Saturday, April 30, 2011

Deep Oil From Diamonds.

According to a new computer model, liquid methane in contact with a partially hydrogen-terminated diamond surface at extremely high pressures and temperatures spontaneously forms longer hydrocarbons, and hence the material of crude oil could be formed deep in the earth. Geologists, certainly in the West, believe that 99% or more of the hydrocarbons present in crude oil and natural gas originate from the "cooking" over millennia of the dead remains of living organisms (biotic), buried under layers of sediments 5-10 miles deep in the Earth's crust. However, the abiotic theory of petroleum generation found force in Russia and Ukraine, proposed by such greats as Dmitri Mendeleev (who devised the Periodic Table the classifies the chemical elements), Alexander von Humboldt and Marcellin Berthelot.

The authors of the present study ( do not claim to have proved a case for abiotic oil, but they note that hydrocarbons could be formed by purely mineral means in particular geological environments such as rifts and subduction zones where the temperatures and pressures are "right", i.e. 1,500 K and 50,000 times the pressure at the surface of the Earth. The calculations indicate that the formation of longer chain hydrocarbons can happen in pure methane but the process is accelerated when the methane molecules are in contact with metal or carbon surfaces, e.g. diamond which act as catalysts for the methane-polymerisation to occur.

Fascinating of course, and undoubtedly these results will be taken in some quarters to mean that we will never run out of oil, Peak Oil being bunkum. But even if there were proven to be vast underground lakes of hydrocarbons, if we cannot recover them fast enough to begin matching the current 30 billion barrels/year of contemporary use and rising, it makes no difference. We should not be thrown any red-herrings that we need not press-on toward a future that is far less dependent on oil, and indeed a better planned use of energy in all its forms.


Russ said...

Interesting post on an effort I didn't know existed. Seems I may have been wrongly barking that oil took millions vs thousands of years to "cook." Still, to build an appetite around something even with these lessor time scales involved, and then consume it in a mere few hundred years, puts a very unrealistic expectation on renewable replacements that operate on weaker real time vs the potent stored solar energy of fossil fuels.

Professor Chris Rhodes said...

Hi Russ,

yes, that thousands/million-year cooking is what is believed in the West to have created the oil we are now recovering, but there is the alternative "abiotic" view.

Hydrocarbons have been detected on other heavenly bodies, where organic life is not known to exist, and so there may well be alternative sources of them.

as I say, however, even if there is a lot of such hydrocarbons at such depths as the calculations indicate there may be, if we can't recover them fast enough, the problem of peak oil remains.