Project Engineers: Federico Berruti Matt Klaas Sara Rohani Project Supervisor: Dr. Barghi Bio-Oil...
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Transcript of Project Engineers: Federico Berruti Matt Klaas Sara Rohani Project Supervisor: Dr. Barghi Bio-Oil...
Project Engineers:Federico Berruti
Matt KlaasSara Rohani
Project Supervisor: Dr. Barghi
Bio-Oil Production from Dry Distiller’s Grain in a Bubbling Fluidized Bed Reactor
497 Final Presentation
March 19, 2009
Department of Chemical & Biochemical Engineering, The University of Western Ontario, London Ontario, CANADA
Outline
OUTLINE | 02
• Motivation & The Need
• Plant Location and Capacity
• Introduction to Biomass, Bio-Oil & Pyrolysis
• Process Flowsheets
• Detailed Unit Designs
• Process Safety
• Economics
• Conclusion & Recommendations
• Acknowledgements
Motivation & The Need
MOTIVATION | 03
• Global Warming
• Depleting Conventional Fossil Fuel Reserves
• Volatile Conventional Oil Prices
• Global demand for alternative sources of renewable carbon dioxide neutral energy and for green chemicals.
• Demand for increased utilization of agricultural by-products & waste.
• Demand for reduced emissions from agricultural practices (e.g. rice-straw and flax straw combustion).
Motivation Continued
Raw Materials
Energy
Chemical Operation/Process
Products
WASTE
Green Process
Energy
Useful Chemicals
$$$
MOTIVATION | 04
One Possible Solution
SOLUTION | 05
• Conversion of Agricultural Crops, Waste & other Biomass sources into Bio-Oil via Intermediate or Fast Pyrolysis.
Plant Location & Capacity
PLANT PROPOSAL | 06
• Process 200,000 kg/day of DDG
•30,000 tonnes Bio-Oil annually
• Locate in Sarnia, Ontario
• Partner with Northern Ethanol, Inc. (DDG Supply)
• Located in Sarnia, transportation costs minimum.
• Desire elimination of DDG by-product, since
market saturated.
Introduction: Biomass
BIOMASS INTRO | 07
• Composite material made up of oxygen-containing components
• Renewable & carbon dioxide neutral.
• Created by fixing atmospheric carbon dioxide during photosynthesis.
• Not ideal for direct energy conversion.
•Examples: straw, husks, sugar-cane, wood, etc.
Introduction: Bio-Oil
BIO-OIL INTRO | 08
• Produced from Biomass (by-products or waste).
• Dark, brown, strongly scented, liquid.
• Complex mixture of many organic components, water, etc.
• Can be single-phase or a two-phase mixture:
• Viscous, lignin-containing, phenolic oily fraction.
• Carbohydrate-rich water fraction.
• Can be used as:
• Type II fuel (17-20 MJ/kg or 60% of hydrocarbon oil).
• Flavouring & Colouring Agent (BBQ sauce & meat colouring).
• Source of chemicals or pharmaceuticals.
Bio-Oil Composition
BIO-OIL COMPOSITION | 09
• Water
• Acids
• Phenolics
• Anhydrosugars
• Carbonyls
• Furfurals
• Subject to aging at temperatures > room temperature
• Can be stabilized with methanol & ethanol
Introduction: Pyrolysis
PYROLYSIS INTRO | 10
• Definition: Thermochemical decomposition of organic matter at high temperatures in the absence of oxygen.
• Pyrolyzed biomass converts into vapours & char.
• Char (containing carbon & inorganic ash) can be separated.
• Vapours can be rapidly quenched yielding Bio-Oil & uncondensable gases.
• Gases contain light hydrocarbons.
Pyrolysis Processes & Yields
PROCESSES & YIELDS | 11
Process OperatingConditions
Bio-OilYields
CharYields
Gas Yields
Slow Pyrolysis
T ≈ 400°CTime ≈ hours <5% ~50% ~45%
IntermediatePyrolysis
T ≈ 300-600°CTime ≈ 10-30
seconds~40% ~20% ~40%
Fast Pyrolysis
T ≈ 300-600°CTime < 1 second ~75% ~15% ~10%
Choice Criteria (Scott et al, 1999)
