Catalytic Destruction of Chlorinated Solvents in Soil Vapor
Student: Jagoda Vojvodic
Mentor: Eric Betterton
University of Arizona Space Grant
Superfund
• Federal government’s program to clean up hazardous waste sites from a priority list of 1246
• Common contaminants:- Trichloroethylene (TCE)- Tetrachloroethylene (PCE)
Priority List of Hazardous Substances
1 Arsenic
2 Lead
3 Mercury
4 Vinyl Chloride
5 POLYCHLORINATED BIPHENYLS
6 Benzene
7 Cadmium
8 POLYCYCLIC AROMATIC HYDROCARBONS
9 BENZO(A)PYRENE
10 BENZO(B)FLUORANTHENE
11 CHLOROFORM
12 DDT, P,P'-
13 AROCLOR 1254
14 AROCLOR 1260
15 DIBENZO(A,H)ANTHRACENE
16 *TRICHLOROETHYLENE
Motivation
• Pose risk to the human and ecological health from groundwater contamination
• Current remedies with activated carbon are too expensive and do not destroy the contaminant
Propane as reductant
• Economic alternative to using Hydrogen in conversion of PCE
• Concentrated on experiments of propane conversion under various conditions
HClCOOHCPCE
HClCOOHPCE
2283
222
Lab Process Flow DiagramPCE + reductant + O2 CO2 + H20 + HCl
Cross section of reactor
Propane Conversion dataVarying amount of oxygen from 5% to 40%
1% Propane Exps, Jan 2008
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
400 425 450 475 500 525 550 575 600
Pro
pane
Rem
oval
5%
10%
12%
20%
40%
Varying propane concentration,oxygen concentration constant
10%, 88%N2
0
10
20
30
40
50
60
70
80
90
100
340 390 440 490 540 590 640 690
Catalyst Temperature
%R
em
oval
1.00%
0.50%
2.00%
Propane effect on PCE conversion
Conclusion
• Can destroy the chlorinated solvents using a Pt/Rh catalyst effectively
• Need 1.5% Propane to destroy 500ppm of PCE at 440 C
Price Comparison
At >1% Propane, we can destroy 1lb of PCE using:
Propane: $5
Hydrogen: $100
Acknowledgements
NASA Space Grant
Susan Brew
Eric Betterton, Eduardo Saez, Robert Arnold, Brian Barbaris
Erik Rupp, Marty Willinger, Suzanne Richards, Desiree Polson
