Xiao-bo Zhang

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.

The Effect of Heat Decomposition Temperature on the Dissolution Rate of Magnesium-based Materials for Wet Flue Gas Desulfurization

Magnesium hydrate is the absorbent in magnesia scrubbing wet flue gas desulfurization. Its dissolution rate has a great impact on the performance of SO2 removal. Further, magnesia is the heat decomposition product of magnesite. The effect of magnesite heat decomposition temperature on the dissolution rate of magnesium hydrate is investigated in this study. As can be seen from the experimental results, magnesium hydrate dissolution rate increased with increasing heat decomposition temperature up to 700°C and then decreased with the increase of heat decomposition temperature. This is caused by the change of magnesite heat decomposition mechanism at a different heat decomposition temperature.

A Thermodynamic Study of Simultaneous Removal of SO2 and NO by a KMnO4/Ammonia Solution

Molar reaction Gibbs function change, molar reaction enthalpy change, equilibrium constant, and the equilibrium partial pressure of SO2 and NO for the reaction of simultaneous removal of SO2 and NO by using aqueous KMnO4/ammonia solution are calculated based on the principle of chemical thermodynamics. The results show that simultaneous removal of SO2 and NO by using KMnO4/ ammonia solution is available.

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.

Dissolution Rate of Limestone for Wet Flue Gas Desulfurization in the Presence of Citric Acid

Dissolution rate of limestone for wet flue gas desulfurization in the presence of citric acid was measured by pH-stat method. It was found that limestone dissolution rate in the presence of citric acid was controlled by mass transfer. As can be seen from the experimental results, in the presence of citric acid, limestone dissolution rate increased with increasing stirring speed and reaction temperature. When pH value was greater than or equal to 5.5, due to the formation of calcium citrate, citric acid would inhibit the dissolution process of limestone. And the inhibition effect was more obvious at higher pH value.Copyright