Reformate Desulfurization for Logistic ...€¦ · Reformate Desulfurization for Logistic...
Transcript of Reformate Desulfurization for Logistic ...€¦ · Reformate Desulfurization for Logistic...
Reformate Desulfurization for Logistic SOFC Power SystemsSOFC Power SystemsSOFC Power Systems
Hongyun Yang1, Troy Barron1 and Bruce Tatarchuk2
1. IntraMicron Inc., 368 Industry Drive, Auburn, AL, 36832, y , , ,2. Dept. of Chem. Eng., Auburn University, AL, 36849
June 16, 2010
th 44th P S C f
- Proprietary and Business Sensitive - 1111
the 44th Power Sources ConferenceLas Vegas, NV
IntraMicron Inc.
IntraMicron Inc is a small business company located at Auburn, AL. Its R&D (1) Filt ti (2) D lf i ti (3) Fi h T h S th i (4) COcovers:(1) Filtration; (2) Desulfurization; (3) Fischer Tropsch Synthesis; (4) CO
oxidation.
- Proprietary and Business Sensitive - 22
Microfibrous Entrapped Catalyst Particles
Polishing sorbents for gas phase desulfurization
Adsorbent for liquid phase desulfurization
Desulfurization Sorbents/Adsorbents
70
80
t)
Cu-ZnO/SiO2Low Temperature Gas Phase
40
50
60
70
of S
/ g o
f Sor
bent Fe-ZnO/SiO2
Co-ZnO/SiO2Ni-ZnO/SiO2
Mn-ZnO/SiO2
ZnO/SiO2
Commercial ZnO
Desulfurization Sorbent: Cu-ZnO/SiO2, (Patent Applied for)
10
20
30
40
BT
Cap
acity
(mg
ZnO(Regn)
Liquid Phase Desulfurization Adsorbents:Ag2O/TiO2 for JP-5
0Sorbents
After Desulfurization
Current capacity: ~6 mg S/g adsorbent
Ultralow Sulfur Diesel Sample
DMDBT and Derivatives
- Proprietary and Business Sensitive -
Outline
• Sulfur IssueSulfur Issue• Reactor Design and Bed Configuration• Desulfurization & Regeneration Performance• Desulfurizer ConstructionDesulfurizer Construction• Conclusion
A k l d• Acknowledgements
- Proprietary and Business Sensitive - 44
Sulfur Issue
• Typical Fuel Cells Have Low Sulfur Threshold: – 0.1 ppmv most for PEM Fuel Cells– 2~3 ppmv for typical Solid Oxide Fuel Cells
• Sulfur Content in Logistic Fuels (ca JP-5 JP-8)Sulfur Content in Logistic Fuels (ca. JP 5, JP 8) – i.e. 500~3000ppmw, equivalent to 50~300 ppmv after converted
to reformates in reformers.• Sulfur Removal Techniques• Sulfur Removal Techniques
– Pre Reformer Desulfurization– Post Reformer Desulfurization
• Post Reformer Desulfurization Using Reactive Sorbents– ZnO, CuO, Fe2O3 etc.– High sulfur capacity (i.e. 392 mg S/g ZnO), compared to g p y ( g g ), p
adsorbents for liquid phase desulfurization.
- Proprietary and Business Sensitive - 5
Objectives
• To build a desulfurizer able to• To build a desulfurizer able to– Reduce total sulfur concentration to less than 3 ppmv– Provide a continuous run of 200 hours– Have a good low temperature performance for cold g p p
startup and transient operations– Small bed size: ~1 foot longSmall bed size: 1 foot long– Low pressure drop ca. 1-2 psi
- Proprietary and Business Sensitive - 6
Cyclic Arrangement and Transition OperationTransition Operation
Start with heating
5hours 4hours 1hour Transition
Time balance=
- Proprietary and Business Sensitive - 777
Reactor/Valve Sizes
Preferred desulfurization temperature: 400 CPreferred desulfurization temperature: 400 C
Preferred regeneration temperature: 600 C
Parameter Value ResultParticle size 0.8~1.4 mm Regn <5 hourReactor diameter 6” 60 cm/sBed length 12” L/D=2Pipe /valve size 2” 6 m/s
P=1.4 psi
Note:
The system works at 400 C during desulfurization and 600 C during regeneration.
