Removal of C2H4 from a CO2 Stream by Using AgNO3-Modified Y-Zeolites

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• 作者：Jinxia Zhou ; Yongchun Zhang ; Xinwen Guo ; Anfeng Zhang ; Xiaomeng Fei
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2006
• 出版时间：August 30, 2006
• 年：2006
• 卷：45
• 期：18
• 页码：6236 - 6242
• 全文大小：262K
• 年卷期：v.45,no.18(August 30, 2006)
• ISSN：1520-5045

文摘

Removal of C₂H₄ from a CO₂ stream is very important in ultrapurification of CO₂ for its application andutilization. However, it is difficult to remove C₂H₄ completely from a CO₂ stream via conventional cryogenicdistillation because the volatility of C₂H₄ is similar to that of CO₂. Another choice is the catalytic combustionmethod, but it is an energy-inefficient process, especially when it is coupled with the cryogenic distillation.Selective adsorption for removing C₂H₄ might be a promising alternative. A great effort has been made inC₂H₄/C₂H₆ separation and recovery of C₂H₄. There were, however, few reports about the removal of a traceamount of C₂H₄ from a CO₂ stream. In this study, the AgNO₃-modified NaY and HY zeolites are preparedand their adsorption performances are evaluated via a series of experiments of fixed-bed adsorption, frontalchromatographic adsorption, and temperature-programmed desorption (TPD). The structure of the sliver saltafter being impregnated onto the supports has been characterized by thermogravimetric/differential thermalanalysis, X-ray diffraction, and transmission electron microscopy. The experimental results show that bothNaY and HY have poor adsorption selectivities of C₂H₄ from the C₂H₄/CO₂ stream because of a strongercompetition of CO₂ with C₂H₄ for the physical adsorption sites, and AgNO₃/NaY and AgNO₃/HY, favoredby their strong chemical adsorption sites, Ag ions, are able to remove C₂H₄ from the CO₂ stream effectively.