Professor Raphael Idem Clean Energy Technologies Research

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Pre-combustion capture Professor Raphael Idem Clean Energy Technologies Research Institute University of Regina

IEAGHG Summer School 2015 University of Regina Saskatchewan, CANADA 18-22 July 2016

Faculty of Engineering & Applied Science

Modified from the Presentation of Professor Dianne Wiley UNSW, Australia IEAGHG Summer School 2015

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DEFINITIONS


1. Combustion

• Burning of fuel and oxidant to produce heat and/or work – fuel can be solid, liquid or gas – fuel can be fossil fuel or biomass (alone or used together)

• fuel + oxygen/air (O2) → carbon dioxide (CO2) + water (H2O) • + other gases (N2, SOx, NOx, CO) • + ash • + HEAT/ENERGY

Reaction


2. Gasification • Partial oxidation, oxidation and reforming of fuel and oxidant (with

limited O2) to produce syngas and heat – fuel can be solid, liquid or gas – fuel can be fossil fuel or biomass (alone or co-fired)

• fuel + oxygen/air (O2) + steam (H2O) → • carbon monoxide (CO) + hydrogen (H2) • + methane (CH4) + carbon dioxide (CO2) • + water (H2O) • + other gases (H2S, COS, NH3, HCN) • + ash + slag • + HEAT Syngas can be burnt or reacted further


Reaction

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Gasification reactions

Source: www.netl.doe.gov/research/coal/energy-systems/gasification/gasifipedia/reaction-transformations


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Gasification for chemicals production


Source: www.netl.doe.gov/technologies/coalpower/gasification/gasifipedia/6-apps/6-5-2_coal-to-derivative.html


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3. Reforming using CO2 Reformation Reactions

Hydrogen, Syngas from Bioenergy Solution gas

Pre-Combustion Capture

Gasifier

Electricity Generation

Water gas shift converter

CO2 capture process

Syn Gas H2 + CO

Water Gas

H2 + CO2 CO2

H2

Coal

Air/O2

Further purification and Compression for transportation,

storage and further use

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Pre-combustion capture • Capture CO2 for storage or reuse • Use water-gas shift reactor to maximize H2 production

– CO + H2O CO2 + H2

• Use H2

– combust in a combined cycle gas turbine plant to produce electricity – sell for distributed energy production – provide to fuel cell

• Similar processes apply to H2 production using – SMR (steam methane reforming) – ATR (autothermal reforming)


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Pre-combustion capture


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Example of IGCC power plant with capture

Source: Vatenfall


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Solvent absorption capture

• >> Animation of absorption process • www.co2crc.com.au/imagelibrary2/vid_ab

sorp_desorp.html


http://www.co2crc.com.au/misc/Schematic_1_animation/absorption_n_desorption_animation.html

Solvents for pre-combustion capture • Physical solvents

– Rectisol (methanol) • Lurgi and Linde, Germany • Lotepro, USA

– Purisol (N-methyl-2-pyrolidone: NMP) • Lurgi, Germany

– Selexol (dimethyl ethers of polyethyleneglycol: DMPEG) • Union Carbide, USA

• Chemical solvents – MDEA (Methyl diethanolamine (N-methyl-diethanolamine))

• Union Carbide, USA


Example of Coal gasification: Beulah, North Dakota, USA

• Dakota Gasification Company’s Great Plains synfuels plant • Gasification of lignite coal: 55 tonnes/h in14 Lurgi Mark IV

gasifiers operating at 1200°C – produces syngas and a range of chemical products

• synthetic natural gas • ammonium sulfate • fertilizers • phenol • cresylic acid • liquid nitrogen • methanol • naphtha, • krypton • xenon

Source: Dakota Gasification Company


Dakota gasification plant: CO2 removal • CO2 separated using solvent absorption

– Rectisol process (methanol) – pressure change regeneration

• 3 Mtpa CO2 – 96% pure, dry, oxygen and nitrogen free – transported 205 miles by pipeline to Saskatchewan, Canada – used for EOR

Source: Dakota Gasification Company


Map of transportation of CO2 from North Dakota to Weyburn, Saskatchewan


Physical absorption systems

http://netl.doe.gov/research/coal/energy-systems/gasification/gasifipedia/selexol Selexol


Selexol

Comments

• The solvent is not reactive • Pressure is needed to help the absorption process • Pressure release favors regeneration • Smaller amount of external heat is required


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IGCC: Kemper County, Mississippi, USA

• New 582 MWnet IGCC using TRIG™ technology air blown gasification

Selexol for H2S and CO2 removal

• Mississippi lignite coal • Capture

– 3.5 Mtpa CO2

– 65% capture rate – used for on-shore EOR – operational 2016

Source: Mississippi Power


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Advantages of pre-combustion solvent capture

• High CO2 concentration (for oxygen blown gasification) – large driving force for separation – easy separation requirements

• High flow-rate – large economies of scale

• Gasification is an established industrial process


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Challenges for pre-combustion solvent capture • High temperature (unless pre-cooled)

