New Developments in CombustionNew Developments in Combustion TechnologyG A Ri h d Ph DGeo. A. Richards, Ph.D.National Energy Technology Laboratory - U. S. Department of Energy

2012 Princeton-CEFRC Summer School On Combustion2012 Princeton-CEFRC Summer School On CombustionCourse Length: 3 hrsJune 26, 2012

Electric Power Across the Globe

“The single biggest problem we have to focus on in this century is how to get every citizen of earth roughly the same per-capita energy we enjoy in the

developed world.” ― Nathan Myhrvold, former CTO, Microsoft

“The single biggest problem we have to focus on in this century is how to get every citizen of earth roughly the same per-capita energy we enjoy in the

developed world.” ― Nathan Myhrvold, former CTO, Microsoft

2

p yp y

Wall Street Journal, Monday March 7 2011, page R8

Energy Contributes to Quality of Life

UK U.S. Qatar

GDP vs. Energy Consumption100,000

Mexico Bahrain

pita / y

r)

South Africa10,000

CongoPeru

Bulgaria

GD

P pe

r C

ap

US$

/ pe

rson

China

South Africa

1 000Eritrea

(U China

India

1,000

Annual Energy Consumption per Capita(k / / )

100100 1,000 10,000 100,000

3

(kgoe / person / yr)http://www.iea.org/textbase/nppdf/free/2011/key_world_energy_stats.pdf

Research makes a difference!Research makes a difference!The shale gas exampleThe shale gas example

Current R&D is ensuring environmentally sustainable development 

Today’s shale gas resource had it’s start in research more than 30 years ago.

What new ideas in thermal science and of domestic natural gas resources through:

R&D in the early 2000’s developed environmental technology & refined

• Field studies on environmental baselines 

• Leading multi institutional

combustion will shape the future?

technology & refined assessments for: 

• Shale gas• Tight gas• Coal‐bed methane

• Leading multi‐institutional & multi‐organizational research teams at sites

R&D in the ‘70s–’90s provided the technology base to unlock new gas

DOE Eastern/Western Gas Shale Program

base to unlock new gas resources :

• Advanced drilling & completion (e.g., directional drilling, fracturing, stimulation)R i l d k

4

• Resource potential and key properties

Energy and Carbon Dioxide• Carbon dioxide capture and storage – costly, but not required, now.• Carbon dioxide utilization in enhanced oil recovery (EOR) is needed, now.• Carbon dioxide costs from natural source < anthropogenic sources.

Figure 3. Sources of CO2 for Domestic EOR Floods1.McElmo

2 Jackson2010 Domestic EOR CO2 Use*Figure 3.  Sources of CO2 for Domestic EOR Floods

7

2. Jackson

3. Bravo

4. Sheep

5. Doe Canyon

*6. St. John’s

*7. Kevin

*8. Escalante

• 58 million metric tons CO2supplied.

• 85% of the supply is from natural sources

1 458

10

9

1314

15

18 2019

*9. Gordon Creek

10. LaBarge

*11. Century

12. TGRMP

*13. Lost Cabin

*14. Riley Ridge

natural sources.• 13% from natural gas

processing.• 2% from hydrocarbon

i

Natural Sources

2

3

6

1112

1617

18 20

21 24

22

23

25

15. Turtle Lake

16. Koch Nitrogen

17. Agrium, Inc.

18. Conestoga

19. Bonanza Energy

*20. CVR Energy 

processing.

Can we develop efficient & affordable methods to #1 to 9

Natural Gas Processing

Hydrocarbon Conversion

* Not operational in 2010

*21. Air Products

*22. Mississippi  Power

*23. Summit Texas

*24. Leucadia

*25. NRGOil and gas fields

* A typical 550 MW coal plant emits 3.5 million tonne/ year

supply CO2 ?#10 to 15

#16 to 25

5

Graphics and information courtesy Phil DiPeitro – NETL. Reference: DiPietro, J. P., Balash, P., Wallace, M., (2012) .A note on sources of CO2 supply for enhanced-oil recovery operations, http://www.spe.org/ejournals/spe/EEM/2012/04/TechNote_0412.pdf

yp c W co p e s . o o e/ yeCO2;http://www.netl.doe.gov/energyanalyses/refshelf/PubDetails.aspx?Action=View&PubId=348

Post-Combustion CO Capture

Efficiency - 25%(of initial, e.g. 40% efficiency could drop to 30%)

Electric cost + 63%

CO2 Capture

Carbon Dioxide Capture Optionsaverage of published studies*

6

http://www.iea.org/publications/freepublications/publication/name,3950,en.html* Finkenrath, M. (2011), Cost and Performance of Carbon Dioxide Capture from Power Generation

The role of capture AND generator efficiency• A simple• A simple

heat/energy balance defines the overall

Define: = (kg CO2 produced) / (kg fuel burned )CO2 = (separation work, Joules ) / (kg CO2) CO2 the overall

efficiency ov with a carbon separation unit.g

• Reducing the penalty from carbon capture

GeneratorCarbon

Q = mfHFuel Heat

Input

gGeneratorEfficiency

WoGross

Generator

W1Net

Output carbon capture comes from BOTH:

Decreasing

Carbon SeparationUnit

Work

– Decreasing CO2

– Increasing g

7

Approx Ranges: (30 – 60%) (6-10%)

Today’s presentation• New approaches in three ways

– Inherent carbon capture: chemical looping combustion.– Step-change in generator efficiency: pressure gain combustion– Frontier approach (?): making oxy-fuel an efficiency advantageFrontier approach (?): making oxy fuel an efficiency advantage.

