Date post: | 14-Jan-2016 |
Category: |
Documents |
Upload: | sherman-stevens |
View: | 212 times |
Download: | 0 times |
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
1
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Politecnico di MilanoDipartimento di Energia
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4 C
on
ve
rsio
n (
%)
Time (s)
Research activity from Nov 08 to May 09
at Laboratory of Catalyis and Catalytic Processes
Gianpiero Groppi
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
2
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Outline
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
C
H4
Co
nve
rsio
n (
%)
Time (s)
• Development of new catalysts formulations
– Pd only catalysts: effect of the support
– Pt-Pd catalysts: Effect of Pt/Pd ratio
• Ecocat reference catalyst
– Tests on washcoat powders
– Monolith sample
– S-poisoning
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
3
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Outline
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4 C
on
ve
rsio
n (
%)
Time (s)
• Pd only catalysts: effect of the support
• Pt-Pd catalysts: Effect of Pt/Pd ratio
• Ecocat reference catalyst– Tests on washcoat powders– Monolith sample– S-poisoning
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
4
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Effect of the support: preparation and characterization
Al2O3 and ZrO2: Tc = 950°C for 10 h
Ce and La added as nitrate, then calcined (Tc = 950°C for 10 h)
dry impregnation with Pd(NO3)2 solution, Tc = 600°C for 10 h
Pd load% (w/w)
SupportBET : SSA
[m2/g]
Vp
[cm3/g]XRD
H2 Chem.
D % dp [nm]
2Al2O3
SASOL PURALOX SBA 140117 0.49
θ ( γ
traces)21 6
2 12.5% w/w CeO2 – Al2O3 70 0.28
θ ( γ
traces)CeO2
12 9
2 3% w/w La2O3 – Al2O3 100 0.49
θ ( γ
traces)10 11
2ZrO2
MELCAT – Chemicals F20 936/01
19 0.17 Monocline 5 25
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
5
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Test on powder catalysts: apparatus and procedures
LEAN COMBUSTION : CH4 0.5%; O2 4%; H2O 1%; He/Ar; 93.5%; (30 min).
REDUCING PULSE: CH4 0.5%; H2O 1% ;He/Ar 97.5%; (120 s)
PURGE: He 95%, 5%N2 ( 30s )
T: 350°C, GHSV = 150.000 Ncm3/gcat/h, P = 1 atm.
quartzwool Powder
catalyst
thermocoupleinternal
gas in
Gas out
Micro-reactor
0
Reaction
30 min
He
O2
H2O
CH4- Ar
ReactionPurge PurgeReducing
pulse
A.
U.
Time
2 min
30min
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
6
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Conditioning by redox cycles
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nver
sion
%
Time (s)
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nver
sion
%
Time (s)
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nve
rsio
n %
Time (s)
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nve
rsio
n %
Time (s)
2% Pd/Al2O32% Pd/CeO2 - Al2O3
2% Pd/La2O3 - Al2O32% Pd/ZrO2
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
7
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Lean combustion behaviour after conditioning
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
2% Pd/Al2O3
0 1000 2000 3000 4000 50000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nver
sion
(%
)
Time (s)
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (
%)
Time (s)
2% Pd/CeO2 - Al2O3
2% Pd/La2O3 - Al2O32% Pd/ZrO2
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
8
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
TOF before and after conditioning
0 1 2 3 4 5 6 7 8 9 100
10
20
30
40
50
60
70
80
90
100
2% Pd/Al2O3 2% Pd/Al2O3-CeO2 2% Pd/Al2O3-La2O3 2% Pd/ZrO2
CH
4 co
nver
sion
%
Red-Ox cycle
Isothermal PFR
T = 350°C
PCH4 = 0.5 kPa
PH2O = 1.1 kPa
r = k . PCH4 . PH2O-1
SupportAs prepared
TOF [s-1]
Conditioned
TOF [s-1]KC/KAP
Al2O30.07 0.38 5
ZrO20.36 0.8 2
CeO2 – Al2O30.09 0.52 5
La2O3 – Al2O30.07 0.45 6
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
9
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Outline
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4 C
on
ve
rsio
n (
%)
Time (s)
• Pd only catalysts: effect of the support
• Pt-Pd catalysts: Effect of Pt/Pd ratio
• Ecocat reference catalyst– Tests on washcoat powders– Monolith sample– S-poisoning
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
10
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Characterization of bimetallic Pt-Pd systems
nominal Pt/Pd
Atomic ratio
Actual Pd e Pt
Load (% w/w)
(AAS)
actual Pt/Pd
Atomic ratio
dp XRD
as prepared
(nm)
Pd dispersion
(H2 Chemisorption)
0Pt: 0.00
0PdO: 5
21%Pd: 2.14 Pt: n.d.
