Sponge iron kilns are energy intensive. 30% of the energy input to the kiln is lost to the atmosphere through flue gas. Many sponge iron plants with kiln capacity higher than 200 tons, the heat in the exhaust flue gas is already utilised to generate steam and generate power. However, sponge iron plants with a capacity less than 200 tons normally let out the flue gas into the atmosphere after cooling the same in forced draft cooler(FDC). Hence there is a great oppurtunity for these plants to install ORC power systems for conversion of waste-heat to power.
As per conservative estimates, it is possible to generate upto 1.5MW electrical power from the waste flue gas emnating from a 200 ton sponge iron kiln.
energy input to kiln is lost through flue gas
let out the flue gas into the atmosphere after cooling
electrical power from the waste flue gas