Nevada plant considering stover harvesting
By KRISS NELSON
NEVADA – DuPont Cellulosic Ethanol announced earlier this year plans to break ground on a commercial biorefinery in Nevada.
A Central Iowa corn stover harvest meeting was held Aug. 13 at the Story County Extension office in Nevada in order for DCE and Iowa State University Extension to present new findings of ongoing research into harvesting corn stover. An estimated 100 people attended the meeting.
Dennis Penland, business development manager for DuPont Industrial Biosciences said that he hopes groundbreaking for what has been named “DuPont Project Blackhawk” happens later this year and after that it should take 12 to 18 months from the beginning of construction to start up of the 25 million gallons a year of ethanol from corn stover plant.
Penland estimates there will be enough corn stover to harvest within a 30-mile radius surrounding Nevada. Stover is all of the above ground plant material other than the grain.
Reasons for choosing the Nevada location, Penland said include producer interest and support, the existing ethanol plant, Lincolnway Energy, which the new facility will be a neighbor, the heavy concentration of corn produced in the area and having ISU in the area, which has been helpful in research and getting the project going.
According to Penland, their business mission is, “to design and implement a cost-effective and scalable feedstock supply chain providing consistency of volume and quality for a commercial cellulosic biorefinery.” This feedstock sourcing is estimated to generate $21 million a year in local revenue.
Rather than having the producer harvest and transport his own stover, DCE plans to use a third party to harvest the stover in a two-pass method of windrowing and baling.
That contractor will pick up and stack the bales and transport them to the biorefinery.
Penland said DCE is still learning the cost values of a stover harvest. The best estimate is $24 per acre needed for nutrient replacement; then revenues of a $30 an acre stover payment; an estimated $25 an acre yield gain and an also estimated of $20 an acre gained due to agronomic efficiencies of reduced tillage passes, fall stalk chopping, the use of chemicals to break down material, faster and earlier planting.
The estimated revenue of $75 per acre, minus the cost of about $24 in nutrient replacement, Penland said, will give corn stover harvest value on a corn-on-corn field of about $50 an acre.
In order to make that, however, there has to be a high quality product coming out of the field. Dr. Matt Darr, agricultural and biosystems engineering assistant professor at ISU, presented information regarding harvest logistics and stover quality.
According to Darr, the harvest index for corn stover is 50:50, which means that for every ton of grain per acre, there is also a ton of stover per acre.
The 25 million-gallon cellulosic ethanol plant, he said, will require 335,000 tons of biomass a year, which is approximately 700,000 large bales per year.
It is also estimated, Darr said, the new plant will generate 40 new jobs.
“There are many economic benefits to these sorts of enterprises,” said Darr.
Biorefineries, Darr said, desire a uniform feedstock with a low ash (or dirt) content and a low moisture content.
With a normal harvest, the moisture content, he said will usually meet the less than 20 percent moisture requirement.
Large square bales are the most efficient to use for industrial biomass production, Darr said, especially when compared to large round bales.
“There is efficiency gained by moving square units over round bales,” he said.
But before the baling can begin, Darr advised that when stover is being cut, it’s important to ensure the shredders do not touch the ground and the rakes don’t bring any more dirt in to the biomass.
“You don’t want to see dirt behind the windrower, that would be an erosion issue and means dirt has been raked into the windrow,” said Darr.
There are many different brands of windrowers, rakes and balers available for harvesting corn stover as well as different bale collection systems including bale wagons that drive, pick up and collect and are capable of keeping pace with two balers.
The wagons get the bales moved efficiently to the edge of the field, he said which provides a disconnect of the baling process to the producer so they are able to continue with any fall nutrient applications and tillage.
Transporting biomass, Darr said, is typically done with semi-trucks and flatbed trailers, with bale squeezers capable of moving six to nine bales at a time and load a semi in 6 to 8 minutes.
“This is a brand new market,” said Chad Hart, a grain markets specialist for ISU.
Contracts, Hart said, are better than handshakes and will help outline the risk-return tradeoff between buyers and sellers and will often address major benefits and challenges of the trade.
Hart explained that an ISU survey indicates there is “a lot of knowledge” of corn ethanol market and not so much the cellulosic market, which is good, Hart said, leaving a lot of room for educating.
The survey showed there is an interest in supplying biomass, but also concerns on residue management, nutrient loss and soil erosion.
“Nutrient loss was a big concern and there is a lot of variability with that,” Hart said.
Distance to market was another concern, and with DCE they are handling that part and with the other cellulosic plant operated by POET in Emmetsburg, it is up to the producer with a price help.
On ISU’s Ag Decision Maker website, there is a spreadsheet available, “Estimating a Value for Corn Stover.”
This spreadsheet, Hart said, helps with cost and compares harvesting corn stover for cellulosic uses to feeding the bale to livestock.
Hart said producers must determined if stover removal has been addressed in the lease agreement as to if the stover belongs to the producer or to the land owner; yield impact of stover removal and the possibility of added compaction to the land.
“How will our corn respond to stover removal? That is important research to watch,” Hart said. “The beauty of corn stover is we are still producing grain, so it is always available.”