Oxy-fuel combustion integrated with a CO 2 processing unit

Transcription

1 POLISH STRATEGIC PROGRAM ADVANCED TECHNOLOGIES FOR ENERGY GENERATION Oxy-fuel combustion integrated with a CO 2 processing unit coordinator: Wojciech Nowak AGH University of Science and Technology Kraków, Poland Ryszard Białecki Silesian University of Technology Gliwice, Poland

2 To reach technological readiness to demonstrate industrial scale power unit equipped with oxy-combustion boiler integrated with CO 2 sequestration. D e t a i l e d o b j e c t i v e s To recommend one out of three coal burning technologies (PC, CFB, PCFB) best fitting for oxycombustion technology. To evaluate modernization possibility of current power system by retrofitting operating/exploited units for oxy-combustion. To indicate development directions of clean coal technologies in Poland.

3 , budget 22M Wrocław University of Technology Częstochowa University of Technology Silesian University of Technology Wrocław University of Technology Institute for Chemical Processing of Coal Institute of Power Engineering Tauron - Power Station Łaziska PGE - Power Station Power Station Turów Foster Wheeler Energia, boiler manufacturer Eurol Innovative Technologies (SME)

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5 Combustion of single coal particle: normal and increased pressure ignition, pollutants, interaction with ash, comparison of different fuels Selected findings ignition time in air shorter than in oxy stable conditions of ignition in a laminar flow reached 536 C for coal and 520 C for lignite lower emission in oxy-combustion lower unburned content in oxy mode co-firing may be beneficial stabilized ignition when cofiring deposition rate of ash in oxy twice higher than that of air oxy atmosphere lowers the ash sintering temperature MSC ` O2 CO2

6 Experiments Measurements (flue gases concentrations time courses) Integration 13 main flue gas components In-furnace 4 levels Oxy-Fuel CFB Combustor VPSA-CO 2 Unit Range of investigations Factor Recommendations O 2 con. 30%-vol. or higher O 2 exc. between 5% - 15% Temp. ca. 850 o C Patent pending P : System for CO 2 capture in oxy-combustion of solid fuels in circulating fluidized bed boilers PG/SG insignificant impact

7 Corrosion tests 154 MW th CFB boiler Localization of measurement probes in the boiler design stage X8CrNi HR6W Samples of boiler steel

8 tests on PCFB 0,2 MW NOX and SO2 emission Pilot PCFB 0,2 MW th unit Pressure 5 bar O 2 /CO 2 = 30/70 reduction of emission compared to air Continuous transition from air to oxy-combustion the range of investigations: - pressure (0-8 bar) - O 2 fraction in oxidizer (up to 35%-vol.) o 50% reduction of SO 2 o 70% reduction in NOx

9 Pilot scale tests on 0,5 MW PC Power Engineering Institute, Warsaw O 2 /CO 2 atmosphere reduces combustion temperature if O 2 fraction <27%-vol Combustion time in O 2 /CO 2 shorter if O 2 > 21%-vol. Wet recirculation rises temperature and shortens combustion time Flue gas recirculation of RR=74% (heat exchange) Two designes of vortex burners fitted for oxy-combustion, both for retrofitted and new boilers Oxy-combustion reduces NOx emission (by about 25%) Oxy-combustion shortens the burn-out time of pulverized coal (by about %) allows combustion of coarser coal particles lower costs of fuel preparation higher net efficiency of power unit Patent pending: Method and burner for combustion of pulverized coal in concentrated oxygen flux experiments using Laser Induced Fluorescence

10 PSA technology on zeolite bed Membrane processes Patent pending Method of granulate production, especially perovskite structure compounds in thermal decomposition process of metal compounds with use of Spraypyrolysis apparatus with inner air heating system. Patent pending Method of oxygen separation out of air with use of perovskire collar-less pipe membranes

11 Mobile installation for oxygen separation VPSA-O 2 Pilot installation: - output: 100 m 3 N/h - oxygen purity: 95% - vol. - sorbents: zeolite molecular sieve, active Al 2 O 3 Adsorber, station valve and measuring system

12 Two-bed PSA installation Four-bed V-PSA installation Mobile four-bed DR-VPSA installation

13 Integrated VR model

14 identification of technical and economical risk factors risk evaluation connected with oxy-combustion power unit choice

15 Thermodynamic analysis allowed for optimisation of oxy-combustion power unit Final aftercooling of carbon dioxide with the use of absorption heat pump system Patent pending: Method of technical gasses compression, especially carbon dioxide Patent pending: Method of solid fuels drying quality improvement especially in power plant using oxycombustion Patent pending: Method of final after cooling of carbon dioxide with the use of absorption heat pump system Model of the separation

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17 adaptation of air furnace to oxygen without introducing changes in heating surfaces possible Population balance method of fluidized bed materials allowing for operation optimization of CFB boiler systems flue gas recirculation (68-74 %) power rate similar to air mode