– increases materials degradation • High H2 concentration

– causes materials embrittlement • High flow-rate

– increases equipment size • High capital cost of gasification plant • Limited commercial-scale energy ~ 250 MW (more recently

437 MW) – expensive compared to conventional supercritical plants

• Difficult to retrofit to existing plant


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2nd & 3rd generation pre-combustion capture technologies

• Some technologies under investigation VSA or PSA (Vacuum or Pressure Swing Adsorption) SEWGS (Sorbent Enhanced Water Gas Shift) Gas separation membranes Low temperature separation IGFC (Integrated Coal Gasification Fuel Cell)

• Major focus on combined CO shift and CO2 capture Reduce capital cost Reduce energy penalty Reduce complexity


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Pressure swing adsorption


http://www.essentialchemicalindustry.org/chemicals/oxygen.html http://www.foxolution.co.za/psa-technology.php

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Comments

• Uses pressure to get one component to adsorb on an adsorbent relative to the other component

• The other component is produced as a relatively pure component

• The adsorbed component is then desorbed from the adsorbent by releasing the pressure


Port Arthur: VSA and PSA following SMR • CO2 separation with VSA followed by PSA

– concentrate CO2 from 10-20% to >97% – 90% recovery

• 1 Mtpa CO2 – used for EOR in Texas – first stage operational in 2012

Source: netl.doe.gov/File%20Library/factsheets/project/FE0002381.pdf


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Sorbent Enhanced Water Gas Shift Process

Refo

rmin

g &

Ca

rbon

atio

n

Rege

nera

tion

/ Ca

lcin

atio

n

Regeneration Gas

CO2-loaded Sorbent

Regenerated Sorbent

Hydrogen Regeneration Gas + CO2

Natural Gas & Steam

Sorbent Purge

Sorbent Makeup

Regeneration Energy


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Advantages of SEWGS • Process intensification

– simultaneous production of H2 and capture of CO2 with a combined sorbent catalyst

– eliminate shift reactor • Lower operating temperature

– reduce energy requirements – replace high temperature, high alloy steels in reformer – reduction or elimination of carbon deposition in reformer

• Potential cost reduction


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Challenges for SEWGS

• Issues with sorbent catalyst – decay in activity – sintering – attrition and fragmentation – control of competing reactions

• Ash fouling in the calciner 0 1 2 3 4 5 6 7 8 9 10

10

20

30

40

50

60

70

80

90

100

C N [%

]

Cycle no. [-]

0 1 2 3 4 5 6 7 8 9 10

10

20

30

40

50

60

70

g-CO

2 / g

-sor

bent

[%]

Havelock, 10% steamLongcliffe, 10% steamCadomin, 10% steamPurbeck, 10% steam

1 cycle 30 cycles

Source: Donat et al. (2012) ‘Influence of high-temperature steam on the reactivity of CaO Sorbent for CO2 capture’, Environ Sci Technol, 46: 1262-1269

Source: Abanades & Alvarez (2003) ‘Conversion limits in the reaction of CO2 with lime’, Energy Fuels, 17: 308-315


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Pre-combustion membranes • Process options

– membrane: H2 selective (metallic, porous inorganic, carbon, molecular sieve) or CO2 selective (polymeric)

– placement: before/between/within shift, during CO2 compression

• Advantages – compact and modular with no moving parts – low maintenance and highly reliable

• Challenges – high recovery of H2 – delivery of product at high pressure – membrane lifetime – scale-up

Source: ‘Integration of H2 separation membranes with CO2 capture and compression’ (2009) DOE/NETL-401/113009


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Low temperature separation

• Process conditions: -60°C • Advantages

– produces liquid CO2

– potentially low energy and cost – cooling can be provided by expanding feed gas – low temperature separation is a well established

technology • Challenges

– high recovery needs high pressure or hybrid process (e.g. with solvent capture)

– no pilot or demonstration yet

Source: Berstad et al (2013) Energy Procedia 37: 2204–2211


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Integrated Coal Gasification Fuel Cell • Advantages

– some fuel cells have high efficiency and use H2

– inherent CO2 capture if anode and cathode gases are separate

• Challenges – SOFC stack degradation – raise conversion efficiency

• reduce cell over-potential • higher methane content syngas

– full integration of SOFC stack to IGCC with capture not tested

Source: Keairns & Newby (2010) ‘Integrated gasification fuel cell (IGFC) systems’, 11th Annual SECA Workshop, Pittsburgh


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Technology status

Technology TRL Potential to reduce LCOE of capture

IGCC with selexol 9 +100% to 130% of baseline

H2 separation membrane with warm gas clean-up

5 -25%

SEWGS 5 -30%

Low temperature separation 2 -30%

Low temperature separation with CO2 recycle

2 -50%

IGFC 4-6 -70% to 95%

Adapted from: IEAGHG (2014) ‘Assessment of emerging CO2 capture technologies and their potential to reduce costs’ Report 2014/TR4


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Useful resources


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Documents

Professor Raphael Idem Clean Energy Technologies Research