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There is a general consensus among the scientific community regarding the dangers of global warming. The generally accepted statistic is that a 2°C rise in the average temperature of the planet compared with the pre-industrial era would lead to disasters on a large scale, including the submersion of some cities located at sea level and the destruction of natural ecosystems such as coral reefs. This is why world leaders meeting in Paris in 2015 agreed to limit the level of global warming to under 2°C. However, this target is already looking hard to attain. The planet is already 1°C warmer than in pre-industrial times, so room for manoeuvre is limited. In addition, although a lot of progress has been made in the field of renewable energy, we are still largely dependent on fossil fuels.

Around 80% of all energy produced worldwide comes from fossil fuels. This percentage has remained stable since the mid-1980s, but global expenditure on energy has doubled since then, meaning that we are burning twice as much coal, oil and natural gas as before. In 2017, CO2 emissions, which play a major role in global warming, rose by 2%, having remained stable for three years before that. Now that the United States has pulled out of the Paris Agreement on climate action the 2°C target looks likely to remain mere wishful thinking.

Much is talked about ways and means of reducing CO2 emissions, for example through the use of green energy technologies, but far less is said about methods of eliminating CO2 that has already been emitted. ‘Prevention is better than cure’ the old adage tells us, and it is indeed preferable not to emit CO2 in the first place rather than trying to get rid of it once the deed has been done. However, now that the timeframe is becoming tighter, a number of players are launching initiatives in this field. One example is the Canadian company Carbon Engineering, New York-based Global Thermostat and Climeworks, whose headquarters are in Zurich.





Turning CO2 into rock



Swiss firm Climeworks makes eight-cubic-meter units, which look as if they have come straight out of a 1980s science-fiction film. Each unit houses a number of CO2 collectors. Climeworks co-founder and Managing Director Christoph Gebald, with whom L’Atelier met up during the Web Summit held in Lisbon in November, briefly explains the process as follows: “Each collector contains a huge fan, which pulls ambient air inside. Then a filter captures the CO2 and binds it to the filter surface, while the purified air is released outside. Lastly, the inside of the collector is heated to 100° to clean the filter of CO2, which is collected in concentrated gaseous form.” A filter can be re-used thousands of times and each box can collect 50 tons of CO2 a year, i.e. the equivalent of the emissions from 30 cars. So far the company has installed its technology at one plant in Switzerland and one in Iceland.

Of course, Climeworks’ Direct Air Capture (DAC) process needs power to drive it. In order to avoid burning fossil fuels – which would mean generating CO2 in order to capture CO2 – the company uses renewable sources of energy. In Iceland, energy generated by local geysers is used to heat the collectors so as to extract the CO2 from the filters. Going forward, Christoph Gebald is also planning to use solar energy for installations at venues with warm climates, such as Morocco and the south of France.

CLIMEWORKS’ DAC technology turns CO2 INTO ROCK


Climeworks generates its revenue by charging client companies looking to reduce their carbon footprint a periodic fee so as to enable Climeworks to install and run additional collectors. The system enables Climeworks clients to help pay for reductions in atmospheric CO2 and at the same time reduce their own carbon footprint, thus obtaining a tax advantage. In some industries, such as aviation, there is currently no alternative to fossil fuels. Absorbing carbon dioxide from the atmosphere is therefore the only way companies in these sectors can make their operations carbon-neutral.

That all sounds fine, but what can be done with the CO2 captured during the process? Christoph Gebald is not short of ideas here. In Iceland, which rests on a very special basalt sub-structure, CO2 stored underground very quickly turns into mineral deposits. At the Hellisheidi power plant, Climeworks injects CO2 captured from air and mixed with water into the underground strata, where it quickly turns to rock. In the United States, the Illinois State Geological Survey has for several years been testing a similar method. Another option is to monetise the CO2 collected by selling it to companies in the metals and plastics industries or the agri-food business, which use carbon dioxide in their production processes. 



From yoga pants to aircraft fuel

We want people to have a choice of where their carbon comes from. Fresh fossil or recycled, ‘carbon smart’, products.

