This All-In-One Solar Tower Wants To Make All Jet Fuels Carbon-Neutral

In an extraordinary breakthrough, researchers have come up with a fuel production system that turns water, carbon dioxide, and sunlight into aviation fuel, in what could be the key to significantly reducing the industry’s carbon footprint. 

While not as detrimental as the fashion industry, the aviation sector is still responsible for 2% to 5% of global emissions. And while many companies are working on a cleaner alternative to kerosene—a fuel derived from crude oil—there hasn’t been one able to power long-haul commercial flights worldwide. 

“We are the first to demonstrate the entire thermochemical process chain from water and CO2 to kerosene in a fully-integrated solar tower system. With our solar technology, we have shown that we can produce synthetic kerosene from water and CO2 instead of deriving it from fossil fuels,” explained Professor Aldo Steinfeld from ETH Zurich.

“The amount of CO2 emitted during kerosene combustion in a jet engine equals that consumed during its production in the solar plant. That makes the fuel carbon-neutral, especially if we use CO2 captured directly from the air as an ingredient, hopefully in the not-too-distant future,” he added.

The team behind this incredible project had began working on the solar-fuel production plant in 2017, choosing to test the idea at the IMDEA Energy Institute in Spain. Featuring 169 sun-tracking reflective panels, the plant redirects solar radiation into a reactor at the top of the tower, which then gives rise to oxidation-reduction (redox) reaction cycles. 

Within the reactor, which comprises a porous material made out of an infinitely-recyclable ceria, water and carbon dioxide are converted into syngas, or a mixture of hydrogen and carbon monoxide, which is then fed into a gas-to-liquid convertor to become kerosene and diesel. 

During the nine-day test run, the solar reactor performed at 4% energy efficiency, the percentage at which solar energy input was converted into liquid fuel output. Going forward, the team hopes to make improvements to the design to amp up the efficiency to over 15%.

“This solar tower fuel plant was operated with a set-up relevant to industrial implementation, setting a technological milestone towards the production of sustainable aviation fuels,” remarked Steinfeld.

[via Interesting Engineering and ETH Zurich / Scimex, cover image via IMDEA Energy]