References. Results and discussion

Acknowledgment

Conclusions

Results and discussion

The characteristic of syngas from food waste pyrolysis and gasification have been investigated. Food waste is a char-based sample. Results from char-based samples (samples containing volatile matter and char, such as paper [13], cardboard [14,15], woodchips and food waste) follow, qualitatively similar trend. Syngas is characterized by a high flow rate initially, due to pyrolysis, and then followed by a small flow rate which lasts for longer period, which is due to char gasification.

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Gasification yielded enhanced production of syngas, hydrogen and energy as that obtained from pyrolysis. However the time required for gasification is more as compared to pyrolysis. As compared to paper gasification at the same conditions, food waste needed more time to complete the gasification process. Inorganic constituents in food char were found to have a catalytic effect. Char reactivity increased with degree of conversion. In the conversion range from 0.1 to 0.9 the increase in reactivity was accompanied by an increase in pre-exponential factor, suggesting an increase in gasifying agent adsorption rate to char surface. However, in the conversion range from 0.93 to 0.98 the increase in reactivity was accompanied by a decrease in activation energy. A compensation effect was observed in this range of conversion, from 0.93 to 0.98. Isokinetic temperature obtained from Arrhenius plots for X from 0.93 to 0.98 was 1001 ^oC.

This research was supported by the ONR and is support is gratefully acknowledged.

[1] <http://www.landfill-gas.com>.

[2] Tancredi N, Cordero T, Mirasol JR, Juan J. CO2 gasification of eucalyptus wood chars. Fuel 1996;75(13):1505–8.

[3] Montesinos FM, Cordero T, Mirasol JR, Rodriguez JJ. CO2 and steam gasification of a grapefruit skin char. Fuel 2002;81:423–9.

[4] Marsh H, Taylor DA, Lander JR. Kinetic study of gasification by oxygen and carbon dioxide of pure and doped graphitizable carbons of increasing heat treatment temperatures. Carbon 1981;19(5):375–81.

[5] Agrawal RK. On the compensation effect. J Therm Anal 1986;31:73–86.

[6] Dhupe AP, Gokarn AN, Doraiswamy LK. Investigations into the compensation effect at catalytic gasification of active charcoal by carbon dioxide. Fuel 1991;70(7):839–44.

[7] Feistel PP, Van Heek KH, Juntgen H, Pulsifer AH. The compensation effect in the steam gasification of coal. Carbon 1976;14(6):363–4.

[8] Gokarn AN, Muhlen HJ. Catalysis of char gasification by mixed lignosulfonates: quantification of role of each component. Fuel 1996;75(1):96–8.

[9] Li S, Cheng Y. Catalytic gasification of gas–coal char in CO2. Fuel 1995;74(3):456–8.

[10] Meher LC, Sagar DV, Naik SN. Technical aspects of biodiesel production by transesterification-a review. Renew Sust Energy Rev 2006;10:248–68.

[References 11-16 are omitted]

BioMedical Engineering OnLine 2010, 9:84 (http://www.biomedical-engineering-online.com)

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