CHOICE CRITERIA | 12
1. Simple.
2. Low Capital Investment.
3. Economical plant needs to be sited where raw materials can be easily supplied at a reasonable or no cost.
4. Should operate at the minimum possible temperature (maximizing desired product yield)
5. Bio-Oil quenching requirements are minimized using the smallest possible gas to biomass feed ratio.
6. Should be easy to scale-up.
Pyrolysis Technologies
TECHNOLOGIES | 13
Reactor Type
Simple Capital Expense
Low Temperature
Low Gas/Solid
Ratio
OperatingExpense
Easy Scale-up
BubblingFluidizedBed
Very Good
Excellent Very Good Good Very Good Excellent
CirculatingFluidizedBed
Fair Good Very Good Poor Fair Very Good
RotatingCone Fair Good Very Good Very Good Fair Poor
VortexAblative Fair Very Good Very Good Excellent Good Very Poor
VacuumProcesses Fair Excellent Excellent Excellent Poor Very Good
EntrainedFlow Excellent Excellent Very Good Very Poor Poor Excellent
Process Flowsheet: Overall
OVERALL PROCESS | 14
Process Flowsheet: Feeding
INJECTION | 15
SECTION 100
Process Flowsheet
PROCESS SHEET | 16
SECTION 200
CY = CycloneT = TankHE = Heat Exchanger
Process Flowsheet: Condensation
CONDENSATION | 17
SECTION 300
Process Flowsheet: Overall
PRINCIPLE REACTOR | 18
Pyrolysis Reactor/Furnace Overview
REACTOR OVERVIEW | 19
• Unit where the Biomass is converted to Bio-Oil Vapours,
Gases, Ash & Char via Fast Pyrolysis
• Novel Annular Reactor with Core Furnace Design
• Fluidized Bed Selected
• Based on Choice Criteria previously discussed
• New Patented Lift Tube Technology utilized for heat transfer
• Insulated Outer Shell using FiberFrax
Pyrolysis Reactor Assumptions
REACTOR ASSUMPTIONS | 20
Potential Problems & Solutions
• High Temperature – Control required (Lift Tubes Technology, Oxygen Probe
S-236)
• Risk of Explosion (Plugging) – Pressure Relief Valve & Burst Plate Required
• Monitor fluidization regime to ensure proper mixing and no hot spots.
List of Assumptions
• Dry distiller’s grain composition assumed (Jacobson, 2007)
• Heat losses of 15%
• The reaction energy of 1.058 MJ/kg (Jacobson, 2007)
• A 20L gas capacitance volume of injection
• Average Heat capacities calculated & assumed constant
• Yields assumed from literature
• The sand return energy considered immaterial
• Sand has a dpsm=169μm & ρ=2500 kg/m3
Pyrolysis Reactor/Furnace Overview
REACTOR M&E | 21
PROCESS UNIT & NAME: Principal Reactor (R-201)
IN DIAGRAM OUT
Stream T (K)P (kPa)
Material Mass(kg/s)
Power (kW)
Tref = 25°C
*Note: The power requirements do not
correlate perfectly due to approximations of heat capacities from
literature.
Stream T (K)P (kPa)
Material Mass(kg/s)
Power (kW)
Tref = 25°C
S-115 298.72135.8
DDGN2
2.310.0087
2.240.0056
S-202 723.15109.0
Bio-OilN2
CH4CO2COH2
Char/Ash
1.162.8
0.230.190.460.050.23
739.501,333.12386.7194.27
222.46311.8782.11
S-224473.1109.0 N2 2.79 547.0
S-209873.1135.8 Sand Neglect 0
RXN 723.15 Pyrolysis 2,450.4
Total 5.1 2,999.6* Total 5.1 3,170.0*
Pyrolysis Reactor Design
REACTOR DESIGN | 22
SIDE VIEW TOP VIEW
Pyrolysis Reactor Design
REACTOR DESIGN| 23
Annual Reactor
Furnace CoreSIDE VIEW
TOP VIEW
Pyrolysis Reactor Design
REACTOR DESIGN | 24
LIFT TUBE TECHNOLOGY:
Pyrolysis Reactor Design
DESIGN DETAILS | 25
Design Details
• Reactor Operating Temperature = 450°C
• Furnace Operating Temperature = 800°C
• Reactor/Furnace Operating Pressure = Approx. 1 atm
• Wall Thickness = 0.5” (Peters, 2003)
• Material of Construction: Inconel 600
• Temperature resistance, little fouling, corrosion proof, structural
stability, high thermal conductivity
• Construction Cost Quote = ~$200,000 (Gudgeon Thermfire Inc.)
• Total Capital Investment = ~$1.2 Million
•593% of Construction Cost (includes installation, piping, labour,
instrumentation, etc.)
