Storm Lake Times Pilot

Ethanol leaves big carbon footprint

Little Sioux ethanol plant belches out far more than Tyson’s meatpacking plant


Carbon emissions from ethanol plants in Buena Vista and surrounding counties increased 7% in 2021, according to recently released data from the Environmental Protection Agency. 

Carbon emissions from six ethanol plants contributed 842,411 metric tons of CO2 in 2021, the EPA data shows. The year before the same plants emitted 783,833 metric tons. The increase can be attributed as a direct result of ethanol production, which has increased locally since the height of the coronavirus pandemic, according to Little Sioux Corn Processors General Manager Steve Roe. 

“Carbon dioxide is a direct result of production. I can’t speculate about our emissions, but if they were to increase, I’d say it had to do with production. It’s the only thing I can think of,” Roe said on Monday. Little Sioux Corn Processors emitted 190,000 metric tons of carbon dioxide in 2021, 3.7% higher than its overall emissions level in 2020. 

The EPA data shows Little Sioux has the largest carbon footprint of any industrial facility in the surrounding area. The only facilities with similar footprints in the area are other ethanol plants. Valero Ethanol’s facility in Hartley is the second-largest carbon-dioxide emitter with 188,000 metric tons. Valero’s plant in Albert City, which produces 135 million gallons of ethanol per year, emitted 157,000 metric tons. 

The only other area contributors that were reported by the EPA’s Greenhouse Gas Reporting Program were Tyson’s Storm Lake pork plant, Ag Processing in Emmetsburg and Corn Belt Power Cooperative’s Earl F. Wisdom power plant in Spencer. Of those industrial sources, Tyson was the largest contributor with 32,000 metric tons, the EPA data shows. 

Roe acknowledged the ethanol industry’s emissions might seem staggering, but carbon-dioxide is a necessary byproduct of ethanol production. Ethanol is fermented through a process that converts sugar into cellular energy, which produces ethanol and carbon-dioxide. 

“There aren’t very many ways you can tinker with this process,” explained ISU Economist Chad Hart. Hart noted the industry has diversified into capturing their CO2 byproducts into bottling, firefighting products and other petroleum-based products. Hart guessed emissions on a plant-by-plant basis vary by the year depending on whether the plant found a market for its carbon-dioxide byproduct. He pointed to Quad County Corn Processors in Galva, whose carbon dioxide emissions fell 41% since 2016. 

“Existing carbon capture methods aren’t utilized across the industry for some reason,” Hart said. 

Roe, the general manager of Little Sioux, noted production in some facilities is so large that carbon byproduct markets can’t offset carbon-dioxide emissions in a meaningful way. He added Little Sioux and 31 other ethanol plants have agreements with Summit Carbon Solutions to sequester its carbon byproduct via pipeline to western North Dakota. The offset in carbon emissions could provide Little Sioux’s ethanol at a premium in low-carbon fuel markets. 

Roe couldn’t estimate off-hand what percentage of CO2 the Summit pipeline would sequester.

Navigator CO2, which plans to run a carbon pipeline near Valero’s Albert City plant, estimated its project would have the potential to reduce CO2 emissions by up to 50%. In Albert City’s case, that would amount to 78,500 metric tons per year. 

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