Bizeolite Pt/ZSM-5:ZSM-12/Al2O3 catalyst for hydroisomerization of C-8 fraction with various ethylbenzene content

Effect of use of methyltriethylamonium chloride individually and combined with n-butylamine on the characteristics of the ZSM-12 zeolite crystallization process

“…Due to these structural characteristics, ZSM-12 has a high shape selectivity in obtaining sterically unimpeded linear molecules (Kulikov et al, 2019). Particularly, ZSM-12 is used as catalyst in the selective production of p-xylene (Glotov et al, 2021), 2,6-dimethylnaphthalene (Li et al, 2011), p-tert-butylphenol (Li et al, 2014), 4,4'-diisopropylbiphenyl (Chokkalingam et al, 2013, in the cracking (Sanhoob et al, 2018) and hydrocracking of hydrocarbons (Mehla et al, 2013).…”

Novel Composite Catalysts Efficiently Catalyze C8 Aromatics by Controlling the Reaction Pathway

“…3 Currently, industrial xylene isomerization catalysts are mainly prepared based on zeolite. 3,7,8 Zeolite has the advantages of high stability, high specific surface area, abundant pores, and acid sites density. 9−13 It is worth mentioning that the ZSM-5 zeolite has three-dimensional pores (5.1 Å × 5.5 Å and 5.3 Å × 5.6 Å) close to the dynamic diameter of PX, which are smaller than MX and OX.…”

“…This indicates that these catalysts have acidic sites of different intensities. 7,39,40 Significantly, parent Z20 (Si/ Al = 20) has the highest acid content and ammonia desorption temperature mainly due to its low Si/Al ratio. 16,41 It is obvious that both the weak acid and strong acid contents of the Pt-3Si/ Z20 catalyst are significantly reduced (Figure 4 and Table S3).…”

“…The dealkylation of EB in the C8 fraction to benzene is currently the most effective method. , The conversion of EB to benzene and ethylene during xylene isomerization can effectively prevent the accumulation of EB in the recycle loop. When xylene reaches thermodynamic equilibrium, it is optimal to obtain high EB conversion and low xylene loss at the same time. ,, The isomerization process of C8 aromatics includes the isomerization of xylene and the dealkylation of EB. The isomerization of C8 aromatics is mainly an acid-catalyzed reaction .…”

“…The isomerization of C8 aromatics is mainly an acid-catalyzed reaction . Currently, industrial xylene isomerization catalysts are mainly prepared based on zeolite. ,, Zeolite has the advantages of high stability, high specific surface area, abundant pores, and acid sites density. − It is worth mentioning that the ZSM-5 zeolite has three-dimensional pores (5.1 Å × 5.5 Å and 5.3 Å × 5.6 Å) close to the dynamic diameter of PX, which are smaller than MX and OX. , Therefore, ZSM-5 has high shape selectivity and provides a high p -xylene/ o -xylene ratio in the xylene isomerization reaction …”