Tailor-made SNCR to Meet Future Emission Standards for Power Boilers

Transcription

1 Tailor-made SNCR to Meet Future Emission Standards for Power Boilers POWER-GEN Europe Amsterdam (June 9-11, 2015) Mehldau & Steinfath Umwelttechnik GmbH, Alfredstr. 279, Essen POWER-GEN Europe 2014 POWER-GEN Europe 2015 Bernd von der Heide

2 Influences on Performance of SNCR Design of the Combustion Chamber Boiler Design Position of the Heat Exchangers Design and Configuration of the Burners Operating Conditions in the Boiler Type of Fuel Reagent - Urea Solution or Ammonia Water

3 Developments to improve SNCR Performance Switching of individual lances Variation of Water Flow TWIN-NOx Process Cooling of Flue Gases Extrapolation of Flue Gas Velocity

4 Process Flow Diagram of a Simple SNCR Plant Reagent Storage Combustion Grate

5 NO x Reduction - Influence on Temperature Window Range for NO x /NH 3 - optimized operation Range for SNCR and SCR operation A B Optimum temperature for SNCR alone (low ammonia slip) Optimum temperature for SNCR and SCR (high ammonia slip)

6 Injection Concepts and Configuration of Injection Lances zepte The changing of individual lances following the temperature profile results in: High efficiency Low NO x emissions Low NH 3 slip < 10 mg/nm³ Low consumption of reagents Low CO emissions POWER-GEN Europe 2015

7 SNCR Plant Designed for High Performance Storage Tanks M & M Module Incinerator and Boiler

8 NO x at Stack [mg/nm³] Long Term Performance of SCNR Plant in WtE Wijster, NL

9 Impacts of Boiler Designs on Temperature Profiles Two Pass Boiler Temperature Profiles Tower Boiler

10 SNCR Process Urea vs. Ammonia Water Urea Solution Delayed reaction because urea particles need to be decomposed first Ammonia Water Due to high volatility reaction takes place immediately after injection

11 TWIN-NO x Combination of Ammonia Water and Urea Solution Effective temperature window can be Expanded by combining both reagents or Shifted by applying both reagents separately POWER-GEN Europe 2015

12 TWIN-NO x Process Fire Tube Boiler Ammonia Water Urea Solution Mixing & Metering Module

13 Injection of Ammonia Water and Urea Solution ~ 100% Boiler Load NH 4 OH NOxAMID Raw Gas NO X ~ 230 mg/nm 3 NO X Emission NO X Urea vs. NH 4 OH ~ 50 mg/nm 3 NO X ~ 180 mg/nm 3 No Injection Ammonia Slip Ca. 5 minutes delay from time of injection to measuring

14 TWIN-NO x Temperature Profile and Flue Gas Flow Design Data Flue gas flow max. Boiler load Thermal output 227,000 Nm³/h dry 240 t/h 160 MW NO x without SNCR 450 mg/nm³ at 6 % O 2 NO x with SNCR (no TWIN-NO x ) 250 mg/nm³ at 6 % O 2 NO x with SNCR (TWIN-NO x ) 200 mg/nm³ at 6 % O 2

15 Cooling of Flue Gases with Additional Water Variating the water quantity changes Droplet Spectrum Size of Droplets Penetration Depth Shift of area where reduction takes place by changing the concentration of water-reagent-mixture

16 Coal-Fired Boiler with and without Flue Gas Cooling Design Data Without Flue Gas Cooling With Flue Gas Cooling Fuel Lignite, light distillate Flue gas flow [Nm 3 /h] 173,000 NO x without SNCR [mg/nm 3 ] 400 NO x with SNCR [mg/nm 3 ] 200 NH 3 with SNCR [mg/nm³] < 15 Flue gas cooling starting at around 80% boiler load

17 Selective Flue Gas Cooling for Coal-Fired Boilers POWER-GEN Europe 2015

18 Selective Cooling for Coal-Fired Boiler Operating Results Design Data Flue gas flow max. Boiler load Nm³/h dry 85 t/h NO x without SNCR 400 mg/nm³ at 6 % O 2 NO x with SNCR 250 mg/nm³ at 6 % O 2 NO x with SNCR (with additional water) 160 mg/nm³ at 6 % O 2

19 Improved SNCR Performance through Flue Gas Cooling Increase of NO x reduction by adding cooling water

20 Features of Temperature Measurements in Two Levels t 1 > t 2 => V 1 < V 2 Temperature profiles without SNCR, with SNCR and with cooling water in two levels Flue gas velocities, directions and imbalances can be extrapolated. Areas which are too hot for SNCR can be identified to minimize cooling water. Adapting quantities of reagent and water results in lower loss of boiler efficiency, low ammonia slip, low NO X and better utilization of reagents.

