Ni/Zr-MOF催化剂的制备及其在生物质热解中的应用

通过均匀沉淀法制备了以锆-金属有机骨架化合物(Zr-metal organic framework,Zr-MOF)为载体的Ni/Zr-MOF催化剂,并用于湿污泥和秸秆混合催化热解实验。采用元素分析、X射线荧光光谱(XRF)、热重分析(TG)、X射线衍射(XRD)、扫描电镜(SEM)和N_2吸附-脱附等温(BET)对载体和催化剂进行表征分析,通过一系列实验来探讨热解温度、秸秆添加量和Ni负载量对于湿污泥和秸秆混合催化热解制备富氢合成气的影响。结果表明,Zr-MOF载体颗粒均匀呈八面体,比表面积高达805.93 m~2/g,平均孔径为20.14 nm,为介孔结构。Ni/Zr-M OF催化剂具有较高的热稳定性和催化活性。与不添加催化剂相比,使用Ni/Zr-MOF催化剂在500℃下热解,H_2的产量从0.39 mol/kg显著提高到12.65 mol/kg。随着热解温度的升高,催化剂出现团聚现象,同时在反复使用之后其表面产生了少量的积炭,导致催化剂催化活性逐渐降低。因此,Ni/Zr-MOF催化剂适用于生物质低温催化热解。

Preparation of Ni/Zr-MOF catalyst and its application in pyrolysis of biomass

The catalytic co-pyrolysis of wet sewage sludge and wheat straw for hydrogen-rich gas production was experimentally investigated in a fixed bed reactor with Ni/Zr-MOF catalyst. The Ni/Zr-MOF catalyst was characterized by ultimate analysis, XRF, TG, XRD, SEM and BET. The effects of reactor temperature, straw content and Ni loading on the composition and yield of gasification gases were explored. The experimental results indicate that the mesoporous Zr-MOF support particles are octahedral with a specific surface area of 805.93 m²/g and an average pore diameter of 20.14 nm. The Ni/Zr-MOF catalyst has high thermal stability and catalytic activity. Compared with the pyrolysis without catalyst, the H₂ yield increases significantly from 0.39 mol/kg to 12.65 mol/kg using Ni/Zr-MOF catalyst at 500 ℃. After reuse, the carbon deposits are formed on the surface of catalyst. With the increase in reactor temperature, the catalytic activity decreases gradually due to the agglomeration of the catalyst. Therefore, the Ni/Zr-MOF catalyst is suitable for catalytic pyrolysis of biomass at lower temperature.