Direct air capture

These 2 companies can pull CO2 straight from the air

The world might have been focusing on the coronavirus, but there’s another crisis that hasn’t gone away: climate change.

Key callouts

  • Climeworks and Carbon Engineering are two new World Economic Forum Technology Pioneers
  • Both are working on direct air capture, which removes carbon dioxide from the atmosphere
  • The captured CO2 can be stored or reused

Tackling it requires businesses, governments, civil society and individuals to take action – and there’s no silver bullet. We need to shift to net-zero emission by 2050, deploying technologies such as renewable power at scale so we stop pumping out carbon emissions.

One area that’s playing its part is technology. And two new World Economic Forum Technology Pioneers are helping show the way.

Welcome to the world of direct air capture

Climeworks and Carbon Engineering are both working on direct air capture – the process of capturing CO2 directly from the air.

It differs from other carbon capture methods, because it captures CO2 from the air around us, rather than at source – for example from industrial flues.

While not a solution to prevent global warming on its own, both companies argue it can play its role, alongside a net-zero industry transition, in both reducing and removing carbon dioxide emissions from the atmosphere.

So how does it work?

Both companies use fans to draw air in – you can see Climeworks’ units in the picture below.

From there, Climeworks captures carbon dioxide on the surface of a “highly selective filter material”. Once this material is full, the collector is closed and the temperature is increased to release high-purity, high-concentration CO2.

Carbon Engineering’s technology uses a potassium hydroxide solution to bind with the CO2 molecules drawn in by the fans. They’re trapped in this liquid solution as carbonate salt, before being put through a series of chemical processes – again to produce pure CO2 in gas form.

In both processes, the air is released back into the atmosphere with much lower – although typically not zero – carbon dioxide levels.

Right, so what can you do with the CO2?

The captured carbon dioxide can then be stored, or reused as a raw material.

Both companies use underground storage. For example, Climeworks has partnered with another company, Carbfix, to permanently store captured CO2 beneath the earth. The gas is mixed with water and pumped deep underground. Here it reacts with basalt rock and itself becomes stone “within a few years”.

If you don’t store it, potential uses include as building materials or for fuel and energy, according to a Columbia University blog. Carbon Engineering, for example, has a process to turn the CO2 into synthetic crude. This can then be turned into petrol, diesel and jet fuel for sectors where electrification remains a challenge – marine and air travel, for example.

The company says this process adds little or no new emissions to the atmosphere, compared to traditional fuels. The fuels release captured CO2 when they’re burned, simply returning levels to where they were. Or, if the CO2 is recaptured, you create a circular system of emissions.

What about the energy to run the systems?

Both systems need electricity and heat to run. Carbon Engineering uses a combination of renewable energy and natural gas, depending on conditions. If natural gas is being used, the CO2 generated is itself captured by the system.

Climeworks uses renewable energy, energy-from-waste or other waste heat. The company says for 100 tons of CO2 captured from the air, at least 90 tons are removed, with only up to 10 re-emitted.

Why capture carbon?

There’s debate about the benefits and value of carbon capture technology compared to emissions-reductions strategies, like investment in renewables. But its supporters argue it’s not an either or choice.

As Anthony Hobley, Executive Director of the Mission Possible Platform at the World Economic Forum, explains:

“It is imperative given the urgency of the climate emergency that we are facing that we develop and deploy all of the tools at our disposal to achieve net zero by 2050, including decarbonising our economies in line with robust net zero roadmaps and, where necessary, carbon capture technologies. Not as an alternative to net zero driven emission reductions but as well as – there is not enough time left for an either/or approach.”

In response to the COVID-19 pandemic, the World Economic Forum is calling for a “Great Reset” – a commitment to build the foundations of a fairer, more sustainable and more resilient future.

The initiative was launched by Professor Klaus Schwab and HRH The Prince of Wales, who explained: “In order to secure our future and to prosper, we need to evolve our economic model and put people and planet at the heart of global value creation. If there is one critical lesson to learn from this crisis, it is that we need to put nature at the heart of how we operate.”

Written by

Joe Myers, Writer, Formative Content

This article is republished from the World Economic Forum under a Creative Commons license. Read the original article.

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