Emissions from Biomass Boilers - The State of the Art · Austrian Centre of Competence in Biomass to Energy Manuel Schwabl [email protected] Biomass & Air Quality

BIOENERGY 2020+ Austrian Centre of Competence in Biomass to Energy

Manuel Schwabl [email protected]

Biomass & Air Quality

10. October 2017, Piacenza, ITALY

mailto:[email protected]


Wieselburg

Güssing

Graz

BE2020 locations

Piacenza, 10. October 2017

Areas of competence


Combustion Gasification Bioconversion

B I O M A S S utilisation

Areas of competence



• Advanced application oriented characterisation

methods for fuels

• Biomass for residential and tertiary applications

• Marketable micro- und small-scale CHP plants

• Biomass for medium and large scale applications

• Emission characterisation & emission reduction

Areas of competence



• Increase of resource

basis including

biogenous residues

• Biomass for industrial

applications, e.g.

substitution of natural

gas

• Syngas-platform for

bio-refineries

• Plants with poly-

generation (heat,

electricity, fuel)

• Hybrid systems with

other RE

Areas of competence



• Bioconversion to gaseous and liquid biofuels

• Pre-treatment technologies to enhance biogas

yield

• Nutrient recovery and recycling

• H2 utilisation and biogas up-grading

• Cascadic use of biomass

Areas of competence – cross cutting topics


emission reduction by model based control

CO

em

issio

ns

Sustainable supply

and value chains

Automation & control

Modelling & simulation

Close contact to industry


… a n d m a n y m o r e …

Academic work in numbers - 2017


9 Master Thesis

6 Bachelor Thesis

>15 PhD Thesis

More than 30 journal papers

More than 40 conference papers

Interested in internship/thesis writing?

Partner in ERASMUS+ programme and eligible for „thesis abroad“ program of PoliMi

State of the art of residential small scale combustion appliances and innovative products Manuel Schwabl [email protected]




Overview

What is emitted by biomass boilers

The evolution of emissions

Technology impressions

Upcoming Challenges

Innovation examples


Emissions from biomass boilers E

mis

sio

ns fro

m

inc

om

ple

te c

om

bu

stio

n

• Carbon monoxide (CO)

• Volatile organic compounds

(VOC): e.g. Methane,

Polyaromatic hydrocarbons (PAH),

• Particulate matter (PM): soot and

other organic particulates

Em

issio

ns d

urin

g

co

mp

lete

co

mb

ustio

n

• Carbon dioxide (CO2)

• Nitrogen oxides (NOx)

• Sulphur oxides (SOx)

• Chlorine Acid (HCl)

• Particulate matter (PM): Inorganic

aerosols and coarse particles


Combustion Technology Fuel properties

Emission formation Emission from Incomplete combustion


Time

Temperature

Turbulence

- Streak formation

- Availability of oxygen

- Air excess ratio

- Air excess ratio

- Dimensioning of

combustion chamber

- Air excess ratio

- Lining of combustion

chamber

- Cold surface


Piacenza, 10. October 2017 Kaltschmitt M., Hartmann H., et al.; Energie aus Biomasse, 2009, SpringerLink


Secondary & tertiary reactions during combustion

Piacenza, 10. October 2017 Evans, Robert J., und Thomas A. Milne. „Molecular characterization of the pyrolysis of

biomass“. Energy & Fuels 1, Nr. 2 (1987): 123–137.

Emission formation Emission during complete combustion

NOx emission

Piacenza, 10. October 2017 Kaltschmitt M., Hartmann H., et al.; Energie aus Biomasse, 2009, SpringerLink

Emission formation Emission during complete combustion

SOx, HCl and PM emission


Bottom ash

Condensation on coarse

fly ash particles

Coarse fly ash particles

entrained from the fuel bed

K, Na, S, Cl, easily

volatile heavy metals

released from the fuel

to the gas phase

Gas phase reactions

Cooling phase

Nucleation

Condensation

Coagulation

The evolution of emissions





The evolution of emissions Carbon Monoxide


CO

[mg/m3]

0

excess air ratio

10

100

1000

10,000

100,000

1 2 3 4 5

a

b

d

c

a) simple, manually charged

wood boiler;

b) downdraught wood log boiler;

c) automatic furnace with

combustion technology as of

1990

d) automatic furnace with

enhanced combustion

technology as of 1995.

