Pilot plant studies of new solvents for post combustion CO capture · 2011-07-08 · Laboratory of...

Laboratory of EngineeringThermodynamicsProf. Dr.-Ing. H. Hasse

International Conference on Energy Process Engineering, 20.-22. June 2011, Frankfurt

Pilot plant studies of new solvents for postcombustion CO2 capturecombustion CO2 capture

Inga Tönnies Hari Prasad Mangalapally Hans HasseInga Tönnies, Hari Prasad Mangalapally, Hans Hasse

Laboratory of Engineering Thermodynamics (LTD)University of Kaiserslautern


COt t dChallenges:

Absorption-desorption process

CO2treated gas

washing sections• Dimensions• Energy demand

condensate

kdesorber

absorberprewasher

make-up

flue gas

lean solventrich solvent Reactive solvents:

2

Reactive solvents:Reference: 0,3 g/g MEA in H2O

20.06.2011 Inga Tönnies


Requirements:

New solvents tested at UNIKL within CESARRequirements: • high cyclic capacity• fast kinetics• environmentally acceptable stable non toxic non corrosive

Solvent Composition

• environmentally acceptable, stable, non-toxic, non-corrosive

p

MEA 0,30 g/g monoethanolamine (MEA)

CESAR 1

CESAR 3

0,29 g/g aminomethylpropanol (AMP)0,18 g/g piperazine (PIP)

0 32 g/g ethylendiamine (EDA)CESAR 3

CESAR 5

0,32 g/g ethylendiamine (EDA)

0,27 g/g aminomethylpropanol (AMP)0 19 g/g ethylendiamine (EDA)


0,19 g/g ethylendiamine (EDA)


ar

600MEA

Gas solubilites

ure

/ mba

400

500CESAR 1CESAR 3 CESAR 5

al p

ress

u

300

CO

2 pa

rti

100

200 Cyclic capacity

C

CO –loading / mol CO /kg solvent0 1 2 3 4 5 6

0

Cyclic capacity:CESAR 1 > CESAR 3 , CESAR 5 > MEAOptimum solvent flow:

CO2–loading / mol CO2/kg solvent

Optimum solvent flow:CESAR 1 < CESAR 3 , CESAR 5 < MEA

20.06.2011 Inga Tönnies 4


M ti ti

Laboratory pilot plant testing

Motivation• Cheaper than large pilots• Solvent comparisonp

• energy• L/G optimum• operabilityoperability

• Validation of process models

Limitations• Limited height• No long term testing• Heat losses



Pilot plant @ TU Kaiserslautern

Flue gas source Natural gas burner / CO2 recycle

Flue gas flow 50 - 120 kg/hSolvent flow 50 350 kg/hSolvent flow 50 - 350 kg/hCO2 concentration 3.8 – 14.8 Vol% (dry)Packing type Sulzer BX (500 m2/m3)g yp ( )Packing height / Ø Absorber: 4.25 m / 0.125 m

Desorber: 2.55 m / 0.125 mWashing section: 0.4 m / 0.125 m

Analytics Online gas analytics (CO2, O2)Liquid analytics (amine, CO2, H2O)q y ( , 2, 2 )Flows, temperatures, pressures, levels



Component mass balanceMass balance CO2

Measurement quality

12

14CESAR 5MEAkg

/h

Component mass balance(CESAR 5)

e/ %

Mass balance CO2

12

8

10

12 MEA

alyt

ics

/

sba

lanc

e

+5 % 6

8

10

12O2

N2

H2O

4

6

8

liqui

d an

a

n in

mas

s

-5 %

0

2

4

0

2

4

CO

2-flo

w l

Dev

iatio

n-6

-4

-2

0 2 4 6 8 10 12 140

CO2-flow gas analytics / kg/h

C

Experiment no.

D 0 1 2 3 4 5 6 7 8 9 10 11 12

High quality of experimental data



Varied parameter Const parameters Result

Parameter studiesVaried parameter Const. parameters Result

Solvent flow Gas flow (80 kg/h, F = 1.7 Pa0.5) Removal rate (90%) Energy optimum

Gas flow L/GRemoval rate (90%) Kinetic limitation?

