Science & Tech

Breakthrough in Capturing Carbon Dioxide Emissions and Converting to Fuel

A British Columbia company claims it has done the impossible. It has found a way to efficiently remove carbon dioxide out of the air and convert it into fuel for an estimated one-third of what any other company has accomplished to date.

Carbon Engineering has developed a process that involves what it refers to as “Direct Air Capture”. The core idea behind it dates back to the 1950s when CO2 was separated from ambient air for use in cryogenic air separation. In the 1990s a scientist named Klaus Lackner began investigating carbon dioxide capture as a means of mitigating climate change issues.

The method involves the use of an aqueous basic solution ‘sorbent’ (absorber) made of KOH (potassium- oxygen-hydrogen). The carbon dioxide is extracted and transferred to a calcium recovery loop, which, with other processes, eventually releases the gas at the end. The gas is then combined with Hydrogen and Oxygen to convert it into a usable fuel.

As noted in the company’s recent paper on the topic, “A Process for Capturing CO2 from the Atmosphere”, with this approach the “cost per ton CO2 captured from the atmosphere ranges from $94 to $232 dollars”.

The most important immediate benefit of this is of course that it could provide a cost-competitive solution to what some in the climate change field see as mandatory. With greenhouse gas emissions continuing to rise well beyond the limits called for in the Paris Climate accords, the only way to make any major dent in accelerating global warming may be to pull excess carbon dioxide out of the atmosphere.

Carbon Engineering is not the only company chasing this dream. Climeworks, a Swiss-based enterprise, has already built a commercial-scale plant using a related process. The cost of Climeworks’ approach is much higher, however, based on choices of specific technologies and processes it uses. It costs them approximately US $600 per ton to pull carbon dioxide out of the atmosphere. This compares to an estimated worst case of about US $232 per ton to an estimated best case of US $94 per ton.

At least six other companies around the world are also known to be pursuing the same basic idea as Carbon Engineering but are at far earlier stages in their development process.

As the paper notes, besides the cost difference, Carbon Engineering says it is the first to disclose in verifiable detail how the entire process can be built. It has a second advantage that its approach uses easily-acquired components and existing technology throughout. The innovation comes in creating the entire system that produces the final product.

With the current design approach, Carbon Engineering’s carbon extraction and fuel production process requires some natural gas to be used. That does mean its final fuel is not totally carbon-free, with estimated total emissions of a half-ton of carbon dioxide for every full ton of carbon dioxide removed from the air. According to the scientists at Carbon Engineering, this means the resulting fuel’s final carbon footprint is about 70% of what a conventional fossil fuel would produce.

At Carbon Engineering’s Squamish, B.C. plant, the pilot structure they have set up currently extracts approximately a ton of carbon a day out of the sky. Steve Oldham of Carbon Engineering says the system should be able to scale up. That is mostly because all the key components are already in production and easily sourced.

Next for Carbon Engineering is to do just that – scale up. With a recent capital injection of $11 million It plans to build a full-scale plant, and to have it up and running at full capacity in about 2.5 years.

The company has been offered an AMERO grant.