8

Today’s presentation• New approaches in three ways

– Inherent carbon capture: chemical looping combustion.– Step change in generator efficiency: pressure gain combustion– Way out: making oxy-fuel an efficiency advantage.Way out: making oxy fuel an efficiency advantage.

Thi t d t f k d b f th U it d St t G tThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, g p y g y p pprocess, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

9

Oxy-fuel backgroundOxy- fuel achieves carbon capture very easily:y p y y

Air-Combustion:CH + 5/4(O2 + 3.8N2) CO2 + 1/2H2O +4.7 N2

Costly to extract the CO2 from the N2 with amines

Oxy-Combustion:CH + 5/4(O2) CO2 + 1/2H2O

Easy to extract the CO2 from the H2O via condensation

“Usual” oxy-fuel approach: oxygen diluted with CO2 or H2O added to an existing boiler cycle.

– Dilution used to keep the temperatures same as Meridosia Illinois Future Gen 2 0 planned siteexisting cycle.

– Efficiency of the plant is penalized by the energy needed to make oxygen.

Meridosia Illinois – Future Gen 2.0 planned site

Significant oxy-fuel demonstration projects are occurring around the world.– See for example: http://www.newcastle.edu.au/project/oxy-fuel-

working-group/demonstrations.html

10

g g p

– More than 10 demos >10MWth listed Courtesy University of Utah – oxyfuel burner tests

Making oxygen for oxy-fuel• Oxygen can be supplied today by commercial Air Separation Units yg pp y y p

(ASU) based on established cryogenic separation.• The energy needed to separate oxygen from air is significant (see

below).• In conventional oxy-combustion, we dilute the purified oxygen to

maintain the same boiler flame temperature as in air-combustion.

Air Separation

Unit

1 mole of air

0.21 moles oxygen pO2= 0.21 atm

0.21 moles oxygen pO2 = 1 atm

0 79 l i

Dilute againwith CO2 or steam

(ASU)0.79 moles nitrogen pN2 = 0.79 atm

0.79 moles nitrogen pN2= 1 atm

Reversible separation work:

C + O2 CO2H ~ G = 394 kJ/gmol (C or O2)p

~6 kJ/gmol O2 produced*

Current actual process:~18kJ/gmol O2 produced**

In efficient powerplants we convert less than ½ of H to work.Thus~200kJ/gmol O2 work produced

Roughly ~1/10 of that is needed for ASU.

11

*e.g, the change in gibbs energy for ideal mixing (Sandler, Chemical Engineering Thermodynamics (1989) pp. 313. **See Trainier et al., “Air Separation Unit…..” Clearwater Coal Conference, 2010.

g y

Chemical Looping• Shares advantages of oxy-fuel

– Product is just CO2 and H2O• No separate oxygen production is needed• Significant interest/development worldwideg p• Schemes for H2 production, carbon capture… CANMET Energy Technology

Center mini pilot-scale sorbent looping test facility.*N2 + O2

(vitiated air)

CO2 + H2O

Seal

Ash

Recycle

Pilot-scale calcium looping rig (30 kW) at INCAR_CSIC, Oviedo, Spain*

120 kW Chemical Looping test rig (TU, Austria) *

CO2 + H2OFuel

Air

Seal

Carbon + metal oxide = CO + metal

12

Carbon + metal oxide = CO2 + metalMetal + air (oxygen) = metal oxide •Photos used with permission from the IEA web-site

for the chemical looping network

Not quite new

• Chemical looping has been around – but for different reasons and applications.

19 4 f CO

CO2

– 1954 patent to manufacture CO2

• Similar process: iron-steam route to hydrogen (circa 1920)*

M

HX

Reduce iron with fuel and oxidize it with steam:

F3O4 + 4 CO 3Fe +4 CO23 O O

Air ReactorM + (O2 + 3.8N2)

MO + 3 8 N

MO2

3 Fe + 4 H2O Fe3O4+ 4H2

“Production of Pure Carbon Dioxide” US Patent 2,665,972 (1954)

MO2 + 3.8 N2Fuel ReactorMO2 + C

CO2 + M

• And, before that….respiration., , ( )

Notice the heat exchangers (HX) in BOTH fuel and air reactors.Should have made it a boiler?Hemoglobin “loops”

to carry oxygen from lungs for hydrocarbon

13

yoxidation in cells. *Hurst, S. (1939). “Production of Hydrogen by the Iron-Steam Method”,

Journal of the American Oil Chemist’s Society, 16 (2), pp. 29-36.

Interesting Comments About CLC (1) “The CO2 Capture Project (CCP) sponsored by Eni, Statoil Hydro, Shell,(1) The CO2 Capture Project (CCP) sponsored by Eni, Statoil Hydro, Shell,

Suncor, BP, Chevron, Petrobas, Conoco Phillips found that: ‘CLC has the potential to become the preferred option” for steam boilers and process heaters…’”

(2) Report by ENhanced CAPture of CO (ENCAP) Ekstrom et al 2009:(2) Report by ENhanced CAPture of CO2 (ENCAP), Ekstrom et al., 2009:

CLC Bit. Relto 445 MWeC f

IGCC Bit. Rel. to 600 MWe w/o

Oxyfuel Bit. Rel. to 600 MW PF

CFB Ref. capt.Energy Penalty 4% 20% 20%CO2 avoided $/ton 8 to 16 23 to 49 17 to 37

Both items above: directly from Henrik Leion and Adel Sarofim, Chemical-Looping Tutorial , The 36th International Technical Conference on Clean Coal & Fuel Systems, June 5-9, 2011.

(3) “The technology represents a step change in power generation….the merits of high efficiency with coal-base fuel and inherent carbon capture – although a series of technical barriers remain….” Peter Childs, Gas Turbine World, May-June 2011 pp 24 -27

14

What Are Other Countries Doing?

