ECRA-Cemcap Workshop Chilled ammonia process for CO2 capture · Technology for a better society 5...
Transcript of ECRA-Cemcap Workshop Chilled ammonia process for CO2 capture · Technology for a better society 5...
Technology for a better society
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ECRA-Cemcap Workshop
José-Francisco Pérez-Calvo
Daniel Sutter
Matteo Gazzani
Marco Mazzotti
Chilled ammonia process for CO2 capture
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Technology for a better society
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1. Introduction to Chilled Ammonia Capture Process (CAP)
2. Research topics in the CAP
3. Criticalities for CAP application to cement plant conditions
Presentation layout
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The Chilled Ammonia Process
1 Flue gas cooling
2 CO2 removal
3 NH3 slip
abatement
4 CO2
purification
Cleaned fluegas CO2
Fluegas
Post-combustion CO2 capture
Aqueous ammonia as solvent
Main advantages:
globally available, low cost
no toxic degradation products
highly competitive energy penalty
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The Chilled Ammonia Process
Flue gas in
CO2 depleted flue gas
Absorber pumparound
CO2 lean solution
CO2 rich solution
CO2
CO2 storage
Cooled flue gas
CO2
Absorber CO2 Desorber
Flue gas to the stack NH3 water wash
(NH3 + CO2+H2O) to CO2 capture section
Makeup H2O
DCC
NH3 slip
abatement
CO2 removal
Fluegas
cooling
CO2
purification
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Hype cycle for NH3-based CO2 capture
[7] Bollinger et al. Alstom Technical Report, Paper No. 72 [8] Darde et al. Int J Greenh Gas Control, 10 (2012) 74-87 [9] Black et al. (2013) Patent No. US 2013/0028807 A1 [10] Darde et al. Ind Eng Chem Res. 49 (2010) 12663-12674) [11] Que and Chen. Ind Eng Chem Res. 50 (2011) 11406-11421 [12] Baburao et al. Presentation at TCCS-8, Trondheim, Norway
[1] Bai and Yeh. Ind Eng Chem Sc. 36 (1997) 2490-2493 [2] Bai and Yeh. Sci Total Environ. 228 (1999) 121-133 [3] Gal. (2006) Patent No. WO2006/022885A1 [4] Mathias et al. Energy Procedia 1 (2009) 1227-1234 [5] Mathias et al. Int J Greenh Gas Con 4 (2010) 174-179 [6] Yu et al. Chem Eng Res and Des. 89 (2011) 1204-1215
• understand • control • Exploit solid formation in the CAP.
• new process synthesis • optimization • piloting
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Features of an efficient Chilled Ammonia Process
OPTIMAL CAP plant
Low chilling
duty
Low reboiler
duty
Avoiding solid
formation
Low ammonia
slip
High absorption
mass transfer
Energy and
environmental
performance
Plant operation
and design
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CAP research topics
Thermo- dynamics
Kinetics Process
Synthesis Process
Optimization Process
Integration
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Thermo- dynamics
Kinetics Process
Synthesis Process
Optimization Process
Integration
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Understanding the system thermodynamics
VLE
SLE
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Understanding the system thermodynamics
adapted from: Darde et al., Ind Eng Chem Res 49 (2010) 12663-74
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Phase diagram construction
wt. frac.
