DuPont's Commercial-Scale Cellulosic Ethanol Facility, Nevada, Iowa, United States of America

Dupoint cellulosic ethanol facility

DuPont's new commercial-scale cellulosic ethanol facility under construction in Nevada, Iowa, US, is set for completion in 2015. Production capacity of 30 million gallons (113l) of fuel-grade cellulosic ethanol a year, making it one of the biggest facilities of its kind in the country.

The overall investment for the project is an estimated $225m. It is being met through grants from the Iowa Power Fund and the Grow Iowa Values Fund.

Groundbreaking ceremony for the facility was held in November 2012. The project is being implemented based on the results and experiences gained from the fully-integrated cellulosic ethanol demonstration plant in Vonore, Tennessee, which DuPont commissioned in January 2010 in collaboration with the University of Tennessee and Genera Energy.

Location of Dupont's new cellulosic ethanol facility in Nevada

The plant is being built adjacent to the existing coal-fired dry mill ethanol plant of Lincolnway Energy. The site was selected in 2011 based on its close proximity to the Pacific Class 1 Rail Road, the Interstate 35 and the US Highway 30, and the availability of feedstock.

"The project is being implemented based on the results and experiences gained from the fully-integrated cellulosic ethanol demonstration plant in Vonore, Tennessee."

The project is expected to create 85 permanent jobs and 1,000 construction jobs while 150 people will be involved in the collection, stacking, transportation and storage of seasonal feedstock for the plant when it comes online.

Feedstock for DuPont's Nevada biorefinery

The new cellulosic bioethanol refinery will require approximately 375,000t of corn stover a year, harvested from approximately 190,000 acres. Up to 500 local farmers will be contracted to supply the stover from within a 30-mile radius of the project site.

DuPont has signed a memorandum of understanding (MoU) with the USDA's Natural Resource Conservation Service (NRCS) to promote sustainable harvesting of feedstock for the plant. Under this agreement, DuPont will primarily provide conservation planning assistance to the feedstock suppliers, develop sustainable harvesting practices and protect the soil from erosion.

DuPont's cellulosic ethanol production process

The same conversion process proven at the pilot demonstration facility will be implemented at the commercial facility. The technology integrates a five-stage process for the conversion of stover into ethanol.

The first stage involves milling and pre-processing of the biomass to reduce particle size of the raw materials. The second stage involves pretreatment of the biomass substrate using a proprietary mild alkaline process to separate lignin and hemicellulose from the cellulose.

Arkema, a global producer of chemicals and advanced materials, opened a new methyl acrylate production plant in July 2014.

The third stage involves saccharification or enzyme hydrolysis, to convert cellulosic materials to fermentable sugars using the company's proprietary Accellerase enzymes.

The fourth stage involves fermentation of the sugars to produce cellulosic ethanol using a proprietary biocatalyst based on Zymomonas mobilis bacterium. In the final stage, ethanol is separated from the lignin residues, unreacted cellulose, hemicellulose, ash, enzymes and microorganisms.

Key players involved

Fagen is the engineering, procurement and construction (EPC) contractor for the project, while the front-end engineering and design (FEED) study as well as the procurement were performed by KBR.

Murex was contracted to market the cellulosic ethanol produced from the plant in September 2014.

Procter & Gamble will purchase a portion of the cellulosic ethanol from the plant, to blend it with its proprietary Tide cold water laundry detergent.

NRI Energy Technology