The AltEn sign had been taken down by January 2022, but the cleanup at the plant, which used contaminated seed corn to make corn-based ethanol, continues. (Paul Hammel/Nebraska Examiner)
LINCOLN — A massive concrete plant in Louisville, Nebraska, has won state approval to burn “biomass,” including some treated seeds, in its kilns as a cleaner alternative to natural gas and other fossil fuels.
But a spokesman for Ash Grove Cement made it clear Wednesday that the leftover, pesticide-coated seed corn — known as “wet cake” — that was used at the now-closed AltEn ethanol plant near Mead won’t be among the biomass to be burned.
“Ash Grove can confirm that it has not used seed from the closed ethanol plant in Mead, Nebraska, as part of the fuel mix at its Louisville plant and has no plans to do so in the future,” said spokesman Brian Dryfhout for the company, headquartered in Dublin, Ireland.
In March, the Nebraska Department of Environment and Energy approved an amendment to Ash Grove’s air quality permit to permit the use of biomass in kilns used to produce cement, according to state records.
‘Clean cellulosic biomass’
That sparked some speculation that the biomass might include some of the thousands of tons of contaminated, waste seed corn stockpiled at AltEn.
Public meeting Thursday
What: Scientists from the University of Nebraska Medical Center and the University of Nebraska-Lincoln will discuss preliminary results of environmental studies conducted near the AltEn plant.
When: 7 p.m., June 16
Where: Mead Fire Hall
But an NDEE official confirmed that while treated seed that meets the definition of “clean cellulosic biomass” can be used under the new permit, “wet cake” — or spent grain left over after producing ethanol — cannot.
The wet cake had piled up at the Mead plant after state regulators halted its use as a soil conditioner and after local landfills stopped taking it. Piles of the seed corn covered 16 acres at one point. This spring, the piles were covered with a plaster-like coating to mitigate odors while a permanent solution is found.
Incineration is one of the options being explored for finally disposing of the wet cake, though no decision has been made yet about “effective disposal options,” said Don Gunster of NewFields, one of the companies involved in the AltEn Facility Response Group working on the cleanup at the plant.
The AltEn plant has drawn national environmental attention since it was revealed a year ago that the plant had, for years, been using expired seed corn, coated in pesticides, to produce ethanol. Typically, ethanol is made using field corn, like that fed to livestock. Seed corn, meanwhile, is toxic.
AltEn was ordered closed by the NDEE in February 2021 after the plant’s owners ignored several state directives to dispose of the spent grain and repair wastewater lagoons at the facility that had become filled past regulatory limits.
The plant had been the subject of several complaints by nearby residents about foul odors since it was restarted in 2015.
Alternative to coal, coke, natural gas
According to NDEE records, Ash Grove conducted test burns using soybeans as biomass from August 2020 to February 2021.
The company, according to the state records, had been evaluating “options” to utilizing fossil fuels, such as coal, coke and natural gas, to heat its kilns.
“We have identified biomass as an effective, and readily available, alternative,” Ash Grove reported.
The company added that the trials were overall a “success” and that using biomass resulted in similar or lower emissions. A permit to allow the use of biomass was approved in March after public notice and a public comment period.
An Ash Grove spokesman did not say Wednesday what kind of biomass is being utilized.
Leftover wood from construction projects, as well as sawdust and wood pellets, have been used in kilns to produce cement and dry lumber, according to a recent article in Biomass magazine.
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