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REVTECH Torrefaction Technologyfor all kind of biomass (wood, fruit pip, cereal waste…)
Outlines
• Torrefaction of biomass, why ?
• The REVE technology
• Application for biomass torrefaction
– Wood chips
– Fruit pips
– Other type
• Conclusion: the main advantages
Torrefaction : the origins
• Biomass – important potential of advanced fuels
– Great availability, wide range of possibilities
– Available at low cost
– Sustainable and environmentally friendly
• The challenges:
– Make the biomass more uniform
– Densify the energy (reduce transport costs)
– Make it easier to store (no deterioration even in tropical climate)
• How ?
Pelletizing / Torrefaction
Pelletization: biomass densification
(Nielsen et al., 2009, Wood and Fiber Science 41 (4): 414-425)
transport cost and handling
Today : the only solid biofuel with a global market
Biomass densification :0.2-0.3 g/cm3 to 0.65-0.75 g/cm3
(Shang et al., 2012, Fuel Processing Technology 101: 23-28)
(Tumuluru et al., 2011, Biofuels Bioprod. Biorefinering 5: 683-707)
But:
(Peng et al., 2013, Fuel)
Moisture uptake
long storage and transport
grinding cost
Fine particles needed
Pelletization: biomass densification
(Nielsen et al., 2009, Wood and Fiber Science 41 (4): 414-425)
transport cost and handling
Today : the only solid biofuel with a global market
Biomass densification :0.2-0.3 g/cm3 to 0.65-0.75 g/cm3
(Shang et al., 2012, Fuel Processing Technology 101: 23-28)
(Tumuluru et al., 2011, Biofuels Bioprod. Biorefinering 5: 683-707)
But:
Moisture uptake
long storage and transport
grinding cost
Fine particles needed
Torrefaction
Heat the product to 200-300°C for 10 – 60mn
In low O2 environment
Torrefaction : Why ? How ?
« Status overview of torrefaction technologies » IEA Bioenergy Task 32 Report, December 2012:
The challenges of torrefaction:
• Only a few technologies can handle a large spectrum of particle sizes
• High quantity of gas to be treated (heat carrying medium)
• Screw reactors, drum reactors or belt conveyors: limited scaleabilitymultiple production lines
(Stelte et al., 2013, Biomass and Bioenergy 49: 214-221)
Pelletization of torrefied strawCombination of torrefaction and pelletization :
High density Water-resistant
Solid biofuel:
Post- or pre-torrefaction ?
Feedstock, grinding cost, … Existing plant or not ?
Torrefaction degree?
Revtech Heat Treatment Technology
• Principle of operation
• Experience in food industry
• Scale up possibilities
The Company
• Created in 1997.
• Basis : Vibrating Electrical Heated Tube.
• Design and fabrication of equipment for continuous heat treatment devices of bulk solids in food, pharmaceutical and chemical industry.
• Installation and commissioning of complete customized industrial units in the customers plant:
Tailor – made & turn – key project.
• Pasteurization of herbs & spices
• Pasteurization & Roasting of nuts
• Heat treatment of grain products
• Heat treatment for chemical industry, environment…
Main domains of activity
How does it work?