Ch l U i it S d• Chalmers University, Sweden– Metal carriers, gaseous and solid fuels

• Southeast University, China– Nickel and iron carriers, direct coal combustion– Recent (2010) publications in pressurized CLC

• University of Cambridge, UKUniversity of Cambridge, UK– Copper and iron carriers with lignite coal (batch reactor)

• Instituto de Carboquímica (CSIC), SpainNat ral gas onl copper carriers– Natural gas only, copper carriers

• Vienna University of Technology, Austria– Natural gas only, two entrained reactors give better gas-solid

contact• Korea Institute of Energy Research (KIER)• Japan Coal Energy Center (JCOAL)

15

What’s Happening Domestically?

AlstomUtah Ohio

StateCMU

Pitt

WVU

KentuckyWesternKentucky

16

Kentucky

Basic Thermodynamics and yConversionIn CL combustion the overall reaction (1) of fuel with oxygenIn CL combustion, the overall reaction (1) of fuel with oxygenis split into two steps (2&3) , which add to the overall.

Consider an example of carbon and a metal/metal oxide (M/MO):

1) C + O2 CO2 H1 Overall fuel oxidation ‐ exothermic_______________________________________________________

2) C+ MO2 CO2 + M H2 Metal oxide reduction & fuel oxidation –can be endothermic OR exothermic

3) M + O MO H Metal oxidation ‐ exothermic3) M + O2MO2 H3 Metal oxidation  exothermic

H = H + H17

H1 = H2 + H3

Potential oxygen carriersMany oxygen carriers have been studied to date:Many oxygen carriers have been studied to date:Iron: Fe2O3 Hematite = Iron (III), Fe3O4 Magnetite = Iron (II,III), FeO= Iron(II), Wusite, FeCopper: CuO Copper oxide, Cu2O Cupric Oxide, Cu Nickel: NiO, Ni What large Manganese: MnO2, MnO, Mn2O3, Mn3O4 , MnCobalt: Co3O4, CoO, CoSulfates‐Sulfides: CaSO4‐CaS, MnSO4‐MnS, FeS‐FeSO4

And others: Sb Pb Cd

difference in system configuration must exist forAnd others:  Sb, Pb, Cd…

Thermodynamics for iron and copper:Methane overall½ CH4 + O2 ½ CO2 + H2O H1000K = ‐402kJ Exothermic overall reaction

must exist for copper versus iron carriers?

½ CH4 + O2 ½ CO2 + H2O H1000K   402kJ  Exothermic overall reactionCopper carrier8 CuO + CH4 4Cu2O +CO2 + 2H2O H1000C = ‐283kJ  Exothermic metal reduction4 CuO + CH4 4Cu +CO2 + 2H2O H1000C = ‐211kJ  Exothermic metal reduction2 Cu + O2 2CuO H1000K = ‐274kJ Exothermic metal oxidationI iIron carrier12Fe2O3 + CH4 8Fe3O4 + CO2 + 2H2OH1000C = +154kJ  Endothermic metal reduction4Fe2O3 + CH4 8FeO + CO2 + 2H2O H1000C = +303kJ  Endothermic metal reduction4/3Fe2O3 + CH4 8/3Fe + CO2 + 2H2OH1000C = +154kJ  Endothermic metal reduction4/3Fe + O2 2/3 Fe2O3 H1000C = ‐539kJ  Exothermic metal oxidation Hint: where does the heat

b ?

18

Fan, L. S., (2010). Chemical Looping Systems for Fossil Energy Conversions , John Wiley and Sons Publishers, see pp. 61 ff

/ 2 / 2 3 1000C go, above?

Thermodynamic limits on conversionHow much oxygen, CO, H2 will exist in the products of CL combustion?

CO E h d Oil R ifi ti * t bli h t ti l i tCO2 Enhanced Oil Recovery specification* establishes potential requirements:

CO2 H2O N2 O2 Ar CH4

vol% (Min) ppmwt vol% vol% vol% vol%Unit (Max unless Otherwise noted)Component

Design 95 300 1 0.01 1 1Range 90 - 99.8 20 - 650 0.01 - 2 0.001 - 1.3 0.01 - 1 0.01 - 2

H2 CO H2S SO2 NOx NH3

vol% ppmv vol% ppmv ppmv ppmvComponent

Unit (Max unless Otherwise noted)

Enhanced Oil Recovery

vol% ppmv vol% ppmv ppmv ppmvDesign 1 35 0.01 100 100 50Range 0.01 - 1 10 - 5000 0.002 - 1.3 10 - 50000 20 - 2500 0 - 50

COS C2H6 C3+ Part. HCl HFl% l%Unit (Ma nless Other ise noted)

Unit (Max unless Otherwise noted)

Enhanced Oil Recovery

Componentppmv vol% vol% ppmv ppmv ppmv

Design 5 1 <1 1 N.I.* N.I.*Range 0 - 5 0 - 1 0 - 1 0 - 1 N.I.* N.I.*

HCN Hg Glycol MEA Selexol -

Unit (Max unless Otherwise noted)

Enhanced Oil Recovery

Componentppmv ppmv ppbv ppmv ppmv -

Design trace N.I.* 46 N.I.* N.I.* -Range trace N.I.* 0 - 174 N.I.* N.I.* -

Unit (Max unless Otherwise noted)

Enhanced Oil Recovery

19

*QUALITY GUIDELINES FOR ENERGY SYSTEM STUDIES -CO2 Impurity Design Parameters, DOE/NETL-341/011212, Jan 2012. http://www.netl.doe.gov/energy-analyses/pubs/QGESSSec3.pdf

Understanding equilibrium limits on conversion

MeO2 O2 (g)Notice that at any temperatureif PO2 < PO2* defined by (i), the metal oxide (MO )is reduced to

Me

2 (g)CH4, CO, CO2, H2, H O

metal oxide (MO2)is reduced to the Metal (M).

