EFFICIENT USE OF BIOMASS FOR ENERGY PRODUCTION

Transcription

1 EFFICIENT USE OF BIOMASS FOR ENERGY PRODUCTION Dr.sc.ing. Edgars Vīgants

2 Content Biomass in Energy sector of Latvia Case study of Ludza biomass project Operational results Actual dilemma Future prospects Conclusions 2

3 Structure of fuel consumption in Latvia 3 Source: Ministry of Economics, 2013

4 Prognosticated fuel consumption in Source: Ministry of Economics, 2013

5 Million EUR/day Export - Import balance of energy sources Fossil fuel Electricity Bio oil Spirits Wood Daily Balance in 2013: Expenses on imported fossils - 17,3 million EUR/day Income from exported energy wood + 3,1 million EUR/day 5 Source: FEI

6 Case study of Ludza biomass project Ludza 6

7 Demo project on GHG reduction Chimney Chimney Diesel oil Flue gas filter Diesel boiler 7 MW Fuel tank Wood chips Wood boiler 8 MW Transport system Wood chips storage with walking floor Open storage for wood chips 7000 m 3 Heat meters Network pumps Heat exchangers 2x8 MW District heating grid 7 Property of Ludza municipality Property of LBE

8 Decrease of heat temperature supplied to DH grid DH system was designed for temperature schedule C (for steam boiler) New temperature schedule of DH system DH water temperature (C) Supply temperature 80 Return temperature Outdoor air temperature (C) Heat losses at DH grid are reduced from 18% to 12 % 8

9 Logistics of Biomass Most of the biomass is delivered from within 50 km radius Moisture content: 35-55% 9

10 Optimization of wood fuel consumption Wood fuel consumption (loose cubic meters for 1 MWh of heat energy) 2,00 1,90 1,80 m3/mwh 1,70 1,60 1,50 1, Period 10

11 Achieved results Positions Initial situation 2000 New situation 2001 Fuel Mazut (heavy oil) Wood fuel, diesel oil Equipment Steam boilers produced in 1967, total capacity 55 t/h New boiler equipment, total capacity 15 MW Efficiency 65 % 83 % Employees 18 8 Heat price 28,57 EUR/MWh 19,53 EUR/MWh Emissions CO t/year SO t/year SO 2 0,5 t/year (440 x) CO t/year (74 x) EUA( )

12 Biomass moisture content 50% 50% Lowest heating value = 2,23 kwh/kg Highest heating value = 2,77 kwh/kg Water Dry biomass 12

13 Air Biomass W d =55% Wet flue gas and dust Drying of biomass Furnace Dryer W d =25% Additional fuel consumption Dry chips bunker To the boiler house 13

14 To dry before or to condense after combustion? n Sources of water vapor in flue gases: Wood biomass moisture, Burning of hydrogen as a part of wood biomass, Water vapor in the air used for combustion. n At the condenser, it is also possible to recover flue gas heat, which at first is cooled down by evaporating sprayed water, and then is condensed together with the initial flue gas moisture. 14

15 Design of flue gas condenser gada 22., 23. februāris, Rīga Enerģētikas politika un klimata aizsardzība Kur atrodamies 20

16 Assembling of condenser 16

17 System monitoring Metering parameters Fuel consumption Oxygen content in flue gas Water flow in condenser circuit Water flow in DH network Water temperature before heat exchanger (condenser circuit) Water temperature after heat exchanger (condenser circuit) Water temperature after heat exchanger (DH network) Water temperature before heat exchanger (DH network) Flue gas temperature after boiler Flue gas temperature before condenser Flue gas temperature after condenser 17

18 Operational data of condenser (average/month during heating season) Parameters Wood boiler heat production, MWh 2780 Condenser heat production, MWh 451 Wood chip consumption, loose.m Condenser efficiency, % 16,2 Wood chip saving, loose.m3 735 Wood chip moisture content, % 47 Wood chip lower heating value, MWh/t 2,39 Wood chip density, t/loose.m3 0,32 Wood chip consumption, MWh 3429 Wood boiler efficiency, % 81,1 Total efficiency, incl. condenser, % 94,2 Specific electricity consumption by the condenser 35 kwh/mwh Achieved results 18

19 Benefits Fuel consumption reduced for 10-20% More power from boiler Reduction of fossil fuel consumption during peak loads Reduction of hard particle emissions by 10 times Strengthened competitiveness 19 Similar condensers can be installed at other boiler houses

20 DH water temperature, 0 C Supply and return temperatures in DH systems Outdoor temperature, 0 C 2th GDH T1 120/70 2th GDH T2 120/70 3th GDH T1 90/60 3th GDH T2 90/60 4th GDH T1 55/25 4th GDH T2 55/25 20

21 Concept of the 4th generation DH 21 H. Lund et al., 4th Generation District Heating (4GDH). Integrating smart thermal grids into future sustainable energy systems/ Energy 68 (2014)

22 Achievements Fuel switch from heavy oil to local biomass Lowered supply temperature for DH grid Optimisation of biomass quality and logistics Design and installation of flue gas condenser Fuel consumptoin reduced by 10-20% Steps towards more efficient use of biomass On the desk Selection of CHP technology: - Biomass gasification and internal combustion engine? - Organic Rankine cycle (ORC) turbine? - Steam turbine? - Stirling engine? Future acfons Energy management Return temperature reduction at DH grid 4th Generation DH 22

23 Conclusions ü There is a considerable potential of biomass for the needs of sustainable energy production in Latvia. ü Heat production from biomass is feasible and costeffective. ü Braking factors: ü Unstable legislation and support mechanisms, ü Lack of available financing, ü Lack of commercialy prooven new technologies for CHP. 23

24 Contacts Edgars Vīgants S. Eizensteina 29, Riga, Latvia, LV-1079 Tel