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Today, Tongyezhen hosts a sprawling industrial park where huge ovens bake coal and limestone into coke and lime, both key ingredients for producing steel.
Carbon Recycling International , the Reykjavik-based firm behind the operation, says that the Tongyezhen plant will recycle about 160,000 tonnes of CO2 per year — equivalent to the emissions from tens of thousands of cars — that would otherwise go into the atmosphere.
But why not recycle it into products that are both virtuous and profitable? As long as the recycling process avoids creating more carbon emissions — by using renewable energy, or excess resources that would otherwise be wasted — it can reduce the CO2 that industry pumps into the atmosphere and lower the demand for fossil fuels used in manufacturing.
The market for these products is tiny today, amounting to less than US$1 billion — but Lux predicts that it will grow to $70 billion by 2030, and could reach $550 billion by 2040.
This activity is being driven by a fall in the cost of renewable energy, along with rising carbon taxes and other climate incentives that are persuading firms to avoid CO2 emissions.
Many of the products made this way only briefly delay carbon’s journey into the atmosphere — fuels are burnt, products made from chemicals degrade and the CO2 consumed during their creation is released again.
Meanwhile, some estimates suggest that the global market for recycled CO2 products is unlikely to lock up more than a few per cent of the CO2 that humans release into the atmosphere by burning fossil fuels, which totalled 36 billion tonnes last year.
“The assumption that we can fix this climate-change problem in an economically attractive and easy way — at best it’s naive, and at worst it’s actively disingenuous,” he says.
Roughly 200 million tonnes of CO2 are used in a handful of processes each year, most of it reacted with ammonia to make urea for fertilizers.
That is why so many early plants are located where there are plentiful streams of high-purity waste CO2, widely available spare hydrogen and heat , or low-cost renewable electricity.
CRI, for instance, opened its first CO2-to-methanol plant in 2012, next door to a geothermal power station in Iceland.
“But companies that need to source renewable fuels are willing to pay a premium for it.” And the firm has customers: as well as the facility in Tongyezhen, CRI is working on other full-size plants in China’s Jiangsu province and in northern Norway.
California-based start-up firm Twelve, for instance, aims by the end of this year to have an electrolyser system the size of a shipping container that uses electricity to process more than one tonne of CO2 each day into syngas.
Adding a metal catalyst to one of the device’s electrodes enables it to simultaneously convert CO2 into CO, so that the system produces syngas at room temperature.
Nevertheless, many catalysts struggle to work for more than a few hundred hours before they start to degrade, says Jan Vaes, programme manager for sustainable chemistry at the Flemish Institute for Technological Research near Antwerp, Belgium.
Avantium, a renewables chemical company in Amsterdam, is using improved catalysts2 to make formic acid, which can be converted into more-valuable chemicals.
This year, for instance, electrical engineer and materials scientist Edward Sargent at the University of Toronto in Canada and his team unveiled an electrochemical system that converts CO2 and water into ethylene oxide, which is widely used to make polymers.
Whether products recycled from industrial CO2 emissions actually protect the climate is unclear — because the CO2 they capture will still be released into the atmosphere if the molecules are burnt or broken down.
Proponents argue that recycling industrial CO2 into chemicals can reduce emissions in another way — by avoiding some fossil-fuel-based production.
The stringent way to examine this is through a life-cycle analysis — a detailed accounting of the carbon involved in making and using a product, from the origins of its CO2 to its final fate.
A second plant began operating at a Chinese alloy plant last year, and commercial plants in Belgium and India are expected to come online by the end of this year.
On 8 March, LanzaTech announced that it would become publicly listed, a move that values the company at $1.8 billion.
But she concedes that it is hard to be certain this is true — CO2-based products might simply add to the growing global consumption of fuels and other chemicals, rather than displace incumbent production.
Anyone who is trying to limit their international flights, for instance, might fly more often if their airline boasts of its climate-friendly fuel.
“You’re making products like insulation foam, mattresses, soft furnishings, that have quite a long lifetime,” says Charlotte Williams, a chemist at the University of Oxford, UK.
Williams develops catalysts that can incorporate CO2 into polyols, which are used to make polyurethane foams. Polyols are usually made from expensive chemicals called epoxides, but her catalysts help CO2 to take the place of some of these in the polymer chain.
In September 2021, it signed a deal to build a pilot plant in India, and then retrofit an existing plant to incorporate waste CO2 into polyols.
Despite this progress, projections suggest that using CO2 as a polymer ingredient would lock up only around 10 million to 50 million tonnes of CO2 per year by 20506.
The biggest opportunity to incorporate CO2 into products lies in concrete and other building materials, says Runeel Daliah, a senior analyst at Lux Research, who is based in Amsterdam.
Because cement-making accounts for most of concrete’s carbon emissions, the company says this could reduce the carbon footprint of every tonne of concrete by around 5% .
The company has installed more than 550 of its CO2 injection units at concrete plants around the world, most of them in North America, which has avoided and mineralized 150,000 tonnes of CO2 emissions so far.
When it comes to making fuels and other chemicals, most CO2-derived products are currently more expensive than their conventional rivals, says Josh Schaidle, who led an analysis by the US National Renewable Energy Laboratory in Golden, Colorado, of 11 products made by CO2 conversion8.
In the European Union, for instance, a broad package of policy incentives under the banner of the European Green Deal aims to make the bloc climate neutral by 2050.
But in 2021, key players in China’s gigantic chemicals industry pledged to invest in CO2-based chemical production, a move that could win financial support through the country’s carbon-trading market, which launched last year.
The success of the CO2-conversion businesses, however, could rest on LCAs and other measurements of carbon flows.
In a report10 published in February, environmental scientist Kiane de Kleijne at Radboud University in Nijmegen, the Netherlands, and her colleagues scoured dozens of published LCAs to compare CO2 conversion routes with conventional ways of making the same products.
Climate-focused academics conducting LCAs often note that geological storage of CO2 is better than conversion because it offers much greater reductions in emissions.
But there is at least one point of broad agreement: that CO2 recycling technologies should eventually draw as much of their feedstock as possible from the atmosphere, rather than from waste industrial gases.
It costs $600–800 to sequester one tonne of CO2 in this way — hardly cheap — but the company says it can slash that to one-tenth of the cost as it scales up.
Even if there are limited climate benefits from converting today’s fossil CO2 emissions into products, some companies argue that it’s important to develop the technology so that it is ready to feed off CO2 from the air once direct air-capture technology matures.