原料中的NH_3含量对甲醇制丙烯催化剂性能的影响

Influence of NH_3 in Raw Material on Catalyst for Methanol to Propylene

在连续流动固定床微型反应器中,对甲醇制丙烯的ZSM-5分子筛催化剂的性能进行了评价,并采用XRD、吡啶吸附-FTIR和TG等方法对反应后的催化剂进行了表征,考察了原料中的NH3含量对催化剂性能的影响,同时考察了NH3含量与催化剂寿命和甲醇转化率的关系。实验结果表明,在催化剂装填量10 g、常压、480℃、甲醇重时空速1.0 h-1、水与甲醇的质量比0.69的反应条件下,NH3的存在对ZSM-5分子筛催化剂的晶型结构没有影响,但对酸性影响较大;随NH3含量的增加,尤其是当NH3含量大于0.010%(w)时,催化剂的积碳量显著降低,催化剂的寿命大幅缩短。

The influence of NH3 content in reaction materials on the ZSM-5 zeolite catalyst for methanol to propylene was investigated in a continuous flow fixed-bed micro-reactor. The used catalyst was characterized by means of XRD,pyridine-FTIR and TG. The effects of the NH3 content on the catalysts life and the methanol conversion were studied under the conditions of catalyst loading 10 g,atmospheric pressure,reaction temperature 480 ℃,WHSV of methanol 1.0 h-1,and mass ratio of water to methanol 0.69. It was showed that the NH3 content had no influence on the crystal structure of the ZSM-5 catalyst,but had an evident effect on its acidity. When the NH3 content was higher than 0.010%（w）,the total coking amount decreased evidently with increasing the NH3 content,which resulted in obvious shortening of the catalyst life.