Sustainable Production of Steel–Carbon Neutrality and Low Life Cycle Emission

Abstract

| Steel is most preferred and largest consumed engineering
material. It is also the largest contributor to greenhouse gas emissions.
Conventional steel production is highly carbon intensive and produces
about 2.2 tCO2 per tonne of steel produced. With predicted steel production growth of 25–30% by 2050, steel sector will be responsible for
the largest generation of anthropogenic emissions among the process
industries. Various steel-making process improvisations like Blast Furnace top gas recycling, usage of bio-mass, replacement of coke with
hydrogen for reduction, fuel change over to natural gas can drastically
bring down the emission levels of CO2. Serious thought is given towards
the reduction of CO2 emissions through CCS (CO2 Capture and Storage) and reutilization of caught carbon for chemical manufacturing.
Means of carbonless steel production using hydrogen generated from
renewable energy source are being considered to bring carbon neutrality to steel production by 2050. Steelmaking through the electrical arc
furnace using electricity from renewable sources is gaining popularity
considering the expected increase in scrap generation from 30 to 50%
and nearly zero carbon footprint. The further reduction of CO2 emission
during the lifetime of use of steel is expected through the usage of lightweight materials in automobiles which lowers the fuel consumption and
hence the lower CO2 generation. Various routes being explored to bring
CO2 emissions to a lower level of 0.4–0.5t CO2/t steel by enhancement of
existing production facilities and by the deployment of innovative methods are reviewed.