Properties and performance of
EVOH in geosynthetic applications
Presented by: Robert Armstrong
Kuraray America Inc.
phone (281) 474-1576
robert.armstrong@kurarayamerica.com
Kuraray Company. Ltd.
Established in Kurashiki
Japan in 1926 to pursue the
manufacture of synthetic
materials.
First product was rayon fiber
Kurashiki
Changed name to Kurashiki
Rayon Company in 1949.
Grew organically in diversified
synthetic chemistry while
expanding globally.
World-leading businesses
Poval
KURALON
KURALON K-Ⅱ PVA fiber
Optical-use Poval film
Isoprene chemicals
One-of-a-kind products derived from
synthetic isoprene (MMB, MPD, etc…)
EVAL (EVOH resin)
Methacrylic resin
(Molding materials for light-guide plates)
CLARINO
VECTRAN
GENESTAR
Man-made leather
High-strength polyarylate fiber
Heat-resistant polyamide resin
Personal and Environmental Protection
• Radon barrier
• Secondary containment
liners
• Landfill liners
• Oil sand tailings
• Heap leach mining
• Steel pipe coatings
Focus on Federal and State
Regulations including the
Clean Air & Water Act
Personal &
Environmental
Protection
EVOH can reduce VOC and CO2e emissions to air, soil
and ground water
EVOH
EVOH
EVOH
EVOH
EVOH
Air
CO2, CH4, H2S
BTEX, TCE, PCE
Soil
EVOH
EVOH
EVOH
Ground Water
EVOH
EVOH
What is EVOH?
Ethylene Vinyl Alcohol (EVOH) is one
of many semi-crystalline thermoplastic
copolymers – first produced in the US
in 1986
Polymers
(Plastics)
Thermosets
Thermoplastics
Amorphous
polymers
Semi-crystalline
polymers
Copolymers
Homopolymers
Low & High
Density
polyethylene
Ethylene VinylAcetate
Ethylene VinylAlcohol
(EVOH)
Linear Low
Density
Polyethylene
Nylons
Key properties of EVOH
Gas Barrier (O2, CO2, etc)
Oil resistance
Abuse resistance
Extrudable
Solvent Barrier
Recyclability
Hydrocarbon Barrier
Odor Barrier
EVOH PROPERTIES
Effect of mol% on properties of EVOH
• Better gas & solvent barrier
• Higher Melt temperature
Ethylene Molar Percent
27
32
35
38
44
48
Better:
• thermal stability
• water vapour barrier
• flexibility
• Thermoform-ability, orient-ability
EVOH is a random copolymer of
Ethylene and Vinyl ALcohol
(CH2-CH2)m
(CH2-CH)n
OH
EVOH vs. HDPE Gas Barrier Properties
EVOH*
HDPE**
Nitrogen
0.019
190
Oxygen
0.25
2300
Carbon Dioxide
0.6
17526
Sulfur Dioxide
0.3
21844
Methane
0.4
2845
Gas
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
Diffusion coefficient Dg of solvents in EVOH and HDPE
EVOH *
HDPE**
trichloroethyelene
3.1x10-17
4.0x10-13
toluene
3.1x10-17
3.0x10-13
Solvent
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 HDPE
geomembrane, Geotextiles and Geomembranes 19 (2001) 329-357
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
New Application Development
Geomembranes in landfill liners
CCL
Compacted
Clay Liner
Polymer Geomembrane
GCL
Addition of EVOH to
geomembrane liner would
improve VOC and hydrocarbon
barrier of primary or secondary
liner
Geosynthetic Clay
Liner
Diffusion
Leakage
Concepts for landfill liners Subtitle D
60mil Primary liner HDPE + EVOH
Polyethylene or other polyolefin
EVOH
Adhesive
Primary liner
Polyethylene or other polyolefin
60 mil Primary liner
Secondary liner or GCL with EVOH
EVOH
EVOH could be incorporated into primary liner or into secondary
liners or GCL below primary liner to improve VOC barrier
Concept for double liner systems
Primary liner 60mil HDPE
Primary liner 40 mil LLDPE + EVOH
EVOH
Leachate collection system
Leachate collection system
Secondary liner 60 mil HDPE
Secondary liner 60mil HDPE
EVOH could be incorporated into 40mil primary liner to improve VOC
barrier and reduce system cost
Potential for performance improvement
60mil HDPE versus 40~60 mil liner with 5% EVOH
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
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
HDPE 687µm
Tie 50µm
EVOH 50µm
Barrier of 60mil model GM to toluene
MOCON isostatic solvent
permeation test equipment
Permeation of toluene vapor through model 60 mil geomembrane
EVOH reduces permeation from 100 grams/sq.m.day to <0.005 grams/sq.m.day at 40°C (104°F)
Physical properties of a 60 mil HDPE
monolayer vs. coex model geomembrane
Properties
Units
HDPE
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
MPa
651.0
827.9
N
667
730
Tensile Modulus
Total Energy for Puncture
HDPE + EVOH
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
gkoerner@dca.net
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
EVOH could be incorporated into intermediate covers to
improve VOC, CH4, H2S and CO2e vapor barrier
Intermediate cover with EVOH
Monolithic intermediate cover
Polyethylene or other polyolefin
EVOH
Potential for improvement in performance is
significant…
Improve efficiency of LFG collection
Reduce 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 Calculation
Facility has potential emissions of 5,000 tons/year CO2;
5,000 tons/year CH4; 0.5 tons year N2O
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
CO2e = (5000*1)+(5000*21)+(0.5* 310) = 110,155 tpy
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
CO2, CH4,
H2S
Bioreactor
BTEX, TCE
Landfill
EVOH liner
Protection of health and the environment
(air, soil and water quality)
Reducing remediation costs and potential liability
Radon &
Vapor
Intrusion
Questions are welcome.
Presented by:
Robert B. Armstrong
phone (281) 474-1576
robert.armstrong@kurarayamerica.com
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