upgrading of bio-oils from biomass with catalytic ... · advantages disadvantages . the catalyst...
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Nikos Papayannakos, Professor National Technical University of Athens
School of Chemical Engineering Unit of Hydrocarbons and Biofuels Processing
Upgrading of Bio-oils from Biomass with Catalytic Hydrotreatment
8 March 2013
UGent Francqui Chair 2013 / 4th Lecture
Introduction Ligocellulosic Biomass Conversion to Liquid Bio-Oils Hydrotreatment of Bio-Oils Pre-treatment Post-treatment Co-Processing Current trends in research Conclusions
Outline UGent/FCh13/4L
8 March 2013
Biomass : Sustainable Feedstock
Can replace diminishing fossil Fuels to produce
Energy Chemicals
Three General Classes of feedstocks derived from Biomass
Starchy Lignocellulosic
Oils
Biomass UGent/FCh13/3L
8 March 2013
UGent/FCh13/4L
• Polysaccharides with a-glycosidic bonds • Structural Units : Glucose • Solar Energy Store
Amylopectin 75 – 80 wt %
Amylose 20 – 25 wt %
Linkages
α (1-6)
Linkages
α (1-4)
Easily hydrolyzed into the constituent sugar monomers
BIOETHANOL 1st Generation Biofuel
The easily processed Sugars and Triglycerides are only a small part of the Biomass Poor Energy Yields
Starchy Feedstocks UGent/FCh13/4L
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Disadvantages of 1st Gen. Biofuels
Lignocellulosic biomass is :
• Inexpensive and The most abundant class of Biomass • Present in all plants contributing structural integrity
Lignocellulosic Biomass is comprised of :
Cellulose is a crystalline, strong and resistant to hydrolysis Polysaccharide with b (1-4) glycosidic linkages
Hemicellulose is a Polysaccharide with a random Structure and little strength. It is easily hydrolyzed by dilute acids, bases and enzymes
Lignin is an amorphous Polymer composed of methoxylated phenylpropane structures
40 – 50 wt % 25 – 35 wt %
15 – 20 wt %
Lignocellulosic Biomass UGent/FCh13/4L
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• Convert the solid biomass into Gas or Liquid platforms • Partial removal of Oxygen
The goal of converting lignocellulosic biomass to hydrocarbon fuels
Remove Oxygen Increase the energy density
Control MW / formation C-C bonds
Catalytic Upgrading to final Biofuel • Removal of the remaining Oxygen • C-C coupling controlled reactions
1st Step / Conversion
2nd Step / Upgrading
Thermochemical Hydrolysis Sugar monomers/ Upgradable intermediates
Whole Biomass Deconstruction
Biomass Conversion UGent/FCh13/4L
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Final BIOFUEL
Pathways to convert sugars and polyols to biofuel through production of monofunctional intermediates1,2
1 E. L. Kunkes, D. A. Simonetti, R. M. West, J. C. Serrano-Ruiz, C. A. Gartner and J. A. Dumesic, Science, 2008, 322, 417–421 2 David Martin Alonso, Jesse Q. Bond and James A. Dumesic Green Chem., 2010, 12, 1493–1513
Hydrolysis Routes UGent/FCh13/4L
8 March 2013
Hydrolysis Route through Sugar/Polyols Monomers
Reaction pathways to upgrade HMF by aldol-condensation to liquid alkanes
G.W. Huber, J.N. Chheda, C. J. Barrett and J. A.Dumesic, Science, 2005, 308, 1446–1450
Hydrolysis Routes UGent/FCh13/4L
8 March 2013
Most Important Technologies of thermo-chemical conversion for Liquid Biofuel production
Gasification
Pyrolysis
Production CO/H2
F-T Conversion Into linear CxHy
Finishing - Isomerization
Fast Pyrolysis
Slow Pyrolysis
Bio-oil Production
Char Production
Bio-oil Hydrotreatment
Hydrothermal Liquefaction
Bio-oil Production In the presence of water
Bio-oil Hydrotreatment
Processes for Liquid Biofuels UGent/FCh13/4L
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BIOFUEL
BIOFUEL
BIOFUEL
Thermochemical Conversion of Biomass
Thermochemical Processes UGent/FCh13/4L
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R.W. Nachenius, F. Ronsse, R.H. Venderbosch, W. Prins Advances in Chemical Engineering, Vol. 42, Burlington: Academic Press, 2013, pp. 75-139
Composition of Pyrolysis Bio-Oils
The exact composition depends on the • Biomass Soure and • Process Conditions
A Typical Composition of a Bio-Oil : Pyrolitic lignin and suspended solids : 22-36% pH : 1.8 – 3.8 Water : 20-28% Density : 1.2 – 1.3 g/cm3 Hydroxyacetaldehyde : 8-12% Oxygen : 40 – 50 % Levoglucosan : 3-8 % LHV : 10 – 15 MJ/Kg Acetic Acid : 4-8% Cetane N. : 10 Formic acid : 3-6% Formaldehyde : 3-4% Acetone : 3-6% Cellobiosan : 1-2% Glyoxal : 1-2%
They contain : Acids, Alcohols, Ketons, Aldehydes, Phenol
http://en.wikipedia.org/wiki/Pyrolysis_oil
Composition of Bio-Oils UGent/FCh13/4L
8 March 2013
The most common types of molecules in Bio-oils from Lignin derive from the building blocs of Lignin ( Monolignols )
Monolignols UGent/FCh13/4L
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The most common types of linkages in bio-oils from Lignin
β-O-4 linkage
OCH3
OOH
HO
O
OH
CH3
1) Aryl ether β-O-4 linkage between one aromatic ring and an oxygen atom that is bounded to a carbon atom of an alkyl substitute of another aromatic ring
2) Phenylcoumaran β-5 linkage between one aromatic ring and the carbon atom of the coumaran ring.
