accelerated reaction-driven carbon storage: insights...

November 28, 2017

National Academy of Science Workshop on Geologic Capture and Sequestration of Carbon

Stanford University, Palo Alto, CA

Accelerated reaction-driven carbon storage:Insights from laboratory-scale studies for field-scale geologic carbon storage

Department of Civil and Environmental Engineering Environmental Chemistry & Technology Program

Geological Engineering Program Wisconsin Energy Institute

University of Wisconsin, Madison

Greeshma Gadikota

Gadikota and Park, 2014, inCarbon Dioxide Utilization: Closing the Carbon Cycle

Contributions from Peter Kelemen, Columbia University & Greg Dipple, University of British Columbia

2

Carbon Mineralization at the Field Scale

http://gwsgroup.princeton.edu/SchererGroup/Salt_Crystallization.html

3

CO2 Trapping Mechanisms

Contribution to CO2Storage Security

Solubility Trapping Positive – CO2 stored as fluid

Mineral Trapping Positive – CO2 stored as solid

Mineral Trapping with Reactive Cracking

Facilitates CO2dispersion - reduces pressure build-up but increases CO2 leakage potential

CO2 Storage in Geologic Reservoirs

Uncertainties in the time scales of carbon mineralization exist

4

Worldwide Availability of Ca- and Mg-bearing Minerals and Rocks

Belvidere Mountain, VermontSerpentine Tailings

Mineral Carbonation of Peridotite

Photo by Dr. Jürg Matter at LDEO (2008)

The most permanent method of carbon storage

Exothermic transformation Thermodynamically stable product Long-term environmentally benign

and unmonitored storage

5

Direct versus Two-Step Conversion to Carbonates

Gadikota and Park, 2014, Carbon Dioxide Utilization, 1st Edition, Elsevier

6

Reactivity of Ca- and Mg-bearing Minerals and Rocks and Implications for Carbon Storage

Magnetite Anorthite Basalt Talc Augite Lizardite Antigorite Fayalite Forsterite Wollastonite 0

20

40

60

80

100

Exte

nt o

f Car

bona

tion

(%)

Experiments performed at 185oC, PCO2 of 150 atm in 1.0M NaCl+0.64M NaHCO3. 15 wt. % solidReaction time:

Abundance of less reactiveminerals vs. limited availabilityof highly reactive minerals

1 hr0.5 hr 4 hr

4 hr dry attrition grindingAll others – 1 hour dry attrition grinding

Carbonation efficiency defineswhether mineral is utilized forex-situ or in-situ storage

Ex-situ CO2Storage

In-Situ CO2Storage

Shorter time scales (~hours)

Longer time scales (~years)

Limited spatial scale Larger spatial scale with utilization of earth as a reactor (~hundreds of miles)

Relativelyhomogenous mineralogy

Heterogeneous mineralogy

More flexible tuning in reaction conditions

Possible production of value-added products

No monitoring required

Not limited by reactor size; Use of geothermal gradient

Multiple CO2trappingmechanisms

Relatively economical at this time

O’Connor et al., AAPG Annual Meeting, 2003

Silicates Alumino-silicates

Fe3O

4

CaA

l 2Si 2O

8

rock

mix

ture

Mg 3

Si 4O

10(O

H) 2

Ca(

Mg,

Fe)S

i 2O6

Mg3Si2O5(OH)4

Fe2S

iO4

Mg2SiO4

CaSiO3

7

Role of Carbon Mineralization in Enabling Geologic Carbon Storage

To develop a comprehensive understanding of CO2 mineralization behavior and its implications for CO2 storage potential

Comparison of dissolution rates and direct mineralization rates

Determination of the feedback mechanisms due to chemo -morphological - mechanical changes

Evaluation of the impacts on CO2 storage potential and net CO2

emission reductions & costs

• Develop thermodynamically downhill routes for permanent CO2storage with reduced monitoring needs

