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Captura, transporte y

almacenamiento de CO2Captura de CO2 por

Prof. Vicente J. Corts

post combusti nMaster en Ingeniera Ambiental

Curso 2012-2013


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Alternativas tecnolgicas para la captura de CO 2 Fundamentos

Absorcin

Adsorcin

Indice

Membranas Estado de desarrollo

Principales retos Proyectos europeos de demostracin


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Alternativas tecnolgicas para lacaptura de CO2

Fundamentos Absorcin

Presentation Outline

sorc n Membranas

Estado de desarrollo

Principales retos

Proyectos europeos de demostracin


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CO2 3-15%

Technology options

CO2 40%

CO2>95%

Adapted from EPRI 2007


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Post-combustion capture: separation CO 2-N2Pre-combustion capture: separation CO 2-H2Oxyfuel combustion (Denitrogenation): pre-separation O 2-N2

- -

Capture Routes: Classification

.(flue gas)

.(shifted syngas)

.(exhaust)

p (bar) ~1 bar 10-80 ~1 bar

[CO 2] (%) 3-15% 20-40% 75-95%

Partial pressure of CO 2 in the flue gases fromexisting power plants is very low


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The challenge: huge scale of operation

Coal feed : 164 x 103 kg/h

Stack gas flow rate : 2.200 x103 kg/h ~ 54 x103 t/dCO2 flow rate : 370.000 kg/h ~ 8,9 x103 t/d

*

500 MW USC Coal Fired Power Station

. ,

*Cryogenic conditions typically 1,7 MPa, -30 oC

Figures for a

500 MW SC Coal Fired Power Station: 12% higher


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sorc n Membranas


Principales retos



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Postcombustion: basic approach

Compatible with low partial pressure of CO2 in flue gases CO2Deh dration

CO2Deh dration

CO2Deh dration

CO2

N2O2

Air

Coal

CO2 SeparationPower & Heat

CO2

10-14%0.9 g CO2/kWh

NGas CO2 4-5%0.35g CO2/kWh

Suitable for retrofittings and capture-ready conceptsLeading candidate for gas-fired power plants, if required

Learning by doing through easily scalable pilots processing slip streams

Solvent technologies proven on a smaller scale at CPI*

Learning by searching will lead to better solvents and process integration

Applicable to other carbon-intensive industries: oil refining, cement

andCompressionandCompressionandCompression

*chemical process industries


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Technology options for postcombustionCO2 capture

CO2 Separation and Capture

GasSeparation

AdsorberBedsChemical

Microbial/Algal

SystemsMembranesCryogenicsAdsorptionAbsorption

Activated carbonOther2PolyphenylenoxideAmines

1Alumina PolyimidesAmmonia Zeolite, MOFs

Gas

Absorption

Regeneration

MethodsPhysical

Ceramic BasedSystems

PolypropyleneSelexol Pressure SwingRectisol Temperature SwingOther Washing

1. Primary, secondary, tertiary, sterically hindered2. Alkaline compounds, Salts of aminoacids


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sorc n Membranas


Principales retos



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CO CAPTURE SOLVENT

VENT GAS TO STACK CO2 TO COMPRESSOR

SOLVENTMAKE-UP

LEAN SOLVENT

Absorption schematics

ABSORBER STRIPPING

Uptake of CO2 into de bulk phase of a liquidsolution w/o chemical reaction

ENTALPHY

FLUE GAS (CO2)

RICH SOLVENT(+ CO2)

SPENT SOLVENT

Flue gas contacted with a reagent-containing solventCO2 transfers from the gas phaseinto the liquid phaseCO2 selectively reacts with the

reagent

The CO2-loaded rich solution ispumped to a regenerator vessel to beheatedGaseous CO 2 is stripped (liberated)Lean solution is circulated back to the

absorber


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Chemical vs. Physical Absorption

IEA GHG


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Simplified flowsheet

Source: SINTEF, 2010


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Simplified flowsheet


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Counter current flow through apacked column is most common

Plate towers are also used,mainly in the stripping step*

Types of columns

*Image source: Mass Transfer Operations, R.E. Treybal, (1980) McGraw-Hill


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1. Very high gas flow rates: large columns

2. Large solvent flow rates: important auxiliaries consumption

3. Steam extraction for solvent regeneration: parasitic load of 20-30% *

Absorption technology issues

. 2 3 ppmv required

5. Solvent and reaction products may exit the absorber: potentialimpact on HS&E of nitramines and nitrosamines

* CO2 compression included GCCSI


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Near-term absorption technologies

