Cultivation of macroscopic marine algae

Technical Report · Mon Nov 01 00:00:00 EST 1982

DOI:https://doi.org/10.2172/6592012· OSTI ID:6592012

Ryther, J H

The red alga Gracilaria tikvahiae may be grown outdoors year-round in central Florida with yields averaging 35.5 g dry wt/m/sup 2/.day, greater than the most productive terrestrial plants. This occurs only when the plants are in a suspended culture, with vigorous aeration and an exchange of 25 or more culture volumes of enriched seawater per day, which is not cost-effective. A culture system was designed in which Gracilaria, stocked at a density of 2 kg wet wt/m/sup 2/, grows to double its biomass in one to two weeks; it is then harvested to its starting density, and anaerobically digested to methane. The biomass is soaked for 6 hours in the digester residue, storing enough nutrients for two weeks' growth in unenriched seawater. The methane is combusted for energy and the waste gas is fed to the culture to provide mixing and CO/sub 2/, eliminating the need for aeration and seawater exchange. The green alga Ulva lactuca, unlike Gracilaria, uses bicarbonate as a photosynthesis carbon source, and can grow at high pH, with little or no free CO/sub 2/. It can therefore produce higher yields than Gracilaria in low water exchange conditions. It is also more efficiently converted to methane than is Gracilaria, but cannot tolerate Florida's summer temperatures so cannot be grown year-round. Attempts are being made to locate or produce a high-temperature tolerant strain.

• Research Organization: Univ. of Florida, Gainesville, FL (United States)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 6592012
• Report Number(s): SERI/STR-231-1820; ON: DE83004696
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
ALGAE
CULTIVATION
ACID CARBONATES
AERATION
BIOMASS PLANTATIONS
CARBON DIOXIDE
FLORIDA
METHANE
PLANT GROWTH
SEAWATER
SEAWEEDS
YIELDS
ALKANES
AQUATIC ORGANISMS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
FEDERAL REGION IV
GROWTH
HYDROCARBONS
HYDROGEN COMPOUNDS
NORTH AMERICA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
USA
WATER
AQUATIC SPECIES PROGRAM
STIMULATION
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)