Pipe /valve size 2 6 m/s
y g g gTherefore the valves are required to work at high temperature in the presence of oxygen during regeneration.
S lf i t 300
- Proprietary and Business Sensitive - 888
Sulfur input: 300 ppmv
Design Challenges
Reformates:Flow rate: 17 kg/hr .Temperature from reformer: 850 CReformate Composition:
High flow rate: Pressure DropHigh Temperature: Need heat exchanger
Component Concentration
CO 24.9%
g
High CO and CO concentrationCO2 10.2%
WATER 6.9%
H 25 0%
High CO and CO2 concentration,COS formation.CO2+H2S=COS+H2OCO+H S COS+HH2 25.0%
N2 33.0%
H2S 300 ppmv
CO+H2S=COS+H2
2 pp
Breakthrough Concentration: 2~3 ppmv Run time: 200 hours Regenerable
Small Reactor Good Low Temperature Performance for Cold
- Proprietary and Business Sensitive - 9
Pressure Drop: < 2 psi Startup and Transient Operations.
Desulfurization Performance COS Equilibrium AnalysesCOS Equilibrium Analyses
CO(g)+H2S(g)=COS(g)+H2(g) (slow homogeneous reaction)
(1) Experimental results suggest the COS formation via CO is slow the outlet
CO2(g)+H2S(g)=COS(g)+H2O(g) (fast heterogeneous reaction)
(1) Experimental results suggest the COS formation via CO is slow, the outlet COS concentration is about 6 ppmv at test conditions in a blank tube.
(2) COS formation via CO2 requires catalysts such as ZnS
(3) COS is difficult to be captured by ZnO sorbent. Hydrolysis is required
- Proprietary and Business Sensitive - 10
reformate composition: 25% CO, 25%H2, 10% CO2, 7% H2O and 33% N2.
Effects of CO and CO2
84.0
6
7
3.0
3.5
(ppm
)
FreshRegn 1
Need sorbents for COS removal or conversion 4
5
2.0
2.5
centration
0.1ppm
2
3
1.0
1.5
Sulfu
r Con
1.8 ppm1.7 ppm
add 25% CO
add 10% CO2
remove CO
0
1
0.0
0.5
0 50 100 150 200 250 300 350
0.2 ppmadd 25% CO
CO+H2S=COS+H2 K=0.0363 Ce=10.4 ppmv; CO2+H2S=COS+H2O K= 0.0029 Ce=1.2 ppmv
Time (min)
- Proprietary and Business Sensitive - 111111
Breakthrough curves of layered beds tested with 300 ppmv H2S-25% H2-25% CO-10% CO2-7% H2O-33% N2 at a face velocity=100 cm/s at 400 C. Bed length: 22 cm
Bed ConfigurationLayered Bed Design
Desulfurization
Layered Bed Design
• Low outlet sulfur concentration (as low as 0.3 ppmv)
• Less weight
Desulfurization
High capacity• Less weight• Short regeneration time• Low temperature function
Commercial ZnO bed (10 cm)
High capacityLong regn. timeHigh densityPoor contacting
p• Bed Configuration
– Down flow direction (in desulfurization)
(10 cm)
l it– (in desulfurization)– Diameter: 2.14 cm– Particle size: 0.8~1.4 mm
S d b
Supported ZnO sorbent bed (12 cm)
low capacityshort regn. timelow densityhigh contacting efficiency
– Supported sorbent: ZnO/SiO2 and supported Cu doped ZnO sorbent which has a better low temperature performance Regeneration
y
- Proprietary and Business Sensitive - 1212
performance. g
Layered- Bed Performance
(1) Allow multiple stop and resumestop and resume(2) Run time can be extended if necessarynecessary.
