Alberta-based Carbon Engineering is inaugurating a pilot project today in Squamish, British Columbia, that will capture carbon dioxide (CO2) directly from the atmosphere. The company, funded by private investors, including Microsoft founder Bill Gates and oil sands financier Murray Edwards, has developed technology based on research conducted by Harvard University–based Professor David Keith’s research groups at the University of Calgary and Carnegie Mellon University.
The approach is one of a number of technologies (mostly concepts at this point) that are generally grouped under the label “geoengineering.” The argument against direct air capture has been that the CO2 concentration in the air we breathe is only about 0.04%, whereas the concentration emitted by a coal-fired power plant is around 10%, and post-combustion carbon capture projects—like the world’s first at an operating generation unit, SaskPower’s Boundary Dam Unit 3—enable the capture of a virtually 100% pure stream of the greenhouse gas. As with post-combustion carbon capture, Carbon Engineering’s process can create “pipeline quality” CO2 for industrial use.
The B.C. plant is designed to capture up to 1 million metric tons (mt) of CO2 per day and is located on a site, about an hour north of Vancouver, previously occupied by a Nexen chemical plant.
This new plant is also a chemical plant of sorts. As the company explains, “CE’s air contactor absorbs atmospheric CO2 into our capture solution to produce a liquid solution that is rich in CO2. The regeneration process, involving several processing steps, produces a purified stream of CO2 and re-makes the original capture chemical. These two processes work together to enable continuous capture of CO2 from atmospheric air, with energy (and small amounts of make-up chemicals) as an input, and pure CO2 as an output.”
One of the processing steps traps the captured CO2 into pellets of calcium carbonate. Some other researchers have considered stopping at that point and selling and/or burying that mineral. In Carbon Engineering’s process, the pellets are reheated to release pure CO2. The company notes in a July project update that, “Due to the tall, skinny nature of the pellet reactor vessel, coupled with the site’s seismic conditions,” a special foundation was required at the Squamish plant.
The province of B.C. has a program that puts a price on carbon, currently US$23/mt, according to a September World Bank Group report. Carbon prices elsewhere range from less than $1/mt (Mexico and Poland) to $130/mt (Sweden). The Toronto Star reported that Keith indicated that a price around $100/mt would make his company’s project commercially viable.
As with other carbon capture schemes, one of the largest challenges is making the process viable from both a cost and an energy input/output perspective. Typically, making those numbers work requires a marketable byproduct. Via Twitter, Keith said the company would also be announcing plans for an air-to-fuel demonstration project. That project would take captured CO2, add hydrogen (from renewable energy sources), and create a liquid transportation fuel. That plant, according to a CBC.ca story, is expected to be online in 2016 or 2017.
—Gail Reitenbach, PhD, editor (@GailReit, @POWERmagazine)