One of the world’s largest steelmakers has deployed a novel heat battery at its plant in India to curb emissions from its dirty, energy-intensive operations.
Tata Steel is using the 20-megawatt-hour thermal-storage system, developed by the German startup Kraftblock, at a massive steel mill in Jamshedpur, in the eastern state of Jharkhand. The technology captures waste heat that’s generated during an early stage of the steelmaking process, then repurposes that heat to replace fossil gas used within the plant.
On Friday, the companies announced the project for the first time and shared the initial results. Kraftblock has been operating the heat battery since last May as part of a one-year test run with Tata Steel.
Based on how well the system has performed so far, the cleantech firm expects its thermal-storage technology will reduce the site’s carbon dioxide emissions by 22,000 metric tons per year — about the same as taking 5,100 gas-fueled cars off the road — and will eliminate about 110 gigawatt-hours of fossil-gas use per year.
“It’s performing better than we calculated,” Martin Schichtel, Kraftblock’s CEO and co-founder, told Canary Media.
The project is likely the first of its kind within the steel industry, experts say. But manufacturers in other industrial sectors are increasingly testing out thermal-storage technology as they look for cleaner ways to produce the scorching heat they need to make ceramics, chemicals, dairy products, and processed food and drinks.
Some of these systems draw electricity from the grid to generate and store heat in specialized bricks, rocks, or salt. They then supply that heat to industrial furnaces and boilers whenever companies need it. Kraftblock, which launched in 2014, operates a system like this at a PepsiCo factory in the Netherlands, where heat batteries are used instead of fossil gas to deliver steam and hot oil for frying potato chips. The company has developed a “stonelike” storage material from byproducts such as steel slag and copper-mine waste, Schichtel said.
Kraftblock’s system in India charges up using the excess heat from industrial processes, not electricity. Schichtel said that hard-to-decarbonize sectors like steelmaking have a “huge” potential to harness more of their waste heat, which is typically just lost to the air.
At the Tata Steel site, two Kraftblock units are connected to the “sinter” plant by a maze of thick silver pipes. Sintering is a highly energy-intensive process in which iron ore, limestone, and other materials are heated together to make lumps that are fed into blast furnaces — the hulking coal-fueled facilities that produce iron, the main ingredient in steel.
Tata Steel primarily uses fossil gas to generate heat to make the sinter, and later runs the finished product through large circular equipment to cool it back down. Kraftblock’s technology gathers the thermal energy that the cooled-off sinter releases and stores it in the batteries — at up to 500 degrees Celsius (932 degrees Fahrenheit). Tata Steel can then tap those batteries to warm the water needed for the sintering process.
Kraftblock’s system “enables us to significantly reduce our fossil energy consumption and emissions while improving process efficiency,” Subodh Pandey, Tata Steel’s vice president of technology, R&D, new materials business, and graphene, said in a statement to Canary Media. “This project is a significant step towards a greener, more energy and cost-efficient steel industry.”
Kraftblock declined to say how much its 20-MWh system cost to build or operate. But Schichtel said the project was developed without any subsidies, a fact that reflects the growing regulatory pressure facing Indian steelmakers. India is set to launch a carbon-credit trading scheme this year, and the European Union recently enacted a carbon-border tariff on polluting imports, which applies to metal from India.
Great Job Maria Gallucci & the Team @ Canary Media for sharing this story.
