Study Of CuO-based Adsorbents For Low Temperature Desulfurization Application

The large amount of carbon dioxide?CO₂?emissions has a very negative impact on the environment,which is the high-quality gas source for the production of food grade quality CO₂,so recovery of CO₂ is of great significance for carbon resources utilization and environmental protection.However,the high concentration of CO₂ contained many impurities such as hydrogen sulfide?H₂S?,which can restrict the utilization of CO₂.Hydrogen sulfide?H₂S?is a kind of corrosive and stinky gas.Even a small amount of hydrogen sulfide can not only pollute the environment and cause serious harm to the human body,but also corrode the equipment and pipelines.The content of hydrogen sulfide in carbon dioxide used for production of food must be less than 0.1 ppm.It is of great importantance to remove H₂S from the CO₂ gas through effective technology.However,the capacity of low-temperature adsorbents is low and there is water pollution in the preparation process,so high desulfurization efficiency adsorbents made by mechanical mixing method is an important area of study.In this paper,CuO-based adsorbents for low-temperature was prepared by mechanical mixing method and the effects of supported materials desulfurization performance of CuO-based adsorbents were studied.Conclusions are drawn from this work as follows:In order to improve the desulfurization performance of CuO,MCM-41,SiO₂,big-hole-Al₂O₃ and Al₂O₃ are used as in preparing supported CuO-based adsorbents by mechanical mixing method.Compared with CuO,the specific surface area,the dispersion of the active components and the desulfurization performance of the CuO-based adsorbents with the addition of MCM-41 and SiO₂ were improved.The adsorbents with MCM-41 exhibited the highest breakthrough capacity,which is 63.25 mg g^-1.The carrier plays an important role in the high desulfurization performance of adsorbent.The relationship between the content of the carrier and the desulfurization performance was investigated in detail.It was found that the adsorption capacity will decrease after increased first with the addition of the carrier improved,among them,the adsorbents with 10 wt%MCM-41 and 3 wt%SiO₂ exhibited the highest breakthrough capacity,which is 73.37 mg g^-1 and 63.25 mg g^-1.The carrier should not be added too much,otherwise they will inhibit the desulfurization performance.The effect of reaction space velocity,temperature and balance gas type were explored.It was found that the adsorption capacity will increase after decreased first with the reaction space velocity improved.With the reaction temperature improved,the adsorption capacity will increase first,and decrease then.SO₂ impurities will appear when it's under the condition of 130?,so the appropriate desulfurization temperature should be no higher than 100°C.The balance gas CO₂will inhibit the H₂S adsorption.Finally,clay is used in preparing supported CuO-based adsorbents by mechanical mixing method.The adsorption capacity will decrease after increased first with the addition of the clay improved,among them,the adsorbents with 20 wt%clay exhibited the highest breakthrough capacity,which is 141.69 mg g^-1.