biomass resources characterization and biofuels
DESCRIPTION
Biomass resources characterization and biofuels. CLAUDIA BASSANO Renewable Sources and Innovative Energetic Cycles C.R. CASACCIA – Via Anguillarese, 301 TEL. + 39 06 30484042 00060 S. MARIA DI GALERIA FAX +39 06 30486486 ROMA E-Mail: [email protected]. CONTENTS. - PowerPoint PPT PresentationTRANSCRIPT
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Biomass resources Biomass resources characterizationcharacterization and biofuels and biofuels
CLAUDIA BASSANO
Renewable Sources and Innovative Energetic Cycles
C.R. CASACCIA – Via Anguillarese, 301 TEL. + 39 06 30484042
00060 S. MARIA DI GALERIA FAX +39 06 30486486
ROMA E-Mail: [email protected]
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CONTENTSCONTENTS
- What is biomass?
- Biomass resources
- Biomass characterization
- Biofuels types
- Solid biofuels pellets
Biomass resources characterization and biofuels
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What is biomass?
Any organic matter whic is available on a renewable or recurring basis, including agricultural crops and trees, wood and wood residues, plants (including aquatic plants), grasses, animal residues, municipal residues.
Biomass is produced from water and CO2 by photosynthesis.
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Photosynthesis
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Renewable energy source
Climate neutral
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structural components
50%
40 %
ethanol
polymers of sugars
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Forest residueForest residueMill wasteMill wasteUrban wood wasteUrban wood waste
Corn StoverCorn StoverRice hullsRice hullsSugarcane bagasseSugarcane bagasseAnimal Animal biosolids
Hybrid poplarHybrid poplarSwitchgrassSwitchgrassWillowWillow
Forest Wood Residues Agricultural Residues Energy Crops
Biomass ResourcesBiomass Resources
Fonte:
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Forest Wood Residues
Forest Residues
The primary forestry residues include:
logging residues from conventional
harvest operations, forest
management and land cleaning.
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Secondary forestry residues
mill wastes
pulping liquors.
Tertiary forest residues :
construction and demolition debris,
unusable pallets,
tree trimmings from the urban environment
Mill Waste
Urban wood waste
Forest Wood Residues
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Agriculture crop residues include stalks and leaves, not harvested or removed from the fields.
Examples include :corn stover, wheat straw, rice straw, soybeans straw, sugarcane
Agricultural Residues
agricultural tree crops (vineyards, olive and fruit groves)
Animal residues
Agro-industrial residues of food processing industry
Waste stream: rice husks, molasses & bagasse, residues from palm oil mills
corn
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From farms and animal processing operations
Complex source of organic materials, environmental consequences
anaerobic biodigestion
Animal Wastes
Agricultural Residues
BIOGAS
bacteria
biological process
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Energy crops
Crops used for energy purposes
Herbaceous
Annual
Rapeseed, Sunflower, Beet, Sorghum
Perennials
Miscanthus, Cardoon ecc.
Short Rotation Forestry
Woody
Cardoon
13Sorghum
Herbaceous Energy crops
Herbaceous energy crops are:
annual (cut annually and re-sown each year)
perennials
Switchgrass
Energy crops
RapeseedCardoon
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Sorghum
Herbaceous Energy crops
Product:
OILY CROPS
Rapeseed,
sunflower, soybean
biodiesel
Energy crops
Rapeseed
SUGAR CROPS
Sorghum, sugar
cane, sugar-beetbioethanol
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Herbaceous Energy crops yields Yield is the quantity of biomass you can have from one hectare of landThe choice of the appropriate location is the most important factor driving the biomass yields of the grasses
SwitchgrassSwitchgrass yields by region
Country DM yield [t/ha.year]
Denmark 5- 15
Germany 4- 30
U.K. 10 - 15
Switzerland 13 - 19
Austria 22
Spain 14 - 34
Greece 26 - 44
Italy 30 – 32
MiscanthusMiscanthus yields by region
Herbaceous Energy crops
Country DM yield [t/ha.year]
The Netherlands
4 - 9
U.K. 5 - 12 Italy 5 - 22 Greece 15 - 24
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Herbaceous Energy crops
Herbaceous Energy crops
their high biomass yield potential
the concentration of the yield in one harvest,
and delayed harvest is possible
their persistence and yield stability
their efficient use of resources and low input
demand
the benefits of their rhizome systems.
Miscanthus and switchgrass are particularly interesting for the following reasons:
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Short Rotation Forestry
Short rotation forestry (SRF) are selected, fast-growing, tree species, such as willow, poplar and eucalyptus
Harvested within 3 to 10 years of planting.
