Grant of the President of the Russian Federation № 075-15-2019-391
The project is aimed at developing an industrial technology of a multifunctional catalyst for the direct synthesis of winter and Arctic diesel fuel from synthesis gas. The implementation of the project made it possible to develop scientific foundations for the creation of strategically important industrial catalysts.
Polyfunctional catalysts were prepared by mixing powders of cobalt-containing catalyst (Co-Al2O3/SiO2), zeolite ZSM-5 and binder. The catalysts were tested in the synthesis of hydrocarbons from CO and H2 at a pressure of 2.0 MPa, a temperature of 240 ° C in a continuous mode for 50-120 hours. The influence of the calcination temperature of catalysts (from 350 to 550 ° C) on their activity and selectivity in the combined synthesis and hydroconversion of hydrocarbons has been studied.
It has been established that the optimal calcination temperature of the catalyst is 400 ° C, since the highest productivity for C5+ hydrocarbons and the highest content of iso-alkanes in the diesel fraction is achieved.
To reduce the content of unsaturated hydrocarbons in the fuel fractions, a hydrogenating component (Pt) was introduced into the catalyst in various ways. It was found that the introduction of a hydrogenating component (Pt) into the zeolite component of a multifunctional catalyst by the ZSM-5 zeolite ion exchange method reduces unsaturated hydrocarbons in synthetic oil by 2.5 times and increases the productivity of C5+ hydrocarbons by 26%. It is shown that the introduction of platinum into the catalyst leads to almost complete hydrogenation of unsaturated hydrocarbons in the diesel fraction. In the gasoline fraction, the proportion of unsaturated hydrocarbons decreased by 25% with the introduction of platinum by zeolite impregnation and by 33% with the introduction of platinum by zeolite ion exchange.
The resulting synthetic oil consists of 70% gasoline and 30% diesel fractions. The octane number of the gasoline fraction is 92, and the solidification temperature of the diesel fraction is minus 32 ° C.
For the optimal composition of the multifunctional catalyst, laboratory regulations have been developed, its enlarged batch (1 dm3) has been manufactured and tested. The physico-chemical and catalytic properties of the enlarged batch of polyfunctional catalyst almost completely coincide with the properties of previously prepared samples of a small volume catalyst (50 cm3).
The results obtained were used to develop technological regulations and manufacture a pilot batch (100 kg) of a multifunctional catalyst for the synthesis of high-octane gasoline and low-hardening diesel fuel in industrial conditions.