A document discusses the adaptation of a patented biomass-digesting process, denoted sequential batch anaerobic composting (SEBAC), to recycling of wastes aboard a spacecraft. In SEBAC, high-solids-content biomass wastes are converted into methane, carbon dioxide, and compost.

SEBAC includes three stages: For stage 1, biomass is placed in a vessel, wherein it is fermented and serves as a leachbed. Stage 1 is started by recycling, from stage 3, of leachate, which wets the bed and inoculates it with microorganisms. After stage 1 has been started, it becomes Stage 2, during which leachate is recycled to keep the bed moist. Stage 2 becomes stage 3 when its leachate is used to start a new stage 1. Leachate is conveyed through the leachbeds by gravity and is conveyed between stages by pumping or gravity, and the beds are not flooded. The spacecraft version of SEBAC incorporates modifications to reduce the sizes of reactors and enable operation in microgravity. The modifications include flooding of the leachbeds, pumping to eliminate reliance on gravity, the use of external liquid/gas separators, and densification of biomass in the leachbeds.

This work was done by David P. Chynoweth, Arthur A. Teixeira, John M. Owens, and Patrick J. Haley of the University of Florida for Johnson Space Center. For further information, contact the JSC Innovation Partnerships Office at (281) 483-3809.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

University of Florida
Environmental Systems
Commercial Space Technology Center
AP Black Hall
P.O. Box 116450
Gainesville FL 32611-6450
Phone No.: (352) 392-7814
Fax No.: (352) 392-3673

Refer to MSC-23815-1, volume and number of this NASA Tech Briefs issue, and the page number.

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This article first appeared in the April, 2009 issue of NASA Tech Briefs Magazine.

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