Intelligent Energy

How to fix steel's bad chemistry

How to fix steel's bad chemistry

Posting in Energy

Tata Steel and mining giant Rio Tinto team up to develop a process that cuts carbon-belching coke from the steel making formula. Will it help reduce the industry's huge greenhouse gas footprint?

When it comes to C02 emissions, steel making has a fundamental problem: the industry uses coke as a raw material. Throw the lumpy grey stuff into a blast furnace, mix it with iron ore and limestone, and out comes liquid iron, ready to morph into steel.

Coke itself typically comes from an energy intensive conversion of coal, and we all know the connection between coal and CO2.

Thus the steel industry takes a dubious place among carbon culprits. It contributes 8% of the world’s carbon emissions, according to consultants McKinsey. Not all of that is from the blast furnace – some comes from transport and other aspects of the supply chain – but you get the picture.

To its credit, steel has made impressive environmental strides. It recycles like crazy - about 30% of all steel comes from scrap. And it is continually producing stronger and lighter steel that helps the automobile and building industries chip away at their own carbon emissions.

But the steel’s ultimate environmental goal is to eliminate coke and coal from the manufacturing process.

“The Holy Grail is to get away from the use of carbon-based material in the production of iron,” says Ian Goldsmith, European director of public affairs for $26.6 billion Mumbai-based steel maker Tata Steel.

Or, as Michel Wurth, group management board member for $78 billion, Luxembourg-based steel maker ArcelorMittal puts it, the long term aim is to “change the whole chemical process” of steel making.

“We need a totally new process to further reduce the carbon footprint of steelmaking,” agrees Gunnar Still, senior vice president of $60.3 billion German steelmaker ThyssenKrupp.

The problem with deploying whole new processes in an industry as large as steel is that it can take, shall we say, as long as it does to fossilize plants into coal. Various ideas are germinating. Steel companies in Europe, the U.S., Japan and S. Korea are loosely collaborating to replace carbon fuels with other sources, including hydrogen and electrolysis. But the estimated time scales for completing these range from an optimistic 10 years, to 40 years.

Meanwhile, several initiatives are under way to reduce CO2 emissions during the production of new steel.

Most recently, Tata Steel and $60.3 billion Anglo Australian mining giant Rio Tinto agreed to commercial terms under which they will jointly develop a process that allows producers to feed coal directly into a furnace, rather than first converting it to coke, thus cutting energy requirements. The direct coal method comes from Tata, which calls it “cyclone pre-reduction.”

Rio Tinto’s contribution: a smelting process that permits common, sand- sized iron ore called “fines” to go straight into a furnace – probably not a blast furnace. This eliminates the energy intensive process of first “sintering’ the fines into lumps. And fines are also cheaper than lumps, so a reinforcing circle emerges of lower cost and less carbon.

Tata and Rio call the process Hisarna, which combines Rio Tinto’s “hismelt” technology and “isarna,” the Celtic word for iron. They are firing up a small Hisarna trial at Tata’s massive IJmuiden works (pictured) in Holland, at the mouth of the North Sea Canal. The trial will produce about 60,000 tons per year, which is just a dot of IJmuiden’s 7 million tons per year capacity.

While they have been planning Hisarana for some time, they only recently agreed licensing terms that define how they’ll share technology between themselves and other producers. They did not reveal the terms.

Tata and Rio believe that Hisarna will reduce energy requirements and carbon emissions by at least 20%. The figure grows as high as 80% if a steel maker then captures and buries the carbon.

The HIsarna pilot plant represents a potentially key step towards a compact and low-cost ironmaking process with a significantly reduced environmental impact,” Tata Steel’s CEO for Europe Karl-Ulrich Köhler said in a joint press release with Rio.

“This combination offers excellent opportunities for the collection and geological storage of CO2, the ability to utilise lower-cost raw material feeds, and the prospect of energy savings through the elimination of stages in the ironmaking process that are necessary today,” the release stated. “The technology has the long-term potential to replace conventional blast furnaces, coke ovens and sinter plants and to reduce CO2 emissions by more than 50% if combined with Carbon Capture and Storage (CCS).”

Hisarna is one of at least two initiatives under development at a European consortium called ULCOS – Ultra-Low Carbon Dioxide Steelmaking - which in turn works with steel makers around the world through the Brussels-based World Steel Association’s (worldsteel) CO2 Breakthrough Program. ULCOS is co-funding Hisarna, as is the European Commission and the Dutch government.

Another ULCOS project, led by ArcelorMittal – the world’s biggest steel maker – captures waste gases, including CO2. The technology plan, called Top Gas Recycling, calls for storing the CO2 underground or undersea, and for re-injecting carbon monoxide along with pure oxygen into the blast furnace, improving the furnace’s efficiency.

ULCOS hopes to build a small prototype at an ArcelorMittal plant in Eisenhüttenstadt, Germany next year, and to retrofit a commercial scale blast furnace with Top Gas Recycling at ArcelorMittal's Florange, France facility in 2015.

One catch: the consortium estimates that the Top Gas Recycling project will cost $665 million. It plans to apply for a European Commission carbon capture grant for about half that amount. The balance would come from ULCOS members and national governments.

In Europe, environmental groups like Greenpeace and Friends of the Earth have criticized steel’s efforts. They flat out oppose carbon capture on grounds that the carbon will eventually leak back to the atmosphere, and that it is costly and unproven. They also criticize the steel industry for lobbying against the EU’s plans to raise 2020 emissions reduction targets to 30% of1990 levels, up from 20%. And they call for an end to steel’s free carbon credits in Europe’s emissions trading scheme.

So, what about some of those altogether new, coke-free processes? Larry Kavanagh, president of the American Iron and Steel Institute's Steel Market Development Institute in Washington, D.C., says hydrogen and electrolysis could be ready commercially by sometime in the early to later part of the 2020’s. Kavanagh says AISI is developing a steelmaking process called Molten Oxide Electrolysis in partnership with MIT, and that it is working with the University of Utah on hydrogen-fuelled steelmaking.

But other industry executives say that the coke-free alternatives will not be ready until the middle of the century (that's a pile of coke to the right).

Until then, here’s something to ponder: who of us are not culpable in steel’s CO2 transgressions? Very few of us get by a single day without using steel. It’s everywhere – in roads, bridges, buildings, cars, you name it. It’s feeding global economic growth – China consumed almost half of all the planet’s steel in 2010, according to worldsteel.

Over the centuries, the steel industry has gotten very good at making quality product. Its coke formula isn't so beneficial for mother nature, but it makes a sound slab of steel. It underpins modern living and the economy. So, we keep going back for more.

What’s that you say? Your next car will be a carbon fiber model, and lightweight carbon fiber is ecologically sounder than steel? Well, consider this: according to the steel industry, no one has yet proven that carbon fiber is recyclable. I haven’t yet bounced that off the carbon fiber industry, but I feel another blog coming on.

IJmuiden Photo: Flickr

Coke Photo: Tradenote.net

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Mark Halper

Contributing Editor

Mark Halper has written for TIME, Fortune, Financial Times, the UK's Independent on Sunday, Forbes, New York Times, Wired, Variety and The Guardian. He is based in Bristol, U.K. Follow him on Twitter. Disclosure