8

Better Design of Kinetic Studies

Gadikota et al., I&ECR, 2014

9

Laboratory Scale Dissolution Rates: Novel Reactor Designs to Probe Surface and Bulk Dissolution

Variations in surface dissolution vs. bulk dissolution rates observed in serpentine ((Mg,Fe)3Si2O5(OH)4)

Custom-built Differential Bed Reactor to Determine Surface and Bulk Dissolution Rates


10

Better Design of Kinetic Studies


11

Minerals and Rocks of Interest

Analyte Olivine(wt%)

((Mg,Fe)2SiO4)

Labradorite(wt%)

((Ca,Na)(Al, Si)4O8)

Anorthosite(wt%)

Basalt(wt%)

CaO 0.16 10.20 14.10 8.15MgO 47.30 0.24 8.74 4.82Fe2O3 13.90 0.97 10.60 14.60SiO2 39.70 54.30 41.80 51.90Al2O3 0.20 28.00 24.20 13.40Na2O 0.01 5.05 0.59 2.91Carbonation Potential, (assuming that Fe does not react to form FeCO3)

0.343 0.171 0.105 0.076

Carbonation Potential, (assuming that Fe reacts to form FeCO3)

0.374 0.206 0.157 0.081

Mg#1 87 - 66 48An#2 - 53 98 60

Anorthosite comprised 63% anorthite (CaAl2Si2O8), 14% forsterite (Mg2SiO4), 10% fayalite (Fe2SiO4), and 3% albite (NaAlSi3O8), and diopside (MgCaSi2O6)Basalt comprised 20% anorthite, 25% albite, 8% diopside, 8% enstatite (MgSiO3)

I (single mineral)

II (minerals and mixture rocks)

12

Chemo-Morphological Coupling during Carbon Mineralization:Effect of Reaction Temperature on Olivine Carbonation

1 10 100 10000

2

4

6

8

10

Volu

me

(%)

Particle Diameter (m)

1 10 100

10-4

10-3

10-2

Cum

ulat

ive

Pore

Vol

ume

(ml/g

)

Pore Diameter (nm)

Unreacted Olivine 90 oC 125 oC 150 oC 185 oC

80 100 120 140 160 180 2000

20

40

60

80

100

Ext

ent o

f Car

bona

tion

(%)

Temperature (oC)

TGA TCA ARC [1 hr]

Experimental Conditions: PCO2 = 139 atm, 3 hrs, 1.0 M NaCl + 0.64 M NaHCO3, 15 wt% solid, 800 rpm

Gadikota et al., 2014, Physical Chemistry Chemical Physics

Temperatures > 150oC are needed to achieve high conversions via direct carbonation

Carbonate formation increases the particle size and reduces porosityC

umul

ativ

e In

tern

al V

oid

Vol

ume

(ml/g

)

13

Chemo-Morphological Coupling during Carbon Mineralization:Effect of Solution Composition on Olivine Carbonation

0.0 0.5 1.0 1.5 2.0 2.50

20

40

60

80

100

Ext

ent o

f Car

bona

tion

(%)

[NaHCO3] (M)

TGA TCA ASU [1 hr]

1 10 100 10000

2

4

6

8

10

Volu

me

(%)


Unreacted D.I.Water 0.32 M 0.48 M 0.64 M 1.00 M 2.00 M

1 10 100

10-4

10-3

10-2

Unreacted D.I.Water 0.32 M 0.48 M 0.64 M 1.00 M 2.00 MC

umul

ativ

e P

ore

Volu

me

(ml/g

)

Pore Diameter (nm)

0.0 0.5 1.0 1.5 2.010-6

10-5

10-4

10-3

10-2

10-1

Con

cent

ratio

n (m

ol/k

g)[NaHCO3] (M)

Mg-equilibrium Carbonate - equilibrium

(b)

Experimental Conditions: 185 oC, PCO2 = 139 atm, 3 hours, 15 wt% solid, 800 rpm

Speciation calculations show that NaHCO3 buffers pH (6.4 – 7.0).

