properties and performance of evoh in geosynthetic applications presented by: robert armstrong...
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Properties and performance of EVOH in geosynthetic applications
Presented by: Robert ArmstrongKuraray America Inc.
phone (281) 474-1576 [email protected]
Kuraray Company. Ltd. Established in Kurashiki
Japan in 1926 to pursue themanufacture of synthetic
materials.
First product was rayon fiber
Changed name to KurashikiRayon Company in 1949.
Grew organically in diversifiedsynthetic chemistry while
expanding globally.
Kurashiki
World-leading businessesPoval Optical-use Poval film EVAL (EVOH resin)
Isoprene chemicalsOne-of-a-kind products derived from
synthetic isoprene (MMB, MPD, etc…)
Methacrylic resin(Molding materials for light-guide plates)
KURALONKURALON K- Ⅱ PVA fiber
CLARINOMan-made leather
GENESTARHeat-resistant polyamide resin
VECTRANHigh-strength polyarylate fiber
Focus on Federal and State Regulations including the
Clean Air & Water Act
Personal and Environmental Protection
EVOH can reduce VOC and CO2e emissions to air, soil and ground water
E V O H E V O H E V O H E V O H E V O H
E V O H E V O H E V O H E V O H E V O H
Ground Water
CO2, CH4, H2S
BTEX, TCE, PCE
Air
Soil
What is EVOH? Ethylene Vinyl Alcohol (EVOH) is one of many semi-crystalline thermoplastic copolymers – first produced in the US
in 1986
Key properties of EVOH
Oil resistance
Gas Barrier (O2, CO2, etc)
Extrudable
Recyclability
Solvent Barrier
Abuse resistance
Hydrocarbon Barrier
Odor Barrier
EVOH PROPERTIES
3235
27
384448
Ethylene M
olar Percent
• Better gas & solvent barrier• Higher Melt temperature
Better:• thermal stability• water vapour barrier• flexibility• Thermoform-ability, orient-ability
Effect of mol% on properties of EVOH
EVOH is a random copolymer of
Ethylene and Vinyl ALcohol
(CH2-CH2)m (CH2-CH)n
OH
EVOH vs. HDPE Gas Barrier Properties
GasEVOH* HDPE**
Nitrogen 0.019 190
Oxygen 0.25 2300
Carbon Dioxide 0.6 17526
Sulfur Dioxide 0.3 21844
Methane 0.4 2845
Volumetric permeation rate in (cc.20µ/m2.day.atm)Conditions: 23°C – 0% RH (ASTM D1434T)* ASTM D1434 at Kuraray lab – 32mol% EVOH **Permeability Properties of Plastics and Elastomers, Massey, 2nd Edition
Volumetric permeation rate in (cc.20µ/m2.day.atm)Conditions: 23°C – 0% RH (ASTM D1434T)* ASTM D1434 at Kuraray lab – 32mol% EVOH **Permeability Properties of Plastics and Elastomers, Massey, 2nd Edition
EVOH vs HDPE – solvent resistance
SolventEVOH * HDPE**
trichloroethyelene 3.1x10-17 4.0x10-13
toluene 3.1x10-17 3.0x10-13
Diffusion coefficient Dg in m2/s
*Kiwa NV report April 2008 for EVAL Europe N.V** Sangam and Rowe, Migration of dilute aqueous organic pollutants through a HDPEgeomembrane, Geotextiles and Geomembranes 19 (2001) 329-357
Diffusion coefficient Dg in m2/s
*Kiwa NV report April 2008 for EVAL Europe N.V** Sangam and Rowe, Migration of dilute aqueous organic pollutants through a HDPEgeomembrane, Geotextiles and Geomembranes 19 (2001) 329-357
Diffusion coefficient Dg of solvents in EVOH and HDPEDiffusion coefficient Dg of solvents in EVOH and HDPE
Wide ranging studies of solvent resistance (weight gain, retention of physical properties etc) established excellent performance of EVOH for
automotive and ag-chemical applications
Wide ranging studies of solvent resistance (weight gain, retention of physical properties etc) established excellent performance of EVOH for
automotive and ag-chemical applications
Example of EVOH solvent barrier…
Reference Fuel C 50% toluene
50% isooctane
Reference Fuel C 50% toluene
50% isooctane
Geomembranes in landfill liners
CCL
Compacted
Clay Liner
GCL
Geosynthetic Clay Liner
Polymer Geomembrane
New Application Development
Addition of EVOH to geomembrane liner would improve VOC and hydrocarbon barrier of primary or secondary liner
Diffusion Leakage
Concepts for landfill liners Subtitle D
Polyethylene or other polyolefin
Adhesive
EVOH
Primary liner
Polyethylene or other polyolefin
EVOH could be incorporated into primary liner or into secondary liners or GCL below primary liner to improve VOC barrier
60mil Primary liner HDPE + EVOH
60 mil Primary liner
Secondary liner or GCL with EVOH
EVOH
Concept for double liner systemsPrimary liner 60mil HDPE
EVOH could be incorporated into 40mil primary liner to improve VOC barrier and reduce system cost
Primary liner 40 mil LLDPE + EVOH
Secondary liner 60 mil HDPE
EVOH
Secondary liner 60mil HDPE
Leachate collection systemLeachate collection system
Potential for performance improvement
Reduction in total flux of toluene by using EVOH in a 40~60 mil geomembrane vs 60mil HDPE
Toluene concentration 25mg/L (25ppm). Service temperature 24°C
Reduction in total flux of toluene by using EVOH in a 40~60 mil geomembrane vs 60mil HDPE
Toluene concentration 25mg/L (25ppm). Service temperature 24°C
60mil HDPE versus 40~60 mil liner with 5% EVOH60mil HDPE versus 40~60 mil liner with 5% EVOH
Evaluation of model geomembranes• Samples
– Monolayer samples from Chevron Phillips Chemical Co. LP. Marlex® K306 medium density polyethylene (MDPE) and LyondellBasell Industries Hifax® CA10A thermoplastic polyolefin (TPO), or flexible polypropylene (fPP).
