1. Green Alternative to PVC Scott Gibb Advisor: Eric Beckman Department of Chemical and Petroleum Engineering

2. 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.

3. 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)

4. 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.

5. Chlorine Tree ~1/3 of Cl 2 goes to PVC. ~1/2 of PVC goes to piping/tubing.

6. Chlorine Production Chlorine is produced from a brine solution (salt water) in electrolytic cells. NaCl + H 2 O  ½Cl 2 + NaOH + ½H 2 There are three types of cells: –Mercury Cells –Diaphragms Cells –Membrane Cells

7. PVC Production NaCl + H 2 O Cl 2 + NaOH Cl PVC + HCl Cl + 0.5O 2 – H 2 O

8. 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.

9. 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?

10. Alternative Comparison Properties of off the shelf alternative materials and two composites. C w ($/kg)  (MPa)  (g/cm 3 ) t (in) m (kg/ft) C l,p ($/ft) PVC1.151.31.40.0342720.0429350.048909 C w ($/kg)  (MPa)  (g/cm 3 ) t (in) m (kg/ft) C l,p ($/ft) PVC1.151.31.40.0342720.0429350.048909 ABS2.237.91.040.046390.0428150.098356 PE1.7225.20.910.0697680.0554370.101193 PP1.5433.80.940.0520170.0432240.069777 C w ($/kg)  (MPa)  (g/cm 3 ) t (in) m (kg/ft) C l,p ($/ft) PVC1.151.31.40.0342720.0429350.048909 ABS2.237.91.040.046390.0428150.098356 PE1.7225.20.910.0697680.0554370.101193 PP1.5433.80.940.0520170.0432240.069777 PP-Glass1.57601.1060.0293030.0290990.04703 PP-CR1.21521.1640.0338110.0352280.044132

11. Life Cycle Assessment GaBi LCA software is used to develop LCAs of PVC as well as potential alternatives.

12. Areas of Overlap with other Disciplines Mechanical/Material Engineering –Material properties Civil/Environmental Engineering –LCA –Sustainable design Industrial Engineering –System design/optimization

13. Questions?

14. Professors with Similar Interests Pitt –Eric Beckman –Sachin Velankar –Amy Landis CMU –Terry Collins –Scott Matthews CAMPINAS –Vanessa Gomez