Rīgas Riga Tehniskā Technical universitāte University Faculty Enerģētikas of Energy un elektrotehnikas and Electrical Engineering fakultāte Vides Institute aizsardzības t of Energy un Systems siltuma and sistēmu Environment institūts www.videszinatne.lv Energy Efficient and Ecological Housing (ECOHOUSING) Quality parameters of biomass fuel Aivars Žandeckis, Ph.D., researcher and lecturer
2 Please name biomass quality parameters Moisture content Gross calorific value Net calorific value Ash content Bulk density, energy density Physical dimensions Other
Moisture content 3 Affects efficiency, emissions, storage durability, NCV, self-ignition, plant design, transportation costs Picture source: Environmental Monitoring laboratory, RTU
4 Moisture content Biomass fuel Moisture content, wt%, d.b. Wood pellets 5.0 8.0 Sawdust 50 Wood logs 10-50 Woodchips 30-50 Straw 15-25 Grass 18 30 Olive residues 50-60 Source: The Handbook of Biomass Combustion and Co-firing
5 When it is better to harvest wood fuels? When it is better to use wood fuels?
Moisture content Natural drying of wood logs (stacked, under cover) 6 Source: Wood Fuels Handbook
Moisture content. Wood log stove 7 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009 Institute of Energy Systems and Environment
8 Is it good to combust very dry wood?
Moisture content. Wood log stove 9 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009 Institute of Energy Systems and Environment
Moisture content. Wood log boiler 10 Fröling FHG Turbo 3000 downdraft combustion, lambda controlled Nominal power: 30 kw Filling volume: 140 l Log length: 50 cm Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009
Moisture content. Wood log boiler 11 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009
Gross calorific value (GCV) The heat released during combustion under the constrains that the water after combustion process is in liquid phase; Affects fuel utilisation, plant design. GCV = 0.3491 X C + 1.1783 X H + 0.1005 X S - 0.0151 X N - 0.1034 X O - 0.0211 X ash [MJ/kg, d.b.] C carbon, wt %, d.b. H hydrogen, wt %, d.b. S sulphur, wt %, d.b. O oxygen, wt %, d.b. Ash ash content, wt%, d.b. Source: English Handbook for Wood Pellet Combustion, 12
Gross calorific value (GCV) 13 Chemical composition of various solid fuels Source: The handbook of Biomass Combustion and Co-firing
Net calorific value (NCV) 14 The heat released during combustion under the constrains that the water after combustion process is in gaseous phase; Affects fuel utilisation, plant design. NCV = GCV (1-w/100) 2.444 w/100-2.444 H/100 8.936 (1-w/100) [MJ/kg, w.b.] GCV gross calorific value, MJ/kg fuel, d.b. w moisture content, wt% (d.b.) H hydrogen, wt%, d.b. Source: English Handbook for Wood Pellet Combustion,
Net calorific value (NCV) 15 NCV as a function of moisture content (for wood) Source: The handbook of Biomass Combustion and Co-firing
Net calorific value (NCV) 16 NCV and energy density Source: The handbook of Biomass Combustion and Co-firing
17 What is annual amount of biomass per land area? Source: The handbook of Biomass Combustion and Co-firing
Ash content Ash forming elements (Si, Ca, Mg, K, Na and P) are present in biomass as salts or as dirt and clay from harvesting and transportation process; Affects Dust emissions, ash removal & utilization, combustion technology 18 Biomass fuel Ash content, wt%, d.b. Bark 5.0 8.0 Woodchips with bark 1.0 2.5 Woodchips without bark 0.8 1.4 Sawdust 05 0.5 11 1.1 Straw and cereals 4.0 12.0 Olive residues 2.0 4.0 Source: The Handbook of Biomass Combustion and Co-firing
Ash melting temperature Affects operation safety, combustion technology, hard deposit formation; 19 Mg, Ca Cl, K, Na; Source: E.Alakangas, CEN Technical Specification for Solid Biofuels
20 Ash melting temperature Biomass fuel Ash melting temperature, ºC Wood 1340-1700 Bark 1220-1453 Miscanthus 1050-1270 Straw 1080-1290 Cereals 1180-1220 Grass 1100-1330 Source: The Handbook of Biomass Combustion and Co-firing
What happens if ash melting temperature t is low? 21 Source: E.Vīgants
Bulk density, energy density 22 Bulk density mass of fuel per unit of volume; Energy density amount of fuel energy in one unit of volume; Affects: fuel logistics (storage, transport, handling). Biomass fuel Bulk density, kg/m 3 Energy density, MJ/m 3 Pellets 600 9840 Sawdust 240 1920 Woodchips 250-450 2800-3900 Grass 200 2740 Bark 320 2620 Straw 120 1740 Source: The Handbook of Biomass Combustion and Co-firing
Bulk end energy density of wood fuels 23 Source: Wood Fuels Handbook
Bulk density, energy density 24 Source: E.Alakangas, CEN Technical Specification for Solid Biofuels
Physical dimensions, form 25 Affects Conveying, combustion technology, bridging, operational safety, drying, emissions Briquettes Pellets Wood logs Source: E.Alakangas, CEN Technical Specification for Solid Biofuels
Physical dimensions, form 26 Chips P16B All <120 mm 100 45 16 8 3,15 <12% Source: E.Alakangas, CEN Technical Specification for Solid Biofuels
Physical dimensions, form 27 Source: Power from Pellets
Physical dimensions. Wood logs 28 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009
Physical dimensions. Wood logs 29 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009
Contacts Riga Technical University Institute of Energy Systems & Environment Kronvalda boul. 1, Riga, Latvia www.videszinatne.lv Aivars Žandeckis aivars.zandeckis@rtu.lv +37167089943