What are the Properties of Hydrogen?
Atomic hydrogen (H) is the most abundant chemical element in the universe and – bound in the form of water (H2O) or in the diverse molecules of renewable biomass – also the single most abundant chemical element on planet Earth. Hydrogen naturally joins with itself to form molecular hydrogen (H2) or also called hydrogen gas. Hydrogen gas – with a molecular weight of 2 g/mol – is the lightest gas known to man. Hydrogen gas is not only light but it also has a very low solubility in water, a property which allows its low cost and efficient extraction from aqueous environments, such as a microbe-operated bio-reactor. Only 1.93 ml of hydrogen gas dissolve in 100 ml of water at standard pressure and temperature. Since hydrogen gas is light, it occupies a rather large volume at STP. One gram of hydrogen gas (at 0°C and 1 atm) occupies about 11.13 liters. This feature hampers its easy and cost-effective use as a transportation fuel and rather favors its immediate on-site use in combination with