Pyrolysis Reactor/Furnace Control
REACTOR CONTROL | 26
Main Control:
• PI Controller Selected
• Type K Thermocouples
• Oxygen Probe (DS-300)
Minor Control:
• Omega PX-82-MV Pressure
Transducers
• Pressure Gauges
• High Temp/High Pressure
Alarms
• Fluidization Flow Control
Process Flowsheet: Overall
REGENTERATION | 27
Regeneration Reactor Overview
REGENERATION OVERVIEW | 28
•Regeneration of sand from pyrolysis reactor
•Fluidized bed
•Mixture of sand, char and ash from pyrolysis
reactor injected
•Char is burned
•Ash is entrained
•Sand is returned to pyrolysis
reactor via standpipe
Regeneration Reactor Assumptions
ASSUMPTIONS | 29
Potential Problems
• High temperature (combustion reaction) – Must control reactor temperature
and must be able to stop feeding in case of overheating
• Particle entrainment – Use baffles in reactor to block sand particles; ash
particles will still be able to escape the reactor
List of Assumptions
•Heat losses of 15% of heat of combustion
•Heat capacities used are taken at average temperatures
•Sand and ash have same heat capacity
•Injection nitrogen has negligible effect on energy balance
•Complete combustion
•Char is purely carbon
•No sand entrained
•Combustion at 400°C
Mass & Energy Balance: Regeneration Reactor
REGENERATION M&E | 30
PROCESS UNIT & NAME: Sand Regenerator (R-202)
IN DIAGRAM OUT
Stream T (K)P
(kPa)
Material Mass(kg/s)
Power (kW)
Tref = 25°C
Stream T (K)P (kPa)
Material Mass(kg/s)
Power (kW) Tref = 25°C
S-207 673128.8
N2
CharSandAsh
0.00170.140.070.09
0.0544.1
22.0528.35
S-212 1304108.2
AirN2
CO2
Ash
0.991.22
0.5130.09
1061.791473.09516.5776.08
S-238373
108.9Air 2.6 208.07
*Note: The values are not the exact same due to assumptions in heat
capacity
S-2081034170.2
Sand 0.07 59.17
Reaction 373 2800
Total *3102.62 Total *3186.69
R-202
S-207
S-208
S-238
S-212
Regeneration Reactor Design
REGENERATION DESIGN | 31
3.5m
1.5m
Wall Thickness: 0.5”
Regeneration Reactor Design
REGENERATION DESIGN | 32
Design Details
• Reactor Operating Temperature = 1031°C
• Operating Pressure ~ 1atm
• Wall thickness = 0.5”
•Construction Material:
•Inconel 625 (high temperature)
•Maintains good properties well over 1000°C (essential)
•Construction Cost:
• $63,000
•Total Capital Investment:
• $373,590 (Includes 593% adjustment for associated costs)
Regeneration Reactor Control
REGENERATION CONTROL | 33
Main Control:
• Type K Thermocouples
appropriate for high
temperatures
•PI controller
•Eliminate offset
•Acceptable speed
Minor Control:
• Pressure transducers, gauges
• Ensure proper reactor
functionV-217
Process Flowsheet: Overall
AIR COOLER | 34
Air-Cooled H.E. Overview
AIR COOLED H.E. OVERVIEW | 35
• A series of heat exchangers are used to cool down the product gases
• The water used in the third heat exchanger (HE-303) needs to be cooled down
• Need for a suitable, environmentally friendly solution
Air Cooling
ALTERNATIVES | 36
• Chosen because of:
• Environmental impact
• Lower water consumption
• No danger of water pollution
• Lower maintenance and piping costs
• Less corrosion, fouling issues
Air Cooled H.E. Design
DESIGN CONSIDERATIONS | 37
Considerations
• Must be able to handle winter and summer conditions
• Temperature constraints
Design Assumptions
• Near constant temperature (25C)
• Average heat capacities calculated and assumed constant
• Negligible fouling on air side
Mass & Energy Balance
AC M&E | 38
PROCESS UNIT & NAME: Heat Exchanger (AC-301)
IN DIAGRAM OUT
Stream T (K)P (kPa)
Material Mass(kg/s)
Power (kW) Tref = 25°C
Stream T (K)P (kPa)
Material Mass(kg/s)
Power (kW) Tref = 25°C
S-319 358.15218.6
H2O 13 3264 S-320 318.15204.8
H2O 13 1088
S-327 298.15 Air 144 0 S-328 313.15 Air 144 2186
Total 157 3264 Total 157 3274
Air Cooled H.E. Design Details
DESIGN DETAILS | 39
• Fin type: Integral
• Copper alloy tubing with
aluminum fins
• Dimensions:
• Triangular 2.5 in. pitch
• 4 tube rows, 2 tube passes, 3 sections, 38 tubes per row
• Total surface area required: 50,500 ft2
• Available surface area: ~66,000 ft2
• Cost: $356,080
Fins per in.: 9
Fin height: 0.5 in
Fin thickness: 0.019 in.