0.10Pt: 0.56
0.12PdO: 8
13%Pd: 2.50 Pt: n.d.
0.25Pt: 1.50
0.33PdO: 7
12%Pd: 2.50 Pt: n.d.
1Pt: 4.36
1.22PdO: 6
15%Pd: 1.95 Pt: 19
Constant nominal Pd load: 2% w/w
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
11
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Activity of fresh catalysts
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4Con
vers
ion
(%
)
Time (s)
Pt/Pd = 0 Pt/Pd = 0.10 Pt/Pd = 0.25 Pt/Pd = 1
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
12
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Conditioning by redox cycles
0 500 1000 1500 2000 25000
10
2030
40
50
60
7080
90
100
cycle 1cycle 2
cycles 3-7
CH
4 co
nve
rsio
n(%
)
Time (s)
initial activity
Pt/Pd = 0
0 500 1000 1500 2000 25000
10
20
30
40
50
60
70
80
90
100cycle 4-11
cycle 3
cycle 2
CH
4 co
nve
rsio
n (
%)
Time (s)
initial activity
cycle 1
Pt/Pd = 0,10
0 500 1000 1500 2000 25000
10
20
30
40
50
60
70
80
90
100Pt/Pd = 0,25
cycles 7-18
cycle 5-6cycles 2-4cycle 1
initial activity
CH
4 C
on
vers
ion
(%
)
Time (s)0 500 1000 1500 2000 2500
0102030405060708090
100
CH
4 con
vers
ion(
%)
Time (s)
initial activity
cycles 1-6
Pt/Pd = 1
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
13
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Pt-Pd catalysts: Reactivation behaviour
0 30 60 90 120 150 180 210 240 270 3000,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
Pt/Pd-0,25
Pt/Pd-0,10
CH
4/C
H4m
ax (3
50
°C)
Time (s)
Pt/Pd-0
0 50 100 150 200 250 300 900 1200 1500 18000,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
Pt/Pd = 0,25
Pt/Pd = 0,10
Ext
en
t o
f P
d o
xid
atio
n
Time (s)
Pt/Pd = 0
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
14
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Pt-Pd catalysts: TPO measurements
100 200 300 400 500 600 700 800 900 1000
Pt/Pd = 0
Pt/Pd = 0,10
Pt/Pd= 0,25
O2 (
a.u
.)
T (°C)
Pd/Pt = 1
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
15
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Outline
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4 C
on
ve
rsio
n (
%)
Time (s)
• Pd only catalysts: effect of the support
• Pt-Pd catalysts: Effect of Pt/Pd ratio
• Ecocat reference catalyst– Tests on washcoat powders– Monolith sample– S-poisoning
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
16
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Tests on washcoat powders
0 300 600 900 1200 1500 18000
10
20
30
40
50
60
70
80
90
100
CH
4 co
nver
sion
%
Time (s)0 2 4 6 8 10
0
10
20
30
40
50
60
70
80
90
100
Ecocat 2% Pd/Al2O3 2% Pd/ZrO2 2% Pd/Al2O3-CeO2 2% Pd/Al2O3-La2O3
CH
4 c
on
vers
ion
%Red-Ox cycle
Kccond/Kcas received =2
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
17
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Tests on washcoat powders: S poisoning
0 1 2 3 4 5 6
0
2
4
6
8
10
12
14
16
Outlet SO2
SO
2 (p
pm)
Time (h)
Inlet SO2
T=400°C; WHSV=1.8E+5 Ncm3/g/hCH4=6000 ppm; SO2=15 ppm; O2=5.2%; H2O=3.5%; N2 to balance
0 1 2 3 4 5 60
20
40
60
80
100
0,000
0,002
0,004
0,006
0,008
0,010
0,012
0,014
0,016
0,018
0,020
CH
4 C
onve
rsio
n [%
]
Time [h]
Sads (g
S /gw
ash )
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
18
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
36 cm
15.2 cm15.2 cm
1.63 cm
2.5 cm
Test on monolith samples: Experimental apparatus
6x6 channels
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
19
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Test on monolith samples: preliminary results
200 250 300 350 400 450 500 550 600 650 7000
20
40
