Direct Air Capture
For hundreds of millions of years, plants have been harnessing the power of photosynthesis to capture carbon dioxide from air and transform it into biomass. Recently, humans have attempted to engineer a similar feat through direct air capture (DAC) systems. The long-term hope: To use DAC to help achieve and maintain drawdown.
DAC machines act like a two-in-one chemical sieve and sponge. Ambient air passes over a solid or liquid substance; its carbon dioxide binds with chemicals in the substance that are selectively “sticky,” while other gases in the air are free to go. Once those capture chemicals become fully saturated with carbon dioxide, energy is used to release the molecules in a purified form.
The fundamental challenge is showing that DAC can be done efficiently and cost effectively. In the near term, the purified carbon dioxide released from DAC units could be used in a wide range of manufacturing applications from synthetic transportation fuels to the creation of plastics, cement, and carbon fiber. Others are looking to use atmospheric carbon dioxide in greenhouses to improve indoor agricultural yields. Eventually, DAC could help clean up carbon dioxide from the atmosphere as a sequestration technology.
“mine the sky”: Deich, Noah, and Giana Amador. “How to Build a Billion-Dollar Industry to Fight Climate Change.” GreenBiz. March 31, 2016. https://www.greenbiz.com/article/how-build-billion-dollar-industry-fight-climate-change.
[cost] per ton of carbon dioxide: Deich, Noah. “Socratic Dialogue on Direct Air Capture.” Center for Carbon Removal (blog). March 9, 2016. http://www.centerforcarbonremoval.org/blog-posts/2016/3/6/socratic-dialogue-on-direct-air-capture.
Additional Background Sources
Broecker, Wally. “Does Air Capture Constitute a Viable Backstop Against a Bad CO2 Trip?” Elementa 1 (2013).
Deich, Noah. “Direct Air Capture Explained in 10 Questions.” Center for Carbon Removal (blog). September 24, 2015. http://www.centerforcarbonremoval.org/blog-posts/2015/9/20/direct-air-capture-explained-in-10-questions.
Deich, Noah. “Socratic Dialogue on Direct Air Capture.” Center for Carbon Removal (blog). March 9, 2016. http://www.centerforcarbonremoval.org/blog-posts/2016/3/6/socratic-dialogue-on-direct-air-capture.
Goeppert, Alain, Miklos Czaun, GK Surya Prakash, and George A. Olah. “Air as the Renewable Carbon Source of the Future: An Overview of CO2 Capture from the Atmosphere.” Energy & Environmental Science 5, no. 7 (2012): 7833-7853.
Gunther, Marc. “Rethinking Carbon Dioxide: From a Pollutant to an Asset.” Yale Environment 360. February 23, 2012.
Gunther, Marc. “Startups Have Figured Out How to Remove Carbon from the Air. Will Anyone Pay Them to Do It?” The Guardian. July 14, 2015.
Kintisch, Eli. “Can Sucking CO2 Out of the Atmosphere Really Work?” MIT Technology Review. October 7, 2014.
Lackner, Klaus S., Sarah Brennan, Jürg M. Matter, A-H. Alissa Park, Allen Wright, and Bob van der Zwaan. “The Urgency of the Development of CO2 Capture from Ambient Air.” Proceedings of the National Academy of Sciences 109, no. 33 (2012): 13156-13162.
Lavelle, Marianne. “Out of Thin Air: The Quest to Capture Carbon Dioxide.” National Geographic. August 12, 2011.
McLaren, Duncan. “A Comparative Global Assessment of Potential Negative Emissions Technologies.” Process Safety and Environmental Protection 90, no. 6 (2012): 489-500.
Nemet, Gregory F., and Adam R. Brandt. “Willingness to Pay for a Climate Backstop: Liquid Fuel Producers and Direct C02 Air Capture.” The Energy Journal 33, no. 1 (2012): 53-82.
Plumer, Brad. “It’s Time to Look Seriously at Sucking CO2 out of the Atmosphere.” Vox. July 13, 2015.
Socolow, Robert, Michael Desmond, Roger Aines, Jason Blackstock, Olav Bolland, Tina Kaarsberg, Nathan Lewis et al. Direct Air Capture of CO2 with Chemicals: A Technology Assessment for the APS Panel on Public Affairs. College Park, MD: American Physical Society, 2011.