Production of synthetic diesel fuel by the Fischer–Tropsch (FT) method in the presence of a composite catalyst prepared by mechanically mixing 35 wt % Co/SiO2, 30 wt % HZSM-5, and 30 wt % Al2O3has...

The paper presents a review of modern industrial and competitive experimental approaches to gas-to-liquid (GTL) and polyalphaolefin (PAO) oil technologies for the production of synthetic base oils. The key aspects of the synthesis of environmentally friendly isoparaffin and PAO base oils are discussed: the feedstocks, process designs, and catalysts. Based on an analysis of relevant scientific and engineering advances reported to date, the current trends of synthetic base oil technologies are shown, including the creation of novel high-performance homogeneous and heterogeneous catalysts, as well as the prospects for the Fischer-Tropsch process and the GTL technology in general for the production of isoparaffin oils (including those with improved low-temperature properties) and of synthetic PAO oil components.

The formation of silicoaluminophosphate gels using boehmite, Al isopropoxide, and di-n-propylamine as a template of silicoaluminophosphate gels as well as their subsequent crystallization into SAPO-11 molecular sieves was studied in detail using X-ray fluorescence spectroscopy (XRF), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N₂ adsorption–desorption methods. The effect of the chemical and phase composition of silicoaluminophosphate gels on the physicochemical properties of SAPO-11 molecular sieves was shown. The secondary structural units that the AEL lattice is composed of were found to be formed at the initial stage of preparation involving aluminum isopropoxide. Several approaches to control their morphology and secondary porous structure are also proposed.

The results of the working stability studies of cobalt catalysts based on SiO₂ and Al₂O₃ promoted with Re and Al₂O₃ in the synthesis of hydrocarbons from CO and H₂ in continuous tests for 200–300 h are presented. The prepared catalysts were characterized by transmission electron spectroscopy, temperature-programmed reduction with hydrogen, temperature-programmed desorption of CO, and X-ray fluorescence spectroscopy and tested at a temperature 200°C, a pressure of 0.1 MPa, and a GHSV of 100 h^–1. It was determined that a cobalt–silica catalyst promoted with Al₂O₃ had the highest activity. It was established that the addition of Al₂O₃ to a cobalt–silica catalyst increased the conversion of CO and selectivity for C₅₊ hydrocarbons and inhibited the agglomeration of Co particles under the action of a reaction atmosphere in the Fischer–Tropsch synthesis. It was found that the initial conversion of CO increased by a factor of 2 upon the introduction of 0.1 wt % rhenium into the Co/γ-Al₂O₃ catalyst; however, the rate of its deactivation increased in this case due to an almost twofold increase in the size of cobalt particles in the course of synthesis after operation for 300 h.

The effects of the H2/CO ratio, pressure, temperature, and the reaction-gas recycle ratio on the selectivity for hydrocarbons (HCs), including long-chain C35+ HCs, in the Fischer–Tropsch synthesis ove