torrefaction of agricultural and …...torrefaction of agricultural and forestry feedstocks in a...
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TORREFACTION OF AGRICULTURAL AND FORESTRYFEEDSTOCKS IN A PILOT SCALE FACILITY:COMPARISON OF MASS AND ENERGY BALANCEST. Melkior, M. Perez, S. Thiéry, P. Ponsdevincent,A. Chatroux, M. Gonzalez Martinez, C. Dupont
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Biomass torrefaction
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
200– 300°C
P(atm)10min– 1h
Inert atmosphere
§ ↑heating value
§ hydrophobic
§ ↑flowability
§ ↑grindability
§ usesRaw biomass
Torrefiedsolid
Gaseous products
§ harmful fortheprocess
§ chemicals (added value)
↓transportcost
Energy
Chemicals
Materials
~70%mass
Permanentgases (CO,CO2)
Volatilespecies (furans,ketones,phenols)
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Biomass torrefaction upscaling
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Mobile Flip WP 2.4. Torrefaction Mobile Flip WP 3à Next presentation
This presentationàPresentation 242 and poster 534
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Objectives
÷Studying biomass torrefaction behavior in large-scale tests:• Biomass conveying• Mass balances• Energy balances
÷Large-scale production of torrefied biomasses for testing new applicationsof the torrefied products:
• Pelletizing à presentation 445 -298
• Soil amendment à presentation 442
• Particle boards manufacturing à oral flash/poster 480
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
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Génépi research facility
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Grinding
Torrefaction
Gasification
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Centorré torrefaction oven
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
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Centorré torrefaction oven
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Feedinghopper
(dry biomass)
Natural gasCH4
O2
N2
Gas topost-combustion
Outlet flowto the container
.
Air cooler
Multiple-hearth torrefactionfurnace
- Temperature: 200-350°C
- Mass flow: 50-150 kg/h
- Atmospheric pressure
- Feedstock: chips or pellets:
wood, agricultural residues,non-hazardous waste
- Moisture < 10 % (after drying)
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Centorré torrefaction oven
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Centorré scheme oftheoven
Rabbling system
Centorré (2soils) Post-combustion
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Composition of the products
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
÷Solid product: mass loss ajusted by:• Temperature• Residence time (related to the speed of rotation of the oven)
÷Gaseous products:
• Gases include He (tracer gas) and combustion-derived gases from the burners (H2O, CO2 and residual CH4)
• Water (~ 80% of the total condensable species)
• Dry condensables (cold trap + GC/FID):
• Dry permanent gases (µ-GC):
• N2: 80%
• CO2: 10%
• CO: 2-3%
• O2: 2-3 %
• Traces of H2, CH4, C2H4,
C2H6, C3H8 and H2.
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Materials tested and operating conditions
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Wheat strawBeech Poplar
250°C, 75 minutes
Ope
ratin
gco
nditi
ons
250°C, 75 minutes
250°C, 90 minutes
280°C, 30 minutes
280°C, 60 minutes
250°C, 20 minutes
250°C, 60 minutes
15 mm: 250°C, 75 min
15 mm: 260°C, 45 min
30 mm: 250°C, 75 min
Corn cob
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Biomass conveying
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Poplar250°C, 90 minutes
Wheat straw250°C, 20 minutes
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Mass and energy balances
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
CENTORRE
Flow rateCHO contents
LHV
Gas analysis: N2, CO2, CO, O2, CH4He content => gas flow rateCondensables: trapping and analysis
Torrefiedbiomass
Gas andvolatiles
At each level: gas and floortemperature
flow ratewater contentC, H, O contentsLHV
Gas flow rates
Depression into the oven
Gas flow rate
Biomass
Air + natural gas
Air entries (leaks)
He
N2 sweeping
Air entries (biomass)
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Mass balance: example for beech
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
CENTORRE
Biomass
Air + natural gas
Air entries
He
Torrefied biomass Gas + volatile species
136 - 168 kg/hWater content: 9 - 7 %
100 - 129 kg/hMass loss: 20%db
N2 sweeping2.4 Nm3/h
0.15 Nm3/h
3.3 - 3.8 Nm3/h31 - 35 Nm3/h
12.4 Nm3/h
Air entries (biomass)0.2 - 0.3 Nm3/h
0.5 kg / Nm3 (db)Water content: 80%m
(dry gases)51 - 57 Nm3/h
250°C, 75 min
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Energy balance
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
T
Resid
ence
time
Wat
erco
nten
t
Inle
tmas
sflo
w
Inle
tdry
biom
ass
Inle
tWat
er
Wat
erhe
atin
g
Wat
erev
apor
atin
g
Stea
mh
eatin
g
Solid
heat
ing
Tota
lre
quire
d
Net
natu
ral
gas
cons
umpt
ion
Net
ener
gysu
pplie
d
Biomass °C tmin %db kg/h Kg/h Kg/h MJ/h MJ/h MJ/h MJ/h MJ/h Nm3/h MJ/h
Poplar chips
250 75 4.5% 156 149 7 2.3 15.8 2.1 44.5 65 1.63 67
250 90 3.0% 158 153 5 1.6 10.7 1.4 45.8 60 1.04 43
280 30 4.0% 129 124 5 1.7 11.6 1.9 41.9 57 1.46 60
280 60 4.5% 127 121 6 1.9 12.9 2.1 41.0 58 1.81 74
Corn cob 30mm 250 75 8.0% 171 157 14 4.6 30.9 4.1 47.0 87 1.47 60
Corn cob 15mm250 75 8.0% 180 166 14 4.8 32.5 4.3 49.5 91 2.1 86
260 45 8.0% 183 168 15 4.9 33.0 4.7 52.5 95
Beech chips 250 75 9.40% 136 123 13 4.3 28.9 3.8 36.8 74 1.4 57
Wheat straw 250 20 10.0% 95 86 10 3.2 21.4 2.9 25.6 53 1.1 45
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Conclusions
÷Large-scale production of torrefied biomasses succesful÷Comparison of biomass conveying (woody/agricultural biomasses)÷Difficulties in wheat straw conveying
÷Final mass loss of the torrefied biomasses:÷Adjusted through operating coniditions÷Depedent on biomass properties (composition, moisture)
÷Preliminary study for mobile unit design
GONZALEZ MARTINEZ MaríaTorrefaction of agricultural and forestry feedstocks in a pilot scale facility: comparison of mass and energy balances
Perspectives
÷Torrefaction tests on sunflower seed shells÷Improving biomass conveying
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