Gas Hydrates Produced Under ‘SPACE’ Conditions
08, Jan 2019
Prelims level : Climate Change Mains level : GS 3: Conservation, Environmental Pollution and Degradation, Environmental impact Assessment
- Researchers at Indian Institute of Technology (IIT) Madras have experimentally shown that methane and carbon dioxide (CO2) can exist as gas hydrates at temperatures and pressures seen in interstellar atmosphere.
- In terrestrial conditions, gas hydrates are formed naturally under the sea bed and glaciers under high pressure, low temperature conditions.
- The researchers have stimulated the conditions of deep space (very low pressure and temperature) to produce methane and CO2 hydrates in the lab
- It is been inferred from the produced carbon dioxide hydrate that there could be high possibility of sequestering or storing carbon dioxide as hydrates by taking advantage of ice exiting in environmental conditions favourable for hydrate formation.
- It is said that in these environmental conditions, the carbon dioxide will have enough energy to interact with ice, and hence both molecules will have enough mobility to allow interaction to form carbon dioxide hydrate.
- It is further said that CO2 hydrate is thermodynamically more stable than methane hydrate. So if methane hydrate has remained stable for millions of years under the sea bed, it would be possible to sequester gaseous CO2 as solid hydrate under the sea bed
About Gas Hydrates:
- Gas hydrate is a solid ice-like form of water that contains gas molecules in its molecular cavities. In nature, this gas is mostly methane. Methane gas hydrate is stable at the seafloor at water depths beneath about 500 m. The gas hydrate stability zone extends into the seafloor sediments down to a depth where temperature exceeds gas hydrate stability, usually some 10s to 100s of meters beneath the seafloor.
- Large quantities of gas hydrates exist on the world’s continental margins. Methane from gas hydrates may constitute a future source of natural gas.
- Gas hydrates are also important for seafloor stability studies, because “melting” gas hydrate may cause seafloor “land” slides. Methane is a potent greenhouse gas. Methane released from gas hydrate may therefore play a significant role in climate change.
- It is important to distinguish between the climate change aspects of methane released naturally from gas hydrates and those of methane produced from gas hydrates for energy use. By burning methane or using it in fuel cells, the methane is converted to CO2. – just like burning coal or oil.
- Combustion of methane, however is more CO2 efficient than that of any other hydrocarbon, e.g., twice as efficient as burning coal. Hence, using methane from gas hydrate as an energy resource would be, compared to other hydrocarbons, relatively climate friendly.