Abdurahim Abdulkadir, Mohammad Abu Zahra pdfs/5b_3_Abd… · Abdurahim Abdulkadir, Mohammad Abu Zahra . 2. nd. PCCC, 17-20 Sep, 2013 Bergen, Norway . 2 . Research university Graduate

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Measurements of Reaction Enthalpies for Aqueous amine solutions for post combustion carbon capture applications

Abdurahim Abdulkadir, Mohammad Abu Zahra

2nd PCCC, 17-20 Sep, 2013 Bergen, Norway

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Research university Graduate level (MSc & PhD) only Focused on sustainable technology and clean energy In collaboration with Massachusetts Institute of Technology (MIT)

MASDAR INSTITUTE A RESEARCH DRIVEN UNIVERSITY

Masdar Institute – 100% solar powered campus

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SEPARATION TECHNOLOGY LABORATORY (STL)

The Research Focus is the CO2 Post-Combustion Capture

http://www.masdar.ae/en/home/index.aspx

4 Wednesday, September 25, 2013

PRESENTATION OUTLINE

Introduction Materials Experimental Method Results Conclusions

Future Work

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The OVERALL SCOPE OF THE PROJECT

• Project Title : DEVELOPMENT OF NEW SORBENT SYSTEMS FOR CO2 POST-COMBUSTION CAPTURE

• Phase I: Process Simulation and Solvent Screening for Alkanolamine blends

• Phase II: Thermodynamic measurement and modeling of heat of absorption and specific heat of the most promising stand-alone and blends of amine from phase I

• Phase III : Reaction Kinetics measurements of the most promising stand-alone and blends of amine from phase I


ABSORPTION CAPACITY SET-UP

EQUILIBRIUM EQUIPMENT SET-UP

Phase I of the Project

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Wednesday, September 25, 2013

Solvent Screening set-up

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RESULTS FROM PHASE I


Ref: Adewale Adeosun

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INTRODUCTION


o Post-combustion capture (PCC) with amine scrubbing is seen as a useful route to reducing carbon emissions

o PCC is energy intensive – solvent regeneration accounts for the vast majority of costs associated with CCS, thus there is great interest in solvent design and solvent blends

o Sophisticated thermodynamic treatment required – cubic EoS not applicable, quuasichemical-based theories not ideal

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INTRODUCTION


Heat of absorption is the Combination of heat of dissolution and heat of reaction between CO2 and amine

Heat of absorption = - Heat of Regeneration • High Heat of Absorption – favors to increase the kinetics of the reaction and reduces the absorption height

• Low Heat of Absorption – favors to decrease the regeneration cost by reducing the steam supply

The best solvent is the one with High absorption heat Easily can be regenerated

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Heat of absorption from Model and Experiment

• Heat of absorption from Model is obtained from Vapor-Liquid Equilibrium (VLE) using Gibbs Helmholtz thermodynamic relation which is (at particular loading)

Differential in loading but integral in temperature

• Heat of absorption from Calorimeter is combination of heat of dissolution and heat of reaction of CO2 and amine from zero loading to the final loading (at particular temperature or isothermal)

Integral in loading but differential in temperature

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Calorimetric measurement • Direct calorimetric measurements provide accurate values of the enthalpy of

absorption, reflecting both the heat effects due to physical dissolution of the gas in the solvent and the chemical reaction between CO2 and amine

• The enthalpy of CO2 absorption is directly related to the reaction kinetics of the solvent in the absorber and the energy requirement for the solvent regeneration, and it is desirable that the value be known as accurately as possible to avoid Uneconomic over design for absorber and stripper.


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MATERIALS Monoethanolamine OR MEA

Viscous colourless liquid

Boiling point = 1700C Vapor Pressure = 30 Pa at 200C pH = 12.1 (25% solution)

Solubility = Miscible in water Diethanolamine OR DEA

Viscous colourless liquid Boiling point = 2170C Vapor Pressure = <1 Pa (at 20 0C) pH = 11.5 at 105 g/l at 250C Water Solubility = 105 g/l at 200C


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MATERIALS Piperazine or PZ (poly secondary cyclic amine)

White Crystalline Solid

Boiling point = 145 0C Vapor Pressure = 21 Pa at 200C pH = 10.8-11.8 at 100 g/l

Completely soluble in water

3-Piperidinemethanol OR 3-PM

(Secondary cyclic alkanolamine)

White Crystalline Solid Boiling point = 106 0C at 47 Pa Vapor Pressure = 306.6 Pa (at 25 0C) Completely soluble in water


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Tertiary/sterically amines: N-Methyldiethanolamine OR MDEA

Viscous colourless liquid

Boiling point = 1700C Vapor Pressure = 1 Pa at 200C pH = 11.5 at 100 g/l at 200C

Completely soluble in water

2-Amino-2-methyl-1-proanol OR AMP

Viscous colourless liquid Boiling point = 165 0C Vapor Pressure = <10 Pa at 25 0C pH = 11-12 at 8.9 g/l at 250C water Solubility = 8.9 g/l at 200C


