M.S. Thesis Defense Presentation Adviser - Professor Liang-Shih Fan (fan.1@osu.edu)

1. High Pressure Steam Reactivation of Calcium Oxide
(CaO) Sorbents For Carbon Dioxide (CO2) Capture
Using Calcium Looping Process
Masters’ Thesis Defense
By
Amoolya Dattatraya Lalsare
Advisor: Prof. Liang-Shih Fan

2. 2
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
• Introduction
• Experimental Methodology
• Results and Discussions
• Conclusions
• Future Work

3. 3
Energy Outlook and Carbon Emissions in the US
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
 Current CO2 levels in the atmosphere1:405 ppm
 In 2013, CO2 accounted for 82% of greenhouse
gas emissions in the US2
 Electricity production accounts for 37% of all
CO2 emissions and 31% of all greenhouse gas
emissions2
 Coal and natural gas used as fuel for atleast
66% of total electricity generated in the US in
20153.
Figure: United States Electricity Generation by Fuel Type
TrillionKW-hour1. Trends in Atmospheric CO2-NOAA
2. Electricity in the United States - U.S. EIA

4. 4
 Latest U.S. EPA regulation for CO2 capture3:
 1400 pounds CO2/MW-hour gross for new coal fired power plants
 1000 pounds CO2/MW-hour gross for new natural gas power plants
 Minimum 20% CO2 capture
 EPA’s best system for emission reduction3:
Supercritical pulverized coal unit with partial carbon capture and storage
 Need for 400-1000 pounds CO2 capture from existing and new coal fired power
plants in the US3
A viable post-combustion carbon capture technology needed to meet U.S. emission goals
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
Energy Outlook and Carbon Emissions in the US
3. U.S. Environmental Protection Agency, Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility Generating Units, Part III, 80, (2015)

5. 7
Existing Carbon Capture Technologies
Prof. L.–S. Fan’s Chemical Looping and
Particle Technology Laboratory
Carbon capture efficiency: ~85%
80-100% more than COE without capture4
Amine based carbon capture technology
Pre-combustion capture using oxy-combustion
Post-combustion capture using oxy-combustion
Carbon capture capacity: up to 95%
Cost of electricity (COE): 60% more
than COE without capture54. Dutcher, B., Fan, M. & Russell, ACS Appl. Mater. Interfaces 7, 2137–2148 (2015)
5. Oxy-combustion pre-/post-combustion CO2 capture

6. 8
Pre-combustion CO2 capture using calcium looping
process
Pre-combustion CO2, H2S, HX capture6
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

7. 9
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
Post-combustion CO2 capture using calcium looping
process
6. Wang, W. et al. Ind. Eng. Chem. Res. 49, 5094–5101 (2010)
120 KWth subpilot demonsration of CCR
process
>90% CO2 and ~100% SO2 capture
With Ca(OH)2 based sorbent, Ca:C : 1.43

8. 10
Limitations of two-step calcium looping process
Wt.capture%(gCO2/gCaO)
Time (min)
 Maintaining sorbent reactivity and
recyclability
 Minimizing solid circulation rates
 Loss of reactivity due to ‘sintering’ effect
on the sorbents
 Sorbent regeneration is essential to
maintain CO2 capture capacity at 50-60
wt. %.
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
Fig.: Loss of reactivity during multiple CCR cycles for PG
Graymont limestone tested in Pyris1 TGA at 700oC
calcination 30 min and carbonation under 10% CO2
7
60 wt.%
22 wt.%
7. Fu-Chen Yu, Nihar Phalak, Zhenchao Sun, and Liang-Shih Fan, Industrial Chemical
Engineering Resources, 2012, 2133-2142

9. 11
Reactivation of calcium oxide(CaO) Sorbents
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
• Derived from calcium acetate, calcium
propioniate, calcium D-gluconate
• PCC sorbent used in OSCAR process8
Synthesis of
calcium based
sorbents from
different
precursors
• Zr, Si, Ti, Cr, Co, Ce doped9
• Natural dolomitic limestone (CaO-MgO)
Doped or
supported calcium
oxides
• High temperature steam reactivation7
• Water hydration
Steam hydration
reactivation of
calcium oxide
sorbents
8. Fan, L.-S. & Jadhav, R. A. AIChE J. 48, 2115–2123 (2002)
9. Li, Z., Cai, N., Huang, Y. & Han, H. Energy & Fuels 19, 1447–1452 (2005)
7. Yu F.-C., Phalak N., Sun, Z., and Fan, L.-S., Ind Chem Eng Res, 2012, 2133-2142

