Presidential Green Chemistry Challenge: 2012 Designing Greener Chemicals Award
Buckman International, Inc
Enzymes Reduce the Energy and Wood Fiber Required to Manufacture High-Quality Paper and Paperboard
Innovation and Benefits:Traditionally, making strong paper required costly wood pulp, energy-intensive treatment, or chemical additives. But that may change. Buckman's Maximyze® enzymes modify the cellulose in wood to increase the number of "fibrils" that bind the wood fibers to each other, thus making paper with improved strength and quality—without additional chemicals or energy. Buckman's process also allows papermaking with less wood fiber and higher percentages of recycled paper, enabling a single plant to save $1 million per year.
Summary of Technology: The paper and packaging industry is an important part of the U.S. economy, with product sales of $115 billion per year and employment of about 400,000 people. Previously, papermakers who needed to improve paper strength were limited to adding costly pulps, increasing mechanical treatment that expends significant energy, or using various chemical additives such as glyoxalated polyacrylamides and polyacrylamide copolymers.
Enzymes are extremely efficient tools for replacing conventional chemicals in papermaking applications. Buckman’s Maximyze® technology consists of new cellulase enzymes and combinations of enzymes derived from natural sources and produced by fermentation. These enzymes were not previously available commercially. Wood fibers treated with Maximyze® enzymes prior to refining (a mechanical treatment unique to papermaking) have substantially more fibrils that bind the wood fibers to each other. Maximyze® enzymes modify the cellulose polymers in the wood fiber so that the same level of refining produces much more surface area for hydrogen bonding, which is the basic source of strength in paper. As a result, Maximyze® treatment produces paper and paperboard with improved strength and quality.
Maximyze® improves strength so the weight of the paper product can be reduced or some of the wood fiber can be replaced with a mineral filler such as calcium carbonate. Maximyze® treatment makes it possible to use higher percentages of recycled paper. Maximyze® treatment uses less steam because the paper drains faster (increasing the production rate) and uses less electricity for refining. Maximyze® treatment is less toxic than current alternatives and is safer to handle, manufacture, transport, and use than current chemical treatments. These and other benefits are produced by Maximyze® treatment, a biotechnology that comes from renewable resources, is safe to use, and is itself completely recyclable.
The first commercial application began with the production of fine paper within the past two years. In 2011, a pulp and paper manufacturer in the Northwest began to add Maximyze® enzymes to the bleached pulp used to produce paperboard for food containers. This change increased machine speed by 20 feet per minute for a 2 percent increase in production. It also reduced the level of mechanical refining by 40 percent for a substantial savings in energy. Finally, it reduced the basis weight (density) of the paper by 3 pounds per 1,000 square feet without changing the specifications for quality. Overall, Maximyze® treatment reduced the amount of wood pulp required by at least 1 percent, which reduced the annual amount of wood needed to produce the food containers by at least 2,500 tons. Buckman estimates that using Maximyze® technology for this one machine can save wood pulp equivalent to 25,000 trees per year. Another large mill producing fine paper has used Buckman’s technology since January 2010 and saved over $1 million per year. Since introducing this new technology, Buckman has expanded it and is now applying it successfully in over 50 paper mills in the United States and beyond.
Podcast on the technology:(MP3, 1 MB, 1:05 seconds), Narrator: Dr. Richard Engler, US EPA.