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EXPERMENTAL METHOD

Micro-reaction calorimeter THT

Bench-scale 85% phosphoric acid titration set-up

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Thermo gravimetric differential scanning calorimeter (TGA-DSC)


CSIRO Energy Center


Micro-Reaction Calorimeter Experimental Set-up


Micro-Reaction Calorimeter Experimental Set-up

N2 CO2

Dessiccant column

Gas in

T1 V1

V3

MFC

By-pass

Gas out

T2 V2

Calorimeter

Analysiscell

Referencecell

Shunt

Cap


Micro-Reaction Analysis

Heat of Absorption for 3/3 M MEA/3PM


Micro-Reaction Analysis

Specific Heat of 30 wt % MEA



Electrical signal over time in the measurement of cp in a 40wt% DEA solution from 25 – 135oC.

-80

-60

-40

-20

0

20

40

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

electr

ical si

gnal

(uV)

time (seconds)

-80

-60

-40

-20

0

20

40

5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 7000

electr

ical si

gnal

(uV)

time (seconds)

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The specific heat capacity of the sample, cp in J/g.K is given by:

)AA.(m

)AA.(m)T(cp)(

boltanocsample

blanksampleoct

oct −−

=−−

Tcp

• T is the average temperature of the ramp (i.e. ramp from 20 – 30oC is reported at 25.0oC),

• Asample, and Ablank and Aoctanol are the trapezoidal numerical integration of the ZDSC electrical singal (in µV.s) of the sample, blank, and standard (1-octanol), respectively over the time of the temperature increment.

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Specific Heat of Stand-alone Amines in the range of 30-80 0C

RESULTS


30 40 50 60 70 803.5

3.6

3.7

3.8

3.9

4

4.1

4.2

4.3

Temprature (0C)

CP (J

/0C*

g)

20wt%PZ10wt%AMP3M-3PM2M-3PM

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Specific Heat of Blends of Amines in the range of 30-80 0C

RESULTS


30 40 50 60 70 803.5

3.6

3.7

3.8

3.9

4

4.1

4.2

4.3

Temprature (0C)

CP (J

/0C*

g)

10/20wt%-AMP/PZ10/20wt%-MDEA/PZ3/3M-MEA/3PM3/2M-MEA/3PM2/3M-MEA/3PM

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Thermo gravimetric differential scanning calorimetry (TGA-DSC)

RESULTS

Specific Heat Capacities

Work in progress for

Amine Blends


RESULTS

Aqueous solutions of MEA,DEA,MDEA , PZ and blends@ 400C

AMINES CONCENTRATION HEAT OFABSORPTION ( kJ/mol CO2 )

LOADING CAPACITY (mol CO2/mol Amine)

MEA 30wt% 87.8 0.51

MDEA 10wt% 56.76 0.63

AMP 10wt% 70.25 0.72

PZ 20wt% 115.15 0.62

AMP/PZ 10/20wt% 93.4 0.82

MDEA/PZ 10/20wt% 79.75 0.78

Work in progress for

60-120 0C


CONCLUSIONS • A micro reaction calorimeter was used to measure the enthalpies of absorption and heat

capacity of different aqueous solutions of MEA,DEA,MDEA,AMP and PZ with their blends

• The significant difference in enthalpies is mostly due to the endothermic bicarbonate formation reaction in the case of tertiary amine, which reduce the magnitude of the enthalpy while high enthalpy of absorption is measured for primary amine due to the exothermic carbamate formation

• High Heat of absorption of piperazine reduced by blending it with tertiary amine and

sterically hindered amines .

• Loading capacity of Piperazine with sterically hindered amine is higher than loading

capacity of Piperazine with tertiary amine.

• MDEA/PZ blend is having low heat of absorption and high CO2 loading capacity.

• The measured data can be used for modeling CO2 absorption/desorption system when the

above aqueous solutions are used


FUTURE WORK

• Thermodynamic Modeling of the heat of absorption for MEA,DEA,MDEA,3-PM,AMP and their blends using activity model, the Specific Ion Interaction Theory (SIT) proposed by Dr. Graeme Puxty from CSIRO

• Measurement of heat of absorption for different aqueous amine solutions at different temperature ranges and CO2 loading

• Measurement of Specific heat and heat of absorption of other aqueous amine solutions with their blends

• Phase II , Kinetics of amine blends and also advanced amine solvent screenging

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Thank You For Your Attention

Documents

Abdurahim Abdulkadir, Mohammad Abu Zahra pdfs/5b_3_Abd… · Abdurahim Abdulkadir, Mohammad Abu Zahra . 2. nd. PCCC, 17-20 Sep, 2013 Bergen, Norway . 2 . Research university Graduate