Chemistry in Combustion Processes I
Introduction
Åbo Akademi University
Chemical Engineering
Laboratory of Inorganic Chemistry
Energy in Finland: 80 % Combustion
Import of Power
Others
Peat
Wood Fuels
Hydro
Nuclear
Natural Gas
Coal
Oil
Finland
• Leading in the use of bioenergy
• Leading in combustion engineering:
- biofuels: fluidised beds
- pulping spent liquor (black liquor) combustion
- large Diesel engines
• Extensive research and development activities
Alholmen Power Plant
ALHOLMEN FLUIDISED BED BOILER 550 MW (545 °C) Peat, Bark, REF, Forest Residue, Sawdust, Coal, Oil Boiler Efficiency 92 % SO2 100 mg/MJ NOx 50 mg/MJ Particulate 30 mg/m3n
Kvaerner Power Oy - 2001
Capacity of FBC Boilers World-wide 2003
0
10
20
30
40
50
60
70
1975 1980 1985 1990 1995 2000
Year
Cu
mu
lati
ve c
ap
acit
y [
1000 M
Wth
]
CFBC
BFBC
PFBC
FBG
Use of
Wood in
Finland
(VTT 2000)
Use of
Wood in
Finland
(VTT 2000)
Black Liquor – An Energy Rich
Byproduct at Pulp Mills
Tomlinson Boiler, 1937 Wisaforest, 2004
85 m
15 m
Fray Bentos, Uruguay (Andritz)
Hainan Jinhai, China (Valmet 2007)
Black Liquor Recovery Boilers 1937-
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Delivery year
Ca
pa
city, t D
S/d Daily Capacity
ton Dry Solids
Research in combustion engineering
• Environmental challenges
• Efficiency
• ”New” fuels: biofuels, waste derived fuels,
fuel mixtures
• Fundamental understanding of the processes
• More chemistry
100 %
100 ppm
1 %
1 ppm
1 ppb
(µg/kg)
1 ng/kg
1 pg/kg -15
CO2 Carbon Dioxide
CO Carbon Monoxide / CxHy Hydrocarbons
PAH Polyaromatic Hydrocarbons
As, Cr, Ni, V, Pb, Cd, Hg,... Heavy Metals
Dioxins, Furans
SO2 Sulfur Dioxide / NOx Nitrgen Oxides
-5
-10
0
Environmental challenges - Flue Gas Emission Components
Research in combustion engineering
• Environmental challenges
• Efficiency
• ”New” fuels: biofuels, waste derived fuels,
fuel mixtures
• Fundamental understanding of the processes
• More chemistry
Biofuels – Waste derived fuels – “Opportunity fuels”
Forest residues Annual crops
Prunings Shells, husks & hulls
Olive stones RDF (refuse derived fuels)
Waste sludges MBM (meat and bone meal)
Chicken litter Coal Slurry Pet coke
Åbo Akademi Fuel Data Bank
This Course Introduces...
• Industrial-scale combustion systems
• Chemistry of emission components
• A ”Process Chemistry Toolbox” for theoretical
analysis of combustion processes