基于Cu和Pt基催化剂的乙醇水蒸气重整制氢试验研究

Steam Reforming of Ethanol to Produce Hydrogen Over Cu and Pt-based Catalysts

乙醇水蒸气重整制氢的车载应用不但可在线产生富氢气体,解决氢气的储运问题,还可实现混富氢气燃烧,降低排放.为得到较优的重整制氢方案,模拟内燃机尾气温度条件,在燃料重整试验台上实现乙醇的水蒸气催化重整制氢过程.在不同催化剂Cu49Zn21Al18Zr12和Pt/CZO/Al2O3条件下,考察了反应温度、水醇摩尔比和空速对重整气中φ(H2)的影响.研究表明:当反应温度为723～973 K、空速为720 h-1、水醇摩尔比分别为6∶1和4∶1时,二者φ(H2)的平均值分别为47.78%和40.26%.催化剂Pt/CZO/Al2O3重整制氢的产量高于Cu49Zn21Al18Zr12,尤其是在823 K以上的高温区域.但是与Pt/CZO/Al2O3相比,Cu49Zn21Al18Zr12成本低廉,在873 K以上的温度区域,重整气中φ(H2)也相当高.因此,基于Cu49Zn21Al18Zr12催化剂的乙醇水蒸气重整对于车载制氢更加具有可行性.

Stream reforming ethanol can not only produce hydrogen on board and solve the problem of storage, but also realize the mixed combustion of fuel with hydrogen-rich reformed gas and improve engine emissions. To get the optimal experiment method, the experiment was performed on a self-designed apparatus that could provide the similar temperature as the engine exhaust gas. The effects of reaction temperature, water/ethanol molar ratio and gas hourly space velocity （GHSV） on hydrogen concentration in the outlet gases were experimentally investigated over Cu49Zn21Al18Zr12 and Pt/CZO/Al2O3 catalyst. Results show that hydrogen productivity through steam reforming of ethanol over Pt/CZO/Al2O3 catalyst is higher than Cu49Zn21Al18Zr12 catalyst, especially when the reaction temperature is up to 823 K. The average values of hydrogen concentration are 40.26% and 47.78% when the reaction temperature ranges from 723 K to 973 K, GHSV is 720 h^-1, water/ethanol molar ratio are 6：1 and 4： 1, respectively. However, as the Cu49Zn21Al18Zr12 catalyst gains a relatively higher productivity over 873 K and lower cost than Pt/CZO/Al2O3 catalyst, steam reforming of ethanol over Cu49Zn21Al18Zr12 catalyst may become a promising and practical way for producing hydrogen on vehicles.