Episode 74 | Suspending Structures | Mosaic Materials
This year marked the first time my alma mater, LSU, had an undefeated regular season since 1958. While cheering on this incredible run at home, I was also excited to see carbon capture commercials from ExxonMobil. The commercial represents a multi-million dollar effort by the company to develop lower emissions technologies.
In August 2019, ExxonMobil announced an agreement with Mosaic Materials to help develop the young company’s CO2 absorption technology. Mosaic was founded in 2015 by researchers at UC—Berkeley. My guest, Mosaic co-Founder and CEO Dr. Thomas McDonald, says he first began working on the underlying technology while working as a grad student.
CO2, he says, can be absorbed using a Metal-Organic Framework technology. Air passing through the material will selectively capture CO2. Heat or pressure will release the CO2, producing a concentrated amount of CO2 to be stored.
Thomas says they discovered MOFs could interact with CO2 in 2011. The core technology has the consistency of a salt or powder but can be molded into a solid like a pellet. He says the pellets are mostly empty space, which can hold the carbon dioxide molecules.
MOFs bind CO2 using a "cooperative absorption mechanism." Thomas compared it to the way hemoglobin in the blood binds oxygen. He also adds that "Once you start to capture CO2, it actually becomes more and more efficient to capture the next one."
Thomas calls Mosaic "a materials company first," adding that they are working with other firms like Exxon to develop a system that would effectively house the MOFs and efficiency capture/release the CO2.
"A really important part of the engineering work that goes into the application is what is the most efficient way to heat up and cool down that material," he says.
He also adds that pressure could release CO2 as well. For the process to work at a power plant, exhaust flue gas must be "chilled" to 40-60°C (104-140°F). Flue gas in the U.S., he says, is generally cooler at this stage because it has been treated with sulfur scrubbers. He believes waste heat from the power plant could heat these pellets back up for desorption.
Thomas believes a post-combustion power plant could be a few years away. For now, he believes the company's immediate future rests in "natural gas sweetening," or removing CO2. Like my guest from Episode 64, he believes an affordable sweetening solution could reduce oilfield gas flaring. He adds that landfill gas is especially high in CO2.
"I think that Exxon is interested in advancing the technology readiness of a range of carbon capture solutions," says Thomas, adding that Fuel Cell Energy and Global Thermostat have been other recent beneficiaries of the company’s low-carbon initiatives.
"I'm a huge believer in solar and wind, but I also believe fossil fuels are not going away anytime soon," he says. "It's really important that we find solutions to deal with CO2 emissions we know we are going to emit for the next century."
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