TRAINS COULD SUCK CO2 OUT OF THE AIR AS THEY CROSS THE COUNTRY

A single train fitted with the system could remove thousands of tonnes of carbon every year

Choo choo! The air-cleaning system could be fitted onto freight trains

Retrofitting direct air capture technology to trains to recover CO2 could help us get back on track in the fight against climate change, a study carried out at the University of Toronto has suggested.

Direct air capture systems typically extract CO2 from the atmosphere via a series of chemical reactions that occur as air passes through them. This captured CO2 can then be stored in a liquid reservoir until it can be sequestered underground in porous rock formations. The technology is already well established, but stationary, ground-based facilities require a lot of land. This has historically led to residents in the areas near to proposed sites objecting to their construction, the researchers say.

“It’s a huge problem because almost everybody wants to fix the climate crisis, but nobody wants to do it in their backyard,” said co-author Prof Geoffrey Ozin, director of the solar fuels group at the University of Toronto.

“Rail-based direct air capture cars would not require zoning or building permits and would be transient and generally unseen by the public.”

The team’s proposed design could be fitted to existing trains and uses a large vent to take in air. This makes it much more efficient than the energy intensive fan systems used in stationary facilities.

According to their calculations, the researchers say that an average freight train fitted with their system could remove as much as 6,000 tonnes of carbon dioxide per year – an amount comparable to that emitted by 250 medium-sized family cars over their lifespans.

It would also be significantly cheaper to operate than other currently available direct air capture systems and would require far less construction work than stationary facilities, as the rail network is already in place.

“The infrastructure exists,” said Ozin. “That’s the bottom line. All you need to do is take advantage of what is already available.”