Solar energy conversion through biophotolysis. Third annual report, April 1, 1978-March 31, 1979

Technical Report · Tue May 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5649680· OSTI ID:5649680

Benemann, J. R.; Murry, M. A.; Hallenbeck, P. C.; Miyamoto, K.; Olafsen, A. G.; Esteva, D. J.; Kochian, L. V.

This report covers the progress during the third year of this project. The state-of-the-art of biophotolysis was reviewed and a bioengineering analysis carried out. The conclusions were that practical biophotolysis systems are feasible; however, they will require, in most cases, relatively long-term R and D. The biophotolysis system developed under this project, utilizing heterocystous blue-green algae, was demonstrated both indoors and outdoors with a model converter system using the heterocystous blue-green alga Anabaena cylindrica. Maximal light energy conversion efficiencies were 2.5% indoors and about 0.2% outdoors, averaged for periods of about two weeks. Achievement of such rates required optimization of N/sub 2/ supply and culture density. A small amount of N/sub 2/ in the argon gas phase used to sparge the cultures was beneficial to the stability of a long-term hydrogen-production activity. A relatively small amount of the hydrogen produced by these cultures can be ascribed to the activity of the reversible hydrogenase which was studied by nitrogenase inactivation through poisoning with tungstate. The regulation of nitrogenase activity in these algae was studied through physiological and immunochemical methods. In particular, the oxygen protection mechanism was examined. Thermophilic blue-green algae have potential for biophotolysis; hydrogen production was studied in the laboratory. Preliminary experiments on the photofermentation of organic substrates to hydrogen was studied with photosynthetic bacteria.

• Research Organization: California Univ., Berkeley (USA). Sanitary Engineering Research Lab.
• OSTI ID: 5649680
• Report Number(s): SAN-0034-239-T1
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080106* -- Hydrogen-- Production-- Biosynthesis & Photochemical Processes
14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ALGAE
BACTERIA
BIOCONVERSION
BIOPHOTOLYSIS
CHEMICAL REACTIONS
CONVERSION
CRYOGENIC FLUIDS
DECOMPOSITION
ELEMENTS
ENERGY CONVERSION
ENZYMES
FEASIBILITY STUDIES
FLUIDS
HYDROGEN COMPOUNDS
HYDROGEN PRODUCTION
HYDROGENASE
MICROORGANISMS
NITROGEN
NITROGENASES
NONMETALS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PHOTOSYNTHETIC BACTERIA
PLANTS
SOLAR ENERGY CONVERSION
SUBSTRATES
WATER