Cellulosic ethanol production using corn stover as the feedstock is going commercial, but over the short term it won’t make any more grain corn available for human or livestock use, according to Kyle Althoff.
It will however, provide additional returns to farmers in the form of stover payments and potential agronomic benefits.
“We don’t see going five to 10 years down the road that we’re going to reduce the corn ethanol that’s out there,” Althoff, director of feedstock development with DuPont Danisco Cellulosic Ethanol LLC (DDCE), said in an interview here Feb. 24. “It’s going to be supplemental to the amount of ethanol that we bring into production.”
DDCE is a joint venture between DuPont and Danisco’s Genencor division formed in 2008 with the goal of commercializing cellulosic ethanol production. (In January DuPont entered into an agreement to buy Danisco, a global enzyme and specialty foods ingredient company for $5.8 billion.)
DDCE opened a pilot plant in Vonore, Tennessee last year, producing 250,000 gallons (U. S.) of ethanol, Althoff told reporters attending a meeting hosted by Pioneer Hi-Bred at its world headquarters.
A commercial cellulosic plant will be built next year, probably in Iowa, and it will start pumping out ethanol by late 2013 or early 2014, he said.
DDCE will license its cellulosic technology to others, including farmer-owned groups, who will build and operate the plants.
The goal is to make ethanol from corn stover, as well as other plant materials such as switchgrass and sorghum for around $1.70 a U.S. gallon, which is similar to the cost of producing petroleum fuel, Althoff said.
Even though cellulosic ethanol will be cheaper to make than ethanol from corn, it’s no threat to corn ethanol because the American government has mandated 16 billion gallons of biofuel must come from cellulosic sources by 2022, Althoff said.
The American government also requires that cellulosic ethanol reduce greenhouse gas emissions by at least 60 per cent. According to Althoff DDCE’s technology cuts them 110 per cent when switchgrass is the feedstuff and 130 per cent with corn stover.
DDCE expects corn stover ethanol plants will be built close to existing grain corn plants. The new plants can then tap into existing infrastructure, plus help fuel the corn plants with lignin, the high-energy byproduct from cellulosic ethanol production.
The farmers within a 35-to 40-mile radius that already deliver grain corn for ethanol production will have the option to deliver their stover too.
“It’s going to be localized markets to supply the stover that’s going to be needed for each facility,” Althoff said.
Surplus lignin might even replace some coal in coal-fired electrical generation plants, he said.
Depending on grain corn prices, stover can earn farmers $35 to $70 a ton, Althoff said. He expects baled, dry stover delivered to a cellulosic ethanol plant will earn farmers $50 to $70 a ton.
Some farmers will invest in harvesting their own stover. Windrowing and then baling collects the most stover per acre. Others will hire the work done.
A certain amount of stover needs to remain in the field, not only to replenish soil nutrients and organic matter, but also to mitigate soil erosion and conserve soil moisture, Althoff said.
“We’re focused on making sure that we’re being a good partner out there for the farmers in maintaining the quality of the land from an agronomic standpoint,” he said.
For many corn belt farmers, too much stover is becoming a problem. It requires more tillage to prepare a proper seedbed. Tillage costs money and releases greenhouse gases.
“That’s where we potentially see some of the biggest gains for farmers,” Althoff said. “There has been some work that shows the gain (by removing some stover) can be from zero to 10 per cent. If you’re talking 200-bushel-an-acre corn a 10 per cent yield bump is 20 bushels an acre.”
“That’s a significant value back to the grower to capture, but it varies with soil types, varieties with varieties and weather conditions. It’s something we’re going to do more research on to understand what realistically a producer can expect from removing stover,” Althoff said
The higher the corn yield, the more stover there is. A field that yields 250 bushels an acre will produce about six tons (dry) of stover, Althoff said.
Corn stover will likely be the feedstuff of choice in the corn belt, but in areas where it’s less efficient to grow corn, such as the southern and southeastern U.S., switchgrass will be one of the main crop options,” Althoff said.
The first step to making cellulosic ethanol is to break the incoming feedstuff up then feed it into a saccharifier. DDCE produces its own proprietary enzymes to break the product down into simple sugars before the fermenting process. DDCE’s process keeps capital costs low by allowing it to put the different sugars into one vessel. [email protected]
“Wedon’tseegoing fiveto10yearsdown theroadthatwe’re goingtoreduce thecornethanol that’soutthere.”
– KYLE ALTHOFF