Fast Pyrolysis and Bio-Oil Upgrading Robert C. Brown Iowa State University and Jennifer Holmgren UOP
Fast Pyrolysis \u2022 Rapid thermal decomposition of organic compounds in the absence of oxygen to produce liquids, char, and gas \u2013 \u2013 \u2013 \u2013 \u2013 \u2013
Dry feedstock: <10% Small particles: <3 mm Short residence times: 0.5 - 2 s Moderate temperatures (400-500 oC) Rapid quenching at the end of the process Typical yields
Oil: 60 - 70% Char: 12 -15% Gas: 13 - 25%
Bio-Oil
Source: Piskorz, J., et al. In Pyrolysis Oils W h i t e from Biomass, Soltes, E. J., Milne, T. A., S p r u c e Eds., ACS Symposium Series 376, 1988.
Moisture content, wt%
Po p l a r
7.0
3.3
1000
590
500
497
0.65
0.48
11.6
12.2
7.8
10.8
Bio-char
12.2
7.7
Bio-oil
66.5
65.7
Saccharides
3.3
2.4
Anhydrosugars
6.5
6.8
Aldehydes
10.1
14.0
Furans
0.35
--
Ketones
1.24
1.4
Alcohols
2.0
1.2
11.0
8.5
Particle size,
\u00b5m
(max)
Pyrolysis liquid (bio-oil) Temperature from flash pyrolysis is a Apparent residence time low viscosity, dark-brownP r o d u c t Y i e l d s , w t % , m . f. fluid with up to 15 to 20%Water Gas water B i o - o i l c o m p o s i t i o n , w t % , m . f.
Carboxylic acids
Water-Soluble \u2013 Total Above 34.5
34.3
Pyrolytic Lignin
20.6
16.2
Unaccounted fraction
11.4
15.2
Multiple reaction pathways for pyrolysis of cellulose Depolymerization
Levoglucosan
Fast Alkali-catalyzed dehydration
Cellulose Slow
Char + water
Hydroxyacetaldehyde
Fast Pyrolysis • Advantages
– Operates at atmospheric pressure and modest temperatures (450 C) – Yields of bio-oil can exceed 70 wt-%
• Disadvantages
– High oxygen and water content of pyrolysis liquids makes them inferior to conventional hydrocarbon fuels – Phase-separation and polymerization of the liquids and corrosion of containers make storage of these liquids difficult
Several Kinds of Fast Pyrolysis Reactors • • • • • •
Bubbling fluidized bed Circulating fluidized beds/transport reac Rotating cone pyrolyzer Ablative pyrolyzer Vacuum pyrolysis Auger reactor
Bubbling Fluidized Bed Gas, Char, and Oil Vapors and Aerosol
• Heat supplied externally to bed Freeboard • Good mass & heat transfer Biomass • Requires small biomass Fluid bed particles (2-3 mm)
Heat
Feeder Distributor plate Fluidizing gas
Circulating Fluidized Bed/Transpo Reactor Gas and Oil Vapors and Aerosol
Pyrolyzer • Hot sand circulated between combustor Combustor and pyrolyzer Flue Gas • Heat supplied from Sand Biomass burning char & char • High throughputs Distributor but more char Hot Feeder plate Sand attrition Air Fluidizing gas
Rotating Cone Pyrolyzer Biomass • Sand and biomass Hot Sand brought into contact within rotating cone • Compact design and does not need carrier gas • Requires very small biomass particles and is hard to scale-up
Vapors and Aerosol
Rotation
Ablative Pyrolyzer • High pressure of particle on hot reactor wall achieved by centrifugal or mechanical motion • Can use large particles and does not require carrier gas • Complex and does not scale well
Spinning Disk Pressure Applied to Wood
Bio-oil Liquid Released from Wood
Vacuum Pyrolysis • Biomass moved by gravity and rotating scrappers through multiple hearth pyrolyzer with temperature increasing from 200 C to 400 C • Can use larger particles and employs little carrier gas Char • Expensive vacuum pump and difficult to scale-up
Scrapper Driver Biomass
Multiple hearth Condensers Vacuum pump vacuum pyrolysis reactor
Auger Reactor • Hot sand and biomass mixed by auger • Suitable for small scale • Requires hot sand heating and circulation system
Biomass Hot sand Vapors & aerosol to condenser
Char & sand Auger driver
Auger reactor
Relative Merits of Various Reactor Property
Status
Biooil wt%
C o mp lexity
Feed size
Demo
75
Medium
Sm all
High
Medium
Easy
CFB
Pilot
75
High
Medium
High
Large
Easy
Entrained
None
65
High
Sm all
High
Large
Easy
Rotating cone
Pilot
65
High
V small
Low
Sm all
Hard
Ablative
Lab
75
High
Large
Low
Sm all
Hard
Auger
Lab
65
Low
Small
Low
Medium
Easy
Demo
60
High
Large
Low
Large
Hard
Fluid bed
Vacuum
The darker the cell color, the less desirable the process.