Quiz for grad students:

The metal/oxide reaction(i)  M + O2MO2 ;  GT(i) = GT(i)˚ + RTln(1/PO2)

H2OQuiz for grad students:Your chemical looping combustor is making 30 ppm CO.

( ) 2 2 T(i) T(i) ( / O2)At equilibrium, GT(i) = 0, denote PO2

* ;  GT(i)˚/(2.3RT)= log(PO2*)

The gas‐phase reactions(ii)  2CH4 + O2 2CO + 4 H2 ; GT(ii)˚/(2.3RT)= 2log(PCH4

* / PCO*PH2

*2)+ log(PO2*)(iii) 2CO+O 2CO ; G ˚/(2 3RT)= 2log(P * / P *)+ log(P *)

Your professor wants you to add more metal oxide to improve CO burnout. Will it work?

(iii)  2CO+O2 2CO2 ; GT(iii) /(2.3RT)= 2log(PCO / PCO2 )+ log(PO2*)(iv)  2H2+O2 2H2O ; GT(iv)˚/(2.3RT)= 2log(PH2

* / PH2O*)+ log(PO2*)

If you have the values for GT˚’s you can solve immediately for PO2*,  (PH2

* / PH2O*) and (PCO

* / PCO2*). You can get absolute concentrations of CO and H2

A) Yes because….B) No because….C) Maybe because….D) I just want to

d t

20

by noting the fuel is mostly converted to CO2 and H2O. graduate.

Fe2O3 reduction to Fe3O4 with H2/CO

The metal/oxide reaction

(i)  M + O2MO2( ) 2 2

The gas‐phase reactions

(iii) 2CO+O 2CO(iii)  2CO+O2 2CO2

(iv)  2H2+O2 2H2O

Figure shows the reduction of Fe2O3Fe3O4 with H2 or CO. Even at equilibrium, there are ppm levels of residual H2 & CO making a slightly reducing environment. Residual CO increases with temperature because the reduction reaction is slightly exothermic (H2 reduction here is endothermic). Results are based on simulations using HSC Chemistry 7.1. Courtesy Mike Gallagher, NETL.

21

Solid Carbon Formation• What happens if any solid carbon is left on the oxygen carrier pp y yg

when it leaves the fuel reactor? (Red arrow, below)• Carbon formation via equilibrium (chart, right) and also

hydrocarbon cracking.y g• Notice that solid carbon on a metal oxide may not be a problem!

Boudard Reaction Equilibrium

1.E-01

1.E+00

CO

C (s) +CO2(g) --> CO(g), 1atm, only CO/CO2 gases*

CarbonCarbonFormsFormsCO + H O

N2 + O2

(vitiated air)

1.E-03

1.E-02

olum

e Fr

actio

n C FormsForms

CarbonCarbonGasified Gasified to COto CO

CO2 + H2O

Ash

Seal

1.E-05

1.E-04

0 200 400 600 800 1000 1200

Vo

Temperature (C)

to COto CORecycle

CO2 + H2OFuelSeal

22*Gaskell, D. R. (2008) Introduction to the Thermodynamics of Materials, 5th ed, Taylor and Francis, pp. 365-366

Temperature (C)Air

OXYGEN CARRIER CAPACITY ANDCIRCULATION RATES

Fully reduced Partially oxidized Fully oxidizedFully reducedactive species(e.g., Cu, Fe, etc.)

Partially oxidizedactive species

Fully oxidizedactive species(e.g., CuO, FeO, etc.)Define

conversionconversionX

for a Inertsupport,mass: minrt

“supported” metal oxide

carrieractive mass: mred

X = 0

active mass: mox

X=1

active mass: m

X =m-mred

m m

carrier

23

X 1X mox-mred

NomenclatureXactiveI

dize

d st

ate)

0.80

1.00

A C

X X2X1active

mass: mmred <m< mox

Inertsupport,mass: minrt

carr

ier (

1 kg

oxi

d

0.00

0.20

0.40

0.60

BConversion

Mas

s of c

0.98

1.00

0.000 0.2 0.4 0.6 0.8 1

A= Active mass, oxidizedB I

0.90

0.92

0.94

0.96 CB = Inert massC = Working oxygen capacity

Ro = C/A

Oxygen transport capability 0.90

0 0.2 0.4 0.6 0.8 1

= A/(A+B) Ro = C/(A+B)

24

Values for Oxygen Transport Capability (Ro) for Some Metal/Oxide PairsSome Metal/Oxide Pairs

Inexpensive

Fe2O3 / Fe3O4 0.034 Mn2O3 / MnO 0.100Mn2O3 / Mn3O4 0.034 Cu2O/ Cu 0.110CuAl2O4 / CuAlO2 0.044 CuO / Cu 0.200

Good capacityFe2O3Al2O3 / FeAl2O4 0.045 CoO / Co 0.210Co3O4 /CoO 0.067 NiO / Ni 0.210Mn3O4 / MnO 0.070 Co3O4 /Co 0.270CuAl2O4 /CuAl2O3 0.089 ZnSO4 / ZnS 0.396NiAl2O4 / Ni Al2O3 0.091 CuS04 / CuS 0.401CuO / Cu2O 0.100 MnSO4 / MnS 0.424Fe2O3 / FeO 0.100 FeSO4 / FeS 0.425

Table 1.  Values of Ro for some potential oxygen carrier reactions, arranged small to large.

