Carbon Capture Readiness for CCGTs - · PDF filePost-2020 targets drive capture readiness ... auxiliary transfomer(s), switchyard and cable routes ... IMechE 20100518 CombinedCycleCaptureReadySummary.ppt

For internal use only. Copyright © Siemens AG 2008. All rights reserved.

Carbon Capture Readiness for CCGTs

Michael Rolls18 May 2010

2 18 May 2010 Energy Sector

Copyright © Siemens AG 2010. All rights reserved.

Post-Combustion for Combined CyclesDrivers and Development Challenges

Post-2020 targets drive capture readiness

Siemens pursues within the Statkraft CCS Study the developmentof a dedicated capture process for combined cycle power plants

• Compared with average emissions from installed global steam power plant capacity:specific CO2 reduction of 66%

• Compared with state of the art steam power plant emissions: specific CO2 reduction of more than 50%

• EU legislation calls for capture ready feature for new plants with an output > 300 MWe

Post-Combustion Development Challenges

• Low CO2 concentration in flue gas• High oxygen content in flue gas• Operation with frequent load changes• Fewer integration options for low temperature heat

from the capture plant



Steam from steam cycle

40-45°C 90-105°C

CO2 concentration 99% pressure 200 bar

approx. 120°C

Siemens post-combustion capture processCurrent development status

• Heating up solvent

• Desorption of CO2• Evaporation of

reflux water

High absorption rate

Stringent environmental requirements are easily met

Low degradation (O2)

Solvent slip nearly zeroSiemens CO2 compressorsolutions

Low energy demand



Ammonia

MEA

Amino acid Amino acid salt

CH

NCH

R

R’O

O

K+ -

NH

HH

CH

NCH

R

R’OH

O

Salts have no vapor pressure

Negative ion is less sensitive to O2

Amino acids are naturally present

• No thermodynamic solvent emissions

• Not inflammable• Not explosive• Odorless• No inhalation risk

• Low degradation• Biodegradable• Nontoxic• Environmentally

friendly

CH

2

NHOCH2

H

H

Amino acid salt is the basis of our solvent

Solvents based on amino acid salts are economic, have low environmental impact and are easy to handle.

No vapor pressure

Chemically stable

Naturally present



Further process improvements in several development fields are ongoing

Re-optimization of CCS plant for CCGT is showing good results

Improved design∆ η -9.2%pts.

2.7 GJ/ton CO2 for coal plants

Equipment Optimization

Efficiency

Investment CostsScale-Up

• Pressure drop• Type of equipment (e.g. packing)

• Size• Material

• Large distributors• Train concept • Heat integration

• Split loop configuration

Process ConfigurationProcess

Optimization

Power Plant Integration

Process Conditions

• Low temperature heat integration• Adaption of turbine operating characteristics

• Pump around• Desorber pressure• Process temp.

Solvent Optimization

Corrosiveness Chemical Stability

Kinetics

• Additives• Equipment material

• Additives• Structure of solvent

• Activation• Enhanced mass transfer

Capacity

• Concentration of AAS• Solubility• New functional AAS

Lab-proven



Carbon capture plantsComparison for different fuels

Coal/Steam Power Plant Gas/Combined Cycle Power Plant

Large power plant footprint

Low excess oxygen

High CO2 concentration

Small power plant footprint

High excess oxygen

Low CO2 concentration



Capture ready requirementsSiemens reference steam power plant

Steam turbines• extraction of approx. 40 % of LP

cross over steam• options for modification of turbines

depend on operation modes(part load, full load capability w/o CO2 capture, other plant and site conditions)

Steam turbine buildingsufficient space/foundation for:• modification of turbines• steam and condensate pipes• installation of heat exchangers

Our offer proposal:Our offer proposal:Integration of carbon capture unit into theIntegration of carbon capture unit into thepower plantpower plant““Capture Ready / Retrofit SolutionsCapture Ready / Retrofit Solutions””

FGD• either consider capacity

extension in column design• or provide space for

enlarged FGD unit

Air heatingOptional: space for installation of heat exchanger(s) for lowest grade heat utilization

Exhaust ducts• consider Δp from CO2

absorption unit • later flue gas connection to

capture unit (T-branch)

Flue gas fan• upgradeable design• or additional space for

installation of second fan downstream of FGD

Electrical auxiliary loadsufficient space for:• additional auxiliary transformer(s)• switchyard• cable routes

Condensate system,sufficient space for:• heat exchangers for low grade

heat utilization• additional piping routes with

supporting structure / racks

Cooling systemsufficient space for:• additional circulation pumps• service water system• sufficient cooling capacity of

cooling tower

Raw water & cooling water supply / Waste water treatment• sufficient space for enlargement• secure water utilization rights



Exhaust gas

Life steam

Condensate

4

98

10

Cooling tower

Coolingair

6 5 1 2 3

Air Fuel

Gas turbine plant:

11

12

7

9

Fresh water

1 Air intake2 Compressor3 Gas turbine4 Heat recovery

steam generator5 Generator6 Transformer

Steam turbine plant:7 Steam turbine8 Condenser9 Feeding pump

10 Generator11 Transformer12 Circulating pump

Capture ready requirementsSiemens reference CCGT design (2 + 1)

Steam turbines / Reheating adaptability for steam extraction, options for modification of turbines depend on required operating modes

Turbine building,sufficient space/foundation for modification of turbines, steam extraction and installation of additional equipment

Electrical auxiliary load,sufficient space for additional auxiliary transfomer(s), switchyard and cable routes

Cooling systemsufficient space for additionalcirculation pumps and service water system, sufficient cooling capacity of cooling tower

Condensate system,sufficient space for additional piping routes with supporting structure /racks

Raw water supply / Waste water treatment,sufficient space for enlargement, secure water utilization rights

Exhaust duct,consider laterflue gas connection to capture unit (T-branch)

Definition of capture ready measures requires insight into an appropriate capture process



TurbineHall area

Capture Ready RequirementsSteam supply options for single shaft SST-5000

LP Main Steam

Cold ReheatHot Reheat

Re-boiler CarbonCapture Plant

Steam extraction at low pressurelevel from the crossoverpipe possible

Extraction line routingmight require adaptationsin the turbine hall concept

Requires throttle flapin the crossover pipe



Steam turbines for combined cyclesSST-3000 SST-5000

Combined IP/LP turbine; axial exhaust Combined HP/IP turbine; lateral exhaust

Steam turbine concept influences optionsfor later capture plant retrofit.

Cooling and

module

concept

determine

ST design



Capture Ready RequirementsSteam supply options for single shaft SST-3000 & SST-5000

TurbineHall area

Re-boiler (carbon capture plant)

Optional Back Pressure Turbine

Not affected by capture ready /retrofitmeasures for process steam extraction

from steam cycle extraction



Conclusions

capture ready CCGT designs are ready now

no compromise is required to base plant performance

any additional plant costs for CCR are trivial (eg space provision)

future conversion requires ST blade path changes for lower flow

actual conversion impact depends on CCS technology status at thetime

Siemens amino acid salt solution applies for coal and gas plants

the CCS process is being optimised for CCGT flue gases

Documents

Carbon Capture Readiness for CCGTs - · PDF filePost-2020 targets drive capture readiness ... auxiliary transfomer(s), switchyard and cable routes ... IMechE 20100518 CombinedCycleCaptureReadySummary.ppt