I n e r t S p e c i f i c Scale gas size up need
Lab: 1 – 20 kg h - 1 Pilot: 20 – 200 kg h - 1 Demo: 200 – 2000 kg h - 1
Adapted from PYNE IEA Bioenergy http://www.pyne.co.uk
Which will dominate? TECHNOLOGY STRENGTH
Strong S S E N E V I T C A R T T A T E K R A M
Average
Weak Ablative
High
Cyclonic Rotating cone Entrained flow Fluid bed
Low
Circulating fluid bed and transport reactor Auger
Adapted from PYNE IEA Bioenergy http://www.pyne.co.uk
Fast Pyrolysis System Lignocellulosic feedstock Flue gas
Mill
Vapor, gas, char products
Hopper
Pyrolysis gases Cyclone
Pyrolysis reactor
Quencher
Char Bio-oil
Motor Feeder Fluidizing gas
Combustor
Air
Bio-oil storage
Scale
0
Diesel Output (million US gallons/yr) 50 100 150 200
250
$8,000 Small gasification (multiple units 110,000 US ton/yr) + small FT multiple units
) s r $7,000 a ll o d$6,000 S U 5$5,000 0 0 2 n o il $4,000 li (m$3,000 t s o C l $2,000 ta i p a C$1,000
Small pyrolysis (multiple units 110,000 US ton/yr) + large FT Large gasification + large FT
$400,000 pbpd
$100,000 pbpd
$0 0.0
1.0 2.0 3.0 4.0 Biomass Input (million US tons/yr)
5.0
Adapted from: Bridgwater, ACS Meeting, Washington, D.C., 2005
Suitable Feedstocks • Wide variety of feedstocks can be used • Fibrous biomass usually employed • Wood higher yielding than herbaceous biomass
Storage & Transportation
• Distributed preprocessing allows transpo and storage as liquid • High acidity requires storage in stainless steel or plastic • Stability problems need to be solved
Post Processing to Motor Fuels • • • •
Direct application of bio-oil Hydrocracking of bio-oil Gasification of bio-oil Fermentation of Bio-oil
Bio-Oil Burned in Diesel Engines
• Bio-oil used as directly as diesel fuel substitute • Only suitable for stationary power applications
Cyclone
Fibrous biomass
r e z ly ro y P
Char
Bio-oil vapor
Bio-Oil Recovery Bio-Oil
Bio-Oil Storage
Stationary Diesel Engine
Bio-Oil Hydrocracking • Directly converts biomass into liquid bio-oil (lignin, carbohydrate derivatives, and water) and char • Bio-oil catalytically converted into hydrocarbon fuel (green diesel) Green diesel
Cyclone
Char
Fibrous biomass
r e z ly ro y P
Bio-oil vapor
Bio-Oil Recovery Phase Separation Lignin
Hydrogen Steam Reformer Carbohydrate derived aqueous phase
r e k c ra c ro d y H
Bio-Oil Gasification
• Bio-oil and char slurried together to recover 90% of the original biomass energy • Slurry transported to central processing site where it gasified in an entrained flow gasifier to syngas • Syngas is catalytic processed into green diesel (F-T liquids) Cyclone
Fibrous biomass
Bio-oil vapor
Bio-Oil Recovery
r e z ly ro y P
Bio-Oil
Char
Slurry Preparation
Pump
w o l F d e in ra t n E
r ie if s a G
Slag
h c s p r ro o t T c r a e e h R c is F
Green Diesel
Bio-Oil Fermentation Distillation
Fiber
Ethanol
Hot water extraction
Pentose
Fermenter t c u d o r p y b r e b i
F
Water
Cyclone Bio-oil vapor
Char r e z ly ro y P
Bio-Oil Recovery
Detoxification Fermenter
Phase Separation Anhydrosugar & other carbohydrate
Lignin
Energy Efficiency
• Conversion to 75 wt-% bio-oil translates t energy efficiency of 70% • If carbon used for energy source (process heat or slurried with liquid) then efficiency approaches 94%
Source: http://www.ensyn.com/info/23102000.htm
Co-Products • Gas (CO, H2, light hydrocarbons)
– Can be used to heat pyrolysis reactor
• Char: Several potential applications – Process heat – Activated carbon – Soil amendment
Potential Co-Products from Bio-Oi Products of pyrolysis for several different pretreatments of cornstover (Brown et al. 20 No Pretreatment
Acid Hydrolysis
Acid Wash
Acid Wash with catalyst
Char
15.8
13.2
13.2
15.9
Water
2.57
10.6
10.4
7.96
Organics
59.1
67.2
68.5
67.7
Gases
22.6
9.02
7.88
8.44
Cellobiosan
trace
4.55
3.34
4.97
Levoglucosan