Very inexpensive.Throw-away option

CaSO4 / CaS 0.470

25

Establishing Carrier Requirements from FCC Experience

Petrochemical Fluid Catalytic Cracking (FCC)Proven Process Technology

FlueCycloneVessel

Gas

CatalystRegenerator

StrippingStream

Stripper

Stripper

Air

StripperStandpipe

RegeneratorStandpipe

RiserReactor

Air Heater

Dispersion Steam

Lower Feed Injection

26

Properties of the Oxygen Carrier

• Assuming a solids circulation rate ~ operating fluid catalytic crackers (41,000 kg/min)C l l t th th l t t ibl f h i l• Calculate the thermal output possible for a chemical looping system for different carriers/conversions

1200

1400

1600

1800

2000

ut [M

W]

[Pure Cu: CuO→Cu]

atin

g R

ange

?

4

5

6

[Ilmenite: Fe2O3→FeO] [Pure Cu: CuO→Cu]

[40% Cu, 60%Al2O3: CuO→Cu]

400

600

800

1000

1200

Ther

mal

Out

pu[Pure Fe: Fe2O3→Fe3O4]

[Ilmenite: Fe2O3→FeO]

[Cu, 60%Al: CuO→Cu]

[Pure Fe: Fe2O3→FeO]

ccep

tabl

eO

pera

0 500 1000 1500 2000 2500

1

2

3

[Pure Fe: Fe2O3→Fe3O4]

[Pure Fe: Fe2O3→FeO]

[Ilmenite: Fe2O3→Fe3O4]

0

200

0.5 0.7 0.9Conversion

[Pure Fe: Fe2O3→Fe3O4][Ilmenite: Fe2O3→Fe3O4]

Ac0 500 1000 1500 2000 2500

Thermal Output [MW]

27

KINETIC RATES AND REACTOR SIZE

28

KINETIC RATES AND REACTOR SIZEA “bubbling” fluid bed (BFB) is one possible reactor configuration (left)A bubbling fluid bed (BFB) is one possible reactor configuration (left).BFB is approximately like a stirred reactor (right).The usual combustor design concepts apply:

1) heat release rate balances the incoming rate of cold reactants or it will blow out2) f i th h t th t l i i l ti l t th ti t2) for a given throughput, the reactor volume is inversely proportional to the reaction rate.

Carrier State X1

Reactor Temperature

T

Fluid Bed

CarrierInputsm X

Outputs

Air

Carrier State X2

moc,iXimair,i

Ti

Reactor Volume

VR

moc,oXmair,oT

29

Experimental measurement of kineticsThermo gravimetric Analysis (TGA)g y ( )

thermocouple

For gaseous reactions, sample weight describes the conversion:

Cycling the fuel and oxidizer over the sample pan will give many “cycles” to analyze.

Solid fuels (coal and biomass): must re load the pan every cycle

30

Solid fuels (coal and biomass): must re-load the pan every cycle.

Example of kinetics measurement (CH4)TGA Data for Cu-based carrier4 4 2CuO CH Cu CO H O

0.8

1

800

1000

42

44

TGA Data for Cu-based carrier 4 2 24 4 2CuO CH Cu CO H O

0 4

0.6

nver

sion

(X)

750

T (oC)

400

600

800

36

38

40

pera

ture

(o C)

Mas

s (m

g)

100% CH4

0.2

0.4

Con 800

850900

0

200

400

30

32

34 Tem

pM

1 rr

ox r

m mXm m

dp=150-250 m

100% CH4, 800 oC

Typical mass and temperature measurement for CuO/bentoniteparticle and 100% CH for reduction and air for oxidation

Effect of reaction temperature on CuO/bentoniteti l d CH ti

00 0.4 0.8 1.2 1.6 2

Time (min)

0300 500 1000 1500 2000

Time (min)

particle and 100% CH4 for reduction and air for oxidation reactions

particle and CH4 reaction

4

11(1 )[ ln(1 )]m n

CHdX ky n X Xdt

Results fit to Jonson-Mehl-Avarmi (JMA) rate equation

31

Monazam et al. (2012) “Kinetics of the Reduction of CuO/Bentonite by Methane (CH4) During Chemical Looping Combustion”, to appear Energy and Fuels.

dt

A visual representation of reaction rates• An informative/interesting way to see the metal-metal oxide cycle.g y y• Combustion Quiz

– What type of flame does a propane torch use (e.g., diffusion, premixed, partially premixed?)

– What is the partial pressure of oxygen inside the flame?

M i f d ti dMovie of copper reduction and oxidation

32

Kinetics in a stirred reactor bed (1/2)• With kinetic rates write• With kinetic rates, write

energy and mass balances with an “efficiency” of conversion (defined

1800

2000Air Reactor (Cu2O‐‐>CuO)

10 sec

800C Input Tempconversion (defined below).

• Does the bed have “light-off” behavior? 1000

1200

1400

1600

Temperature (C)

800C ‐ Input Temp 

behavior?

400

600

800

1000

Reactor Internal T

Tout at steady-state

0

200

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Efficiency (N‐I)

state

Green line depicts efficiency as a function of output temp (from mass balance), dashed line shows same using energy balance equations. Point of intersection is the desired steady-state solution.

33

Kinetics in a stirred reactor bed (2/2)• With kinetic rates write• With kinetic rates, write

energy and mass balances with an “efficiency” of conversion (defined

1800

2000Air Reactor (Cu2O‐‐>CuO)

10 sec

800C Input Tempconversion (defined below).

• Does the bed have “light-off” behavior? 1000

1200

1400

1600

Temperature (C)

800C ‐ Input Temp 

Different inlet temperature, mass flow, etc.

behavior?

