Carpet Waste Gasification:
Technical, Economic,
Environmental Assessment for
Carpet Mills
An Interim Presentation
ENCH 4300—Capstone
UT Chattanooga
April 7, 2015
Advisor: Dr. Jim Henry
Jordan Buecker
Christopher Burns
Katharine Davis
Hemali Dholakia
Kevin O’Brien
Outline
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Problem Statement
Principle of Gasification
Methodology
Proposed Systems
Syngas Uses
Environmental Analysis
Economics
Conclusions
Problem Statement
• 250 tons per day of post-consumer
carpet (PCC)
• Currently pay disposal fees
• Reclaim a portion of the chemical
energy from the PCC
Problem Statement
• PCC has lower heating value of 8,800 Btu/lb
o Bituminous coal LHV = 11,000 Btu/lb
o Natural gas LHV = 20,000 Btu/lb
• Gasification Processes PCC considered
o Produce syngas
• Syngas LHV = 8,000-12,000 Btu/lb
Principle of Gasification
Methodology
• 250 tons/day of post consumer carpet
• Carpet composition (wt%)
Component
Percentage of Carpet
(wt%)
Polypropylene (PP)
17
Calcium Carbonate
(CaCO3)
35
Polyethylene
Terephtalate (PET)
6
Nylon 6 (N 6)
17
Nylon 6,6 (N 6,6)
14
Styrene Butadiene
Rubber (SBR)
11
Percentage removed
pre-gasification (wt%)
80
100
Methodology
Material
PP
CaCO3
PET
SBR
N66
Heat of
Combustion
(BTU/lb)
-18600
800
-9500
-18900
-13800
Flowrate (lb/hr)
1700
700
630
1100
1400
MMBTU/hr
-32
0.6
-6
-21
-19
Total 79 MM BTU/hr
Methodology
• Employed ChemCad modeling
software
• Material balance
• Energy balance
Proposed Systems
Air Gasifier
Proposed Systems
Air Gasifier
• N2 presence reduces heating value
• Produces NOx
Proposed Systems
O2 Gasifier
Proposed Systems
O2 Gasifier
• Capital increase due to N2 separation
• Capital decrease due to volumetric
flow from the gasifier
Proposed Systems
Steam Gasifier
Proposed Systems
Steam Gasifier
• Lower Temperature
• Produces CH4 (higher heating value
syngas)
Current Syngas Use
Exhaust
Steam
Air
Syngas
Boiler
Plant Use
Potential Syngas Use
Exhaust
High Pressure Steam
Air
Boiler
Syngas
Steam
Turbine
Condensate
Low Pressure Steam
Condenser
Potential Syngas Use
Low Temp Exhaust
Boiler
High Pressure Steam
Hot Exhaust
Air
Syngas
Gas
Turbine
Steam
Turbine
Work
Work
Energy Recovery
Gasifier
Air
O2
Steam
MM
BTU/h
58
58
35
BTU/lb
PCCW
5800
5800
3500
Pollutants
Gasifier
lb
CO2/MM
Coal
Coal
lb/h CO2
BTU
compare lb/h NOx compare
Air 14000
O2 14000
Steam 11000
240
240
310
13%
13%
48%
300 -14%
negligible
negligible
Interim Conclusions
• Technologically and
Environmentally Feasible
• Economic Analysis will be
performed
Questions We Have
• What were the strong points?
• What can be improved upon?
• What can be omitted?