60
80
100
CH
4 co
nver
sion
[%]
Temperature [°C]
-5 0 5 10 15 20 25250
300
350
400
450
500
550
600
650
700
Ga
s te
mp
era
ture
[°C
]
Monolith length [mm]
Flow
Conversion
Q = 1215 Ncm3/minGHSV = 50000 h-1 (monolith volume)
Temperature profiles
Feed: 3% O2; 0.7% CH4; 0% H2O N2 to balance 0 20 40 60 80 100
0
10
20
30
40
50
60
70
80
Tm
ax
CH4conversion %
cfr Tad=180°C
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
20
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Powder 0.06 g WHSV=1.5E+5 Ncm3/g/h
Ground monolith 0.009 g* WHSW=1.0 E+6 Ncm3/g/h
Monolith 0.147 g* WHSW=5.0 E+5 Ncm3/g/h*hp: 15% w/w washcoat
Test on monolith samples: preliminary analysis
200 250 300 350 400 450 500 550 600 650 700
0
20
40
60
80
100
Con
vers
ion
[%]
Temperature [°C]
Monolith 0% H2O
Ground monolith 1% H2O
Powder 1% H2O
422, OHadsH
OHOHads
CH
Pk
Pkr
22,
41
1
285.5400@1 ECk
302.1400@2, ECk OHads
34Eact kJ
kJ
moles/atm/s
.atm-1
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
21
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Annular ReactorAnnular Reactor
• Laminar flow negligible pressure drops
• High GHSV 106 – 107 Nl/Kgcat/h
distance from thermodynamic constraints
• Catalyst layer thickness 10 – 20m
• Small annular gap 0.5 mm
• Regular structured geometry
• Efficient heat dissipation by radiation
• Thermal equilibrium across the section of the ceramic tube
INLET
OUTLETTC
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
22
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Conclusions - 1
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4
Co
nve
rsio
n (
%)
Time (s)
• Marked activation of Pd-only catalysts upon reduction/re-oxidation cycles
• Limited effect of the support on the overall catalytic activity of Pd-only catalyst
– Control of Pd dispersion (Al2O3>ZrO2)
– Slight decrease of TOF on increasing dispersion
• Addition of Pt is beneficial on the activity of the as prepared catalysts but
depresses reactivation upon reduction/re-oxidation cycles
• On increasing Pt/Pd ratio oxidation of Pd is progressively inhibited (alloying or
decoration/passivation)
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
23
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Conclusions-2
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4
Co
nve
rsio
n (
%)
Time (s)
• On Ecocat reference sample redox cycles provides limited
enhancement of activity
• Ecocat reference sample (washcoat powders) shows a similar activity
to Al2O3 supported Pd catalysts
– Higher Pd load, lower dispersion?
• Treatment in SO2 containing, lean combustion atmosphere results in
marked catalyst deactivation (about 1/10 at 15 mgS/gwash)
• Preliminary tests on monolith samples show comparable activity with
powder catalysts. Significant temperature gradients are observed
along the catalyst bed which might bias kinetic investigation.
INGAS 6 month meeting, Prague, 25-26 May 2009INGAS 6 month meeting, Prague, 25-26 May 2009
INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain
24
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH
4 C
onve
rsio
n (%
)
Time (s)
Future activities
0 1000 2000 3000 4000 5000 60000
10
20
30
40
50
60
70
80
90
100
CH 4 C
on
ve
rsio
n (
%)
Time (s)
• Kinetic studies on Ecocat reference catalyst (what reactor?)
• Testing of materials under project boundary conditions
• Studies on S-poisoning and regeneration treatments
• Studies on hydrothermal stability
• Further characterization studies, particularly of bimetallic system (to be discussed with ICSC-PAS)