400

600

800

1000

Reactor Internal T

Tout at steady-state

0

200

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Efficiency (N‐I)

state

Green line depicts efficiency as a function of output temp (from mass balance), dashed line shows same using energy balance equations. Point of intersection is the desired steady-state solution.

34

Work in progress at NETL – example(based on kinetics currently studied; subject to revision, etc.)

• Iron-based– Air reactor:

• Notice that the rates are significantly Air reactor:

- 2.5 MW/m3 exothermic– Methane Fuel Reactor:

+ 0 4 MW/m3 endothermic

g ydifferent.

The system and+ 0.4 MW/m3 endothermic

• Copper- based– Air reactor:

• The system and reactor design is dramaticallyAir reactor:

- 13MW/m3 exothermic– Methane fuel reactor:

5 4 MW/ 3 th i

dramatically different.

1 m- 5.4 MW/m3 exothermic

6.3 m(~21ft)

1 m (~3ft)

Approx 40 m3

35

(~21ft)6.3 m(~21ft)Approx 40 m

Reactor and System Design

36

Reactor and System Design• Significant/similar two phase• Significant/similar two-phase

experience already exists for – Fluid Catalytic Cracking

Technology

Proven Process TechnologyFluidized Catalytic Cracker (FCC)

Technology– Circulating Fluid Bed

CombustorsR t D i D d

FlueGas

St i i

CycloneVessel

Stripper• Reactor Design Depends on

Fluidization Engineering– Chemical engineering

t d d f

CatalystRegenerator

StrippingStream

StripperStandpipe

RiserR t standard fare.

– Not usually covered in combustion engineering t d

Air

Air HeaterLower Feed Injection

RegeneratorStandpipe

Reactor

today.Dispersion Steam

37

JEA 300 MW Circulating Fluid Bed (CFB) Combustor, Jacksonville, Florida, ,

Power magazine’s 2002Power magazine s 2002 Power Plant Award. Nominated for Power Engineering magazine’s 2003 Power Plant of the Year Award

Significant commercial experience exists for large CFB’s.

“…..the mass flow rate of recycled solids is many times the mass flow rate of incoming air, fuel, and limestone….the bed solid temperature remains relatively

38

incoming air, fuel, and limestone….the bed solid temperature remains relatively uniform” Steam, Edition 41, pp. 17-9, The Babcock and Wilcox Company

Reactor Schemes from Various Research GroupsBFB = Bubbling fluid bed, CFB = Circulating fluid bed

S f h i l l i it ith t t hi h th 10 kW Th ti ti d t th i d ith ti l i l ti t hi h t t

LocationUnit size

kWth Configuration Fuel Oxygen-carrierOperation time

hoursa

Gaseous fuelsChalmers University of Technology, Chalmers, Sweden 10 Interconnected CFB-BFB n.g. NiO, Fe2O3 1350

Summary of chemical-looping units with power output higher than 10 kWth. aThe operation time corresponds to the period with particle circulation at high temperature.

From :Adanez et al. (2012). Progress in Chalmers, Sweden 10 Interconnected CFB BFB n.g. NiO, Fe2O3 1350

Institute of Carboquimica, ICB-CSIC, Spain 10 Interconnected BFB-BFB CH4 CuO 200

IFP-Total, France 10Interconnected BFB-BFB-BFB CH4 NiO n.a.

Xi’an Jiaotong University China 10Interconnected Pressurised CFB-BFB Coke oven gas Fe2O3/CuO 15

( ) gChemical-Looping Combustion and Reforming Technologies, Prog. In Enegy and Combustion Science Xi an Jiaotong University, China 10 CFB BFB Coke oven gas Fe2O3/CuO 15

ALSTOM Power Boilers, France 15 Interconnected CFB-BFB n.g. NiO 100Korean Institute of Energy Research, KIER, Korea 50

Interconnected CFB-BFB (KIER-1) BFB-BFB (KIER-2) CH4 CH4, CO, H2

NiO, CoO NiO, CoO 28 300

Technical University of Viena, Tuwien, Austria

120 (CLC) 140 (CLR) DCFB CH4, CO, H2 CH4 NiO, ilmenite NiO > 90 20

Solid fuels

38, pp. 215-282

Solid fuelsChalmers University of Technology, Chalmers, Sweden 10 Interconnected CFB-BFB Coal, petcoke ilmenite 90Southeast University, China 10 CFB-spouted bed Coal, biomass NiO, Fe2O3 130Ohio State University (OSU), Ohio, USA 25

Interconnected Moving bed-Entrained bed Coal Fe2O3 n.a.

ALSTOM Windsor Connecticut USA 65 Interconnected CFB CFB Coal CaSO n a

l h d i ( ) i f h i l i l f l d l li i

ALSTOM Windsor, Connecticut, USA 65 Interconnected CFB-CFB Coal CaSO4 n.a.Darmstadt University of Technology, TUD, Germany 1 MWth Interconnected CFB-CFB Coal ilmenite Operational in 2011ALSTOM Windsor, Connecticut, USA 3 MWth Interconnected CFB-CFB Coal CaSO4 Operational in 2011

39

See also Moghtaderi, B. (2011). Review of Recent Chemical Looping Process Development for Novel Energy and Fuel Applications, Energy and Fuels, 26, pp. 15-40. Describes many other unique process options .