2.75
17.69
20.12
23.10
11.57
5.97
3.73
3.93
Formic acid
2.61
Trace
Trace
0.73
Acetic acid
3.40
1.51
1.26
0.40
Acetol
4.53
trace
trace
trace
Formaldehyde
2.75
1.63
trace
0.70
Pyrolytic lignin
33.40
16.89
17.74
20.08
Products (Wt% maf)
Organics (Wt % )
Hydroxy-acetaldehyde
Quality Assurance • Bio-oil quality issues:
– Moisture content – Particulate content – Sulfur and nitrogen content – Stability
Equipment Maintenance • Potential problems with pyrolysis equipment – Bed agglomeration – Clogging of condensers – ESP performance
• Catalytic reactors
– Poisoning by sulfur and chlorine – Coking
Waste Streams
• Main products (gas, char, bio-oil) accoun for all mass of biomass feedstock
Technical Barriers • Preparing dry, finely divided biomass particles • Maintaining high bio-oil yields • Improving bio-oil stability • Determining optimal scale of facility
Alternative Fuels: Targets
WTW Energy /GHG Emissions Clusters 400 400
m350 k / m300 g t, eln 250 a vi u 200 q EGasoline & Diesel 2 2 O150 C , G100 Green Diesel H G 50
0 00
200
Hydrogen from coal, FC DME from NG GTL from NG FAME Conventional EtOH Hydrogen from bio, ICE
400 600 800 Energy, MJ/km
Source: CONCAWE / EU CAR / EU Comm Comm’’n n,, Dec Dec 2003 2003
Alternative fuels fuels may targe Alternative mayneed needto to – < 100 gm /km WTW gmCO CO WTW 2/km 2 – GTL, GTL, DME DME from fromgas gas– close, but – close, but not there yet
Several other Several other alternatives alternativesininstudy stud (not shown for simplicity)
Engine manufacturers manufacturers developing Engine developing more efficient advanced ICEICE ’’s s in in addition to hybrids and FC ’s s ’ – Variable VariableDI DIgasoline gasoline – “Part Homogeneous ” diesel Part Homogeneous diesel ”
1000
combustion – “Combined Combustion ” systems Combined Combustion systems ” – Improve Improvefuel fuelefficiency efficiency
Gasoline & Diesel in Advanced ICE’’ICE Set ToughTargets! Targets! Set Tough
Biorenewables and Petroleum Feeds: Relative Availability 50 40
Global
Liquid Transport Fuels Diesel Available Oil/Grease Cellulosic Waste
14
Liquid Transport Fuels Gasoline Diesel Available Oil/Grease Cellulosic Waste
12 10
D P 88 B M66
D P30 B M 20
44
10 0
US
2
Current
Potential
0
Current
Potential
Available Cellulosic Biomass Could Make a Significant Impact in Fuels Pool
Py Oil Oil Portfolio Portfolio
Solid Cellulosic Biomass
Pyrolysis Oil/ Lignin
Gasoline Hydrogen/ Power Generation Diesel
Lignin Molecular Structure
Treating Technologies Hydrotreating • Hydrotreating is the key process to meet quality specifications for refinery fuel products • Removes sulfur, nitrogen, olefins, and metals using hydrogen • Hydrogen addition also improves the quality of distillate fuels (poly aromatics, cetane, smoke point) • Treating feedstocks for other processing units
Conversion Technologies Hydrocracking • Hydrocracking upgrades heavy feeds including gas oils and cycle oils into lighter, higher value, low sulfur products • High pressure is used to add hydrogen and produce premium distillate products • Naphtha products normally are low octane and are upgraded in a reformer • Product volume is 10-20% higher than the feedstock
Hydrocracking Catalyst Portfolio tyi vi cet el S ets al li ts i D
New Generation Current Generation
HC--215 215 HC--115 115
Flexible
DHC--8 8
Max Diesel
DHC--32 32 HC--150 150 DHC--39 39 DHC --41 41 DHC-41 HC--43 43 HC--33 33
Distillates
Max Naphtha
HC--170 170 190 HC--29 29 HC--190 HC--26 26 34 HC--24 24 HC--34
Activity
Distillate Selectivity Decreases with Increasing Activ Acti
YE forHydrocracking HydrocrackingPyrolysis PyrolysisOil Oil Feed Pyrolysis Oil H22 Products Lt ends Gasoline Diesel Water, CO22
Wt% bpd bpd 100 2,250 4--5 5 15 30 1,010 8 250 51 52 51--52
Gasoline Production from Py Oil Py Oil ($40/bbl crude)
