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Life Cycle Impact Assessment of flax fibre for the reinforcement of composites. Nilmini Dissanayake, John Summerscales, Stephen Grove and Miggy Singh. Content. Goal and scope Life Cycle Assessment (LCA) System boundaries Life Cycle Inventory Analysis ( LCI )
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Life Cycle Impact Assessment of flax fibre for the reinforcement of composites Nilmini Dissanayake,John Summerscales, Stephen Grove and Miggy Singh
Content • Goal and scope • Life Cycle Assessment (LCA) • System boundaries • Life Cycle Inventory Analysis (LCI) • Environmental Impact Classification Factors (EICF) • Methodology • Life Cycle Impact Assessment (LCIA) • Discussion • Conclusion • Future work
Goal and scope • To determine the sustainability of natural fibres as reinforcement in polymer matrix composites (referenced to glass fibres) • Cradle-to-factory gate • Agricultural operations (from ploughing to harvest) • Fibre extraction operations (retting and decortication) • Fibre preparation operations (hackling and carding) • Fibre processing operations (spinning or finishing) • The functional unit : “one tonne of flax fibres for reinforcement in polymer matrix composites” (assumes Ef=42 GPa equal specific modulus)
Flax • flax fibre chosen as it is the most agro-chemical intensive bast fibre used as reinforcement • other bast fibres could be “greener”provided yield/hectare andperformance are satisfactory
Life Cycle Assessment (LCA) Interpretation Goal and Scope Definition Inventory Analysis Impact Assessment
System Boundaries Seed, Fertiliser, Pesticides, Diesel Machinery Crop Production Dry, green flax stems Water Retting Diesel, Machinery, Water Dry, retted flax Atmospheric Emissions Emissions into water Co-products and waste Scutching Electricity Scutched long fibre Hackling Electricity SLIVER Wet Spinning Electricity, Water YARN
Environmental Impact Classification Factors Global Warming Potential (GWP) Human Toxicity Potential (HTP) Acidification Potential (AP) Eutrophication Potential (EP) Aquatic Toxicity Potential (ATP) Non-Renewable/Abiotic Resource Depletion Potential (NRADP) Ozone Depletion Potential (ODP) Photochemical Oxidants Creation Potential (POCP)
Methodology In the impact assessment interpretation of the LCI data, Environmental impact potential, Where: Bjx = burden (release of emission j or consumption of resource j per functional unit) ec1= characterisation factor for emission j continues …
Non-renewable/abiotic resource depletion potential is calculated using : Where: Bj = burden (consumption of resource j per functional unit) ec1= estimated total world reserves of resource j. As defined by Adisa Azapagic et al (2003, 2004) in Polymers, the Environment and Sustainable Development and Sustainable Development in practice –case studies for engineers and scientists
Life Cycle Impact Assessment (LCIA)- initial results continues …
Discussion • Agricultural activities dominate all environmental impact categories • 39% of GWP 92% of HTP 94% of AP and EP • Production of agro-chemicals is not included • (but they do have high embodied energy) • No significant contribution identified for • Ozone Depletion Potential (ODP) • Photochemical Oxidation Creation Potential (POCP) • from growth and processing of flax fibres
Discussion.. • spinning uses 39% of total GWP, and 67% of NRADP • the embodied energies for flax (no-till agriculture): • 59 GJ/tonne for sliver (55 GJ/tonne for glass mat) • 89 GJ/tonne for yarn (26 GJ/tonne for continuous glass) • if flax sliver, not yarn, used as reinforcement, then magnitude of environmental impacts reduced by 40% for GWP 44% for HTP, and 46% for NRADP
Burdens from … • no till < conservation agriculture<mouldboard plough • organic fertiliser <agro-chemicals • biological control of pests<pesticides • water-<dew- <bio-retting • sliver<spun yarn
Future Work • improve the LCIA by considering both direct and indirect energy sources • carry out an LCIA for glass fibre production • study the fibre orientation distribution factor for flax fibre yarn and sliver • complete the LCA for production of both flax and glass fibre
Conclusion • “green” claim for flax fibres as reinforcement in composites is not justified when judged against embodied energy of glass fibres • conservation agriculture and organic fertiliser will improve environmental credentials of flax • environmental impacts could be reduced by eliminating the spinning operation
References • Environmental Management - Life Cycle Assessment - principles and frameworks, ISO 14040:2006. 2006. • Environment Management - Life Cycle Assessment - requirements and guidelines, ISO 14044:2006. 2006. • Turner, J.A., Linseed Law: A handbook for growers and advisers. 1987: BASF (UK) Limited, Hadleigh. • West, T.O. and A.C. McBride, The contribution of agricultural lime to carbon dioxide emissions in the United States: dissolution, transport, and net emissions. Agriculture, Ecosystems & Environment, 2005. 108(2): p. 145-154. • Dissanayake, N.P.J., Summerscales, J., Grove, S.M., Singh, M.M., Energy use in production of flax fibre for the reinforcement in composites, in Advanced Composites Manufacturing Centre, School of Engineering, University of Plymouth. 2009. p. 1-25. (In submission) • Azapagic, A., Perdan, S., Clift, R., Polymers, the Environment and Sustainable Development. 2003: John Wiley & Sons. • Azapagic, A., Perdan, S., Clift, R. , Sustainable Development in Practice - Case Studies for Engineers and Scientists. 2004: John Wiley & Sons. • Azapagic, A., Aquatic Toxicity Potential. Private Communication, 25/02/2009.
Acknowledgements for their respective travel grants Faculty of Technology for contribution to registration fees School of Engineering for the balance of conference costs
Thank you for your attention. Any questions?