Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
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
3
4
Overview of SSE
5
6
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
7
Application of CCS to new build CCGT
New CCGT plant permit applications must demonstrate CCS readiness
8
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
9
• 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
10
For more information see The ‘Carbon Capture Readiness’ DECC guidance note
11
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
12
History of project
13
Project Execution
13
14
Overview of Peterhead Power Station
Peterhead Power Station CCGT Capacity 1180 MW 15
Peterhead History
16
1973 1980 1985 1991 1998 2010 NOW
Peterhead Power Station
17
Peterhead Power Station ‘Block 1’ CCGT
18
19
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
20
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
21
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
22
Overview of Full CCS Chain
23
Overview of Full CCS Chain
24
Capture Plant Location
25
Capture Plant
Location
Dense Phase Compression
GT13
Interfaces between Peterhead and CCP Plant
26
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
27
Steam Cycle Simplified – ‘Block 1’ CC2/3
28
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
29
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
30
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
31
New Steam Turbine ‘ST13’ options
32
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
33
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
34
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
35
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
36
Cooling Water
37
38
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
39
40
Thank you