catalytic pyrolysis of biomass/upgrading of bio- bed reactor [http ... gas heater pyrolysis ......

Download Catalytic pyrolysis of biomass/upgrading of bio-  bed reactor [http ... gas heater pyrolysis ... fluidization gas gases to coolers thermocouples in-pyrolysis reactor-up-grading reactor Thermal pyrolysis and

Post on 15-May-2018

214 views

Category:

Documents

2 download

Embed Size (px)

TRANSCRIPT

  • Catalytic pyrolysis of biomass/upgrading of bio-oil

  • PyrolysisPyrolysis

  • GasesVapours

    Pyrolysis

    Biomass

    CO, CO2,H2, HC

    Char

    Bio oil

    Upgradingover

    ZeolitesCondensationPyrolysis

    CarbonizationLow temperatureLong residence time

    Fast pyrolysisModerate temperatureShort residence time

    GasificationHigh temperatureLong residence time

  • Fast pyrolysis

    Moderate temperature400-500C

    High heating rateShort residence time

    1-2sRapid cooling

    Fluidized bed reactor

    [http://media3.washingtonpost.com/wp-srv/photo/gallery/090418/GAL-09Apr18-1902/media/PHO-09Apr18-158607.jpg]

  • Fast pyrolysisFast pyrolysis

  • Gas

    Char

    Char

    Water

    Bio-Oil

    Gas

    Bio- oil

  • Biomass

    PineCelluloseGalactoglucomannanSugar beet pulp

    [http://commons.wikimedia.org/wiki/File:SugarBeet.jpg][http://www.innventia.com/templates/STFIPage____6935.aspx][http://www.lifepinlaricio.org/pin-fi.htm]

  • Scaling -up

    Fluid Bed ReactorsGood temperature controlEasy scaling30 years of experience since first experiments at University of Waterloo in 1980sSmall particle sizes neededHeat transfer to bed at large scale has to be proven

  • Industrial installations

  • CFD

    Good temperature control in reactorLarger particle sizes possible,CFBs suitable for very large vthroughputs,

    Well understood technology,Hydrodynamics more complex,Char is more attrited due to higher

    velocities; separation is by cyclone,Heat transfer to bed at large scale has to be

    proven.

  • Bio-oil

  • Poor volatility, high viscosity, coking, corrosiveness, and cold flow problemsIn diesel engines: difficult ignition (due to low heating value and high water content), corrosiveness (acids), and coking (thermally unstable components). Bio-oil upgrading (catalytic) is needed

    hydrodeoxygenationzeolite upgrading via cracking

    Problems with bio-oilProblems with bio-oil

  • Bio-oil

    Complex mixture of organic molecules and waterAldehydes, acids, alcohols, ketones, phenols, polyaromatic hydrocarbons etc.

    More than 200 different compoundsThe chemical composition of the bio-oil is dependent on the raw material

  • Bio-oil

    Carbohydrates, cellulose and hemicellulose

    Furans, cyclopentanonesOpen chain acids, aldehydes, ketones and alcohols

    LigninAlkyl, methoxy, carbonyl and hydroxy substituted phenols

    OHO

    O

    5-(hydroxymethyl)furan-2-carbaldehyde

    CH3 O

    3-methylcyclopent-2-en-1-one

    CH3

    OOH

    1-hydroxypropan-2-one

    O

    OH

    CH3

    acetic acid

    OHO

    hydroxyacetaldehyde

    CH3O

    O

    OH4-hydroxy-3-methoxybenzaldehyde

  • Catalytic pyrolysis experiments

    Thermogravimetric analysis(TGA)Two fluidized bed reactors

    Zeolites as bed material providing heat and upgradingproductsSeparation of pyrolysis and catalytic upgrading

    Heat

    Fluidization gas

  • Preheating

    1

    2

    Ten-3-Gas

    VapourCondensation

    GasAnalyser

    Dual-fluidizedbed reactor

    BiomassFeeder

    Fluidization gasNitrogen 1.3L/min

    Biomass andgas feeding

    Nitrogen2L/min

  • Reactor set-up

  • Acidic zeolite catalystsCrystalline aluminosilicate minerals3-D microporous framework structureTetrahedrons of silicon (Si4+) and/or aluminium (Al3+) surrounded by four oxygen (O2-) anionsNeutral framework (silicon and oxygen)Negativelly charged framework (aluminium, silicon and oxygen)Framework balanced by a metal cation (Lewis acid) or a hydroxyl proton (Brnsted acid)

    Ferrierite

    Al-O

    +

    Si

    H

  • Determination of acidityPyridine is adsorbed to the zeolite sample

    FTIR is used to determine the acid sites

    Brnsted 1545 cm-1(hydron H+ donor)Lewis 1450 cm-1(electron acceptor)

    Quantitative amount of acid sitescalculated with the constants of Emeis

    [Emeis C.A., Journal of Catalysis 1993]

    Brnsted Lewis

  • TGA

    Polymers (LDPE)C-C bonds breaks at high temperaturesBrnsted acidity decreases the temperature needed for crackingEnergy saved

    BiomassDifferent zeolites testedNo difference in non-catalytic and catalytic thermograms

    [J. Agullo et al., Kinetics and Catalysis 2007][A. Aho et al., Catalysis in Industry 2008]

    zeolites thermal

  • Fluidized bed reactor

    Zeolites as heat carrierand catalysts in same reactorStudy the influence of acidity and structure of the zeolitesPine wood450C

