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Title: Maximizing the Hydrogen Photoproduction Yields in Chlamydomonas Reinhardtii Cultures: The Effect of the H2 Partial Pressure

Maximizing the Hydrogen Photoproduction Yields in Chlamydomonas Reinhardtii Cultures: The Effect of the H2 Partial Pressure Photoproduction of H{sub 2} gas has been examined in sulfur/phosphorus-deprived Chalmydomonas reinhardtii cultures, placed in photobioreactors (PhBRs) with different gas phase to liquid phase ratios (V{sub g.p.}/V{sub l.p.}). The results demonstrate that an increase in the ratio stimulates H{sub 2} photoproduction activity in both algal suspension cultures and in algae entrapped in thin alginate films. In suspension cultures, a 4x increase (from {approx}0.5 to {approx}2) in V{sub g.p.}/V{sub l.p} results in a 2x increase (from 10.8 to 23.1 mmol l{sup -1} or 264-565 ml l{sup -1}) in the total yield of H{sub 2} gas. Remarkably, 565 ml of H{sub 2} gas per liter of the suspension culture is the highest yield ever reported for a wild-type strain in a time period of less than 190 h. In immobilized algae, where diffusion of H{sub 2} from the medium to the PhBR gas phase is not affected by mixing, the maximum rate and yield of H{sub 2} photoproduction occur in PhBRs with V{sub g.p.}/V{sub l.p} above 7 or in a PhBR with smaller headspace, if the H{sub 2} is effectively removed from the medium by continuous flushing of the headspace with argon. These experiments in combination with studies of the direct inhibitory more » effect of high H{sub 2} concentrations in the PhBR headspace on H{sub 2} photoproduction activity in algal cultures clearly show that H{sub 2} photoproduction in algae depends significantly on the partial pressure of H{sub 2} (not O{sub 2} as previously thought) in the PhBR gas phase. « less
Authors: ; ; ; ; ;
Publication Date:
OSTI Identifier:OSTI ID: 1050101
DOE Contract Number:AC36-08GO28308
Resource Type:Journal Article
Resource Relation:Journal Name: International Journal of Hydrogen Energy; Journal Volume: 37; Journal Issue: 10
Research Org:National Renewable Energy Laboratory (NREL), Golden, CO.
Sponsoring Org:USDOE Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell Technologies Program
Country of Publication:United States
Language:English
Subject: 08 HYDROGEN; 59 BASIC BIOLOGICAL SCIENCES; ALGAE; ALGINATES; ARGON; CHLAMYDOMONAS; DIFFUSION; HYDROGEN; PARTIAL PRESSURE; PHOTOPRODUCTION; STRAINS Chemical and Biosciences; Energy Sciences