Energy Efficient and Ecological Housing (ECOHOUSING)

Transcription

1 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 Energy Efficient and Ecological Housing (ECOHOUSING) Quality parameters of biomass fuel Aivars Žandeckis, Ph.D., researcher and lecturer

2 2 Please name biomass quality parameters Moisture content Gross calorific value Net calorific value Ash content Bulk density, energy density Physical dimensions Other

3 Moisture content 3 Affects efficiency, emissions, storage durability, NCV, self-ignition, plant design, transportation costs Picture source: Environmental Monitoring laboratory, RTU

4 4 Moisture content Biomass fuel Moisture content, wt%, d.b. Wood pellets Sawdust 50 Wood logs Woodchips Straw Grass Olive residues Source: The Handbook of Biomass Combustion and Co-firing

5 5 When it is better to harvest wood fuels? When it is better to use wood fuels?

6 Moisture content Natural drying of wood logs (stacked, under cover) 6 Source: Wood Fuels Handbook

7 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 8 Is it good to combust very dry wood?

9 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

10 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

11 Moisture content. Wood log boiler 11 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009

12 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 = X C X H X S X N X O 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

13 Gross calorific value (GCV) 13 Chemical composition of various solid fuels Source: The handbook of Biomass Combustion and Co-firing

14 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) w/ H/ (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,

15 Net calorific value (NCV) 15 NCV as a function of moisture content (for wood) Source: The handbook of Biomass Combustion and Co-firing

16 Net calorific value (NCV) 16 NCV and energy density Source: The handbook of Biomass Combustion and Co-firing

17 17 What is annual amount of biomass per land area? Source: The handbook of Biomass Combustion and Co-firing

18 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 Woodchips with bark Woodchips without bark Sawdust Straw and cereals Olive residues Source: The Handbook of Biomass Combustion and Co-firing

19 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 20 Ash melting temperature Biomass fuel Ash melting temperature, ºC Wood Bark Miscanthus Straw Cereals Grass Source: The Handbook of Biomass Combustion and Co-firing

21 What happens if ash melting temperature t is low? 21 Source: E.Vīgants

22 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 Sawdust Woodchips Grass Bark Straw Source: The Handbook of Biomass Combustion and Co-firing

23 Bulk end energy density of wood fuels 23 Source: Wood Fuels Handbook

24 Bulk density, energy density 24 Source: E.Alakangas, CEN Technical Specification for Solid Biofuels

25 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

26 Physical dimensions, form 26 Chips P16B All <120 mm ,15 <12% Source: E.Alakangas, CEN Technical Specification for Solid Biofuels

27 Physical dimensions, form 27 Source: Power from Pellets

28 Physical dimensions. Wood logs 28 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009

29 Physical dimensions. Wood logs 29 Source: H.Hartmann, P.Turovski, Technology and Support Centre of Renewable Raw Materials, Straubing, Germany, 2009

30 Contacts Riga Technical University Institute of Energy Systems & Environment Kronvalda boul. 1, Riga, Latvia Aivars Žandeckis