For a few months now, the first commercial factory has been in operation that extracts CO2 from the air and passes it on to businesses and consumers. The company behind the factory, Climeworks, aims to capture 1 per cent of global CO2 emissions by 2025. Could this help reduce global warming?
The so-called Direct Air Capture (DAC) factory uses a patented technology that extracts carbon dioxide from the ambient air with a filter. The developers say the factory can capture about 900 tonnes of CO2 a year (about the amount of emissions from 200 cars). The gas is sent to a nearby 'greenhouse' to grow vegetables.
The plant is a historic step in negative emissions technology; an important way to limit global warming, as stipulated in the Paris climate agreement.
First step
Although the amount of CO2 is only a small fraction of what companies and climate activists hope to capture in large fossil fuel plants, Climeworks says its iniative is a first step in the goal of capturing 1 per cent of global CO2 emissions with a similar technology. To do that, there would need to be 250,000 plants of the same kind.
"Scalable negative emission technologies are crucial if we want to stay below the 2 degree global warming target," states Christoph Gebald, co-founder of Climeworks. Located on top of a waste heating plant, fans push air through a filter system that collects CO2. When the filter is saturated, CO2 is separated at temperatures above 100 degrees Celsius. The gas is then sent through an underground pipeline to the greenhouse, where it helps grow vegetables such as tomatoes and cucumbers.
Expensive
Developers say the CO2 could have many more applications, such as carbonating drinks. The two set up Climeworks in 2009 after working on capturing air during their studies. They plan to run the new plant for three years as a demonstration project. In 2018, the company plans to launch additional commercial ventures, including some that bury gas underground to achieve negative emissions. "With the energy and economic data from the plant, we can make reliable calculations for other, larger pojects," he said.
Although the founders of Climeworks believe in their technology, there are also sceptics when it comes to technologies to filter CO2 from the air. They argue that it is cheaper to capture carbon dioxide directly in fossil fuel plants and ensure that CO2 does not get into the air at all. Capturing air is quite expensive partly because CO2 in the air is diffuse, while it is more concentrated in the stream of a fossil fuel plant.
Climeworks did receive financial help from the Swiss Federal Office of Energy and the European Union, among others.
In the video below - somewhat commercial - Audi, which helped build the Climeworks plant, explains how the CO2 filtering process works:
By: Kelly Bakker
Source: Climeworks, Science Mag
