Qiang Jin

The Absorption Kinetics of NO into Weakly Acidic NaClO Solution

NO is a major air pollutant from coal-fired power plants. A combined removal of SO2 and NO is a prospective process. In this paper, the absorption kinetics of NO into weakly acidic NaClO solution was studied in a stirred tank reactor. It was proven that the absorption process occurred under the fast pseudo-mth reaction regime, and the reaction was found to be first-order with respect to both NO and NaClO. When the initial pH value of NaClO solution is 5.5, it has the best performance for NO absorption. The frequency factor and the average activation energy of this reaction were 7.96 × 108 m3/(mol s) and 28.15 kJ/mol, respectively. The absorption rate of NO increased with increasing reaction temperature.

Absorption of NO from simulated flue gas by using NaClO2/(NH4)2CO3 solutions in a stirred tank reactor

Experiments were performed in a stirred tank reactor to study the absorption kinetics of NO into aqueous solutions of NaClO2/(NH4)2CO3 solutions. The absorption process is a fast pseudo-reaction, and the reaction was found to be second-order with respect to NO and first-order with respect to NaClO2, respectively. The frequency factor and the average activation energy of this reaction were 4.56×1011 m6/(mol2 s) and 33.01 kJ/mol respectively. The absorption rate of NO increased with increasing reaction temperature, but decreased with increasing (NH4)2CO3 solution.

Low-temperature selective catalytic reduction of NO on CeO2–CuO/Al2O3 catalysts prepared by different methods

CeO2–CuO/Al2O3 catalysts were prepared by three different methods and their activities for selective catalytic reduction (SCR) of NO with NH3 were investigated. As can be seen from the experimental results, the catalyst prepared by the single-step sol–gel (SG) method showed the best SCR activity and resistance to SO2 and H2O. In order to investigate the relationship between the preparation method and the performance of SCR catalysts, the catalysts were characterized by using Brunauer–Emmett–Teller, X-ray diffraction, temperature programmed reduction with hydrogen, temperature programmed desorption with ammonia, X-ray photoelectron spectroscopy, Fourier transform infrared and thermo-gravimetric analysis techniques. It was found that the excellent performance of CeO2–CuO/Al2O3 catalyst prepared by the single-step SG method should be resulted from its large surface area, low crystallinity, high oxygen storage capacity, high NH3 adsorption capacity, high concentration of surface chemisorbed oxygen, weak sulphation process and weak water absorption.

Absorption of NO by Aqueous Solutions of KMnO4/H2SO4

The absorption of NO in aqueous solutions of KMnO4 and H2SO4 was carried out in a stirred tank reactor under atmosphere pressure. The results indicated that the absorption process was under a fast pseudo-m th reaction regime. The reaction between NO and aqueous solutions of KMnO4/H2SO4 was found to be first-order with respect both to NO and to KMnO4. The addition of H2SO4 to KMnO4 solutions increased the absorption rate of NO and increasing reaction temperature was also favorable to the absorption of NO.