Despite all this clamor among the environmentalists about the real and imaginary flip-sides of using fossil fuels and the need to shift to alternate sources of energy, the world remains heavily reliant on the three main types of fossil fuels, i.e. coal, oil and natural gas. Natural Gas is the cleanest and most efficient form of hydrocarbon. It can be easily used to substitute the other two forms and lower the possible damages to the environment. But the question remains: Is there enough of natural gas to fulfill our need?
Yes, there is. Natural Gas Hydrates are the largest and most widely spaced accumulations of hydrocarbons in the world. Methane Gas Hydrates comprise of a single CH4 molecule enclosed in a cage of H2O molecules having an ice-like appearance. The two basic conditions required for hydrate formation are low temperature and high pressure. Since these types of conditions are mainly found in the Arctic Permafrost region and the deep ocean bottoms, most of the naturally occurring hydrate reservoirs are found there.
Two factors make gas hydrates attractive as a potential energy resource:
(1) The huge volumes of methane that is apparently trapped as clathrate within the upper 2000 m of the Earth's surface, and
(2) The wide geographical distribution of gas hydrates.
However, we have been unable to extract their potential due to a combination of technical and logistical hassles. The proposed technology presents an innovative, promising and sustainable source of energy for the future via the injection of CO2 in hydrate reservoirs to produce CH4 and then microbial action on CO2 in reservoir to convert it to CH4 via methanogenesis and reformation of a methane gas hydrate, forming a complete cycle and providing an ever-lasting source of energy. Also, the project utilises a form of carbon capture and sequestration.
The proposal involves the injection of CO2 gas into the hydrate reservoir. CO2 is more thermodynamically stable than CH4, the hydrate cages prefer occupation by the CO2 rather than CH4 and due to this, CH4 is liberated from the hydrate reservoirs and a CO2 hydrate is formed in instead. In forming mixed CH4 and CO2 hydrates, the CH4 molecules occupy both the large and small cages of type sI hydrates, whereas the CO2 molecules only occupy the large cages. Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Organisms capable of producing methane have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria.
Hence, we take down two birds with one stone: combat global warming by lowering CO2 in the atmosphere and providing more energy to fuel the future's growth.