Hydrogen production by photosynthesis

Conference · Thu Jan 01 00:00:00 EST 1981

OSTI ID:6660456

Greenbaum, E

The photoevolution of hydrogen and oxygen by photosynthesis is an approach to the problem of solar energy conversion. This presentation is concerned with the roles of Photosystem II and the electron transport chain of photosynthesis in providing reducing equivalents which are eventually evolved as molecular hydrogen. Experimental data are presented on two systems which are capable of simultaneous photoproduction of molecular hydrogen and oxyen. The first is a green algal system. The second is a non-living cell-free system comprised of isolated chloroplasts, ferredoxin, and hydrogenase. Experiments have been performed which suggest that both the reducing side of Photosystem II as well as endogenous reductants R (interacting directly with the electron transport chain) can provide electrons which are evolved as molecular hydrogen. These data suggest that the photochemical machinery of photosynthesis can be used to perform true photosynthetic water splitting, i.e., 2H/sub 2/O ..-->.. 2H/sub 2//sup +/O/sub 2/. The first experiments were performed on the CFH system using the technique of single turnover saturating flashes of light. This is a powerful method for studying the kinetic and mechanistic aspects of photoreactions. The preliminary results with this technique suggest that the turnover kinetics of the CFH system are relatively fast and comparable to that of normal photosynthesis. However, it appears that the number of functional photosynthetic units is relatively low as determined by the standard Emerson and Arnold Unit for normal photosynthesis.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6660456
• Report Number(s): CONF-810116-1
• Resource Relation: Conference: 5. annual IGT meeting on energy from biomass and wastes, Lake Buena Vista, FL, USA, 26 Jan 1981
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
08 HYDROGEN
ALGAE
HYDROGEN PRODUCTION
CHLOROPLASTS
BIOPHOTOLYSIS
FERREDOXIN
HYDROGEN
HYDROGENASES
OXYGEN
PHOTOSYNTHESIS
WATER
BIOCONVERSION
CELL CONSTITUENTS
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
ENZYMES
HYDROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PLANTS
PROTEINS
SYNTHESIS
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)
080106 - Hydrogen- Production- Biosynthesis & Photochemical Processes