Rapporto aria Combustibile

download Rapporto aria Combustibile

of 18

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