Trees are planted very densely
Poplar 6-12000 per haWillows 10-12,000 per ha
Energy crops
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Woody Energy crops
Species Willow Poplar Robinia
Part of Europe Scandinavia, British Islands
Central Europe
Mediterranean Europe
Crop density plant/ha 18-25,000 10-15,000 8-12,000
Rotation years 3-4 1-3 2-4
Av. butt diameter at harvest (mm)
15-30 20-50 20-40
Av height at harvest (m) 3.5-5.0 2.5-7.5 2.0-5.0
Moisture content (% weight)
50-55 50-55 40-45
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Woody Energy crops
Short Rotation Forestry
Yeld range Dry matter Energy
content GJ/t
Crops Fresh matter
t/ha % t/ha Willow 40 10-15 18.7 Poplar 55 10-15 17.3 Fiber sorghum
50-100 25-40 20-30 16.7-16.9
Sweet sorghum
50-100 25-35 12-25 16.7-16.9
Miscanthus 40-70 35-45 15-30 17.6-17.7 Cardoon 25-35 40-45 10-15 15.5-16.8
Sources: McKendry (2002); Venturi, Piero and Venturi, Gianpietro (2003). Analysis of energy comparison for crops in European agricultural systems. Biomass and Bioenergy, 25, 235 – 255.
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Environmental benefits
Marginal land recovery
protecting the land (improve soil quality)
erosion control
less fertilizer, pesticide, herbicide, and fungicide than annual row crops
to purify polluted soils. (phytoremediation)
sequestration of CO2;
Energy crops benefits
Economical benefits
income benefits for farmers
positive effects on local employment in rural areas for the biomass resource production
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bioenergy activity requires very deep knowledge of wide sectoral competence
High level of mechanization
Water, soil, climatic, environmental constraints limiting the biomass productivity and the type of plants
Energy crops are less competitive
future: higher yields at lower costs
Need to adopt horizontal and vertical integration of sub-systems to improve the economic basis of bioenergy complexes
Energy crops disadvantages
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The development of SRF for renewable energy production is a new sector with potential for considerable expansion, offering benefits for growers, developers, consumers, local communities and the environment.
Research are focused on increase yield productivity
Energy crops
Future expansion of the biomass power market
The SRF represent one of the point on the future expansion of the biomass power market.
biomass power market require the development of a feedstock supply system based on large-scale and sure production of biomass fuel.
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Biomass characterization
Characteristics affecting the properties of wood as a fuel:
heating value,
chemical composition,
moisture content,
density,
hardness,
the amount of volatile matters,
the amount of solid carbon,
ash
The biomass forms the basis of any Bioenergy application and often the physic, chemical characteristics of the fuel also define the type of technology to be used.
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. Heating value
Biomass characterization
High heating value (HHV)
Low heating value (LHV)
energy that is available from burning a substance
Value used
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.
Low heating value
Biomass characterization
Fuel
Energy density by
mass GJ/tonne
Energy density by
mass kWh/kg
Bulk density kg/m3
Energy density by
volume MJ/m3
Energy density by
volume kWh/m3
Wood chips (Very dependent on MC)
7-15 2-4 175-350 2000-3600 600-1000
Log wood (stacked - air dry: 20% MC)
15 4.2 300-550 4500-8300 1300-2300
Wood (solid - oven dry) 18-21 5-5.8 450-800 8100-16800 2300-4600
Wood pellets 18 5 600-700 10800-12600 3000-3500
Miscanthus (bale) 17 4.7 120-160 2000-2700 560-750
Coal (lignite to anthracite) 20-30 5.6-8.3 800-1100 16000-33000 4500-9100
Oil 42 11.7 870 36,500 10200
Natural gas (NTP) 54 15 0.7 39 10.8
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Volume (m³) required to substitute one cubic meter of oil by some other fuels
Biomass characterization
1 thermal MW
store a volume of 6.000 cubic meter of coal
store 36.000 cubic meter, which means a quantity six more
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Chemical composition
DRY MATTER WATER
ASH 0,4-0,6 %of dm weight
SOLID CARBON
11,4-20 % of dm weight
VOLATILE MATTER
84-88 % of dm weight
Average moisture content of the total weight
Bark, Saw dust 55-60 %
Forest chips 40 %
Wood pellets 8-12 %
Biomass characterization
proximate analysis
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Chemical composition
ultimate analysis
C 35-50 %
H 6- 6,5 %
O 38-42 %
N 0,1-0,5 %
S 0,05 %
Biomass characterization
ultimate analysis
H2O
CO2
NO2
SO2
ash
Combustion
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Biomass characterization
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The ash composition and the ash melting behaviour should be taken into consideration to avoid slagging problems in boiler.
