Abstract <p>The effect of CO₂ content in synthesis gas on the hydrocarbon synthesis–hydrotreatment combined procedure in the presence of a Co/SiO₂+ZSM-5+Al₂O₃ bifunctional catalyst was studied. The studies were conducted in a CO₂ content range of 0–60 vol % at temperatures of 240 and 250°C, a pressure of 2.0 MPa, and a GHSV of 1000 h⁻¹. It was that CO₂ can be partly converted to synthetic hydrocarbons in the presence of the bifunctional cobalt catalyst. The carbon dioxide added to synthesis gas undergoes conversion in a CO₂ concentration range of 20–40 vol %. The maximum CO₂ conversion is 5.3% at 240°C and 20 vol % of CO₂ in the gas. The addition of CO₂ to synthesis gas leads to an increase in the content of branched hydrocarbons in the Fischer–Tropsch synthesis products. These hydrocarbons contribute to an improvement in the detonation resistance of gasoline and the low-temperature properties of the diesel fraction (cloud point, cold filter plugging point).</p>