| Due to the increasing lack of fossil fuels, people began to seek new alternative energy sources; hydrogen is considered as the most competitive energy future due to many advantages. At present, the use of fossil fuel re-obtained by the synthesis gas, in addition to containing a large number of H2, the other with CO-based gas also accounts for a certain percentage of impurities, in order to obtain high purity hydrogen, CO and other impurities in the gas separation is essential.This paper outlines the separation of the mixture of H2 and CO in many ways, taking the optimized pressure swing adsorption separation as a research focus, based on CO adsorption mechanism, produced a highly efficient CO composite adsorbent, additionally, this thesis investigated the process conditions of adsorbents as well as the adsorptive ability for one-component CO and investigated the influence of rare earth elements to adsorbent performance.Using copper chloride as the active component to study the different producing methods, carriers, in-situ activation of reduction temperature, reducing atmosphere, pre-carrier acidity and loadings, determined how these factors affect on the dynamic adsorption amount of CO. Characterized by a variety of analysis means showed that the best producing process is based on activated carbon adsorbent as a carrier, using mixed gas (10%H2,90%N2) to reduction, the best reduction temperature of 350℃, adsorbent were prepared by incipient impregnation. The article also carried out on commercial activated carbon acid modified and found that its adsorption properties achieve optimal when hydrochloric acid pretreatment concentration are 5mol/L. In addition, the paper also analyzes the optimal adsorbent loadings and found that the best activated carbon and copper chloride mass ratio are 40%(2:5), more than this value will be to plug the pore of adsorbent, the analysis results of BET, pore volume and pore size supplement confirmed this point.In comparing the producing proces, this thesis also tried to add the rare earth elements to improve the adsorptive ability of adsorbent and determined the different effects on adsorbent from different kinds of rare earth elements. Experimental results show that, if the adsorbent to add single element of 3% mass ratio such as lanthanum, cerium, zirconium on the basis of 40% copper, its absorption capacity are much higher than the CuCl2/AC which without adding elements, in which cerium element adsorption on the adsorbent have optimal effect. As for adding rare earth element like lanthanum and zirconium adsorbent, when the ratio of lanthanus and zirconium are 60%(3:5), the amount of absorption of CO reached peak value. However, as for the adsorbent adding with cerium and zirconium, the amount of absorption of CO reached peak value when the ratio of cerium and zirconium are 40%(2:5), better than lanthanum and zirconium composite adsorbent.In addition, the article also measured the effect on adsorption capacity of CO due to different CO ratio of feed gas at pressure swing absorption. In the adsorption process, with the CO content increasing, adsorbate penetration occurred earlier, the saturated adsorptive capacity of CO is also getting smaller, indicating the residence time of adsorbate in the fixed bed has a great impact. Finally, we also conduct some research about how to reuse adsorbent. The used adsorbent have lower absorptive capacity than fresh adsorbent, however, after repeated use of 15 times, the adsorbent have similar adsorptive capacity compared with the adsorbent that used only for one time. Indicating the recycled adsorbent has a more stable adsorptive performance. |
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