pilot / lab scale study of co2 separation · 2 – 200 l/h n 2 - 300 l/h fluid flow 2~5 l/h...
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Pilot / lab scale study of CO2 separation
with ionic liquid blending
Dawei Shang, Xiangping Zhang, Suojiang Zhang
Institute of Process Engineering, Chinese Academy of Sciences
12 June-14 June, 2017
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Global warming and CCS
Glaciers Melting www.qiankungold.com
Absorption
Membrane
PSA、TSA
CCS technologies
Chemical absorbents
Amino solutions
Physical absorbents
NHD
Ionic liquids
High gas solubility
Good thermal stability
Low heat capacity
Negligible vapor pressure
2
Molten Salts
NaCl (m.p. 800oC), LiCl-KCl (m.p. 355oC), NaCl-AlCl3 (m.p. 107oC)
Ionic Liquids
Liquid at RT
Nonvolatile
Designable
Medium / Catalyst
N N R
+
PF-
R
1
BF4-
Ionic Liquids: A New Generation of Medium
3
0.00
0.05
0.10
0.15
0.20
2005
2005
2007
2009
2012
[Bmim][PF6]
[TMG][L] [HEA][A]
[P4443][Gly]
[DAIL][Br]
Chemical absorption
(30O
C,0.1MPa)
(25O
C,0.1MPa)
(35O
C,2.24MPa)
(40O
C,1.56MPa) (40
O
C,1.31MPa)
[E1Py][Tf2N]
2014
(40O
C,1.93MPa)
Physical absorption
So
lub
ilit
y (
gC
O2/g
IL
)
Energy Environ Science, 2012, 5: 6668; J Chem Eng Data, 2010, 55: 3513; Chem Eng J, 2014, 251: 248;
Fluid Phase Equilibr, 2010, 297: 34; Ind Eng Chem Res, 2013, 52: 5835; Fluid Phase Equilibr, 2014; 365:80;
Ind Eng Chem Res, 2014, 53: 16832; RSC Adv, 2015, 5: 2470 ; Applied Energy, 2015, 154:771.
CCS with ionic liquids
4
E-17
冷却器
净化气分离器
净化气
变换气闪蒸气
闪蒸灌
半贫液泵
贫液泵 冷却器
溶液换热器
煮沸器
蒸汽
气提再生塔
再生冷却器
再生气
再生气分离灌两级解吸塔
新鲜溶剂
补充离子液体
溶剂泵
两段吸收塔
Molecular Unit operation System Cluster
Scale up of CO2 separation with ILs
Scale up for the CCS process of ILs
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Mass transfer coefficient depends on various factors,
including viscosities and ILs’ structures
Solvents Viscosity (mPa S)
kL×105 m/s
[omim][BF4] 136.0 1.51
[bmim][BF4] 56.4 1.36
[bmim][DCA] 18.2 1.04
[bmim][NO3] 89.9 0.89
H2O 1.0 2.07
2
2 2
0
0ln
1 1
CO
L
CO CO
Pk at
P P
AIChE J, 2014, 60: 2929; Ind Eng Chem Res, 2014, 53: 428
Mass transfer of gases in ILs
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ILs Water ILs Water
Bubble behavior in ILs and water
Different bubble behaviors in water and ILs 7
FCCS
CFD method
Models modifications
Chem Eng Sci, 2015, 135: 76
Chem Eng J, 2012, 209: 607;
Ind Eng Chem Res, 2014, 53: 428
CO2 concentration
Dynamic process of CO2 absorption
[omim][BF4] [bmim][NO3] [bmim][BF4] 95%wt[bmim][BF4]
Models of the bubble behavior
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Process simulation and cost estimation
Experimental and calculated heat capacities of ILs Effect of αlean on the regeneration thermal energy
requirement of MEA and IL-based processes
Ind. Eng. Chem. Res. 2014, 53: 11805−11817
Modified process flow diagram for CO2 capture with
ILs-amine blending
[Bpy][BF4]- MEA process can save
about 15% regeneration heat duty
compared to the conventional MEA
process.
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CO2 separation from syngas
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Continuous apparatus for CO2 capture
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CO2 N2
Absorption
tower
Rich
solvents
Lean
solvents
CO2 detector
Desorption
tower
Continuous apparatus for CO2 capture
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Solvent
27% MDEA
3% PZ
(10% Ionic liquid)
Pressure ~ 10 Bar
Gas flow CO2 – 200 L/h
N2 - 300 L/h
Fluid flow 2~5 L/h
Parameters and part results
Component of the absorbent and the operating parameters
Amine solution
Pressure (Bar) 10.3 10.4
Liquid-gas ratio (L/h) 3.5/500 3.5/500
Average removal rate (%) 93.4 94.1
Time (h) 53.38 21.38
Regeneration energy
(GJ/tCO2)
2.728 2.711
Outlet gas CO2 concentration and
removal rate 13
Effect of pressure on the
CO2 removal rate
Compared with amine solution, the regeneration energy of CO2 from IL-amine
blending was about 17.4% lower at the same CO2 removal rate and the same
parameters of the absorption tower.
IL-amine blending for CO2 capture
/℃
Effect of temperature on
the CO2 removal rate
Effect of liquid-gas ratio on
the CO2 removal rate
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CO2 separation from landfill gas
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CO2 removal from landfill gas with IL blending
10m3 / h of gas flow
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CO2 removal from landfill gas with IL blending
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Solvent 90% NHD
10% Ionic liquid
Pressure ~ 7 Bar
Gas flow ~1000 L/h
(CO2~33%, CH4~40%)
Fluid flow 420 L/h
Component of the absorbent and the operating parameters
The adding of IL slightly decreased
the CO2 solubility but increased the
selectivity of CO2 / CH4.
CO2 removal from landfill gas with IL blending
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CO2 separation from melamine
industry tail gas
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CO2 / NH3 separation with water
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CO2 / NH3 separation with ILs
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Types ILs Initial pH* pKa
Conventional IL [Bmim][NTf2] 7.13 -
Protic IL [Bim][NTf2] 5.14 6.79
Brønsted acidic IL [HOOC(CH2)3mim][NTf2] 3.52 4.61
Designing of the ILs
Structures of (a) [Bmim][NTf2], (b) [Bim][NTf2] and (c)
[HOOC(CH2)3mim][NTf2]
* pH and pKa of ILs were measured in water and DMSO solution
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Vapor-liquid equilibrium measurement apparatus: a, NH3; b1, b3-5, ball valve; b2, regulating valve; c1, c2,
pressure sensor; d, gas reservoir; e, absorption vessel; f, magnetic stirrer; g, vacuum pump; h, water bath
( )
( )( )
RT a Tp
V b V b V b
Measuring apparatus and EOS
Equation of state:
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Protic IL for NH3 separation
Solubility of NH3 in ILs at 313K
2.69 mol NH3/ mol IL
1.54 mol NH3/ mol IL
0.28 mol NH3/ mol IL
NH3 solubility in protic IL was about 1.7 times than carboxyl-functionalized
IL and 10 times than conventional IL. 24
In-situ FTIR
NMR
Quantum
chemistry
calculation
Schematic for the possible mechanism
of absorption of NH3 by [Bim][NTf2]
Green Chem. 2017, 19, 937-945
Possible absorption mechanism
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NH3 tail gas treatment apparatus
Apparatus for 800M Nm3/a gas treatment 26
Acknowledgements
These studies were financially supported by the National
Natural Science Fund for Distinguished Young Scholars
(21425625) and the CLIMIT program and the Research
Council of Norway (215732).
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