It’s an unfortunately all-too-common sight in early spring. Warming weather is suddenly interrupted by an unexpected freeze. In the cherry orchards of the northern United States, this could spell disaster for the new buds just poking out, killing the fruits before they even had a chance and leading to smaller harvests and economic losses for orchard owners.
But on these trees, instead of deadly ice crystals, the branches are snugly wrapped in a cloudy material that seems almost like clear peanut butter. The armor protecting these precious buds is called micro fibrillated cellulose, and it is created by breaking down cellulose from trees into its smallest components.
For Sappi, the global company that produced the micro fibrillated cellulose, this is just one application of their goal of using every part of the tree to support a myriad of industries.
For the U.S. Forest Service, who collaborated with Sappi along with Washington State University on developing the treatment, this is a perfect example of the value of forest products.
What happens to small diameter waste wood from forests? Research at the USDA Forest Service Forest Products Laboratory is finding new and innovative ways to transform these materials into nanocellulose products. From strengthening cement to extending shelf life of food, the Lab is turning forest byproducts into high-performance materials of tomorrow. (Forest Service video)
The produce of the forest
When one thinks of forest products, usually the first examples that come to mind are traditional products like lumber for construction, hardwoods for furniture or wood pulp for paper products. In fact, American paper and wood products companies produce millions of tons of goods annually, including lumber, panel products, paper and paperboard, adhesives, sealants and coatings.
The forest products industry accounts for approximately $288 billion annually of the U.S. economy, 4% of the total U.S. manufacturing output, employs about 950,000 people, with a payroll of approximately $50 billion annually, and is also among the top 10 manufacturing sector employers in 45 states.
But for the scientists and researchers at the Forest Products Laboratory of the Forest Service, wood is good for a lot more than just those uses. For more than a century, the Forest Service has been working with academia, private companies, industry and governmental agencies to develop innovative forest products that both bolster the nation’s economy and help keep forests healthy.
One of the most exciting growth areas is at the micro and nano-level. Despite their proverbial size, trees are made up of tiny molecules, with one of the most important being cellulose. Cellulose gives the cells of trees their structure, allowing them to reach their great height. That very structure also provides potential for a whole host of unexpected uses, from protecting cherry trees from frostbite to even helping prevent blowouts in oil and gas wells.
“Nanocellulose research is a key part of our work to support forest product markets,” said Kenneth Zwick, Forest Products Laboratory Assistant Director. “As pulp production declines in the US, we need to support the existing pulp market and develop new uses for pulpwood that keeps the wood demand balanced across all sizes of wood. Nanocellulose is a big part of the answer to both challenges.”
Micro molecules, macro impact
For Dr. Qi Wang, director of Research and Development for Sappi North America, forest products are a vital part of the global economy.
“Forest products have already been playing a significant role in global economy, ranging from construction, packaging, and printing,” Dr. Wang observed. “From Sappi’s perspective, we expect that forest products will play more prominent roles in the areas of packaging, textiles, and bio-based performance materials and chemicals.”
One of those bio-based performance materials is the fibrillated cellulose used to protect the cherries from a late frost. Operating under the brand name Valida, the fibrillated cellulose has been used on other fruits, like blueberries and apples, and Sappi is even looking at using it for seed coatings to protect the seeds from pathogens and environmental conditions until they can sprout.
One of the primary benefits of using cellulose is that it is both renewable and, as it is a natural part of all plants, non-toxic for the plants it is applied to. In fact, once the weather warms enough that frost is no longer a concern, the fibrillated cellulose can be harmlessly washed off the trees where it will naturally break down.
Innovations in forest products that advance economic development and protect forest and water health are the goal of collaborations between the Forest Products Laboratory and companies like Sappi.
“Over the years, we have closely collaborated with the Forest Products Laboratory in exploring applications of cellulose and beyond,” Dr. Wang said. “FPL provided both technical guidance through its scientists and funding for the project. We appreciate the support, which enabled us to expedite the development work in these applications.”
“This is a great application of nanocellulose technology because it will help save valuable fruit crops by lowering freezing temperatures by up to 4 degrees Celsius with a sustainable and biodegradable material, and it will provide a valuable new market for micro-fibrillated wood pulp,” Zwick said.
Finding the silver bullet for oil and gas production
On the other side of the country, amongst the purple and gold tailgating parties on the Louisiana State University campus, a solitary tower rises amongst the sea of purple and gold-clad fans. An oil and gas rig might be an unexpected sight on a college campus, but here too can be found the fruits of forest products.
This oil and gas rig is a platform for experiments. Professors and students test theories and technologies to improve the recovery rate of petroleum, reduce the amount of water and other resources required to produce the petroleum, and improve the environmental impact of the entire enterprise.
For Dr. Qinglin Wu, this is the platform to test his TigerBullets-Micro, materials made from trees to prevent the loss of drilling fluids within oil and gas wells during well construction. Drilling fluids, also called drilling muds, are used during well construction for production of petroleum. The drilling fluids circulate within the well bore, carrying rock debris to the surface, lubricating the drilling equipment and acting as a cooling agent.
However, if there are cracks or pores in the rock formation, these valuable drilling fluids can get trapped inside and lost, costing the oil and gas company time and money to replace them. Lost circulation costs the upstream oil and gas industry approximately $1 billion to $2 billion per year globally, solidifying its place as one of the single most expensive non-productive time problems faced during well construction.
That’s where Dr. Wu and his TigerBullets-Micro come in. Made of wood-based lignin containing cellulose nanofibrils, micro-sized wood fibers and other additives, the TigerBullets-Micro are mixed with the drilling fluids. The wood-based particles in the formulation are then forced into the formation in the rock layer, sealing cracks and pores in the rock and preventing the drilling fluids from getting trapped in them. Lignin-containing cellulose nanofibrils in the formulation can also help tune fluids to improve their stability and rock carrying capacity.
Dr. Wu received a grant from the Forest Service to help develop the cellulose nanofibrils and collaborated with the Forest Products Lab along with other partners to turn them into a commercial product. Already in use amongst many large oil and gas producers, Dr. Wu is developing newer version with dewatered cellulose nanomaterial cakes that are compounded with other ingredients and mixed with fluids prior to use, saving storage space and transportation costs.
“Using relatively low-cost nanocellulose to better seal well walls will help minimize environmental impacts of wells and reduce the costs of lost drilling fluids while building a valuable new market for pulp,” Zwick said.
The future is nano(cellulose)
Protecting fruit from frostbite and sealing oil and gas wells are just some of the possibilities that forest products from cellulose offer. From raw materials production to new applications for composite and paper products, to new generations of functional wood-based materials at the nanoscale, possibilities abound.
“Nanocellulose supports current pulp markets by making pulp and paper smoother and more impermeable to grease and oxygen, and thus a better substitute for plastic packaging,” Zwick said. “Nanocellulose is also a great product that can be made from available pulpwood in new, high efficiency biorefineries making fuels, chemicals and low-cost fibers.”
For the scientists and researchers at the Forest Products Laboratory, partnerships to create these exciting new products are proof of the value of their research and the importance of working with companies to bring these innovative forest products to the market. Benefitting forest health and the national economy.