n-Nonane hydroisomerization over hierarchical SAPO-11-based catalysts with sodium dodecylbenzene sulfonate as a dispersant

• 作者: Cheng-Long Wen Jun-Dong Xu Xue-Man Wang Yu Fan
• 来源期刊: 石油科学（英文版）
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: PETROCHEMISTRY & CHEMICAL ENGINEERING
• 页码范围: 654-666
• 页数: 13页
• 语种: 英文

摘要

To enhance the gasoline octane number,low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization.Therefore,hierarchical SAPO-11-based catalysts are prepared by adding differ-ent contents of sodium dodecylbenzene sulfonate(SDBS),and they are applied in n-nonane hydroisomerization.When n(SDBS)/n(SiO2)is less than or equal to 0.125,the synthesized hierarchical molecular sieves are all pure SAPO-11,and as the SDBS content increases,the submicron particle size decreases,and the external surface area(ESA)increases.Addi-tionally,these hierarchical SAPO-11 have smaller submicron particles and higher ESA values than conventional SAPO-11.When n(SDBS)/n(SiO2)is greater than 0.125,with increasing SDBS content(n(SDBS)/n(SiO2)= 0.25),the synthe-sized SAPO-11 contains amorphous materials,which leads to a decline in the ESA;with the further increase in SDBS content(n(SDBS)/n(SiO2)= 0.5),the products are all amorphous materials.These results indicate that in the case of n(SDBS)/n(SiO2)= 0.125,the synthesized SAPO-11 molecular sieve(S-S3)has the most external Br?nsted acid centers and the highest ESA of these SAPO-11,and these advantages favor generation of the di-branched isomers in hydrocarbon hydroisomerization.Among these Pt/SAPO-11 catalysts,Pt/S-S3 displays the highest selectivity to entire isomers(83.4％),the highest selectivity to di-branched isomers(28.1％)and the minimum hydrocracking selectivity(15.7％)in n-nonane hydroisomerization.