New hydrate formation methods in a liquid-gas medium

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.

Laboratory Investigation Into the Formation and Dissociation Process of Gas Hydrate by Low‐Field NMR Technique

“…In this work, the low‐field NMR technique is used to monitor the formation and dissociation processes of gas hydrate in sedimentary rocks with different pore size distribution. Methane is used to form gas hydrate, instead of tetrahydrofuran (Gao et al, ; Song et al, ), carbon dioxide (Chen et al, ; Chernov et al, ; Falenty et al, ; Yang et al, ), and Freon (Elistratov et al, ; WitteBolle & Sego, ), which can simulate the real gas hydrate conditions beneath the Earth. Four samples with different pore size distributions are used in our experiments, aiming to consider the effect of pore structure on the formation and dissociation behaviors of the gas hydrate.…”

The dynamics of nucleate boiling of salt solutions at a high heat flux

“…Multiple reduction of heat transfer can be associated with nucleate boiling suppression [13][14][15][16] at liquid film thickening and with a boiling crisis (local liquid separation from the wall by a vapor layer). The problems of fuel combustion and dissociation of gas hydrates are closely related to gas droplet flows [17][18][19][20][21][22][23]. Evaporation of gas-droplet flows are widely used in practice in technical apparatuses [24,25].…”

Nonisothermal desorption at nucleate boiling in a layer of aqueous salt solution

“…The formation of vapor flow and small droplets during combustion of gas hydrates result in a decrease in the combustion temperature and in the efficiency of the technology of gas hydrates combustion [12][13][14][15][16][17]. At liquid gas boiling, a multicomponent mixture is formed (vapor-liquid droplets-crystal hydrates) [18]. Experimental studies of heat and mass transfer during evaporation of a thin layer of aqueous salt solution was discussed in [19][20][21].…”