DOE Project Uses Bacteria to Make Biodegradable Plastic-Wood Composites from Waste

January 26, 2011

Bacteria-made wood cells, enlarged 1000 times by a microscope.

The dark board (left) was made entirely from waste using a low-cost, energy-efficient method developed by scientists from INL, the University of California—Davis, and Washington State University. (Image courtesy of Idaho National Laboratory)

A research project funded by DOE's Industrial Technologies Program has developed a low-cost, energy-efficient process to make eco-friendly wood-plastic composites from waste streams. Partners on the project include Idaho National Laboratory, Washington State University, University of California-Davis, Glatfelter Paper Corporation, ECO:LOGIC Engineering, and Strandex Corporation. The novel process feeds industrial or municipal waste streams to harmless, naturally occurring bacteria, which convert the waste into polymers called polyhydroxyalkanoates (PHA). Once the bacteria produce and store enough plastic inside them, they are dried, mixed with sawdust, and molded directly into wood-plastic composite boards that have about the same mechanical properties as boards made with petroleum-based plastics—yet are biodegradable. Costs are 80% lower than earlier bacterial PHA processes that fed the bacteria on refined sugars then carefully separated the bacterial cells from the produced plastic. The new processing route eliminates the use of petroleum-based plastics and avoids the energy use and emissions associated with fertilizers, agricultural operations, and separation processes. It has successfully used bacteria and waste from a brewery in California, a municipal wastewater treatment plant in Idaho, and a pulp-and-paper mill in Ohio. The research team is currently in the process of finding sponsors for a larger test run to help commercialize the process. (Based on an article by Sandra Chung, Idaho National Laboratory)