How negative emissions technology can create a sustainable future

A month ago, the world's biggest C02 capture plant came online in Iceland. The innovative Direct Air Capture plant is the next generation tech that could help the planet eliminate the legacy of fossil fuel use.

Built by Swiss company Climeworks, the plant uses renewable geothermal power and locks C02 emissions away in basalt rock, rather than controversial pipelines. Climeworks other plants recycle C02 for use in fertilisers and fizzy drinks. A similar plant in Switzerland currently sucks 900 tonnes of emissions from the air. However, to put that into context, we currently emit 40 billion tonnes of C02 every year.

Named Orca, from the Icelandic for energy, the air capture plant will draw down 4,000 tonnes of emissions annually. Larger plants are already in the pipeline, but Orca has a surprisingly small footprint and uses an array of fans to suck in air and separate out harmful emissions which are then sequestered in rock.

Race to reduce

Vacuuming carbon directly from the atmosphere is attracting major investors for companies like Climeworks. Governments are interested in the capabilities of direct carbon capture, as are corporations including Microsoft. Climeworks policy chief Chris Beuttler calls the existing plants 'a drop in the bucket' and accepts that the technology needs to scale fast. Beuttler says all carbon capture technologies need to be capable of extracting several gigatons to have a real impact.

Other firms, like Canada's Carbon Engineering and the US based Silicon Kingdon Holdings are working on mechanical trees that allow carbon to be sequestered or reused. Although carbon capture has been around for a while, costs have made it too expensive. As the scale of the task to reach Net Zero emerges, however, costs are falling and investment is pouring in. Ironically, oil producers are investing heavily in carbon capture as C02 can be used in the extraction of fossil fuels in a process called enhanced oil recovery.

Climeworks are also selling carbon credits to big names like Microsoft who are racing to reduce their emissions by 2030. The tech giant is both an investor and a customer of Climeworks.

Modular milestone

Orca has been constructed using a modular system of stackable containers, making it relatively easy to scale the design. Orca uses eight units with a carbon cleaning capacity of 500 tonnes each. This system allowed Orca to be built in a little under 15 months.

Each unit holds several giant fans that draw air into a collector where it passes over a carbon capture filter. Once the filter is filled, the container is closed and the temperature increased to release the carbon from the filter. It's then mixed with water - around 27 tons of water for every ton of carbon - and pumped deep underground. The carbon dioxide then reacts with the basalt rock and creates carbonate rock. What was once sparkling water will turn to stone within two years.

Climeworks co-CEO and co-founder Jan Wurzbacher said the facility was a milestone in carbon capture technology, providing a scalable, replicable and flexible blueprint for future Climeworks projects. The company is preparing to ramp up production and is aiming for gigaton capture by mid-decade.

Achieving the Net Zero goal still requires a huge amount of work and investment, but the success of Orca may bring that future another step closer.