Pilot Tests and Rate-Based Modelling of CO Capture in

José-Francisco Pérez-Calvo, Daniel Sutter, Matteo Gazzani, Marco Mazzotti Institute of Process Engineering, ETH Zurich

Distillation & Absorption 2018, September 16-19, 2018 Florence, Italy

Pilot Tests and Rate-Based Modelling of CO2 Capture in Cement Plants Using an Aqueous Ammonia Solution

| | Institute of Process Engineering 19-Sep-18 José-Francisco Pérez-Calvo, [email protected] 2

Talk outline

Introduction

Scope of the study

Pilot plant tests of the CO2 absorber

Rate-based model development

Rate-based model assessment using pilot plant test results

Conclusions

Pilot tests Introduction Scope Rate-based model Model assessment Conclusions

| | Institute of Process Engineering

Global cumulative CO2 emissions reductions 2020-2050

19-Sep-18 José-Francisco Pérez-Calvo, [email protected] 3

CO2 emissions from cement


2.2 Gt CO2 <> 7% global CO2 emissions

Source: International Energy Agency and Cement Sustainability Initiative (2018) Technology Roadmap – Low-Carbon Transition in the Cement Industry.

Fuel

Calcination

Electricity

CO2 emissions intrinsic to the

cement manufacturing process

Higher CO2 concentration in the

flue gas with respect to only

combustion


The Chilled Ammonia Process


Similar process

complexity

Stable in the presence of

impurities

Global availability

Low environmental

footprint and cost

Competitive thermal

energy for regeneration


The CO2-NH3-H2O system

Vapor

Liquid

Solid

H2O ↔ OH- + H+ NH3 + H+ ↔ NH4

+

HCO3- ↔ CO3

2- + H+ CO2 + OH- ↔ HCO3

-

CO2 + 2NH3 ↔ NH2COO- + NH4+

CO2 H2O NH3

CO2 H2O NH3

(NH4)HCO3 (NH4)2CO3·2NH4HCO3

(NH4)2CO3·H2O NH2COONH4 Ice

[1] Darde et al. Ind Eng Chem Res 49 (2010) 12663-74 [2] Jänecke Z Elektrochem 35 (1929) 9:716-28

SRK for gas fugacities

Extended UNIQUAC (Thomsen-Darde[1])

Solubility data for solids fitted on Jänecke[2]

Pure solids, activity = 1

VLE

SLE

Thomsen model to predict the system thermodynamics



Phase diagram: CO2-NH3-H2O system

Pure solids

BC: ammonium bicarbonate

(NH4)HCO3

SC: ammonium sesqui-carbonate

(NH4)2CO3·2NH4HCO3

CB: ammonium carbonate

(NH4)2CO3·H2O

CM: ammonium carbamate

NH2COONH4

Light blue area:

Two-phase region where the solid

exists in its mother liquor

Red area:

The algorithm does not converge

10°C

1 bar

S: Solid

L: Liquid

V: Vapor



Phase diagram: CO2-NH3-H2O system

[1] Jänecke Z Elektrochem 35 (1929) 9:716-728 [2] Sutter et al. Chem Eng Sci 133 (2015) 170-180

[1]

[2]



From power plants to cement plants

NG power plants

~ 4 %vol. CO2

Coal-fired power plants

~ 14 %vol. CO2

Change of operating

conditions in the

CO2 absorber Cement plants

15 – 35%vol. CO2

Pilot plant CO2 absorption tests

1

Validation of rate-based models from literature

2

Development of new rate-based model

3

Assessment of new rate-based model performance

4

Research question:

Are the available rate-based models

valid or do they require adaptations?



Test matrix definition

[1] Yu et al. Chem Eng Res Des 89 (2011) 1204-1215


CO2 content in

flue gas (%vol)

CSIRO[1]

This work

8.5 – 12

Up to 35

Packing type

Random 25 mm Pall ring

Structured Flexipac M 350X

Liquid properties


Test matrix definition: Preliminary process optimization

Cement Plant

Power Plant

22%

18%

14% vol. CO2


Pérez-Calvo et al. Energy Procedia 114 (2017) 6197-6205


Test matrix definition: Preliminary process optimization


[1] Yu et al. Chem Eng Res Des 89 (2011) 1204-1215

CO2 content in

flue gas (%vol)

CSIRO[1]

This work

8.5 – 12

Up to 35

Packing type

Random 25 mm Pall ring

Structured Flexipac M 350X

CSIRO pilot

tests[1]

