Indirect gasification for high efficient conversion of high ash coal and lignite

Transcription

1 Indirect gasification for high efficient conversion of high ash coal and lignite Bram van der Drift 20 May 2014, Dresden

2 Torwash Torrefaction ECN DEVELOPMENTS and competences and facilities time [s] FB: Fluidized Bed EF: Entrained Flow PF: Pulverized Fuel FB combustion FB gasification PF combustion EF gasification 0 C 500 C 1000 C 1500 C

3 GASIFICATION principle energy production: fuel + air (l > 1) flue gas + heat 25% energy consumption: fuel + heat gas gasification: fuel + air (l~0.3) gas + 75% 3

4 GASIFICATION indirect gasification: second generation energy production: fuel + air (l > 1) flue gas + heat 25% energy consumption: fuel + heat gas + char/coke + 75% gasification: fuel + air (l~0.3) gas + char/coke 4

5 GASIFICATION indirect gasification: second generation Gas production (pyrolysis and gasification) in reactor 1 Combustion of non-converted carbon with air in reactor 2 Coupled fluidized bed technology: Bed material circulated between reactors Bed material transports char from reactor 1 to reactor 2 Bed material transports energy from reactor 2 to reactor 1 Temperature difference between the reactors typically C Bed material can also e.g. capture S, reduce tar, transport CO 2 (chemical looping) No carbon left No N 2 in syngas 5

6 DEVELOPED for BIOMASS/WASTE gasification/pyrolysis and combustion separated FICFB (TU Vienna)

7 MILENA DEMONSTRATION PLANT 4 MW wood-to-sng plant in Alkmaar (NL)

8 MILENA DEMONSTRATION PLANT 22 MW waste-to-power plant in UK

9 MILENA DEMONSTRATION PLANT 4 MW soya residue-to-power in India

10 Conversion [%] Fuel needed for energy supply CONVERSION vs. TEMPERATURE indirect/direct fluidized bed entrained flow 100% Indirect Fluidized Bed Direct Fluidized Bed Entrained Flow Gasifier ~70% Minimum conversion: unconverted fuel would suffice to supply energy for gasification of biomass tar Volatiles escape (fast) 500 C 1000 C 1500 C

11 INDIRECT GASIFICATION Whereas for normal (direct) gasification, a higher temperature leads to higher conversion For indirect gasification, the temperature can be much lower and yet have full conversion! For biomass and waste, releasing only the volatiles (pyrolysis) is enough, all the remaining fixed carbon energy is needed for energy supply For coals, fixed carbon content is too high and would produce too much energy when combusted, real gasification of part of the carbon is required But full carbon gasification is not required, temperature can be chosen to be relatively low

12 Conversion [%] Fuel needed for energy supply CONVERSION vs. TEMPERATURE indirect/direct fluidized bed entrained flow 100% Indirect Fluidized Bed Direct Fluidized Bed Entrained Flow Gasifier ~60% Minimum conversion: unconverted fuel would suffice to supply energy for gasification of coal Volatiles escape (fast) 500 C 1000 C 1500 C

13 Conversion [%] Fuel needed for energy supply CONVERSION vs. TEMPERATURE indirect/direct fluidized bed entrained flow 100% ~60% Indirect Fluidized Bed 30% gasification is enough to have 100% conversion overall Direct Fluidized Bed Entrained Flow Gasifier Minimum conversion: unconverted fuel would suffice to supply energy for gasification of coal Volatiles escape (fast) 500 C 1000 C 1500 C

14 FROM BIOMASS GASIFIER to COAL GASIFIER

15 THE MILENA FAMILY MILENA (biomass/waste) imilena (coal)

16 imilena RESULTS Tests performed with 5 kg/h lab-scale facility Coals used from India and Turkey Containing over 50% ash Co-financed by EU Optimash project

17 imilena RESULTS imilena high-ash coal CO (vol%) 14.9 H 2 (vol%) 48.3 CO 2 (vol%) 28.5 CH 4 (vol%) 6.0 N 2 (vol%) 2.6 C 2 H y (vol%) 1.3 C 6 H 6 & C 7 H 8 (ppmv) 3200 H 2 S & COS (ppmv) 5000 Tar (g/nm 3 ) 9 Combustor temp. ( C) 889 Gasifier temp. ( C) 853 Bottom ash

18 FINAL REMARKS imilena can produce syngas from high-ash coals (>50% ash) Without the need for an air separation unit At 100% conversion (no carbon in ash) At relatively low temperature: <1000 C Showing high cold gas efficiency: 70% Syngas heating value: >10 MJ/Nm 3 Gas for co-firing, engine, combined cycle, SNG, 30% gasification is enough to have 100% conversion overall Next step: pilot testing (ECN) and demonstration Technology available for licensing Contact us to discuss the options 0.8 MW pilot plant ECN

19 THANKS FOR THE ATTENTION Bram van der Drift ECN Westerduinweg 3 P.O. Box LE Petten 1755 ZG Petten The Netherlands The Netherlands T M vanderdrift@ecn.nl publications: fuel composition database: tar dew point calculator: IEA bioenergy/gasification: Milena indirect gasifier: OLGA: / SNG: / 19