CO2 utilization, a near-term survival potential for Indian steel

As befits, the Indian steel ministry has begun its work on Vision India@47 for creation of an environmentally responsible steel industry that promotes India’s economic growth and self-reliance. Being aspired by such an invigorating resolution, growing concerns about drawing down carbon dioxide levels in the atmosphere are intensifying interests in the Indian steel sector.

Technologically, steel is produced via two different process routes: the path from ‘iron ore to steel’ and the path from ‘scrap to steel’. With the iron ore-based route, oxygen contained in iron (oxide) ores is removed using carbon (mainly in the form of coke) in the blast furnace (BF); the liquid iron obtained through this process is subsequently refined in the basic oxygen furnace (BOF) to produce crude steel.

Another way to reduce ores into iron is via the direct reduction route; in this case, iron oxides are converted to metallic iron at temperatures below the melting point of iron. This solid-state process produces a product referred to as direct reduced iron (DRI). In India, as much as about 77% of the DRI is produced in coal-based rotary kilns.

With the scrap-based route, crude steel production occurs by melting steel scrap using electrical energy, either in an electric arc furnace (EAF) or an induction furnace (IF).

Most carbon dioxide emitted by the steel plants is associated with the use of carbon to convert iron ore to iron in the blast furnace. Even though steel production using an electric furnace is less carbon intensive, the limited load bearing capacities of the electric furnace route vis-à-vis recycled scrap scarcity puts restrictions in certain instances.