Rapporto aria Combustibile
-
Upload
marco-macci -
Category
Documents
-
view
215 -
download
0
Transcript of Rapporto aria Combustibile
-
7/21/2019 Rapporto aria Combustibile
1/18
The Science of BiomassStoves
Thomas ReedThe Biomass Energy Foundation
Golden, Colorado
Presented at ETHOSSeattle, WA
January 30, 2005
-
7/21/2019 Rapporto aria Combustibile
2/18
The Biomass Energy Foundation 2
THE SCIENCE AND ART OF
COOKING Cooking is more complex than nuclear science
Nuclear science complete in 100 years Cooking was an art for 100,000 years Great progress in last 100 years mostly in new fuels
and electricity, unavailable in much of the world
Cooking improvements have been science based Not all cooks are science based Stove designers should be science based
Biomass Cooking Science based on FUEL PYROLYSIS to 400 C GASIFICATION to 1000 C COMBUSTION to 2000 C
P-G-C understanding needed for designing stoves!
-
7/21/2019 Rapporto aria Combustibile
3/18
The Biomass Energy Foundation 3
FUELS
Energy source Fuel
Energy sources: Solar, wind, PV, geothermalmust be used as they occur
Fuels provide chemical storage of energy Always available
Easy to convert to high temperature, electric
power
-
7/21/2019 Rapporto aria Combustibile
4/18
The Biomass Energy Foundation 4
CO2
CO0.2 0.4 0.6 0.8
H
C O
H2O
While fuels canhave many othercomponents,carbon (C),hydrogen (H)and oxygen (O)are the principlefuel elements.
The location ofany compoundcan be plottedon a triangulargraph showingthe relativeamounts ofeach element.
Water: Two Hand 1 O, solocated at .33 O,.66 H
Carbon Monoxide isan excellent fuel gas
Hydrogen, H2 is aunique fuel gas
UNIVERSAL FUEL MAP
-
7/21/2019 Rapporto aria Combustibile
5/18
The Biomass Energy Foundation 5
SIMPLIFIED FUEL FORMULAS
H
C O
H2O
CO2CO
CH4
Coal
CH
HydrocarbonsCH2
Biomass
Synthesis Gas orProducer gas withvariable H2/COratio
H2The large areasindicate ranges ofcomposition
Charcoals
0.2 0.4 0.6 0.8
-
7/21/2019 Rapporto aria Combustibile
6/18
The Biomass Energy Foundation 6
BIOMASS CONVERSION ROUTES
0.2 0.4 0.6 0.8
H
C O
H2O
CO2CO
H2
Biomass
LEAN COMBUSTION
GASIFICATION:
CH1.4O0.6 + .25 O2 CO + .7H2
Charcoals
Pyrolysis:
BiomassCharcoal + water+ tars
COMBUSTION to CO2and 0.7 H2O
-
7/21/2019 Rapporto aria Combustibile
7/18
The Biomass Energy Foundation 7
ATOM ENERGIES
0.2 0.4 0.6 0.8
H
C O
H2O = 0
CO2 =0CO = 142
H2 = 143
Methane = 176
Coal
HydroCarbons =219
Biomass =162
CarboHydrates = 122
Synthesis gas = 142
394
269
This map shows how the heatof combustion per atomdecreases as you move up andto the right on the chart.
-
7/21/2019 Rapporto aria Combustibile
8/18
The Biomass Energy Foundation 8
COMBUSTION
Combustion is the complete conversion of
the chemical energy in a fuel to heat formaking heat or power
Air is the principle ingredient for combustion,but unknown to the public - they focus onfuels and $$
1 kg gasoline + 15 kg air completecombustion
-
7/21/2019 Rapporto aria Combustibile
9/18
The Biomass Energy Foundation 9
IMPORTANCE OF THE
AIR/FUEL RATIO The air/fuel ratio determines
Pyrolysis
Gasification
Clean combustion Efficient combustion
Lean combustion
Rich combustion
AND THEIR OPPOSITES
-
7/21/2019 Rapporto aria Combustibile
10/18
The Biomass Energy Foundation 10
THE A/F EQUIVALENCE RATIO
The A/F ratio for combustion is different forevery fuel
Gasoline 14.7 kg air/kg fuel
Ethanol 9 kg air/kg fuel
Biomass 6 kg air/kg fuel Hydrogen 40 kg air/kg fuel
The equivalence ratio is the same for all fuels
for combustion, gasification and pyrolysis
ER= (A/F)/(A/F)complete combustion
-
7/21/2019 Rapporto aria Combustibile
11/18
The Biomass Energy Foundation 11
0.2 0.60.4 0.8
1,000
1.00
BIOMASS P-G-C DETERMINED BY EQUIVALENCE RATIO
Pyrolysis
Combustion
Rich Lean
A/F = ~6for biomass combustion
A/F = ~1.5
Biomass gasification
Temperature-C
FlamingPyrolysis
2,000
0
EQUIVALENCE RATIO
-
7/21/2019 Rapporto aria Combustibile
12/18
The Biomass Energy Foundation 12
PYROLYSIS Pyrolysis is the breakdown of biomass by
heat to form
Gases volatile liquids
and charcoal, all good fuels
Pure pyrolysis requires an external heatsource and heat exchange
Flaming pyrolysis burns a small amount ofthe volatiles to generate the heat for pyrolysisin beds of fuel or a match
-
7/21/2019 Rapporto aria Combustibile
13/18
The Biomass Energy Foundation 13
GASIFICATION Gasification of biomass produces a gas
Gases are required For cleaner heat in
In engines, turbines, fuel cells,
For synthesis of fuels and chemicals (NH3,..)
Coal gasification was universal from 1850-
1930 when natural gas pipelines weredeveloped
-
7/21/2019 Rapporto aria Combustibile
14/18
The Biomass Energy Foundation 14
C-G-P OCCUR IN THE BURNING MATCH
Combustion
Gasification
Pyrolysis
Charcoal
-
7/21/2019 Rapporto aria Combustibile
15/18
The Biomass Energy Foundation 15
APPLICATION TO STOVE
DESIGN Consider that each kG of wood can generate
20 MJ of heat It takes 6 kg of air to burn each kg of wood
Wood burns in two stages initially thevolatiles burn, then the charcoal
Wood is difficult to burn cleanly because it
cant be mixed with air
-
7/21/2019 Rapporto aria Combustibile
16/18
The Biomass Energy Foundation 16
APPLICATION TO WOODSTOVE
DESIGN It takes ~1/2 to 1 1/2 kg of air to make 2
kg of WoodGas It takes 5 kg of air to burn each kg of
WoodGas WoodGas burns much cleaner than
wood because it can be mixed withoptimum air
-
7/21/2019 Rapporto aria Combustibile
17/18
The Biomass Energy Foundation 17
The WoodGas Cookstove
-
7/21/2019 Rapporto aria Combustibile
18/18
The Biomass Energy Foundation 18
OTHER APPLICATIONS OF
BIOMASS PGCPower generation from
biomass
Liquid fuels from biomassHome heating
Industrial heatingGO FOR IT! Thank you