周昊, 成毅, 周明熙, 倪玉国. Pt涂层蜂窝金属和Ce改性Fe2O3催化CO的性能对比[J]. 工程科学学报, 2020, 42(1): 70-77. DOI: 10.13374/j.issn2095-9389.2019.04.08.005
引用本文: 周昊, 成毅, 周明熙, 倪玉国. Pt涂层蜂窝金属和Ce改性Fe2O3催化CO的性能对比[J]. 工程科学学报, 2020, 42(1): 70-77. DOI: 10.13374/j.issn2095-9389.2019.04.08.005
ZHOU Hao, CHENG Yi, ZHOU Ming-xi, NI Yu-guo. Analysis of CO catalytic oxidation by Pt-loading catalyst and Ce-doped Fe2O3[J]. Chinese Journal of Engineering, 2020, 42(1): 70-77. DOI: 10.13374/j.issn2095-9389.2019.04.08.005
Citation: ZHOU Hao, CHENG Yi, ZHOU Ming-xi, NI Yu-guo. Analysis of CO catalytic oxidation by Pt-loading catalyst and Ce-doped Fe2O3[J]. Chinese Journal of Engineering, 2020, 42(1): 70-77. DOI: 10.13374/j.issn2095-9389.2019.04.08.005

Pt涂层蜂窝金属和Ce改性Fe2O3催化CO的性能对比

Analysis of CO catalytic oxidation by Pt-loading catalyst and Ce-doped Fe2O3

  • 摘要: 铁矿石烧结烟气中含有较高浓度的CO(体积分数0.5%~2%),因此对其进行CO脱除意义重大。为了探究不同类型催化剂的催化效果,采用浸渍法制备了Pt涂层蜂窝金属催化剂和铁铈氧化物催化剂,并通过X射线荧光光谱分析(XRF)对其组分含量进行了分析。二者在模拟烧结烟气中进行CO脱除性能的对比实验,活性测试表明,不同CO初始体积分数、烟气温度以及水汽含量对CO催化氧化的脱除效率影响较大。当模拟烟气中不含水汽的时候,二者在180 ℃及更高温度下对CO的脱除效率均能达到60%以上。反应温度为180 ℃,水汽体积分数为11.7%时,Pt负载型催化剂中的CO转化率为63.9%,而该条件下Ce改性Fe2O3催化剂的CO转化率仅为34.9%。当温度在180~300 ℃范围内,Pt负载型催化剂具有较好的抗水性,且继续升高温度,水汽体积分数增加对催化剂效率的负面影响更显著。如水汽体积分数从0增加到27.1%时,与180 ℃时的催化效率相比,Pt负载型催化剂在240 ℃时的催化效率由73.9%降至62.3%,降幅远远增大。另外,对这两种催化剂进行了抗硫性测试。当水汽体积分数为0时,Ce改性Fe2O3催化剂抗硫性更佳,但当SO2和水汽同时存在的情况下,Pt负载型催化剂具有更好的抗硫性。因此,在实际烧结中建议采取高效的脱硫措施并布置脱水层以减少其对于催化剂的负面影响。

     

    Abstract: The iron ore sintering flue gas contains a relatively high CO concentration (volume fraction of 0.5%‒2%); therefore, it is of great significance to remove CO. To study the catalytic effect of different catalysts, typical Pt-supported catalyst and Ce-doped Fe2O3 catalyst were prepared by impregnation, and their components were analyzed by X-ray fluorescence. The activity results show that different initial CO concentrations, flue gas temperature, and water vapor volume fraction have a great influence on the removal efficiency of CO catalytic oxidation. When there is no water vapor in the flue gas, the CO removal efficiency of the two catalysts is over 60%. When the reaction temperature is 180 ℃ and the water vapor volume fraction is 11.7%, the CO conversion efficiency of the Pt-supported catalyst is 63.9%, but the CO conversion efficiency of the Ce-doped Fe2O3 catalyst is only about 34.9%. Furthermore, the results show that the Pt-supported catalyst has a better water resistance in the range of 180‒300 ℃. If the reaction temperature is higher, the increase in water vapor volume will have a more negative impact on the catalytic efficiency of both catalysts. For example, when the volume fraction of water vapor increases from 0 to 27.1%, the catalytic efficiency of the Pt-supported catalyst drops from 73.9% to 62.3%, which decreases much more compared to the case of 180 ℃. In addition, the sulfur resistance of the two catalysts was also tested. The Ce-doped Fe2O3 catalyst is more resistant to SO2, when there is no water vapor. However, when SO2 and water vapor exist at the same time, the Pt-supported catalyst has better sulfur resistance. Therefore, during the actual sintering process, it is recommended to adopt efficient desulfurization measures and arrange the water absorption layer in order to reduce the negative impacts on catalysts.

     

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