Modeling of Fluidized Beds

(Courtesy: M. Rhodes, Monash U.)(Courtesy: F. Shaffer, NETL) Movie

Continuum ModelsDiscrete Models

DEMDEMLBMLBMDNSDNS MPMP--PICPIC MultiMulti--FluidsFluids FilteredFiltered--EqsEqs ROMROM

fi tl d

40

www.mfix.netl.doe.gov

Comparison of CFD and Cold Flow Rig

O

SIMULATION EXPERIMENT

Oxygen carrier Lighter ash

carried out with fluidizing steamor CO2

M i

Airreactor

Movie

Solid fuel i t thi b d

Oxygen carrier

41

into this bed

Research at Princeton University: Research at Princeton University: Prof.Prof. SankaranSankaran SundaresanSundaresan, ,

Filtered Two-Fluid Modelyy ,,

William Holloway, William Holloway, YesimYesim IgciIgci, Art Andrews, Peter , Art Andrews, Peter LoezosLoezos, , KapilKapil AgrawalAgrawal

The Problem:The Problem: Gas-particle flows in large vessels• Two fluid model computations

128 x 128

• Two-fluid model computations• Practical limitations on grid resolution• Need filtered two-fluid models and closures

The Goal:The Goal:To develop filtered two-fluid model by averaging the small scale structures that will not be resolved in the coarse

256 x 256

spatial grid simulations.

512 x 512

42

MFIX Simulations of 75 μm particles in air

Solid fuel combustion

43

TGA P fil f C l +C O i N

Can We Use Coal Directly?TGA P fil f C l i N TGA Profile of Coal +CuO in N2

35

401000

N2 O2

TGA Profile of Coal in N2

200

210 1000Nitrogen Oxygen

200

210 1000Nitrogen Oxygen

20

25

30

ht (m

g) 600

800 Reaction tempe

44.88%190

200

ht (m

g) 600

800

Temperat

190

200

ht (m

g) 600

800

Temperat

5

10

15

wei

gh

0

200

400

erature (oC)

55.12%

Volatiles &mositure out

combustion

combustion

170

180

Wei

gh

200

400

ture ( oC)

170

180

Wei

gh

200

400

ture ( oC)

0 50 100 150 200 250

0

Reaction time (min)

0

0 20 40 60 80 100 120 140 160 180160

Reaction Temperature (oC)

0 20 40 60 80 100 120 140 160 180160

Reaction Temperature (oC)Reaction time (min)

Rates wereRates were higher than expected.

44

Why?

Reaction Pathways for Solid Fuel CLC

• Coal CLC with metal oxides via gaseous intermediates: In N2:

Coal Coal pyrolysisCO/H2 + CuO Cu +CO2 /H2O

CO2 + C 2CO 2

In CO2:C+CO2 2CO

CO+CuO Cu+COCO+CuO Cu+CO2

• CLOU mechanism (Chemical Looping Oxygen Uncoupled):CuO Cu/Cu2O +O2 Discussed Coal + O2 CO2

• Solid-solid interaction: MeO+C MeO +CO2

next

45

2

Possible Reasons for Rapid, Low-Temperature reaction of solid carbon with CuO

2CuO = Cu2O + 1/2O2

At 500 oC, PO2 is 1.1*10-9 10-2 = PO2 10-9 = PO2>At 500oC

At 500 C, PO2 is 1.1 10

Will removal of oxygen (1.1*10-9) continuously by carbon, facilitate the C O d iti ?

No Reaction

Reactionnot possible at low O2

CuO decomposition?

• Reacted C with various oxygen partial pressures

CuOCuO

Reaction

Carbon CarbonSignificant pressures

– With air: modest reaction at 500-600oC.– No reaction at 500-600 oC with oxygen at

low O2 partial pressure (<2%, vitiated air)

Reactionat 500oC

vitiated air

– Confirms that PO2 is 1.1*10-9 not sufficient to react with C at 500 oC to facilitate the forward reaction at sufficient rates

46

Combustion Rates of Coal (100 micron) with Various Particle Sizes of CuO in TGA

0.10~5 micron

1000

0.08 Reactio

5 micron713 oC

63-177 micron780 oC

-1)

800

0.04

0.06

on temperatur

354-595 micron874 oC

ctio

n ra

te (m

in-

400

600

0.02

re ( oC)R

eac

200

0 20 40 60 80 1000.00

Reaction time (min)

0

47

Higher combustion temperature with increasing particle size

Effect of Dilution by Quartz Powder on the TGA Combustion Performance of Carbon and CuOCombustion Performance of Carbon and CuO

• Mixed CuO, Quartz and C powders

• CuO/C ratio was kept constant

• Reaction T increased with i d dil tiincreased dilution

These data and others (flow tests + DFT(flow tests + DFT calculations)* suggest a solid-phase reaction between carbon and the oxygen carrier (Fe too)oxygen carrier (Fe, too).

Reduces coking automatically!

48

* Siriwardane, R. Tian, H., .Miller, D., Richards, G., Simonyi, T., Poston, J. (2010). Evaluation of reaction mechanism of coal-metal oxide interactions in chemical-looping combustion, Combustion and Flame, Combustion and Flame, Volume 157, Issue 11, November 2010, Pages 2198-2208

Comparing CO2 Release from Carbon-Metal Oxidewith O2 Release from Neat Metal Oxide

Courtesy Michael R. Zachariah, University of Maryland

200Comparison of CO2 and O2 Release Temperature Jump Mass Spectroscopy

Copper Oxide(similar for iron oxide)

150

200

CO2 C-CuO run-1O2 from CuO run 3 CO2 from C-CuO run-2O2 from CuO run 4

Resistance heating of sample-coated wire allows study of reaction chemistry with C-CuO mix orevolution of oxygen from neat metal oxide via equilibrium

100

nsity

(a.u

.) Movie

50

Inte

n

0

0 1 2 3 4 5 6

Time (ms)CO2 from C-CuO O2 from CuO

Reaction is occurring before oxide’sRelease of O2 to the gas phase

49

( )CO2 from C CuO 2

ICMI Research Areas

Focus is on “industrial” applications: NG or coal boilers, process heat, chemical production, others. Technical results expected to benefit coal power as well.