/t C

O2

6,0

6,5

4,0

4,1

/t C

O2

ergy

/ GJ/

4,5

5,0

5,5

3,8

3,9

ergy

/ GJ/

Spe

c. e

ne

80 120 160 200 240 280 3203,5

4,0

4,5

0 8 1 0 1 2 1 4 1 6 1 83,6

3,7S

pec.

ene

8

F-Factor / Pa0.5

80 120 160 200 240 280 320

Solvent flow / kg/h

0,8 1,0 1,2 1,4 1,6 1,8



Solvent flow variation7,0

J/t C

O2

6,0

6,5MEACESAR 1CESAR 3 CESAR 5

ergy

/ GJ

• Removal 90%• pCO2 = 100 mbar5,0

5,5CESAR 5

pec.

ene • G = 80 kg/h

4,0

4,5

Sp

50 100 150 200 250 3003,0

3,5

Solvent flow / kg/h

CESAR 1: Reduction in energy by 20% compared to MEA, reduction in

50 100 150 200 250 300

9

CESAR 1: Reduction in energy by 20% compared to MEA, reduction in optimum solvent flow by 50%



Gas flow variation at constant L/G

4 6

4,4

4,6MEACESAR 1CESAR 3J/

t CO

2

4,0

4,2CESAR 5

ergy

/ GJ

• Removal 90%• pCO2 = 100 mbar

3,8

,

pec.

ene

p 2• L/G = 2.5 (optimum MEA)

0 8 1 0 1 2 1 4 1 6 1 83,4

3,6Sp

0,8 1,0 1,2 1,4 1,6 1,8F-Factor / Pa0,5

CESAR 3 and CESAR 5 show strongest kinetic limitations

10

CESAR 3 and CESAR 5 show strongest kinetic limitations



Comparison with results from Esbjerg• Esbjerg plant: Absorber with 17 m of Mellapak 2.X (205 m2/m3), j g p p ( ),

diameter 1,1 m, Scale factor app. 100• Direct comparison difficult: different CO2 partial pressure, amine

concentration desorber pressure plant specific differences

Solvent Energy / GJ / t CO2 Improvement over MEA / %UNIKL E bj UNIKL E bj

concentration, desorber pressure, plant specific differences

UNIKL Esbjerg UNIKL EsbjergMEA 4.1 3.6 (3.6)* - -CESAR 1 3 2 3 1 (2 9)* ~20 % ~15 % (20%)*CESAR 1 3.2 3.1 (2.9) 20 % 15 % (20%)

CESAR 3 3.8 3.5 (3.4)* ~7 % ~3 % (5%)*

CESAR 5 3.7 Not tested ~8 % Not tested

Solvents that showed improvement in our pilot plant show a similar

* with intercooling

11

p p pimprovement at Esbjerg



COCO2

• Only gas solubility at 40°C and 120°C, heat

Screening method for new solvents

Desorber energy balance:

capacity and enthalpy of absorption as input

m h≈ ⋅∆&2CO abs

t i

Q&Reboiler1. Desorption of CO2

m h

m c T

+ ⋅∆

+ ⋅ ⋅∆

&

&

2

stripv, H O

solvent HXp solvent

2. Stripping steam

3. Heating of solvent

m c T+ ⋅ ⋅∆&2

p, solvent

strip refluxp, H O

g

4. Heating of reflux

• Estimation of stripping steam from equilibrium stage method



Results of screening method for new solvents5,5

MEA

J/t C

O2

4 5

5,0

MEACESAR 1CESAR 3CESAR 5

ergy

/ GJ

4,0

4,5• Removal 90%• pCO2 = 110 mbar

pec.

ene

3,0

3,5

Sp

0 1 2 3 4 5 62,5

3,0

L/G / kg/kgOrder correctly represented: CESAR 1< CESAR 3 CESAR 5 < MEA

13

CESAR 1< CESAR 3, CESAR 5 < MEAEnergy underestimated since e.g. kinetic effects not considered



Summary• Three solvents from EU project CESAR tested in our pilot plantThree solvents from EU project CESAR tested in our pilot plant

• CESAR 1 offers energy reduction by 20 % over MEA

• High quality experimental dataHigh quality experimental data

• Energy savings confirmed in Esbjerg pilot plant

• Screening method able to identify promising solvents based on gasScreening method able to identify promising solvents based on gas solubility at 40°C and 120°C

AcknowledgementEU C i i f fi i l t ithi th CESAR j tEU Commission for financial support within the CESAR project



Th kTh k ff tt titt ti !!Thank Thank youyou forfor youryour attentionattention!!

1520.06.2011 Inga Tönnies 15

Pilot plant studies of new solvents for post combustion CO capture · 2011-07-08 · Laboratory of...

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