultaneous absorption of SO2 and NO from flue gas with KMnO4/NaOH solutions.

Removal of SO2 and NO from flue gas by wet scrubbing using an aqueous NaClO2 solution

The absorption−oxidation of nitric oxide (NO) by aqueous solution of sodium persulfate (Na2S2O8) has been studied in a bubble column reactor operated in semibatch mode. The effects of different process variables such as the persulfate concentration (0.01−0.2 M), temperature (23−90 °C), pH (4−12), sodium chloride concentration (0−0.5 M), and NO concentration (500−1000 ppm) were studied. In general, the NO fractional conversion (percent of inlet NO removed) at all temperatures increased almost linearly with persulfate concentration up to about 0.1 M, after which it started to level off. Increased temperature led to an increased fractional conversion of NO at all persulfate levels. At 0.1 M persulfate concentration, conversions of up to 69% and 92% were observed at 70 and 90 °C, respectively. Solution pH and chloride concentration were both found to affect NO absorption at higher temperatures. The effect of pH was moderate, but sodium chloride showed a significant effect on NO absorption at 70 °C, to the poi...

Absorption and Oxidation of Nitric Oxide (NO) by Aqueous Solutions of Sodium Persulfate in a Bubble Column Reactor

Removal of NO from flue gas by aqueous chlorine-dioxide scrubbing solution in a lab-scale bubbling reactor.

Individual and Simultaneous Absorption of Dilute NO and SO2 in Aqueous Slurries of MgSO3 with FeII-EDTA

The rates of single and simultaneous absorptions of dilute SO2 and NO in aqueous mixed solutions of NaClO2 and NaOH were measured at 25°C using a stirred vessel with a plain gas-liquid interface. In the SO2-NaClO2 system, the absorption rate exceeded the gas-film controlled rate, which implies the possibility of gas-phase oxidation of SO2 due to the evolved C1O2. In the SO2-(NaClO2+NaOH) system, the absorption rate agreed with that under gas-film controlled conditions. In the (SO2+NO)-(NaClO2+NaOH) system, the reduction of the NO absorption rate in the presence of SO2 substantially exceeded that evaluated through the decrease in interfacial concentration of NaClO2 and NaOH due to surface reaction with coexisting SO2. The rate of absorption of SO2 exceeded the gas-film controlled rate. The decomposition of NaClO2 proceeds to a greater degree during simultaneous absorption than the single absorption of SO2.

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And nitric oxide in aqueous mixed solutions of sodium chlorite and sodium hydroxide

The absorption of such lean NO(x) as encountered in flue gases in aqueous mixed solutions of NaClO2 and NaOH was carried out using a stirred vessel with a plane interface at 25 C and atmospheric pressure. The rate of NO2 absorption was analyzed by the chemical absorption theory under the fast-reaction regime. The reaction which prevailed was found to be the parallel reactions involving oxidation and hydrolysis, and to be second order with respect to NO2. The second-order rate constant for the hydrolysis was evaluated as 3.09 x 10 to the 8th L/mol s. The order of reaction relative to ClO2(-) was derived as unity for chlorite concentrations greater than 1.0 M. The third-order rate constant for the oxidation was derived as 7.32 x 10 to the 8th (L/mol)-squared/s at /NaOH/ 0.20 M. For the absorption of NO, there appears to be a gradual jump in absorption rate at the interfacial concentration of NO ranging from 5 x 10 to the -7th to 2 x 10 to the -6th mol/L. Above this transition region, the order of reaction in NO approaches 2, whereas below the transition region, the order of reaction becomes unity.

Ichibei Kudo

Papers

Individual and Simultaneous Absorption of Dilute NO and SO2 in Aqueous Slurries of MgSO3 with FeII-EDTA

And nitric oxide in aqueous mixed solutions of sodium chlorite and sodium hydroxide

Absorption of Lean NOx in Aqueous Solutions of NaClO2 and NaOH

Absorption of nitric oxide in aqueous solutions of iron(III)-EDTA chelate and aqueous slurries of magnesium sulfite with iron(III)-EDTA chelate

Absorption of Nitric Oxide in Aqueous Ferrous Sulfate Solutions