Air Cooled H.E. Design
DESIGN DETAILS | 40
• Air flow: Induced draft
• Better air distribution
• Fan power requirement: 6 fans with 5 kW each
Control Strategy
AIR COOLER CONTROL | 41
• Control objectives:
• Control outlet temperature of water
• Monitor process
Water in
Air
Variable speed motor
TT-2
TT-1
FT-2
Water out
SC
FT-1
FT: Flow TransmitterSC: Speed ControllerTT: Temperature Transmitter
HYSYS Simulation Check
HYSYS | 42
Bio-Oil Composition Mass FractionsGlyoxal 4.88%AcetAldehyde 2.24%H2O 32.94%CO2 0.02%CO 0.00%Methane 0.00%Hydrogen 0.00%Ethanol 15.99%FormicAcid 4.37%AceticAcid 5.72%Glycerol 9.00%Nitrogen 0.00%Acetol 7.23%Oxygen 0.00%Glucose 17.61%DDG 0.00%
Process Inherent Safety
INHERENT SAFETY | 43
• Entire plant operated essentially as an open system
• All units operate at a low pressure
• Harmful vapours combusted for energy and not
released into the environment
• At any given time, there is only a small amount of
hazardous gas since it is continuously combusted
• Natural gas utility used for start-up and heating
instead of stored propane
Process Safety Overview
LOPA | 44
Physical Protection-rupture disks-relief valves
Process Design Inherent Safety
Critical Alarms and Operator intervention-High temperature alarm-High pressure alarm
Process Economics
CAPITAL INVESTMENT | 45
Equipment Cost
Principal Reactor (R-201/FU-201) $ 1,186,000
Regeneration Reactor (R-202) $ 373,590
Storage Tanks & Hoppers (T-xxx, HO-xxx) $ 3,391,960
Heat Exchangers (HE-xxx, AC-301) $ 429,984
Pumps (P-xxx) $ 83,200
Blowers (B-xxx) $ 637,000
Cyclones (CY-xxx) $ 117,000
Total Capital Investment $ 6,218,734
Total Capital Investment
Process Economics
PROCESS ECONOMICS | 46
Expense Annual Cost
Raw Materials (DDGs, Sand) $ 26,193
Utility Costs $ 756,410
Labour/Staff Costs $ 936,000
Maintenance $ 373,124
Operating Supplies $ 55,968
Overhead $ 785,474
Insurance and Property Taxes $ 124,374
Administrative Costs $ 196,368
Research and Development $ 152,877
Distribution and Sales $ 305,754
Total Annual Operating Costs $ 3,712,546
Annual Sales Revenue* $ 5,468,750
Annual Net Income** $ 737,314
Annual Free Cash Flow $ 1,359,188
*Bio-Oil priced at $35/barrel
**After tax & depreciation
Process Economics
RETURNS & SENSITIVITY | 47
• Payback Period = 4.58 Years
• Discounted Cash Flow IRR = 21%
• Sensitive to Market Price of Bio-Oil
• Break-even at $20/barrel
• Sensitive to deals with Northern Ethanol Inc. and agricultural producers to obtain cheap or free biomass byproducts or wastes.
Conclusions & Recommendations
CONCLUSIONS | 48
• Based on this study, project appears very feasible & profitable
• Novel reactor design maximizes heat transfer efficiency
• Overall process very energy efficient
• Significant heat recovery & waste recycling
• Significant safety considerations implemented
• Recommend to WENCOR for intensification study:
• Pinch Analysis
Acknowledgements
ACKNOWLEDGEMENTS | 49
The authors of this report wish to express their most sincere appreciation to Professor Barghi for his insight and direction in this project. In addition, they wish to thank Prof. C. Briens, Prof. F. Berruti and Dr. L. Ferrante for their knowledge and assistance.
QUESTIONS?
Acknowledgements
ACKNOWLEDGEMENTS | 47
Process Safety Overview
HAZARD ASSESSMENT
Chemical Fire Hazard Health Hazard
Corrosive Flash Point (°C)
Auto-Ignition Temp (°C)
Prolonged Inhalation
Nitrogen No No No N/A N/A None
DDG Yes No No N/A N/A N/A
Carbon Monoxide
Yes Yes No N/A 620 Confusion, nausea, unconsciousness, death
Carbon Dioxide
No No No N/A N/A Asphyxiation, circulatory collapse
Methane Yes Yes No N/A 580 Asphyxiation, nausea, unconsciousness, muscle failure
Hydrogen Yes No No N/A 570 Explosion Risk
Bio-Oil Yes Yes Yes 50 500 Severe irritation