On June 28, the states of Wyoming and Colorado announced that they signed a Memorandum of Understanding (MOU) to focus on the development of direct air capture (DAC) technology and activity. DAC is a method of carbon dioxide removal in which CO2 is taken out of the atmosphere and sequestered in a controlled environment. Both Colorado and Wyoming lead the nation in DAC activity, and the bipartisan agreement between governors Mark Gordon and Jared Polis represents the first multi-state partnership of its kind in the country.
The MOU highlights such potential collaborations as applying for grants, developing carbon removal measurement standards, analyzing market opportunities and developing commercialization pipelines for new carbon-related technologies. This partnership hopes to mobilize $3.5 in funding from the Bipartisan Infrastructure Law’s Regional Direct Air Capture Hub program, designed to support four regional DAC projects across the nation.
DAC has been hailed as a method to possibly attain net-negative emissions sometime in the near future, meaning more CO2 is sequestered than emitted. While many industrial plants have carbon recapture technologies on-site, CO2 released from passenger vehicles or construction projects — two of the leading sources of greenhouse gas emissions in the Roaring Fork Valley — can’t be recaptured directly. However, by actively removing CO2 from the atmosphere, DAC can function in conjunction with renewable energy sources to potentially reverse emissions from these sources.
DAC technology can function either chemically or physically, but the most common form of DAC currently in use first uses large fans to suck ambient air through a filter. However, it isn’t a physical filter that separates CO2 from the air. Instead, most DAC units use a liquid solvent to absorb gaseous CO2 — commonly amines (derivatives of ammonia) or sodium hydroxide (better known as caustic soda or lye).
As a common example, sodium hydroxide reacts with the gaseous CO2 to form solid sodium carbonate, a chemical similar to baking soda. This sodium carbonate is separated from the liquid solvent and then heated to produce a highly pure stream of gaseous CO2. The CO2 is extracted, and the sodium carbonate is recycled to form more sodium hydroxide for the reaction to occur again. Once extracted, CO2 is ready for long-term sequestration — often deep underground — or packaged into gas tanks for industrial application.
This is simply one example of a common method of DAC, but most commercial techniques follow a similar method by using a liquid to absorb CO2 from the air. Some other techniques in development include using synthetic membranes, which use less water than a liquid solvent, or small, dispersed scrubbers instead of large, high-power facilities.
There are, however, problems with current commercial DAC technology. The liquid solvent process for CO2 absorption demands a high energy input in order to heat the array and requires a carbon-free source of electricity. If a DAC plant was powered by fossil fuels, the plant would end up releasing more CO2 into the atmosphere than it would absorb. The amine-based capture process also demands immense quantities of water — not a plentiful resource in either Wyoming or Colorado — and sodium hydroxide for the other process is highly caustic, meaning chemical spills could be disastrous. Furthermore, the technology and the power necessary for its function are expensive, and climatologists have argued that it would be more efficient to direct resources towards reducing CO2 emissions instead.
That being said, Colorado and Wyoming are global leaders in the practical application of DAC technology. In the spring of this year, U.S.-based company Global Thermostat unveiled one of the world’s largest DAC machines in Adams County, Colorado, with a CO2 adsorption capacity of more than 1,000 tons a year. Additionally, LA-based company Carbon Capture is building a DAC plant in Wyoming which is slated to become the world’s largest CO2 removal facility. Called Project Bison, the facility is expected to start operations within a year and endeavors to capture 5 million tons of CO2 annually by 2030 — orders of magnitude greater than any currently operational DAC project.
According to a press release, Colorado’s rapidly developing technology sector is especially poised to work with Wyoming’s already greatly developed energy workforce and infrastructure. The MOU signed between the two states could create a powerhouse of carbon capture in the Mountain West.
“This exciting bipartisan partnership builds upon our nation-leading work in Colorado to achieve 100% renewable energy by 2040 while adding good-paying jobs,” said Governor Polis.