Ethanol's Future Is In Corn Residue

Iowa Farm Scene

Ethanol made from corn stover will be produced at facility being built by DuPont in central Iowa.

Published on: December 4, 2012

DuPont came one step closer to commercializing advanced biofuels by breaking ground November 30 on its cellulosic ethanol manufacturing plant to be built at Nevada, Iowa. Completion is expected by mid-2014. The $200 million facility will be among the first and largest commercial-scale cellulosic biorefineries in the world.

The new plant will produce 30 million gallons annually of ethanol from cornstalks, leaves and other plant material. The crop residue will be baled and delivered to the plant after corn grain is harvested from the fields. "This stover will be gathered from cornfields within approximately a 30-mile radius of the plant," says Jim Collins, president of DuPont Industrial Biosciences. "It will be purchased from the farmers we contract with and will be stored at the plant."

NEW ENERGY CROP: Bales of corn crop residue mark the site where DuPont broke ground November 30 to begin building a cellulosic ethanol plant adjacent to Lincolnway Energys corn grain ethanol plant at Nevada, Iowa. Speaking at the ground-breaking ceremony (from left): Jan Koninckx, global business director for DuPont; Jim Collins, president, DuPont Industrial Biosciences; Iowa Gov. Terry Branstad and Iowa Lt. Gov. Kim Reynolds.
NEW ENERGY CROP: Bales of corn crop residue mark the site where DuPont broke ground November 30 to begin building a cellulosic ethanol plant adjacent to Lincolnway Energy's corn grain ethanol plant at Nevada, Iowa. Speaking at the ground-breaking ceremony (from left): Jan Koninckx, global business director for DuPont; Jim Collins, president, DuPont Industrial Biosciences; Iowa Gov. Terry Branstad and Iowa Lt. Gov. Kim Reynolds.

The development of cellulosic ethanol is crucial to help meet the amount of U.S. biofuel production called for in the federal Renewable Fuel Standard, a law which effectively limits the amount of ethanol made from corn grain to 18 billion gallons per year by 2020. The rest of the ethanol the U.S. produces per year will have to come from other sources, such as cellulose made from crop residue, grasses or wood biomass.

GOALS: The DuPont Cellulosic Ethanol Plant is to be built on this site, next to Lincolnway Energy, at Nevada, Iowa. Once fully operational, the DuPont facility will produce 30 million gallons of cellulosic ethanol per year, and its fully integrated end-to-end production system will be available to license globally.
GOALS: The DuPont Cellulosic Ethanol Plant is to be built on this site, next to Lincolnway Energy, at Nevada, Iowa. Once fully operational, the DuPont facility will produce 30 million gallons of cellulosic ethanol per year, and its fully integrated end-to-end production system will be available to license globally.

This is just the beginning -- the U.S. will need to build many more cellulosic ethanol plants
The RFS requires 13.2 billion gallons of corn-based ethanol to be blended into the U.S. gasoline supply in 2012. The total volume of renewable fuel required to be blended into the U.S. motor fuel supply is 36 billion gallons by 2022. "The U.S. will have to build 250 plants, each one twice the size as this one we are building in central Iowa, to supply the amount of cellulosic ethanol that will be eventually required by the Renewable Fuel Standard," notes Collins.

GOALS: The DuPont Cellulosic Ethanol Plant is to be built on this site, next to Lincolnway Energy, at Nevada, Iowa. Once fully operational, the DuPont facility will produce 30 million gallons of cellulosic ethanol per year, and its fully integrated end-to-end production system will be available to license globally.
GOALS: The DuPont Cellulosic Ethanol Plant is to be built on this site, next to Lincolnway Energy, at Nevada, Iowa. Once fully operational, the DuPont facility will produce 30 million gallons of cellulosic ethanol per year, and its fully integrated end-to-end production system will be available to license globally.

What is cellulosic ethanol? It is a motor fuel made from the biomass of a plant rather than from the grain, which is used to make conventional ethanol. Sources of feedstock to make cellulosic ethanol could include crop residue, wood, grass or other plant material.

Currently, two cellulosic ethanol manufacturing plants are under construction in Iowa that plan to use cornstalks, husks and corn leaves. One is the DuPont plant at Nevada in central Iowa; the other commercial cellulosic ethanol plant being built is a joint venture of Poet LLC and Dutch-based DSM Advanced Biofuels. It is under construction adjacent to Poet's corn grain ethanol plant at Emmetsburg in northwest Iowa. Poet spokesman Matt Merritt says construction of that cellulosic ethanol plant should be finished by the end of 2013, if everything stays on schedule. The Poet/DSM facility is expected to initially produce 20 million gallons of cellulosic ethanol annually, eventually increasing to 25 million gallons.

