The idea is simple: equip each train with a few wagons with large air scoops and an installation for direct air capture (DAC). This is a young technology to reduce CO2to grab and store molecules from the air. At stations, the CO2 can be pumped into larger tanks or pipelines, after which it can be reused by industry for the production of, for example, synthetic kerosene. Or the carbon dioxide will be stored underground for good.
Mobile CO2capture is promising, according to a publication that appeared on Wednesday in the scientific journal Joule: a train equipped with a climate wagon can produce six thousand tons of CO . per year2 pluck from the atmosphere. That is about as much as two thousand Dutch petrol cars emit per year.
If this technology is used on a large scale, the price per ton could be around $50, the researchers believe. That is considerably less than the European CO2-price of almost 75 euros. So a business model seems possible. According to the researchers’ forecasts, almost half a gigatonne of CO . could be released by 20302 from the atmosphere, rising to 2.9 gigatons in 2050. By comparison, nearly 37 gigatons were blown into the air worldwide in 2019.
Extra wagon to freight train
‘It is good that more attention is being paid to direct air capture,’ says associate professor David Vermaas, who is researching it at TU Delft. ‘But when applied to a train, I still have doubts.’
According to Vermaas, capture in a fixed installation is easier to realize, partly because infrastructure is lacking at stations to collect CO .2 to collect and dispose of. The researchers mention in Joule The advantage is that a train is less affected by the nimby effect: people prefer not to have installations in their neighbourhood, even if they help the climate. Nobody has any objections to an extra wagon on a long freight train, is the idea.
Vermaas did prick up his ears when he learned that the researchers want to use an electrochemical process to convert CO2 from the adsorbent in which it is stored during the capture process. Current processes require a lot of energy (for example because steam is needed), an electrochemical variant can produce CO2make capture much more efficient.
‘This is still in its infancy, but it fits much better into the sustainable energy transition’, says Vermaas. ‘And more and more scientists are convinced that DAC is necessary to keep the global temperature rise below 1.5 or 2 degrees Celsius.’
Eindhoven University of Technology
The idea for mobile CO2-capture has arisen in more places: students from Eindhoven University of Technology will present an electric car with built-in CO . on Thursday2-sponge. Thanks to their discovery, the car is officially climate negative. A little bit, indeed, because Zem, as the vehicle has been christened, captures less than two kilograms of carbon dioxide per year with average car use.
The students hope to increase capacity and are mainly aiming for scale: more than a billion cars are on the road worldwide. Zem is a concept, the students say, intended to show what is possible. Team member Nikki Okkels: ‘We want to tickle the industry.’
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