1. Introduction. 2. Concept. 3. Assumptions. 5. Conclusions

Transcription

1 TITEL-FOLIE 3 rd IEA Workshop on Aerosols from Biomass Combustion Jyväskylä (Finland), 3 September 2007 Cost of Particle Removal for 200 kw to 2 MW Automatic Wood Combustion by ESP and Fabric Filters Thomas Nussbaumer Zürich, Switzerland University of Lucerne, Technology and Architecture INHALT Kapitel 1 1. Introduction 2. Concept 3. Assumptions 4. Results 5. Conclusions

2 K, Ca, Na, Cl, S...! KCl, K 2 SO 4, CaCO 3 [Kaufmann & Nussbaumer 1998] 100 <0.41 K >12.21 Aerodynamic Diameter [µm] Aerodynamischer Partikeldurchmesser [µm] Ca PM [mg/m n 3 ] (13% O2 ) INHALT Kapitel 1 1. Introduction 2. Concept 3. Assumptions 4. Results 5. Conclusions

3 Separation efficiency of a tube ESP 100% 90% 80% Hoval 70% Abscheidegrad 60% 50% 40% 30% 20% 10% 0% Residence time Specific volume Durchmesser D = 150 mm, Spannung U = 20 kv Stromdichte j 920µA/m 2 = Coronastrom 130 µa an Drahtlänge von 300 mm d [!m] SCA [s/m] : E [kv/cm ] = 2.67 j [!A/m 2 ] = Increasing efficiency: Increasing residence time = increasing size Increase of voltage Reduction of distance between electrodes nach [N. Klippel, 8 th Int. Conf. on ESP, USA 2001 ] Particle precipitation Pre dedusting > 5!µm Fine particle removal < < 0,01!µm Cyclone Electrostatic Precipitator (ESP) Fabric filter (FF) + + Raw gas Clean gas Condensation! C-content < 2%

4 INHALT Kapitel 1 1. Introduction 2. Concept 3. Assumptions 4. Results 5. Conclusions Method of Annuity Heat production cost = Capital + Fuel + Operation cost Capital cost = Annuity x Investment cost Fuel cost = (Power / Efficiency) x Fuel price Operation cost = f (Investment cost, fuel type) respecting lifetime of filter of 5a, cost for power, press. Air, dp

5 Basic Assumptions Fuel Wood chips 3 Ct./kWh* Light fuel oil 6 Ct./kWh (60 Ct./l) Capital Interest rate 5% p.a. Calculation period 15 a / 30 a Operation Full load hours 2000 h/a PM after cyclone 200 mg/m 11 or 13% O 2 after precipitator < 20 mg/m 3 Carbon content < 5% for ESP < 2% for FF *[CARMEN 2006]: Ct./kWh INHALT Kapitel 1 1. Introduction 2. Concept 3. Assumptions 4. Results 5. Conclusions

6 Investment cost Investment cost [1000 Euro] Investment costs [1000 Euro] Technique w/o building and w/o precipitation Building ESP Fabric filter output [MW] Specific investment cost (without building) Specific Investment cost [Euro/kW] without building Specific investment costs w/o building [Euro/kW] 1800 Plant with ESP 1600 Plant with fabric filter 1400 Plant w/o precipitation

7 Increase of investment cost by ESP/FF Increase of investment costs for technique [%] [%] Increase of Total Investment Cost ESP Fabric filter Increase of heat production by ESP Cost for particle separation [Ct./kWh] [Ct./kWh] 4.0 Total cost ESP 3.5 Capital cost ESP 3.0 Operating cost ESP

8 Increase of heat production by FF Cost for particle separation [Ct./kWh] [Ct./kWh] 4.0 Total cost fabric filter 3.5 Capital cost fabric filter 3.0 Operating cost fabric filter Heat production cost from wood and light fuel oil Heat production cost [Ct./kWh] + 30% + 20% 50 mg/m 3 > % 20 mg/m 3 > % 20 mg/m 3 Wood with ESP Wood with fabric filter Wood with cyclone only Light fuel oil (CH) OAPC in Switzerland + 6% Fuel price Wood: 3 Ct./kWh Light fuel oil: 6 Ct./kWh (" 60. /100 l) Capital cost 5% p.a. for 15 years Operation with 2000 h/a

9 INHALT Kapitel 1 1. Introduction 2. Concept 3. Assumptions 4. Results 5. Conclusions Conclusions 1. Particle removal by ESP and FF is available and proven from 500 kw to 2 MW for a limit value of 20 mg/m 3 real emissions are typically < mg/m 3 and heat production cost increase by 6 12% 2. ESP exhibit higher investment cost, FF exhibit higher operation cost, resulting in almost equal total cost - not considering higher requirements for fuel quality in case of FF 3. Applications from 100 kw are possible, however, specific cost of equipment on the market increase dramatically < 500 kw, > cost reduction potential for < 500 kw

10 Conclusions 4. To guarantee high removal efficiency in practice, strong quality requirements are needed for combustion design and control and for plant planning and operation: Availability > 97% needs: - No On/Off and long stationary operation - Heat exchange varying with load to enable T > 120 C High burnout quality: 5% C for ESP, 2% C for FF Limited water content for FF Further experiences for < 1 MW needed 5. FF are more critical for carbon burnout, glowing particles and condensation. ESP are advantageous for wet fuels or difficult conditions, while FF can easily be applied for dry fuels and optional sorptive removal of HCl, SO 2, and PCDD/F. INHALT Kapitel 1 Acknowledments Federal Office for the Environment Office of Environment Canton Thurgau Download: Nussbaumer, Th.: Stand der Technik und Kosten der Feinstaubabscheidung für automatische Holzfeuerungen von 100 kw bis 2 MW. Zürich 2006, ISBN