Linkages in Lignin derived molecules UGent/FCh13/4L
8 March 2013
β - 5 linkage
3) Biphenyl 5-5’ linkage between two different aromatic rings
O
OH
HO
OH3C
CH3
HOOC
COOH
5-5’ linkage
4) Pinoresinol β-β linkage between two tetrahydrofurans which are bonded together but also to an aromatic ring each
OH
OH3C
O
O
HO
OCH3
β-β linkage
UGent/FCh13/4L
8 March 2013
Linkages in Lignin derived molecules
5) Dibenzodioxocin 5-5-O-4 linkage between two aromatic rings but also between an aromatic ring and a carbon atom of a methoxy group attached to another ring.
5-5-O-4 linkage
O
OCH3
COOH
COOH
O
CH3O
CH2OH
HO
OH3C
UGent/FCh13/4L
8 March 2013
Linkages in Lignin derived molecules
Typical Gas Composition at various pyrolysis temperatures
Wang X., Kersten SRA., Prins W., van Swaaij WPM. Ind. Eng. Chem. Res., 2005, 44(23), 8786-8789
Pyrolysis Gas Composition UGent/FCh13/4L
8 March 2013
Properties of the Pyrolysis Bio-Oils
After Fast Pyrolysis the bio-oil shows some intrinsic disadvantages for its use as a neat biofuel or in blends with other petroleum fractions
These drawbacks are strongly related to the Pyrolitic Lignin molecules and
the functional groups of the existing compounds
Bio-oil tends to polymerize during long storage periods It has poor heating value It has poor thermal stability It is non-volatile It has high viscosity It is highly corrosive due to the presence of carboxylic acids It is immiscible with fossil fuels (diesel)
Characteristics of Bio-Oils UGent/FCh13/4L
8 March 2013
Basic Characteristics :
Bio-Oil Pretreatment
For the effective HDT and storage of the Bio-oils stabilization is attempted
Catalytic treatment during pyrolysis
Catalytic Post-treatment after Pyrolysis
Advantages
Disadvantages The catalyst operates ONLY at Pyrolysis conditions
The catalyst can operate at Different conditions One step Process
Another reactor is needed After Pyrolysis
The composition and the properties of the final Bio-Oil Depend on the biomass feed material, the pyrolysis conditions and the stabilization treatment
Aging is accelerated with temparature because polymerization reactions are promoted
Alternative pretreatments UGent/FCh13/4L
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Raw material, catalyst and reaction conditions of pyrolysis – stabilization Processes
Hydrotreatment of Bio-Oils
Efficient Design and Operation of Hydrotreaters
A good knowledge of the chemical composition of Bio-oils
What are the compounds (group) or the functional groups/structures that control aging and instability? How can we eliminate them or their action? How can we minimize the Oxygen amount in the final Bio-Oil?
