Pt/SAPO-11催化剂载体的改性对正十四烷临氢转化性能的影响

以Pt/SAPO-11双功能催化剂为基础,对催化剂载体进行柠檬酸、炭黑改性,以正十四烷为模型化合物,通过催化剂表征和反应评价,探索了催化剂载体的改性对正十四烷临氢转化性能的影响。结果表明,异构化产物以单甲基异构物为主,改性没有改变催化剂的酸强度,但使得酸浓度有所下降。通过柠檬酸调变催化剂的酸性使得催化剂的低温催化活性显著提高,采用炭黑扩孔改性,有效改善了催化剂的传质性能,提高了催化剂的单甲基异构体选择性。柠檬酸和炭黑改性的催化剂裂化产物均以C6为主,改性并没有改变SAPO-11分子筛的孔道限制效应,裂化产物呈现一定的择型效应,裂化产物分布呈现出不对称分布的特点。

Study on the transformation rule of n-tetradecane hydroisomerization over modified Pt/SAPO-11 catalyst

Pt/SAPO-11 bifunctional catalyst was modified with citric acid and carbon black. The effects of different modified methods on the catalytic activity of Pt/SAPO-11 catalysts were investigated using n-tetradecane as the probe reaction.Results indicated that the isomerization products were mainly composed of monomethyl isomer, the modification has not changed the acid strength of the catalyst, but the acid concentration has decreased. The citric acid significantly improved the low temperature catalytic activity of the catalysts, while carbon black effectively promoted the mass transfer performance and monomethyl isomer selectivity of the catalysts.The cracking products were mainly composed of C₆ compounds, and modification did not change the shape selective effects of SAPO-11 molecular sieve. Carbon number distribution of cracking products was obvious asymmetric distribution.