Feed Pyrolysis Oil H22 Products Lt Hydrocarbons Gasoline Diesel Utilities Net
$/D 40,500 25,680 19,303 52,520 12,000 -4,800 4,800 12,843
$ 4.2 million/year
bpd 2,250 21.4 T 64T/D 1,010 250
Hydroprocessing costs: Effect of Scale HDT Capital Cost vs Capacity Unit size (bpd) 30000 27500 25000 22500 20000 17500 15000 12500 10000 7500 5000 2500
Cost, $MM $28.9 $27.4 $25.9 $24.3 $22.7 $20.9 $19.1 $17.1 $14.9 $12.6 $9.9 $6.5
Cost/ 1000 bpd $MM $ 0.96 $ 1.00 $ 1.04 $ 1.08 $ 1.13 $ 1.19 $ 1.27 $ 1.37 $ 1.49 $ 1.68 $ 1.97 $ 2.60
) $35.0 6 0 0 $30.0 (2
M $25.0 M $ $20.0 ,t s $15.0 o C l $10.0 ta i p $5.0 a C $0.0
0
5000
10000
15000
20000
Capacity, BPD
25000
30000
35000
Size of Hydroprocessing Units 2000 bpd HC units 2500 38.3 174072 65% 267803 Dynamotive's 200 tonne/day facility (planned production) 734 200 tonne/day biomass processed 200000 kg/day % conversion biomass to pyrolysis 65% oil 130000 kg/day biooil 1.2 kg/liter density of pyrolysis oil 108333 liter/day 30000 28622 gal/day 459.9 681 bbl/day Hydroprocessing unit 2088866 65% 3213640 8804
Dynamotive ’s s’Planned Planned 200tpd tpdPlant Plant
bbl/day M gal/year tonnes/yr tonnes/yr tonne/day plant
pyrolysis oil processed pyrolysis oil processed Conv. to biooil biomass
30,000 bpd HC unit (typical refinery size) bbl/day M gal/year tonnes/yr tonnes/yr tonne/day plant
pyrolysis oil processed pyrolysis oil processed Conv. to biooil biomass
Example: Potential from logging residues 41 Million dry tons logging residue available (Billion ton annual study) 10% % water of biomass for pyrolysis unit 46 Million tons of logging residue feed 65% % conversion to pyrolysis oil 29.6 million tons of pyrolysis oil 6519 M gallons of pyrolysis oil from logging residue 425271 bbl/day
~14 30,000 ~14 30,000 bpd bpdhydroprocessing hydroprocessingunits units – Estimated $405 MM Estimatedcost: cost: $405 MM
~170 2500 ~170 2500 bpd bpdhydroprocessing hydroprocessingunits units – Estimated $1105 MM Estimatedcost: cost: $1105 MM
Distributed Pyrolysis Plants; Centralized Refi P
Biomass
P r ie if s a G
P P
P
P
Gasification Reforming Natural Gas
DME
Integrated into tradition natural gas conversion Methanol process or refinery
Synthesis Gas
H2
GTL, BTL
Key Decision: planning to to Key Decision: What Whatare arewewe planning transport?
Technical Barriers Securing a a consistent py Oil Oil py feedstock feedstock Securing consistent Logistics Logistics
Balance of Balance of distributed distributed vs. vs.centralized centralized Catalyst and Catalyst and process process invention/development/commercialization
Summary
Vegetable oils, oil oil could b Vegetable oils, grease greaseand andpyrolysis pyrolysis coul feasible feedstocks for conventional petroleum refineries
– Other andand processing options also look Otherfeedstocks feedstocks processing options also look
promising – Increased of biobased feedstocks required Increasedvolumes volumes of biobased feedstocks require • Consistent Consistent source of of pyrolysis oil or source pyrolysis oilother or other lignocellulosic lignocellulosic
biomass
Biorenewable processing processing options Biorenewable options identified identifiedare not limited to refinery integration – Stand units possible Standalone alone units possible
• Biorefineries Biorefineries; Biofeedstock source Biofeedstock ; source • Portable Portable HH 22
Acknowledgements DOE, Project DE -FG36 --05GO15085 FG36 05GO15085 Contributors MTU MTU
– David DavidShonnard Shonnard
NREL NREL – Stefan StefanCzernik Czernik – Richard RichardBain Bain
Contributors PNNL PNNL – Doug Doug Elliott Elliott – Don Don Stevens Stevens UOP UOP – Tom Kalnes Kalnes – Terry TerryMarker Marker – Dave Dave Mackowiak Mackowiak – Mike Mike McCall McCall – John John Petri Petri
Project Manager: Rich Marinangeli