Hydrotreater simulation UGent/FCh13/4L
8 March 2013
Before Hydrotreatment the pre-treatment process must be controlled
Alternatives in Hydrotreating
Mild Hydrotreatment
• Stabilization • Production of oxygenated compounds
Chemicals Fuels
HDT – Hydrodeoxygenation
- Remove Oxygen - Hydrogenate Aromatics
HDT – Hydrocracking
- Reduce molecular size
Bio-Fuels
Hydrotreating UGent/FCh13/4L
8 March 2013
Co-Process with Petroleum Fractions
Elliott D. C. WIREs Energy Environ 2013. doi: 10.1002/wene.74
Typical Flow Diagram of Bio-Oil Hydrotreatment
HTD - HC UGent/FCh13/4L
8 March 2013
Component group Feed 1 (%) O1 (%) Feed 2 (%) O2 (%) O3 (%) Unsaturated ketones/aldehydes 3.37 0.98 4.46 0.00 0.39
Carbonyls (hydroxyketones, aldehydes)
9.27 3.27 9.36 0.00 0.00
Total alkanes 0.00 9.86 0.00 4.45 3.18 Saturated guaiacols (diol,ones) 0.00 0.15 0.00 0.29 0.71
Phenol and alkyl phenols 10.27 13.86 6.83 18.55 26.67
Alcohols and diols 3.50 4.62 9.31 5.29 1.94
HDO aromatics 0.00 0.81 0.00 0.87 0.27 Total saturated ketones 1.13 21.00 0.96 25.08 17.68
Total acids and esters 19.78 23.43 41.81 25.21 25.68
Total furans and furanones 8.50 1.09 3.01 2.19 1.52
Total tetrahydrofurans 3.18 3.26 2.88 4.65 2.35
Complex guaiacols 26.40 9.49 8.34 4.57 7.70 Guaiacol and alkyl guaiacols 7.77 5.00 6.71 5.41 6.70
Unknowns 6.83 3.17 6.32 3.44 5.21 Total 100.00 100.00 100.00 100.00 100.00
Composition of Feeds and hydrotreated products ( O1, O2 and O3)
Douglas C. Elliott*, Todd R. Hart, Gary G. Neuenschwander, Leslie J. Rotness, Alan H. Zache Environmental Progress & Sustainable Energy, 2009, 28(3) 441-449
HDT-Feed and Product Composition UGent/FCh13/4L
8 March 2013
Component groups O1 (%) O2 (%) O3 (%) O4 (%) Feed 1 (%) Unsaturated ketones 0.00 0.00 0.00 0.00 0.00 Carbonyls (hydroxyketones) 0.00 0.00 0.00 0.00 0.00
Naphthenes 70.77 67.88 69.67 71.63 4.22 Saturated guaiacols (diol,ones) 0.00 0.00 0.00 0.00 0.00
Phenol and alkyl phenols 0.00 0.00 0.00 0.00 15.68
Alcohols and diols 0.00 0.00 0.00 0.00 22.67 HDO aromatics 12.02 14.05 11.53 12.82 10.51 Total saturated ketones 0.00 0.00 0.00 0.00 12.84
Total acids and esters 0.00 0.00 0.00 0.00 11.89
Total furans and furanones 0.00 0.00 0.00 0.00 0.00
Total tetrahydrofurans 0.00 0.00 0.00 0.00 3.28
Complex guaiacols 0.00 0.00 0.00 0.00 0.00 Guaiacols/syringols 0.00 0.00 0.00 0.00 18.91 Straight-chain/branched alkanes
11.72 13.62 13.18 10.32 0.00
Unknowns 5.49 4.45 5.62 5.24 0.00 Total 100.00 100.00 100.00 100.00 100.00
And otred Composition of Feed1 products ( O1, O2, O3 and O4) after hydrocracking
HC – Feed and Product Composition UGent/FCh13/4L
8 March 2013
Richard J. French, Jim Stunkel, and Robert M. Baldwin Energy Fuels 2011, 25, 3266–327
Blending strategies for bio-oil in the petroleum refinery
Co-Processing Strategy : Mild hydrotreating (where moderate levels of deoxygenation take place) coupled with co-processing in a petroleum refinery
Co-Processing UGent/FCh13/4L
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Dist Col
Current Process development Efforts focus on Catalytic Hydroprocessing
FEEDS - Studies with Model Compounds More fundamental Chemistry questions - Studies with real Bio – Oils Estimation of process characteristics Scaleup Data – Feasibility - Sustainability
CATALYSTS - Traditional sulphided Catalysts
- Non- traditional precious metal catalysts
Much, but not all, of the required hydrogen can be produced from reforming of the gas by-products
Current Research UGent/FCh13/4L
8 March 2013
As real feeds are difficult to handle, model compounds representing the bio-oils’ most common or refractory molecules are examined.
