Increasing the Carbon
Capture Efficiency of the
Ca/Cu looping process with
advanced process schemes
M. Martinia, I. Martinezb, F. Galluccia, M. C. Romanob,
M. van Sint Annalanda
aChemical
Process Intensification, Chemical Engineering and Chemistry, Eindhoven
University of Technology, Eindhoven, The Netherlands
bEnergy
Department, Politecnico di Milano, Milano, Italy
Department of Chemical Engineering and Chemistry (SPI)
Outline
2
•
Introduction: Ca-Cu process
•
Process scheme
•
Sensitivity analysis
•
Dual bed with gas intercooling scheme
•
Conclusions and future steps
Department of Chemical Engineering and Chemistry (SPI)
Introduction
Ca – Cu looping process
SER based process. Heat required for CaCO3 calcination supplied through CuO reduction
SER stage
Produced at high
pressure
Carried out at high
pressure to limit
calcination
CaCO3 Calcination/
Reduction of CuO
Cu oxidation
Carried out at low pressure to
avoid high calcination
temperature
12-5-2017
3
Department of Chemical Engineering and Chemistry (SPI)
Process scheme
To avoid irregular
profiles in the bed
To avoid carbon
deposition
Conditions to avoid hydration in step A: P = 20 bar, T = 700 ⁰C
CCE = 73%
4
Department of Chemical Engineering and Chemistry (SPI)
Profiles in the bed
T, °C
t = 1000
sec
250
500
0 secsec
950
900
850
800
750
700
650
600
550
500
0
2
4
6
Axial position, m
8
10
0
2
4
6
Axial position, m
8
10
0
2
4
6
Axial position, m
8
10
1.2
XCaO,active
1
0.8
0.6
0.4
0.2
inlet
5
700
yCH4
0.2148
yH2
0.0733
0.8
0.7
yg[CH4]
yg[CO2]
Molar fraction
Tgas, °C
0
0.6
0.5
yCO
0.0003
yCO2
0.0278
yg[H2O]
yH2O
0.6818
yg[CO]
0.2
0.1
yN2
0.0020
yg[N2]
yg[H2]
0.4
0.3
0
Department of Chemical Engineering and Chemistry (SPI)
Sensitivity analysis
•
It was carried out only on step A
•
Parameters changed:
– S/C ratio: 3 - 4 - 5
– Pressure: between 15 bar and 30 bar
– Inlet Temperature: between 500 ⁰C and 700 ⁰ C
– Initial bed temperature: 650 ⁰ C and 800 ⁰ C
7
Results of the sensitivity analysis
•
Inlet gas coming from adiabatic pre-reforming at 490 ⁰C
Tin = Tbed =700 ⁰C
- Tin = Tbed = 700 °C
-
SC-ratio = 3
- P = 25 bar
100
100
90
90
80
80
70
70
60
60
CCE
CH4 conversion
50
CO conversion
CO2 conversion
40
10
15
20
25
Pressure (bar)
30
50
40
35
Carbon Capture Efficiency (%)
-
100
100
90
90
80
80
70
70
CCE
CH4 conversion
60
Conversion (%)
Effect of SC-ratio:
Conversion (%)
Carbon Capture Efficiency (%)
Effect of pressure:
60
CO conversion
CO2 conversion
50
50
2
3
4
5
6
S/C (-)
CCE = 76% with S/C = 5
8
Results of the sensitivity analysis
- Tbed = 700 °C
-
SC-ratio = 5
- SC-ratio = 5
-
P = 25bar
- P = 25 bar
100
100
90
90
80
80
70
60
70
CCE
CH4 conversion
60
CO conversion
CO2 conversion
50
600
650
700
750
800
50
850
Carbon Capture Efficiency (%)
Tin = 700 ⁰C
100
100
90
90
80
80
CCE
CH4 conversion
70
CO conversion
CO2 conversion
60
450
Initial bed temperature (°C)
