Thermocatalitic Conversion of n-Heptane and the Gas Condensate on Cuprum-Containing Zeolite Type ZSM-5

Abstract

The effect of zinc concentration and conditions of thermocouple treatment on the acid and catalytic properties of zeolite ZSM-5 in the thermocatalytic conversion of nheptane and gas condensate was studied with the aim of obtaining lower C2-C4 alkenes. It is shown that the composition of the products of the thermal catalytic conversion of nheptane depends on the concentration of copper in HZSM-5. The introduction of HZSM-5 copper in an amount of up to 1.0 wt.% leads to a significant increase in the yield of alkenes and a decrease in the content of aromatic hydrocarbons. A further increase in the concentration of copper to 3.0 wt.%. In the zeolite helps reduce the yield of C2-C4 alkenes and increase its aromatizing activity. It is shown that the conditions of thermocouple treatment significantly affect the acidic and catalytic properties of 1% Cu-HZSM-5 catalyst in the conversion of gas condensate to lower C2-C4 olefins. Thermocouple treatment of 1% Cu-HZSM-5 at 650-700 0 С for 180 minutes leads to an increase in the yield of alkenes from 40.2 wt.% to 50.8 wt.% and a decrease in the content of aromatic hydrocarbons from 58.5 to 16.9 wt.%. The modifying effect of copper and TСТ on the activity and selectivity of catalysts is due to a change in their acid spectrum caused by zeolite de-illumination and the ratio of Brenstod and Lewis acid centers. Indeed, as can be seen from Table 2, TСТ of samples reduces the total concentration and strength of acid centers, and first, a decrease in the concentration of strongly acidic centers is observed.On samples of 1% Cu -HZSM-5 subjected to TСТ, there is a general tendency to reduce the degree of conversion of gas condensate and reduce the formation of aromatic hydrocarbons, which is associated with a decrease in the concentration of strongly acidic centers. On all samples of 1% Cu -HZSM-5 subjected to TСТ at different conditions, an Thermocatalitic ….