Automatic furnaces with

appropriate combustion process

control can be operated under

optimum conditions.

The evolution of emissions Carbon Monoxide


0

5,000

10,000

15,000

20,000

25,000

1980 1985 1990 1996 2001 2007 2012

CO

[m

g/M

J]

source: FJ BLT Wieselburg; compiled: Bioenergy2020+

The evolution of emissions energy efficiency


40

50

60

70

80

90

100

1980 1985 1990 1996 2001 2007 2012

eff

icie

nc

y [

%]

source: FJ BLT Wieselburg; compiled: Bioenergy2020+

The evolution of emissions Total Organic Hydrocarbons


0

5

10

15

20

25

110 113 30

1999 - 2004 2005 - 2009 2010 - 2014

VO

C [

mg

/MJ

]

minimum average median maximum

source: FJ BLT Wieselburg; compiled: Bioenergy2020+ GmbH

quantity

period

The evolution of emissions Nitric Oxides emission


0

20

40

60

80

100

120

140

160

110 113 30

1999 - 2004 2005 - 2009 2010 - 2014

NO

x [

mg

/MJ]



quantity

period

The evolution of emissions Particulate Matter emissions


0

5

10

15

20

25

30

35

110 113 30

1999 - 2004 2005 - 2009 2010 - 2014

PM

[m

g/M

J]



quantity

period

The evolution of emissions Benzene(a)pyren Real-life Emissions

■ Best-case scenario


Best Case Worst Case Moderne „traditional“

Automatically fed biomass

combustion

Firewood single room heaters

1x Start und Stop,

8 h full load

Abwechselnder

Start&Stop-Betrieb

Primär & Sekundärluft Kelz et al. 2012,

Ozgen et al. 2014

Kelz et al. 2012

Orasche et al. 2012

Technology Impressions





Log wood boiler

source: www.sht.at, www.ligno.at,


http://www.sht.at/

http://www.ligno.at/

Wood chip boiler

source: www.kwb.at; www.hdg-bavaria.com


HDG

http://www.kwb.at/

http://www.hdg-bavaria.de/



Pellet boiler technology


source: www.windhager.at, www.hargassner.at, www.eta.co.at, www.pelletsheizung.at

http://www.windhager.at/

http://www.hargassner.at/

http://www.eta.co.at/

http://www.pelletsheizung.at/

Multi fuel burner

Crawler burner Auger type burner


source: www.kwb.at, Ligno Heizsysteme GmbH

http://www.kwb.at/

Key Technologies for emission evolution

Downdraft boilers concerning log wood systems

Induced draught

Combustion chamber with lining

Air excess control system

• By lambda probe or CO sensor

• Modulation of fuel mass flow or air suppy mass flow

Staged combustion

• Air excess ratio in bed 0.7-0.9

Load modulation of combustion system

Flue gas recirculation (for appliances > 100kW)


Top 25% products


0

50

100

150

< 25 kW 25 - 35 kW 35 - 50 kW 50 - 100 kW >100 kW

CO

[m

g/M

J]

Log wood Wood chips Pellets

0

10

20

30

40

< 25 kW 25 - 35 kW 35 - 50 kW 50 - 100 kW >100 kW

PM

[m

g/M

J]

Log wood Wood chips Pellets

Musil-Schläffer B., McCarry A., Schmidl C., Haslinger, W. European Wood-Heating

Technology Survey. Final Report 10-01. APRIL 2010, prepared for New York State Energy

Research and Development Authority

http://www.nyserda.ny.gov/Publications/Research-and-Development-Technical-Reports/Other-

Technical-Reports/European-Wood-Heating-Technology-Survey.aspx

http://www.nyserda.ny.gov/Publications/Research-and-Development-Technical-Reports/Other-Technical-Reports/European-Wood-Heating-Technology-Survey.aspx






