500
550
600
650
Inlet temperature (°C)
CCE = 80%
with S/C = 5, Tin = 500 °C and Tbed = 700 °C
9
70
700
60
750
Conversion (%)
Effect of inlet temperature:
-
Conversion (%)
Carbon Capture Efficiency (%)
Effect of initial bed temperature:
Dual bed with gas-intercooling
Step A
Tbed,in = 700 ⁰C
Pin = 25 bar
Inlet gas from stage A’
T ≈ 850 ⁰C
Low carbon content
StepA’
Tbed,in = 700 ⁰C
Tgas,in = 500 °C
Pin = 25.2 bar
Inlet gas from adiabatic
pre-reformer at 490 ⁰C (S/C=4)
Step B
Step B’
Tbed,in = 500 ⁰C
Tgas,in = 340 ⁰C
Pin = 21 bar
3 % O2 in the inlet
Tbed,in = 340 ⁰C
Tgas,in ≈ 700 ⁰C
P = 19 bar
Step C
Tbed,in ≈ 700 ⁰C
Tgas,in = 700 ⁰C
Inlet gas from heated prereformer at 700°C (S/C=1)
P = 1 bar
10
Dual bed with gas-intercooling
850
750
T, °C
Step A
0 secsec
380
t = 760
650
550
Step A
A’
t = 360
0760
secsec
450
0
2
4
6
Axial position, m
8
10
0
2
4
6
Axial position, m
8
10
0
2
4
66
Axial position, m
Axial position, m
88
1
XCaO, active
0.8
11
0.6
0.4
In A
In A’
0.2
T, °C
700.0
500.0
0
yCH4
1.05%
14.02%
yCO2
1.60%
2.20%
yH2
48.29%
6.25%
yH2O
47.03%
77.37%
yCO
1.92%
0.02%
yO2
0.00%
0.00%
yN2
0.11%
0.13%
yg[CH4]
yg[CH4]
yg[CO2]
yg[CO2]
yg[H2]
yg[H2]
yg[H2O]
yg[H2O]
yg[CO]
yg[CO]
yg[N2]
yg[N2]
molar
fraction
Molarfraction
0.6
0.8
0.7
0.5
0.6
0.4
0.5
0.3
0.4
0.3
0.2
0.2
0.1
0.1
0
10
10
Dual bed with gas-intercooling
Temperature and composition of the inlet and outlet gas streams
A
A'
B
B'
In
Out
In
Out
In
Out
In
Out
In
Out
T, °C
700.0
744.9
500.0
835.6
340.0
699.4
699.0
527.1
700.0
703.6
yCH4
1.05%
1.11%
14.02%
1.07%
0.00%
0.00%
0.00%
0.00%
11.00%
0.01%
yCO2
1.60%
0.27%
2.20%
1.66%
1.85%
2.05%
2.20%
1.93%
3.80%
46.03%
yH2
48.29%
51.08%
6.25%
48.06%
0.00%
0.00%
0.00%
0.00%
60.00%
1.22%
yH2O
47.03%
47.17%
77.37%
47.11%
0.00%
0.00%
0.00%
0.00%
8.00%
51.91%
yCO
1.92%
0.26%
0.02%
1.99%
0.00%
0.00%
0.00%
0.00%
16.60%
0.72%
yO2
0.00%
0.00%
0.00%
0.00%
3.00%
0.02%
0.00%
0.00%
0.00%
0.00%
yN2
0.11%
0.11%
0.13%
0.11%
95.15%
97.93%
97.80%
98.07%
0.20%
0.10%
Carbon capture efficiency: 87%
12
C
Conclusions and future steps
• Conclusion:
– From sensitivity analysis:
• Best case: S/C = 5, Tin = 500 °C, Tbed = 700 °C, 25bar
– Changes in configuration:
• Dual bed with gas intercooling in step A (CCE = 87%)
• Future work:
– Experimental investigation of hydration of CaO at high
pressure
– Different process configurations
13
Department of Chemical Engineering and Chemistry (SPI)
Acknowledgements
The ASCENT project as part of the European Union’s Seventh Framework Programme (FP7/20072013) under grant agreement nº 608512.
Note: "The present publication reflects only the authors’ views and the European Union is not liable for
any use that may be made of the information contained therein”.
Thank you
for your attention
Michela Martini: [email protected]
14
Department of Chemical Engineering and Chemistry (SPI)