CLIMEWORKS has opened what it says is the world’s first commercial plant to directly filter and capture CO2 from the atmosphere in Hinwil, near Zurich in Switzerland.
The direct air capture (DAC) plant has been installed on the roof of a waste utilisation plant run by regional municipal waste recovery firm KEZO, which burns non-recyclable waste to recover the energy from it. The DAC plant captures CO2 directly from the ambient air, which is purified and piped directly to greenhouses 400 m away owned by Gebrüder Meier Primanatura, an agricultural company. Crops such as tomatoes and cucumbers grow up to 20% larger when CO2 is added to the greenhouses, making the greenhouse gas a valuable, saleable resource. The supply deal with Gebrüder Meier Primanatura is crucial to the DAC plant’s commercial viability.
Climeworks’ technology is based on a solid filter material modified with amines, the exact details of which the company has not disclosed. A bank of fans suck surrounding air into the plant. The air passes through 18 collectors. The CO2 binds to the amines on the surface of the filters as it passes through the collectors. Once the filters are saturated, which takes a few hours, low-grade waste heat from the KEZO plant is used to heat the filters to 100°C, which releases the CO2, which is then captured and piped to the greenhouses. The filters are reusable for several thousand adsorption and desorption processes, according to Climeworks. The plant will capture around 900 t/y of CO2 for the greenhouses.
Climeworks spokesperson Valentin Gutknecht told The Chemical Engineer that one of the main goals of the plant will be to determine the exact cost of CO2 capture in a plant in continuous operation
“We expect costs at about US$600/t of CO2. With that cost we are competitive as of today in remote regions such as islands and parts of Africa where industrial CO2 needs to be trucked over long distances to bring it from emissions sources (eg ammonia production) to customers (eg soda bottling plants). We are currently working on the next generation of our technology through which we expect to cut cost by 50%. The long term cost target which we see achievable is below US$100/t of CO2,” Gutknecht added.
Climeworks believes that captured CO2 could one day be sold to various markets other than agriculture, including food and beverage industries, the energy sector and the automotive industry, lessening dependence on fossil fuels for CO2. The company plans to open further commercial pilot projects in the coming months, and will use the data and experience from the Hinwil plant to improve the process.
“Highly scalable negative emission technologies are crucial if we are to stay below the 2°C target of the international community,” said Christoph Gebald, co-founder and managing director of Climeworks. “The DAC technology provides distinct advantages to achieve this aim and is perfectly suitable to be combined with underground storage. We’re working hard to reach the goal of filtering 1% of global CO2 emissions by 2025. To achieve this, we estimate around 250,000 DAC plants like the one in Hinwil are necessary.”
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