The Effect of Modification Method of ZSM-5 Zeolite with Zinc on the Product Composition in Cracking of Hydrocarbon Feedstock

• Published in: Petroleum chemistry 2022-08, Vol.62 (8), p.862-869
• Main Authors: Yurtaeva, A. S., Potapenko, O. V., Bobkova, T. V., Gulyaeva, T. I.
• Format: Article
• Language: English
• Subjects: Additives; Aromatic hydrocarbons; Catalytic activity; Catalytic cracking; Chemistry; Chemistry and Materials Science; Gas oil; Gasoline; Hydrocarbons; Impregnation; Industrial Chemistry/Chemical Engineering; Ion exchange; Methods; Parameters; Zeolites; Zinc
• ISSN: 0965-5441; 1555-6239
• DOI: 10.1134/S0965544122070222

The influence of the zinc incorporation method (ion exchange, impregnation) and its content (from 0.25 to 0.75 wt %) in ZSM-5 zeolite on the physicochemical characteristics of the zeolite (textural parameters, concentration of acid sites) and on the catalytic activity of cracking catalysts with the additives containing the modified zeolites in transformations of hydrotreated vacuum gasoil was studied. The zinc introduction by impregnation leads to a slight decrease in the zeolite specific surface area and micropore volume from 420 to 380 m 2 /g and from 0.131 to 0.117 cm 3 /g, respectively, and the total concentration of acid sites at the maximal zinc content increases by 17% compared to unmodified ZSM-5. Modification of the zeolite samples with zinc by ion exchange does not alter the main pore structure parameters compared to the initial zeolite, whereas the acid site concentration reaches the highest values (up to 2025 μmol/g). With an increase in the zinc content of ZSM-5 zeolite, with both modification methods (ion exchange, impregnation), the yield of the gasoline fraction and aromatic hydrocarbons in liquid products of cracking of hydrotreated vacuum gasoil increases.