Carbon Engineering

Direct air capture is the hardest version of carbon removal: instead of scrubbing concentrated flue gas from a smokestack, you pull CO2 out of ambient air, where it sits at roughly 420 parts per million — a needle-in-a-haystack chemistry problem that most people assumed would always be too expensive to matter. David Keith, a physicist then at the University of Calgary and later Harvard, thought otherwise, and in 2009 he founded Carbon Engineering to prove it at engineering scale. Early capital came from Bill Gates and from Murray Edwards, the Canadian oil-sands investor — an alignment of climate philanthropy and fossil money that would foreshadow the company's entire arc. From a site in Squamish, British Columbia, the company set out to build not a science demo but a process that could be licensed and replicated.

Carbon Engineering's approach used giant fan-driven air contactors to draw ambient air across a potassium hydroxide solution that grabbed the CO2, then a series of chemical steps to concentrate it into a pure stream ready for storage underground or conversion into fuel. In 2015 it commissioned a pilot plant in Squamish; in 2017 it added an AIR TO FUELS demonstration, combining captured CO2 with hydrogen to make synthetic, drop-in gasoline, diesel and jet fuel. The turning point was a 2018 peer-reviewed paper in Joule that laid out a detailed engineering cost for air capture — figures in the range of $94 to $232 per tonne — that was far lower than the field's prevailing assumptions and reset the entire conversation about whether DAC could ever be affordable.