Microcosmic Configuration Design And Experimental Study Of Nickel-based Materials For Carbonyl Sulfide Deep Removal

Carbonyl sulfide (COS) is widely exist in industrial feed gas and exhaust gas. It is not only a poison to industrial catalysts, but also one of the main sources of the stratosphere sulfate aerosols. Therefore, deep removal of COS is in high demand. In this paper, a combination of experimental and theoretical method was used to design and prepare the mixed oxides materials for COS deep removal. Firstly, the nature of the surface active sites on the pure oxide for COS removal was studied. Secondly, the adjustment effect of different methods on the electronic structure of pure oxide and the nature of the surface active sites was studied by density functional theory. Finally, the material is prepared and systematically characterized. Through the above research, a kind of ideal material for COS deep removal was obtained. In addition, the mechanism of desulfurization performance improvement was proposed. The main results of this thesis and regular rules are as follows:1. NiO is a potential material for desulphurization for COS removal. The higher ability of provide electronic, the better desulfurization performance. Hydroxyl groups can react with the adsorbed CO molecular fragment on Ni atoms, which can effectively reduce the "carbon deposit effect" on the surface of the material.2. The result of theoretical calculation showed that the substitution of Al atoms can effectively improve the surface Lewis NiO alkaline intensity. The result of the experimental results showed that hydrotalcite derivative oxide has this kind of crystal structure. The best calcination temperature is 400℃. The best composition is Ni/Al=3.3. A moderate amount of KOH and K2CO3 loading can improve the COS removal efficiency of the hydrotalcite derivative oxide. However, KC1 and KNO3 loading can laed to a decline of the desulfurization efficiency. The result of mechanism study showed that improvement of Lewis basic strength and material surface hydroxyl number is the effective way to improve the desulfurization activity of the materials for COS deep removal.