Biomass resources characterization and biofuels

1

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]

2

CONTENTSCONTENTS

- What is biomass?

- Biomass resources

- Biomass characterization

- Biofuels types

- Solid biofuels pellets

Biomass resources characterization and biofuels

3

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.

4

Photosynthesis

5

Renewable energy source

Climate neutral

6

structural components

50%

40 %

ethanol

polymers of sugars

7

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:

8

Forest Wood Residues

Forest Residues

The primary forestry residues include:

logging residues from conventional

harvest operations, forest

management and land cleaning.

9

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

10

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

11

From farms and animal processing operations

Complex source of organic materials, environmental consequences

anaerobic biodigestion

Animal Wastes

Agricultural Residues

BIOGAS

bacteria

biological process

12

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

14

Sorghum


Product:

OILY CROPS

Rapeseed,

sunflower, soybean

biodiesel

Energy crops

Rapeseed

SUGAR CROPS

Sorghum, sugar

cane, sugar-beetbioethanol

15

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


Country DM yield [t/ha.year]

The Netherlands

4 - 9

U.K. 5 - 12 Italy 5 - 22 Greece 15 - 24

16



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:

17


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

18

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

19

Woody Energy crops


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.

20

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

21

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

22

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.

23

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.

24

. Heating value


High heating value (HHV)

Low heating value (LHV)

energy that is available from burning a substance

Value used

25

.

Low heating value


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

26

Volume (m³) required to substitute one cubic meter of oil by some other fuels


1 thermal MW

store a volume of 6.000 cubic meter of coal

store 36.000 cubic meter, which means a quantity six more

27

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 %


proximate analysis

28

Chemical composition

ultimate analysis

C 35-50 %

H 6- 6,5 %

O 38-42 %

N 0,1-0,5 %

S 0,05 %


ultimate analysis

H2O

CO2

NO2

SO2

ash

Combustion

29


30

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.


31

Ash

Source: Biomass Resource Assessment and Utilization Options for Three Counties in Eastern Oregon Oregon Department of Energy December 2003


32

Moisture content is an important characteristic affecting the quality of biomass fuel for thermal processes like combustion, gasification and pyrolysis.

Moisture


33

Moisture: influence design plant, direct cost factor, influence the price of fuel.

Moisture


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

34

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

35

Biomass energy chains

36

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

37

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

38

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

39

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

40

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

41

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

42

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

43

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

44

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

45


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

46

GOODBYE

Claudia Bassano

[email protected]


Documents

Biomass resources characterization and biofuels