加氢异构催化剂性质对长链烷烃异构行为的影响

Effects of Catalysts on Catalytic Performance in Long Chain n-Alkanes Isomerization

在微反实验装置上分别考察了以一维十元环孔道结构的分子筛ZIP-1和BCM-168为酸性组分制备的加氢异构催化剂对正十六烷异构行为的影响规律;以费-托合成蜡为原料,在中型试验装置上对微反实验结果进行验证。结果表明,在相同的转化率下,以BCM-168作为酸性组分的催化剂异构选择性较好,异构烃收率较高,且在单支链异构体中,甲基支链更多地位于碳链中部。催化剂的孔径和酸性是造成这种现象差异的原因,较大的孔径有利于形成多支链异构烃;弱酸性使得高转化率下的裂化作用相对较弱,有效提高了异构烃收率和选择性。中型试验结果对微反实验的结论进行了证实,在相同的工艺条件下,在以BCM-168分子筛为酸性组分制备的催化剂作用下基础油产品收率更高。

Catalytic performance over two hydroisomerization catalysts respectively containing acidic component of ZIP-1 and BCM-168 zeolites with one-dimensional and ten-rings pore were investigated using n-hexadecane as model molecular on a microreactor,and this was verified over a pilot plant by using Fischer-Tropsch synthetic wax.Results show that,under the same conversion,the acidic BCM-168 based catalyst is of higher isomerization selectivity,thus with higher yield of isomers than that of ZIP-1 based catalyst.Moreover,with respect to single branched isomers,the methyl branched chain is majorly located in the middle of the carbon chain.It is attributed to the differences in the pore size and acidity of catalysts,and larger pore size is beneficial to the formation of multi-branched isomers.Weak acidity of the BCM-168 based catalyst weakens catalytic cracking reaction under high conversion,hence improving the yield and selectivity of isomers.The pilot plant test result agrees well that of model molecule experiments,with BCM-168 based catalyst showing higher lube base oil yield under the same process conditions.