Advertisement

Biomass Conversion and Biorefinery

, Volume 2, Issue 1, pp 1–10 | Cite as

Simulation of biomass gasification in a dual fluidized bed gasifier

  • Jie He
  • Kristina Göransson
  • Ulf Söderlind
  • Wennan Zhang
Original Article

Abstract

Biomass gasification with steam in a dual-fluidized bed gasifier (DFBG) was simulated with ASPEN Plus. From the model, the yield and composition of the syngas and the contents of tar and char can be calculated. The model has been evaluated against the experimental results measured on a 150 KWth Mid Sweden University (MIUN) DFBG. The model predicts that the content of char transferred from the gasifier to the combustor decreases from 22.5 wt.% of the dry and ash-free biomass at gasification temperature 750°C to 11.5 wt.% at 950°C, but is insensitive to the mass ratio of steam to biomass (S/B). The H2 concentration is higher than that of CO under the normal DFBG operation conditions, but they will change positions when the gasification temperature is too high above about 950°C, or the S/B ratio is too low under about 0.15. The biomass moisture content is a key parameter for a DFBG to be operated and maintained at a high gasification temperature. The model suggests that the gasification temperature is difficult to be kept above 850°C when the biomass moisture content is higher than 15.0 wt.%. Thus, a certain amount of biomass needs to be added in the combustor to provide sufficient heat for biomass devolatilization and steam reforming. Tar content in the syngas can also be predicted from the model, which shows a decreasing trend of the tar with the gasification temperature and the S/B ratio. The tar content in the syngas decreases significantly with gasification residence time which is a key parameter.

Keywords

Biomass Gasification Simulation Tar 

Nomenclature

daf

Dry and ash free

LHV

Lower-heating value, MJ/Nm3

ag, k, m, n, x, y

Constants

R

The gas constant

Qcg

Heat carried by bed material, KW

S/B

The mass ratio of steam to biomass

M

Mass flow, kg/s

P

Pressure, atm

T

Temperature, °C

τ

Gasification residence time, s

Bed porosity

Km

The maximum value of the mass transfer coefficient, m/s

\( fv_{\text{char}}^c,\;fv_{\text{char}}^i \)

(Current and initial) char flow, kg/s

dp

Biomass/char particle diameter, m

[6 × (1 − ∊)]/\( d_p^c \)

Particle density number, 1/m

Mi, Mc

Moisture content, wt. %

C

Concentration, mol/m3

\( C_{\text{ash}}^{\text{wp}} \)

Ash content, wt. %

\( C_{\text{char}}^w,\;C_{\text{tar}}^w \)

Concentration, kg/kg biomassdaf

\( {r_{\text{char}}},\;{r_{\text{tar}}} \)

Reaction rate, mol·m−3·s−1

Notes

Acknowledgments

The author would like to acknowledge the project support of EU regional structure fund, Ångpanneföreningen Foundation for Research and Development, LKAB, Västernorrland Länsstyrelsen, FOKUSERA, Härnösand Kommun, Toyato, SCA BioNorr and SUNTIB.

