Green Steel

 

Environment management has been a priority area for JSPL. We have been treading the difficult path of maintain our profitability without compromising on our efforts to reduce environmental impact. Through our innovations we have proved that environmental conservation and profitability is not an oxymoron if we apply innovation. The case study presented below proves the same.

Background

Direct-reduced iron (DRI), more commonly known as sponge iron, is produced from direct reduction of iron (in the form of lump, pellets or fines) by reducing gases produced from natural gas or coal. This reduction takes place at the temperature range 800- 1050C when reducing gases (primarily Hydrogen and Carbon-monoxide) react with the iron oxides to produce iron. The degree of metallization, defined as the extent of conversion of iron oxide into metallic iron, is 92-96% in a typical DRI process. This high percentage of metallization makes DRI a highly suitable input for steel making. The specific investment and operating costs of DRI plants are low compared to integrated steel plants and are more suitable for many developing countries where supplies of coking coal are limited. This holds true for India where most of the coking coal has to be imported.

Challenge

Natural Gas based DRI is highly efficient techniques of manufacturing sponge iron that has lower environmental impact. However, the challenge in this manufacturing technique is the availability of natural gas. At JSPL’s Angul site, the DRI-BF- Electric Arc Furnace route has been adopted for manufacturing steel. To overcome the challenge of non-availability of natural gas Coal to gas plant was set up. It uses high ash coal, available in the vicinity of the site, and converts it into Synthetic Gas or SynGas. It is the first plant of its kind in India and only the 2nd in the world.

Our Solution

At Angul, the Syngas, produced through the gasification process, contains methane, carbon monoxide, carbon dioxide, hydrogen and water vapour from coal, water and air. This process has lower impact on environment as compared to coal combustion process. During the gasification process, the carbon-dioxide emitted in the process is entirely absorbed back into the process and the hydrogen sulphide produced is entirely used for sulphur production.
Capital expenditure of setting up of the Syngas plant was high and had a gestation period of three years. However, this high investment is offset by the improved energy efficiency of the system, as compared to the conventional model of producing steel, and reduced environment impact in the long run. Another added advantage which we able to explore was the utilization of waste. All seven by-products of the Syngas plant are recycled through internal use or sold to external parties. This ensures health and safety of employees as well as local communities and environmental protection.