Buffering the pH in the range of 6 – 7 facilitates dissolution and carbonation.

Progressive growth of carbonates reduces overall porosity and increases particle size.

Cum

ulat

ive

Inte

rnal

Voi

d V

olum

e (m

l/g)

14

Formation of Anhydrous MgCO3 at Lower Temperatures

20 30 40 50 60 70 80

2

Unreacted

90oC

125oC

185oC

150oC

Rel

ativ

e In

tens

ity

MagnesiteOlivine

Dominant formation of magnesite (MgCO3)

Hydrous phases such as nesquehonite (MgCO3.3H2O) and hydromagnesite (Mg5(CO3)4(OH)2·4H2O) were not formed in the range of 90-185 oC

I

II

15

Direct Carbon Mineralization: Compositional Effects

0.5 h

1.0 h 6.0 h

5.0 h

Reaction time

* this study

alumino-silicate bearing mineralsor rocks

silicate bearing minerals

Gadikota et al., in progress

Experimental Conditions: 185 oC, PCO2 = 139 atm in 1.0 M NaCl + 0.64 M NaHCO3, 15 wt% solid, 800 rpm

Rapid passivation in labradorite, anorthositeand basalt limit extent of carbonation …

but not for olivine!

Direct Carbon Mineralization: Effect of Passivation on Carbon Mineralization

16

Direct Carbon Mineralization: Effect of Reaction Time on Olivine Carbonation

Olivine carbonation is well-

modeled as exhaustion of the

remaining reactant at a

constant rate.

Experimental Conditions: 185 oC, PCO2 = 139 bars

1.0 M NaCl + 0.64 M NaHCO3, 15 wt% solid, 800 rpm

Ext

ent o

f Car

bona

tion

(%)

time (hours)17

18

Comparison of Direct Mineralization Rates with Dissolution Rates:Olivine ((Mg, Fe)2SiO4)

Experimental conditions for carbonation experiments :Minerals and rocks1-3 hours, 1.0 M NaCl + 0.64 M NaHCO3

Direct olivine carbon mineralization rates at higher CO2 partial pressures

are an order of magnitude greater compared to measured dissolution rates.

vertical and horizontal ranges

are constanton next several

plots of temperatureversus rate

0 to 250°C

10-13 to 10-2 mol/(m2 s)

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

19

Direct Carbon Mineralization Rates:Comparison of Ca- and Mg-bearing Mineral and Rocks with Mine Tailings

Experimental conditions for carbonation experiments :Minerals and rocks 3 hours, 1.0 M NaCl + 0.64 M NaHCO3

Olivine carbon mineralization rates at higher CO2 partial pressures

are two orders of magnitude greater than carbon mineralization rates for other

common rocks and minerals.

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

20

Comparison of Direct Mineralization Rates with Dissolution Rates:Brucite (Mg(OH)2) and Serpentine ((Mg, Fe)3Si2O5(OH)4)

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

Among peridotite alteration minerals, brucite dissolution is faster than olivine at lowtemperature, while serpentine minerals (chrysotile, lizardite) are much slower

21

Comparison of Dissolution Rates:Anorthite, Labradorite, Basalt, and Basaltic Glass vs Olivine

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

With the exception of amorphous basalticglass, olivine dissolution rates attemperature > 50°C are much faster thanfor basalt and alumino-silicate mineralssuch as plagioclase (anorthite, bytownite,labradorite, andesine)

22

Comparison of Dissolution and Carbonation Ratesat Low Temperature with Elevated CO2

Brucite dissolves and carbonates faster than olivine

High PCO2 increases dissolution and carbonation rates

Rea

ctio

n R

ate

(mol

/(m2 .s

)

CO2 Partial Pressure (bars)