  • Influence of structure and acidityZeolite structures

    ZSM-5, 3-D 10 ring 5.2 x 5.7 and 5.3 x 5.6 Intersection cavity: 9

    Beta, 3-D 12 ring 6.6 x 6.7 and 5.6 x 5.6

    Mordenite, 2-D 12 ring 7.0 x 6.5 and short 8-ring channels 3

    Y, 3-D 12 ring 7.4 x 7.4 and 11.8supercages

    Beta zeolites with different silica-alumina ratios (acidity)

    Y

    ZSM-5

    Mordenite

  • ResultsPyrolysis over zeolites compared to non-catalyticpyrolysis

    Decreased the bio-oil yieldIncreased the water yieldChanged the chemical compositionof the bio-oilAcidity influenced the formation of PAHsCoke was formed on the zeolites

    Possible to partly de-oxygenate the bio-oil over zeolite catalysts

    0

    2

    4

    6

    8

    10

    12

    Aldehydes Acids Alcohols Ketones Phenols PAHs

    yiel

    d w

    t-%

    H-Beta-25 H-Y-12 H-ZSM-5-23 H-MOR-20 Quartz

    [A. Aho et al., Fuel 2008][A. Aho et al., IChemE, part B, Process Safety and Environmental Protection 2007]

  • Dual-fluidized bed reactor

    Smaller amount of zeolites neededEasier to separate char and spent zeolitesSeparation of pyrolysis and catalysis reactorsImproved condensation

    Gas analysis

  • Zeolites as bed material providing heat and upgradingproductsSeparation of pyrolysis and catalytic upgrading

    Heat

    Fluidization gas

    Catalytic pyrolysisCatalytic pyrolysis

  • gas heater

    pyrolysisreactor biomass

    feeding

    catalyticup-grading

    inlet forfluidizationgas

    gases to coolers

    thermocouples in-pyrolysis reactor-up-grading reactor

    Thermal pyrolysis and catalytic upgradingThermal pyrolysis and catalytic upgrading

  • Dual-fluidized bed reactor

    Effect of binder (bentonite)Beta and ZSM-5

    Iron modification (ion-exchange)Beta, ferrierite and Y

    Reaction conditionsPyrolysis reactor 400CCatalytic upgrading reactor 450CPine

  • Zeolite characterizationIron content analysed by ICP-OESinductively coupled plasma - optical emission spectrometry

    Fe-H-FER-20 0.1 wt-%Fe-H-Beta-25 3.4 wt-%Fe-H-Y-12 5.4 wt-%

    The oxidation state and coordination of iron were investigated by ESRElectron spin resonance spectroscopy

    Structure and phase purity analysed by XRD

    0 10 20 30 40 50 60

    2

    Cou

    nts

    H-Y-12

    Fe-H-Y-12 fresh

    Fe-H-Y-12 reg

    Based on ESR the iron on Beta wasmostly tetrahedral Fe3+

    Iron modification and regeneration of the iron modified Y does not change thestructure nor the phase purity

  • Zeolite regenerationCoke was formed on the zeolites

    Regeneration by burning away the coke

    2h, 450C in air atmosphere

    Specific surface area

    0

    100

    200

    300

    400

    500

    600

    700

    H-Beta-25 Fe-H-Beta-25

    [m2 /g

    ]

    Iron modification increases the specificsurface areaThe spent zeolites has a fairly low areaPossible to regain the surface area through regeneration

  • Zeolite characterization

    H-Beta-25

    H-Beta-25

    H-Beta-25

    H-Beta-25

    H-Beta-25

    H-Beta-25

    Fe-H-Beta-25

    Fe-H-Beta-25

    Fe-H-Beta-25

    Fe-H-Beta-25

    Fe-H-Beta-25

    Fe-H-Beta-250

    20

    40

    60

    80

    100

    120

    140

    160

    weak medium strong weak medium strong

    Brnsted acid sites (mol/g) Lewis acid sites (mol/g)

    Iron modification changes the distribution of acid sites

    Most of the acid sites can be regained throughregeneration of the spent sample

    0

    20

    40

    60

    80

    100

    120

    140

    160

    weak medium strong weak medium strong

    Brnsted acid sites (mol/g) Lewis acid sites (mol/g)

    mol

    /g

  • Mass balance

    char

    oil

    watercokegas

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    non-catalytic H-Fer-20 Fe-H-Fer-20 H-Y-12 Fe-H-Y-12 H-Beta-25 Fe-H-Beta-25

    yield [%]

  • CO/CO2

    0.00

    0.25

    0.50

    0.75

    1.00

    non-catalytic H-Fer-20 Fe-H-Fer-20 H-Y-12 Fe-H-Y-12 H-Beta-25 Fe-H-Beta-25

  • Water yield

    0

    2

    4

    6

    8

    10

    12

    non-catalytic H-Fer-20 Fe-H-Fer-20 H-Y-12 Fe-H-Y-12 H-Beta-25 Fe-H-Beta-25

    yield [%]

  • Chemical compositionLevoglucosan transformed into

    Glycolaldehyde, formaldehyde, acetaldehyde, acetic acid and furfural

    Concentration of methoxy substituted phenols decreasedConcentration of methyl substituted phenols increased

    CH3

    OOH

    2-methoxyphenol

    CH3

    O

    CH3

    OH

    2-methoxy-4-methylphenol CH3OH

    2-methylphenol

    CH3

    OH3-methylphenol

    CH3

    OH4-methylphenol

    OOH

    CH3CH3

    2-methoxy-6-methylphenol

    OOH

    CH2

    CH3

    4-ethenyl-2-methoxyphenol

  • Conclusions: Bio-oil

    Many challenges including:Scale-upCost reductionBetter oil qualityNorms and standards for bio-oil

  • Conclusions: catalytic

    TGA not suitab

Recommended

View more >