Electrostatic Precipitators For Small

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Central European Biomass Conference (CEBC), 26.-28.January 2011 in Graz IEA Task32-Workshop: “Fine particulate emissions from small-scale biomass furnaces“ Electrostatic precipitators for small-scale wood combustion systems – Results from lab- and field tests Hans Hartmann, Peter Turowski, Susanne Kiener Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe (TFZ), Straubing Hartmann P 11 B Ha 001 Folie 1 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Structure • Overview on small-scale particle separators • Field test with 3 ESP-types • Results from test stand trials (4 ESP‘s) • Summary and conclusions Hartmann P 11 B Ha 001 Folie 2 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Overview on particle separator types for residential applications Principle Advantage Disadvantage Electrostatic precipitator (ESP) low pressure drop, low cost problems with organic particles Filtering separators good separation effect (e.g. baghouse filters) high pressure drop, high technical efforts Cyclone separators low cost low effect on fine particles Scrubber flue gas condensation possible high technical efforts medium separation effect Flue gas condenation additional heat gain low separation effect Catalyst effect on gases, lower Corg load on particles very low separation effect Hartmann P 11 B Ha 001 Folie 3 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Configuration of ESP‘s Chimney-top separators Separators for flue gas tube integration (living rooms) Separators for central heating boilers ESP-chimney systems Hartmann P 11 B Ha 001 Folie 4 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Chimney-top ESP (1): Applied Plasma Physics (Norway)       Type: APP Residential ESP Cleaning/maintennance from chimney top effective length : ca. 1 m High voltage; max. 33 kV No active mechanical removal of PM deposits Status: development high voltage supply line Graph: APP part of precipitator above the chimney outlet Hartmann P 11 B Ha 001 high voltage electrode part of precipitator inside the chimney Photos:TFZ Folie 5 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Chimney-top ESP (2): OekoTube (by OekoSolve, Liechtenstein)     Type: Oekotube no active removal of deposits max 70 kW heat power output Status: market available (only Switzerland) Photos / Image: Oekosolve Hartmann P 11 B Ha 001 Folie 6 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Chimney-top ESP (3): Ruff-Kat GmbH, Holzkirchen       Type: Ruff-Kat Chimney mounted Voltage: 20 kV Mechanical removal of deposits (vibration) Length: ca. 1 m above chimney opening Status: Certified, field test Weather protection Precipitation zone Isolation Inner tube (springs) Vibrator for cleaning Electronics Ionisation zone cleaned uncleaned High voltage electrode Separation surface (inner walls) Mounting plate Photos / Image: Ruff-Kat Hartmann P 11 B Ha 001 Folie 7 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Boiler attached ESP (1): Spanner SFF (by Fa. Spanner Re²)        Types: Spanner SFF 20 / SFF50 / SFF100 Mounted beside a boiler Voltage: 15 kV Mechanical removal of deposits (vibration) With purge air cleaning of electrodes Pressure drop: 40 pa Status: Field tests 4 depositing pipes with electrode casing purge air cylinder raw gas electrode clean gas pipe -cleaning (vibration) absorber pipes purge air cylinder particle container Photos: TFZ Hartmann P 11 B Ha 001 Folie 8 Werkbild : Spanner Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Boiler attached ESP (2): Carola – Separator (by KIT, Karlsruhe)        Type: CAROLA (Develpment: Karlsruhe Institut of Technology) Mounted beside a boiler Mechanical removal of deposits (rot. brush, 1 min/h) Pressure drop: 10 pa Voltage 16-18 kV Tested with up to 30 kW Status: development Images: KIT Hartmann P 11 B Ha 001 Folie 9 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Boiler attached ESP (3): AL-Top (by Schräder, Kamen)  Type: AL-Top, ESP with infill of wetted metal shavings as absobing surface  Mounted beside a boiler  Status: development clean gas spray nozzle injection metal shavings infill (absorbing surface) high voltage electrode raw gas drain outlet Images: Schräder Hartmann P 11 B Ha 001 Folie 10 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Integrated ESP (1): ”Airbox” by Spartherm Feuerungstechnik      Type: Airbox (for fireplace inserts), Supplement exclusively for manufacturer ‘s furnaces (>15 kW) Plate-type ESP, manuelly switched-on Manual removal of PM deposits required after 100 