23

Olivine Carbonation Kinetics over Similar Temperature Ranges

Experimental conditions for carbonation experiments :Minerals and rocks1-3 hours, 1.0 M NaCl + 0.64 M NaHCO3

Rea

ctio

n R

ate

(mol

/(m2 .s

)

1/T (K-1)

24

Olivine Dissolution Kinetics and Rate Laws

Our rate law:

Hanchen’s rate law: )(76.6362

46.022, )(0854.0)./( KT

disMg eHscmmolr

))(

20425.2(5.0

))(

20421.0(2

1, 10003.0)(10)./( KTKTdisMg Hscmmolr

Mg (

aq):S

i (aq)

time (minutes)

Ea = 52.9 kJ/mol

Ea = 31 kJ/mol

log

(r)

1/T (K-1)

pH: 3.0

Magnesite Precipitation Rate:(Saldi et al., 2012)

)1()()./(33

23

32,

MMg

M

OHCOOHCOCOOH

OHCOMgprecipMg aKKKaK

KKkscmmolr

25

Incorporating the Morphological Changes in the Kinetic Model

Temperature conditions chosen based on the single step carbonation rate data (Gadikota, PCCP 2014)

Assume changing volume of rock due to surface passivation: n <0, increasing surfaces available (e.g., through fractures): n> 0 no changes: n = 0

Simulations set up in PhreeqC (geochemistry software)

90 oC(Low)

125 oC(Medium)

150 oC(High)

n

time

time

time

time

VV

RateRate

00

26

Carbonate Conversion Predictions Based on the Rate Data

T (oC) rMg,dis1, t = 0(mol/m2.s)

90 2.1 x 10-12

125 6.5 x 10-12

150 1.3 x 10-11


90 1.4 x 10-11

125 6.7 x 10-11

150 1.7 x 10-10

Our work

Hanchen et al., 2006

(a)

(b)

Carbonation rates are highly sensitive to the temperature, rates of dissolution, and assumptions of changes in the morphology of the rocks

Rates that are greater by an order of magnitude predict complete carbonation by a time difference of a decade

=> There is a critical need to constrain rates of mineral dissolution, carbonate precipitation, and coupled dissolution and precipitation behaviors

27


To develop a comprehensive understanding of CO2 mineralization behavior and its implications for CO2 storage potential and costs






28

What is the Impact on Net CO2 Emissions if Olivine is Reacted at 25 oC vs. 155 oC?

25 oC 155 oC

Kirchofer et al., Energy & Envr. Sci., 2012

Experimental evidence of higher olivine carbonation kinetics at elevated temperatures

translates into overall gains in reduced CO2 emissions.

29

What is the Carbon Storage Potential via Ex-situ Mineralization Approaches?


Natural alkalinity sources ‘‘a’’ assumes a production rate of 18 Mt per year, equivalent to U.S. lime production, and ‘‘b’’ of 760 Mt per year, equivalent to U.S. sand and gravel production

Carbon mineralization contributes to the portfolio of options

available for reliable carbon storage.

30

Opportunities and Challenges in Accelerated Carbonate Formationfor Industrial Decarbonization

Gadikota et al., 2015, Advances in CO2 Capture, Sequestration, and Conversion

Gadikota et al., 2014, Journal of Hazardous Materials

Control20% SiO210% cSSS


Variable compositions of industrial wastescan complicate the development of consistentprocesses

May need high temperatures and pressuresto achieve reasonable conversions

Incorporate these materials into constructionmaterials

Safe for landfilling due to reduced alkalinity

31

Opportunities in Accelerated Carbonate Formationfor Industrial Decarbonization: Synthesis of High-Value Products

Gadikota and Park, 2014, Carbon Dioxide Utilization, Elsevier

Achieving high degree of control over desired chemical and morphological composition for CO2 utilization remains a challenge


