Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Principle of a biological solar energy generator. Energy is collected by micro-algae and converted into biomass. After settlement and cell rupture, which both are not shown in this figure, the biomass is transferred to an anaerobic process. The biogas will be purified (not shown) and methane will be converted to hydrogen and carbon dioxide using steam reforming. Hydrogen will be recovered using membrane separation and delivered to fuel cells, respectively, households. Carbon dioxide will be removed as a fertilizer for the micro-algal process.

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Assessment of economics. The rate of increase of expenses for energy suppliers is given in %.

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Laboratory models of flat PMMA reactors to produce micro-algal biomass. It is possible to simulate daylight using fluorescent tubes (not mounted here), which are under computer control.

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Growth curve of micro-algal biomass monitored by photometry. The absorbance of chlorophyll at 440nm and 680nm has been used as a parameter for cell density.

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Distribution of cell size of micro-algae before and after enrichment using cross-flow ultrafiltration

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: DOC concentration of substrate solution, first stage and second stage of an anaerobic reactor as well as the rate of DOC decomposition. During this experiment, the anaerobic reactor was supplied with micro-algal biomass.

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Loading rate and gas production (refer also to Fig. )

Date of download: 11/2/2017 Copyright © ASME. All rights reserved. From: Combination of Biological Processes and Fuel Cells to Harvest Solar Energy J. Fuel Cell Sci. Technol. 2008;5(3):031001-031001-5. doi:10.1115/1.2889031 Figure Legend: Correlation of carboxylic acids measured by HPLC and IR spectroscopy. The data shown were obtained for the first and second stages of the anaerobic fermentation reactor during successful operation.