1-己烯和正己烷混合烃在不同分子筛催化剂作用下的裂化产物分布规律

PRODUCT DISTRIBUTION OF MIXTURE OF 1-HEXENE AND n-HEXANE OVER DIFFERENT ZEOLITE CATALYSTS

以1-己烯和正己烷不同质量配比的混合烃(以1-己烯质量分数计)为模型化合物,考察在4种分子筛催化剂(ZRP-L,Beta-L,REY-L,DASY-L)作用下混合烃的裂化产物分布规律,分别计算了1-己烯在4种分子筛催化剂作用下对正己烷转化的贡献因子,阐述了不同分子筛催化剂下不同质量配比模型化合物对烯烃、烷烃、异构烃类以及芳烃选择性的影响。结果表明:在同种催化剂作用下,随着模型化合物中1-己烯含量的增加,烷烃和烯烃选择性呈现相反的变化趋势,反应具有竞争性;在4种催化剂作用下,随着1-己烯含量的增加,异构产物选择性均增加,增加幅度由大到小对应的催化剂依次为DASY-L≈REY-L>Beta-L>ZRP-L,与4种催化剂孔径大小有良好对应关系;在4种催化剂作用下的芳烃选择性均较低,模型化合物中1-己烯促进了芳构化反应的进行,芳烃选择性与催化剂酸量及酸强度有关,催化剂酸量越高、酸强度越小,芳烃选择性越高。

The cracking tests of the mixtures of 1-hexene and n-hexane with different mass ratio(based on 1-hexane mass fraction)on ZRP,Beta,DASY and REY zeolite catalysts were carried out in a fixed fluidized bed reactor at 500℃to investigate the rule of cracking products distribution.The contribution factors of 1-hexene to n-hexane conversion on four zeolite catalysts were calculated,and the effects of different mass ratios of model compounds on the selectivity of olefins,alkanes,isomeric hydrocarbons and aromatics were expounded.The results showed that on the same catalyst,with the increase of 1-hexene content in the model compound,the selectivity of alkanes and olefins showed an opposite trend,indicating the reaction is competitive.The selectivity of isomerization products on the four catalysts increased as the 1-hexene n-hexane ratio increased,and the order of the selectivity was DASY-L≈REY-L>Beta-L>ZRP-L,which has a good corresponding relationship with the pore size of the four catalysts.1-Hexene in the model compound promoted the aromatization reaction,but the aromatics selectivities of the four catalysts were low.The results showed that the selectivity of aromatics is related to the acid amount and strength of catalyst.The higher the acid amount is and the smaller the acid strength is,the higher the selectivity of aromatics is.