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