Seite - 79 - in Water, Energy, and Environment - A Primer

global consumption of natural gas is currently about 130 Tcf. Withmethanehydratesweare talkingaboutavery largepotential energy resource. It is alsowidelydistributedglobally, andhas the potential to be an indigenous resource for many countries. It is also straightforward to separate the CH4 from its hydrate cage by heating it up or reducing its pressure. Both techniques havebeendemonstratedandarecurrentlybeingexploredactively in public and private research programs in many countries. The production problems arise when one tries to convert this resource intoamarketablecommodityat a reasonablecost. Thepresenceofmostof thehydrateson thedeepsea floorand insediments justbeneath itmeans that extractionmustbecarried outunderextremeconditionsofdepth,pressureand temperature. The methane concentrations are also geographically dispersed, increasing the harvesting costs, undersea infrastructure costs, and transmission costs of bringing the gas to the surface. The fragility of the hydrates also requires that they be handled carefully, avoiding a sudden release of gas and resultant over- pressurization. Environmentally, while CH4 is a powerful greenhouse gas, a saving grace is that CH4’s half-life in the atmosphere is 7.5 years.CO2on the other handhas an atmospheric half-life of hundreds of years. Another problem for CH4 production from hydrates is the fact that shale gas from fracking is just coming into its ownas a major source of competitive natural gas, thus reducing the commercial incentive to develop the hydrates. Unless the cost of producing CH4 from hydrates can be reduced significantly this will remain an important barrier as long as shale gas is available in quantity. The US is one of several countries with an active methane hydrate R&D program. Others include Russia, India, South Korea and Japan. Japan has been a leader in this research for many years, given its lack of indigenous energy resources and its heavy dependence on imports. Japan’s recent problemswith Fossil fuels 79