The formation of hydrate plugs in oil and gas pipelines is a serious industrial problem and recently there has been an increased interest in the use of alternative hydrate inhibitors as substitutes for thermodynamic inhibitors like methanol. We show here that antifreeze proteins (AFPs) possess the ability to modify structure II (sII) tetrahydrofuran (THF) hydrate crystal morphologies by adherin...

We have attempted to make the gas hydrate crystal in vegetable in order to extend the shelf life of fresh vegetable as preservation technique instead of freezing. As a result, it was confirmed that gas hydrate can be formed in onion tissue at 5 o C by pressurizing between 0.4 and 0.8 MPa Xe pressure. However, the detail conditions regarding to gas hydrate formation in vegetable tissue and their...

[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...

One of the main problems in oil recovery via the gas injection is the formation of hydrates in thelines. In order to prevent the formation of hydrate in these lines, which leads to the blockage andsometimes explosion, at first, the equilibrium formation conditions must be determined and then toprevent its formation by changing the thermodynamic conditions or by adding the inhibitors. In thisres...

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...

The effect of overpressure on gas hydrate and free gas distribution in marine sediments is studied using a one-dimensional numerical model that couples sedimentation, fluid flow, and gas hydrate formation. Natural gas hydrate systems are often characterized by high sedimentation rates and/or low permeability sediments, which can lead to pore pressure higher than hydrostatic (overpressure). To q...

An hybrid absorption-hydration method was adopted to recover C2H4 from C2H4/CH4 binary gas mixtures and the hydrate formation conditions of C2H4/CH4 mixtures was studied experimentally in diesel in water (w/o) emulsions. Span 20 at a concentration of 1.0 wt% in the aqueous phase was added to form water in diesel emulsions before hydrate formation and then hydrate in diesel slurry was separated ...

This paper describes a one-dimensional numerical model for natural gas production from the dissociation of methane hydrate in hydrate-capped gas reservoir under depressurization and thermal stimulation. Some of the hydrate reservoirs discovered are overlying a free-gas layer, known as hydrate-capped gas reservoirs. These reservoirs are thought to be easiest and probably the first type of hydrat...

Small-scale morphology of gas hydrate is important for understanding the formation of gas hydrate deposits, for estimating the concentrations of gas hydrate from geophysical data, and for predicting their response to climate change or commercial production. The recent use of borehole pressure coring tools has allowed marine gas-hydrate-bearing sediments to be recovered with centimeter to sub-mi...

The effect of the concentration of kinetic hydrate inhibitors, polyvinylpyrrolidone (PVP), and polyvinylcaprolactam (PVCap) on the onset and growth of synthetic natural gas hydrates is investigated by measuring the hydrate onset time and gas consumption rate. Although the hydrate onset time is extended by increasing the concentration from 0.5 to 3.0 wt % for both PVP and PVCap, the growth rate ...