Does the climate gas CO<sub>2</sub> also have a green side to it?
© Getty
December 2019

Does the climate gas CO2 also have a green side to it?

Whereas all previous plans revolved around storing the climate gas CO2 in underground layers of rock or just getting rid of it, it’s now supposed to be converted into a valuable raw material. Mattresses, carbon fibers and fuel: experts are working on the sensible utilization of CO2 to manufacture these and other products.

If Dr. Markus Steilemann has his way more and more people will soon be able to snooze on the climate killer CO2. The CEO of polymers supplier Covestro in Leverkusen is referring to the first products of the company’s “Dream Production” facility in Dormagen that was launched about three years ago. This is where Covestro – with the help of the notorious carbon dioxide – produces some 5,000 metric tons (5,500 short tons) of polyol per year – a substance that’s required for polyurethane foam in upholstered furniture and mattresses, etc. In a second stage, this chemical, which is normally produced completely from the carbon in petroleum, is planned to be used for the production of insulating materials for buildings or refrigerators and air conditioning systems.

CO2 to replace petroleum as a raw material

The subsidiary of chemical giant Bayer is one of the first companies in Germany to use carbon dioxide as a raw material for polymer production on an industrial scale – instead of dismissing it as undesirable waste. “With CO2 as a carbon supplier, we’re increasingly able to dispense with traditional fossil sources like petroleum,” says Covestro’s chemist Dr. Christoph Gürtler, who developed the facility’s processes in collaboration with the Catalytic Center of RWTH Aachen. Experts generally refer to this process as “carbon capture and utilization” (CCU). Thus, the climate gas is beginning to see a change in image: Previously, the main idea had been to pump the fraction of CO2 that cannot be avoided by switching to alternative propulsion or production technologies into underground storage areas. There, preferably captured forever in layers of rock, carbon dioxide was supposed to do no more harm.

Does the climate gas CO<sub>2</sub> also have a green side to it?
By means of CO2 Covestro produces the polymer polyol in this complex production facility© Feifei Cui-Paoluzzo/Getty
CO2 recycling is still in its infancy

Now the idea is to recycle the climate gas. This concept has begun to inspire widespread enthusiasm among the international scientific research community: All over the world, work on new efficient methods is in full swing. Not a month goes by without an announcement of new successes and products. U.S. scientists, for instance, produced carbon fibers from CO2 by means of electrolysis. In this way, it may even be possible in the future to produce this lightweight material at lower costs than by using conventional methods. Carbon Clean Solutions in the UK has presented a process that produces sodium carbonate, a pre-product of baking soda, using the carbon dioxide captured from the emissions of a coal-fired power-plant in a very economical way. The versatile sodium carbonate, colloquially known as soda, is also used in the production of paper, glass, adhesives, detergents and soap.

Success without subsidies

While the London-based company is not the first to produce soda from CO2 it’s the first one to have launched such a technology without government funding assistance. The company says that its product can be produced at costs which are two to three times lower than those of conventionally produced soda. A new chemical for filtering CO2 developed by Carbon Clean Solutions makes this competitive pricing possible. Compared with the currently used substance family of amines, it’s said to be more efficient, lower-cost and less corrosive, as well as requiring less energy to separate the captured carbon dioxide and being suitable for use even in smaller apparatus. A remarkable achievement considering that most CCU technologies are still thwarted by lack of economic feasibility.

Does the climate gas CO<sub>2</sub> also have a green side to it?
The specialists also use CO2 to produce binding agents for elastic floors in sports facilities© Feifei Cui-Paoluzzo/Getty
Only minimal climate protection?

To marry the chemically inert CO2 with other chemicals it needs a boost, which typically requires a substance facilitating the desired reaction – a so-called catalyst – plus plenty of energy that has to be supplied from an external source. Both combined cost time, lots of money and, in turn, frequently release carbon dioxide. Therefore, environmental organizations such as the WWF and Greenpeace criticize the development of CO2 recycling technologies as green-washing by the corporate world. However, industry is well aware of the fact that CCU will not save the planet overnight: “Of course the amounts of CO2 that can be used for the synthesis of such chemicals are very small compared to the annual CO2 emissions so that the effects on the climate will initially be small,” says Thomas Schaub, who is working on the production of the chemical formaldehyde from CO2 at BASF.