CO2 & H2

Carbon Capture

CH3OH

Carbon UtilizationCarbon StorageCarbon CaptureChemical Looping Combustion Photocatalytic Conversion Depleted Shale Fields

CCUS for CCUS for

Industrial assessment

Industrial Applications

Industrial Applications

50

and systems analysis

Potential Chemical Looping Application

• Steam Production– In any industrial or

commercial facility where yboilers are in use

– Oil Sands production & processing, especially Steam Assisted Gravity D i (SAGD) Steam OilDrainage (SAGD) very attractive

– Oil & Gas production, especially where CO2could be used for EOR

Injection Production

could be used for EOR• Electric Power Generation

– Need to fully characterize size & complexity of the systems

Steam Chamber

Steam Injection

Oil Production Reservoirsystems – Analysis coordinated with

NETL studies of power systems

O oduct o Reservoir

SAGD Process

51

Developing and Validating the CL TechnologyIndustrial applications Power applicationsIndustrial applications

(includes NG, smaller scale)Power applications

(coal, 100+MW scale)• Attributes:

– Fuel (NG, solid fuels)– Size– Size– Cost– Performance

• System issues & configuration– Attrition

M t i l l & h dliIterate withmoreinformation

– Material supply & handling– Heat exchanger/integration– Sensors and control– Emissions– Carrier cost/supply & re-use

ICMI research task provide the data and analysis.

• Components– Hydrodynamics– Heat transfer– Size/cost

• Basic data

These data will enable CCSI* scale-up simulation.

Basic data– Carrier capacity– Carrier reaction rate w/oxygen– Carrier reaction rate w/fuel– Carrier degradation

52

* Carbon Capture Simulation Initiative - www.acceleratecarboncapture.org

C i f CLR t d h b id tifi d d f ll

Oxygen Carrier Development • Carriers for CLR study have been identified and full

report on screening study is available– Hematite – natural ore– Cu-Fe/Al2O3 - synthetic materialy

• Mixed-metal oxides developed at NETL• Vendors have been identified to provide materials• Quality testing underway on vendor-supplied hematite

Example of TGA cycle studies showscycle studies shows good stability and oxygen capacity

Reduction rate (min-1)

Oxidation rate (min-1)

Oxygen transfercapacity (%)

Il it 0 18 0 49 4 6

53

Ilmenite 0.18 0.49 4.6Hematite 0.33 0.52 10

Non-Reacting Cold Flow UnitU d t i l t d h t i th• Used to simulate and characterize the behavior of solids transfer and the control of oxygen carrier particles.

Measured characteristics: gas particle• Measured characteristics: gas-particle velocity fields, 3-D solid-void fraction distributions, bubble size, bubble frequency.

• Geometry and flow match the hot unit except for the temperature.

• Acrylic construction allows for visual• Acrylic construction allows for visual identification of the flow structures and use of advanced instruments such as high speed particle imaging velocimetry.

• Provides hydrodynamic validation data for various models and provides a similar system to explore control strategies

54

strategies.

Validating the Predictions: Laboratory Scale Chemical Looping Reactor (CLR)

Current Status: Being Installed at NETLCycloneC-1200

Test Section UpperC-1250

Loop Seal R-1300

Upper RiserR-1150

Lower RiserR-1100

Fuel ReactorR-1400

CLR Vessels Delivered to NETL

Project

AirL-Valve

R 1400 Project Structure

Air Reactor Bubble CAir

ReactorR-1000

Housing R-1450

Caps

55

Air Pre-heater and Tee H-1800 & H-1850

Air Pre-heater and Tee H-1800 & H-1850

Modeling the Chemical Looping Process

CycloneC-1200

Test SectionC-1250

Upper RiserR-1150

Separation Cyclone Crossover

Loop Seal R-1300

R-1150

Lower

Fluent2D Simulations 3D Simulation

LoopSeal

RiserR-1100

Fuel ReactorR-1400

Barracuda (3D)Cold Flow

Simulations Fuel

Riser

Air ReactorR-1000

L-Valve Housing R-1450

Hot SimulationsReactor

Air Pre-heater and Tee H-1800 & H-1850

Air Pre-heater and Tee H-1800 & H-1850

Air ReactorL-Valve

Solids Flow

56

CLR whole system – 3D, front view

Hot Loop Results - Solids

Movie

57

Chemical Looping – Discussion/ Thinking Question

• Relative to theRelative to the earlier discussion of the figure at the left:

Define: = (kg CO2 produced) / (kg fuel burned )CO2 = (separation work, Joules ) / (kg CO2) CO2

– Does chemical looping “fit” this description?g

– What are the potential benefits and drawbacks of chemical

GeneratorCarbon

Q = mfHFuel Heat

Input

gGeneratorEfficiency

WoGross

Generator

W1Net

Outputof chemical looping w/r to efficiency?

• What applications

Carbon SeparationUnit

Work

ppof chemical looping are most attractive?

58

Approx Ranges: (30 – 60%) (6-10%)

Chemical Looping Summary• Not completely new but new interest because of CO2 capture• Not completely new, but new interest because of CO2 capture.• Various metal/metal oxide pairs are candidate oxygen carriers.• For a given heat output, reactor circulation rates depend on the

oxygen capacity.• Practical experience from CFB and FCC applications suggest

the range of application.• Kinetic work and reactor designs are in progress.• Models and validation tests are also in progress.

59