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Title: Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy- Efficient Wood-Plastic Composites

In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. We have demonstrated that biopolymers (polyhydroxyalkanoates, PHA) can be successfully produced from wood pulping waste streams and that viable wood fiber reinforced thermoplastic composite products can be produced from these materials. The results show that microbial polyester (PHB in this study) can be extruded together with wastewater-derived cell mass and wood flour into deck products having performance properties comparable to existing commercial HDPE/WF composite products. This study has thus proven the underlying concept that the microbial polyesters produced from waste effluents can be used to make cost-effective and energy-efficient wood-plastic composites. The cost of purified microbial polyesters is about 5-20 times that of HDPE depending on the cost of crude oil, due to high purification (40%), carbon substrate (40%) and sterilized fermentation (20%) costsmore » for the PHB. Hence, the ability to produce competitive and functional composites with unpurified PHA-biomass mixtures from waste carbon sources in unsterile systems—without cell debris removal—is a significant step forward in producing competitive value-added structural composites from forest products residuals using a biorefinery approach. As demonstrated in the energy and waste analysis for the project, significant energy savings and waste reductions can also be realized using this approach. We recommend that the next step for development of useful products using this technology is to scale the technology from the 700-L pilot reactor to a small-scale production facility, with dedicated operation staff and engineering controls. In addition, we recommend that a market study be conducted as well as further product development for construction products that will utilize the unique properties of this bio-based material.« less
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Publication Date:
OSTI Identifier:
Report Number(s):
TRN: US201010%%43
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Idaho National Engineering Laboratory (United States); Idaho National Laboratory (INL), Idaho Falls, ID
Sponsoring Org:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy (EE)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; CARBON; CARBON SOURCES; CONSTRUCTION; ENERGY ACCOUNTING; FERMENTATION; FIBERS; FORESTS; FUNCTIONALS; MARKET; MIXTURES; PETROLEUM; POLYESTERS; PURIFICATION; REMOVAL; SUBSTRATES; THERMOPLASTICS; WASTES; WOOD; WOOD-PLASTIC COMPOSITES biorefinery; construction materials; forest products; foul condensate; polyhydroxyalkanoate; pulp mill effluents; waste activated sludge; wood fiber reinforced thermoplastic composite