10. 12
Steam hydration reactivation
HyPr-RING Process10
 CaO + H2O Ca(OH)2 ∆Ho= -109 KJ/mol
 Steam hydration was first in proposed for flue gas
desulfurization (FGD) process
 Used in H2 Production-RING process for hydrogen
production
 Steam hydration was also used in CO2 acceptor
process11
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
10. Lin, S. Y., Suzuki, Y., Hatano, H. & Harada, M. Energy Conversion
Management 43, 1283–1290 (2002) 11. Curran, G. P., Rice, C. H. & Gorin, E. Carbon Dioxide Acceptor Gasification Process

11. 13
 What operating conditions should be used for steam
hydration reactivation of sorbents?
 How can the exothermic hydration reaction be
integrated into the existing two step carbonation
calcination process?
 What residence times should be used for hydration?
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

12. 14
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
490 500 510 520 530 540 550
PH2O(atm)
Temperature (oC)
CaO + H2O Ca(OH)2
P*
H2O = 0.88
P*
H2O = 1.064
P*
H2O = 1.28
P*
H2O = 1.53
High temperature high pressure steam hydration
Reaction Properties
 Steam hydration of CaO is
thermodynamically limited reaction
 Rate α (PH2O – P*
H2O)n
 Easily reversible at T>350oC with no
steam contact
 Thus Ca(OH)2 is directly sent to the
carbonator
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

13. 15
 Steam hydration for PH2O < 1 atm, rate of hydration is slow if operated too close
to equilibrium steam partial pressure
 Wang et al investigated effect of Japanese limestones for steam partial
pressures between 13-23 atm 12. Wang, Y., Lin, S. & Suzuki, Y. Fuel Process. Technol. 89, 220–226 (2008)
 Lin et al13 performed steam hydration at high temperatures 500-650oC and steam
partial pressures 6.7-21 atm
 Rate of hydration α (PH2O – P*
H2O)2
 Second order reaction at high temperature and steam pressure
 Activation energy: 8.4 KJ/mol of CaO
High temperature high pressure steam hydration
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
13. Lin, S., Harada, M., Suzuki, Y. & Hatano, H. Energy and Fuels 20, 903–908 (2006)

14. 16
Steam hydration reactivation studies at OSU
 Three step CCR process includes steam hydration at atmospheric steam
pressure and temperature 475-512oC
 ASPEN process simulations of the CCR process retrofit to a 500 MWe unit with
subcritical PC boiler recommends high temperature-moderate pressure steam
reactivation12 12. Wang, W., Ramkumar, S., Wong, D. & Fan, L.-S. Fuel 92, 94–106 (2012)
 This study investigates reaction kinetics using
 Intermediate reaction temperatures: 500-550oC
 Elevated steam pressures: 1 to 4.5 atm
 Effect of origin of the sorbent on reactivity towards steam
 Effect of sorbent morphology on steam hydration reactivation
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

15. 17
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
Investigation of high temperature – high
pressure steam hydration was performed
using following type of experimental
methods and design

16. 18
Limestone Precursors and Sorbent Properties
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
%CaCO3
%Ca(OH)2
0
10
20
30
40
50
60
70
80
90
100
PG FL EA AA
%CaCO3 %Ca(OH)2
 Calcination performed in Fisher Scientific Muffle Furnace
 Calcination performed at 900oC for 2 hours
 Preliminary analysis of limestone sorbents performed on Pyris 1
TGA
 Weight loss during isothermal decomposition to calculate extent
of calcination and hydration
 %CaCO3 =
W0 – Wcalcined MCaCO3
W0 MCO2
 %Ca(OH)2 =
W0 – W1 MCa
OH
2
W0 MH2O

17. 20
Nitrogen physisorption studies
 Braunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH)
method used to obtain surface area and pore volume of the sorbents
 Sorbents were used in four conditions: original (mostly CaCO3),
calcined sorbent (c-CaO), hydrated sorbent (mostly Ca(OH)2),
hydrated sorbents degassed at 400oC (h-CaO)
 Degassing was performed at 200-400oC under vacuum for atleast 8
hours to obtain a clean and moisture free surface for analysis
 Analysis was performed using N2 adsorption-desorption in liquid
nitrogen bath (-196oC)
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

18. 21
Experimental design and type of reactor
 Parametric steam hydration studies performed
using high pressure in the TGA
 Rubotherm Magnetic Suspension Balance (MSB)
was used for this purpose
 System pressurized using back pressure
regulator under elevated pressures (1-4.5 atm)
 Steam injection using a preheater section before
the reactor
 Water delivered to the preheater using a high
precision syringe pump
 All tests performed on PG sorbent
 Calcination temperature: 700oC
 Inert atmosphere for calcination
 50% steam – 50% N2 for hydration
 Sample size: 120-150 mg
Thermogravimetric analysis
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

