Climate change: the "magic" carbon solution takes a big step

A technology that removes carbon dioxide from the air has enjoyed significant support from large fossil fuel companies.

Carbon Engineering, based in British Columbia, has demonstrated that it can extract CO2 in a cost-effective way.

New investments of $ 68 million from Chevron, Occidental and BHP coal giant were generated.

But climate activists worry that the technology will be used to extract more oil.

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The search for technologies for the removal of carbon dioxide (CDR) in the air has received considerable scientific support last year with the publication of the IPCC report on the maintenance of rising temperatures. worldwide at 1.5 ° C this century.

In their "summary for decision makers", the scientists said: "All pathways that limit global warming to 1.5 ° C with limited or no overshoot provide for the use of CDR. in the 21st century ".

Around the world, a number of companies are striving to develop a technology that can reduce carbon emissions. The Swiss company Climeworks already captures CO2 and uses it to stimulate vegetable production.

Carbon Engineering says its Direct Air Capture (DAC) process is now able to capture gas for less than $ 100 a tonne.

With its new financing, the company plans to build its first commercial facilities. These DAC factories on an industrial scale could capture up to one million tonnes of CO2 in the air each year.

So, how does this system work?

CO2 is a powerful warming gas, but the atmosphere contains very little. For every million air particles, there are 410 CO2.

While CO2 helps to raise temperatures worldwide, relatively low concentrations make it difficult to design efficient machines to eliminate gas.

The Carbon Engineering process involves drawing in air and exposing it to a chemical solution that concentrates CO2. Additional refinements mean that the gas can be purified in a form that can be stored or used as a liquid fuel.

Does this require complicated chemistry?

Absolutely.

The installation of the size of the Barn Engineering Carbon is equipped with a large fan in the middle of the roof that sucks air from the atmosphere.

It then comes into contact with a chemical solution based on hydroxide. Some hydroxides react with carbon dioxide by reversibly binding to the CO2 molecule. When the CO2 in the air reacts with the liquid, it forms a mixture of carbonates. This is then treated with a sludge of calcium hydroxide to change it into a solid form; Slurry helps form tiny calcium carbonate pellets.

The chalky calcium carbonate pellets are then treated at an elevated temperature of about 900 ° C, the pellets decomposing into a stream of CO2 and calcium oxide.

This pure CO2 stream is cleaned to remove impurities from the water.

"The key to this process is concentrating CO2," said Dr. Jenny McCahill of Carbon Engineering.

"We can then put it underground as in a sequestration, or we can combine it with hydrogen to form hydrocarbons or methanol.You can do a number of things."

Can you really make a liquid fuel from CO2?

Yes. It's complicated but it can be done.

The captured CO2 is mixed with hydrogen based water and green electricity. It is then passed over a catalyst at 900 ° C to form carbon monoxide. Adding more carbon monoxide makes it a gas called synthesis gas.

Finally, a Fischer-Tropsch process converts this gas into synthetic crude oil. Carbon Engineering indicates that the liquid can be used in a variety of engines without modification.

"The fuel we produce does not contain sulfur, it contains these beautiful linear chains, which means it burns more cleanly than traditional fuel," said Dr. McCahill.

"He is handsome and clear and ready to be used in a truck, a car or a jet."

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Why are fossil fuel companies investing in this process?

CO2 can also be used to remove the last remaining oil deposits in wells that have passed their peak. The American oil industry has been using gas in this way for decades.

It is estimated that the use of CO2 can provide 30% additional crude from oil fields, with the added benefit of sequestering the gas permanently in the soil.

"Carbon Engineering's direct-to-air capture technology has the unique ability to capture and deliver large volumes of atmospheric CO2," said Richard Jackson, vice president of Occidental Petroleum, in a statement. communicated.

"This capability complements Western's enhanced oil recovery activities and creates new synergies by enabling large-scale CO2 use and sequestration."

One of the other investors in Carbon Engineering is BHP, best known for its interests in coal mines.

"The reality is that fossil fuels will be present for decades, whether in industrial processes or in transportation," said Dr. Fiona Wild, Sustainability and Climate Change Manager at BHP.

"What we need to do is invest in low-emission technologies that significantly reduce the emissions from these processes, which is why we focus on carbon capture and storage."

How did environmentalists react to Carbon Engineering projects?

Some climate activists favor the development of direct-air capture technology, but others fear it will be used to extend the fossil fuel era.

"This is a major concern," said BBC News Tzeporah Berman, director of the international program for Stand dot Earth.

"We need to work together to find a way to get away from fossil fuels altogether, it's our moral and economic challenge, but these technologies offer a false hope that we can continue to depend on fossil fuels and produce and burn them, correct -the – we have exceeded this point! "

Others are concerned that the development of direct air-catching devices may simply lead some people to believe that they are not required to personally reduce their carbon footprints.

"I think there's a real danger that people will see this technology as a quick fix and not reduce their carbon emissions," said University of British Columbia student Shakti Ramkumar. (UBC), which actively participates in climate change protests.

"We have a moral responsibility to reduce our consumption on a large scale, we need to think deeply about how we live our lives and that everyone can have access to what we have and to equity, so that we can all live a good life. "

Is this technology a "miracle solution" for climate change?

It is impossible to say if the idea of ​​Carbon Engineering will become the type of device that will make the difference in the fight against climate change.

Certainly, the company thinks that its machines could become as common as the water treatment plants – offering a valuable service, but barely noticed by the general public.

At present, he has got enough money to build a commercial facility and can draw carbon for less than $ 100 a ton. But there is considerable concern that, with the significant investments of the fossil fuel industry, its focus will be on oil production, not just climate change.

Carbon Engineering says that if governments want to invest in this process, they are welcome. If they are not ready to spend money, the company is happy to receive funds from the energy sector as time is running out, and so much technology is needed.

"Is this the money ball?" asked the CEO Steve Oldham.

"I would never tell anyone that you want to put all your eggs in one basket – the future of the planet is very important to us all.

"But having the technology built, available, ready for use, without harmful chemical side effects, without land use, without these resources available – that's a good thing.

"If or when we need it, and if you read the science of today – it's available, it's ready."

Follow Matt on Twitter @mattmcgrathbbc.