h operation Status: market-available Photo / Images: Spartherm Hartmann P 11 B Ha 001 Folie 11 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Integrated ESP (2): Zumikron (by Rüegg, Switzerland)  Type: Zumikron Developed by Rüegg (Switzerland), built by: Kutzner+Weber  Mainly for single room heaters  Use of purge air for electrode cleaning  Manual removal of PM deposits required  Status: market-available (only Switzerland) Photo / Images: Rüegg Hartmann P 11 B Ha 001 Folie 12 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe ESP-Chimney-type: Feinstaubkiller (by TH-Alternativ-Energie)  Type: “Feinstaubkiller“ (ESP-chimney)  Electrode over full length of chimney  Automatic periodic cleaning by rinsing with water from surge tank High voltage power supply  Particle removal as sludge deposit  Status: single built and single approval Water injection for cleaning the inner tube of the chimney Special isolation for fixing the high voltage electrode Chimney made of stainless steel Electrode made of special type of wire Temperature sensor Cleaning door Boiler Photos: TFZ Hartmann P 11 B Ha 001 Special isolation and fixing the high voltage electrode with a spring Neutralisa tion box with pump for cleaning circuit Outlet for cleaning water and condensate Image: TH-Alternativ-Energie Folie 13 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Procedure of field tests performed by TFZ • Selection of 10 private households • Assembling of filters and automatic data recording (electricity consumption, operating hours) • Instruction of users concerning documentation • Continuous operation of ESP‘s during heating period 2008/2009 • Regular cleaning and observation by chimney sweep • Collection of deposited ash from the chimneys and the ESP‘s over the full period and • Determination of fuel consumption Hartmann P 11 B Ha 001 Folie 14 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe ESP-types applied in field test (1) APP Residential ESP, example here: with chimney stove (6 kW) Photos: TFZ Hartmann P 11 B Ha 001 Folie 15 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe ESP-types applied in field test (2) K&W Zumik®on, example here: with cooking stove (6 kW) Photo: TFZ Hartmann P 11 B Ha 001 Photo: TFZ Folie 16 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe ESP-types applied in field test (3) Spanner SFF 20 • example here: with log wood boiler, 15 kW • mechanical cleaning was here activated manually by press button Photos: Ritt Hartmann P 11 B Ha 001 Folie 17 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Observations from field tests Observed failures/troubles:  short circuits  failure of electrode purge air supply  burn-out of fuses  display failure  breaking of electrode  fixation problems (at chimney top)  sensor defects  high voltage failure  chimney draft problems  rain water intrusion into chimney  counteraction of ESP-purge air with furnace air supply  noise harassment Hartmann P 11 B Ha 001 Folie 18 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Results field tests: electrical power input APP Residential ESP KW Zumikron Spanner SFF20 200 electrical power input 180 160 W 120 80 47 40 28 14 11 3 0 Betrieb operation Hartmann P 11 B Ha 001 Standby-Betrieb stand-by Folie 19 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Field test results: Calculated particle reduction Participant Furnace ESP-type Fuel log wood (spruce, pine) log wood (spruce, pine) log wood (spruce, pine, beech) Collected particle massb) Theoretical reduction of PM emissionc) 0.18 kg 9 mg/m³ 2.38 kg 54 mg/m³ 0.06 kg 5 mg/m³ 0.30 kg 17 mg/m³ 0.36 kg 52 mg/m³ 0.83 kg 25 mg/m³ 3.60 kg 122 mg/m³ 1 Chimney stove K&W Zumikron 2 Chimney stove K&W Zumikron Kitchen stove K&W Zumikron 5 Chimney stove APP Residential ESP log wood (beech) 6 2 Chimney stoves APP Residential ESP 7 Tiled stove 8 Log wood boiler 9 Pellet boiler Spanner SFF 20 Wood pellets 0.15 kg 5 mg/m³ 10 Wood chip boiler Spanner SFF 50 Wood chips 18.59 kg 158 mg/m³ 4 a) a b c log wood (spruce, pine) log wood APP Residential ESP (spruce, pine) log wood Spanner SFF 20 (spruce, pine) Only ash from connecting pipe and ESP because further furnaces were connected to the same chimney Particle mass in ESP + connecting pipe + chimney Calculated from fuel mass and specific flue gas volume, based at 13 % O2 Hartmann P 11 B Ha 001 Folie 20 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Field test results: Investigation of PAH-content in PM deposits  Materials with more than 50 ppm PAH are considered as cancerogeneous in Germany  Above 1000 ppm they are