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Drop in driving endangers CO₂ supply

Gasoline demand is half of normal, idling ethanol plants and cutting off the CO2 they produce

by Craig Bettenhausen
April 22, 2020 | A version of this story appeared in Volume 98, Issue 16


A large tank of liquid carbon dioxide.
Credit: Craig Bettenhausen/C&EN
This liquid CO2 tank at Baltimore's Peabody Heights Brewery normally lasts about a month and a half.

People aren’t driving much right now. According to the US Energy Information Administration, gasoline consumption is around 50% lower than it was at this time last year. Although that’s a win for the environment, it’s a big problem for ethanol producers and a threat for beverage makers that depend on CO2 created during ethanol fermentation.

Most gasoline in the US contains 10% ethanol, almost all made from corn. In normal times, more than 60 billion L of ethanol go into motor fuel per year, but the drop in driving, attributable to the COVID-19 epidemic, has cut that figure in half, according to the Renewable Fuels Association. As a result, 70 of the US’s roughly 200 ethanol plants are idle, and another 70 are operating at reduced rates.

Fuel-ethanol makers that can meet the purity standards for hand sanitizer are trying to address shortages of alcohol in that market, RFA chairman Neil Koehler says. But those volumes aren’t even close to enough to stave off plant closures, he says, and shifting sanitizer regulations make supplying that market hard.

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It’s not just fuel-ethanol producers and the farmers that supply them with corn who are worried. Fermentation at ethanol plants normally contributes 37% of the US carbon dioxide supply, according to John Raquet, publisher of Gasworld magazine. On top of that, ammonia plants, which supply another 20%, are mostly offline because the fertilizer season is over for farmers.

Beer breweries and soft drink makers are the second-biggest customers for CO2, just behind the refrigeration industry, and they’re bracing for a hit.

“Here comes this potential supply chain disruption for an absolutely essential ingredient in beer,” says Charlie Berger, cofounder of Denver Beer Company. “CO2 and beer go hand in hand.” It provides the fizz for beer and soda; bars and restaurants use it to dispense beer. Brewing does generate CO2 as a by-product, Berger says, but most small breweries buy it as a refrigerated liquid because they don’t have the equipment to capture and reuse it.

Major companies have the clout and contracts to make sure they get the CO2 they need. “We are aware that the US is currently seeing less production of CO2,” Coca-Cola tells C&EN, adding that it does “not foresee any concerns about supply at this time.”

Smaller firms, in contrast, often just shop around for the lowest-price supplier when they need to refill their CO2 tanks. That strategy, Raquet notes, doesn’t work in a tight market where customers with contracts get served first. CO2 is a small component in beer and soda, so price increases won’t have much of an effect, he says. “But if the tanks are empty, the tanks are empty.”


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