Desulfurization was carried out at 400 C in the presence of reformates containing 300ppmv H S 25% H 25% CO 10% CO 7%H O 33% N at a face velocity of 60
- Proprietary and Business Sensitive - 131313
300ppmv H2S-25% H2- 25% CO-10% CO2-7%H2O-33% N2 at a face velocity of 60 cm/s.
Cyclic Test(Layered Bed of ZnO-ZnO/SiO2)(Layered Bed of ZnO ZnO/SiO2)
2 50
2.00
2.50
pmv)
2 beds
1.50
entr
atio
n (p
p 2 beds
30 cycles/bed
5 hrs/cycle
0.50
1.00
ulfu
r con
ce
1st cycle
30th cycle
y
Total is 300 hours.
0.00
0.50
0 100 200 300 400 500 600
Su
0 100 200 300 400 500 600
Time (min.)
Desulfurization was carried out at 400 C in the presence of reformates
- Proprietary and Business Sensitive - 141414
pcontaining 300 ppmv H2S-25% H2- 25% CO-10% CO2-7%H2O-33% N2.
Reduced Regeneration Time
Sorbent can beSorbent can be regenerated in a shorter time;
Sorbent bed can beSorbent bed can be stop and resume multiple times during the runthe run.
Sorbent bed can provide a longer service time.
Tested with challenge gas containing 300 ppmv, 30% CO, 32% H2, 30% N2 and 8% H2O at a face velocity of 1.0 m/s at 400 C. The sorbent bed contains 56 g of 1 2 mm ZnO particles with a bed length of 10 cm and ZnO/SiO of 12 cm Spent
- Proprietary and Business Sensitive - 151515
1.2 mm ZnO particles with a bed length of 10 cm, and ZnO/SiO2 of 12 cm. Spent sorbent was regenerated in air-steam mixture containing ~14% O2 for 4 hours.
Low Temperature Performance
9.0
7.0
8.0
9.0pp
mv)
ZnO Bed Fresh
4 0
5.0
6.0
entr
atio
n (p Layered Bed Fresh
Layered Bed Regn 1Layered Bed Regn 2
2.0
3.0
4.0
ulfu
r Con
ce
0.0
1.0
0 50 100 150 200 250 300 350
Su
Desulfurization was carried out at 150 C in the presence of reformates
0 50 100 150 200 250 300 350
Time (min)
- Proprietary and Business Sensitive - 16
pcontaining 300 ppmv H2S-25% H2- 25% CO-10% CO2-7%H2O-33% N2.
Off-Site Regenerable Desulfurizer(Sulfur Cartridge)(Sulfur Cartridge)
• Single reactor provides a run time of 200 hours.g p
3 0
3.5
mv)
0-5 hr at 300 ppmv H2S
2 0
2.5
3.0
trat
ion
(pp 0 5 hr at 300 ppmv H2S
5-180hr at 2100 ppmv H2S180-200hr at 300 ppmv H2S
1.5
2.0
r Con
cent
0.5
1.0
utle
t Sul
fu
0.00 50 100 150 200 250
Ou
Equivalent Time (hour)
- Proprietary and Business Sensitive - 17
Desulfurization was carried out at 400 C in the presence of reformates containing 300ppmv H2S-25% H2- 25% CO-10% CO2-7%H2O-33% N2 at a face velocity of 60 cm/s.
Desulfurizer ConstructionSorbent Loaded for DesulfurizerSorbent Loaded for Desulfurizer
- Proprietary and Business Sensitive - 1818
Conclusion
• The layered bed made of commercial ZnO andThe layered bed made of commercial ZnO and supported ZnO based sorbent demonstrated a wide operational temperature window (150~400 C).
• The layered bed are highly regenerable. It can be regenerated for 30 cycle without significant changes in desulfurization performance.
• The designed desulfurizer can provide a continuous run with regeneration or 200 hours run as a sulfur cartridge.
- Proprietary and Business Sensitive - 19
AcknowledgementsAcknowledgements
Award #: W56HZV-07-C-0577
- Proprietary and Business Sensitive - 20202020
Thank you for your attention
Questions?Q
- Proprietary and Business Sensitive - 21212121