Next stop net zero for train that filters carbon dioxide from air

CARBON-CAPTURE trains, which suck up emissions as they go, could one day help tackle climate change.

Engineers have joined a US company to design air-cleaning wagons which can be slotted easily into existing trains.

They would cut environmental damage from railway engines and have extra capacity to pull carbon dioxide directly out of the air, bringing reductions in atmospheric CO2.

“Imagine stepping on to a train each morning, seeing the Co2rail cars attached, and knowing that your commute to work each day is actually helping to mitigate climate change,” said Eric Bachman of the Co2rail Company.

Current static carbon-capture systems need energy intensive fans to move polluted air into collection chambers, but the new carriages take advantage of the slipstream of moving air generated as a train goes along a track.

The fumes are filtered into a collection chamber where they move through a chemical process which separates carbon dioxide, returning clean air back into the atmosphere.

The harvested CO2 is collected, concentrated, and stored in a liquid reservoir until it can be emptied and transported into the carbon economy where it could, for example, be pumped into greenhouses to help plant growth.

To make the process even more efficient, the carbon-capture carriages are powered using energy generated when trains brake and decelerate, which is currently vented as heat.

Prof Peter Styring, director of the UK Centre for Carbon Dioxide Utilisation at the University of Sheffield, said: “The direct capture of carbon dioxide from the environment is increasingly becoming an urgent necessity.

“Currently the enormous amount of sustainable energy created when a train brakes or decelerates is simply lost.

“This technology will not only use the sustainable energy created by the braking manoeuvre to harvest significant quantities of CO2, but it will also take advantage of many synergies that integration within the global rail network would provide.”

In a paper in the journal Joule, the team found each car could harvest 6,000 tons of carbon dioxide a year, the equivalent of the electricity carbon footprint of 3,900 European households.