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Gas CCS in the UK

UK CCSRC Gas CCS Meeting

Sussex University25th June 2014

Tom Snow Design Development Engineer

Agenda

• Overview of SSE

• Application of CCS to new build CCGT plant

• Peterhead CCS Project

• Overview of Peterhead Power Station

• Overview of Peterhead Carbon Capture Process

• Interfaces between Peterhead Power station and the carbon capture process

• Conclusions

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Overview of SSE

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Wholesale – Generation• 11,500MW of electricity generation capacity in total (UK and

Ireland)

• Most diversity in fuel sources among UK generators

• 3,326MW of capacity for generating electricity from renewable sources

– Greater Gabbard Offshore Wind - 500MW

– Clyde Onshore Wind – 350 MW

– Hydro – 1500 MW

• 3,009MW of coal-fired capacity with biomass ‘co-firing’ capability

• 4,262MW of gas- and oil-fired capacity, including share of Marchwood, one of the UK’s most efficient gas-fired power stations

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Application of CCS to new build CCGT

New CCGT plant permit applications must demonstrate CCS readiness

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High level concept report typically prepared considering:

• Choice of capture technology – Post combustion scrubbing with amine

• Indicative CCS plant layout

• Pipeline route and storage site

• Economic assessment

CCS readiness

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• Exhaust duct take off

• Adaptability of steam extraction from steam turbine to supply CCS re-boilers

• Sufficient space in turbine building to allow for steam extraction and installation of additional equipment

• Provision for additional electrical auxiliary load

• Provision for additional cooling duty

• Raw water supply and waste water treatment

CCS readiness

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For more information see The ‘Carbon Capture Readiness’ DECC guidance note

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Peterhead CCS Project

• July 2012 – Shell & SSE initial Bid toDECC

• October 2012 – DECC down select 4Bidders to take through the BidImprovement Process (BIP)

• January 2013 – Shell submittedImproved Bid on behalf of Shell & SSE

• March 2013 – Peterhead CCS and WhiteRose Projects selected by DECC to takeforward

• February 2014 – Negotiations finalisedwith DECC and FEED contract signed

• March 2014 – FEED contractcommences

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History of project

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Project Execution

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Overview of Peterhead Power Station

Peterhead Power Station CCGT Capacity 1180 MW 15

Peterhead History

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1973 1980 1985 1991 1998 2010 NOW

Peterhead Power Station

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Peterhead Power Station ‘Block 1’ CCGT

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Overview of Peterhead Carbon Capture Process

Why CCS at Peterhead, Why in Scotland?

Capture at Peterhead

• Existing Grid Connection, Utility capacity and fuel supply

• Existing available land

• Workforce

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Why CCS at Peterhead, Why in Scotland?

Transport and Store • Existing Pipeline Infrastructure

• Existing Platform (Goldeneye), Wells and Reservoir

• Goldeneye reservoir well studied – Good candidate for storage of CO2

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Overview of the Peterhead CCs project

• CO2 capture from one gas turbine flue gas stream (GT13) at Peterhead power station.

• ~400MW post combustion retrofit

• Capture rate of 1m tonnes p.a. for anticipated 10-year period

• Capacity for at least 20m tonnes CO2 in the Goldeneye reservoir with significant expansion potential in the aquifer

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Overview of Full CCS Chain

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Overview of Full CCS Chain

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Capture Plant Location

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Capture Plant

Location

Dense Phase Compression

GT13

Interfaces between Peterhead and CCP Plant

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CCS steam requirements and options of supply

• CCS steam requirements ~50% Low pressure steam (3.5bar/150oC)

• Utilise block 1 in current configuration with minimal changes to the steam turbine

• Block 1 steam turbine re-sizing

• New steam turbine

• Positioned on the existing unit 2 plinth

• A standalone new steam turbine house

• A boiler

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Steam Cycle Simplified – ‘Block 1’ CC2/3

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HRSG LP steam

Unit 1 Steam Turbine

• U1 is a 660 MW GEC machine. Two main process/mechanical constraints – HP and LP stages

• HP swallowing capacity too large for low ‘CC1’ steam flow rates

• Risk of windage heating, HP exhaust trip level 420oC, P.R < 1.4

• CS cold reheat pipework creep damage risk

• LP cylinder (2x double-flow, LD66 7.8 m2 annuli), 20% recommended minimum exhaust flowrate:

• Last stage blade vibration leading to fatigue cracking

• Casing and blade overheating due to windage

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Unit 1 Steam Turbine Resizing and CCS

• HP constraint will be addressed by HP/IP resizing (Contract signed)

• CC1 will be possible, GT min load LP exhaust flowrate (just) > 20%

• But, if CCP steam extraction taken, LP flowrates < 20%

• Sensitivity of low flows on LD66 37” blades has recently increased with issues elsewhere in the fleet

• Conclusion: CC1+CCP not recommended on U1

• LP resizing considered but ruled out due to wide operating range required: CC1+CCP to CC3 no CCP

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Unit 1 Steam Turbine Resizing and CCS

• CC2/CC3+CCP operation possible, but which steam source?

• IP/LP crossover pipe not practical, size and location

• IP (HRH) steam 15 bar minimum

• Not very efficient way to supply LP steam to CCP

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New Steam Turbine ‘ST13’ options

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Steam turbine operational regime post CCS• New Steam Turbine ST13

• Operating in ‘CC1’ mode with GT/HRSG 13

• Steam extraction from IP/LP crossover

• Remainder of Block 1 to operate in CC1 or CC2 modes

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Gas Turbine Exhaust Gas

• GT exhaust gas

• Quite Important for the process with its CO2

• Tapping downstream of HRSG with booster fan

• GT13 flue left open with Fan pressure control, some leakage ‘up or down’ inevitable, but lower risk for HRSG ductwork integrity

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Selective Catalytic Reduction

• Shell wish to minimise NO2 to reduce amine solvent degradation and production of by-products

• HRSG is ‘SCR ready’ with space

• ST design pressure influencing factor on flue gas temperature

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Cooling Water

• Current abstraction licence based on 2x 660MW Rankine Units gives flexibility

• Block 13 and Block 1

• CCP and Compression & Conditioning Plant

• Various options still under investigation, all involve new pipework to CCP

• Upgrade CW pump(s) for higher head, including extensive modifications in ‘pit’

• Unmodified CW pumps, retain condenser philosophy of syphonic system, more complicated CCP cooling circuits

• Unmodified CW pumps with CCP booster pump station

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Cooling Water

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Conclusions

• CCGT Technology has an important part to play to help meet the UK’s electricity demand in a ‘low carbon’ future

• CCS on CCGT technology must be demonstrated to prove technology at an industrial scale

• If demonstration successful there is potential for further roll out• Work undertaken to date by SSE/Shell confirms the suitability of

Peterhead PS to provide necessary materials and interfaces for a CCGT CCS demonstration project

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Thank you