Sustainability analysis of the use of natural gas in the iron and steel industry

In this study, using natural gas instead of coke gas in the reheating furnace in a steelmaking company is investigated in terms of economic, social, and environmental impacts. A sample projection is prepared, and economic analyses are conducted in line with the production plan target for future planning periods of 144 months. The natural gas usage increases the production quantity by 914 tonnes and allows the company to produce 5,979,334 kWh of additional electric power from the metallurgical gases monthly. In the economic analysis, we use engineering economics techniques to examine the economic impacts of the modernization investment for reheating furnaces. Accordingly, a positive return for each month shows the feasibility of the renovation project. The self-paying time of the investment is calculated as a short period of 11 months. Besides, the social and environmental impacts are notable; the renovation project decreases occupational health and safety risks by using natural gas as a substitute fuel, preventing a potential explosion or poisoning risk in the production, storage, and distribution. The renovation project decreases the global warming potential of blast furnace gas constituents and carbon emissions by 0.84% per month.