32

Preliminary Estimated Costs

Storage approach US$/ton CO2

Geologic carbon storage* 0.5 - 8

Geologic carbon storage: monitoring and storage*

0.1 - 0.3

Mineral carbonation* 50 – 100*

Mine tailings carbonation with co-production of value-added commodities (Ni)

10 - 60

Grinding and milling ~ $10/ton of rockChemical processing cost ~ varies from $ 10 - $ 50/ton of rock (path dependent)Cost estimates for mineral carbonation ~ $ 20 - $ 60

Offsets for costs include the production of value-added materials ~ $ 5 - $15/tonFeasible range for mineral carbonation: $ 5 - $ 45/ton

*IPCC special report on carbon capture and storage, 2005

33

Conclusions and Summary

Development of consistent experimental methodologies has led to an improved understanding of carbon mineralization rates.

Significant variations in predicted mineralization rates translate into field scale uncertainties in monitoring costs.

Mineralization rates are accelerated at higher temperatures and high pCO2in situ carbon mineralization achieves high T and P at low cost ex situ potential for utilizing industrial waste heat may offset energy costsco-production of energy and useful commodities may offset overall costs

Advanced mineralization approaches have the potential to be used in industrial decarbonization in addition to enabling clean fossil energy production.

34

Acknowledgments

Geo-Chemo-Mechanical Studies for Permanent CO2 Storage in Geologic Reservoirs

NSF Research Coordination NetworkCarbon Capture, Utilization & Storage

Accelerated CO2 conversion to carbonates

Peter Kelemen and Alissa Park, Columbia University

Greg Dipple, University of British Columbia

Funding Sources

35

Questions?

36

Laboratory Scale Dissolution Rates: Novel Reactor Designs to Probe Surface and Bulk Dissolution

Variations in surface dissolution vs. bulk dissolution rates observed in serpentine ((Mg,Fe)3Si2O5(OH)4)

Gadikota et al., 2014, Industrial and Engineering Chemistry Research

Custom-built Differential Bed Reactor to Determine Surface and Bulk Dissolution Rates

37

Chemo-Morphological Coupling during Carbon Mineralization:Effect of Reaction Temperature on Olivine Carbonation

1 10 100 10000

2

4

6

8

10

Volu

me

(%)


1 10 100

10-4

10-3

10-2

Pore Diameter (nm)

Unreacted Olivine 90 oC 125 oC 150 oC 185 oC

80 100 120 140 160 180 2000

20

40

60

80

100

Ext

ent o

f Car

bona

tion

(%)

Temperature (oC)

TGA TCA ARC [1 hr]

Experimental Conditions: PCO2 = 139 atm, 3 hrs, 1.0 M NaCl + 0.64 M NaHCO3, 15 wt% solid, 800 rpm

Gadikota et al., 2014, Physical Chemistry Chemical Physics

Temperatures > 150oC are needed to achieve high conversions via direct carbonation

Carbonate formation increases the particle size and reduces porosity

Cum

ulat

ive

Inte

rnal

Voi

d V

olum

e (m

l/g)

38

Chemo-Morphological Coupling during Carbon Mineralization:Effect of Solution Composition on Olivine Carbonation

0.0 0.5 1.0 1.5 2.0 2.50

20

40

60

80

100

Ext

ent o

f Car

bona

tion

(%)

[NaHCO3] (M)

TGA TCA ASU [1 hr]

1 10 100 10000

2

4

6

8

10

Volu

me

(%)



1 10 100

10-4

10-3

10-2


Pore Diameter (nm)

0.0 0.5 1.0 1.5 2.010-6

10-5

10-4

10-3

10-2

10-1

Con

cent

ratio

n (m

ol/k

g)[NaHCO3] (M)

Mg-equilibrium Carbonate - equilibrium

(b)

Experimental Conditions: 185 oC, PCO2 = 139 atm, 3 hours, 15 wt% solid, 800 rpm

Speciation calculations show that NaHCO3 buffers pH (6.4 – 7.0)

