Structural changes and preferential cage occupancies were examined for ethane hydrate and ethane-methane mixed gas hydrates with five compositions in a pressure range of 0.2 to 2.8 GPa at room temperature. X-ray diffractometry and Raman spectroscopy showed the following structural changes. The initial structure, structure I (sI), of ethane hydrate was retained up to 2.1 GPa without any structur...

â  abstract: in this work, the kinetics of ethane hydrate formation has been studied experimentally and a kinetic model based on chemical affinity has been described for predicting the hydrate growth process in the stirred batch reactor at a constant volume. the experiments were done with both pure water and aqueous solution of sodium dodecyl sulfate (sds). the effect of sds on formation kineti...

The kinetics of film growth of hydrates of methane, ethane, and methane-ethane mixtures were studied by exposing a single gas bubble to water. The morphologies, lateral growth rates, and thicknesses of the hydrate films were measured for various gas compositions and degrees of subcooling. A variety of hydrate film textures was revealed. The kinetics of two-dimensional film growth was inferred f...

  Abstract: In this work, the kinetics of ethane hydrate formation has been studied experimentally and a kinetic model based on chemical affinity has been described for predicting the hydrate growth process in the stirred batch reactor at a constant volume. The experiments were done with both pure water and aqueous solution of sodium dodecyl sulfate (SDS). The effect of SDS on formation kineti...

based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. expressions for the supersaturation are obtained in isothermal and isobaric regimes. the results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to othe...

abstract: â in this study, the change in the crystalline structure of gas hydrate was predicted for ternary mixture of methane-ethane-water. for this purpose, the tangent plane distance (tpd) minimization method was used. first, the calculations were performed for the binary mixtures of methane-water and ethane-water as the gas and liquid phases. the results show that for a binary mixture of th...

A Raman spectrometer extensively modified for deep ocean use was used to measure synthetic hydrates formed in an ocean environment. This was the first time hydrates formed in the ocean have been measured in situ using Raman spectroscopy. Gas hydrates were formed in situ in the Monterey Bay by pressurizing a Pyrex cell with various gas mixtures. Raman spectra were obtained for sI methane hydrate...

Based on driving force for crystallization of one-component gas hydrate, in this report an expression for the supersaturation for crystallization of multicomponent gas hydrate is derived. Expressions for the supersaturation are obtained in isothermal and isobaric regimes. The results obtained are applied to the crystallization of hydrates of mixtures of methane plus ethane and can apply to ...

The hydrate structure type and dissociation behavior for pure methane and methane-ethane hydrates at temperatures below the ice point and atmospheric pressure were investigated using in situ Raman spectroscopic analysis. The self-preservation effect of sI methane hydrate is significant at lower temperatures (268.15 to 270.15 K), as determined by the stable C-H region Raman peaks and AL/AS value...

hydrates are crystalline compounds similar to ice, with guest molecules like methane and ethane trapped inside cavities or cages formed by the hydrogen bounded framework of water molecules. these solid compounds give rise to problems in the natural gas oil industry because they can plug pipelines and process equipments. low dosage hydrate inhibitors are a recently developed hydrate control tech...