Efficiency Improvement and Biomass. Robin Irons

Transcription

1 Efficiency Improvement and Biomass Robin Irons APGTF February 2009

2 CO 2 abatement from coal twin track approach Carbon -95% Dioxide Reduction TRACK 2 Carbon Capture and Storage (CCS) Track 2-60% Increased Efficiency, Biomass co-firing etc Track 1 TRACK 1-23% Baseline - - Source: IEA Possible Now Medium Term Long Term Time CO2-arme Kohlekraftwerke EEN-PMT Seite 2

3 Why must a power plant be highly efficient to guarantee economic operation of carbon capture? More fuel per kwh or a low efficiency means more flue gas The expense of CO 2 capture depends on the quantity of flue gas. So it is important to produce as little as possible flue gas per kwh. Besides: The higher the consumption of fuel the higher are the costs. Economic CO 2 capture depends on highest efficiency CO2-arme Kohlekraftwerke EEN-PMT Seite 3

4 Efficiency and cost implications of most CO 2 capture options. 60 % of plant output used in CO2 capture % of output used for capture Base power plant efficiency % Slide Courtesy RWEnpower CO2-arme Kohlekraftwerke EEN-PMT Seite 4

5 Efficiency of hard coal power plants worldwide Efficiency [%] 1) >50 China/ World USA Europe Germany E.ON Datteln 4 Power Plant Russia today Staudinger 650plus ) Average of new and old plants CO2-arme Kohlekraftwerke EEN-PMT Seite 5

6 Increasing efficiency up to 50% : step by step >50 % other feed water system low pressure turbine steam pressure 700 C/>350 bar steam temperature 700 C/250 bar condenser pressure flue gas heat recovery 46 % 600 C/250 bar CO2-arme Kohlekraftwerke EEN-PMT Seite 6

7 Coal fired Power Plant State of the Art / Aims of a 700 C Power Plant Parameter State of the Art Aims Steam pressure (bar) SH steam temperature ( C) RH steam temperature ( C) Net-Efficiency (%, LHV) nearly 46 > 50 CO 2 -emission (g/kwh) 720 < 660 Materials required Ferritic / Austenitic Nickel based CO2-arme Kohlekraftwerke EEN-PMT Seite 7

8 700 C Steam Pipe at Scholven Power Plant Seite 8

9 Material Thickness Temperature Material Material Thickness of Tubes 100,000 h Creep Strength (MPa) Ferritic steel Austenitic Steel Ni Base Alloy Temperature ( C) Change from Ferritic/Austenitic Materials to Nickel-Base-Alloys CO2-arme Kohlekraftwerke EEN-PMT Seite 9

10 COMTES 700 High Pressure Header (during installation) VIK-Arbeitskreis Energietechnische Zukunftskonzepte 09. November 2006 EEN-TTS Seite 10

11 Test Evaporator and Superheater in Boiler (view from below) 2 Superheater Evaporator Slide 25 Seite 11

12 Tubes and pipes Challenges of 700 C Life Steam Temperature Designed by Siemens Big valves Designed by Hitachi Power Europe Superheater and reheater Steam Turbines Designed by Siemens Seite 12

13 Pathway to USC 700 C Power Plant Material Developement COMTES700 NRWPP Demo Power Plant Experience, Know-How Seite 13

14 Fuel: Hard coal Capacity: 508 MW (net.) Live Steam cond.: 700 C/>35 Efficiency: > 50 % Consumption of fuel: 140 t/h CO 2 -Emissions: 670 g CO 2 /kw Heat transfer to LNG * is plan Status: capture ready Invest: > 1 Billion Euro Commissioning planned: 2014 Power Plant Project 50plus- World champion Next but one power plant 700-degree-technology: Highest efficiency worldwide * LNG : Planned Liquid Natural Gas Terminal CO2-arme Kohlekraftwerke EEN-PMT Seite 14

15 The price of Nickel $/ton One large supercritical boiler may use 2% of world s annual Ni production Source FT CO2-arme Kohlekraftwerke EEN-PMT Seite 15

16 Fuel Quality Impacts on Boiler Operation Erosion Heat Transfer Fouling and Corrosion Slagging Electrostatic Pollutant Precipitation Formation Flue Gas Combustion Desulphurisation Stability and Burnout Pollutant Emission Pf Pipework Erosion Mill Wear & Explosion Handleability CO2-arme Kohlekraftwerke EEN-PMT Seite 16

17 New Challenges for Corrosion El Cerrejon Air-Fuel 1.00E-09 95%ile Parabolic Rate (cm 2 s -1 ) 1.00E E E E E Temperature ( o C) T22 E1250 TP347HFG HR3C CO2-arme Kohlekraftwerke EEN-PMT Seite 17

