Production of Synthetic Natural Gas Hydrates from Ice in Closed Reactors at Thermocycling

Semenov M.E., Portnyagin A.S., Shitz E.Yu.

The ability to concentrate the gas into a solid clathrate structure and the self-preservation property of gas hydrates at subzero temperature are the basis for the scientific and technical directions associated with the creation of technologies for natural gas storage and transportation, as well as utilization of associated petroleum gas. At present, only the block schemes are given in the domestic literature, with the example of which it was shown that the hydrate method of natural gas storage and transportation on the territory of Russia is quite promising and can be an addition to existing technologies. Therefore, the search for a simpler, energy-saving method of gas hydrates synthesis in order to create an alternative technology for natural gas storage and transportation in the form of a hydrate is essential. The article presents the experimental results of natural gas hydrates accumulation in simple closed-type reactors from the «ice-gas» system based on the use of native low temperatures during thermocycling and the absence of any external dynamic influences on the reaction system. The temperature regime for the synthesis of natural gas hydrates in closed reactors is selected. It is shown that three different forms of hydrate are formed during the synthesis of natural gas hydrates from ice in the absence of external dynamic influences in closed reactors: a fine powder at the bottom of the reactor, the initial ice hemisphere forms and filaments. Hydrates of natural gas with a high specific gas content from ice hemispheres are obtained on the basis of distilled water at a selected temperature regime. It has been established that accumulation of predominantly heavy components of natural gas occurs in hydrates synthesized from ice in closed reactors, and the free volume of the reactor is enriched with methane.

Key words: natural gas hydrate, closed reactor, ice, size of ice fractions, thermocycling, specific gas content.

Science and Education, 2017, No.3, pp.76-81