Jennifer Holmgren

Last but not least is the option of recycling CO2. This is where LanzaTech comes in. This Chicago-based startup has developed an ingenious process for transforming CO2 using fermentation techniques. Explains Freya Burton, Chief Sustainability and People Officer at LanzaTech, whom L’Atelier also met at the Web Summit: “It’s as if you were brewing beer but the sugar and yeast are replaced by bacteria and CO2. We use a huge tank; the bacteria live in the liquid. When they come into contact with the gas they feed on it and transform it. This fermentation process can produce fuel or a range of chemical substances, depending on what you want to use them for.”   

The LanzaTech Process
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LanzaTech has obtained grants from both the European Commission and the US Department of Energy. Among other clients, the company is working with the steel-making industry which is, says Freya Burton, the third largest CO2-emitting industry. LanzaTech is currently working to instal its system at two steel plants: an ArcelorMittal plant in Belgium and a plant in China. In both cases, the CO2 will be recycled to produce ethanol, which can be used as a fuel for vehicles, and perhaps also for aircraft in the near future. Apart from fuel, a second option is to create raw materials. Chemical substances can be synthesised by the bacteria, which means that natural and synthetic fibres can be produced for such purposes as manufacturing clothes.

“Imagine wearing yoga pants made from recycled carbon!” says LanzaTech CEO Jennifer Holmgren. She explains: “We want people to have a choice of where their carbon comes from. Fresh fossil or recycled, ‘carbon smart’, products. Much like the idea of buying organic, fair trade or recycled products, we see a future where you can walk into a store and make a conscious decision to buy everything from a chair to running shoes made from recycled carbon. This future is now possible through advancements in synthetic biology which enable the production of targeted molecules.” From yoga pants to aircraft fuel –  clearly there is a wide range of possibilities! 


industrie energie


A major question

For companies that generate CO2, using this technique translates directly into hard cash. “Today all steel-producing companies still burn the CO2 they use. This costs them money in carbon taxes. On the other hand our solution enables them to make money out of their CO2 by transforming it into something useful,” underlines Freya Burton.

This approach therefore goes nicely hand in hand with the Climeworks solution. The two technologies could work in synergy together, with LanzaTech recycling the CO2 captured from the atmosphere by the Climeworks equipment. No surprise then that the two companies are currently in talks with each other.



However, these systems will have to be able to function on a large scale if they are to provide a real solution to global warming. For the moment Climeworks’ capacity remains modest, but Christoph Gebald is thinking big. He reveals: “We’ve captured a thousand tons of CO2 from the atmosphere this year. Of course, that’s just a drop in the ocean. We need to start talking gigatons, but our technology can be deployed on a massive scale. Our systems are small-scale, they’re about the size of a car and weigh about the same – 2,000 kilogrammes – so they can easily be mass produced using scaled-up industry infrastructure, which would also reduce costs. At the moment our main challenge is to harness existing production infrastructure to serve our technology.”

Freya Burton believes that LanzaTech’s technology can also be used easily with existing infrastructure. “We’ve always worked on the basis that we must be able to roll out the technology at scale. On the one hand, the fuel our process produces is one of the cheapest on the market, and so offers real economies. On the other hand, our technology can be incorporated into any steel-making factory in the world, plus also into refineries, waste recycling plants, etc. So there’s a lot of existing infrastructure on to which our technology can be grafted.”

Despite all these opportunities, change is not going to happen overnight, and political action will be needed in order to make any headway. Freya Burton sums up the situation: “People always think that implementing the technology will be the hardest part, whereas in actual fact it’s really about the legal situation. When you put forward really innovative technology, you have to educate people and get them to think differently. I think that if environmental policy is going to be effective it should be technology-neutral. Today, for instance, legislation on renewable fuels only supports plant-based fuels. If you want to keep global warming under 2°C, you need to involve every possible player. In my opinion, more neutral policies, such as California’s low-carbon fuel standard (LCFS) regulations for transportation fuels, are more likely to foster the emergence of new technologies.”

By Guillaume Renouard