CO2 could be captured directly from truck exhausts
Image credit: Ruben de Rijcke
Researchers based at Switzerland’s École Polytechnique Fédéralede Lausanne (EPFL) have proposed a method for reducing the carbon emissions of trucks by 90 per cent with a small system which can be retrofitted to existing vehicles.
In Europe, transportation is responsible almost 30 per cent of total carbon e missions, of which most (72 per cent) comes from road transportation. As the world struggles to decarbonise in order to keep global average temperature rises to within 2°C, cutting down on emissions associated with transport has become a priority.
While a push towards electric and low-carbon personal vehicles will play a large part in decarbonising transport, reducing emission associated with public and commercial transport, such as trucks, remains a more stubborn challenge.
EPFL engineers suggest that trucks drivers could cut their emissions by a factor of 10 using a patented system which captures carbon straight from the exhaust, and liquifies it to be stored in a box on the roof.
By cooling the vehicle’s flue gases, it is possible to separate water from the gases, and then isolate the CO2 from the nitrogen and oxygen in the fumes with a temperature swing absorption system, which uses frameworks designed at EPFL to absorb CO2. Once the system is full of CO2, it is heated (using heat from the vehicle’s engines) to extract pure CO2, which is then compressed into a liquid. This liquid can be stored in a tank and transported to a service station to be turned into conventional fuel, via a process powered by renewable energy.
“The truck simply deposits the liquid when filling up with fuel,” said Professor François Maréchal, who led the project.
The entire process can be carried out within a capsule of 2x0.9x1.2m, which can be placed above the driver’s carbon. According to Maréchal, the weight of the capsule and tank is just seven per cent of the vehicle’s payload: “The process itself uses little energy, because all of its stages have been optimised.”
A truck using 1kg of conventional fuel could produce 3kg of liquid CO2, the researchers estimate. Just 10 per cent of the vehicle’s total CO2 emissions cannot be repurposed.
Although the researchers focused on a delivery truck in this study, this method could theoretically work with all sorts of other vehicles, including buses and boats, and with any type of fuel. Unlike electric and hydrogen-based systems, this system can be retrofitted to existing trucks to almost neutralise their contribute to climate change.
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