Home – Home – Jornals – Chemistry for Sustainable Development 2025 number 2

A catalyst for the process of upgrading the straight-run gasoline fraction of oil was developed on the basis of pentasil zeolite by means of postsynthetic alkaline treatment, followed by the introduction of nanosized nickel powder. Three reaction-regeneration cycles were carried out, textural, acidic and catalytic properties of the initial and regenerated samples were studied, the amount of carbon compaction products and temperature range of their removal were determined. It is shown by IR spectroscopy that triplicate regeneration of carbonised zeolite catalysts does not change their crystal structure. It is shown by low-temperature nitrogen adsorption that multiple regenerations of the catalyst lead to an insignificant decrease in total specific surface area and total specific pore volume, with an increase in the specific surface area of mesopores. The temperature-programmed desorption of ammonia has been used to determine that the strength and concentration of acid sites in the regenerated samples decreased significantly, compared to the initial zeolite, only after the third regeneration. The activity of initial zeolite catalyst and its regenerated forms has been studied in processing the straight-run gasoline fraction of oil by the flow method in a reactor with a fixed catalyst bed, without using hydrogen-containing gas, at atmospheric pressure. It has been shown that after each reaction-regeneration cycle, the catalytic activity decreases slightly, but at the same time, the octane numbers of the resulting gasolines remain fairly high, and the yield of the catalysates increases. Using differential thermal analysis, it was determined that the number of regenerations has almost no effect on the amount of carbon compaction products on zeolite catalysts, as well as on the temperatures of decomposition peaks and termination of coke removal, but slightly reduces the temperature at which carbon deposits begin to burn out.