19. 22
Fixed Bed Experimental Setup
Experimental design and type of reactor
 Ceramic tube reactor system with quartz
container
 Heated using tubular electric furnace MTI
Corporation GLX 1000
 Air-CO2 mixture was used for calcination of
sorbents to simulate equilibrium conditions for
calcination
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

20. 23
Results and Discussions
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
Characterization and
reactivity studies of
different limestone
sorbents
Reaction kinetics
studies in the TGA for
PG sorbent
Kinetics of steam
hydration at elevated
pressures and
temperatures
Effect of upstream
calcination conditions
on sorbent
morphology
Results and
Discussions

21. 24
BET Surface area and pore volume studies using liquid nitrogen
0
0.05
0.1
0.15
0.2
0.25
Original c-CaO Hydrated
Degassed
150C
h-CaO
(Degassed
400C)
POREVOLUME(ccg-1)
PG FL EA AA
Original – CaCO3 rich limestone sample
c-CaO – Sorbent obtained from calcination in muffle
furnace (CaCO3 = CaO + CO2)
Hydrated – Ca(OH)2 from water hydration of c-CaO
h-CaO – Sorbent derived by dehydration
0
10
20
30
40
50
60
70
80
90
100
Original c-CaO Hydrated
Degassed
150C
h-CaO
(Degassed
400C)
SurfaceArea(m2g-1)
FL PG AA EA
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

22. 25
Reaction Kinetics Studies in the TGA
Temperature
(oC)
Steam pressure (PH2O)
(atm)
500 1.5, 2.0, 2.25, 2.5
510 2.25
520 2.0, 2.25, 2.5, 3.0, 3.5
530 2.0, 2.2, 2.4, 2.6, 2.8, 3.0
Experimental design and reaction conditions
 Rubotherm Magnetic Suspension Balance (MSB)
was used for this purpose
 Reactions conditions based on the process
simulations of the CCR process
 Reaction temperature comparable to carbonator
 With moderate steam partial pressures, higher
hydration conversion observed at each operating
condition
 Reaction time 2 – 12 minutes
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

23. 26
Effect of temperature
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 1 2 3 4 5 6 7 8 9 10
Conversion(X)
Time (minute)
PH2O = 2.0 atm
500 degC 520 degC 530 degC
 PG sorbent
 Steam partial pressure: 2.0 atm
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
1.22
0.72
0.47
0
0.2
0.4
0.6
0.8
1
1.2
1.4
490 500 510 520 530 540
(PH2O–P*H2O)(atm)
TRxn(oC)

24. 27
Effect of temperature
 PG sorbent
 Steam partial pressure: 2.2 – 2.4 atm
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 1 2 3 4 5 6 7 8
X(%) Time (minute)
PH2O = 2.2-2.4 atm
500 degC 520 degC 530 degC 2.2 atm 510 degC
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
1.37
1.19
0.97
0.67
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
490 500 510 520 530 540
(PH2O–P*H2O)(atm)
TRxn (oC)

25. 28
Effect of temperature
 PG sorbent
 Steam partial pressure: 2.5 atm
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 1 2 3 4 5 6 7 8
Conversion(X)
time (minute)
PH2O = 2.5 atm
500 degC 520 degC 530 degC
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
1.62
1.22
0.97
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
490 500 510 520 530 540
(PH2O–P*H2O)(atm)
TRxn (oC)

26. 29
Effect of Steam Partial Pressure
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 1 2 3 4 5 6 7 8 9X(%)
time (minute)
Trxn = 500oC
1.5 atm 2.0 atm 2.5 atm
 PG sorbent
 Reaction temperature: 500oC
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
0.62
1.12
1.62
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1 1.5 2 2.5 3
(PH2O–P*H2O)(atm)
PH2O (atm)

27. 30
Effect of Steam Partial Pressure
 PG sorbent
 Reaction temperature: 520oC
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 1 2 3 4 5
X(%)
Time (minute)
Trxn = 520oC
2.5 atm 2.25 atm 2.0 atm 3.5 atm 3.0 atm
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
0.72
0.97
1.22
1.72
1.97
0
0.5
1
1.5
2
2.5
1.5 2 2.5 3 3.5 4
(PH2O–P*H2O)(atm)
PH2O (atm)

28. 31
Effect of Steam Partial Pressure
 PG sorbent
 Reaction temperature: 530oC
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 1 2 3 4 5 6 7 8 9
X(%)
time (minute)
TRXN = 530oC
3.0 atm 2.8 atm 2.6 atm 2.4 atm 2.2 atm 2.0 atm
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory
0.47
0.67
0.87
1.07
1.27
1.47
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.5 2 2.5 3 3.5
(PH2O–P*H2O)(atm)
PH2O (atm)

