Thermochemical Conversion of Biomass - PDF by xld14276

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									Biomass fast pyrolysis
  biorefinery opportunities
        and catalysis

       Wolter Prins

     RRB5, Ghent, 10th June 2009




                                   1
1                               Contents


    1.   Thermochemical conversion of biomass
    2.   Fast pyrolysis, oil properties and applications
    3.   Fast pyrolysis biorefinery opportunities
    4.   Catalysis in fast pyrolysis
    5.   Conclusions




                                                           2
1                   CO2 + H2O +                        CH2O + O2

    lignocellulose is the main part of
    biomass: carbohydrates and lignin     CH1,4O0,66   C (wt.%)    O (wt.%)    H (wt.%)
                                             total        50        40 - 43      5-8
    extractives, proteins and minerals
                                            carbo-
    are present in smaller amounts                      44 - 45     48 - 49      6-8
                                           hydrates
    much oxygen in carbohydrates,            lignin       64          30          6
    significantly less in lignin

               biomass residues like wheat straw, corn stover or sugar cane bagasse
               contain much ash and N, S, Cl




                                                                                          3
1                         Thermochemical processes

    combustion                      heat
    gasification                                 gas
                                    combustible waste
                                          wood /

    slow pyrolysis                  charcoal
                                                         gas
    torrefaction                    partially carbonized biomass
    fast pyrolysis                  pyrolysis oil, bio-oil
    hydrothermal liquefaction       biocrude
    hydrothermal carbonization      biochar
    gasification in                 pressurized combustible gas
    supercritical water

                                                                   4
1                Product routes (simplified)

                 combustion     heat                 heat

                                                             CHP
    thermal      gasification   fuel gas / syngas

                                                     electricity
                 pyrolysis      bio-oil


    biological   fermentation   bioethanol           chemicals


                 digestion      biogas
                                                    transport fuels
    mechanical                  plant oil
2                                 Fast Pyrolysis

    Random chemical degradation
    due to rapid heating in absence
                                                       ste
    of oxygen                                wood / wa
                                                    prim. electricity
    Process characteristics
                                                               gas
                        500       oC
      temperature
      pressure          1         atm
      particle size     <5        mm
      τ vapors          <2        sec


    Products
      bio-oil           70        wt.%
      permanent gas     10 - 15
      char              10 - 15


                                                                        6
7
2   BTG Malaysia plant (2 ton/hr)


                                  ste
                        wood / wa
                               prim. electricity

                                          gas




          empty fruit
           bunches



                                                   8
2                                  BTG-BTL Hengelo plant (5 ton/hr)



                                                                25 MWth       Process Steam


                                                                Poly-
                                                                Generation     Electricity
                                           120 t/d waste wood
                                                                Pyrolysis
                                                                              Stabilized Fuel Oil
The production of electricity, heat, and
fuel oil can be adjusted to the actual
                                                                Plant
demand of the specific location                                              Organic Acids



            Gerhard Muggen, 2009
                                                                                                    9
2                                   Bio-oil properties
                                                                   BTG
                          bio-oil   heavy fuel oil                 Netherlands



    vol. energy density    21            39          GJ/m3
    density               1220          963          kg/m3
    viscosity at 50 oC     13           351          mm2/s   gas
    acidity                 3            7           pH
    water content          20            0.1         wt.%
                                                                   VTT,
    ash content           0.02          0.03         wt.%          Finland

      C                    52            86          wt.%
      H                     7            10          wt.%
      O                    40           0.5          wt.%
      N                    0.1          0.6          wt.%
      S                   < 0.1           2          wt.%

                                                                                 10
1                                                   lignocellulose
polymer of mostly glucose units (up to 8000)
chains are linked by hydrogen bonds          cellulose
if crystalline, insoluble in most solvents
40 to 50 % of the cell wall matrix
polymer of C6 and C5 units(xylose, arabinose) up to 200
amorphous, with acetyl groups
                                        hemicellulose
easy to hydrolyze
25 to 35 % of the cell wall matrix

hemicellulose and lignin form a sheath around the
cellulosic part of the biomass


20 to 30 % of the wood matrix
3-dimensional aromatic
structure of phenylpropane units                          lignin

                                                                     11
2              Reported maximal(!) yields of chemicals in bio-oil

levoglucosan                      30.4   wt%   formaldehyde                  2.4
hydroxyacetaldehyde               15.4         phenol        ste
                                                                             2.1
                                                   wood / wa
acetic acid                       10.1         propionic acid. electricity
                                                          prim               2.0
formic acid                       9.1          acetone               gas
                                                                             2.0
acetaldehyde                      8.5          methylcyclopentene-ol-one     1.9
furfuryl alcohol                  5.2          methyl formate                1.9
catechol                          5.0          hydroquinone                  1.9
methyl glyoxal                    4.0          acetol                        1.7
ethanol                           3.6          angelica lactone              1.6
cellobiosan                       3.2          syringaldehyde                1.5
1,6-anhydroglucofuranose          3.1          methanol                      1.4


