Hydrogen and oxygen production by photosynthetic water splitting: Energy and quantum conversion efficiencies

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5199600

Greenbaum, E

Absolute energy and quantum conversion efficiencies based on incident radiation have been measured for five species of green algae. Experiments have been performed with broadband illumination and monochromatic illumination. Maximum efficiencies were obtained in the linear low-intensity portion of the light saturation curve. At these intensities, equivalent solar energy conversion efficiencies of 2-3% were obtained with Chlamydomonas reinhardtil 137C(+). Although this efficiency decreased to less than 0.01% at equivalent incident solar irradiances above 100 w/m)sup)2)), a knowledge of the structure of photosynthetic units and the turnover time of photosynthesis suggest a procedure to overcome this limitation. Using monochromatic illumination at 700 nm, quantum efficiencies were computed from measured energy conversion efficiencies. The maximum measured quantum efficiency for photobiological hydrogen production was 6.3% in the marine species Chlamydomonas D. This value is about 25% of the maximum theoretical value of the quantum efficiency of photobiological hydrogen production. 19 refs., 6 figs.

• Research Organization: Florida Solar Energy Center, Cape Canaveral (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5199600
• Report Number(s): CONF-851006-1; ON: DE88007273
• 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
BIOPHYSICS
BIOSYNTHESIS
CHEMICAL REACTIONS
CHLAMYDOMONAS
ELEMENTS
HYDROGEN
MICROORGANISMS
NONMETALS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
SYNTHESIS
UNICELLULAR ALGAE