The steel industry has had an image problem. According to recent data, steel makers generate some 40% of global CO2 emissions and represent a third of global energy demand. American steel manufacturers alone generate 1.8 tons of carbon dioxide per each ton of crude steel they make.
But engineers at GE Energy have found a way to turn some of steel’s biggest liabilities into assets. Through innovation, they have improved on an old method to convert carbon and hydrogen-rich waste greenhouse gases into electricity. Last week they announced their latest order, for a new 170-megawatt power plant at Handan Iron & Steel‘s mill in Handan City, China.
The project will capture, clean and compress the blast-furnace (BFG) and coke oven gases (COG) generated during the steel making process and feed it to GE’s giant 9E Heavy-Duty Gas Turbine. The technology will produce enough electricity to potentially turn an average-size steel mill into a net power generator. “The plant can go from being a parasitic facility to essentially a utility,” says GE Energy’s Ryan Derouin. “If they are in that utility-island mode, they can start selling power back to the grid or send it to other parts of the plant. It gives the owner options.”
Derouin says that technology has the potential to halve the electricity cost for Handan, from the market rate of $100 per megawatt to as low $60 per megawatt. It allows the mill to lower costs, boost profitability, and gain a competitive edge, especially in a market with low grid reliability.
The waste gases at Handan vary in quality and contain too little of the heat packing hydrogen to make the gases burn effectively by themselves.
However, GE engineers found a clever way to clean, compress and mix the gases to power the huge turbine. “This is the lowest quality fuel we’ve ever even considered burning,” said Keiran Coulton, president of GE Energy, Global Industries. “But we saw the potential to redesign the fuel instead of re-designing the plant.”
This is not the first such project in China. In 2010, GE rolled out two GE 9E turbines at Wuhan Iron & Steel. So far, the turbines have increased Wuhan’s energy efficiency by 25-40% on average and lowered emissions by about 2 million tons of CO2.
China’s new laws and tighter environmental regulations will benefit early clean tech adopters. “We are not simply doing the same things better,” says Handan’s General Director Li Fujun. “We’re doing something completely new. And that will have a huge impact on our efficiency, energy costs, and carbon footprint.”