21 Improved Precision in Measuring Flue Gas Velocities t 1 > t 2 => V 1 < V 2 Two levels of horizontal temperature measurement systems allow for measurement of several vertical temperature profiles Further improvements of overall SNCR performance by using NO x profiles generated with laser technologies.

22 SNCR for Rybnik Reagent Distribution based on Flue Gas Temperatures Acoustic Gas Temperature Measurement System (agam) provides - Flue gas temperatures without SNCR - Flue gas temperatures with SNCR - Flue gas temperatures with SNCR and selective cooling Temperature Information is used for - Injecting reagent in areas with optimum temperatures - Cooling flue gas in areas which are too hot for SNCR - Controlling process water to vary penetration and spraying pattern of reagent - Controlling of cooling water - Controlling of ammonia slip - Flue Gas velocities can be derived from temperature gradients Results - Higher efficiency (NO X - reduction) - Low ammonia slip - Less water consumption - Low consumption of reagent

23 Drax Power Station Different Configuration of Injection Systems POWER-GEN Europe 2015

24 SNCR Application for Coal-Fired Boilers OP 650 (225 MW el ) Rybnik Design Data Unit Rybnik Jaworzno Boiler capacity t/h NO X baseline mg/nm³ NO X emission limits mg/nm³ < 190 < 190 NH 3 slip mg/nm³ < 3,5 < 5 Ammonia in fly ash mg/kg < 100 ~ 50 agam level m Average temp. of flue gas C 1,300 1,350 Furnace cross section m m² 19 x x Boiler height m Boiler front wall to platen superheaters m Jaworzno

25 SNCR Application for Coal-Fired Boilers OP 650 (225 MW el ) Rybnik Jaworzno

26 Jaworzno III (225 MW el ) Control Display with Active Lances POWER-GEN Europe 2015

27 Jaworzno III (225 MW el ) Long Term Performance Data MW NO x NH 3 Load Guaranteed Average NO x Level NO x NO x Emission: 186 mg/nm³ (Average 6 Months) NH 3 NH 3 Slip in Fly Ash: 37 mg/kg (Average 6 Months)

28 Actual Status Jaworzno III, Poland Completed Commissioning Boiler Boiler Boiler Boiler Boiler Boiler Order Placed

29 SNCR for Coal-Fired Boiler - Jaworzno III (225 MW el ) Mixing and Metering Modules Injection Lances

30 References with SNCR for Coal-Fired Boilers Location Flue Gas [Nm³/h] dry NO x -Reduction [mg/nm³] (dry) NH 3 Slip [mg/nm³] Reagent Start Up Jülich, Germany 1 x 163, < 200 < 10 urea solution 2004 Völklingen, Germany 1 x 545, < 200 < 10 ammonia water 2010 Vřesová, Czech Rep. 5 x 390, < 200 < 20 ammonia water Jaworzno, Poland 6 x 685, < 190 < 10 urea solution Yunus Emre, Turkey 2 x 500, < 200 < 20 urea solution 2013 Deuben, Germany 5 x 153, < 180 < 5 urea solution Ostrava (Mittal Steel), Czech Republic 1 x 115,000 2 x 234, < 190 < 10 ammonia water Opatovice 4 x 277, < 200 < 10 urea solution Lodz, Poland 1 x 390, < 190 < 5 urea solution 2015 Rybnik, Poland 5 x 760, < 180 < 200 < 3,5 urea solution

31 Summary and Outlook SNCR technology complies with emission levels required by EU legislation in NO x levels < 200 mg/nm³ are achieved safely, even for large combustion plants > 200 MW el. TWIN-NO x and Selective Cooling have proven to be successful methods. Using SNCR technologies in combination with primary measures leaves room for further developments. SNCR technology aims now at boilers with capacities > 300 MW el.

32 POWER-GEN Europe 2014 POWER-GEN Europe 2015 Thank you for your Attention! Mehldau & Steinfath Umwelttechnik GmbH Alfredstr. 279, Essen Bernd von der Heide