Buffering the pH in the range of 6 – 7 facilitates dissolution and carbonation

Progressive growth of carbonates reduces overall porosity and increases particle size

Cum

ulat

ive

Inte

rnal

Voi

d V

olum

e (m

l/g)

39

Formation of anhydrous MgCO3 at lower temperatures

20 30 40 50 60 70 80

2

Unreacted

90oC

125oC

185oC

150oC

Rel

ativ

e In

tens

ity

MagnesiteOlivine

Dominant formation of magnesite (MgCO3)

Hydrous phases such as nesquehonite (MgCO3.3H2O) and hydromagnesite (Mg5(CO3)4(OH)2·4H2O) were not formed in the range of 90-185 oC

I

II

40

Direct Carbon Mineralization Rates:Comparison of Ca- and Mg-bearing Mineral and Rocks with Mine Tailings

100% 50%

10%

0.04%

Brucite mine tailings(vol % CO2 at 1 atm)

Experimental conditions :Minerals and rocks: 185 oC, PCO2 = 139 atm, 3 hours, 1.0 M NaCl + 0.64 M NaHCO3Brucite (Mg(OH)2) mine tailings: ambient temperature, reaction time > 70 hours (Harrison et al., ES&T, 2013)

*Rate data normalized to BET surface area

41

Comparison of Direct Mineralization Rates with Dissolution Rates:Olivine ((Mg, Fe)2SiO4)

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

*Rate data normalized to geometric surface area

Direct olivine carbon mineralization rates at higher CO2 partial pressures

are an order of magnitude greater compared to measured dissolution rates.

42

Comparison of Direct Mineralization Rates with Dissolution Rates:Brucite (Mg(OH)2) and Serpentine ((Mg, Fe)3Si2O5(OH)4)

Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

(100 vol% CO2)( 50 vol% CO2)( 10 vol% CO2)

( 4 vol%)

direct mineralization rates of brucite bearing mine tailings


At low CO2 concentrations (~4 vol. %), direct mineralization rates of brucite mine tailingsare comparable with dissolution rates. Reaction rates increases with CO2 concentrations.

43

Comparison of Direct Mineralization Rates with Dissolution Rates:Anorthite, Labradorite, and Basalt


Rea

ctio

n R

ate

(mol

/(m2 .s

)

Temperature (oC)

Shaded region represents direct mineralization rates of labradorite, anorthite, and basalt

Direct mineralization rates are 1-2 orders of magnitude higher compared to dissolution rates of anorthite, labradorite, and basalt

Hypothesis: Continuous removal of carbonate ions in solution to form solid precipitates drives the forward dissolution reaction rate => higher direct mineralization rates

44

Magnesite Formation in Fractured Porous Media: Evidence of Chemo-Morphological-Mechanical Coupling

During Carbon Mineralization

(a) (b)

Evidence of magnesite formation along olivine fractures

45

Rate Data for Predicting the Time Scale of Carbonate Formation

Ea = 52.9 kJ/mol

Ea = 31 kJ/mol

Our rate law:

Hanchen’s rate law:

Magnesite Precipitation Rate:(Saldi et al., 2012)

)(76.6362

46.022, )(0854.0)./( KT

disMg eHscmmolr

)1()()./(33

23

32,

MMg

M

OHCOOHCOCOOH

OHCOMgprecipMg aKKKaK

KKkscmmolr

))(

20425.2(5.0

))(

20421.0(2

1, 10003.0)(10)./( KTKTdisMg Hscmmolr

46

Incorporating the Morphological Changes in the Kinetic Model

Temperature conditions chosen based on the single step carbonation rate data (Gadikota, PCCP 2014)

Assume changing volume of rock due to surface passivation: n <0, increasing surfaces available (e.g., through fractures): n> 0 no changes: n = 0

