Abstract:

The thermal cracking and catalytic cracking reaction performance of C₅ alkanes were investigated, and the cracking reaction products of n-pentane and isopentane were found to be different. Furthermore, the pyrolysis mechanism of n-pentane and isopentane was analyzed, and the difference between the cracking of n-pentane and isopentane to produce light olefins and methane was revealed. The results showed that under thermal pyrolysis conditions, the selectivity of (ethylene + propylene) of n-pentane was higher than that of isopentane, the selectivities of isopentane thermal pyrolysis products butene and methane were higher than that of n-pentane. At 650℃, the selectivities of n-pentane and isopentane thermal pyrolysis products including (ethylene + propylene), butene, and methane were 37.48%, 7.23%, 6.75% and 19.57%, 25.16%, 9.36%, respectively. However, under catalytic pyrolysis conditions, the selectivities of isopentane catalytic pyrolysis products (ethylene + propylene), butene, and methane were higher than that of n-pentane. At 650℃, the selectivities of n-pentane and isopentane thermal pyrolysis products including (ethylene + propylene), butene, and methane were 37.16%, 9.11%, 7.80% and 47.70%, 14.45%, 13.79%, respectively. In addition, it was found that isoalkanes are easier to crack to butene and methane than n-alkanes under high temperature cracking conditions.

Key words: alkane, catalytic pyrolysis, pyrolysis, light olefins, methane

摘要：

考察了碳五烷烃的热裂解和催化裂解反应性能，发现正戊烷和异戊烷的裂解反应产物存在差异；进一步分析了正戊烷和异戊烷的裂解反应机理，以及裂解生成低碳烯烃和甲烷的区别。结果表明，在热裂解条件下，正戊烷的（乙烯+丙烯）选择性高于异戊烷，异戊烷的丁烯和甲烷选择性高于正戊烷；650℃时，正戊烷和异戊烷的热裂解产品中（乙烯+丙烯）、丁烯、甲烷的选择性分别为37.48%、7.23%、6.75%和19.57%、25.16%、9.36%。而在催化裂解条件下，异戊烷的（乙烯+丙烯）、丁烯、甲烷选择性均高于正戊烷；650℃时，正戊烷和异戊烷的催化裂解产品中（乙烯+丙烯）、丁烯、甲烷的选择性分别为37.16%、9.11%、7.80%和47.70%、14.45%、13.79%。此外，发现在高温裂解条件下异构烷烃比正构烷烃容易裂解生成丁烯和甲烷。

关键词: 烷烃, 催化裂解, 热解, 低碳烯烃, 甲烷