We present an experimental study on the formation and dissociation characteristics of carbon dioxide (CO2) gas hydrates using Raman spectroscopy. The CO2 hydrates were formed from sodium chloride/water solutions with salinities of 0-10 wt %, which were pressurized with liquid CO2 in a stirred vessel at 6 MPa and a subcooling of 9.5 K. The formation of the CO2 hydrate resulted in a hydrate gel w...

This paper deals with the effects of a surfactant additive on the formation of methane hydrate in water system with and without sodium dodecyl sulfate (SDS). The properties of sodium dodecyl sulfate are listed. The results manifested that the presence of SDS could not only accelerate the hydrate formation process, but also increase the partition coefficient of methane between hydrate and vapor ...

We performed a sequence of tests on a partially water-saturated sand sample contained in an x-raytransparent aluminum pressure vessel that is conducive to x-ray computed tomography (CT) observation. These tests were performed to gather data for estimation of thermal properties of the sand/water/gas system and the sand/hydrate/water/gas systems, as well as data to evaluate the kinetic nature of ...

Gas hydrate blockage in pipelines during offshore production becomes a major problem with increasing water depth. In this work, a series of experiments on gas hydrate formation in a flow loop was performed with low flow rates of 0.33, 0.66, and 0.88 m/s; the effects of the initial subcooling, flow rate, pressure, and morphology were investigated for methane hydrate formation in the flow loop. T...

[1] We developed a multicomponent, multiphase, fluid and heat flow model to describe hydrate formation in marine sediments; the oneand two-dimensional model accounts for the dynamic effects of hydrate formation on salinity, temperature, pressure, and hydraulic properties. Free gas supplied from depth forms hydrate, depletes water, and elevates salinity until pore water is too saline for further...

Clathrate hydrates are crystalline compounds composed of hydrogen-bonded water molecules that form polyhedral cavities and trap small guest molecules such as methane, carbon dioxide, cyclopentane (CP), and tetrahydrofuran (THF). Understanding the formation and dissociation of clathrate hydrates is of significant importance to addressing some global challenges such as greenhouse gas mitigation a...

The structure of the carbon dioxide-water interface was analyzed by X-ray diffraction and reflectivity at temperature and pressure conditions which allow the formation of gas hydrate. The water-gaseous CO2 and the water-liquid CO2 interface were examined. The two interfaces show a very different behavior with respect to the formation of gas hydrate. While the liquid-gas interface exhibits the f...

Thermodynamic models are usually employed to predict formation condition of hydrates. However, these thermodynamic require a large amount calculations approach phase equilibrium. Additionally, parameters included in the model need be calibrated based on experimental data, which leads high uncertainties predicted results. With rapid development artificial intelligence (AI), machine learning as o...

An isobaric flow loop added to the Gas Hydrate And Sediment Test Laboratory Instrument (GHASTLI) is being investigated as a means of rapidly forming methane hydrate in watersaturated sand from methane dissolved in water. Water circulates through a relatively warm source chamber, dissolving granular methane hydrate that was pre-made from seed ice, then enters a colder hydrate growth chamber wher...

Clathrate hydrates are of great importance in many aspects. However, hydrate formation and dissociation mechanisms, essential to all hydrate applications, are still not well understood due to the limitations of experimental techniques capable of providing dynamic and structural information on a molecular level. NMR has been shown to be a powerful tool to noninvasively measure molecular level dy...