Dwindling supplies of carbon dioxide from ethanol plants is sparking concern about shortages of beer, soda and seltzer water — essentials for many quarantined Americans. Brewers and soft-drink makers use carbon dioxide, or CO2, for carbonation, which gives beer and soda fizz. Ethanol producers are a key provider of CO2 to the food industry, as they capture that gas as a byproduct of ethanol production and sell it in large quantities. But ethanol, which is blended into the nation’s gasoline supply, has seen production drop sharply due to the drop in gasoline demand as a result of the COVID-19 pandemic....