Simulations set up in PhreeqC (chemistry software)

90 oC(Low)

125 oC(Medium)

150 oC(High)

n

time

time

time

time

VV

RateRate

00

47

Carbonate Conversion Predictions Based on the Rate Data


90 2.1 x 10-12

125 6.5 x 10-12

150 1.3 x 10-11


90 1.4 x 10-11

125 6.7 x 10-11

150 1.7 x 10-10

Our work

Hanchen et al., 2006

(a)

(b)

Carbonation rates are highly sensitive to the temperature, rates of dissolution, and assumptions of changes in the morphology of the rocks

Rates that are greater by an order of magnitude predict complete carbonation by a time difference of a decade

=> There is a critical need to constrain rates of mineral dissolution, carbonate precipitation, and coupled dissolution and precipitation behaviors

48


To develop a comprehensive understanding of CO2 mineralization behavior and its implications for CO2 storage potential and costs






49

What is the impact on net CO2 emissions if olivine is reacted at 25 oC vs. 155 oC?

25 oC 155 oC


Experimental evidence of higher olivine carbonation kinetics at elevated temperatures

translates into overall gains in CO2 emissions reduced.

50

What is the carbon storage potential via ex-situ mineralization approaches?


Natural alkalinity sources ‘‘a’’ assumes a production rate of 18 Mt per year, equivalent to U.S. lime production, and ‘‘b’’ of 760 Mt per year, equivalent to U.S. sand and gravel production

Carbon mineralization contributes to the portfolio of options

available for reliable carbon storage

51

Direct Carbon Mineralization: Compositional Effects

0.5 h1.0 h 6.0 h

5.0 hReaction time

* this study

alumino-silicate bearing minerals or rocks

silicate bearing minerals

In-situ storage potential

Ex-situ storagepotential

Storage approach US$/ton CO2

Geologic carbon storage

0.5 - 8

Geologic carbon storage: monitoring and storage

0.1 - 0.3

Mineral carbonation 50 – 100*

Estimates from IPCC Special Report on Carbon Capture and Storage, 2005

Significant uncertainties exist in reporting costs for carbon mineralization

Potential of using waste heat at a power plant as heating source

Availability of pre-ground mine tailings as low-cost substrates

Potential reuse of industrial acidic and alkaline waste water streams

Tailored use of passive vs. active carbonation approaches

52

Opportunities in Accelerated Carbonate Formationfor Industrial Decarbonization: Synthesis of High-Value Products

Gadikota and Park, 2014, Carbon Dioxide Utilization, Elsevier

Achieving high degree of control over desired chemical and morphological composition for CO2 utilization remains a challenge


53

Conclusions and Summary

Development of consistent experimental methodologies has led to an advanced understanding of carbon mineralization rates.

Significant variations in predicted mineralization rates translates into field scale uncertainties in monitoring costs.

Mineralization rates are accelerated at higher temperatures and in water-rich environments => potential for utilizing industrial waste heat or waste water may result in significant offset of overall energy costs.

Advanced mineralization approaches have the potential to be used in industrial decarbonization in addition to enabling clean fossil energy production.

54

Metastability in MgO-CO2-H2O Systems

Magnesite is the most stable and least soluble carbonate under most conditions (including PCO2)

Despite this, magnesite is seldom the main product reported in literature:- Brucite: Mg(OH)2

- Lansfordite: MgCO3·5H2O

- Nesquehonite: MgCO3·3H2O

- Hydromagnesite: Mg5(CO3)4(OH)2·4H2O

- Magnesite: MgCO3

Driven by reaction kinetics, given enough time, magnesite should form

55

Effect of Temperature on Mg(OH)2 Slurry Carbonation

At 150 ºCMake Hydromagnesite

At 30 ºCMake Nesquehonite

At 200 ºC Make Magnesite

Fricker et al., I&ECR, 2014.

accelerated reaction-driven carbon storage: insights...

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