ORONO, Maine – The University of Maine’s Forest Bioproducts Research Institute is building a pilot-scale plant for manufacturing cellulose nanofibrils (CNF), a wood-based reinforcing material that is increasingly of interest to researchers worldwide looking for super-strong materials that could replicate synthetic plastics.
The pilot plant, which is being funded by a $1.5 million grant from the U.S. Forest Service, will be the only one of its kind in the nation, and will serve as a source of the material for those who want to explore the uses of cellulose nanofibrils (CNF). Currently, researchers and industrial companies who want to buy the material purchase it from sources in Japan and Germany.
“With development of new natural and functional nanomaterials, UMaine will be recognized as an innovator in novel cellulose nanofibril processing,” said FBRI Director and UMaine Professor of Chemical and Biological Engineering Hemant Pendse, one of the researchers involved with the project. “UMaine will have the ability to process cellulose nanofibrils in ways that open up new markets and applications for cellulose nanocomposites.”
UMaine is involved in the project with a consortium of six other universities and the Forest Products Laboratory (FPL). Last April, UMaine and FPL began a research collaboration on the conversion of wood components into novel nanomaterials, the incorporation of an array of nanomaterials into forest products to increase their functionality, durability, and end use performance, and the development of new generations of high-performance wood-based materials. UMaine will be the sole supplier of CNF to researchers from other universities in the consortium, which include the Georgia Institute of Technology, North Carolina State University, Oregon State University, Pennsylvania State University, Purdue University and University of Tennessee.
Sean Ireland, of pulp and paper industry group TAPPI and Verso Paper in Bucksport, is also involved in the consortium.
Applications for the CNF material include automobile components, paint and coating additives, and water filters. Development and commercialization have been hampered by the lack of availability of CNF material in sufficient quantities to conduct meaningful technology demonstrations. This project will address this need by scaling up the mechanical laboratory preparation method to a pilot-scale operation.
The grant will fund the purchase of an ultrafine grinder, a piece of equipment which breaks down cellulose-based pulp into a water-based slurry, and a pilot-scale spray dryer, which uses gases to dry the material. The ultrafine grinder will be able to produce about 1,000 pounds of material a day in slurry form. The drying process will produce approximately 1-2 pounds of dry material per day.
Both pieces of equipment are expected to be in place next spring in Jenness Hall, the home of UMaine’s Process Development Center and FBRI. UMaine already has an operational bench-scale ultrafine grinder.
Cellulose nanofibril material is valued because of its strength – a strand of it is as strong as a synthetic fiber such as Kevlar. It takes on different properties depending on how it is dried. When a sample of the CNF slurry is dried with heat, the material becomes hard and strong, and can be cut into different shapes and sizes. When freeze-dried, the material is super-absorbent and insulating.
The cellulose nanofibrils are about 1,000 times smaller than paper fibers. The material can be made from any source that contains cellulose, such as wood, grasses, and corn or wheat straw.
“If you can make products from nanofibrillated cellulose that normally use plastic, you can reduce the use of petroleum,” said Doug Bousfield, UMaine professor of chemical and biological engineering and director of the Paper Surface Science Program who is also collaborating on the project and has already incorporated cellulose nanofibrils in paper coatings. “It makes sense for Maine, and that’s what’s exciting about it. There is a long list of ideas but it takes resources to try them out. What this project does is put the equipment in place to generate a lot of raw material with which people can experiment.”
UMaine already produces some cellulose nanofibrils via both mechanical means and chemical means, the latter of which produces cellulose nanocrystals.
Doug Gardner, a UMaine professor of wood science and technology and the head of the Nanocomposites Research Group who is also a collaborator, said although the mechanisms are not yet in place for researchers and companies to order the material, there has already been unofficial interest from private industry. The material would not be free for those who want to order it, but UMaine would offer it at a reasonable price.
Other UMaine researchers involved include FBRI Associate Director Mike Bilodeau, who is the principal investigator on the project, and UMaine Associate Professor of Chemical and Biological Engineering David Neivandt, who is also the director of product development for UMaine’s Pulp and Paper Process Development Center.