1 Alma Mater Studiorum Università di Bologna, Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Via Terracini 28, Bologna, Italy [email protected] 2 Politecnico di Milano, DCMIC, Milano (Italy) 3 Università di Roma “La Sapienza”, Dipartimento di Ingegneria Chimica, Roma, Italy 4 CNRIstituto di Ricerche sulla Combustione, Napoli (Italy) 5 D’Appolonia SpA, San Do...

Clathrate hydrates are crystalline compounds formed by a physically stable interaction between water and relatively small guest molecules. Under suitable conditions of guest pressure and temperature, water molecules, via hydrogen bonds, form into polyhedral cavities that connect to give space-filling frameworks. Because of partial cage filling, these crystalline compounds are nonstoichiometric....

The phase diagram for methane + water is explained, in relation to hydrate applications, such as in flow assurance and in nature. For natural applications, the phase diagram determines the regions for hydrate formation for twoand three-phase conditions. Impacts are presented for sample preparation and recovery. We discuss an international study for “Round Robin” hydrate sample preparation proto...

The stability of hydrate frameworks is influenced by guest molecules capable of hydrogen bonding with surrounding water molecules. Four remarkable features from the ammonium fluoride incorporation into a crystalline hydrate matrix provide important information on the thermodynamic stability, formation kinetics, structural characteristics, and molecular behavior in clathrate hydrate systems.

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...

The kinetics of the initial stage of crystallization of one-component gas hydrates in aqueous solutions are analyzed. The temporal evolution of the volume of hydrate crystallized and the moles of gas consumed are determined. Expressions are derived for the supersaturation dependence of the hydrate crystallite growth rate and the induction time in hydrate crystallization. These expressions are u...

The importance of kinetic hydrate inhibitors is increasing due to its low cost compared to thermodynamic inhibitors and the corresponding benefits for exploitation of small marginal fields. This stimulates further investigations of the primary mechanisms for the induction times before onset of massive hydrate growth. The hypothesis in this work is that combinations of transport rate limitations...

Uniform manganese hexacyanoferrate hydrate nanocubes are prepared via a simple chemical precipitation method at room temperature. Due to both micro/mesopores of the Prussian blue analogue and nanocubic structures, the manganese hexacyanoferrate hydrate nanocubes allow the efficient charge transfer and mass transport for electrolyte solution and chemical species. Thus, the manganese hexacyanofer...

Additives per kg: Vitamins – E672 vitamin A 5,000 IU; vitamin C 50 mg; E671 vitamin D3 250 IU; 3a700 vitamin E 25 mg. Trace elements E5 Manganese (manganese chelate of glycine hydrate) 7,000 mg; E6 Zinc (zinc chelate of glycine hydrate) 6,500 mg; E1 Iron (iron chelate glycine hydrate) 6,000mg; E4 Copper (copper chelate of glycine hydrate) 4,000 mg; E2 Iodine (potassium iodide) 5 mg; E8 Selenium...

Gas hydrates presented as form of segregated bodies have been observed on shallow subsurface sediments. However, most gas hydrate physics models describe that hydrates occur in pore space in deep subsurface sediment. A new model considers gas hydrate as segregated bodies to derive elastic properties of hydrates bearing sediments and gas hydrate saturation. The predicted elastic properties based...