Climate change is one of the most urgent, and complex, challenges of our time. In order to preserve our planet’s eco-system, we must spend the next ten years dramatically reducing our net emissions of carbon dioxide, while continuing to sustain a growing population.
The latest report of the Inter-Governmental Climate Change Committee is clear that to achieve the targets will take a combination of reducing our emissions with finding ways of removing the carbon dioxide already in the atmosphere. Carbon capture and storage/sequestration (CCS) is therefore a vital part of any country’s Net Zero strategy.
Direct air capture technology is very much part of a portfolio of solutions. It’s not a silver bullet in any way: the scale of the climate crisis is such that we need all solutions working together.Louise Charles, Communications Manager, Climeworks.
Much of the technology for carbon capture and sequestration has existed for decades. One example is direct air capture, but the problem has always been one of scale.
Climeworks was founded to develop large-scale direct air capture plants in order to tackle this challenge.
Founded by two Swiss mechanical engineers who studied direct air capture at ETH Zurich, Climeworks has developed large-scale direct air capture plants based on a modular system of CO2 collectors. These collectors, each the size of a small car, can be stacked in any number of configurations to create a plant of any size that extracts CO2 from ambient air.
To remove the CO2, fans draw air into the plant, where a highly selective filter material binds the CO2 in conjunction with the moisture in the air.
Once the filter is saturated with CO2 it is heated to around 100°C (212°F). This breaks down the bond between the filter and the CO2, which is released and collected as concentrated CO2 gas.
CO2-free air is released back into the atmosphere. This continuous cycle is then ready to start again. The filter is reused many times and lasts for several thousand cycles.
The CO2 can then be sold for making fizzy drinks, carbon-neutral fuels or used as fertiliser. It can also be stored underground by injecting a mix of CO2 and water into suitable rock formations, where a chemical reaction turns the CO2 into stone via the CarbFix process.
The only requirement for the process is a source of renewable energy, and if the CO2 is to be stored rather than sold, a suitable geological site to store it.
Climeworks plants are currently 90 percent efficient, emitting 10kg of CO2 for every 100kg removed from the atmosphere. The aim is to increase this to 96 percent through further innovation.
The company holds several patents on its technology, and is positive about their worth in terms of protecting its knowledge and helping to secure investment. Originally funded through accelerator programs and research grants, the company span out of ETH in 2009 to become a private company and has thus far secured investments of CHF 50 million.