Risk. No unapproved passage. Hot overflowing with progress.” If anything,

The sign underneath the grimy hunk of mechanical apparatus underplays things. At the point when the 11-ton section of metal I’ve been viewing rises up out of the heater, warmed to 1300°C, it shines brilliant white. At that point, it speeds along a transport line, murmuring and steaming as it is cooled by water streams before a line of folding chambers presses it into the last item: a sheet of shining steel.

For all that we live in the computerized age, regardless, we depend on hot and messy procedures like this to build our urban areas, homes, and vehicles. Strolling around the steelworks in Newport, UK, I get a feeling of the huge vitality required – and this is just the phase at which the steel is worked. Making it from crude iron mineral is considerably increasingly escalated. Indeed, the creation of steel and that other development staple, solid, represents as much as 16 percent of mankind’s yearly carbon dioxide outflows. That is proportionate to the carbon impression of the US.

In the battle against environmental change, overwhelming enterprises are the last boondocks. Decarbonizing transport and vitality is the normal part. Steel and cement are various monsters. It is a lot harder to create them without discharging tremendous measures of CO2 into the air. But then in the event that we need to arrive at net-zero carbon targets, we can never again overlook them. Tidying up cement and steel is such a gigantic test, that it can appear to be miserable. Be that as it may, scientists and groundbreaking organizations are spearheading savvy approaches to split the issue – maybe directing the route toward a significant atmosphere win.