Facts and figures
  • 37,100 metric megatons
    (41,000 short megatons) of CO2 from fossil fuels were emitted by humans worldwide in 2017 – more than ever before. (Source: The Global Carbon Project)
  • 1,900 metric megatons
    (640,000 short megatons) of CO2 can still be emitted by us, after that the 1.5-degree global warming goal can no longer be met. Based on current emissions, this will cover a period of about 14 years (as of the beginning of 2018. Source: IPCC of the United Nations)
  • 580,000 metric megatons
    (640,000 short megatons) of CO2 can still be emitted by us, after that the 1.5-degree global warming goal can no longer be met. Based on current emissions, this will cover a period of about 14 years (as of the beginning of 2018. Source: IPCC of the United Nations)
Climate-neutral with renewable energy

Only if the energy for CCU processes were CO2-free as well, for instance by using wind power or photovoltaics, CCU would actually consume CO2. “But you’ve got to start somewhere,” says Schaub. The advantage of carbon dioxide, the scientist adds, is that’s available in very large amounts and at very low cost. However, it’s not clear yet whether Schaub will actually be able to produce formaldehyde, an important raw material for various plastics, from CO2 in the future. He and his team are currently looking for a catalyst that will make the reaction economically feasible. At least the results they’ve obtained so far look promising. In any event, such projects are important in paving the way for using CO2 as a raw material, says the chemist Schaub. “The technologies developed in the process can later be fed into significantly larger applications such as the production of liquid fuels.”

Does the climate gas CO<sub>2</sub> also have a green side to it?
A team headed by research scientist Dr. Christoph Gürtler has discovered the right catalyst for using CO2 in the production of polyol. Soft foam for mattresses is an initial application© privat
Component for climate protection

A number of other companies are planning or operating similar plants for fuels or fuel additives: RWE, Audi, LanzaTech, Carbon Engineering, Global Thermostat, Nordic Blue Crude and Ineratec, to name just a few. “However, there’s no technology that has come out on top yet in the production of such synthetic fuels,” says Georg Kobiela from the Wuppertal Institute for Climate, Environment and Energy. However, the expert in future energy and industrial systems cautions that, without additional supporting actions, relevant production quantities will not be achieved for a long time whether in the area of fuel production from CO2 or with most other CCU technologies in the chemical industry. “At this juncture, we’re talking about a decade and longer,” the scientist admits and therefore proposes instruments such as funding support, purchasing guarantees for the products, and opportunities for faster tax depreciation of the requisite equipment in order to accelerate the development of CCU technologies. “Because, clearly, we need it – as one component among many other actions that are required for climate protection.”

Perpetual motion through genetic engineering?

Meanwhile scientists like Daniel Nocera from Harvard University in the United States are working on the really big solution: artificial photosynthesis. His bionic leaf initially converts sunlight, carbon dioxide and water into hydrogen and oxygen. Genetically engineered bacteria subsequently absorb the hydrogen and together with carbon dioxide process it into biomass or other CO2-based base chemicals. In this way, an artificial carbon cycle might actually become a reality. If and when it does, the carbon dioxide emitted by automobiles, aircraft, ships and factories could just be captured by artificial leaves and transformed into fuel. However, we should not (yet) depend on this to happen.

Advantages of Iceland
Does the climate gas CO<sub>2</sub> also have a green side to it?© Getty

The Icelandic company Carbon Recycling International (CRI) has been using the advantages of the island in the North Atlantic for more than seven years: A geothermal power station delivers free waste heat and low-cost electricity as well as the climate gas in suitable concentrations. It rises there from the Earth’s crust. CRI produces 4,000 metric tons (4,400 short tons) of methanol per year in this way. The Icelandic company has now developed the process to a level at which it also runs with CO2 captured from the waste gases of chemical, steel and cement plants. Their next plant will be at least ten to twenty times larger and produce up to one hundred thousand metric tons (110,000 short tons) of methanol per year, according to Benedikt Stefánsson, Head of Business Development at CRI. In two years, the first large-scale production facility of this kind is planned to be launched in China.

More about the energetic volcanic island

Denis Dilba
Author Denis Dilba
Following his research for this article, technology journalist and engineer Denis Dilba, may opt for a CO2 model when purchasing his next mattress. He would also have a use for CO2-based synthetic diesel. The only question is whether his old VW van will hold up until the green fuel hits the filling stations.