While the world might be making the steady shift away from fossil fuel energy sources, there is concern that avoiding a climatological catastrophe might take more than simply halting our production of carbon dioxide waste, and that our civilization might need to start actively removing excess CO2 from the atmosphere. Numerous companies around the planet have been developing such an idea, a process called "carbon sequestration", including a Canadian company that is looking to do more than just remove carbon dioxide from the atmosphere: they plan to recycle the recovered greenhouse gas and use it as a carbon-neutral fuel source.
Funded by a number of government and sustainability-focused agencies, including private investors such as Microsoft founder Bill Gates, Carbon Engineering is developing, and indeed using, sequestering technology to actively pull CO2 out of the air using what the company calls an "air contactor", an installation that was built near the town of Squamish, British Columbia, in 2015. The air contactor is an end-to-end pilot plant designed to demonstrate the "Air to Fuels" concept, making use of solar power to run the plant, and water to capture the CO2. Combined with a number of other base chemicals, the captured carbon can then be used to produce low-carbon fuels for use in transportation, including analogues of gasoline, diesel, and jet fuel.
"The carbon dioxide generated via direct air capture can be combined with sequestration for carbon removal, or it can enable the production of carbon-neutral hydrocarbons, which is a way to take low-cost carbon-free power sources like solar or wind and channel them into fuels that can be used to decarbonize the transportation sector," explains Carbon Engineering founder David Keith. Keith is also the lead author of a study on the feasibility of low-cost carbon sequestration published in the energy science journal, Joule.
Previous studies had put a price tag on carbon sequestering endeavors such as this at roughly $900 to $1,000 per ton; Keith says that their process, once scaled up to a level that would make a meaningful impact, would only cost around $94-$232 per ton of CO2 collected. This makes the process of carbon sequestration more cost-attractive to industries that might be looking to take advantage of it, and also provide carbon-neutral liquid-based fuels for applications where converting to electricity might otherwise be impractical, or even prohibitive. Despite advances in battery technology, electricity "doesn’t allow us to make airplanes fly and trucks drive," according to Keith. Additionally, if the power being used in an electric vehicle was produced by a coal-fired power plant, then that vehicle could indirectly have a larger carbon footprint than a gasoline-powered vehicle.
While these synthetic fuels produced by Carbon Engineering’s concept would still produce carbon waste, these fuels, according to Keith, "didn’t come from the ground, so the amount of carbon they emit when they burn is just the amount you used making them, so they’re carbon neutral."
"Electricity from solar and wind is intermittent; we can take this energy straight from big solar or wind installations at great sites where it’s cheap and apply it to reclaim and recycle carbon dioxide into new fuel," Keith continues. "Making fuels that are easy to store and transport eases the challenge of integrating renewables into the energy system."
Carbon Engineering’s design also uses off-the-shelf industrial equipment, meaning sequestration plants can be built cheaply, and can be expected to produce approximately 2,000 barrels of fuel per day.