18 New Challenges for Corrosion El Cerrejon Oxy-Fuel 1.00E-09 95%ile Parabolic Rate (cm 2 s -1 ) 1.00E E E E E Temperature ( o C) T22 T91 E1250 TP347HFG HR3C San25 IN740 CO2-arme Kohlekraftwerke EEN-PMT Seite 18

19 New Challenges for Corrosion Thoresby Oxy-Fuel 1.00E-09 95%ile Parabolic Rate (cm 2 s -1 ) 1.00E E E E-13 T22 T91 E1250 TP347HFG HR3C San25 IN E Temperature ( o C) CO2-arme Kohlekraftwerke EEN-PMT Seite 19

20 Type IV cracking in high alloy ferritic steel weld HAZs A life-limiting failure mechanism for ferritic steels in advanced plant Key questions How big a long term problem will Type IV creep cracking be? Will the strongest steel always have the strongest weld HAZ? Do we need to change our design practice? Can we eliminate the Type IV problem? CO2-arme Kohlekraftwerke EEN-PMT Seite 20

21 Direct Co-firing Options for Power Plant Original Cofiring involved co-milling of biomass and coal together For increased percentage of biomass, biomass is separately milled and fired through dedicated burners (eg Ferrybridge) or is injected into the pf pipe upstream of the Low NOx burner (Doosan Babcock at Drax) Burner design and biomass type critical to direct co-firing design Drax: prototype running for 2 years and installation on all 6 units underway to give about 10% biomass cofiring across the whole station. 20% limit recommended for retrofit Up to 50% co-firing possible on new supercritical plant, however, Mill control, furnace design and sootblower configuration require modification to accommodate higher co-firing rates. Fuel composition and co-firing level needs careful specification and control CO2-arme Kohlekraftwerke EEN-PMT Seite 21 Slide Courtesy Doosan Babcock

22 Fuel Quality Impacts on Boiler Operation Erosion Heat Transfer Fouling and Corrosion Slagging Electrostatic Pollutant Precipitation Formation Flue Gas Combustion Desulphurisation Stability and Burnout Pollutant Emission Pf Pipework Erosion Mill Wear & Explosion Handleability CO2-arme Kohlekraftwerke EEN-PMT Seite 22

23 The MatUK SRA Strategic - BIOMASS Research FOR Agenda ENERGY (SRA) for Energy PRODUCTION Materials, launched by the Energy Materials Working Group of MatUK in December 2007, identified the utilization of biomass for energy production as one of the key low carbon technology alternatives to fossil fuels. In the SRA, biomass firing was identified as being of high priority, because of: the modest technological risk involved, and the ready availability of waste biomass in many countries. CO2-arme Kohlekraftwerke EEN-PMT Seite 23

24 MatUK Strategy for Biomass for Energy Research Priorities The MatUK SRA identifies the major materials challenges facing biomass in energy processes and, therefore, the R&D priorities as: improved alloys and coatings for evaporator and superheater tubing in heat exchangers and hot gas paths of gas turbines/gas engines, Improved life prediction modelling for heat exchangers to optimize maintenance and repair procedures, monitoring of corrosion/contaminants to provide early warning of problems, and improved repair/refurbishment procedures for heat exchangers and CO2-arme Kohlekraftwerke EEN-PMT Seite 24

25 Current R&D Corrosion Modelling Modelling Fireside Corrosion of Heat Exchanger Materials in Advanced Energy Systems - Jan 2007 to Jan m Project, with 50% Support from the Technology Strategy Board (TSB) of UK Government, under the Materials Modelling Call - Autumn 2005 To develop validated boiler tube corrosion rate models in the complex and aggressive combustion-derived environments associated with advanced coal-fired power plants for low carbon energy generation. Partners: Cranfield University Doosan Babcock E.ON National Physical Laboratory RWE npower CO2-arme Kohlekraftwerke EEN-PMT Seite 25

26 Biomass Corrosion 316 SS specimen exposed at 658 C - 20% biomass (Cereal Co- Product) during 50 hour corrosion run exhibiting severe localised pitting attack CO2-arme Kohlekraftwerke EEN-PMT Seite 26

27 Some Materials Issues - Advanced Plants Ability to withstand temperatures up to 700 o C and P > 350 bar Corrosion Resistance - biomass combustion Corrosion Resistance - CO2/SO2-rich atmospheres Corrosion Resistance amine atmospheres Gas turbine blades - attack by trace species Gas turbine blades - effect of increasing temperature CO2-arme Kohlekraftwerke EEN-PMT Seite 27

28 APGTF R&D Areas - Efficiency and Biomass Basic and applied R&D Component and pilot scale HIGH MEDIUM Low HIGH MEDIUM Low Power Plant Materials topic Optimisation of cycles Gas turbine technology issues Multi pollutant control Flexibility of operation and control Open access test facility Co-use of Biomass Advanced cofiring or co-gasification Efficient preparation and processing Impact on capture processes Materials issues for biomass use CO2-arme Kohlekraftwerke EEN-PMT Seite 28