Carbon dioxide freezes to carbon dioxide snow at -78.5 ° C. Israeli High Hopes wants to carry out the process in the cold at an altitude of 10-15 kilometers. They believe that one of their balloon rigs can collect a ton of carbon dioxide in 12-24 hours.
As part of its climate work, the EU is investing in CCS – “carbon capture and storage”. According to last year’s report from the Climate Policy Choice of Roads Inquiry, it is also necessary for Sweden to invest in CCS if we are to achieve our climate goals.
Then it is a matter of capturing the carbon dioxide at the source, such as chimneys at incineration plants or large industries. But there are also a number of projects around collecting carbon dioxide from the atmosphere – however, this is very expensive.
A price example comes from Swiss Climeworks, which absorbs carbon dioxide from the atmosphere. According to New Atlas The cost of Climework’s facilities is somewhere between just over SEK 5,000 and SEK 8,400 per tonne of carbon dioxide collected.
That price tag is now being challenged by High Hopes. The Israeli company claims that their high-altitude balloons can collect 1 tonne of carbon dioxide for SEK 840, and they believe that an upscaling can push the price to SEK 400-500 per tonne.
Their concept for the collection is based on carbon dioxide freezing to carbon dioxide snow at -78.5 ° C, and since the balloon is at an altitude of 10-15 km, this means that the process for cryogenic distillation requires very little energy. The rig would only consist of a part that increases the CO2 content slightly in the air that is taken in – as well as aluminum plates that are cooled to minus 80 degrees, where the carbon dioxide forms snowflakes.
Balloons filled with hydrogen
The dry ice ends up in pressure tanks and when the temperature rises at a lower altitude, the ice is converted to gaseous form in the tank. Then it’s a simple thing to bring the tank to the storage site. High Hopes intends to use the same balloons that took the decommissioned Loon project to record heights before it was shut down. In the basic version, it is estimated that a balloon will be able to collect one tonne of CO2 in 12-24 hours.
The balloons must be filled with hydrogen to get lift. The hydrogen gas will also be used to power the rig and the navigation system on board.
So far, High Hopes has only sent smaller test balloons that can carry a few kilos of cargo. The Loon balloons are manufactured by American Raven Aerostar, and they carry a load of 150-200 kg to a height of just over 20 km – but at the slightly lower height that High Hopes envisages, it is possible to increase the load to 300 kg.
The Israelis see it as likely that they will use an even larger balloon in the future, but those that exist today are not commercially available. Among other things, Nasa has balloons that can lift 1.5 tons of cargo. To capture one million tonnes of CO2 per year, 2,055 large balloons would be required, each carrying a tonne of cargo, and they would then have to go down to apply carbon dioxide every 18 hours.
The chosen technology certainly requires some ground staff, but the need remains roughly the same for scaling up. High Hopes hopes that in the future the company can meet some kind of tax change in the style of what we already have in Sweden.