Hydrogen from Algae Nanotechnology Solutions . Foothill College Bio-Nano-Info Program. Energy from the Early Earth. Energy Metabolism. Hydrogen Metabolism. H 2 S 2H + S H 2 O H + OH H 2 2 H + 2e - In photosynthesis (simplified): H 2 0 H + OH + 2e -
In photosynthesis (simplified):
Timeline for development of the major life forms.From a course site by Robert Huskey, U. VirginiaLife on Earth
These filaments are believed to be the fossilized imprints of blue-green algae, one of the earliest life forms. They occur in the Bitter Springs Formation in Australia and are about 850 million years old.
Algal cell suspension / cells
Yellow arrow marks insertion of hydrogenase promoter. Right side exp. optimized for continuous H2 production.
Assumptions were made that 10 micro mole of H2 can be produced per hour
(roughly 50% of peak maximum but extended for an hour) per mg of chlorophyll.
Additionally, a density of 10% of the top 1 cm (or 100% of top mm) of the system would be populated by chlorophyll, for a density of 1 mg chlorophyll per square cm of collector.
This leads to 10,000 cm multiplied by 10 mg chlorophyll per centimeter for a total of 100,000 mg chlorophyll. Multiplying 100,000 mg chlorophyll by 10 micromole H2 generated per hour per mg chlorophyll yield 1 mole of hydrogen gas per square meter per hour.
Combusting one mole of H2 with one half mole of oxygen (H2 + ½ O2 H2O) yields 286 KJoules or 68 Kcal. Using any of the following conversions yields KWatt hours or watts from this reaction:
1 calorie = 4.184 Joules
1 calorie = 0.0011622 KwHr
1 Joule = 0.0002778 Watt hours
1 K Joule = 0.2778 watts
286 KJoules X 0.2778 Watts / KJoules = 79 Watts
68,355 calories X 0.0011622 KwHr per calories = 79 KwHr
On first pass, it appears that 1 square meter of hydrogen producing algae (modified for continuous hydrogen production) yields about 79 watts, or enough to run a 75 watt light bulb at full power.
Proton and ion pumps consume
a lot of cellular energy
Nano-channels could be useful
The electrical properties of nanotubes / nanohorns can change, depending on their molecular structure. The "armchair" type has the characteristics of a metal; the "zigzag" type has properties that change depending on the tube diameter—a third have the characteristics of a metal and the rest those of a semiconductor; the "spiral" type has the characteristics of a semiconductor.
Schematic representation of a
composite electrode for low
temperature fuel cells
Schematic representation of themembrane electrode assembly