air pollution & modern boilers€¦ · boilers (going back to the 1970ies in austria)...

Air pollution & modern boilers Christoph Schmidl Senior Researcher at Bioenergy2020+ and Austrian Team Leader in IEA Bioenergy Task 32 (Combustion and Cofiring)

Vienna, 24 April 2018

Biomass burning is a major source of air pollution

Vienna, 24 April 2018 Slide 2

Setting the scene: Energy and air pollution


How come? Emissions from biomass burning – quite a complex topic


Health impact: The type of aerosol makes the difference…

Kippel & Nussbaumer, European Biomass Conference, 2007. Berlin

■ Biomass Combustion Technology has improved tremendously:

■ FJ-BLT Wieselburg Type Testing Averages 2015/16 (n=26): ■ Efficiency = 96% ■ Carbon Monoxide = 5mg/MJ ■ Organic gaseous Carbon < 1mg/MJ ■ Total suspended Particles = 7mg/MJ

■ Further Improvement Potential? ■ No, or very limited ■ Already complete Combustion

■ EN303-5 testing at constant Load Conditions


Modern biomass boilers

Slide 6

■ Standardisation: ■ Standardised testing of biomass

boilers (going back to the 1970ies in Austria)

■ European/international standardisation (e.g. EN303-5) ■ Regulatory framework:

■ Performance requirements for market implementation – Referring to standardised evaluation procedures – Based on state-of-the-art of technology

■ Ambitious but also reasonable (plannable) EU Ecodesign ■ Big efforts in technology development

■ e.g advanced control concepts (Lambda probe, model based control)


Keys to this success


Also a success for air quality

Emissions in 1000 tons Installed capacity in MW

Nominal capacity biomass boilers

Particle emissions small-scale (PM10)

Particle emissions small-scale (PM2.5)

Sources:

Source Figure: Austrian Biomass Association

0102030405060708090

100

Avg. 78,0 [%]

efficiency

■ Real-life (field) emission factors of pellet boiler in modulating operation:

■ Variable performance (extremely good – medium)

Everything fine? Let us look into field performance…


0

200

400

600

800

1000

1200

1400

Avg. 417,7 [mg/m³ (STP)]

CO

0

50

100

150

200

250

Avg. 138,8 [mg/m³ (STP)]

NOx

0102030405060708090

100

Avg. 10,0 [mg/m³ (STP)]

OGC

0102030405060708090

100

Avg. 26,2 [mg/m³ (STP)]

TSP

* Data from BioMaxEff project Slide 9

0

100

200

300

400

500

600

700

800

900

ConventionalStoves

EfficientStoves

Advancedstoves/boilers

Small-scaleeasternEurope

Small-scalewesternEurope

Small-scaleresidential

2010

Small-scaleresidential

2030

FirewoodStoves

Pellet Stoves

EU EMEP Guidebook 2016 (Tier 2) IIASA, RAINS database German Ministry forEnvironment 2010

beReal Project 2016

TSP

Emis

sion

Fac

tor [

g/G

J]

Wieselburg, 25.4.2018

TSP (Dust): Emission Factor Comparison

Range of emissions is huge (2 orders of magnitude)

Emissions Biomass

Combustion

Combstion-technology

Fuel Quality User /

Installation Influence


The three main influencing factors for real-life performance of biomass boilers…

e.g. Combustion chamber design Combustion air settings Flue gas sensors (Lambda) Control concept (combustion control and load management

e.g. Natural wood / wastes Water / ash content

e.g. Correct sizing of boiler / stove Hydraulic integration in building/process Heat distribution concept and control User habits incl. maloperation

■ Intelligent Control Algorithms: ■ E.g. Model based Control Concepts (incl. weather

prediction and self-learning systems) ■ New combustion concepts

■ Extreme air staging (for boilers) ■ Candle burning principle (for stoves)

■ Integration of secondary emission abatement systems (e.g. Electrostatic precipitators or catalysts)

■ Real life optimisation and testing methods

Further improvement (of real life performance) is ongoing…

Folie 12 Vienna, 24 April 2018

■ Testing methods strongly influence technological development

■ Real-life oriented testing methods can support / force development into the right direction

■ Proposals for such methods are available: ■ Load Cycle Testing of

Boilers (www.biomaxeff.eu) ■ beReal Tests for Stoves

(www.bereal-project.eu)


Real-life oriented testing methods circulation on

pump off

exhaust onfan off

boiler onoff

reference cycle flow temperature / TVL return temperature / TRL

45°C

55°C

75°C

55°C

45°C

15

30

45

60

75

90

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

tem

pera

ture

[°C]

nom

inal

boile

r loa

d [%

]

time

8h

t1 t2t0 t3 t4 t5

8h

measurements

1. Modern biomass combustion technology has reached a very high level of performance under standardised testing conditions (~ complete combustion in boilers).

2. Further sharpening of already very low emission thresholds (in regulations or quality labels) will mainly increase the turnover of testing labs (for re-testing) but will not improve the performance in real life.

3. The keys to better air quality are a) Replacement of old appliances (factor: 10 – 100(0)) b) Focus on real-life performance (supported by

suitable testing methods) Vienna, 24 April 2018

Key Messages 1

Slide 14

4. Innovative solutions for further improvement of the performance of biomass appliances in the field are… a) Advanced control strategies such as model based

control systems for combustion- and load-control (reducing starts and stops)

b) New combustion concepts implementing advanced primary measures for emission reduction (e.g. extreme air staging, candle burning principle)

c) Secondary emission abatement technologies for bigger size boilers (~ > 100kW)


Key Messages 2

Slide 15

■ Q1/Technology: Which measures can support market penetration of state-of-the-art technology? What are the biggest barriers for these technologies (e.g. costs)?

■ Q2/Fuel: How can we ensure that only suitable fuels are used?

■ Q3/User and Installation: Which measures can ensure proper installation and operation of combustion appliances?


Questions

[email protected]

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