New hydrate formation methods in a liquid-gas medium

A A Chernov,M V Bartashevich,A V Meleshkin,M G Vlasenko,D S Elistratov,A A Pil’Nik,I V Mezentsev

doi:10.1038/srep40809

Abstract

Conceptually new methods of hydrate formation are proposed. The first one is based on the shock wave impact on a water-bubble medium. It is shown that the hydrate formation rate in this process is typically very high. A gas hydrate of carbon dioxide was produced. The process was experimentally studied using various initial conditions, as well as different external action magnitudes. The obtained experimental data are in good agreement with the proposed model. Other methods are based on the process of boiling liquefied gas in an enclosed volume of water (explosive boiling of a hydrating agent and the organization of cyclic boiling-condensation process). The key features of the methods are the high hydrate formation rate combined with a comparatively low power consumption leading to a great expected efficiency of the technologies based on them. The set of experiments was carried out. Gas hydrates of refrigerant R134a, carbon dioxide and propane were produced. The investigation of decomposition of a generated gas hydrate sample was made. The criteria of intensification of the hydrate formation process are formulated.

Highlights

New methods of hydrate formation are proposed
The majority of studies were aimed at finding the methods of prevention of hydrate formation and avoiding solid phase accumulation in systems of underground and overground equipment at oil and gas deposits[4,5,6]
In this work we propose new hydrate formation methods based on the mechanical or/and thermal influence on a bubble medium

Summary

Some information about gas hydrates

Gas hydrate is a solid crystalline compound that forms, under certain temperature and pressure conditions, from water (liquid water, ice or water vapor) and a low-molecular gas[5,6]. This means that, for the shock waves of higher magnitude, the rate of hydrate formation is higher. The additional effect is provided by the fact that, behind the shock wave of a higher magnitude, the medium falls in the area of a higher decompression related to the hydrate formation curve (which increases the hydrate mass growth rate) The enhancement of this effect can be achieved by making the initial pressure close to the equilibrium pressure for a given temperature (in the described experiments it is 1.3 MPa). The refrigerant remained from the hydrate formation in the first cycle of the process condenses on the walls of the working section, streams down to the bottom of the chamber and mixes with the already boiling layer

Conclusion

Author Contributions

Findings

Additional Information