Pilot tests – This work

Liquid properties


Test rig


Controlled and

measured variables

Flowrate Temperature Pressure CO2 concentration NH3 concentration

CO2-lean solution Controlled and

measured variables

Flowrate Temperature CO2 concentration NH3 concentration

Measured variables

Flowrate Temperature Pressure CO2 concentration NH3 concentration

Measured variables

Flowrate Temperature CO2 concentration NH3 concentration


Pilot test results

Raw data Steady-state

detection

𝑄Lin

,L/h

𝑄

Gou

t,A

m3

/h

𝑇,°

C

𝑃 Go

ut,k

Pa

𝑦,v

ol%

𝐶

CO

2,m

ol/

L

𝐶N

H3

,mo

l/L

𝑡, min

𝑇Lout

𝑇Gout

𝑇Lin

𝑦CO2

in

𝑦CO2

out

𝑦NH3

out

𝑀CO2

out

𝑀CO2

in

𝑀NH3

out

𝑀NH3

in

SS detected

No SS


Data Reconciliation

and

Gross Error Detection 𝒖, 𝝈 𝒖, 𝝈

82 experimental points


Rate-based model


𝑁CO2= 𝐴eff𝐾G,CO2

(𝑝CO2,G − 𝑝CO2,L∗ )

Experimental value or

computed by the model

E = 𝑓(L-phase reactions)

𝐴eff = 𝑓hydrodynamics

transport properties

Rochelle model[1] to compute the effective G-L interfacial area

(𝑝CO2,G − 𝑝CO2 ,L∗ ) = 𝑓 thermodynamics

Thomsen thermodynamic model to compute the driving force

1

𝐾G,CO2

=𝑅𝑇

𝑘𝑔,CO2

+𝐻CO2

E𝑘𝑙,CO20

𝑘𝑔,CO2

𝑘𝑙,CO2

0 = 𝑓hydrodynamics

transport properties

Rochelle model[1] to compute the G-film and L-film mass-transfer coefficients

𝐻CO2= 𝑓 thermodynamics

Partition coefficient computed by Thomsen model

[1] Wang et al. Ind Eng Chem Res 55 (2016) 5357-5384

Range of structured packings

X, Y, Z, 150-350

Aqueous solutions for CO2

capture

Predicts SLE in addition to VLE


L-phase reaction kinetics – Validation of literature models

Pilot tests Introduction Scope Rate-based model Sensitivity analysis Conclusions

CO2 + 2NH3

𝑘cm NH2COO− + NH4

+

CO2 + OH−𝑘bc

HCO3−

Single irreversible reaction[1,2] E = 𝑓 Ha [3,4]

[1] Jilvero et al. Ind Eng Chem Res. 53 (2014) 6750-6758 [2] Ahn et al. Int J Greenh Gas Control. 5 (2011) 1606-1613 [3] van Swaaij and Versteeg. Chem Eng Sci. 47 (1992) 3181-9195

[4] Levenspiel (3rd ed.) (1999) Chemical Reaction Engineering. New York: John Wiley & Sons [5] Pinsent et al. Trans Faraday Soc. 52 (1956) 1594-1598 [6] Puxty et al. Chem Eng Sci. 65 (2009) 915-922

𝑇(°C)

𝑘a

pp

(s−

1)

5%wt NH3

+ 95%wt H2O

x 104

Puxty model[6]

Pinsent model[5]

CO2 + NH3 → NH2COO− + H+

NH3 + H+ → NH4+

𝑟cm = 𝑘app𝐶CO2

𝑟cm = 𝑘cm𝐶NH3𝐶CO2

Simple

mechanism

Ha =

𝑘cm𝐶NH3𝐷CO2,L

𝑘𝑙,CO2

0

Pinsent model

Puxty model

𝑁CO2 exp, kg/h

𝑁C

O2

mo

de

l,kg/

h


L-phase reaction kinetics – Parameter estimation

Pilot tests Introduction Scope Rate-based model Sensitivity analysis Conclusions

CO2 + 2NH3

𝑘cm NH2COO− + NH4

+

CO2 + OH−𝑘bc

HCO3−

Single irreversible reaction[1,2] E = 𝑓 Ha [3,4]