The need to act couldn’t be progressively evident. On the off chance that we don’t keep worldwide temperature ascends beneath 1.5°C, dry seasons, floods, and outrageous warmth are anticipated to be a lot of more terrible. Normal fortunes, for example, corals, also all way of other living things, possibly obliterated.
In the parts of our economies that emit the most CO2, such as transport and energy, we have most of the technology we need to make that happen. Electricity generation can flip to low carbon sources such as wind and solar, cars can switch from combustion engines to battery power, and buildings can be insulated so that they use less energy. We just need to generate the will to implement these changes. Solutions are nowhere near as evident for heavy industry. The world produced more than 1.8 billion tonnes of steel last year, for example. Concrete production is even higher, and demand for both is likely to grow for decades. Both industries seem to fly under the radar in the climate conversation, but make no mistake, they produce whopping amounts of carbon. “They are responsible for half of all industrial emissions,” says Julian Allwood at the University of Cambridge, who was lead author on the problem of industry’s carbon footprint for the most recent report by the Panel on Climate Change. Although efficiency drives have reduced the footprint from steel and concrete to a degree, they still have a long way to clean up their act.
Reuse and recycle The problem for both materials is that their production processes seem almost unavoidably carbon-intensive, and tried and tested, scalable alternative methods have been conspicuous by their absence.
Most steel is made using a combination of a blast furnace to extract iron from its ore and a basic oxygen furnace to convert this raw iron to steel. In essence, iron ore is heated by burning carbon-rich coking coal, creating CO2 as a by-product. Hence, “the major thing would be to shift away from blast furnace operations,” says Paul Fennell of Imperial College London.
One alternative is to recycle more. It is a simple enough process: put scrap steel into an electric arc furnace, where electrodes produce a current that melts the steel so it can be reworked. This can reduce carbon emissions by about two-thirds for each tonne of steel produced compared with that made from iron ore. The electricity can, in principle, come from renewable resources.
That sounds like a win-win. Liberty Steel, the owner of the steel rolling mill I visited in Newport, certainly seems to think so, because it has plans to recycle a lot more steel. The mill isn’t far from Uskmouth B power station, a 1950s coal-fired power plant that has been dormant since 2017. Now, Liberty’s parent company GFG Alliance is spending £200 million on converting the power plant to a lower- carbon fuel: pellets made from non-recyclable plastic and other waste. It will send much of its electricity straight to the steelworks, where the firm hopes to build an electric arc furnace.
The wrinkle at this stage is that some sectors, such as car manufacturers, still prefer to use virgin steel. One concern is that impurities like copper can build up and make recycled “Many observers think steel more mediocre quality, reducing its potential uses. “At the moment, we can make construction concrete production is grade steel from recycling, but not automotive steel, meaning it would require governments to introduce some form of the carbon levy on steel product into make it economically competitive. “Until you think there is going to be a significant and sustained carbon price, the commercial driver is just to produce iron and steel in the way you already produce it,” says Fennell.
Concrete suffers from many of the same problems, starting with the basic chemistry involved in its production: CO2 emissions are inherent in making its component parts. Take cement, the “glue” that holds the concrete together. To make it, you first grind and heat limestone in rotating kilns. The ensuing process of calcination decomposes the limestone’s calcium carbonate into calcium oxide, releasing CO2. The next stage requires yet more energy to heat calcium oxide with other materials to make a substance called clinker. Add this to the soft mineral gypsum, and you get cement.
Many observers think the sector is almost impossible to clean up. Allwood puts it bluntly: “There are no options to decarbonize cement.” But that hasn’t stopped people from trying.
One option is to use a different kind of cement. Almost all concrete is made using Portland cement, a 19th-century formula that works well. But there are plausible alternatives.
Grade,” says Allwood. Yet he adds that such impurities can be minimized by better sorting of materials before recycling them and by removing dirt from the molten steel.
The other option is to make raw steel using a greener process – and to that end, there is a push in some quarters to convert iron ore, not with coking coal but hydrogen. The idea is that the oxygen in the iron ore will combine with the hydrogen to produce water instead of CO2. SSAB, a steel-making company headquartered in Stockholm, Sweden,
is among those exploring this strategy,
which it has called HYBRIT.
There is a caveat. For the moment, hydrogen is overwhelmingly made from fossil fuels, such as natural gas, and that means greenhouse gas emissions: the carbon footprint of global hydrogen production is on a par with the emissions of the UK and Indonesia combined. But it is possible to make hydrogen from water using an electrolyzer powered by electricity from renewable sources. If we one day have enough excess wind power, we could potentially produce all the hydrogen we need for large-scale clean steel production via electrolysis – that is, if the economics somehow worked out.
Promising. But part of the problem when it comes to decarbonizing steel is the state of the industry. Unlike oil and gas, which continue to yield extravagant profits for producers, steel makers outside China are struggling to stay afloat. As a result, they don’t have much leeway to cover the costs of new low-carbon technology. Nor have they enjoyed the support of governments in the same way as the renewable electricity sector, which has benefited from subsidies for over a decade.
SSAB says its hydrogen-produced steel could be 30 percent more expensive than standard steel, meaning it would require governments to introduce some form of the carbon levy on steel production to make it economically competitive. “Until you think there is going to be a significant and sustained carbon price, the commercial driver is just to produce iron and steel in the way you already produce it,” says Fennell.
Concrete suffers from many of the same problems, starting with the basic chemistry involved in its production: CO2 emissions are inherent in making its component parts. Take cement, the “glue” that holds the concrete together. To make it, you first grind and heat limestone in rotating kilns. The ensuing process of calcination decomposes the limestone’s calcium carbonate into calcium oxide, releasing CO2. The next stage requires yet more energy to heat calcium oxide with other materials to make a substance called clinker. Add this to the soft mineral gypsum, and you get cement.
Many observers think the sector is almost impossible to clean up. Allwood puts it bluntly: “There are no options to decarbonize cement.” But that hasn’t stopped people from trying.
Almost all concrete is made using Portland cement, a 19th-century formula that works well. But there are plausible alternatives. Some carbon savings are already made by using existing cement substitutes. One is fly ash, a fine powder produced as a by-product by coal power stations. Another is a by-product of iron-making called ground granulated blast-furnace slag. But we are trying to phase out coal plants for good reasons, and there is only so much of this slag.
Elsewhere, researchers have started looking at using a calcium silicate slag that is a by-product of the steel industry as a substitute for cement. It is typically dumped in landfills. Carbicrete of Canada is one firm eyeing this route and promises significant carbon savings, but it is unclear, commercially speaking if it has made any inroads.
All of these new formulations share two main problems. The first is a familiar one: they are more expensive than the current recipes. The second is a consequence of the first. No one is making them in volumes that would start to bring costs down. “There is alternative cement being developed in labs, but none at a meaningful scale,” says Allwood.
A small hope can be found in Lixhe, Belgium, where researchers are experimenting with a different approach. Here, a plant owned by German company Heidelberg Cement has been retrofitted with a 13-story tower designed to capture the carbon produced during cement-making before it gets into the atmosphere. The aim of the Low Emissions Intensity Lime And Cement (LILAC) project, partly funded by the European Commission, is to test new technology – one that separates the CO2 released from other waste gases, to capture a pure stream of CO2.
Capture and convert Fennell, who is involved in the project, believes it has promise in part because the CO2 could be a commodity to sell to other industries, such as plastic manufacturing. “It’s one of these rare processes that might have a minimal downside,” he says.
Scaling up could have an eye-watering price tag, though: LEILAC is a €21 million scheme but will handle just 2 percent of production at Lixhe, a typical-size cement plant. That hasn’t stopped Heidelberg Cement pushing ahead with a report, based on a similar trial at a Norwegian cement plant, that will have a big say on whether it sinks funds into a full-scale project in Norway. In principle, carbon capture and storage technology could help mitigate the carbon footprint of both concrete and steel. It is often mooted as a potential solution in the energy sector, and Luke Warren of the UK Carbon Capture and Storage Association says attention is beginning to turn to its use in heavy industry.
However, the truth is that the technology is still in its infancy. Despite its undoubted promise and years of efforts to make good on it, there are only 23 large-scale facilities in the world, capturing 40 million tonnes of CO2 a year, chiefly in natural gas processing plants where it is easier to implement. That amounts to just 0.1 percent of humanity’s emissions.
Ultimately, the quickest climate win for both concrete and steel may end up being the simplest: use less of it, and make what we do use last longer. In the book Sustainable Materials: With both eyes open, Allwood and his colleagues sketch out how we could cut the emissions from these two materials by 50 percent by 2050 by designing buildings to use less of them. A case in point is the velodrome built for the 2012 Olympic Games in London, for which the choice of a lightweight roof made of steel cables meant using 27 percent less steel than a conventional arch-based design would have required. Similar approaches are being explored for concrete. “Our mantra has used enough material and no more,” says architectural researcher Paul Shepherd at the University of Bath, UK. In January, he started construction of an office building using concrete beams that can bear the loads needed but are shaped to require less material than usual. And in some cases, we could just use wood instead.
Back at the steelworks in Newport, management is understandably hoping to ramp up the amount of metal they turn out.
If things go to plan, the output could double next year. And yet globally, the most credible and readily available route to a low-carbon future lies in the opposite direction. That is undoubtedly how Kirsten Henson at KLH Sustainability, a construction consultancy that advised the London Olympics, thinks about steel and concrete: “We’ve got to use less of it,” she says.

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