          Tony Bridgwater, 2006
                                                                                   12
   2                            Possible applications of fast pyrolysis oil
                                                                   Bio-oil


                                         thermal                                                      ste             chemical
                                                                                            wood / wa


    upgrading                 gasifier                 boiler                micro turbine              fractions                compounds
                                                                                                             gas
                                                   co-combustion             diesel engine


 refinery co-feed             syngas                    heat                    power                 liquid smoke                 aldehydes
                             hydrogen                  steam                  electricity               adhesives                   phenols
                                                     electricty                  heat                    fertilizer              levoglucosan


transportation fuels   transportation fuels
     chemicals              chemicals




                Dietrich Meier, 2008
                                                                                                                                             13
 3                                Biorefinery opportunities

Biorefinery :        cluster of biobased industries producing chemicals, fuels, power, products, and
                     materials (Iowa State University)



Fast pyrolysis may be the basis of a stand-alone biorefinery or could be
integrated
           with bio-ethanol production               corn stover, corn fibres, wheat
                                           straw, fermentation residues
           with bio-diesel production                  soy hulls, rapeseed straw, pressing
                                                       cake
           in a classic crude oil refinery:            co-feeding opportunity for bio-
                                                       liquids, bio-oil syngas
3                           Independent fast pyrolysis biorefinery
    Latest interest: soil
    improvement and                                      activated carbon
    carbon sequestration                                 carbon black
                                      char
                                                         meat browning agent
                                                         smoke flavors
                                                         acids / road deicers
                                    water sol.
                                                         biolime
                                     fraction
                                                         slow-release fertilizer
                                                         wood preservatives
     biomass                                             boiler/engine/gasifier fuel
                                     bio-oil
     residues                                            adhesives
                                                         hydroxyacetaldehyde
                                   water insol.          (glycolaldehyde)
                                    fraction             levoglucosan
                                                         phenols (from lignin)
                                                         furfural (from xylose)
                                       gas               levulinic acid (from glucose)
3             Fast pyrolysis in bio-ethanol refinery

    lignocellulosic                                               chemicals
    biomass                                                       products



              hydrolysis                     fermentation   distillation

             lignin            heat,
             residue           electricity
                                                            bioethanol


              fast pyrolysis                 upgrading      transport fuels



     additional                 chemicals
     biomass                    products
3                   fast pyrolysis in bio-syngas refinery

                                                  building block
                                                  chemicals
                       oil/residue
       bio-oil                                    hydrogen
                        gasifier
                                                  methanol
                                                  mixed alcohols
                                     syngas
                                                  dimethyl ether
                                                  fischer tropsch
                       entrained
                                                  liquids
    bio-oil /char
                          flow
       slurrie
                        gasifier




                                                          17
3                               Co-feeding a petroleum refinery


biomass, in particular                                                       CONVENTIONAL
                                                                                                        conventional
                                liquefaction       deoxygenation              PETROLEUM
low-value residues:                                                            REFINERY                  fuels and
                                        by-products,                                                    chemicals
                                        residues

                                by-product                                      fuels, energy,
                                isolation /
                                                                                specialty
                                upgrading
                                                                                chemicals


     high degree of integration with existing infrastructures
     primary liquefaction (fast pyrolysis) is done at the biomass collection site while the upgrading
     (deoxygenation) could become part of the refinery

                                                                                                                     18
4                                         Catalysis in fast pyrolysis

                    in-bed catalysis                                       hot flue gas

natural catalysts                         combustor
wet impregnation                                                              ste              gas cleaning
                                                                    wood / wa
                                                                           prim. electricity
                                                                               gas
                                                                                        gas bio-oil gasification
       feed                            ex-bed catalysis                                     bio-oil upgrading
       hopper
                                                          conden-
                                                            sor
                             reactor                                          bio-oil




