化工学报 ›› 2011, Vol. 62 ›› Issue (6): 1554-1562.

• 催化、动力学与反应器 • 上一篇    下一篇

喷雾干燥成型温度对浆态床合成甲醇CuO/ZnO/Al2O3催化剂活性及稳定性的影响

李忠,张小兵,郭启海,刘岩   

  1. 1太原理工大学煤科学与技术教育部重点实验室,2太原煤气化公司技术中心
  • 出版日期:2011-06-05 发布日期:2011-06-05

  • Online:2011-06-05 Published:2011-06-05

摘要:

通过浆态床反应器的评价,考察了喷雾干燥成型温度对CuO/ZnO/Al2O3催化剂催化合成甲醇的活性及稳定性的影响。结果表明,低于225℃进行喷雾干燥时,前驱体中的水分蒸发不完全,高于225℃则前驱体物相组成的结晶程度进一步提高,均不利于催化剂的活性和稳定性。225℃喷雾干燥所制备的催化剂活性和稳定性均较佳,时空收率与失活率分别达到了166.7 g·(kg cat)-1·h-1和0.16% ·d-1,与常规干燥制备催化剂[时空收率为172.2 g·(kg cat)-1·h-1,失活率为0.43%·d-1]的活性基本相当,但稳定性得到大幅提高。催化剂结构表征分析表明,经喷雾干燥成型制备的催化剂与常规干燥制备的催化剂相比,两者在CuO微晶的平均粒径、比表面积以及孔径分布上基本保持了一致,不同的是前者为粒径约70μm细小均匀的球形颗粒状,而后者则呈现为粒径约120μm的无规则颗粒状。

关键词: 浆态床反应器, CuO/ZnO/Al2O3催化剂, 稳定性, 喷雾干燥成型

Abstract:

The influence of the spray drying temperature on the performance of the CuO/ZnO/Al2O3 catalyst used for methanol synthesis is studied in a slurry reactor.The results show that the spray drying temperature lower or higher than 225℃ will lead the precursor to water residual or crystallinity degree higher than optimum respectively, which will disadvantage the performance of the catalyst.The performance of the catalyst that spray dried at 225℃ is optimal, and its space time yield and deactivation rate reach to 166.7 g·(kg cat)-1·h-1and 0.16% ·d-1 respectively.The space time yield is equivalent to the catalyst that conventional dried[172.2 g·(kg cat)-1·h-1,0.43%·d-1], but its stability is improved much.The characterization of the catalysts and precursors indicates that the structure data of the catalyst spray and conventional dried, such as mean diameter of CuO crystallite, specific surface area and hole diameter distribution between 5.8—20 nm, are mainly equivalent with each other. The only difference is that the catalyst particle that spray dried presents homogeneous sphere with mean diameter about 70 μm

Key words: 浆态床反应器, CuO/ZnO/Al2O3催化剂, 稳定性, 喷雾干燥成型