丁烯在HZSM-5催化剂上齐聚反应的工艺条件

Effects of operational conditions on butene oligomerization over HZSM-5

丁烯在HZSM-5分子筛催化剂上发生齐聚、裂化等反应。本文在等温固定床反应器中以HZSM-5分子筛为催化剂,考察并研究了空时、温度和分压等反应条件对丁烯齐聚反应以及高碳烯烃进一步裂化反应的影响。实验结果表明,增大空时可提高丁烯转化率,但会加剧高碳烯烃的进一步裂化反应并导致C_8的选择性降低;为提高高碳烯烃的选择性,空时不应过高;当空时为0.17kg·s/mol和0.50kg·s/mol时,随温度（220~410℃）的升高丁烯转化率先增大后减少,在300℃时转化率达到最大值。对此实验现象本文中结合丁烯消耗速率方程做出了解释。高温条件下高碳烯烃进一步裂化生成低碳烯烃,因此低温则有利于齐聚反应生成高碳烯烃;提高分压增大丁烯消耗反应速率,有利于齐聚反应生成高碳烯烃,反应速率与分压有线性关系。

The oligomerization and cracking of 1-butene were studied at various space-time,temperature and partial pressure and over HZSM-5 in an isotherm fixed-bed reactor. The results showed that increasing the space-time could improve the catalyst activity,but increased the cracking reaction and lowered the selectivity of C_8. When the temperature was increased from 220℃ to 410℃,the conversion of 1-butene increased first but then decreased,and the highest conversion of 1-butene was obtained at 300℃ which was explained by the 1-butene consumption rate equation. 1-Butene oligomerization was in favor of low temperature. At higher temperature cracking increased rapidly,resulting in the product distribution shifted towards lighter hydrocarbons. It was also observed that higher partial pressure increased the consumption rate of 1-butene,and therefore the oligomerization favored high partial pressure.