3rd Post Combustion Capture Conference(PCCC3)

Regeneration performance  of aqueous CO2‐DEEA in a Packed Column

ith DX R d P kiwith DX Random PackingPCCC3 Regina Canada Sept 9 2015PCCC3, Regina, Canada, Sept. 9, 2015

Hongxia Gao, Bin Xu, Zhiwu(Henry) Liang,g , , ( y) g,

Raphael Idem, Paitoon Tontiwachwuthikul

Joint International Center for CO2 Capture and Storage (iCCS) 

D t f Ch i l E i i H U i it PR ChiDept. of Chemical Engineering, Hunan University, PR China

Outline

BackgroundBackground

About iCCS Hunan University in Chinay

Amine‐based  CO2 capture

Experimental section

Results and discussion

Summary

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Where is Hunan University in China?

Beijing, Chinaj g,

Hunan University, Changsha

Hong Kong

3

ZhangjiajieMawangtui, 2000 years ago

HUNANMawangtui, 2000 years ago

Hometown of Mao ZD

4

Current Member : 37 5 Professors 2 Engineers 2 Post doctors 2 Post-doctors 28 Graduates

Working for: Solvent Development Kinetics & Mass Transfer P D l Process Development Pilot Test CO Utilization

5

CO2 Utilization

1.Background: Amine‐based  CO2 capture

?？High Energy Consumption

Simulation

Contactor

NH2 CH2 CH2 OH

CH2 CH2 OHNH

OHCH3

OOS

6

Traditional absorption‐stripping process CH2 CH2 OHOO

Solvent

1.Background: Amine‐based  CO2 capture

Absorption capacityAbsorption capacity——Kim, 2009; Xu et al., 2014Kim, 2009; Xu et al., 2014OH , ; ,, ; ,

Absorption heatAbsorption heat——Kim, 2009; Xu, et al., 2014Kim, 2009; Xu, et al., 2014

N

Absorption rateAbsorption rate——Vaidya, et al., 2014Vaidya, et al., 2014

D d iD d i

N,N-Diethylethanolamine

Degradation rateDegradation rate——Gao, et al., 2015Gao, et al., 2015

(DEEA)(DEEA)

Regeneration EnergyRegeneration Energy  

Overall objective:Overall objective: Comprehensively investigate the regeneration Comprehensively investigate the regeneration 

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performance of DEEAperformance of DEEA

2.Experimental section

Stripper: glass, vacuum interlayer 

(Φ28mm H=0 5m)(Φ28mm, H=0.5m)

Packing:Φ3×3mm, 316L DX

R b il Reboiler: 

a triple‐layer glass kettle

Operating Conditions

CDEEA = 1.7‐3.8 mol/LCDEEA  1.7 3.8 mol/L

TFeed = 70‐85oC  

α =0 085 0 318 mol/mol αlean =0.085‐0.318 mol/mol

αrich =0.7‐0.8 mol/mol

L 40 80 l/ i

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Schematic diagram of desorption process. L = 40‐80ml/min

Calculation of Reboiler heat dutyCalculation of Reboiler heat duty

)( iPb ttCmH )( ,,, ooutoinoPoreb ttCmH

)(min COleanricheACO Mnm vapsenabsrebQQQQ

22)(min COleanricheACO

)/1()(ln 2

, 2 TdPd

RHQ COCOabsabs rebHQ )/1( Td

2( ) /sen solvent P reboil input COQ VC T T m Where

2COreb m

Q

2Where

Mo—mass flow rate (kg/h)

C heat capacity (MJ/kg ◦C)senabsrebvap QQQQ

Cp,o—heat capacity (MJ/kg∙◦C)

tin,o and tout,o —inlet, outlet temperature (◦C) of 

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the heating oil

3.Results and discussion

Experimental Validation using 5 mol/L aqueous MEA solution

Lean CO2 loading,  Qreb, GJ/t CO2

mol/mol Literature 1,2 This study

0.20‐0.24 5.0‐10.0 5.027 (0.24)( )

0.24‐0.29 4.0‐4.9 4.766 (0.27)

0.29‐0.35 3.0‐3.9 3.675 (0.30)

[1]Sakwattanapong, et al., 2005. Industrial & Engineering Chemistry Research 44, 4465-4473.

[2] Idem, et al., 2006. Industrial & Engineering Chemistry Research 45, 2414-2420.

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3.Results and discussion

Effects of Lean CO2 loading on Qreb(C= 3 mol/L, α rich= 0.7mol /mol, Tfeed= 75◦C). 

Mass balance errorMass balance error

Qreb decreased as Lean/Rich loading increased

Lean CO2 loading    , H2O partial pressure   ;  thus, Qreb

3.Results and discussion

Effects of DEEA concentration on Qreb(α lean= 0.27 mol /mol, α rich= 0.70 mol /mol, Tfeed= 75◦C).

Qreb decreased as DEEA concentration increased

increased partial CO2 pressure leading to a decreasing partial pressure of 

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p 2 p g g p pwater vapor

3.Results and discussion

1. Keep △α×L and C constant

△α L

Fi d t f t i d CO

△α      L 

Fixed amount of stripped CO2

(L×C×△α) 2. Keep L×C and △α constant(L×C×△α)

Total absorption  capacityC     L

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3.Results and discussionSynergistic effect of cyclic CO2 capacity and solution flow rate on Qreb

(C= 3 mol/L, αrich= 0.70 mol /mol, Tfeed= 75◦C).

Qreb first decreased and then increased as cyclic CO2 capacity increased

Because:   (1) High H2O partial pressure

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g 2 p p

(2) Qreb mainly determined by Qsen

3.Results and discussionSynergistic effect of DEEA concentration and solution flow rate on Qreb

(α lean= 0.27mol /mol, α rich= 0.70 mol /mol, Tfeed= 75◦C).

Qreb decreased as DEEA concentration increased

Increase of CO being absorbed per unit volume of aqueous DEEA solution

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Increase of CO2 being absorbed per unit volume of aqueous DEEA solution with a increase of C

4. Summary

Regeneration performance of CO2 stripping from aqueous DEEA  solution was comprehensively studiedsolution  was comprehensively studied.

Qreb decreased as the DEEA concentration increased. 

The optimal operating points were obtained with the variation of lean CO2 loading. 2 g

Synergistic effects of Δα×L and C×L on Qreb were also investigated.

3M DEEA has a lower reboiler heat duty of 2.03 GJ/ton, which is supposed to be validated using pilot plant in the future. 

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Acknowledgements

• National Natural Science Foundation of China (NSFC Project Nos.21376067, 21476064 & 2150110514)

•Key Project of the National Science & Technology Support Plan (MOSTProject Nos. 2012BAC26B01 & 2014BAC18B04)j )

•Ministry of Education of PR. China ‐Innovation Team (No. IRT1238)

•Shaanxi Yanchang Petroleum (Group) Co., LTD.

•CETRI at the University of Regina

•Hunan University

•China Scholarship Council (CSC)

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•China Scholarship Council (CSC)

Thank youThank you

9/12/2015Faculty of Engineering& Applied Science

School of Chemistry and Chemical

EngineeringCollege of Chemistry and Chemical Engineering

Hunan UniversityJoint International Center for CO2

Capture and Storage (iCCS)