References

  1. 1.
    Zhang W (2010) Automotive fuels from biomass via gasification. Fuel Process Technol 91(8):866–876. doi: 10.1016/j.fuproc.2009.07.010 CrossRefGoogle Scholar
  2. 2.
  3. 3.
    Sotudeh-Gharebaagh R, Legros R, Chaouki J, Paris J (1998) Simulation of circulating fluidized bed reactors using ASPEN PLUS. Fuel 77(4):327–337. doi: 10.1016/s0016-2361(97)00211-1 CrossRefGoogle Scholar
  4. 4.
    Lee JM, Kim YJ, Lee WJ, Kim SD (1998) Coal–gasification kinetics derived from pyrolysis in a fluidized-bed reactor. Energy 23(6):475–488. doi: 10.1016/s0360-5442(98)00011-5 CrossRefGoogle Scholar
  5. 5.
    Nikoo MB, Mahinpey N (2008) Simulation of biomass gasification in fluidized bed reactor using ASPEN PLUS. Biomass Bioenerg 32(12):1245–1254. doi: 10.1016/j.biombioe.2008.02.020 CrossRefGoogle Scholar
  6. 6.
    Doherty W, Reynolds A, Kennedy D (2009) The effect of air preheating in a biomass CFB gasifier using ASPEN Plus simulation. Biomass Bioenerg 33(9):1158–1167. doi: 10.1016/j.biombioe.2009.05.004 CrossRefGoogle Scholar
  7. 7.
    Corella J, Sanz A (2005) Modeling circulating fluidized bed biomass gasifiers. A pseudo-rigorous model for stationary state. Fuel Process Technol 86(9):1021–1053. doi: 10.1016/j.fuproc.2004.11.013 CrossRefGoogle Scholar
  8. 8.
    Göransson K, Söderlind U, Zhang W (2011) Experimental test on a novel dual fluidised bed biomass gasifier for synthetic fuel production. Fuel 90(4):1340–1349. doi: 10.1016/j.fuel.2010.12.035 CrossRefGoogle Scholar
  9. 9.
    Göransson K, Söderlind U, He J, Zhang W (2011) Review of syngas production via biomass DFBGs. Renew Sust Energ Rev 15(1):482–492. doi: 10.1016/j.rser.2010.09.032 CrossRefGoogle Scholar
  10. 10.
    Fercher E, Hofbauer H, Fleck T, Rauch R, Veronik G (1998) Two years experience with the FICFB--gasification process. 10th European Conference and Technology Exhibition on Biomass for Energy and Industry:280–283Google Scholar
  11. 11.
    Hofbauer H, Veronik G, Fleck T, Rauch R, Mackinger H, Fercher E (1997) The FICFB gasification process. Dev thermochem biomass convers 2:1016–1025Google Scholar
  12. 12.
    Pfeifer C, Rauch R, Hofbauer H (2004) In-bed catalytic tar reduction in a dual fluidized bed biomass steam gasifier. Ind Eng Chem Res 43(7):1634–1640. doi: 10.1021/ie030742b CrossRefGoogle Scholar
  13. 13.
    Heyne S (2010) Process integration opportunities for synthetic natural gas (SNG) production by thermal gasification of biomass. Dissertation, Chalmers University of Technology, GöteborgGoogle Scholar
  14. 14.
    Seemann M, Thunman H (2009) The new Chalmers research-gasifier. In: Yue G, Zhang H, Zhao C, Luo Z (eds) Proceedings of the 20th International Conference on Fluidized Bed Combustion, Xi'an. Tsinghua University Press, pp 659–663Google Scholar
  15. 15.
    Brown JW (2006) Biomass gasification: fast internal circulating fluidised bed gasifier characterisation and comparison. Dissertation, University of Canterbury, CanterburyGoogle Scholar
  16. 16.
    Foscolo, PU (2007) Biomass: a sustainable energy source. Paper presented at the ICTP Experts Meeting on “Science and Renewable Energy”, Trieste, January 15–18, 2007Google Scholar
  17. 17.
    van der Meijden CM, Bergman PCA, van der Drift A, Vreugdenhil BJ (2010) Preparations for a 10 MWth Bio-CHP Demonstration Based on the Milena Gasification Technology. Paper presented at the 18th European Biomass Conference and Exhibition, Lyon, May 3–7, 2010Google Scholar
  18. 18.
    Tar removal from low-temperature gasifiers (2010) ECN Petten. http://www.ecn.nl/docs/library/report/2010/e10008.pdf. Accessed April 2010
  19. 19.
    Paisley MA, Corley RN, Dayton DC (2007) Advanced biomass gasification for the economical production of biopower, fuels, and hydrogen—implementation in Montgomery, New York. Paper presented at the 15th Biomass Conference and Exhibition, Berlin, May 7–11, 2007Google Scholar
  20. 20.
    Affordable, low-carbon diesel fuel from domestic coal and biomass (2009) US Department of Energy, National Energy Technology Laboratory. http://www.netl.doe.gov/energy-analyses/pubs/CBTL%20Final%20Report.pdf. Accessed 14 Jan 2009
  21. 21.
    Dowaki K (2011) Energy Paths due to Blue Tower Process. In: Bernardes MAdS (ed) Biofuel’s engineering process technology. InTech, Rijeka, pp 585–610Google Scholar
  22. 22.
    Fagbemi L, Khezami L, Capart R (2001) Pyrolysis products from different biomasses: application to the thermal cracking of tar. Appl Energ 69(4):293–306. doi: 10.1016/s0306-2619(01)00013-7 CrossRefGoogle Scholar
  23. 23.
    Primary measures to reduce tar formation in fluidised-bed biomass gasifiers (2004) ECN, Energy Research Centre of the Netherlands. http://www.ecn.nl/docs/library/report/2004/c04014.pdf. Accessed March 2004
  24. 24.
    Idaho National Laboratory (INL) (2007) Economic and technical assessment of wood biomass fuel gasification for industrial gas production. http://www.inl.gov/technicalpublications/Documents/3787330.pdf. Accessed September 2007
  25. 25.
    Bergman PCA, van Paasen SVB, Boerrigter H (2003) The novel “OLGA” technology for complete tar removal from biomass producer gas. Paper presented at the Pyrolysis and Gasification of Biomass and Waste, Expert Meeting, Strasbourg, 30 September–1 October 2002Google Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Jie He
    • 1
  • Kristina Göransson
    • 1
  • Ulf Söderlind
    • 1
  • Wennan Zhang
    • 2
  1. 1.Department of Natural Sciences, Engineering and MathematicsMid Sweden UniversityHärnösandSweden
  2. 2.Department of Natural Sciences, Engineering and MathematicsMid Sweden UniversitySundsvallSweden

Personalised recommendations