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Phase diagram construction
10°C
1 bar
Thermodynamic model: Thomsen and Rasmussen. Chem Eng Sci. 54 (1999)1787-1802 Darde et al., Ind Eng Chem Res. 49 (2010) 12663-74 Solid properties: Jänecke, Z Elektrochem. 35 (1929) 9:716-28
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1 bar
Phase diagram construction
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1 bar
Phase diagram construction
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1 bar
Phase diagram construction
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1 bar
Phase diagram construction
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The Chilled Ammonia Process
Flue gas in
CO2 depleted flue gas
Absorber pumparound
CO2 lean solution
CO2 rich solution
CO2
CO2 storage
Cooled flue gas
CO2
Absorber CO2 Desorber
Flue gas to the stack NH3 water wash
(NH3 + CO2+H2O) to CO2 capture section
Makeup H2O
DCC
NH3 slip
abatement
CO2 removal
Fluegas
cooling
CO2
purification
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CO2 depleted flue gas
Pump- around
CO2-lean solution
CO2-rich solution
Cooled flue gas
CO2 absorber
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CO2 depleted flue gas
Pump- around
CO2-lean solution
CO2-rich solution
Cooled flue gas
CO2 absorber
Feed
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Thermo- dynamics
Kinetics Process
Synthesis Process
Optimization Process
Integration
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Kinetics – equilibrium and rate-controlled reactions
(1) Self-ionization of water
(2) Dissociation of bicarbonate
(3) Protonation of ammonia
(4) Bicarbonate ion formation
𝐇𝟐𝐎𝐊𝟏 𝐎𝐇− + 𝐇+
𝐇𝐂𝐎𝟑−𝐊𝟐 𝐂𝐎𝟑
𝟐− +𝐇+
𝐍𝐇𝟑 +𝐇𝟐𝐎𝐊𝟑 𝐍𝐇𝟒
+ + 𝐎𝐇−
𝐂𝐎𝟐 + 𝐎𝐇−𝐤𝟒,𝐤−𝟒,𝐊𝟒
𝐇𝐂𝐎𝟑−
(5) Carbamate ion formation
Equ
ilib
riu
m
rea
ctio
ns
Dif
fusi
on
an
d r
ate
co
ntr
oll
ed
re
act
ion
s
𝐂𝐎𝟐 + 𝐍𝐇𝟑𝐤𝟓,𝐤−𝟓,𝐊𝟓
𝐍𝐇𝟐𝐂𝐎𝐎− +𝐇+
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Kinetics – chemical reaction mechanisms
Bicarbonate ion formation
carbonic acid dissociation CO2 + H2O HCO3
− + H+ negligible contribution for pH>8 [4]
reaction with hydroxide ion CO2 + OH− HCO3
−
Carbamate ion formation
Zwitterion mechanism[5,6]
Zwitterion formation CO2 + NH3 NH3
+COO−
deprotonation NH3+COO− + B
NH2COO
− + BH+ often considered non-rate-limiting[1-3]
Termolecular mechanism[7,8] CO2 + NH3 + B NH2COO
− + B
Elementary reactions mechanism[9]
CO2 + NH3 NH2COO
− + H+
[1] Pinsent et al. Trans Faraday Soc. 52 (1956) 1594-1598. [2] Pinsent et al. Trans Faraday Soc. 52 (1956) 1512-1520. [3] Puxty et al. Chem Eng Sci. 65 (2009) 915-922. [4] Blauwhoff et al., Chem Eng Sci. 39 (1984) 207-225. [5] Caplow. J Am Chem Soc. 90 (1968) 6795-6803.
[6] Danckwerts. Chem Eng Sci. 34 (1979) 443-446. [7] Crooks and Donellan. J Chem Soc Perkin Trans II. 4 (1989) 331. [8] da Silva and Svendsen. Ind Eng Chem Res. 43 (2004) 3413-3418. [9] Wang et al. J Phys Chem. 115 (2011) 6405-6412.
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Thermo- dynamics
Kinetics Process
Synthesis Process
Optimization Process
Integration
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Integrate solid formation into a next generation CAP
• Solid formation in the crystallizer
• No solids in the columns
The chilled ammonia process with solid formation
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Cooled flue gas
CO2 depleted flue gas
Pumparound CO2 lean solution
CO2 rich solution
CO2
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The chilled ammonia process with solids formation
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CO2
Absorber CO2 Desorber
NH3 water wash
Direct contact cooler
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0 0.5 1
Co
lum
n s
tage
s
Solubility index
Absorber profile: standard vs crystallizer CAP
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standard CAP crystallizer CAP
CO2 depleted flue gas
Pumparound
CO2 lean solution
CO2 rich solution
Cooled flue gas
Cooled flue gas
CO2 depleted flue gas
Pumparound
CO2 lean solution
CO2 rich solution
Crystallizer CAP
Standard CAP
• Lower working temperature • Better ammonia slip control
bottom
top
• Higher solubility index • Higher CO2 loading (lower flow rate)
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Thermo- dynamics
Kinetics Process
Synthesis Process
Optimization Process
Integration
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Definition of the CAP operating conditions