Making ethanol from crop residue instead of grain avoids food vs. fuel argument
The 30 million gallons per year of cellulosic ethanol to be produced by DuPont's new facility in central Iowa is more production capacity than the company's original estimates called for. "Data we've derived from our pilot plant facility in Tennessee has allowed us to further optimize our process and technology," says Collins.

The DuPont facility at Nevada in central Iowa is the first commercial-size facility the company is building and it will require a capital investment of about $7 per gallon of annual production capacity. "Nearly a decade ago, DuPont set out to develop innovative technology that would result in low capital and low-cost cellulosic ethanol production," says Collins. "We recognized that science-powered innovation was the catalyst to make cellulosic ethanol a commercial reality and to help reduce global dependence on fossil fuels."

DuPont officials say this plant is the next critical step in making advanced biofuels a reality
"By leveraging DuPont Pioneer's corn production expertise and designing an integrated technology platform, we've built an affordable and sustainable entry point into this new industry," says Collins. "We're committed to continued productivity gains to drive costs down even further for the coming generations of cellulosic ethanol plants -- facilities based on corn stover as well as other feedstocks," says Collins. "Of course, we didn't get to this point alone. We've built an incredible partnership with the state of Iowa, Iowa State University, entrepreneurial farmers and a whole host of partners around the country who share our vision of making renewable fuels a commercial reality."

At the ground-breaking ceremony November 30 for the DuPont plant, Collins was joined by Iowa Gov. Terry Branstad and other state and local officials to celebrate the beginning of construction of the new facility. The event was held at the construction site adjacent to Lincolnway Energy, a traditional ethanol plant that uses corn grain as feedstock. Lincolnway, a 50-million-gallon-per-year dry mill ethanol plant, is fired by coal and is locally owned by farmers and other central Iowa citizens who bought shares in it -- a total of around 900 people. Lincolnway Energy has been processing corn into fuel grade ethanol and distillers grains since the plant opened May 22, 2006.

"During my previous term as governor, we were excited to bring ethanol production to the state," Branstad told the crowd at the ground-breaking ceremony. "After many years of work by Iowa growers and technology companies like DuPont, Iowa now leads the country in renewable fuel production. This site at Nevada is the next critical step in our cellulosic ethanol journey. We look forward to bringing these advanced technologies online, creating local jobs and helping to deliver clean, sustainable energy."

What is the agricultural impact of harvesting this "new crop" for cellulosic ethanol production?
To supply the corn stover for its cellulosic ethanol plant, DuPont will contract with more than 500 local farmers to gather, store and deliver over 375,000 dry tons of stover per year into the Nevada facility. In addition to the estimated 60 full-time plant operations jobs, there will be over 150 people involved in the collection, stacking, transportation and storage of the stover feedstock seasonally during each harvest. The stover will be collected from an approximate 30 mile radius around the new facility and harvested off of 190,000 acres.

For many corn growers, crop residue management is a major challenge when maximizing their potential grain yield, points out Paul Schickler, president of DuPont Pioneer, a major seed company owned by DuPont and also involved in the project, working with farmers. Too much corn residue on the field interferes with planting, delays the establishment of corn stands in the spring, monopolizes nitrogen in the soil and often harbors damaging insect pests and pathogens. 

Thus, harvesting of corn residue has some agronomic benefits. "But not all of the corn stover from each field will be harvested for cellulosic ethanol," notes Schickler. "Some stover from the corn crop is left on the field to protect the soil from erosion."

For past three years DuPont has worked with local farmers in developing this project
For the past three years DuPont has been working with a number of farmers located in the vicinity of the Nevada plant in central Iowa, studying and testing the harvesting process in an effort to develop the best system to harvest, handle, transport and store the crop residue. Efficiency in harvesting and handling, while maintaining the quality of stover to use as a feedstock for ethanol production, are the goals.

"Many of us who have participated in the stover harvest program with DuPont are already seeing benefits of this alternative crop residue management strategy. That includes seeing positive effects on grain yields the following year after the crop residue is removed from our fields," says Jim Hill, a corn grower from nearby Ellsworth, Iowa. His corn stover, along with that of other farmers participating in the program, will be used to help supply DuPont's new biorefinery.  

Hill adds, "We are excited to work with DuPont to supply corn stover to this new biorefinery, to partner with them to discover new markets for the crops we produce and the coproducts that are produced, and to develop new crop production techniques based on the opportunity to manage crop residues through partial stover removal from the fields."

