| The development of non-ferrous metal smelting industry in Yunnan Province has the energy and resources advantage. On the other hand, it is restrained with the environmental pollution from smelting waste gas and low level of comprehensive utilization. Mineral smelting furnace hot exhaust gas is containing plenty of CO, which can be used as raw material gas for one carbon (C1) chemical industry. The compounds of phosphorus, sulfur, arsenic, hydrogen cyanide and other reducing impurities present in the smelting waste gas could limit its application as chemical raw material gas to produce high accessional products, pollute the environment and result in the deactivation of catalysts.This thesis aimed to research adsorption removal of AsH3 in the mineral smelting furnace hot exhaust gas. Develop efficient adsorbent and explore the mechanism of adsorption. The effect of preparation conditions of adsorbent (the types of carrier, active components of adsorbents, impregnation concentration and calcination temperature) and experiment conditions (reaction temperature, oxygen content and space velocity) on the AsH3 adsorption removal process were investigated. N2-BET (N2 adsorption/desorption), XRD (X-ray powder diffraction), XPS (X-ray photoelectron spectroscopy), SEM-EDS (scanning electron microscopy-electron diffraction spectroscopy), Fourier transform infrared spectroscopy (FT-IR) and TPD (temperature-programmed desorption) were used to characterize the structure and surface properties of adsorbents and before or after adsorption reactions, and analyze reaction mechanism. Effect of H2S, PH3, COS, and CS2 on adsorption performance of COS are investigated, and the exhausted adsorbents can be regenerated with water vapor scrubbing method and N2 calcinations purging method, respectively. Experimental optimization Hβ zeolite as adsorbent support. A series of HP zeolite loaded by different metal salts solutions were prepared by impregnation method and tested for adsorption of arsine (ASH3). Based on results from adsorbent optimization experiments, Hβ zeolite modified with Cu(NO3)2 (denoted as Cu/HP) was found to possess significantly enhanced adsorption removal ability. The effects of impregnation concentration, calcinations temperature, reaction temperature, oxygen content and space velocity on the AsH3 adsorption removal process were investigated. The results indicate that adsorbents with 0.2 mol/L Cu(NO3)2 after calcining at 400℃ have superior activity for removing AsH3 And a breakthrough capacity of 43.7 mg AsH3/g adsorbent at 60℃ and 1.0% oxygen with space velocity of 1846h’’is shown in Cu/H(3 for the adsorption AsH3 processes. The pore structure, crystal structure and surface properties of H(3 zeolite samples were characterized by N2-BET, XRD, XPS, SEM-EDS, FT-IR and TPD. The XRD and BET results revealed that the crystalline phase of CuO formation on the zeolite surface and affected the properties of specific surface area and pore structure. The XPS results showed that the products of the adsorption AsH3 were As2O5 species, which accumulated on the zeolite surface and had a negative effect on the adsorption activity.According the actual situation of mining and metallurgy production process emissions, and explore the practical applications of the adsorbent. Effect of reducing impurity gas (such as H2S, PH3, COS, and CS2) on removal of AsH3 by Hβ zeolite. Because of the reducing impurity gas compete some adsorption sites, the AsH3 breakthrough adsorption capacity decreases significantly.The exhausted adsorbents can be regenerated with water vapor scrubbing method and N2 calcinations purging method, respectively. During the course of regeneration, the effects of the regeneration time was studied through investigating the performance of adsorption of regenerated adsorbent. The result was showed that water vapor scrubbing method and N2 calcinations purging method were all effective methods. The N2 calcinations purging regeneration method could effectively remove adsorbate on the surface of the adsorbent and restore most of the performance, the adsorbents can be recycled at least two times with little capacity loss. Compared with N2 calcinations purging regeneration method, water vapor scrubbing method is simpler and more economic. |
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