Performance of 3 ton/day BFB Gasification System using Pine Feedstock
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Transcript of Performance of 3 ton/day BFB Gasification System using Pine Feedstock
Performance of 3 ton/day BFB Gasification System using Pine Feedstock
Md Waliul Islam1
Prashanth R. Buchireddy1, Ph.D., John L. Guillory1, Ph.D., Mark E. Zappi1, Ph.D.,Jude Asonganyi1, Robert Bentley1, Derek Richard1
Ben Russo2 and Keith Crump2
1 Energy Institute, University of Louisiana at Lafayette, 2 Cleco Power, LLC.
Objectives
Optimizing the FBR gasification system to produce clean energy dense syngas for optimal power generation
Evaluation of different types of feedstock including Pine, Willow, and Arundo (Giant Reed).
Evaluation of tar reforming catalyst
Improving CO/H2 ratio for gas to liquid production
Pine Wood Chips General ApplicationsMulchHeatingWalkwaysComposting
Biomass Statistics• Louisiana’s forestlands cover 48% of the state’s
area – 13.8 million acres.• Total Biomass Resources in LA- 13,000 MT/year• Approximately 22% of homes in LA could be
powered• Approximately 30% gasoline consumption could
be replaced in LA
Ultimate Analysis Elements %Wt. (Dry Basis)
Nitrogen 0.10
Carbon 52.70
Hydrogen 7.50
Sulphur 0.30
Oxygen 39.40
Proximate Analysis* Moisture 52.3%
Ash 0.29 %
Volatile Matter 31.50 %
Fixed Carbon 15.90 %
Heating Value 8,864 btu/lb
Types of GasifierGasifier Type Advantages Disadvantages
Updraft Small pressure drop Good thermal efficiency Little slag formation
Great sensitivity to tar and moisture
Relatively long time required for start up of IC engine
Poor reaction with heavy gas load
Downdraft Flexible adaptation of gas production to load
Low sensitivity to charcoal dust
Design tends to be tall Not feasible for very small
particle size of fuel
Crossdraft Short design height Fast response time to load Flexible gas production
High sensitivity to slag formation
High pressure drop
Types of Gasifier (Cont’d)Gasifier Type Advantages Disadvantages
Moving Bed Simple operation Minimal fuel prep. High moisture tolerance
High tar content in gas High maintenance Channeling
Fluidized Bed Low tar, char in product gas
Superior mixing Tolerates broad range of
feedstock size, moisture
Intolerant of slag formation in bed
Low turndown ratio High pressure drop
Entrained Flow Relatively Compact Low Tars Minimal metal contact
with High Temperatures
Ash, Slag carry over Sensitive to fuel
preparation Refractory issues
UL Gasification SystemGasifier Type 250 lb/hr
AtmosphericBubbling Fluidized Bed
Features Semi-PortableAir/Oxygen/SteamDual Feeding Zones
Products Power Product Gas/SyngasLiquid Fuels/Chemicals
Operating ConditionsFeed Rate 110-146 lb/hrMoisture Content 13-15%Equivalence Ratio 0.25-0.33
Bed Temperature 1,520-1,720°F
Free Board Temperature 1,310-1,380°F
Bed Velocity 1.2 – 1.5 ft/s
Bed Pressure, psig 0.32-2.10 psig
Syngas Production Rate 74-98 scfm
Gasification ReactionsDrying H2O (l) H2O (g) ∆H°= +40.7 KJmol-1
Devolatilization CHxOyNz Char+ Volatiles
Combustion C+O2=CO2 ∆H°= -406 KJmol-1
Partial Oxidation C+0.5O2=CO ∆H°= -268 KJmol-1
Boudouard C+CO2=CO ∆H°= +172.6 KJmol-1
Water-Gas C+H2O= CO+H2 ∆H°= +131.4 KJmol-1
CO Shift CO+H2O=CO2+H2 ∆H°= -42 KJmol-1
Methanation C+2H2=CH4 ∆H°= -75 KJmol-1
0 50 100 150 200 250 300 350 400 4500
200
400
600
800
1000
1200
1400
1600
1800
2000Temperature Profile of FBR
Time (Minute)
Tem
pera
ture
, °F
Gasification
Cooling
Combustion
HHVProduct gas=(3XCO+ 2.57XH2+8.54XCH4)x4.2+46
1520 1560 17200.0
5.0
10.0
15.0
20.0
25.0Bed Temperature vs Gas Composition
%CO
%H2
%CH4
%CO2
Temperature, °F
% Gas
HHV 183 (Btu/scf)
HHV 178 (Btu/scf)
HHV 162 (Btu/scf)
0.25 0.29 0.330.0
5.0
10.0
15.0
20.0
25.0 Equivalence Ratio vs Gas Composition
%CO%H2%CH4%CO2
Equivalence Ratio
% Gas
98 scfm 74 scfm76 scfm
0.25 0.29 0.330
10
20
30
40
50
60
70
80
90 Gas Yield (scf/lb)Cold Gas Efficiency (%)Carbon Conversion Efficiency(%)
Equivalence Ratio
Perc
enta
ge, %
SummaryWith increasing bed temperature:
1. H2 production increases (from 8% to 16%)2. No substantial change in CO production3. Higher Heating Value of product gas increases (from 162 Btu/scf to 183 Btu/scf)
With increasing equivalence ratio:
1. H2 production rate increase because of high bed temperature2. No substantial change in CO and CH4 production rate3. Gas production decreases (from 98 to 74 scfm)4. Cold Gas Efficiency (CGE) increases (from 61% to 72 %) 5. Carbon Conversion Efficiency increase (from 69% to 79%)
Future Goals
Installation of Tar reforming system Steam and Oxygen gasification (Energy
dense syngas) Use of in-bed catalyst to improve syngas
composition Gasification of torrefied biomass Simulation with ASPEN Plus
Acknowledgements
Louisiana Department of Natural Resources
U.S. Department of Energy
CLECO Power, LLC
North Start RMS, LLC
EDG Consulting
Poche-Prouet Associate (Architects)
Thank You for Attending Today’s Presentation
Questions?
Estimated Annual FT Liquids Production
Air Mode, Barrels 515
Oxygen Mode, Barrels 750