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Breakthroughs Magazine

Special Report - Trash to Treasure

Woodpulp

Future Fill-ups May Use Paper Mill Waste

One man's trash is another man's treasure, or so goes the popular saying. At the U. S. Department of Energy's Pacific Northwest National Laboratory, waste materials such as byproducts from paper mills are becoming treasure thanks to a process that enables the cost-effective production of environmentally friendly fuels and other promising chemicals from low-value or waste biomass.

Paper mill sludge, an organic waste product that can be damaging to the environment, is cumbersome for mill operators to manage since it accumulates rapidly during operation. Current management options include drying and spreading the sludge on land, composting or transporting the material for deposit at landfills.

Research and technology demonstrations show that an important, multipurpose chemical called levulinic acid, which normally is produced from refined petroleum, can be produced from biomass such as paper mill sludge at a whopping one-tenth the cost of current manufacturing processes.

Building upon the levulinic acid production process developed by Biofine Corp., Pacific Northwest provides a patented catalysis process that upgrades the levulinic acid to produce methyltetrahydrofuran, or MTHF, for use in clean, alternative fuels and chemicals. This process doesn't create harmful pollutants or emit greenhouse gases and requires less energy for production.

The environmental benefits of combining these two processes are so promising and crosscutting to the chemical industry that it received one of five 1999 Presidential Green Chemistry Challenge Awards. "Green Chemistry" is the use of chemistry for pollution prevention and the design of chemical products and processes that reduce negative impacts to human health and the environment.

"This is an exciting technology emerging from DOE's investments in biomass conversion, a field where we are literally just touching the surface of the potential for using low-value and waste biomass material for valuable products," said Dennis Stiles, manager of Pacific Northwest's Agriculture and Food Processing Technology programs. "In the near future, we'll be expanding the technology to produce levulinic acid from other organic materials, such as straw left over from grain production, as well as producing a variety of other chemical products, such as solvents, herbicides and plastics, in addition to MTHF."

The levulinic acid conversion technology, which has been demonstrated in Biofine's pilot-scale facility in New York, is ready for commercialization. A search is underway to site a manufacturing plant in a major pulp and paper producing region, providing the capacity to produce levulinic acid and to upgrade this material to alternative fuels and other products, while reducing the cost of managing the waste sludge.

Green Chemistry Award

The "Oscars" of green chemistry were awarded by the Environmental Protection Agency in June, with the Pacific Northwest National Laboratory earning recognition as a contributor to one of the five 1999 Presidential Green Chemistry Challenge Awards. Pacific Northwest contributed to the winning technology that turns waste such as paper mill sludge and agricultural residues into a chemical building block that can be used to make environmentally friendly chemicals and alternative fuels.

EPA leads the Green Chemistry Program, which President Clinton announced in 1995. The program is designed to foster research, development and deployment of scientifically sound and cost-effective chemical technologies that prevent pollution. EPA receives more than 120 entries annually from organizations and institutions vying for the prestigious green chemistry awards. From the submittals, EPA selects a winner from two categories: academia and small business, and from three focus areas; alternative synthetic pathways, alternative reaction conditions and designing safer chemicals.

An independent panel selected by the American Chemical Society judges the nominated technologies. To earn the Presidential Award, the technologies must display scientific merit, offer benefits to human health or the environment and be widely applicable to chemical manufacturers, users or society at large.

Beyond French Fries

Potato

Researchers at Pacific Northwest National Laboratory have found a use for potatoes beyond french fries and hash browns. They have found a way for potato plants to produce cellulase, a valuable enzyme that can be used in detergent and textile manufacturing, food processing and fuel processing.

Normally, the tubers beneath the soil are harvested as food while the rest of a potato plant goes to waste. By inserting specific genes, however, the leaves of potato plants will produce cellulase without affecting the edible part of the plant or its use as a food crop. The same method can produce enzymes that can be used in medical diagnostics or as pharmaceuticals.

Working with plants in this way could bring additional profits for farmers who can harvest two products from a single crop—one for eating and the other for producing chemicals.

Another Helping of Potatoes

Beaker

Scientists at Pacific Northwest National Laboratory are experimenting with strains of yeast and bacteria that can feed on agricultural waste products and produce proteins for industrial biocatalysts and animal feeds.

"With molecular biology and advanced bioprocessing techniques, we can modify natural starch-degrading yeast strains to produce valuable foreign proteins directly from starch-rich byproducts," said Jianwei Gao, a senior research engineer. "In addition, this is an environmentally benign process since it only produces industrial biocatalysts in one stream. Its biomass byproduct, in the other stream, will be processed as high-quality cattle feeds, discharging no waste into the environment."

The use of these specialized strains of yeast may allow waste products from potato, wheat and corn processing plants to take the place of refined chemicals such as methanol, glucose and glycerol often used to feed protein production. The benefit of using yeast to produce proteins from waste products is twofold. With as much as 340,000 pounds of starch byproducts produced each day at a typical potato processing plant, this method can help alleviate a waste problem. It also could reduce the cost of producing proteins because it would eliminate the need for refined chemicals.

Nuclear Waste Delivering a Dose of Hope

Nuclear waste and cancer may be among society's most serious concerns, but researchers have found a way to use one to treat the other.

Yttrium

An innovative cancer therapy relies on a derivative of waste from nuclear weapons production. Through a process patented by Pacific Northwest National Laboratory, an ultra-pure form of the medical isotope yttrium-90, used to treat a variety of cancers, is being extracted from the weapons production byproduct strontium-90.

Final trial results are expected this year from Switzerland's University Hospital in Basel, where brain cancer patients are receiving the therapy.

Patients receive an injection of yttrium-90 linked to specially engineered peptides that seek out brain tumor cells. Once inside the tumor, the peptides bind to the tumor cells, delivering a high dose of radiation to cancerous cells while minimizing impact to surrounding healthy tissue. The treatment causes few side effects and can be administered on an outpatient basis.

Pacific Northwest is in the final phases of commercializing the production, distribution and sales of yttrium-90. A private company, New England Nuclear Life Sciences Products Inc., of Boston, Mass., is leasing 40 curies of strontium-90 from Pacific Northwest each week and has licensed the patented process for "milking" yttrium-90 from the isotope.

New Tobacco Products Good for Health

Forget cigarettes! Scientists at Pacific Northwest National Laboratory have found a use for tobacco plants that doctors actually may condone. They have genetically modified tobacco plants to produce human blood proteins and tissue growth factors, which may lead to safer and more cost-effective medical treatments.

Tobacco Leaf

Using plants to produce human blood proteins is better than conventional processes that use human blood, animal cell cultures or whole animals for several reasons. Plant-produced proteins eliminate the possibility of transmitting blood-borne pathogens such as HIV or hepatitis, are substantially less expensive and provide a stable production source with a higher yield.

Scientists have used tobacco plants to produce blood coagulation Factor VIII, which is critical in treating hemophiliacs. The same approach also has produced thrombin and Factor XIII—clotting enzymes that help wounds heal and could be alternatives to sutures and other surgical sealants.

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