Common reed as solid biofuel resource Kronbergs_11.3.2011_Reed... · hemp stalk material. 18....
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Common reed as solid Common reed as solid biofuel biofuel resource resource Ē Ē . . Kronbergs Kronbergs and and A A . . Kronbergs Kronbergs Latvia University of Agriculture Latvia University of Agriculture Faculty of Engineering Faculty of Engineering Institute of Mechanics Institute of Mechanics 11.03.2011.
Transcript of Common reed as solid biofuel resource Kronbergs_11.3.2011_Reed... · hemp stalk material. 18....
Common reed as solid Common reed as solid biofuelbiofuelresourceresource
ĒĒ.. KronbergsKronbergs and and AA.. KronbergsKronbergs
Latvia University of AgricultureLatvia University of AgricultureFaculty of EngineeringFaculty of EngineeringInstitute of MechanicsInstitute of Mechanics
11.03.2011.
Ludzasraj.
Rèzeknes
raj.
Daugavpils
raj.
Krâslavas raj.
Latvian more than 2256 Lakes with sapropel(sediment ) resources
Investigated resources
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Common reeds (Phragmites australis) are overgrowing shorelines of Latvian Lakes –important resource for bioenergy
Phragmites australis
Photo I. Nulle3
The evolution of Lakes and wetlands (Sven Bjork)
Sediments and emergent vegetation transform Lakes to bog ecosystem
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The Lake restoration project – common reed cutting
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The Lake restoration project – common reed root felt cultivation
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Cable operated bucket (6 m3) equipment for sapropel mining. Used also for common reed root felt removal
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Soft container method
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Ecosystem approach let work out innovative mechanisation means in Laboratory of mechanics of LUA and obtain
additional biomass resources
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Ultimate tensile strenght – 330 N/mm2
Ultimate shear strenght – 110 N/mm2
Specific shear cutting energy –0.024 J/mm2
Nip angle – 23 deg
Calorific value – 17 .. 19 MJ/kg
Bulk density – up to 100 kg/m3
Mechanical properties of reed stalks
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Materials testing machine
ZwickTC-FR2.5TN.D09 TestXpert V9.01
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Compacting of common reed particles
Reed particles were compacted in closed die D=35 mm with pressure 212 MPa using hydraulic press equipment 12
Compacting of common reed particles
In compacting the minimum of density 0.87 g cm-3 have briquettes with particle size 12 – 13 mm, but maximum density 1.03 – 1.04 g cm-3 have briquettes of two particle sizes – less than 0.5 mm and size 32 – 33 mm.
< 0.5 mm
12 – 13 mm
32 – 33 mm
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Compacting of common reed particles
Specific pressing energy maximum value (~172 kJ kg-1) has been for reed particle size 32 – 33 mm, but minimum value (~53 kJ kg-1) for particle size less than 0.5 mm 14
Long reed stalk particle 300 mm briguetting and strength testing
Arranged structure of biomass particles in briquetting is increasing durability of briquettes and let obtain density >1000 kg·m-3. Increasing peat proportion in arranged structure reed briquettes till 50% increases splitting force 2 – 3 times. 15
Cutting equipmentCutting equipment
Fig.1. Cutting knives with different geometry Fig.2. Cutting knives
Fig.3. Cutting knive
0.007
0.009
0.011
0.013
0.015
0.017
0 5 10 15 20 25Blade angle, deg
Spac
ific
ener
gy, J
mm
-2
Bevel angle 90ºBevel angle 45ºBevel angle 25º
Fig.4. Specific cutting energy for flattened reed stalks. 16
Cutting properties in dependence on cutter mechanism
Cutting mechanism
№ 1 № 2 № 3 № 4 № 5
τmax,
N mm-2
E,
J mm-2
τmax,
N mm-2
E,
J mm-2
τmax,
N mm-2
E,
J mm-2
τmax,
N mm-2
E,
J mm-2
τmax,
N mm-2
E,
J mm-2
43.6 0.028 24.1 0.024 13.1 0.037 19.0 0.028 16.1 0.052
The cutting knives mechanism № 2 is approved as the most energy efficient.
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Energy crop stalk material cutting energy
Specific cutting energy per mass unit is growing considerably when shredding size is less than 20 mm for common reeds and 35 mm forhemp stalk material. 18
BiomassBiomass shreddershredder
Properties:Properties:
Material Material –– common reedcommon reedKnives thickness Knives thickness –– 8 mm8 mmFraction Fraction –– 1 .. 1 .. 4 cm4 cmShredded reed bulk density Shredded reed bulk density –– 135 kg/m135 kg/m33
Briquette density Briquette density –– 1.04 g/cm1.04 g/cm33
Fig.2. Shredded common reedFig.1. Shredder
Fig.3. Common reed briquette 19
Evaluation of energy crop shredder unification possibilities
Fig.1. Shredder Tuennissen GM-10
Fig.2. Cutting knives and flywheel
The rounding in cutting knives are increasing nip angle.
Increased nip angle improve the biomass shredder technical parameters by reducing rotation speed deviation and wear of cutting and counter knives.
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Thank you for your attention!
Latvia University of AgricultureFaculty of EngineeringInstitute of Mechanics
Prof. Ēriks [email protected]
Andris [email protected]
