助剂对泡沫金属微反应器内二甲醚水蒸气重整制氢的影响

Effect of promoter on performance of hydrogen production from steam reforming of dimethyl ether with a metal foam microreactor

  • 摘要: 采用共沉淀耦合机械混合法制备了CuO-ZnO-Al2O3/HZSM-5双功能催化剂用于二甲醚水蒸气重整制氢的研究,结合BET、H2-TPR、XRD、SEM等表征手段,在泡沫金属微反应器内考察助剂Cr、Zr、Ce、Co对双功能催化剂催化性能的影响。研究结果表明,加入Cr助剂后, 可以有效降低催化剂的平均孔径和还原温度,并抑制催化剂制备过程中氢氧化锌晶相的形成,催化剂的低温催化性能明显提高,二甲醚的转化率和氢收率在较低温度下即可分别达到99%和95%,表现出了良好的低温反应活性。考察了反应温度、空速和水醚比等条件对二甲醚水蒸气重整催化剂催化活性的影响,在250℃、空速3 884 mL/(g·h)、水醚比为5的条件下,CuO-ZnO-Al2O3-Cr2O3/ HZSM-5催化二甲醚水蒸气重整反应进行50 h,二甲醚的转化率维持在97%以上,催化剂的活性没有明显下降。

     

    Abstract: The CuO-ZnO-Al2O3/HZSM-5 catalyst prepared by co-precipitation and mechanical mixing with HZSM-5 was used for hydrogen production from steam reforming of dimethyl ether. The effects of Cr, Zr, Co and Ce promoters on catalyst performance were investigated by means of X-ray diffraction(XRD), temperature programmed reduction (H2-TPR), SEM and BET. The results showed that addition of promoter Cr can reduce the average pore diameter and reduction temperature of catalyst effectively, and inhibited the form of Zn(OH)2 in the catalyst preparation process. The conversion of dimethyl ether and hydrogen yield reaches 99% and 95% respectively at low reaction temperature. The effects of reaction termperature, space velocity and steam-to-DME ratio were investigated. At the conditions of 250℃, the space velocity of 3884mL/(g.h), H2O/DME=5, over 97% of DME conversion was obtained over the CuO-ZnO-Al2O3-Cr2O3/HZSM-5 catalyst and the catalytic activity has no obvious deactivation during 50h durability test.

     

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