Presentation on theme: "1 Are Natural Fiber Composites Environmentally Superior to Glass Fiber Reinforced Composites? S. Joshi L. T. Drzal A.K. Mohanty Michigan State University."— Presentation transcript:
1 Are Natural Fiber Composites Environmentally Superior to Glass Fiber Reinforced Composites? S. Joshi L. T. Drzal A.K. Mohanty Michigan State University International LCA Conference Seattle, Sept 22-25, 2003
2 Why bio-based polymers and natural fibers? Environmental Advantages? zRenewable raw material base zBiodegradable zReduced fossil fuel and resource consumption zLower Greenhouse gas emissions zLower overall emissions and environmental impacts Economic advantages? (Short v/s Long run) zRising petroleum prices, technological progress and scale economies
3 Bio-based polymers zCellulosic plastics, PHA, PLA and others Controversial zRenewable base? zPerformance and cost? zBiodegradable? zEnergy use? zGHG emissions? zEmissions and environmental impacts? zData availability and quality? No Studies on all bio-composites?
5 Life Cycle of GFRP Glass manufacture Glass Fiber manufacture Monomer manufacturing Polymer manufacturing FRP component manufacture Component Use Component End of Life management -Landfill -Incinerate -Recycle?
6 Life Cycle of NFRP Fiber crop Cultivation Natural Fiber Extraction Monomer manufacturing Polymer manufacturing NFRP component manufacture Component Use Component End of Life management -Landfill -Incinerate -compost Compatibilizer production
7 Empirical Studies zWotzel et al (1999) yHemp-Epoxy v/s ABS auto side panel (Audi A3) z Corbiere-Nicollier et al (2001) yChina reed-PP v/s Glass-PP transport pallet (Swiss Federal Institute of Technology) zSchmidt and Meyer (1998) yHemp-EPDM-PP v/s GF-EPDM-PP auto insulation component (Ford car) zDiener and Siehler (1999) yGF-PP v/s Flax-PP auto floor panel ( Mercedes A car)
8 Issues zComparative basis (material and application) zPerformance equivalence zLife cycle stages modeled/boundaries zData source/approximation/details zEnd of life management and credits for recycled material/energy zEnvironmental impacts considered and aggregation
9 Materials compared zWotzel et al (1999): auto side panel yHemp(66%v )-Epoxy(36%v ) v/s yABS (100%) z Corbiere-Nicollier et al (2001):transport pallet yChina reed (52.8%w)-PP(47.2%w) v/s yGlass (41.8%w) – PP(58.2%w) zSchmidt and Meyer (1998) auto insulation component yHemp (30%w) –EPDM(6.4%w) - PP(63.6%w) v/s yGF – EPDM – PP (??) zDiener and Siehler (1999) :Auto under floor panel yGF-PP v/s Flax-PP (??)
10 Performance zWotzel:Auto side panel yDo not discuss performance. zCobiere:Pallet ySatisfying service requirement(1000km/yr for 5 years) yTheoretical mixture % to achieve equivalent stiffness zSchmidt: Auto Insulation yIntensive technical checks found hemp fibers are able to replace glass fibers in the specific application zDiener: Auto Under floor panel ySuccessfully passed all tests
11 LC stages and Data zWotzel: Auto side panel yLC stages up to component mfg considered yHemp: cultivation, fiber extraction modeled yABS, Epoxy : from APME ecoprofiles zSchmidt: auto insulation yFull LC with 50% landfill,50% incineration yPP,EPDM,GF, fuels from APME/IDEA yHemp data a: approximation from available data on flax, maize cultivation (educated guesses) yNo compatibilizer zCorbiere(pallet) yFull LC stages including compatibilizer considered and modeled
12 Conclusions from studies zAll studies provide a LCI of components with some degree of impact aggregation zNatural fiber composites have environmental benefits over comparable designs with conventional materials yCED savings of 88.9MJ/component yEco-indicator impacts less by 8-17% yCML indicator points for human toxicity less by 57%, aquatic toxicity by 39%, GHG by 46% zLittle intermediate details zHOW GENERALIZABLE ARE THESE RESULTS?
13 Drivers of environmental superiority of NFRP zNatural fiber production v/s glass fiber production emissions zHigher fiber % (substitution of base polymer and GF with lower emission NF) zWeight reduction (Higher fuel efficiency during use phase) zEnergy credits due to EOL fiber burning zGWP credits for carbon sequestration zHigher N 2 O & eutrophication due to cultivation
16 Weight Reduction ComponentStudyNFRP component Base component Auto side panelWotzel et al820 g (hemp- epoxy) 1125g (ABS) Auto insulationSchmidt2.6 kg (hemp-PP) 3.5kg (GF-PP) Transport PalletCorbiere11.77kg (CR-PP) 15kg (GF-PP)
17 Use-phase fuel reduction zFuel reduction coefficients* yGasoline vehicles x0.34-0.48L/100kg/100km xOr 6.8-9.6 L/kg/200,000km-vehicle life time xFord Model 5.6 L/10000km yDiesel vehicles x 0.29-0.33 L/100kg/100km xOr 5.8-6.6L//kg/200000km zComponent transportation fuel use savings in non-auto applications * Source: Eberle and Franz,1998 (SAE-TLC)p139)
18 Effects of Fuel Savings z1 kg weight savings due to NF substitution implies avoided environmental effects of the production and burning of ~7 L of gasoline. Energy ~273 MJ (NF = 3.4 MJ) CO2 emissions ~ 17.76kg (NF=0.64kg) SOx emissions ~ 5.78g (NF=1.2g) NOx emissions ~163g (NF=0.95g) zFor auto applications the use phase weight reduction-fuel savings effects totally dominate other effects and life cycle stages
19 Other Benefits zCarbon sequestration in hemp ~ 0.79kg CO2/kg fiber zEnergy recovery from fiber burning ~10 MJ/kg zRENEWABLE/LOCAL Material base
20 CONCLUSIONS zSubstitution of glass fibers with natural fibers is environmentally beneficial. zIn automotive applications, environmental benefits due to weight reduction-fuel use effects during the use phase of the auto dominate the environmental effects of all other stages zWhen combined with cheaper prices, the future of NFRP in auto/transport applications is bright zTechnologies for achieving equivalent/superior component performance should be the focus of research
21 Acknowledgement Funding for this research was provided by NSF-PREMISE grant number 225925-2002