Biomass production, anaerobic digestion, and nutrient recycling of small benthic or floating seaweeds
A number of experiments have been carried out supporting the development of a seaweed-based ocean energy farm. Beginning in 1976, forty-two species of seaweed indigenous to the coastal waters of Central Florida were screened for high biomass yields in intensive culture. Gracilaria tikvahiae achieved the highest annual yield of 34.8 g dry wt/m/sup 2/ day. Yield has been found to vary inversely with seawater exchange rate, apparently because of carbon dioxide limitation at low exchange rates. Gracilaria was anaerobically digested in 120 liter and 2 liter reactors. Gas yields in the large digesters averaged 0.4 1/g volatile solids (.24 1 CH/sub 4//gv.s.) with a bioconversion efficiency of 48%. Studies of the suitability of digester residue as a nutrient source for growing Gracilaria have been conducted. Nitrogen recycling efficiency from harvested plant through liquid digestion residue to harvested plant approached 75%. Studies of nutrient uptake and storage by Gracilaria, Ascophyllum, and Sargassum showed that nutrient starved plants are capable of rapidly assimilating and storing inorganic nutrients which may be used later for growth when no nutrients are present in the medium. A shallow water seaweed farm was proposed which would produce methane from harvested seaweed and use digester residues as a concentrated source of nutrients for periodic fertilizations.
- Research Organization:
- Solar Energy Research Inst., Golden, CO (USA); Woods Hole Oceanographic Institution, MA (USA)
- DOE Contract Number:
- AC02-77CH00178
- OSTI ID:
- 5489547
- Report Number(s):
- SERI/TR-98133-1B; ON: DE82009172
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SEAWEEDS
ANAEROBIC DIGESTION
NUTRIENTS
PRODUCTIVITY
BIOMASS PLANTATIONS
FERTILIZERS
FLORIDA
METHANE
PLANT GROWTH
PRODUCTION
RESIDUES
ALKANES
AQUATIC ORGANISMS
BIOCONVERSION
DIGESTION
FEDERAL REGION IV
GROWTH
HYDROCARBONS
MANAGEMENT
NORTH AMERICA
ORGANIC COMPOUNDS
PLANTS
PROCESSING
USA
WASTE MANAGEMENT
WASTE PROCESSING
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)