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Process optimization
First Stage
Exploit the user sensitivity and knowledge of the process by visualizing the conditions on a CO2-NH3-H2O ternary phase diagram
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Definition of the CAP operating conditions
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Process optimization
First Stage Second Stage
Exploit the user sensitivity and knowledge of the process by visualizing the conditions on a CO2-NH3-H2O ternary phase diagram
Optimization of the CAP in a limited feasible region of the operating variables
MATLAB overarching structure
Input parameters: • NH3 fraction in water • CO2 loading lean stream • Absorber loading • L/G • Reboiler Duty
Sensitivity analysis - CO2
capture section
Minimized function: • Specific reboiler duty Input variables: • L/G • Reboiler duty Constraints: • NH3 removal • CO2 capture
Rigorous optimization -NH3 removal section
Final operating conditions
Matlab+Aspen
Aspen
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ECRA-Cemcap Workshop
Criticalities for CAP application to cement plant conditions
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Outline
Increment in the content of CO2 in the flue gas
Power plant 2 – 16%mol
Cement plant up to 30%mol
Modifications of absorber conditions
Cement-like CO2 content leads to different operating conditions of
CAP and/or process modifications
To reach 90% of CO2 recovery in the flue gas from the
cement plant:
(i) Increase the liquid-to-vapor flowrate
(ii) Increase the ammonia content in the CO2-lean stream
and/or
(iii) Decrease the CO2 loading of the CO2-lean solution
Multiple combinations:
(i) L/G
(ii) Pumparound/Rich
(iii) [NH3]CO2-lean
(iv) (CO2 load)CO2-lean
Flue
gas in
CO2
depleted
flue gas
Absorber
pumparound
CO2
lean
solution
CO2 rich solution
CO2
Absorber
L
G
Pumparound
Rich
[NH3]
CO2 load
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Absorber simulations – Exemplary cases
Flue
gas in
CO2
depleted
flue gas
Absorber
pumparound
CO2 lean
solution
CO2 rich solution
Cooled flue
gas
CO2
Absorber
Makeup
H2O
DCC
3
1
2
4
5
6
yair = 0.84
yCO2 = 0.16
yH2O = 0
T = 140°C
Power Plant – Base case
Cement Plant cases
yair = 0.70
yCO2 = 0.30
yH2O = 0
T = 110°C
~ 90% CO2 recovery
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Absorber simulations – Exemplary cases
2 4 6 8 10 12
L/G (wt)
0.0 0.1 0.2 0.3 0.4
V-phase comp (mass frac)
CO2
NH3
1
6
11
16
21
26
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10 15 20 25 30 35 40 45 50 55
Stag
eTemperature (°C)
Power Plant
Two differenciated regions in the
absorber separated by the CO2-
lean stream:
(i) NH3-uptake
(ii) CO2-uptake
Inlet flue gas yCO2 = 0.16
CO2-lean stream CO2load = 0.35 molCO2/molNH3
[NH3] = 14 %wt (binary)
Absorption process L/G = 3.7 kg/kg
Pumparound/Rich = 0.36
CO2 capture ≈ 90 %
NH3 slip ≈ 10000 ppmv
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Modelling Thermodynamic
model
Simplified kinetics
Power Plant
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Modelling Thermodynamic
model
Process simulation RATE-BASED
Simplified kinetics
Pilot Plant Tests 2 – 16 %mol CO2
Power Plant
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Modelling
Process simulation EQUILIBRIUM-BASED Murphree efficiencies
Power Plant
Process Integration Process simulation
RATE-BASED
Murphree efficiencies
Power Plant
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Modelling
Process simulation EQUILIBRIUM-BASED Murphree efficiencies
Cement Plant
Process simulation RATE-BASED
Power Plant
Murphree efficiencies
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Modelling
Murphree efficiencies???
Process Integration
Thermodynamic model
Process simulation RATE-BASED
Simplified kinetics
Pilot Plant Tests 2 – 16 %mol CO2
Cement Plant
Power Plant
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CEMCAP approach
Murphree efficiencies
Thermodynamic model
Modelling & Simulation RATE-BASED
Extended kinetics
Pilot Plant Tests up to 30 %mol CO2
Process Integration Process simulation
EQUILIBRIUM-BASED Murphree efficiencies
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Acknowledgements
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no 641185
This work was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 15.0160
www.sintef.no/cemcap
Twitter: @CEMCAP_CO2