Torrefaction of Oil Palm Empty Fruit Bunch (EFB) briquettes

- Bemgba Bevan Nyakuma -

IGCESH 2014- Johor Bahru, Malaysia -

Co-authors

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Anwar Johari, Arshad Ahmad, Tuan Amran Tuan Abdullah, Syie Luing Wong.

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Outline

What is Biomass Torrefaction?

Why is Torrefaction important?

How can Torrefaction be carried out?

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• Mild pyrolysis thermal pre-treatment 200-300°C oxygen deficient environment.

• Drying, Devolatization, Depolymerisation.• Removes H2O and CO2

• Properties of Torrefied biomass temperature, time & biomass type.

What is Biomass Torrefaction?

Importance of Torrefaction?

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• Mass loss hemicellulose decomposition

• Improves heating value & energy density

• Structure modification brittleless or grindability

Weight Loss during Torrefaction of Wood

Importance of Torrefaction?

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• Decrease in mass, devolatization depolymerisation

• O/C & H/C ratios.

• Higher heating value (HHV), Energy density

Van Krevelen Diagram

Importance of Torrefaction?

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• Increased C & reduced O content reduces thermodynamic losses

• Reduced moisture pelletization & densification handling & transport

• Reduces hygroscopicity long term storage

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• Colour changes in torrefied biomass • Carbon & Fixed Carbon

content

• Examples of Torrefaction• roasting of coffee beans, • low temp production of

biochar

Colour changes during Torrefaction of Palm waste

Importance of Torrefaction?

How can Torrefaction be carried out?

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How can Torrefaction be carried out?

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• Size Reduction Torrefaction Pelletization

• Pelletization biomass pre-treatment technique

• Improves biomass fuel properties mass-heat transfer

How can Torrefaction be carried out?

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• Our method proposed reversing the process;

• Pelletization Torrefaction Size Reduction

• Why normal procedure inefficient, costly, & time consuming

Methodology

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Experimental set up for oil palm EFB Briquette Torrefaction.

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Results & Discussion?

Temperature (°C )

Mass of Torrefied EFB Briquette (g)

Mass Yield (g)

Mass Yield (%)

220 9.02 0.90 90.20250 7.44 0.74 74.40275 6.25 0.63 62.50300 4.22 0.42 42.20

Effect of Torrefaction Temperature of oil palm EFB Briquettes.

• Mass yield decreased from 90.20 - 42.20 % with increasing temperature

• Due to drying, partial devolatization & hemicellulose depolymerisation

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Any Results?

• Colour gradually changed from greyish brown to black.

• Increase in carbon & fixed carbon content partial devolatization and decomposition of hemicellulose.

(a) Raw feedstock; (b) 220 °C (c) 250 °C (d) 275 °C (e) 300 °C.

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Results…

Time (min)

Mass of Torrefied EFB Briquette (g)

Mass Yield(g)

Mass Yield (%)

15.00 9.33 0.93 93.3030.00 7.89 0.79 78.9060.00 4.22 0.42 42.20

Effect of Residence Time on Torrefaction of oil palm EFB Briquettes

• Mass yield 93.3 % to 42.20 %.

• Ym at t = 15 mins is drying mass yield moisture content.

• Ym at t =30, 60 mins devolatization & hemicellulose decomp.

carbon & fixed carbon content.

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Conclusion

• Temperature and residence time significantly mass yield of oil palm EFB Briquettes during torrefaction.

• Optimal mass yield of oil palm EFB briquettes torrefaction can be achieved at 300 °C @ t = 60 mins.

• Torrefaction of pelletized palm waste showed higher mass yield than previously reported.

Thank you

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References

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• Uemura, Y., Omar, W.N., Tsutsui, T., & Yusup, S.B. Torrefaction of oil palm wastes. Fuel, 90 (8), (2011), 2585-2591.

• Prins, M.J., Ptasinski, K.J., & Janssen, F.J. More efficient biomass gasification via torrefaction. Energy, 31(15), (2006), 3458-3470.

• Uemura, Y., Omar, W., Othman, N. A., Yusup, S., & Tsutsui, T. Torrefaction of oil palm EFB in the presence of oxygen. Fuel, 103, (2013), 156-160.

• Basu, P. Biomass gasification and pyrolysis: practical design and theory. Academic press (2010).• Bridgeman, T.G., Jones, J.M., Shield, I., & Williams, P.T. Torrefaction of reed canary grass,

wheat straw and willow to enhance solid fuel qualities and combustion properties. Fuel, 87(6), (2008) 844-856.

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