1. Currently emphasis on absorption on near-term technologies

2. Industrys CO2 capture chemistry knowledge and overall process

experience are both heavily slated towards absorption3. All near-term technologies are solvent based involving either

proprietary amines or ammonia

4. Distinction between these technologies are

Specific capture chemistryProcess configuration and integration into the power plant

5. Near-term technologies have been tested at scales on slipstreams no larger than 5-25 MWe from coal-fired power plants

GCCSI


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Key characteristics

Absorption solvents

To reduce height requirements for theabsorber and/or

Reduce solvent circulation flow rates

High reactivity withrespect to CO 2

Based on a low heat of reaction withLow re eneration

Davidson

CO2

cost

Which directly influences solventcirculation flow rate requirements

High absorptioncapacity


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Absorption solvents

Reduced solvent waste due to thermaldegradation

High thermalstability

Reduced solvent waste due to chemicalReduced solvent

Key characteristics

Davidson

degradation

degradation

Easy and cheap to produceLow solvent costs

Low environmental impact


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Primary and Secondary Amines

2(R-NH2) + CO2 R-NH-COO- + R-NH3+

Two solvent molecules required for each CO 2 molecule sorbedFast rate low ca acit

Amine-based absorption processs

Carbamate

Low T

Example: Mono-ethanol amine, MEA HOCH2CH2NH2


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R3-N + CO2 +H2O R3-NH + HCO3-

One solvent molecule required for each CO 2 molecule sorbedSlow rate romoters re uired hi h ca acit

Bicarbonate

Tertiary and Hindered Amines

Amine-based absorption processs

Example: MDEA ( HOCH2CH2)2NCH2


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Block flow diagram of theEconamine FG+ process using MEA


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Ammonia-based absorption processChilled ammonia

Ammonium carbonate solution + CO2 Ammonium bicarbonate

cooledflue gas

CO2 (g) CO2 (g)

T raise atrelatively high P

A slurry consisting of a liquid in equilibrium with solid ammoniumbicarbonate (NH4HCO3) is produced in an absorber

The slurry releases CO 2 at a relatively high pressure after beingheated in a desorber

(NH4)2CO3 (aq) + CO2(aq) +H2O(l) 2(NH4)HCO3 (aq)(NH4)2CO3 (aq) (NH4)2CO3 (s)


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Ammonia-based absorption process


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High CO2 purity

Tolerant to oxygen and flue gas impurities

Solvents for Post Combustion

Chilled ammonia advantages

No emission of trace contaminants

Low cost, globally available reagent


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Simplified flow sheet ACAP process


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Comparison of Solvent Properties

Cost(US$/lb)

Volatility(atm x 103 at 40C)

Degradation Corrosion

Solvents for Post Combustion

.

MDEA 300 0.003 Moderate Moderate

Ammonia 5 200 None High

PotassiumCarbonate 40 0 None High

Rochelle, 2007


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FUEL100% CO2COMPRESSION

NET OUTPUT34,2%

Absorption technology: energy penalty

Sankey diagram : Postcombustion USC pulverized coal PP

COOLING53,0%

AUXILIARIES3,4%

CAPTURE PROCESS(Enthalpy&Electricity)5,7%

,

0 10 20 30 40 50

REFERENCEPLANTUSC PC

WITH CCS

EFFICIENCY, %

Based on MIT data


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Subcritical power plant50

45

40

35 i e n c y ,

%

50

45

40

35 n c y ,

%

USC power plant

43.3

34.134.3Amine unit(entalphy)

-0.7

-5.0

-3.5Amine unit(entalphy)

CO2Compressor

Amine unit(power)

Absorption technology: energy penalty

Subcritical

30

25

20

E f f i

Ultrasupercritical

30

25

20

E f f i c

i

USCno

Capture

USCwith

CaptureNoCapture

25.1

WithCapture

-5.0 CO2Compressor

-3.5

-0.7

Amine unit(power)


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CCQ: relative increase or decrease in the emission factor of asubstance due to a certain capture technology

Carbon capture quotients

CCQx,y,z < 1 indicates a decrease in emission factor as aconsequence of CCS

yx,

zy,x,zy,x,

noCCSEF

CCSEFCCQ === =

CCQx,y,z Carbon capture quotient for air pollution substance 'x', given energy conversion technology 'y'and CO2 capture technology 'z

EF CCSx,y,z Emission factor reported/estimated for air pollution substance 'x', energy conversion technology'y' and CO2 capture technology 'z

