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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。
Butylene in HZSM-5 molecular sieve catalyst oligomerization, cracking and other reactions. In this paper, HZSM-5 molecular sieve was used as catalyst in isothermal fixed-bed reactor. The effects of reaction conditions such as space time, temperature and partial pressure on the oligomerization of butylene and the further cracking reaction of higher olefins were investigated. The experimental results show that increasing the space time can improve the conversion of butene, but it will aggravate the further cracking reaction of higher olefins and lead to the decrease of C_8 selectivity. In order to increase the selectivity of higher olefins, the space time should not be too high. (0.17kg · s / mol and 0.50kg · s / mol), the conversion of butenes first increases and then decreases with the increase of temperature (220 ~ 410 ℃), and reaches the maximum at 300 ℃. The experimental phenomenon in this article combined with the equation of butene consumption rate to explain. Under high temperature conditions, the higher olefins are further cracked to produce lower olefins, so the lower temperature is favorable for the oligomerization reaction to produce higher olefins. Increasing the partial pressure increases the reaction rate of butene consumption, which facilitates the oligomerization reaction to produce higher olefins. The reaction rate Partial pressure has a linear relationship.