Secondary emission abatement measures

■ Oxy-catalyst

■ PM separation systems

■ Electrostatic precipitators

■ Baghouse filters

■ Cyclones

■ Condensing heat exchanger

■ Scrubber systems

■ Catalytic or non-catalytic DeNOx


Köb Viessmann Group

Clariant

Zumikon by Ruegg Oekosolve

Upcoming Challenges





Real-life emission

Boiler sizing

Energy dissipation system

Building control system

Weather

Fuel

Consumer


Frequency of start & stops

Full load hours

Necessity to modulate power output

Probability of instable conditions

Pushing the boundaries – R&D tasks being tackled

Technology progress

• Differences between type tested systems and series products

• System – Thinking. Integration of the whole heat dissipation system

when assessing real-life emissions.

• Extreme air staging. Challenging in residential combustion appliances:

instabil fuel bed, increased risk of corrosion is possible

• Secondary measures. Challenging in residential application, question

of economics. Downscale and development process still ongoing

• Model based control of load and combustion (e.g. incl. weather

forecast)

• Bidirectional heat grids (Prosumers)


Pushing the boundaries – R&D task being tackled

Fuel influence

• Aerosol forming elements (chlorine, sulphur, potassium, sodium,

zinc,…), nitrogen content

• High quality „Design“ fuel – but where remains the fuel flexibility?

• DeNOx to increase the fuel range also in small scale

• Fuel applicability testing necessary in particular for series products


Innovation





Sustainable developments

Wood briquette candle

burner

• variable and low heat output

(1.8-4 kW)

• constant combustion conditions

and low emission release

• maximal comfort for end-user (especially for low-energy and passive houses)

Tradition meets Hightech

Tiled stove & heat pump

• Dissipation of tiled stove heat to house

heating system

• Variable operation of heat pump (outdoor air or

heat from hypocaustic space of tiled stove)

• Maximizing energy efficiency

Ho

use s

yste

m

Am

bie

nt

air

or

tile

d s

tov

e

Combustion chamber

Combustion chamber is divided in two parts by

a ring, where secondary air is supplied

■ High temperature in CC1 (primary

combustion)

■ Secondary air provided at teh ring

■ Long residence time in the second

combustion chamber CC2

SA SA

PA PA CC1

CC2

Bottom

PA

SA

Ring for

secondary air

supply

Prototyping: Feeding process:

Grate (platform) for

briquette

Briquette insertion

through combustion

chamber

Briquette cranked at

ignition position

Prototyping

■ Combustion chamber:

Insulated cavity for

secondary air

Insulated cavity for

primary air

Combustion

chamber

Grate for

briquette

Primary air

Secondary air

Secondary air

ring and

partition of

combustion

chamber into

two parts

Prototyping: ingition

Applied square timber

(~200g) with firelighter Ignition by hand

Fast initial combustion:

• Fast glowbed buildup

Start of

feed motion

(11,9cm/h~4,3kW)

■ Results with the first prototype:

Results and Highlights

6h burning period

CO PM NOx orgC Eff.

Full load [mg/Nm3/13%O2]

120 30 220 1,8 85

% Full load [mg/MJ]

88 21 150 1,2

Part load [mg/Nm3/13%O2]

223 27 250 3,5 84

% Part load [mg/MJ]

150 18 170 2,5

Low heat output <3 kW possible

Variable output regulation

Combustion periods up to 8 h are feasible

Combination of advantages of pellet and log

wood stoves (natural draught, costs)

Tests with several briquetts from EU market

Tests of misuse behavior

Austroflamm Mr. Wu available in autumn 2017

www.austroflamm.at

Market introduction

http://www.austroflamm.at/

Thank you very much for your attention

Manuel Schwabl Head of Unit Emission Technology & Research, Direct Heating Systems Area Combustion [email protected] Tel: +43 7416 52238 41

BIOENERGY2020+ GmbH

Location Wieselburg



Documents

Emissions from Biomass Boilers - The State of the Art · Austrian Centre of Competence in Biomass to Energy Manuel Schwabl [email protected] Biomass & Air Quality