EF noCCSx,y Emission factor for air pollution substance 'x' and energy conversion technology 'y'reported/estimated for the reference plant without CO 2 capture

CCQx

0150

EEA, 2011

Ai ll i i


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Capture quotients for primary energy, CO 2, SO2, NOX, PM and NH3Postcombustion results in no NO X reduction and much higher

emission of other nitrogen compounds

Air pollution impacts

CaptureTechnology

Conversiontechnology

Primary energynew capture CCQCO2 CCQSO2 CCQNOX CCQPM CCQNH3

Post--combustion

NGCC 1.11 0.13 - 1.00 - 1.25-30.30

PC 1.22 0.10 0.15 0.94 0.71 17.50-45.25

Pre-combustion IGCC 1.13 0.11 0.45 0.85 1.00 -

Oxyfuelcombustion

NGCC 1.20 0.02 - 0 - -

PC 1.22 0.05 0.06 0.42 0.06 -

EEA, 2011

P i O li


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sorc n

Membranas


Principales retos


Ad ti h ti


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VENT GAS TO STACK CO2 TO COMPRESSOR

Adsorption schematics

ADSORPTION DESORPTION

Uptake of CO2 onto the surface of a solid sorbent viaphysisorption or chemisorption in packed or fluidized beds

SORBENTREGENERATION

FLUE GAS (CO2)

SORBENTMAKE-UP

RICH SORBENT(+ CO2)

LEAN SORBENT

SPENT SORBENT

CO2 CAPTURESORBENT

REGENERATION P

ENTALPHY

Ph i ti Ch i ti


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Physisorption vs. Chemisorption

Van der Waals: Weak forces

Covalent bonding: Strong forces, sites necessary

Adsorption beds


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Adsorption beds

Flue gas flows through voidspaces between adsorbentparticles

Regeneration by heating the

Packed beds

2 - a en a sor en

Flue gas diverted to a secondpacked bed

At least two beds are needed

GCCSI

Adsorption beds


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Adsorption bedsFluidized beds

Flue gas flows upwardthrough a column

Adsorbent particles aresuspended in the gas flow

GCCSI

Sorbent circulated betweenabsorber and regenerator

At least two vessels areneeded

Adsorbents characteristics


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Solid (usually granular, beads, pellets) materialSelective for one or more components in the gas phase

High accesible porosity

Large internal surface area (up to 1000-3000 m2/g)

Adsorbents characteristics

Pore size distributions of common clases of adsorbents

Micropores dp< 20 nm

Mesopores 20 nm dp < 500 nm

Macropores dp 500 nm

CO 2collisiondiameter3.996 nm

Adsorbent attributes


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Capacity: the amount of adsorbate taken up by the adsorbent perunit mass ( or volume) of the adsorbentSelectivity: is the ratio of the capacity of one component to that of

another at a given fluid concentrationRegenerability: Necessary to have the the adsorbent operating in sequential

Adsorbent attributes

cycles Related to the strenght of adsorption forces Affects the fraction of the original capacity that is retained :

working capacity

Mass transfer kinetics: fast diffusion of adsorbate requiredMechanically strong to withstand bulk handling and attrition

Working capacity of adsorbents


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Working capacity 1.3%wt 0.3 mole/kg adsorbent

500 MWe Supercritical PS.

160 kmol CO2/minAdsorbent circulation rate 530 t/min

Working capacity of adsorbents

The Achilles Heel of Adsorption processes

Rotary Wheel contactor

Wheel : diameter 10m, depth 1m

1 minute regeneration time

8 wheels in parallel

Adsorbents


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A cage-like structure which admits onlymolecules less than a certain size e.g.13X (pore diameter 7) will admit He,H2, H2O, CO, CO2, N2

For CO2, there is also significant chemi-

Molecular sieves: ZeolitesAdsorbents

Type X or Y Zeolite

Cations ( e.g. Na+)

sorpt on to t e sur ace, w c g ves t erequired selectivity over other gases

Adsorbents


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Metal Oxide clusters connected by organic linkers

MOF-177 soaks up 140% of its weight in CO2

at roomtemperature and reasonable pressure (32 bar)

Metal Organic Frameworks (MOFs)Adsorbents

Li, J.R Coordination Chemistry Reviews 255 (2011) 17911823

Regeneration Options


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PSA : pressure swing adsorption Pressure is varied : high absorption,low desorption

