| The development of non-ferrous metal metallurgy in Southwest China has the resources and energy advantage. However, it is restrained with the air pollution from melting waste gas and low comprehensive utilization level. Mineral smelting furnace hot exhaust gas has high concentration CO, which can be used as raw material gas for mono-carbon (C1) chemical industry. The compounds of phosphorus (PH3), sulfur (H2S, COS, and SO2), arsenic (ASH3), hydrogen cyanide (HCN) and other reducing impurities present in the waste gas not only could limit its application as chemical raw material gas to produce high accessional products, simultaneously, but also could result in air pollution issues.This thesis aimed to research adsorption purification of mineral smelting furnace hot exhaust gas, develop superior adsorbent and explore the mechanism of adsorption. The carrier, active components of adsorbents and the effect of experiment conditions were studied. N2adsorption-desorption (N2-BET), scanning electron microscope (SEM), energy dispersive spectrometer (EDS). X-ray photoelectron spectroscopy (XPS) were used to characterize adsorbents and before or after adsorption reactions, and analyze reaction mechanism. Effect of CS2, C4H4S, H2S, PH3on adsorption performance of COS are studied, and the adsorbents were regenerated with gas method and solvent method respectively.The carriers were γ-Al2O3and active carbon in researches. Firstly, the adsorption performance of COS by γ-Al2O3was studied. The experiment results and characterizations of γ-Al2O3indicated that5.0%KOH could be active components of adsorbents which were used to purify COS at low-temperature with micro-oxygen. The purification efficiency of COS at the conditions of2.0%O2and80℃was above95%. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of KOH appears to improve the COS removal efficiency significantly, during which, H2S and SO42-were presumably formed. Secondly, Cu-Co-KW adsorbent was used for carbonyl sulfide (COS) removal. The effects of COS concentration, reaction temperature and relative humidity on the COS removal were investigated. A breakthrough of33.23mg/g adsorbent at60℃and30%relative humidity with1.0%oxygen is shown in Cu-Co-KW for removing COS. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of Cu(OH)2CO3-CoPcS-KOH appears to improve the COS removal capacity significantly, during which, SO42" were presumably formed, strongly adsorbed, and present in the micropores ranging from0.7to1.5nm. According to the current study results, the activated carbon impregnated with Cu(OH)2CO3-CoPeS-KOH promises a good candidate for COS adsorbent, with the purified gas meeting requirements for desirable chemical feed stocks.For the study of the actual situation of mining and metallurgy production process emissions, and explore the practical applications of this adsorbent. Influence of concurrent substances on removal of COS by activated carbon, such as CS2, C4H4S, H2S, PH3. Because of the concurrent substances compete some adsorption sites, the COS breakthrough adsorption capacity decreases.Activated carbon and γ-Al2O3used by removing low concentration COS were regenerated with gas method and solvent method respectively. During the course of regeneration, the effects of some factors which include the regeneration time and temperature were studied through investigating the performance of desulfuration of regenerated adsorbent. It was showed that gas regeneration method and solvent regeneration method were all effective methods. The nitrogen gas regeneration could effectively remove adsorbate on the surface of the adsorbent and restore most of the performance. Compared with the gas regeneration method, the water vapor regeneration is simple, economical. |
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