Chemistry in Biomass Combustion
“ChemCom” 2005-2007
Åbo Akademi University (ÅA/PCC)
Helsinki University of Technology (TKK)
Tampere University of Technology (TUT)
Umeå University (UU)
Tekes
Andritz Oy
Foster Wheeler Energia Oy
International Paper Inc.
Metso Power Oy
Oy Metsä-Botnia Ab
Vattenfall Utveckling AB
IV Liekkipäivä, Tampere, January 2008
Project Objectives
• Produce detailed knowledge concerning chemical
phenomena that will influence on the biomass
combustion technology development
• The purpose is not to solve present acute problems,
but instead the topics are connected to long-term
questions
• The results are, as a principal rule, public, e.g. as
doctoral, licentiate and masters theses, journal
articles, etc.
Project Organisational Structure
Fundamental Research on
Chemistry in Biomass Combustion
Project
Co-ordination
(ÅA)
Project
Steering Group
Experiment
Modelling
Helsinki University
of Technology
Information
Tampere University
of Technology
Project Research Structure
15 workpackages
Biomass
Black Liquor
Waste
Experiment
E1
Modelling
Information
E2
M1
E3
E4
E5
E6
E7
E8
I1
I2
I3
I4
M2
M3
ChemCom Workpackages
E1. Experimental combustion facilities for fuel characterisation
E2. Experimental combustion analysis of black liquor
E3. Experimental combustion analysis of biomass
E4. Mineral Matter and Trace Elements in Biofuels
E5. Fundamental study of high temperature corrosion mechanisms in biomass
co-firing and black liquor combustion
E6. Fly Ash Behaviour of Fuel Mixtures
E7. Experimental black liquor spray characterisation (Järvinen, TKK)
E8. In-situ diagnositics of biofuel combustion chemistry (Hernberg, TUT)
M1. Application specific submodel development for CFD simulations (Järvinen, TKK)
M2. Collection and improvement of thermodynamic data for trace metal prediction in
combustion and gasification systems
M3. Kinetic simulations for studying gas-phase combustion chemistry in biomass
conversion systems
I1. Extension and utilisation of the ÅA fuel-, char- and ash databases
I2. Manganese (Mn) chemistry in biomass utilisation
I3. Analysis and evaluation of novel chemical recovery processes
I4. National and international collaboration
Development of a Laboratory Corrosion
Test Method and Evaluation of the Results
Part of workpackage E5
Corrosion Test Method
1. Preparation of salts – synthetic ash
• Chosen carefully – known melting behaviour
and composition
• Melted and grinded for homogeneity
• Analyzed to confirm the composition and
melt behaviour
Corrosion Test Method, cont.
2. Sample preparation for experiment
• Polish
• Oxidation
• Synthetic ash
2 cm
Before heat treatment
Corrosion Test Method, cont
3. Tube furnace test
Sample holder
Tube furnace
Corrosion Test Method, cont.
4. Sample preparation for SEM/EDX analysis
The alloy is then cast in epoxy, cut, polished and cleaned.
Corrosion Test Method, cont
5. Analysis of SEM results and determination of oxide layer thickness
140
120
100
80
60
40
20
Corrosion Test Results (1/2)
Oxide layer thickness, µm
140
120
100
Synthetic ash #1
T0 = 884oC
0% Cl
0% K
80
60
40
20
0
#1 2
l
ee el # #3
t
S
e
l
St tee el #4
#5 6
S
e
l
t
S
ee el #
t
S
e
St
60 o
575 o 0 C
550 o C
525 o C
500 o C
450 o C
C
Corrosion Test Results (2/2)
Oxide layer thickness, µm
140
120
100
Synthetic ash #6
T0 = 522oC
1.3% Cl
10% K
80
60
40
20
0
#1 2
l
ee e l # # 3
t
S
e
l
St tee el #4
#5 6
S
e
l
t
S
ee el #
t
S
e
St
600 o
575 o C
550 o C
525 o C
500 o C
450 o C
C
Ash Behaviour of Fuel Mixtures
Part of workpackage E6
•
•
Air-cooled probe deposits
and corrosion
Co-firing peat and wood
•
•
Superheater deposits
Co-firing coal and straw
60 min.
10 h
Ref.:F.Frandsen DTU
Why do the fuels interact?
ƒ
Mechanical reasons abrasion/erosion of deposits
with e.g. silica rich fuel ash
ƒ
Chemical reasons e.g. sulphation of alkali
chlorides (the troublemakers in combustion
systems => deposits, corrosion)
Deposition Rate
Interactions between Fuels
ion
t
c
ra
e
t
in
no
positive interaction
0
100% Fuel B
20
40
60
Fuel A (wt%)
80
100
0% Fuel B
Ref. M. Theis
Entrained Flow Reactor
- University of Toronto
Sample
feeder
Gas burner
Particles
9m
Furnace
Probe
Balance
VCR
Case: Co-firing Peat and Straw
- example taken from Mischa Theis´ Ph.D. Thesis, 2006
Peat ash (900oC)
20 µm
Straw ash (900oC)
Probe Surface after 40 min.
(Toronto, Canada)
100% Peat
40% Peat, 60% Straw
20% Peat, 80% Straw
100% Straw
Deposit Growth when Co-firing Peat and Straw
– Positive Interaction
160
2
Deposition (g/m h)
140
120
100
80
60
40
20
0
0
20
40
60
80
Straw fraction in feed (wt-%)
100
ÅA/PCC Personnel in ChemCom 2005-2007
Mikko Hupa
Åbo Akademi
Process Chemistry Centre
Patrik Yrjas (from Aug. 2006)
Christian Mueller (until Aug. 2006)
Bengt-Johan Skrifvars
Rainer Backman
Anders Brink
Mikael Forssén
Jukka Konttinen
Maria Zevenhoven
Edgardo Coda Zabetta
Daniel Lindberg (diss. 2007)
Mischa Theis (diss. 2006)
Vesna Barisic (diss. 2007)
Johan Werkelin
Markus Engblom
Dorota Bankiewicz
Patrycja Derda
Micaela Westén-Karlsson
Tarja Talonen
Tor Laurén
Johan Lindholm
Combustion and Materials Chemistry
Prof. Mikko Hupa
Chemistry
Ida Combustion
Mann
Kjell Strandström
Bingzhi Li
Chemistry
HaoMaterials
Wu
Marco Grava
Oskar Karlström
Peter Backman
Luis Bezerra
Piia Leppäsalo
Jaana Paananen
Linus Silvander
Mia Mäkinen
Eva Harjunkoski
+ a number of visiting scientists and students