Continuous Process
Combinations of 3 simple principles:
• Transportation / Mixing by vibrations
• Heating by direct contact with a hot surface
• Treatment in a confined atmosphere
Principle of operation
In terms of process:(from the product point of view)
40 to 180 m long
3’’ to 10’’
T from 50 to 400°C
Main parameters
• Flowrate: 100 kg/h to 5 ton/h
• Temperature: 50 to 400°C
• Residence time: 1 to 40 mn
• Atmosphere: air, steam, nitrogen…
Electrical current Optional injection of gas (steam, N2,…)
Hot Product
Treated Productat ambient
temperature
Raw Product
Cooler
Tube at 80 to 300°C
for 5 to 20 mn
Principle of operation
1. Transport / Mixing: in ss tube vibrated by off balanced motors
Principle of operation
Off balanced motors
1. Transport / Mixing: in ss tube vibrated by off balanced motors
Principle of operation
• Frequency: ~ 12 Hz• Amplitude: ~ 4 mm• Acceleration: ~ 4 g
2. Heating of the product: by direct contact with hot ss pipe which is
heated by electricity using Joule effect (High impedance tube)
• High current
• Low voltage < 40V
Electrical current
Principle of operation
3. Operation in controlled atmosphere:
• Product is heated in a confined atmosphere
• Gas can be injected through the process
• Gas sucking is possible as well
Principle of operation
The main operating parameters are then:
• temperature (+/- 1°C) – with 2 or 3 independent heating zones
• residence time
• atmosphere inside the tube
• flowrate of product
Principle of operation
Principle of operation
Example of a 5 ton/h roaster Example of a 1 ton/h roaster
Example of a 2 ton/h roaster
Example of a 300 kg/h roaster
Example of applications in food industry
• Cereals can be processed very well
• Even fine particles like wheat flour can be processed
Wheat flour – 220°C , 0 – 3 – 6 – 9 – 15 – 30 mn
Roasted barley: 240°C , 0 – 5 – 10 – 15 – 20 – 25 – 30 – 35 mn
Revtech for biomass torrefaction
• Feasibility on various biomasses
• Effect on facilitating grinding
• Effect on moisture intake
Torrefaction of various biomass
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Wood chips 11.8 0.28 5-20 85
Pine barks 59.7 0.33 10-40 95
Olive pips 20.3 0.66 5 140
Straw 11.0 0.05 20-100 10
Torrefaction of olive pips
EU BC&E 2013 22
6’ 12’ 18’ 24’ 30’Raw
260°C
280°C
• Initial humidity around 20 %• Power consumption: around 250 kW.h / ton
Torrefaction of wood chips
3’45 7’30 15’ 22’30 30’Raw
260°C
280°C
300°C
• Initial humidity around 12 %• Power consumption: around 150 – 200 kW.h / ton
WSED next Biomass 2014 24
Effect on grinding
Results on particle distribution using a blade grinder:
WSED next Biomass 2014 25
Effect on Energy Densification
T (°C) t (min) YS (% ar) HHV (MJ/kg) η (%) dη
260 30 74.2 20.31 89.4 1.20
280 30 64.3 21.07 80.4 1.25
300 15 59.4 22.06 77.7 1.31
300 30 50.8 22.78 68.6 1.35
Conditions: Runs at 85 kg/h (H = 12 %) (HHV: 19.12 MJ/kg)
Mass yield Heating value Energy yield Energy densification
Ideal for pellets production
Ideal for co firing / gasification
WSED next Biomass 2014 26
Torrefaction of pine pellets
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 0
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
WSED next Biomass 2014 27
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 30 s
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
Torrefaction of pine pellets
WSED next Biomass 2014 28
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 1 min
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
Torrefaction of pine pellets
WSED next Biomass 2014 29
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 2 min
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
Torrefaction of pine pellets
WSED next Biomass 2014 30
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 3 min
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
Torrefaction of pine pellets
WSED next Biomass 2014 31
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 4 min
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
Torrefaction of pine pellets
WSED next Biomass 2014 32
Biomass Moisture (%) Density (g/cm3) Particule size (mm) Mass flowrate (kg/h)
Pellets Din+ < 8 > 0.65 6 x 30 200
t = 8 min
9’ - 260°C6’ - 280°C
Raw
3’ - 260°C3’ - 280°C
15’ - 260°C9’ - 280°C
21’ - 260°C12’ - 280°C
27’ - 280°C
Moisture uptake test
15 min at 260°C or 9 min at 280°C are sufficient
YS ≈ 75% & η ≈ 90%
Torrefaction of pine pellets
Conclusions
• Various kind of biomass have been successfully torrefied in the REVTECH: Raw biomasses : wood chips, barks, olive pips, straw Pellets
• Pellets : low torrefaction degree is sufficient (YS≈75% and η≈ 90%)
• REVTECH integration: • Energy efficiency : 80-90% 250 kW.h/ton• Simple and compact unit• Versatile : pre- or post-pelletisation / all particle size / very homogeneous
Next steps:
Gas treatment: energy recovery
Heat integration: drying step, …