Wednesday, 2 November 2005 - 1:45 PM
371d

Deflagration Behavior during Ignition of the Flash CarbonizationTm Process

Samuel R. Wade, Teppei Nunoura, and Michael J. Antal. Hawaii Natural Energy Institute, University of Hawaii, Manoa, 1680 East West Road, POST 109, Honolulu, HI 96822

Flash CarbonizationTM is a novel process in which biomass is converted to bio-carbon (i.e. charcoal) quickly and efficiently. To begin this process a canister containing a packed bed of feedstock is placed within a pressure vessel. The system is charged to an initial pressure of approximately 10-20 bar using compressed air. An electric heater is used to ignite a flash fire within the bed. After two minutes additional air delivery is initiated, the flame propagates through the bed, and the biomass is converted to a high-yield bio-carbon.

In lab-scale tests some fuels have been observed to ignite violently within the initial two minutes. The result is a sudden drastic pressure rise (ΔP~10 bar within 1-2 seconds). Because this event could potentially be hazardous, a study of this phenomenon was undertaken in preparation for a scale-up of the Flash CarbonizationTM process to a commercial sized demonstration reactor. The influence of initial pressure, feed moisture content, and ignition heater power were examined by following a 23 full factorial experimental design approach. The results of this study—which indicate that a safe scale-up of the process is achievable—will be presented.


See more of #371 - Reactor Engineering for Biomass Feedstocks (T7005)
See more of Topical 7 - Envisioning Biorefineries

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