Ash
The melting behaviour of straw and energy crops (Miscanthus) is in a range of 600- 950°C
Normal wood do not start melting before 1100°C.
Biomass characterization
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Ash
Source: Biomass Resource Assessment and Utilization Options for Three Counties in Eastern Oregon Oregon Department of Energy December 2003
Biomass characterization
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Moisture content is an important characteristic affecting the quality of biomass fuel for thermal processes like combustion, gasification and pyrolysis.
Moisture
Biomass characterization
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Moisture: influence design plant, direct cost factor, influence the price of fuel.
Moisture
Biomass characterization
the more water fuel contains then lower heating value then fuel efficiency is lower
the more water fuel contains then bigger boiler volume needed -then more expensive boiler
In combustion processes, high moisture content can lead to incomplete combustion, low thermal efficiency, low flame temperatures, excessive emissions and the formation of tars that could cause slagging problems.
lower moisture content cost less to transport and can reduce the size of handling, processing and energy conversion equipment
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Main biomass energy chains :
Wood energy chain
the use of dry products (cellulosic crops and residues) for thermo-chemical conversion (combustion, gasification, pyrolysis);
Liquid biofuel chain
the use of crops (oilseed rape, sunflower, sugar beet, cereals etc.) for liquid biofuel production;
Ethanol (sugar crops)
Biodiesel (oil crops)
Biogas
the use of wet products for anaerobic digestion.
Biomass energy chains
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Biomass energy chains
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Biofuels types
Solid biofuel
Chips
Pellets
briquettes
Liquid biofuel
biodiesel bioethanol
Fuel produced directly or indirectly from biomass or from their processing and conversion derivatives
Biomass low energy density transport problem expensive
Biofuels
transport
Electricity and heat
production
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increase the energetic value
to lower the volume for storage
to facilitate the handling, transportation and to lower its
costs
to increase the energy density to volume ratio
to eliminate the loss of material caused to fermentation
Main advantages of biofuels:
Biofuels
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wood chips
chipped woody biomass has the form of pieces with a defined particle size produced by mechanical treatment
typical length 3-5 cm
Moisture 30-40 %
Density 200-300 kg/m3
LHV 10-13,4 MJ/kg 3-3,6 kWh/kg 750 kWh/m3
Cost 40- 80 €/t
Biofuels chips
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pellet
Wood pellets are densified wood fuels which have been produced from sawdust, grinding dust, shavings, bark, herbaceous biomass, fruit biomass, or biomass blends and mixtures. etc.
Biofuels pellets
typical length 5 to 30 mm
Moisture 8-12 %
Density 650-700 kg/m3
LHV 17 MJ/kg 4,7 kWh/kg 3080 kWh/m3
Cost 150-200 €/t
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Pellet storing
Pellet cooling
Source :Refined Bio-Fuels Pellets and Briquettes Characteristics, uses and recent innovative production technologies
The pellets production
Storing and pretreatment
Drying the raw material
pellet production process
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The pellets production
3. Pellets extruded to the outside of the die
1. raw materials are fed into pellet cavity
2. Rotation of die and roller pressure forces materials through die, compressing them into pellets
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Advantages of wood fuel:
Less volume
Fewer deliveries
Consistent size and moisture content
Less ash and emissions
Pellets are dry and can be stored
without degrading
The pellets advantages
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The pellets disadvantages
Disadvantages of wood fuel:
Need large storage place
Ashes
More expensive
Advantages of wood fuel:
Flow like a liquid
Easier to handle
Easier to ignite
Pellets stove
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1 kg of chips whit moisture 40 % LHW=10,46 MJ/kg is equivalent :
0,28 litre oil (LHWoil =10,19 kWh/ litre)
0,3 m3 CH4 (PCI CH4 =9,5 kWh/Nm3)
1 kg of pellet LHW=16,92 MJ/kg is equivalent :
0,46 litre oil
0,49 m3 of CH4
Confront
Chips process simpler and cheaper
Chips lower energy density, lower volumetric bulk density, more storage space
Biofuels chips and pellets
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Biomass resources Biomass resources characterizationcharacterization and biofuels and biofuels
Conclusion
Biomass has different origines
Low energy density biofuels, transport problem
Energy crops : future expansion of the biomass power market.
Pellets solid biofuel: expansion market in Europe
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GOODBYE
Claudia Bassano
Biomass resources Biomass resources characterizationcharacterization and biofuels and biofuels