Rapid cycle easily achieved Short cycle times possible: seconds

Regeneration Options

TSA : temperature swing adsorption T is varied : low absorption,

high desorption Rapid cycle requires very fast heat

transfer: difficult to achieve Minimum cycle time: minutes

Others VSA , vacuum swing adsorption:pressure is varied from a

vacuum to value above Patm ESA, electrical swing adsorption: a current is applied

cyclically to a conducting adsorbent such as a carbon

Adsorption technology issues


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Adsorption technology issues

Regeneration energy should be lower relative to solvents buteffects such asHeat capacityWorking capacityHeats of reaction needs consideration

Potential disadvantages:

Particle attritionHandling of large volumes of sorbentThermal management of large-scale adsorber vessels

Adsorption processes are still in the kW range of demonstrationCurrent development of new materials such as metal organicframeworks (MOFs), zeolites and zeolitic imidazolate frameworks(ZIFs) shows promising

GCCSI

Indice


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Absorcin Adsorcin



Membrane technology schematics


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gy

VENT GAS CO2

Separation of CO2 from flue gas by selectivelypermeating it through the membrane material

High permeability High selectivity

FLUE GAS GAS (CO2) POLYMER, METALLICOR CERAMIC MEMBRANE

CO2 permeation requires CO 2 partial pressure gradient across the

membraneOption 1: pressurizing the flue gas on one side of the membraneOption 2: applying a vacuum on the other side of the membrane

Option 3: both

Membrane technology issues


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gy

Claimed to potentially offer low energy capture processes

Small foot print for the capture system

Modular design that may allow for flexible operationTesting conducted at scales less than 1 t/day. No public results

Potential fouling of the membrane surfaces from particulatematter

Uncertainty about performance and cost of large-scale efficientvacuum pumps and compressors

Ability to integrate the process into a power plant

GCCSI

Types of membranes for CO2 removal


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1. First Generation:Cellulose acetate (Cynara, UOP, Grace)Polysulfone (Air Products Prism)

Generally spiral wound ~ 3,000 m2 per m3 volume2. Second Generation:

yp 2

o y m es e, Most likely hollow fibers ~ 10,000 m2 per m3 volume Alternatively spiral wound modules

3. Non selective membranes: gas liquid-contactorsLiquid solvent on one sideGas stream on the other side

Membrane Technology


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Spiral Wound Module

~ 3000 m2 per m3 volume

Source: CO2CRC, 2009

Membrane Technology


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Hollow Fibre Modules

~ 10,000 m2 per m3 volume

Fibre 0.1-0.5 mmSkin layer ~0.1 m thick


Membrane Technology


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Liquid solvent on one side of the membrane and the gasstream on the other side of the membrane

Gas-Liquid contactor

Membrane is not selective; only separates gas and liquid phasesDiffusion through porous followed by chemical absorption in liquidSize of the pores:

Flue GasMicroporousMembrane Absorption Liquid

CO2

CO2

membrane Small enough so that the liquid will not wet the pores

Membrane Technology


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Gas-Liquid contactor


Indice


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Absorcin Adsorcin



State of postcombustion development


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Absorption Adsorption Membrane

CommercialUsage in CPI* High Moderate Low/Niche

Operational Hi h Hi h but com lex Low to moderate

GCCSI* Chemical Process Industries

on ence

Primary Sourceof Energy Penalty

Solventregeneration

(thermal)

Sorbentregeneration

(thermal/vacuum)

Compression onfeed and/or vacuum

on permeate

DevelopmentTrends

New chemistry,

thermalintegration

New chemistry,

processconfiguration

New membrane,

processconfiguration

Indice


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Absorcin Adsorcin


Principales retos


Major challenges for postcombustion


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1. Reduction of the large parasitic load imposed on a power plantMostly derived from the energy needed to regenerate thesolventEnergy required for compression is less than that requiredfor capture

2. Development of new chemistry, new process designs, and

All aimed at reducing the energy penalty3. Capital cost reductions, solvent degradation, solvent volatility,

and other

Secondary to the prime issue of reduction in parasitic load4. Identification of amine derivatives and degradation products

effects on HS&ECountermeasures to be developed

GCCSI

Indice


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Absorcin Adsorcin


Principales retos


European demo projects


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BelchatowRotterdam 2

Post180 MDon Valley

180 M

JanschwaldeOxy-PC180 M

COMPOSTILLA

Oxy-CFB180 M

Pre180 M

Porto Tolle

Post100 M

x

? ?



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Rotterdam Capture: 1.2 MMt CO2/y Storage : depleted gas fields, N.Sea Industrial partners: EON/Electrabel

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