Clean Energy Under our Feet?

Peter Coy writing in the New York Times explores the possibility of extensive natural deposits of hydrogen gas, the ultimate clean fuel.  The possibility of natural hydrogen deposits has long been discussed by scientists.  Mendeleev, the inventor of the periodic table, wrote about it in 1888, but serious exploration for such deposits has not occurred.  Commercial exploration of geological deposits have gasses and liquids have centered on petroleum and natural gas.  Hydrogen would not be expected to be found together with those fossil fuels.  Hydrogen can also be difficult to detect.  That seems to be changing.  

Coy sites a recent article in Science which asks "does Earth hold vast stores of a renewable, carbon-free fuel?" There have been observations of "natural hydrogen" in many places, but it has not led to development.  A big break came in 2012, as noted in the Science article.  A businessman in Mali hired a Canadian firm to analyze the gas flowing from a hole drilled on his property.  It turned out to be 98% hydrogen.  The gas has been put to use running a generator for a nearby village.  Contrary to the usual case for fossil fuels the gas flow has not diminished and continues to provide energy for the community.  This turns out to be expected from the chemistry that produces the hydrogen.  At depths where the temperatures are high and iron (Fe) concentrations are significant and moisture(H2O) is present the following hydrogen (H2) producing chemistry occurs:

Earth's Internal Structure

This chemistry provides a continuous source of hydrogen.  If that hydrogen is trapped in appropriate geological structures it could be tapped to provide a continuous source of clean carbon-free fuel.  

Coy makes it clear that finding and using reserves of "natural" hydrogen is not without challenges.  His report makes good case, however that the possibilities are quite promising.  His report discusses chemistry in an accurate and accessible way.  He treats the science optimistically but realistically.  Overall the report gives a good sense of an exciting scientific development with possible far-reaching ramifications.