– Coex samples – see figure
• Physical Testing– Samples submitted to Chevron Phillips
Chemical Co. LP. For physical properties testing
• Barrier Testing– Permeation reported is the rate of mass
transport of a solvent through each model geomembrane sample in grams/m2.day.
– The permeation experiments were conducted as an isostatic permeation test by MOCON Inc.
60mil coex samples
Tie 50µm
HDPE 687µm
EVOH 50µm
Barrier of 60mil model GM to toluene
Permeation of toluene vapor through model 60 mil geomembraneEVOH reduces permeation from 100 grams/sq.m.day to <0.005 grams/sq.m.day at 40°C (104°F)
MOCON isostatic solvent permeation test equipment
Physical properties of a 60 mil HDPE monolayer vs. coex model geomembrane
Properties Units HDPE HDPE + EVOH
Tensile Stress at Yield MD MPa 18.9 20.4
Tensile Stress at Break MD MPa 34.3 24.5
Tensile Elongation at Yield MD % 12 9.2
Tensile Elongation at Break MD % 657 556
Tensile Modulus MPa 651.0 827.9
Total Energy for Puncture N 667 730
Field trials for landfill liners
1. Lab scale at GSI (Aug 5 ’10)
• Background at site = 6 ppm
• LLDPE pouch vs LLDPE+EVOH coex
• Provided by Raven Industries
• 1 gal SUNOCO gasoline each pouch
Landfill trial
WM site in Pennsylvania
GSI Field Trials: George R. Koerner Ph.D., P.E. & CQA
Geosynthetic Institute, 475 Kedron Ave. Folsom PA USA
(610) 522-8440 www.geosynthetic-institute.org
GSI Trial Results
GSI Field Trials: George R. Koerner Ph.D., P.E. & CQA
Geosynthetic Institute, 475 Kedron Ave. Folsom PA USA
Concepts for landfill covers
Monolithic intermediate cover
Polyethylene or other polyolefin
EVOH could be incorporated into intermediate covers to improve VOC, CH4, H2S and CO2e vapor barrier
Intermediate cover with EVOH
EVOH
Potential for improvement in performance is significant…
Improve efficiency of LFG collectionReduce emissions of CO2e – Title V permits
Title V – Green House Gas (GHG) Tailoring Rule
• Title V Clean Air regulation will cover a facility which has a potential to emit (PTE) 100,000 tpy or more green house gases on a CO2e basis.
• Phased-in approach.
• Regulated pollutant is GHGs – combination of 6 gases.
• Threshold is potential-to-emit (PTE) in units of short tons carbon dioxide equivalent (CO2e).
Many LFG models assume only 75% of LFG can be collected using best available technology
Reference Iowa Dept Natural Resources – Greenhouse Gas Regulations & Landfills – Sept 27, 2010
Example Title V CalculationFacility has potential emissions of 5,000 tons/year CO2;
5,000 tons/year CH4; 0.5 tons year N2O
CO2e = (5000*1)+(5000*21)+(0.5* 310) = 110,155 tpy
Pollutant tons/year GWP tons/year CO2e
CO2 5,000 1 5,000
CH4 5,000 21 105,000
N2O 0.5 310 155
Total 110,155
Global Warming Potential (GWP) – An index that allows for comparison of various greenhouse gases. It is the radioactive forcing that results from the addition of 1 kilogram
of a gas to the atmosphere, compared to an equal mass of carbon dioxide.
Reference Iowa Dept Natural Resources – Greenhouse Gas Regulations & Landfills – Sept 27, 2010
Potential reduction in methane emissions using landfill covers
Fugitive emissions reported from landfills with soil cover is 100 to 200 kg/acre.day EVOH barrier is only 1mil thick – could incorporated into thin films for daily covers
Conclusion• Existing geomembranes comprised of polypropylene,
polyethylene and polyvinylchloride are excellent hydraulic and heavy metal barriers. – However these materials are NOT good barriers for volatile
organic compounds migrating by diffusion
• Inclusion of EVOH by coextrusion into select geomembrane designs would minimize diffusive migration of VOC’s and radon– Significantly improved protection of air, soil and water quality.
• EVOH offers the potential of improved VOC barrier and lower system cost without significant effects on form and function of geomembranes
Value of EVOH in personal and environmental protection
BTEX, TCE Landfill CO2, CH4,
H2S Bioreactor
Radon & Vapor Intrusion
Protection of health and the environment
(air, soil and water quality)
Reducing remediation costs and potential liability
Protection of health and the environment
(air, soil and water quality)
Reducing remediation costs and potential liability
EVOH linerEVOH liner
Questions are welcome.
Presented by:
Robert B. Armstrong
phone (281) 474-1576 [email protected]
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