Green Alternative to PVC Scott Gibb Advisor: Eric Beckman Department of Chemical and Petroleum...
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Transcript of Green Alternative to PVC Scott Gibb Advisor: Eric Beckman Department of Chemical and Petroleum...
Green Alternative to PVC
Scott GibbAdvisor: Eric Beckman
Department of Chemical and Petroleum Engineering
Research Goals
• To design a feasible alternative material for replacing PVC piping systems.
• Develop a process for product design that incorporates a multiple metric system.
• Screen potential alternative materials for product design using life cycle assessment.
• Eventually prepare and test sample of proposed alternative materials.
Current/Previous Replacements
• Polybutylene– PB had problems with oxygen permeation and
deterioration of the acetal fittings resulting in leaks that requires entire homes/building to be replumbed.
• Borealis– They make polypropylene resins for pipe.– The mechanical properties of Borealis’ pipe resins
do not compare to that of PVC.– PP is more expensive than PVC.
• Copper– Copper is expensive and requires a skilled laborer to
install. (Still the standard for water supply piping)
Why Replace PVC?
• Chlorine requires ~3000 kWh/ton to produce.• PVC uses ~1/3 of the world’s chlorine.• Some chlorine production still involves the
use of mercury or asbestos.• PVC’s monomer, vinylchloride monomer
(VCM), and precursor, ethylene dichloride (EDC), are known carcinogens.
• Many environmental pollutants/toxicants are chlorine based.
Chlorine Tree
• ~1/3 of Cl2 goes to PVC.
• ~1/2 of PVC goes to piping/tubing.
Chlorine Production
• Chlorine is produced from a brine solution (salt water) in electrolytic cells.
• NaCl + H2O
• ½Cl2 + NaOH + ½H2
• There are three types of cells:– Mercury Cells– Diaphragms Cells– Membrane Cells
PVC Production
NaCl + H2O Cl2 + NaOH
Cl ClPVC+
HCl
Cl
+ 0.5O2 – H2O
How to Replace PVC for Piping
• For an alternative material to replace PVC piping, the alternative material must have some advantage over PVC.
• Commonly the only advantage consumers care about is upfront cost.
• Using only upfront cost in decision making will not likely result in a better product.
• It is possible to have a product that is better and cheaper if multiple metrics are assessed during the design of the product.
• To achieve this off the shelf alternatives may not work.
Metrics
• Functional metric.– Can the alternative material perform the same
function as PVC piping?– Does the alternative material have similar, higher
or lower values for mechanical strength properties?
• Economic metric.– Is the alternative material similar priced or cheaper
to purchase, install, and maintain than PVC?
• Environmental metric.– Is the alternative material more sustainable and
have a lower environmental impact than PVC?
Alternative Comparison
• Properties of off the shelf alternative materials and two composites.
Cw
($/kg)(MPa)
(g/cm3)
t(in)
m(kg/ft)
Cl,p
($/ft)
PVC 1.1 51.3 1.4 0.034272 0.042935 0.048909
Cw
($/kg)(MPa)
(g/cm3)
t(in)
m(kg/ft)
Cl,p
($/ft)
PVC 1.1 51.3 1.4 0.034272 0.042935 0.048909
ABS 2.2 37.9 1.04 0.04639 0.042815 0.098356
PE 1.72 25.2 0.91 0.069768 0.055437 0.101193
PP 1.54 33.8 0.94 0.052017 0.043224 0.069777
Cw
($/kg)(MPa)
(g/cm3)
t(in)
m(kg/ft)
Cl,p
($/ft)
PVC 1.1 51.3 1.4 0.034272 0.042935 0.048909
ABS 2.2 37.9 1.04 0.04639 0.042815 0.098356
PE 1.72 25.2 0.91 0.069768 0.055437 0.101193
PP 1.54 33.8 0.94 0.052017 0.043224 0.069777
PP-Glass 1.57 60 1.106 0.029303 0.029099 0.04703
PP-CR 1.21 52 1.164 0.033811 0.035228 0.044132
Off the Shelf Comparison
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Acidific
ation
Air
Ecoto
xcity
Air
Ecoto
xicity
Soil
Ecoto
xcity
Wat
er
Eutro
phica
tion
Air
Eutro
phica
tion
Wat
er
Global
War
ming
Air
Human
Hea
lth C
ance
r Air
Human
Hea
lth C
ance
r Soil
Human
Hea
lth C
ance
r Wat
er
Human
Hea
lth C
riter
ia Air-
Point S
ourc
e
Human
Hea
lth N
on C
ance
r Air
Human
Hea
lth N
on C
ance
r Soil
Human
Hea
lth N
on C
ance
r Wat
er
Ozone
Dep
letion
Air
Smog
Air
No
rma
lize
d Im
pa
cts
ABS pipe
HDPE pipe
PP pipe
PVC pipe
Comparison of TRACI Impacts
00.10.20.30.40.50.60.70.80.9
1
Acidific
ation
Air
Ecoto
xcity
Air
Ecoto
xcity
Wat
er
Eutro
phica
tion
Air
Eutro
phica
tion
Wat
er
Global
War
ming
Air
Human
Hea
lth C
ance
r Air
Human
Hea
lth C
ance
r Wat
er
Human
Hea
lth C
riter
ia Air-
Point S
ourc
e
Human
Hea
lth N
on C
ance
r Air
Human
Hea
lth N
on C
ance
r Wat
er
Ozone
Dep
letion
Air
Smog
Air
No
rmal
ized
Imp
acts
PP-CR Pipe
PP-Glass Pipe
PP Pipe
PVC Pipe
Life Cycle Assessment
• GaBi LCA software is used to develop LCAs of PVC as well as potential alternatives.
Areas of Overlap with other Disciplines
• Mechanical/Material Engineering– Material properties
• Civil/Environmental Engineering– LCA– Sustainable design
• Industrial Engineering– System design/optimization
Questions?