                                                                             bio-char



                                                                                                                   19
4                                 From bio-oil to hydrocarbons
1. natural catalyst in the biomass                         2. in-bed catalysis
    •   alkali metals such as K, Na, Ca, M                     •   immediate attack of the released volatiles
    •   high ash contents reduces bio-oil yield                •   temperature of catalysis is fixed
    •   washing of biomass leads to high                       •   catalyst can act as the process heat carrier
        concentrations of levoglucosan in the bio-oil          •   char combustor in the pyrolysis process can
    •   pretreatment of the biomass adds significantly             be a catalyst regenerator
        to the feedstock costs                                 •   In case of ex-bed: flexibility in conditions of
                                                                   catalysis such as temperature, particle size
                                                                   and shape, reactor type
3. catalytic cracking of bio-oil
    •   separate process, or co-processing in a            4. catalytic bio-oil upgrading
        traditional FCC unit                                   •   stabilization under hydrogen pressure at 250
    •   FCC of bio-oil over zeolites has been tested               to 275 oC and, after water separation,
        at 350 < T < 700 oC                                        hydrotreatment at 350 to 400 oC
    •   results similar to “in-bed” catalytic pyrolysis:       •   commercial sulphided CoMo and NiMo and
        predominantly aromatics                                    related new catalysts
    •   with coke, water and gases as by-product               •   complete deoxygenation has been achieved


                                                                                                                20
 4                         From bio-oil to hydrocarbons
                                                                            ZSM-5
In-bed / ex-bed catalytic pyrolysis
                                                                 ste
                                                       wood / wa
Products          (iso-alkanes /) aromatics + coke + CO + CO2 + H2O
                                                                        Mordenite
Reactions         dehydration, decarboxylation, isomerization,
                  dehydrogenation, oligomerization

Catalysts         FCC
examined          H-forms of zeolites: Beta, Y, ZSM-5                  Zeolite Beta
                  alumina and silica alumina
                  transition metal catalysts (Fe/Cr)
                  metal doped MCM-41 mesoporous materials


                                                                                21
4                         From bio-oil to hydrocarbons

    In-bed / ex-bed catalytic pyrolysis
                                                           CO,CO2,H2O
    Best results with HZSM-5                                50 wt %


    Theoretically maximal
    hydrocarbon yield: 55 wt%
                                      Pyrolysis oil      coke on catalyst
    energetic yield:   70 %            100 wt%             20 to30 wt%



                                                            Hydrocarbons
    Promising is the development of modified MCM-           15 to 30 wt%
    41 mesoporous materials, but hydrothermal
    stability is still very poor (rapid deactivation)

                                                                       22
                      need for 2nd generation bio-fuels
5                      boosts interest in fast pyrolysis

               FP6 European Biorefinery projects “Biocoup” and “Biosynergy”
20 million
              FP7 EU call for large (demo) projectdonasustainable biorefineries
                                               woo / w
                                                       ste
                                                          prim. electricity

                                                                    gas
                      Conoco Philips and Iowa State University alliance in the US
                                  Ensyn and UOP alliance in the US
65 million
                 DOE Core research with PNNL, NREL (VTT, Univ Houston, Ensyn)
                    Five additional projects funded by DOE, USDA, Defense Dept
             110 million $ reserved by DOE for fundamental research on 2nd gen. biofuels


                   (part of the) Supergen Bioenergy Project
15 million
                  UK Carbon Trust : The Pyrolysis Challenge



                                                                                       23
    5                         Fast pyrolysis research topics

             existing                                       “new”

- reactor development                           -   in-bed or ex-bed catalysis
-   process development pilot plant operation   -   stabilization and catalytic upgrading
                                                                          gas
-   yields and product distribution             -   chemical analysis (solvent fractionation)
-   pyrolysis kinetics                          -   fermentation of bio-oil sugars
-   single particle modeling                    -   pyrolysis of lignin residues
-   bio-oil stability (phase separation)        -   hot gas filtration
-   chemical analysis (GC and HPLC)             -   (bio) char separation
-   diesel engine / micro turbine application   -   primary products
-   bio-oil gasification                        -   techno-econ assessments
                                                -   development of standards (ASTM)


                                                                                            24
5                                             Conclusions

Liquefaction of biomass by fast pyrolysis prior to combustion and gasification is beneficial in many
ways (logistics, handling, minerals separation, etc.)
                                                                    od / waste
It offers great potential towards the production of 2nd generation o fuels electribio-chemicals
                                                                 w
                                                                   car    .
                                                                            and city
                                                                         prim
Application of catalysis in fast pyrolysis is being investigated, but progress is limited (many repetitions)
                                                                                 gas
The fast pyrolysis technology is getting mature but the bio-oil applications are still not well developed

Main RTD items today are related to car fuels production and include catalytic pyrolysis, stabilization
and upgrading, process improvement and the development of ASTM standards

Next-five-years world RTD budget ( public sector) for fast pyrolysis is estimated to be approximately
100 million euro’s, to be spent mainly in the US, Canada, Europe and China

Large scale demonstration is delayed by a lack of risk taking investors and is waiting for industrial
involvement (oil companies, food/feed companies)


                                                                                                        25

								
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