To main content
Norsk
Publications

H-2 production from marine and freshwater species of green algae during sulfur deprivation and considerations for bioreactor design

Academic article
Year of publication
2008
Journal
International Journal of Hydrogen Energy
External websites
Cristin
Doi
Contributors
Kari Skjånes, Gjert Knutsen, Torsten Källqvist, Peter Lindblad

Summary

Twenty-one species of green algae isolated from marine, freshwater and terrestrial environments were screened for the ability to produce H-2 under anaerobic conditions. Seven strains found positive for H-2 production under anaerobic conditions were also screened for the ability to produce H-2 under sulfur (S) deprivation. In addition to the traditional model species Chlamydomonas reinhardtii, C. noctigama (freshwater) and C. euryale (brackish water) were able to produce significant amounts of H-2 under S-deprivation. These species were also able to utilize acetate as a substrate for growth in light. The S-deprivation experiments were performed under photoheterotrophic conditions in a purpose-specific designed bioreactor, and it was shown that an automated pH adjustment feature was essential to maintain a stable pH in the cultures. Several materials commonly used in bioreactors, such as rubber materials, plastics and steel alloys, had a negative effect on the survival of S-deprived algae cultures. Unexpectedly, traces of H-2 were produced under S-deprivation during O-2 saturation in the cultures, possibly derived from local anaerobic environments formed in algal biofilms on the membranes covering the O-2 electrodes.