“It took 10 years of work to get here,” said Paul Nahi, CEO of Global Thermostat.
He’s speaking about the company’s direct air capture (DAC) demonstration plant in Brighton, Colorado, in early April. The event brought out former Speaker of the House Nancy Pelosi, Colorado Governor Jared Polis and several White House officials, among others.
“It’s exhilarating,” said Nahi. “And it represents a massive financial opportunity for many people in the broader ecosystem.”
Unlike point source carbon capture, the DAC process separates CO2 from ambient air.
Global Thermostat’s demonstration plant is a cube-shaped warehouse that works like a chemical filter. Fans in the walls draw air through filters coated with a solvent that grabs the carbon. Injected low-temperature steam then pulls out the carbon, releasing carbon-free air back into the atmosphere.
In the future, companies may pay Global Thermostat for the carbon to use as a feedstock for industries like concrete, agriculture, food and beverage or fertilizer. The carbon could also be sequestered underground. It would generate a certain number of carbon credits, which would be sold to emitting companies trying to reach net-zero.
But for now, there is no sequestering. The CO2 captured by the demonstration plant is being released back into the atmosphere. How and where to store, compress and transport the carbon once it’s been captured is still being worked out.
“For now, it’s more about the demonstration of the technology,” said Nahi.
There are many hurdles to clear. For one, direct air capture is expensive. Global Thermostat officials say the next steps are to find ways to reduce the costs and increase the efficiency of the system, from the contactor to the sorbent to the mechanical design.
“What we have is proof that we can capture the carbon, we can pull it out of the atmosphere,” he said. “Now we need to scale it.”
The demonstration plant in Colorado is powered by grid electricity and heat from a natural gas boiler, company officials said.
From an energy standpoint, the thermal needs represent around 80% of the system’s total energy needs. That’s why co-locating a system with a nuclear power plant is an option down the road.
“We’ve been in discussions with entities that are talking about putting it co-located with a nuclear power plant or with other power generation facilities,” said Nahi. “The advantages there are waste heat, to reduce our energy usage.”
Recent analysis from The Great Plains Institute identified seven regions in the United States offering the best characteristics to house a direct air capture hub.
Multiple nuclear plants, including Southern Company’s Joseph M. Farley plant in Columbia, Alabama and Constellation’s Byron plant in Northern Illinois will host direct air capture (DAC) studies with funding from the U.S. Department of Energy.
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