considered as dangerous waste. PAH-contents of PM collected from connecting pipes + ESP + chimney Participant Furnace Separator 1 2 chimney chimney stove stove K&W K&W 3 4 5 Hartmann 7 8 9 10 pellet boiler wood chip boiler tiled stove kitchen chimney chimney stove stove stove tiled stove log wood boiler K&W K&W APP Spanner Spanner Spanner APP Total PAH 183ppm 744ppm 1344ppm 922ppm 66ppm P 11 B Ha 001 6 Folie 21 APP 470ppm 1713ppm 380ppm 21ppm 197ppm Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Trials performed at TFZ test laboratory • Selection of 2 suitable chimney stoves (a simple and a high value product) • Tests with of 2 ESP‘s (Zumik®on and APP) at both stoves 4 test series • Tests with Spanner SFF20 at log wood boiler (simple natural draft type) • Test duration: 5 to 6 weeks per test series (typical operation) • Weekly measurements of particle separation in raw and clean gas (gravimetric determination) • Additional trials with ESP-chimney type by “TH-Alternative Energie“ Hartmann P 11 B Ha 001 Folie 22 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Additional tests: ESP-chimney system by TH-Alternativ Energie Water injection for cleaning the inner tube of the chimney Special isolation for fixing the high voltage electrode High voltage power supply Chimney made of stainless steel Electrode made of special type of wire Temperature sensor Cleaning door Boiler Special isolation and fixing the high voltage electrode with a spring Neutralisa tion box with pump for cleaning circuit Outlet for cleaning water and condensate Image: TH-Alternativ-Energie Hartmann P 11 B Ha 001 Photo: TFZ Folie 23 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Test stand setup  Dilution ratio: 1 : 4 – 6  Diluted temperature: < 52 °C  Gravimetric PMdetermination  Measuring over the full batch  3 fuel batches per trial Hartmann P 11 B Ha 001 Folie 24 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Test stand results: Zumikron ESP with simple-type chimney stove 80 70 Raw gas Clean gas Separation 70 % 60 33 500 Total PM emission Mean separation: 11% 400 37 19 20 29 10 300 18 200 8 9 50 40 30 20 7 100 10 0 0 2 0 -100 -5 -200 -2 - 10 - 20 - 15 -300 - 30 -400 - 40 - 45 -500 - 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Test No Hartmann P 11 B Ha 001 Folie 25 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Separation efficiency 800 mg/m³n 700 (13 % O2) 600 Test stand results : APPResidential ESP with simple-type chimney stove 1.000 Raw gas Clean gas Separation (13 % O2) 800 88 89 79 78 80 % Total PM emission 69 Mean separation: 55 % 600 58 51 60 54 48 50 48 41 44 400 40 29 200 11 20 11 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Test No Hartmann P 11 B Ha 001 Folie 26 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Separation efficiency mg/m³n 100 93 Test stand results : Spanner SFF 20 with log wood boiler (simple natural draft) 80 mg/m³n 200 (13 % O2) Total PM emission 96 61 100 94 69 66 150 88 55 50 % 80 60 40 37 100 50 86 40 11 20 0 0 -50 - 20 Mean separation: 25 and 80 % -100 - 40 - 41 -150 - 60 -200 Raw gas Clean gas Separation - 89 - 80 -250 - 100 1 2 3 4 5 6 7 8 9 Operation without by-pass Hartmann P 11 B Ha 001 Folie 27 10 11 12 13 14 15 Operation with bypass Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Separation efficiency 250 Test stand results : TH Feinstaubkiller with log wood boiler (simple natural draft) 300 100 Raw gas Clean gas Separation 89 mg/m³n (13 % O2) 81 90 94 240 Total PM emission Mean separation: 64 % 61 59 180 60 46 120 40 32 26 60 Separation efficiency % 80 20 0 0 1 2 3 4 5 6 7 8 9 Test No Hartmann P 11 B Ha 001 Folie 28 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Summary and conclusions • Three of four ESP‘s showed acceptable PM separations in both, field and laboratory tests. • An active mechanical cleaning of the deposited particles seems inevitable for an undisturbed ESP-operation. • Bevor market introduction the observed failures should be avoided reliably. • An installation in living rooms is not accepted by the residents. • Specific rules for handling and disposal of collected PM-mass need to be elaborated due to the observed high PAH-contents. • For determining the separation efficiency, a reliable and repeatable test method needs to be elaborated. Hartmann P 11 B Ha 001 Folie 29 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe Download of the complete research report (in German language): TFZ-report No. 23 www.tfz.bayern.de Thanks for listening ! Hartmann P 11 B Ha 001 Folie 30 Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe