What would be petrolhead nirvana? Perhaps a process that sucked excess carbon dioxide out of the atmosphere, and converted it to liquid fuel that could be cleanly burned in modern internal combustion engines?
We’ve previously discussed efforts being made in Europe to achieve just this, with Bosch, among others, deeply involved. However the process involved at the moment is quite expensive, although better economies of scale could improve this.
But what if someone could come up with a process that would do it cost-effectively?
Well, a Canadian company, Carbon Engineering (CE) says it’s done that, and its findings are based on the practicality of running a pilot plant for three years.
Its DAC (Direct Air Capture) is a technology that processes atmospheric air, removes CO2, and purifies it. CE’s DAC technology does this in a closed loop where the only major inputs are water and energy, and the output is a stream of pure, compressed CO₂.
This captured, compressed CO₂ then offers a range of opportunities to create products and environmental benefits, including CE’s main focus, production of clean-burning liquid fuels with ultra-low carbon intensity.
“At CE, we have been developing our DAC technology since 2009 and capturing CO2 from our pilot plant in Squamish, British Columbia, since 2015,” says the company.
CE’s vision is for industrial-scale DAC facilities, built outside cities and on non-agricultural land. Individual DAC plants can be placed in any country and in multiple climates, and can be built to capture one million tons of CO2 per year.
At this large scale, says CE, its technology will be able to achieve costs of US$100-150 per ton of CO₂ captured, purified, and compressed to 150 bar.
This compares very favourably to European estimates that it would cost US$600 per ton to remove CO2 from the atmosphere using DAC technology, making it too expensive to be a feasible solution to removing legacy carbon at scale.
CE’s pilot plant consists of an industrial cooling tower which has been redesigned so it takes CO2 from the air, changes it from a gas to a solid, and then back to a purified gas.
The process uses a calcium hydroxide solution to capture the CO2, and converts it into solid calcium carbonate that is then formed into pellets, which are in turn heated in an industrial kiln to produce a pure carbon dioxide gas. That gas can then form the basis of a synthetic fuel.
The company has developed a process it calls Air To Fuels, which uses water electrolysis and fuels synthesis techniques to turn that pure CO2 into liquid hydrocarbon fuels. CE says these fuels are compatible with existing transportation infrastructure.
“This technology forms an important complement to electric vehicles in the quest to deliver carbon-neutral 21st Century transportation,” says CE.
“While short haul transportation is amenable to electrification, longer haul transport, as well as marine and air travel, require the high energy density of liquid fuels (liquid fuels like diesel have an energy density 30 times greater than today’s best batteries).
“The Air To Fuels process offers a way to deliver these fuels, while avoiding the infrastructure turn-over of hydrogen fuel cells, and avoiding the land use and food security problems associated with biofuels.”
CE says this clean fuel is fully compatible with existing engines, so it provides the transportation sector with a solution for significantly reducing emissions, either through blending or direct use. The technology is scalable, flexible and demonstrated.
CE is privately owned and is funded by private investors, including Bill Gates and Murray Edwards, and with support from governments. CE grew from academic work conducted on carbon management technologies by Prof. David Keith’s research groups at the University of Calcary in Canada and Carnegie Mellon University in the US.
