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Title: A new perspective on hydrogen production by photosynthetic water-splitting

Abstract

Present energy systems are heavily dependent on fossil fuels. This will eventually lead to the foreseeable depletion of fossil energy resources and, according to some reports, global climate changes due to the emission of carbon dioxide. In principle, hydrogen production by biophotolysis of water can be an ideal solar energy conversion system for sustainable development of human activities in harmony with the global environment. In photosynthetic hydrogen production research, there are currently two main efforts: (1) Direct photoevolution of hydrogen and oxygen by photosynthetic water splitting using the ferredoxin/hydrogenase pathway; (2) Dark hydrogen production by fermentation of organic reserves such as starch that are generated by photosynthesis during the light period. In this chapter, the advantages and challenges of the two approaches for hydrogen production will be discussed, in relation to a new opportunity brought by our recent discovery of a new photosynthetic water-splitting reaction which, potentially, has twice the energy efficiency of conventional watersplitting via the two light reaction Z-scheme of photosynthesis.

Authors:
;
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
236273
Report Number(s):
CONF-960376-14
ON: DE96010569; TRN: 96:003306
DOE Contract Number:
AC05-96OR22464
Resource Type:
Conference
Resource Relation:
Conference: Spring national meeting of the American Chemical Society (ACS), New Orleans, LA (United States), 24-28 Mar 1996; Other Information: PBD: 1996
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN FUEL; 14 SOLAR ENERGY; 55 BIOLOGY AND MEDICINE, BASIC STUDIES; BIOPHOTOLYSIS; BIOCHEMICAL REACTION KINETICS; PHOTOSYNTHESIS; STARCH; BIOCONVERSION; CARBON DIOXIDE; EFFICIENCY; FERMENTATION; HYDROGEN PRODUCTION

Citation Formats

Lee, J.W., and Greenbaum, E.. A new perspective on hydrogen production by photosynthetic water-splitting. United States: N. p., 1996. Web.
Lee, J.W., & Greenbaum, E.. A new perspective on hydrogen production by photosynthetic water-splitting. United States.
Lee, J.W., and Greenbaum, E.. 1996. "A new perspective on hydrogen production by photosynthetic water-splitting". United States. doi:. https://www.osti.gov/servlets/purl/236273.
@article{osti_236273,
title = {A new perspective on hydrogen production by photosynthetic water-splitting},
author = {Lee, J.W. and Greenbaum, E.},
abstractNote = {Present energy systems are heavily dependent on fossil fuels. This will eventually lead to the foreseeable depletion of fossil energy resources and, according to some reports, global climate changes due to the emission of carbon dioxide. In principle, hydrogen production by biophotolysis of water can be an ideal solar energy conversion system for sustainable development of human activities in harmony with the global environment. In photosynthetic hydrogen production research, there are currently two main efforts: (1) Direct photoevolution of hydrogen and oxygen by photosynthetic water splitting using the ferredoxin/hydrogenase pathway; (2) Dark hydrogen production by fermentation of organic reserves such as starch that are generated by photosynthesis during the light period. In this chapter, the advantages and challenges of the two approaches for hydrogen production will be discussed, in relation to a new opportunity brought by our recent discovery of a new photosynthetic water-splitting reaction which, potentially, has twice the energy efficiency of conventional watersplitting via the two light reaction Z-scheme of photosynthesis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1996,
month = 5
}

Conference:
Other availability
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  • Present energy systems are heavily dependent on fossil fuels. This will eventually lead to the foreseeable depletion of fossil energy resources and according to some reports, an expected global climatic changes due to the emission of carbon dioxide. In principle, hydrogen production by biophotolysis of water can be an ideal solar energy conversion system for sustainable development of human activities in harmony with the global environment. In photosynthetic hydrogen production research, there are currently two main efforts: (1) Direct photoevolution of hydrogen and oxygen by photosynthetic water splitting using the ferredoxin/hydrogenase pathway; (2) Dark hydrogen production by fermentation of organicmore » reserves such as starch that are generated by photosynthesis during the light period. In this presentation, the advantages and challenges of the two approaches for hydrogen production will be discussed, in relation to a new opportunity brought by our recent discovery of a new photosynthetic water-splitting reaction, which, potentially, has twice energy efficiency of conventional water-splitting reaction, via the Z-scheme of photosynthesis.« less
  • Contrary to the prediction of the {open_quotes}Z-scheme{close_quotes} model of photosynthesis, experiments demonstrated that mutants of Chlamydomonas containing Photosystem II (PSII) but lacking Photosystem I (PSI), can grow photoautotrophically with O{sub 2} evolution and using atmospheric CO{sub 2} as the sole carbon source. Autotrophic photosynthesis by PSI-deficient mutants was stable both under anaerobic conditions and in air (21% O{sub 2}) at an actinic intensity of 200 {mu}E/m{sup -2}{sup {sm_bullet}}s. This {open_quotes}PSII photosynthesis,{close_quotes} sufficient to support cell development and mobility, may also occur in wild-type green algae and higher plants. The mutants can survive under 2000 {mu}E{sup {sm_bullet}}m{sup -2}{sup {sm_bullet}}s{sup -1} withmore » air, although they have less resistance to photoinhibition.« less
  • This mission-oriented research project is focused on the production of renewable hydrogen. The authors have demonstrated that certain unicellular green algae are capable of sustained simultaneous photoproduction of hydrogen and oxygen by light-activated photosynthetic water splitting. It is the goal of this project to develop a practical chemical engineering system for the development of an economic process that can be used to produce renewable hydrogen. There are several fundamental problems that need to be solved before the application of this scientific knowledge can be applied to the development a practical process: (I) maximizing net thermodynamic conversion efficiency of light energymore » into hydrogen energy, (2) development of oxygen-sensitive hydrogenase-containing mutants, and (3) development of bioreactors that can be used in a real-world chemical engineering process. The authors are addressing each of these problems here at ORNL and in collaboration with their research colleagues at the National Renewable Energy Laboratory, the University of California, Berkeley, and the University of Hawaii. This year the authors have focused on item 1 above. In particular, they have focused on the question of how many light reactions are required to split water to molecular hydrogen and oxygen.« less
  • 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 atmore » 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.« less
  • Three key advances in photosynthesis research are reported. A significant advance in microalgal water splitting has been made. In the linear, low-intensity region of the light saturation curves, equivalent solar conversion efficiencies of 10% have been measured. A technological advance in the ability to genetically screen individual algal colonies has been made. Successive subcultures of anaerobiosis-stressed Chlamydomonas reinhardtii exhibited enhanced capacity for photoproduction of hydrogen and oxygen.