Collins says DuPont will further adapt its cellulosic ethanol technology to use additional types of feedstock. For example, the company is already processing switchgrass for cellulosic ethanol production in the testing facility it owns jointly with the University of Tennessee at Knoxville, Tenn.

What is the environmental impact of producing and using cellulosic ethanol?
The use of advanced biofuels can result in fewer greenhouse gas emissions, says Collins. An International Organization for Standardization (ISO) compliant, peer reviewed life cycle assessment of the planned DuPont biorefinery and supply chain indicates a potential greater than 100% reduction in greenhouse gas emissions compared to producing, refining and supplying gasoline. This significant greenhouse gas reduction is enabled by the use of cellulosic coproducts as a source of renewable energy.

The DuPont biorefinery coproduct is composed of lignin and corn syrup. Lignin is what's left after the crop residue is made into cellulosic ethanol. The leftover corn syrup is the portion of the syrup that isn't easily made into ethanol, says Collins. The lignin/syrup co-product is a material that can be burned to replace some of the coal that is used to fire an ethanol plant, he notes. The Lincolnway ethanol plant nearby is investigating the opportunity to burn lignin and syrup to help fire its boilers. The Lincolnway plant is currently burning 100% coal to make ethanol from corn grain. The lignin/syrup co-product can be mixed with coal.

DuPont cellulosic ethanol plant in central Iowa will use natural gas to fire its boilers
The City of Ames and the Iowa State University power plant are also interested in exploring the potential use of the renewable coproducts to replace portions of their coal fired operations. The DuPont cellulosic ethanol plant will use natural gas to fire its boilers. Since it will not be a coal fired plant, it won't be able to mix the lignin and syrup in and use it to help power itself.

"This cellulosic ethanol plant will indeed be a commercial plant, but it's also a demonstration plant which will show others what can be done to develop cellulosic ethanol production and marketing of the coproducts of the process on a wide scale in the U.S.," says Collins. "With that in mind, we decided to fire our cellulosic ethanol production plant with natural gas and to see what kind of a market we can develop locally to use the lignin and syrup that will come from cellulosic ethanol production."

DuPont plans to license the use of its fully integrated, end-to-end cellulosic ethanol production system to other companies who want to make cellulosic ethanol.

It will be a good fit to have a cellulosic ethanol plant next to a corn-fed ethanol plant
"We are excited to explore the various synergies between Lincolnway and DuPont that bring value to both companies," says Jeff Taylor, a farmer at nearby Gilbert, Iowa, and chairman of Lincolway's board of directors. "One area is the possibility of our corn-based ethanol plant using DuPont's cellulosic ethanol coproduct to replace at least some of our coal usage.

"We at Lincolnway strive to continually improve our operations and lessen our environmental impact," says Taylor. "Replacing our fossil fuels with this renewable cellulosic ethanol coproduct to generate heat and power makes great sense. The co-product will be generated right next door to us, and it would reduce our coal usage and reduce the transportation cost of shipping coal in railroad cars almost a thousand miles from coal sources in the western U.S. to our Lincolnway ethanol plant here in central Iowa."

Synergies can be developed between existing corn ethanol plants and next generation biofuel plants
"Our organization congratulates DuPont for achieving this milestone of breaking ground to build their cellulosic ethanol plant," says Monte Shaw, executive director of the Iowa Renewable Fuels Association. "Ground-breaking of DuPont's cellulosic ethanol plant is just the latest step forward for the next generation of biofuels. This is a major investment and a clear sign that a large sophisticated company, like DuPont, believes in the future of next generation biofuels."

It's also significant that DuPont is co-locating its cellulosic ethanol plant next to Lincolnway Energy, a locally-owned, traditional ethanol plant, says Shaw. "We at IRFA continue to believe that the synergies between existing corn ethanol plants and the next generation ethanol plants are clear and compelling. We're excited that Iowa remains on the forefront of ethanol innovation."

Iowa is the leader in renewable fuels production, says Shaw. Iowa has 13 biodiesel facilities with the capacity to produce 320 million gallons annually. In addition, Iowa has 41 ethanol refineries capable of producing nearly 3.7 billion gallons annually, with one traditional ethanol plant and two cellulosic ethanol facilities currently under construction. For information on the DuPont cellulosic ethanol project click on cellulosic biofuel. For information on the Poet/DSM cellulosic project to go POET-DSM Advanced Biofuels Joint Venture.