焙烧温度对Ni-Mg基蜂窝状催化剂生物燃气重整调变性能的影响

采用浸渍法制备了Ni、Mg双金属负载在堇青石表面形成的蜂窝状催化剂,研究了焙烧温度对催化剂结构和生物质粗燃气重整反应性能的影响.结果表明,在不同焙烧温度下主要有NiO和NiMgO₂固溶体物相生成.相比于其他焙烧温度,催化剂在650 ℃焙烧温度下更有利于镍活性金属位的分散和活性位数量的增加.在干重整反应条件下,CH₄、CO₂的转化率以及H₂、CO产率随焙烧温度的升高呈现先增加后降低的变化趋势,在650 ℃焙烧温度下达到最高.在水蒸气重整反应条件下主要发生烃类产物与H₂O和CO₂的重整反应以及水煤气变换反应,焙烧温度的升高有利于水煤气反应的进行.此外,焙烧温度对于干重整反应条件下的H₂/CO体积比调节影响较小,而对于水蒸气重整反应条件下的H₂/CO体积比可进行选择性调节.

Effect of calcination temperature on Ni-Mg based monolithic catalyst for biomass gas reforming reaction

The Ni-Mg based monolithic catalyst was prepared by impregnation method. Effects of calcination temperature on microstructure and biomass gases reforming performances of the catalyst were investigated. The results indicated that there was the formation of NiO and NiMgO₂ in the catalyst during calcination at different temperatures. Compared to other calcination temperatures, calcinating at 650 ℃ facilitated the dispersion of NiO on the cordierite and the increase of active sites. Under the dry reforming condition, conversion of CH₄ and CO₂ increased first, and then decreased gradually with the increase of calcination temperature. The CH₄ and CO₂ conversion reached the highest value as the calcination temperature is 650 ℃. A similar trend was observed for the yield of H₂ and CO. Under the steam reforming condition, increasing calcination temperature promoted water gas shift reaction. In addition, changing calcination temperature may adjust selectively the ratio of H₂/CO under the steam reforming condition.