Simulation and multi-objective optimization of liquid hydrocarbons production by coupling Blast-Furnace Gas with Coke-Oven Gas of steelwork

Steelwork is one of the main CO₂ emitters due to three main off-gases of Blast-Furnace Gas, Coke-Oven Gas, and Basic Oxygen Furnace Gas. Many efforts are being made to reduce CO₂ emissions by unit optimizing or by carbon capture and storage processes. In this paper, the simulation of Blast-Furnace Gas and Coke-Oven Gas recovery is investigated using Aspen HYSYS. For this purpose, a part of the Blast-Furnace Gas gases is mixed with the Coke-Oven Gas and injected into the Fischer-Tropsch reactor to produce liquid hydrocarbons. The process has been optimized by response surface methodology using Design Expert. The optimized simulation results showed that by mixing a portion of Blast-Furnace Gas and Coke-Oven Gas, the syngas was provided without fuel consumption in the reforming unit in both the reactor and utility system while C₅⁺ and C₂-C₄ were produced by 219Mbbl/day and 380Mbbl/day. At the same time, CO₂ emissions decreased by 51%.