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 CO 2 by photosynthesis.
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
13 Sorghum Herbaceous Energy crops Herbaceous energy crops are: annual (cut annually and re-sown each year) perennials Switchgrass Energy crops Rapeseed Cardoon
15 Herbaceous Energy crops yields Yield is the quantity of biomass you can have from one hectare of land The choice of the appropriate location is the most important factor driving the biomass yields of the grasses Switchgrass Switchgrass yields by region Miscanthus Miscanthus yields by region Herbaceous Energy crops
16 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:
17 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 ha Willows 10-12,000 per ha Energy crops
19 Woody Energy crops Short Rotation Forestry 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 Biomass characterization High heating value (HHV) Low heating value (LHV) energy that is available from burning a substance Value used
26 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
27 Chemical composition DRY MATTERWATER 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
28 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 H 2 O CO 2 NO 2 SO 2 ash Combustion
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. Biomass characterization
31 Ash Source: Biomass Resource Assessment and Utilization Options for Three Counties in Eastern Oregon Oregon Department of Energy December 2003 Biomass characterization
32 Moisture content is an important characteristic affecting the quality of biomass fuel for thermal processes like combustion, gasification and pyrolysis. Moisture Biomass characterization
33 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
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
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 length3-5 cm Moisture30-40 % Density200-300 kg/m 3 LHV10-13,4 MJ/kg 3-3,6 kWh/kg 750 kWh/m 3 Cost40- 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 length5 to 30 mm Moisture8-12 % Density650-700 kg/m 3 LHV17 MJ/kg 4,7 kWh/kg 3080 kWh/m3 Cost150-200 €/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 (LHW oil =10,19 kWh/ litre) 0,3 m 3 CH 4 (PCI CH4 =9,5 kWh/Nm 3 ) 1 kg of pellet LHW=16,92 MJ/kg is equivalent : 0,46 litre oil 0,49 m 3 of CH 4 Confront Chips process simpler and cheaper Chips lower energy density, lower volumetric bulk density, more storage space Biofuels chips and pellets
45 Biomass resources characterization 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