Cu-Cr-O and Cu-Ce-O Regenerable Oxide Sorbents for Hot Gas Desulfurization
详细信息 查看全文
- 作者：Zhijiang Li and Maria Flytzani-Stephanopoulos
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：1997
- 出版时间：January 1997
- 年：1997
- 卷：36
- 期：1
- 页码：187 - 196
- 全文大小：480K
- 年卷期：v.36,no.1(January 1997)
- ISSN：1520-5045
文摘
Binary Cu-Cr-O and Cu-Ce-O oxides were studied in thiswork as regenerable sorbents forhigh-temperature fuel gas desulfurization.CuO-Cr2O3 and CuO-CeO2sorbents can removeH2S from simulated coal-derived fuel gas to less than5-10 ppmv in the temperature range of650-850 
C. The presence of stableCuCr2O4 in CuO-Cr2O3solids retains some copper in theCu2+ or Cu1+ oxidation state, which canaccount for the high H2S removal efficiency. InCuO-CeO2 sorbents, however, CuO is easily reduced to coppermetal. Participation of reduced ceriumoxide in sulfidation can explain the observed high desulfurizationefficiency. TGA tests andXRD analysis indicate that sulfidation proceeds through partial initialreduction of the CuO-Cr2O3 sorbents: CuO 
Cu/Cu2O CuxS (x < 2). Reductionkinetics were studied in the TGAover temperature ranges of 550-850 and 350-850 C, respectively,for the CuO-Cr2O3 andCuO-CeO2 materials. The sulfidation kineticparameters were measured in the temperaturerange of 450-850 C after prereduction of both sorbents. Thesulfidation of metal copper inCr2O3 and CeO2-xmatrices is a fast reaction with low activation energy, 19.8 and 16.6kJ/mol,respectively. Both types of sorbents can be fully regenerated withdiluted air. The regenerationtemperature affects the reaction pathway and the regenerability of thesolid composition.
C. The presence of stableCuCr2O4 in CuO-Cr2O3solids retains some copper in theCu2+ or Cu1+ oxidation state, which canaccount for the high H2S removal efficiency. InCuO-CeO2 sorbents, however, CuO is easily reduced to coppermetal. Participation of reduced ceriumoxide in sulfidation can explain the observed high desulfurizationefficiency. TGA tests andXRD analysis indicate that sulfidation proceeds through partial initialreduction of the CuO-Cr2O3 sorbents: CuO Cu/Cu2O CuxS (x < 2). Reductionkinetics were studied in the TGAover temperature ranges of 550-850 and 350-850 C, respectively,for the CuO-Cr2O3 andCuO-CeO2 materials. The sulfidation kineticparameters were measured in the temperaturerange of 450-850 C after prereduction of both sorbents. Thesulfidation of metal copper inCr2O3 and CeO2-xmatrices is a fast reaction with low activation energy, 19.8 and 16.6kJ/mol,respectively. Both types of sorbents can be fully regenerated withdiluted air. The regenerationtemperature affects the reaction pathway and the regenerability of thesolid composition.