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TU Bergakademie Freiberg I Department for Energy Process Engineering and Chemical Engineering
Reiche Zeche I 09596 Freiberg I Germany I Phone +49(0)3731/39 4511 I Fax +49(0)3731/39 4555
Email [email protected] I Web www.iec.tu-freiberg.de
Department for Energy Process Engineering and Chemical Engineering
The University of Resources. Since 1765.
Thermodynamic and Economic Evaluation of IGCC-concepts with Carbon Capture
Mathias Riegera), Karsten Riedlb), Bernd Meyera)
a) TU Bergakademie Freiberg, IEC, Freiberg (Germany)b) E.ON New Build and Technology, Gelsenkirchen (Germany)
5th International Freiberg Conference on IGCC & XtL Technologies Leipzig, 21–24 May 2012
E.ON Energie AG E.ON New Build and Technology GmbH
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Contents
Thermodynamic and Economic Evaluation of IGCC-concepts with Carbon Capture
Background
Motivation
Investigated topics
Selected results
General conclusion
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Background
Cooperation with E.ON Energie AG
Significant share of hard coal fired plants in E.ON’s fleet
E.ON is committed to reduce the company’s CO2-intensity
E.ON invests in developing CCS technologies within a diversified R&D portfolio
Investigations in Carbon Capture IGCC (CC-IGCC) as one CCS option
Objective
Assessment of gasification technologies for hard coal
Development of CC-IGCC concepts on a common basis
Detailed performance calculation and loss analysis
Utility driven cost analyses
Approach
Development of sophisticated generic process simulation models for all major sub-processes
Economic evaluation based on published cost data
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Motivation
High fluctuation ofperformance data forconcepts based on thesame type of gasifier
Partially opposed studyresults
Low level of providedmodeling detailsprevents the causeanalysis for the varietyof results
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Investigated topics
1. Assessment of industrial gasification technologies
Preference technologies for hard coal fired CC-IGCC: GE-R, CoP, SCGP, Siemens
Performance evaluation and estimation of specific parameters
2. CC-IGCC based on preference gasification technologies
Individual concept development
Thermodynamic simulation of all major sub-processes
Analysis of performance disparities
Economic evaluation using the discounted cash flow method
3. Optimization of performance and economics
Effects of integration between the gas turbine and the ASU
Impact of reduced CO2-capture rates (e.g. through a one-reactor CO-shift)
IGCC-concepts without CO2-capture
CC-IGCC with minimal integration (only one interface between fuel gas generation and CCPP)
Co-gasification of biomass
CC-IGCC for lignite
Polygeneration IGCC buffering fuel for peak load electricity production
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Selected results: General layout for the CC-IGCC
The interfaces between the water-/steam cycle and the other sub-systems are not shown
Gasifier
(inclusive coal
preparation)
Air separation
unit
(high pressure)
coal
air
oxygen
raw
gas
converted
gas
CO-shift
(2-reactors with
heat recovery)
sulfur
carbon
dioxide
AGR
(solvent: MeOH)
nitrogen
(at dry coal
entry systems)
SRU + TGT
CLAUS
gas
tail
gas
clean gasnitrogen
(for clean gas dilution)
AGR … Acid gas removal
SRU … Sulfur recovery unit
TGT … Tail gas treatment
GT … Gas turbine
CO2-
compression
LP CO2 IP CO2
Water steam
cycle (3-
pressure reheat)
Combined Cycle Power
Plant (CCPP)
GT exhaust
Gas turbine
(F-class)
moisturized, diluted
fuel gas
air
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Selected results: Gasifier
Conclusion
Raw gases from slurry gasifiers produce a considerable amount of CO2
CH4-content of the CoP-raw gas will yield to higher CO2-emissions
Roughly 22 – 25 % of exergy losses at the first sub-process of the CC-IGCC
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Selected results: CO-shift
Conclusion
Gases generated by water quench gasifiers (GE-R, Siemens): Cycle with steam generation
Gases generated by gasifiers with convective cooler (CoP, SCGP): Cycle with cooler and saturator
Steam addition may be necessary to increase CO-conversion and to prevent catalyst overheating
Raw gas generated by the SCGP gasifier Raw gas generated by the GE-R gasifier
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Selected results: Acid gas removal
Conclusion
The CO2-partial pressure is thedecisive factor for the auxiliary loadof the AGR
The AGR for the IGCC with GE-Rgasifier has a noticeable lowerauxiliary load demand than at theother three concepts (due to thehigher gasifier pressure)
Gas originally generated by GE-R gasifier
Gas originally generated by SCGP, CoP or Siemens gasifier
Auxiliary load for the Acid gas removal unit
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Selected results: IGCC – gas composition
Gas composition at important process steps
steam supply
≈ 85 % CO-conversion
≈ 93 % CO-conversion
dilution with H2O and N2 to 45 % H2
CO2/H2S -removal
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Selected results: IGCC – performance
Conclusion
Minor performance differences with slight advantages for the CC-IGCC with CoP gasifier
ASU is responsible for the highest decrease of efficiency (not required N2-demand for slurryfeed gasifiers reduces the decrease of efficiency caused by the ASU)
Efficiency of CC-IGCC based on different gasifiers Auxiliary load fraction
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Selected results: IGCC – economics
Cost of electricity (CoE)
Influence of improvements
Marginal differences between the investigated CC-IGCC based on different gasifiers,especially under consideration of the resulting absolute amount of the CoE
Capital expenditures are the main cost drivers (responsible for roughly 60 % of the CoE)
CapEx reduction is the key; availability improvements are helpful; efficiency less important
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General conclusion
Cost of Electricity at the level of gas fired peak load stations
IGCC are not qualified for cycling operation but for base load
Mismatch between Cost of Electricity and power plant load profile
Investigated IGCC concepts are (today) not economic
for electric power production.
Achieved targets
Understanding of general technical coherences for CC-IGCC
Assessment (thermodynamics, economics) for a diversity of IGCC concepts
Identification of weak points and optimization parameters
Detected problem
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Thank you for your attention.
Contact: Dipl.-Ing. Mathias Rieger; [email protected]
Dr.-Ing. Karsten Riedl; [email protected]
Thermodynamic and Economic Evaluation of IGCC-concepts with Carbon Capture