18 LES and RANS simulation methods Temperature fields in various oxidizing atmospheres - simulation using Large Eddy Simulation method 21% O 2 /75% CO 2 35% O 2 /65% CO 2 A mean temperature in O 2 = 30% CO 2 = 70% RANS LES Possibility to apply developed mathematical models to design or adapt oxy-combustion PC and CFB boilers in industrial scale installations

19 Numerical model of oxy-combustion in CFB boilers separators Volume fraction of the solids phase in a CFB combustion chamber heat transfer surface primary O 2 secondary O 2

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21 Sustainable Development Index Sustainable Development Index ratio of cummulative exergy consumption and exergy of products boiler island steam cycle ASU CPU

22 Technological retrofit concept of power unit with OP-650 PC boiler coal boiler air desulphu -risation coal boiler O 2 N 2 ASU mill flue gases electro filter mill electro filter desulphu rization conden sate from steam cycle CO 2 cooling water inerts separation moisture separation

23 Full concept of retrofitting existing power units for oxy-combustion developed: - simulation models of installation - economic analysis of investment - schedule of implementation - risk estimation PC 200MW Air Oxy Water flux in cooler kg/s 8389, ,6 Make-up water flux kg/s 125,84 161,89 Gross power kw Net power kw Gross efficiency of power unit % Net efficiency of power unit % Boiler efficiency % 91,50 92,3 Internal load indicator % 7, Flue gas recirculation rate %

24 Technological retrofit concept of power unit with Ofz-425 CFB boiler O 2 N ASU 2 coal + sorbent boiler air coal + sorbent boiler electro filter electro filter conden sate from steam cycle cooling water moisture separation CO 2 inerts separation

25 Full concept of retrofitting existing power units for oxy-combustion developed: Technological retrofit concept of power unit with Ofz-425 CFB boiler - simulation models of installation - economic analysis of investment - schedule of implementation - risk estimation CFB 150MW Air Oxy Water flux in cooler kg/s 8389, ,6 Make-up water flux kg/s 125,84 161,89 Gross power kw , ,00 Net power kw Gross efficiency of power unit % 38,79 39,67 Net efficiency of power unit % 36,02 26,35 Boiler efficiency % 91,60 92,37 Internal load indicator % 7,12 33,58 Flue gas recirculation rate % ,34

26 Location of CO 2 capture installation key elements for 30 MWe scale

27 CFB Turow Power Plant case study CO 2 pipeline routes from PGE Turow Power Plants to geological structures in Kowalowo, Bogdaj and Radnica - CO 2 pipeline project alternative routes - CO 2 pipeline project option routes -Turow Power Plant - proposed locations of geological structures of CO 2 storage - Natura 2000 area

28 Development of oxy-fuel combustion technology in Poland

29 Conclusions What do we know? (1) CO2 quality tests and numerical simulations confirmed 80%+ CO2 purity without dedicated CPU system 99% CO2 purity possible if cryogenic or adsorption CPU system is applied Efficiency penalty & improvements 10% points efficiency penalty for not integrated plant (air-fired ref.) reduction to 7% points penalty possible by process integration and waste heat utilization further efficiency improvement by waste nitrogen utilization for coal drying or cooling purposes low excess oxygen and low NOx operation demonstrated high steam cycle efficiency makes integration more effective

30 What do we know? (2) Implementation perspective only larger scale projects still going ahead: Callide 100MW (Aus), FutureGen (USA) 167MW and White Rose (UK) 426MW China increasing interest large-scale tests needed for demonstration of integrated oxy-fuel plant concept flexible air- and oxy-mode switching possible CFD studies proved the possibility for oxy-fuel retrofit of existing boilers

31 What do we know? (3) Different technological options 5bar CFB pressurized oxy-coal tested» High efficiency» Good fuel flexibility» Retrofit and using existing turbo-machinery possible Oxy-Lignite - great potential for clean combustion» lignite moisture impacts the efficiency» Integrated grinding/dryer» less flue gas, smaller plant» idea for ASU-waste nitrogen use for lignite drying

32 What do we know? (4) example of optimization results lignite-fired PC boiler

33 What do we know? (5) Exemple of optimization results lignite-fired PC boiler Case Description number 1 reference oxy-fired unit 2 30% molar share of oxygen in oxidizer 3 heat recovery from flue gas and compressors intercooling to steam cycle 4 steam-driven compressors in ASU and compression train 5 heat recovery from the flue gas to combustion oxygen 6 lignite drying by preheated waste nitrogen 7 lignite drying by preheated air and waste nitrogen 8 wet recirculation of flue gas to boiler 9 partial replacement of CO 2 compression by CO 2 pumping, made possible by previous CO 2 condensation by water cooled in air-cooled tower 10 partial replacement of CO 2 compression by CO 2 pumping, made possible by previous CO 2 condensation by water cooled in air-cooled tower and nitrogencooled tower 11 combination of the above improvements that results in the highest net electrical efficiency of the power unit

34 What do we know? (6) Example of optimization results lignite-fired PC boiler Air-fired reference: 43,78 %