Thesis
Hot water extraction of anaerobic digested dairy fiber for wood plastic composites manufacturing
Washington State University
Master of Science (MS), Washington State University
05/2016
Handle:
https://hdl.handle.net/2376/101897
Abstract
Dairy farmers worldwide have been facing the difficulty of managing or disposing of often large volumes of manure produced, since it can pollute water systems and the air, as well as be a problem to humans and animals due to odor and pathogen content. A proposed solution for this issue is to use anaerobic digestion (AD) to treat the manure and produce biogas. During this process most pathogens, odor and greenhouse gas components are removed. A byproduct of AD is un-digested, recalcitrant fibrous solids. This fiber has yet to find mature high-value markets, despite some of its intriguing properties. One potential use involves its mix with high density polyethylene (HDPE) for wood plastic composites (WPC) production. This type of composite is currently used for decking, automobile components and other applications. When used as a decking material, WPCs must offer properties suitable for use within high moisture content environments. In this study AD fiber was treated via hot water extraction (HWE) for 60 minutes to reduce its hydrophilicity by removing hemicelluloses and promoting lignin migration to the cell wall surface. Five different HWE temperatures were tested and resulting aqueous and solid phases were characterized. One HWE temperature (160oC) was chosen and its resulting fiber was used for production of WPC via extrusion. Mechanical properties and water affinity of composites produced using AD fiber were compared to those with pine flour. Also, the influence of treating AD fiber via HWE for composites production was evaluated. Increase on mechanical strength (by 36%) and stiffness (by 30%) and reduction on strain at break (by 15%) were noticed on WPC after treating the fiber. Furthermore, water uptake and thickness swelling were reduced by 39% and 36% after immersion in water for 98 days when using treated fiber. The diffusion constant when using HWE-treated AD fiber was reduced by 64%. These results showed that HWE of AD fiber is an effective method for enhancing mechanical properties of its composites and reducing its water affinity and swelling. However, additional work is needed to improve the morphology of the composites.
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Details
- Title
- Hot water extraction of anaerobic digested dairy fiber for wood plastic composites manufacturing
- Creators
- Gabriela Pereira Ferraz
- Contributors
- Manuel Garcia-Perez (Chair)Karl Richard Englund (Committee Member) - Washington State University, Composite Materials and Engineering CenterClaudio Osvaldo Stockle (Committee Member) - Washington State University, Biological Systems Engineering, Department of
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Number of pages
- 68
- Identifiers
- 99900525017401842
- Language
- English
- Resource Type
- Thesis