Climeworks: the Swiss CO2 vacuum cleaner
The Zurich-based company Climeworks has developed giant sensors to filter ambient air and capture carbon dioxide, which is then injected underground. Since the start-up was founded in 2017, its technology has made its mark in several different sectors. Climeworks aims to eliminate 1% of global emissions by 2025.
As humanity sets out to save the planet and political decisions remain pending, will we have to keep pumping carbon dioxide (CO2) from the atmosphere to prevent the earth from turning into a furnace? The report of the Intergovernmental Panel on Climate Change (IPCC) of 8 October 2018 is clear: all scenarios to limit global warming to 1.5°C involve extracting atmospheric CO2 in huge volumes – between 100 and 1,000 billion tonnes by 2100 – which is two to twenty times the current annual total amount of global greenhouse gas emissions.
Boom in negative emissions
Removing CO2 from the atmosphere is what scientists call negative emissions. On paper, there are several ways to achieve this. The easiest way is to plant forests. Trees are very efficient carbon sinks, capturing CO2 through photosynthesis and storing it in their trunks, branches and roots, as well as in the soil. But to capture between 100 and 1,000 gigatonnes of CO2, we would have to plant a tropical forest twice the size of France, according to the IPCC. A second possibility is based on bioenergy. This consists in cultivating fast-growing plants. But here again, more than 700 million hectares would have to be devoted to these crops by 2050, which is unrealistic.
There is a third way that is emerging – using physico-chemical processes to capture atmospheric CO2 directly and then storing it underground. Several companies are exploring this avenue, such as the Swiss start-up Climeworks, which has developed a kind of giant vacuum cleaner to filter ambient air and trap carbon dioxide before injecting it underground. The Zurich-based company aims to eliminate 1% of global emissions by 2025. This far-from-ridiculous solution is the brainchild of Christoph Gebald and Jan Wurzbacher, two engineers from the Swiss Federal Institute of Technology Zurich (ETH Zurich).
900 tonnes of CO2 for greenhouses in Hinwil
In June 2017, the two Climeworks founders put their idea into action at a waste incinerator in Hinwil in the canton of Zurich. Eighteen CO2 sensors were fitted to the roofs at the plant. The sensors pump carbon dioxide from the atmosphere and filter it. This gas is then piped to a nearby greenhouse growing vegetables, which show a 20% increase in growth thanks to the extra CO2. The successful project is the result of several years of research. Climeworks is currently absorbing 900 tonnes of CO2 in Hinwil each year – the emissions equivalent of about 30 households.
The Zurich start-up's technology is also attracting attention abroad. In 2017, Climeworks set up a similar system in Iceland. Here, the CO2 is not used to grow vegetables but is trapped at a depth of 700m where, combined with a layer of basalt, it turns into white stone. The system currently removes 50 tonnes of CO2 per year, but its capacity will be increased to reach an annual target of 2,500 tonnes.
In August 2018, Climeworks raised CHF 30.5 million from private investors and the Zürcher Kantonalbank, which shows just how much interest the technology is generating. This sum should enable the company to meet a major challenge – reducing costs so as to be suitable for mass production. Climeworks currently spends between USD 600 and 800 on each tonne of captured CO2. By continuing to improve its sensors, the company is aiming to reduce this amount to USD 200 in the next three to four years, and to USD 100 in the long term.
Last October, Climeworks opened a third site in Apulia, Italy, as part of the European Union's Horizon 2020 research programme. Here, CO2 is combined with hydrogen produced using a renewable energy source – photovoltaic electricity – which produces natural gas that can be used as fuel for trucks. First Switzerland, then Iceland, and now Italy... In less than two years, Climeworks has succeeded in adding value and monetising CO2, and making it accessible to everybody.
Climeworks has already attracted several Swiss companies, including multinationals. It is collaborating on developing a non-fossil diesel with the German car manufacturer Audi, which has unveiled a pilot plant in Dresden for the project. Climeworks and Valser mineral water are also embarking on a joint venture whereby captured CO2 will be used to make the brand's sparkling water. Given the world's climate emergency, the two Climeworks founders are confident about the future of their company, which is already applying its solutions in a wide range of areas.