ZRP沸石对FCC汽油催化裂解产丙烯的影响

研究了在550℃、常压、加入水蒸气条件下,FCC汽油在ZRP沸石上的催化裂解反应和ZRP沸石硅/铝比(n(SiO2)/n(Al2O3))变化及稀土改性ZRP对反应的影响。实验结果和反应前后反应物与产物分布的计算结果表明,FCC汽油中烯烃进行裂化反应生成丙烯。提高烯烃的选择性转化、促进裂化反应并提高丙烯产物的选择性,有利于提高丙烯产率。提高ZRP沸石的n(SiO2)/n(Al2O3)能够增加其强酸量,使烯烃的转化率和低碳烯烃的选择性有所提高,但丁烯选择性高于丙烯的选择性。采用稀土改性也可使ZRP沸石增加强酸量,提高烯烃的转化率和丙烯的选择性,使74.32%的烯烃被转化,裂解汽油烯烃质量分数为18.20%,丙烯选择性达到45.91%。

Study on Aromatization of C_6 Aliphatic Hydrocarbons on ZRP Zeolite Catalyst

The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.