MODEL COMPOUNDS
Aliphatic H/C Aromatic H/C
Carboxylic acids
Low MW ketones
Low MW aldehydes
Phenols (substituted or not)
Benzaldehydes Benzoketones
Primary Concern : Activity, Selectivity, Reaction Mechanism HDO of Functional Groups with Low MW molecules
Model Compounds UGent/FCh13/4L
8 March 2013
Phenolic C – O bond Is the most difficult to rupture
DeOxygenation Step – Catalyst Selectivity
Direct hydrogenolysis should be avoided - Aromatics
Hydrogenation route produces saturated HC
Weiyan Wang, Yunquan Tang, Hean Luo, Wenying Liu Reac Kinet Mech Cat, 2010, 101, 105-115
Studies – Model Compounds UGent/FCh13/4L
8 March 2013
V. N. Bui, D. Laurenti, P. Afanasiev, C. Geantet Applied Catalysis B: Environmental , 2011, 101, 239–245
General reaction scheme for GUA conversion with transition metal sulfide catalysts
DME, demethylation; DMO, demethoxylation; GUA, guaiacol; CAT, catechol; PHE, phenol; Me-CAT, methyl-catechol; Me-PHE, methyl-phenol.
Model Compound Guaiasol UGent/FCh13/4L
8 March 2013
Tentative mechanism for HDO of Benzofuran (BF)
M.C. Edelman, M.K. Maholland, R.M. Baldwin, S.W. Cowley, J. Catal. 111 (1988) 243.
BF
Model Compound Benzofuran UGent/FCh13/4L
8 March 2013
Possible reaction pathways for furfural conversion over Cu, Pd and Ni catalysts
N. Joshin, A. Lawal Chemical Engineering Science , 2012, 84, 761–771
Catalysts : 1% Pd/SiO4 5% Ni/SiO4
Selectivity of products from Furan Decarbonylation and ring opening (RO) (BAL+BOL+Butane) reactions
Model Compound : Furfural UGent/FCh13/4L
8 March 2013
Furfural (FAL)
Most Common Reactions during Hydrotreatment
DEMETHYLATION REACTION CH3
+H2 + CH4
METHYLATION REACTION OH
+ CH3-
OH
Me
DEHYDROXYLATION REACTION
OH
OCH3
OH
CH3
+ H2O
HDT Reactions 1 UGent/FCh13/4L
8 March 2013
HYDROGENOLYSIS REACTION
O + H2 OH
CH3
+ H2 + CH3-CH3
DEMETHOXYLATION REACTION
OH
OCH3
+ H2
OH
+ CH3OH
+ CH4 + H2O
OH
OH
HDT Reactions 2 UGent/FCh13/4L
8 March 2013
DECARBONYLATION REACTION
+ H2 OH
O
O
+ CO
AROMATIC RING OPENING REACTION
O
+ H2
O
H
KETO-ENOL TAUTOMERISM REACTION OH O
HTD Reactions 3 UGent/FCh13/4L
8 March 2013
CONDENSATION REACTION
H
OH+
CH3
+
OH
CH3
CH3
O CH3
HYDROGENATION REACTION
+ H2
HDT Reactions 4 UGent/FCh13/4L
8 March 2013
CATALYTIC MATERIALS TESTED
SUPPORTS
• SiO2 • γ-Al2O3 • ZSM-5(mesoporous/microporous) • HBEA • C • HZSM-5 • ZrO2 • CeO2-ZrO2 • SiO2-ZrO2-La2O3 • Amorphous borohydrites.
• Fe • Cu • Pd • Ni • Ga • Pt • Rh Bimetallic • CoMo • NiMo • RhPt • RhPd • PtPd • NiCu
ACTIVE METALS Monometallic
HDT Catalysts UGent/FCh13/4L
8 March 2013
LHSV : 0.1 – 40 h-1
Reaction Time : 1 – 20 h
Furfural Phenol
Benzaldehyde Acetophenone
Guaiacol o-m-p-cresol Dibenzofuran
Anisole Cyclohexanone Cyclohexanol
Model Compounds
Experimental Conditions
Reactor Type - Batch - Tubural - Continous
Pressure : 0.1 – 17 MPa Temperature : 170 – 400 0C
HDT Experiments UGent/FCh13/4L
8 March 2013
Catalyst amount used: 15-1500 mg
• Most of the research on Bio-Oils concerns the HDT of model compounds with one or more O-containing functional groups
• The most difficult to DO compounds are Phenols
• Catalysts with various selectivities have been tested and a spectrum of different molecules are produced from the various functional groups
• The design of the Bio-oil hydrotreaters and the strategy to reach the final biofuel strongly depend on Pyrolysis conditions and Biomass type
• The viable operation of an industrial process for biofuels production from biomass is strictly related to prediction of the performance of the Pyrolysis – Pretreatment system using various lignocellulosic raw materials
• Stabilization of the Bio-Oils after Pyrolysis is crucial for storage and further hydro-processing
• Co-feeding Bio-Oils and petroleum fractions is a promising way to reach the target of viably and sustainably produce biofuels from lignocellulosic mass in the short term
Conclusions UGent/FCh13/4L
8 March 2013