CO2 + 2NH3 → NH2COO− + NH4+

Termolecular

mechanism

Ha =

𝑘cm𝐶NH3

𝑛 𝐷CO2,L

𝑘𝑙,CO2

0

CO2 + NH3 + H2O → NH2COO− + H3O+

CO2 + NH3 ↔ NH3+COO−

Zwitterion

mechanism NH3+COO− + NH3 → NH2COO− + NH4

+

𝑟cm = 𝑘cm𝐶NH3

𝑛 𝐶CO2

Empirical expression

1 ≤ 𝑛 ≤ 2

𝑘cm = 𝑘0cm,Trefexp −

𝐸a,cm

𝑅

1

𝑇−

1

𝑇ref

𝑘cm(𝑇 = 𝑇ref = 298 K) 𝐸a,cm 𝑛

m3

kmol s

kJ

kmol

−

This work 167 27,800 1.3

Pinsent 431 48,500 1

𝑁C

O2

mo

de

l,kg/

h

This work

Pinsent model

𝑁CO2 exp, kg/h

NH3+COO− + H2O → NH2COO− + H3O+


Rate-based model performance assessment (1)


𝑙CO2, molCO2

/molNH3

𝑁C

O2,k

g/h

𝐶NH3= 5.5 − 5.8 m

𝑇L = 16 − 20°C 𝐿

𝐺= 8.5 − 8.8 kg/kg

𝑣𝑠,G = 0.9 − 1.0 m/s

𝒑𝐂𝐎𝟐,𝐆 = 𝟔 − 𝟕 𝐤𝐏𝐚

𝒑𝐂𝐎𝟐,𝐆 = 𝟏𝟐 − 𝟏𝟑 𝐤𝐏𝐚

𝒑𝐂𝐎𝟐,𝐆 = 𝟏𝟔 − 𝟏𝟖 𝐤𝐏𝐚

𝐶NH3= 5.8 − 6.1 m

𝑇L = 20 − 23°C 𝐿

𝐺= 10.7 − 11.5 kg/kg

𝑣𝑠,G = 0.7 m/s

𝑁C

O2,k

g/h

𝑙CO2

, molCO2/molNH3

𝒑𝐂𝐎𝟐,𝐆 = 𝟏𝟕 − 𝟏𝟗 𝐤𝐏𝐚

𝒑𝐂𝐎𝟐,𝐆 = 𝟑𝟎 − 𝟑𝟏 𝐤𝐏𝐚

Set A – low CO2 loading Set B – high CO2 loading


Rate-based model performance assessment (2) 𝑁

CO

2,k

g/h

𝑁C

O2,k

g/h

𝑇L, °C 𝑇L, °C

𝑝CO2 ,G = 18 − 19 kPa

𝑙𝐶𝑂2= 0.47 − 0.54 molCO2

/molNH3

𝐿

𝐺= 7.6 − 8.8 kg/kg

𝑣𝑠,G = 0.9 − 1.1 m/s

𝑪𝐍𝐇𝟑= 𝟏𝟎 𝐦

𝑪𝐍𝐇𝟑= 𝟔 𝐦

𝑪𝐍𝐇𝟑= 𝟒 𝐦

𝑪𝐍𝐇𝟑= 𝟒 𝐦

𝑪𝐍𝐇𝟑= 𝟔 𝐦

𝑪𝐍𝐇𝟑= 𝟏𝟎 𝐦

𝑝CO2 ,G = 17 − 19 kPa

𝑙𝐶𝑂2= 0.52 − 0.54 molCO2

/molNH3

𝐿

𝐺= 10.7 − 11.4 kg/kg

𝑣𝑠,G = 0.7 m/s

Set C – low CO2 loading Set D – high CO2 loading



Conclusions

The Chilled Ammonia Process is a very promising technology for CO2 capture from cement plants

It has been confirmed experimentally that the higher CO2 concentration in the flue gas enhances the absorption of CO2

CO2 capture efficiencies as high as 60% have been obtained in only 3 m high packing

The results of the CO2 absorption pilot plant tests have shown that the rate-based models available in the literature are outside their range of validity when used at the conditions of the CAP applied to cement plants

Therefore, a new rate-based model has been developed, that:

Is able to reproduce the trends of the CO2 absorption rate obtained experimentally

Can be used with engineering purposes for the simulation and optimization of the CAP applied to cement plants for CO2 capture



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

José-Francisco Pérez-Calvo, Daniel Sutter, Matteo Gazzani, Marco Mazzotti Institute of Process Engineering, ETH Zurich

Distillation & Absorption 2018, September 16-19, 2018 Florence, Italy

Pilot Tests and Rate-Based Modelling of CO2 Capture in Cement Plants Using an Aqueous Ammonia Solution

Documents

Pilot Tests and Rate-Based Modelling of CO Capture in