Tag Archives: shale gas

Clean fossil fuel?

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The amount of energy stored in methane hydrate could be twice that of all other fossil fuel reserves based on data from the US Geological Survey, the New Scientist reported on 31st August, 2013 in an article entitled ‘Buried Treasure’.  At this point, most of you are probably wondering what methane hydrate is and where it is stored.  Microbes on the seabed eating organic matter produce methane molecules that at high pressure and low temperature combine with the water to form a hydrate, which is white crystal.  Large deposits of methane hydrate deposits are believed to lie along continental margins, mostly in ocean sediments.

Natural gas and shale gas (‘Fracking’ on August 28th, 2013) are also methane, which releases less carbon dioxide when it is burned than coal or gas and hence is regarded as cleaner.  However, methane hydrate deposits might have an additional advantage because some research has shown that the methane molecule trapped in the hydrate crystal can be replaced by a carbon dioxide one.  So we might be able to extract methane and simultaneously store carbon dioxide.  Sounds too good to be true and the second law of thermodynamics will ensure that there is a price to be paid somewhere and somehow (see post entitled ‘Sonic Screwdriver’ on April 17th, 2013 for more the 2nd law).

http://www.newscientist.com/article/mg21929320.800-frozen-fuel-the-giant-methane-bonanza.html

https://www.llnl.gov/str/Durham.html

http://www.jogmec.go.jp/english/oil/technology_015.html?recommend=1

Fracking

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The British Prime Minister, David Cameron has argued in an article in the Sunday Telegraph (on August 11th, 2013) that if we don’t back fracking technology then the country will miss an opportunity to help families with their bills and make the country more competitive.  In his article the Prime Minister only makes the economic case in favour of using fracking to extract shale gas.  He completely ignores the environmental costs of these economic gains, which will always be present as in any industrial process – the second law of thermodynamics tells us to expect these costs – a form of increased entropy.  The environmental costs of fracking are still disputed.  Companies and politicians with something to gain from its successful implementation argue that the costs are very low or insignificant.  However, recent research has concluded that more than 100 earthquakes were triggered in a single year in Ohio due to fracking-related activities (J. Geophysical Research: Solid Earth, doi.org/nh5).  The largest of these quakes was of magnitude 3.9 and was caused by pumping pressurised waste water into a deep well.  There are also concerns that waste water from fracking might contaminate groundwater.

A joint report of the Royal Society and the Royal Academy of Engineering has concluded that the fracking process can be successfully managed without significant risks to the environment or society.  However, in France fracking has been banned.  So, the arguments flow in both directions.  As a society we are addicted to energy, and fossil fuels in particular, and hence we need sources of oil and gas.  The risks involved in extracting shale gas by fracking are probably no greater than those associated with oil or natural gas; its just that they tend to occur closer to people’s backyard, which makes people more sensitive to them.  Actually, the technology has been around and used for a long time; see John Kemp’s column at Reuters for an explanation of the process and its history.  However, if we intend to use it on a larger scale then we need to guard against unexpected consequences and be ready to deal with the mess when things go wrong.  When engineers succeed in these two goals then no one will notice but when they fail the public and many politicians will be quick to attribute blame to them, whereas it likely will be our addiction to fossil fuel that is to blame.