| 摘要 |
PURPOSE:To generate hydrogen, by cultivating a green alga capable of evolving hydrogen under light and aerobic conditions in water to carry out photosynthesis, followed by cultivating it under dark and slightly aerobic conditions in water so that the substance accumulated by the photosynthesis is decomposed. CONSTITUTION:A green alga such as Chlamydomonas reinhardtii, etc. capable of producing hydrogen is cultivated under light and aerobic conditions in water. In the cultivation, a mixed gas of carbon dioxide and air in a volume ratio of (2:98)-(10:90) is introduced into water, and photosynthesis is carried out. It is then cultivated under dark and slightly aerobic conditions, so that the substance having undergone photosynthesis during the cultivation under light and aerobic conditions and accumulated is decomposed to generate hydrogen. The cultivation under dark and slightly aerobic conditions starts in the presence of <=0.3vol% oxygen in a gaseous phase, and is carried out in a nitrogen atmosphere containing a very small amount of oxygen. The cultivation in the light and dark cycle is done at 15-40 deg.C, and day and night cycle is used as the light and dark cycle. |