29. 32
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0 0.5 1 1.5 2 2.5Rate(s-1)
PH2O - P*
H2O
Rate V/s Delta P @500degC Rate V/s Delta P @520degC
Rate V/s deltaP @ 530 degC
Kinetics of Steam Hydration
 Rate of reaction is proportional to
(PH2O – P*
H2O)n
 n=
(𝑙𝑜𝑔(−𝑟a1) – 𝑙𝑜𝑔(−𝑟a2))
(𝑙𝑜𝑔(𝑃H2O – 𝑃∗
H2O)1 − 𝑙𝑜𝑔(𝑃H2O – 𝑃∗
H2O)2)
 Thus rate α (PH2O – P*
H2O)2
 Order of reaction ~ 2
 k =
−𝑟a
𝑃H2O – 𝑃∗H2O
2 ….Rate constant
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

30. 33
Rate constants and Activation Energy
 k = 𝐴 ∗ 𝑒𝑥𝑝(−𝐸𝑎/𝑅𝑇) =
−ra
(PH2O – P∗
H2O)2
 Arrhenius plot for rate constants
for steam hydration
 Rate constant (k) calculated for
reaction performed at different
steam pressures at different
temperatures
 Ea = 5.19 KJ/mol
0.00E+00
2.00E-05
4.00E-05
6.00E-05
8.00E-05
1.00E-04
1.88E-03 1.92E-03 1.96E-03 2.00E-03
rate constant V/s 1/T Linear (rate constant V/s 1/T)
A = 0.0002 s-1 MPa-1
Ea = 5.19 kJ/mol
Rate constant (k)
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

31. 34
Comparative TGA studies of sorbents
 Steam hydration of sorbents at PH2O =
1.5 atm and Temperature: 500oC
 PG sorbent shows better reactivity
compared to FL, EA, and AA
 PG has the highest surface area in
calcined form (c-CaO)
 Rate of hydration:
PG > FL > EA > AA
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Conversion(X) Time (minute)
PG FL EA AA
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

32. 35
PG Fixed
bed
calcination
Air (ml/min) CO2
(ml/min)
Extent of
calcination
700oC 300 0 67.7%
800oC 240 60 76.5%
900oC 0 300 84.3%
FB 700 degC FB 800 degC FB 900 degC
Surface area (m2/g) 11.698 5.726 1.682
Pore Volume (cc/g) 0.089 0.019 0.005
0.00E+00
1.00E-02
2.00E-02
3.00E-02
4.00E-02
5.00E-02
6.00E-02
7.00E-02
8.00E-02
9.00E-02
1.00E-01
0
2
4
6
8
10
12
14
PoreVolume(ccg-1)
Surfacearea(m2g-1)
Effect of upstream calcination on sorbent morphology
Calcination performed in fixed bed
reactor using Air-CO2 mixture to
simulate equilibrium conditions
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

33. 36
 Rate of steam hydration increases with
increasing steam partial pressure
 Higher conversions can be obtained using
relatively high reaction temperature (500 -
530oC) and moderate steam partial
pressures (1.5-3.5 atm)
 Residence time for hydration in the TGA is
2 to 10 minutes for PG limestone
 Second order reaction w.r.t steam partial
pressure (PH2O – P*H2O)
 Temperature could be increased further to
550-570oC and higher steam pressure 4.5-
5.0 atm for operation in the pre-combustion
CO2 capture process
 Activation energy for the reaction is 5.19
KJ/mol
 Better hydrator design with the available
kinetics data, Ca:C mole ratio could be
minimized with minimization of solids
circulation rate and requirement of make-up
solids
Concluding Remarks
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

34. 37
 Continuous multi-cyclic fixed bed reactor
studies using steam hydration at high
temperature and elevated steam pressure
 Steam conversion and sorbent
performance can be analyzed
 CO2 capture capacity will be obtained for
during carbonation in each cycle in the 15-20
cycle fixed bed studies
 Heat recovery and utility from the exothermic
hydration reaction at high temperature will be
studied using ASPEN simulations of the
CCR process
 Ca:C mole ratio will be obtained for current
U.S EPA regulations for minimum 20% CO2
capture
 Shrinking core model prediction for steam
hydration of CaO could be investigated using
characterization techniques like depth
profiling using XPS or SIMS techniques
Future Work
Prof. L.–S. Fan’s Clean Energy Conversion Laboratory

35. 38
Prof. L.–S. Fan’s Chemical Looping and
Particle Technology Laboratory
Acknowledgements
We are grateful to Ohio Coal Research Consortium (OCRC) for their continuing financial support for clean coal
conversion research projects including this.