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Volume of association

To prepare gas for evacuation it is necessary to separate the gas and liquid phases and extract or inhibit any components in the gas which are likely to cause pipeline corrosion or blockage. Components which can cause difficulties are water vapour (corrosion, hydrates), heavy hydrocarbons (2-phase flow or wax deposition in pipelines), and contaminants such as carbon dioxide (corrosion) and hydrogen sulphide (corrosion, toxicity). In the case of associated gas, if there is no gas market, gas may have to be flared or re-injected. If significant volumes of associated gas are available it may be worthwhile to extract natural gas liquids (NGLs) before flaring or reinjection. Gas may also have to be treated for gas lifting or for use as a fuel. [Pg.249]

The Azeri-Chirag-Guneshli reservoirs contain crude oil with a large volume of associated natural gas. The development of these reserves, have significant implications for the management of Azerbaijan s natural gas resources. [Pg.50]

The molecular interpretation of thermodynamic data of temperature and pressure effects on proteins and their reactions is based on the data obtained from small molar mass model compounds in water. Weber and Drickamer [75] have pointed out the role of mechanical effects on the volume of association of molecular complexes by introducing molecular spacers that prevent molecules to get in close contact. As can be seen from Table 2, these mechanical effects can show up considerably in the volume changes, ft is clear that such effects should also influence hydrophobic interactions in proteins. [Pg.11]

Osmotic stress measures forces corresponding to pressures over six decades, from 0.01 to 10,000 atm. With X-ray diffraction by ordered arrays, as shown in Figure 1, molecular dimensions and intermolecular spacings can be obtained with accuracies often better than 0.2 A reproducibility. Alternatively, with probes of ionic channel conductance or of protein activity, the behavior of single molecules can be observed and the osmotically sensitive part of the underlying structural transformation can be extracted. Consequently, the change in the volume of associated water as the system goes between active and inactive forms can also be extracted. [Pg.183]

Pancharoen, M., Thiele, M.R., and Kovscek, A.R. 2010. Inaccessible Pore Volume of Associative Polymer Floods. Paper SPE 129910 presented at the SPE Improved Pil Recovery Symposium, Tulsa, 24-28 April. DPI 10.2118/129910-MS. [Pg.374]

To sum up, in all cases ionic liquids are modelled using five molecular parameters m, the chain length, a, the diameter of the spheres forming the chain, e, the energy of interaction between them, Khb, the volume of association and ehb, the association energy. The chain... [Pg.309]

In Section 5.2.8 we shall look at pressure-depth relationships, and will see that the relationship is a linear function of the density of the fluid. Since water is the one fluid which is always associated with a petroleum reservoir, an understanding of what controls formation water density is required. Additionally, reservoir engineers need to know the fluid properties of the formation water to predict its expansion and movement, which can contribute significantly to the drive mechanism in a reservoir, especially if the volume of water surrounding the hydrocarbon accumulation is large. [Pg.115]

There is always some degree of adsorption of a gas or vapor at the solid-gas interface for vapors at pressures approaching the saturation pressure, the amount of adsorption can be quite large and may approach or exceed the point of monolayer formation. This type of adsorption, that of vapors near their saturation pressure, is called physical adsorption-, the forces responsible for it are similar in nature to those acting in condensation processes in general and may be somewhat loosely termed van der Waals forces, discussed in Chapter VII. The very large volume of literature associated with this subject is covered in some detail in Chapter XVII. [Pg.350]

Now suppose e(a) denotes the total void volume associated with pores of radii < a, per unit volume of the porous medium. This includes the contributions of any dead-end pores. Chough these are not taken into account in the distribution function f(a,ri). Then we shall write... [Pg.73]

In Equation (5.58) the outer summation is over the p points q which are used to sample the Brillouin zone, is the fractional weight associated with each point (related to the volume of Brillouin zone space surrounding q) and vi are the phonon frequencies. In addition to the internal energy due to the vibrational modes it is also possible to calculate the vibrational entropy, and hence the free energy. The Helmholtz free energy at a temperature... [Pg.313]

An extra amount of free volume is associated with chain ends, which are capable of wagging in a way that is not possible in the middle of a chain. Accordingly, as molecular weight decreases, Vj- increases, which, in turn, decreases Tg. The following expression has been found to describe this molecular weight dependence ... [Pg.255]

It is convenient to begin by backtracking to a discussion of AS for an athermal mixture. We shall consider a dilute solution containing N2 solute molecules, each of which has an excluded volume u. The excluded volume of a particle is that volume for which the center of mass of a second particle is excluded from entering. Although we assume no specific geometry for the molecules at this time, Fig. 8.10 shows how the excluded volume is defined for two spheres of radius a. The two spheres are in surface contact when their centers are separated by a distance 2a. The excluded volume for the pair has the volume (4/3)7r(2a), or eight times the volume of one sphere. This volume is indicated by the broken line in Fig. 8.10. Since this volume is associated with the interaction of two spheres, the excluded volume per sphere is... [Pg.554]

Only a fraction of the chain segments will be present in this spherical shell, but whatever their number is, it will increase with the degree of polymerization n. Therefore, in the volume element associated with the expansion of the coil, the volume fraction of chain segments 0 is proportional to n/dV, or 0 n/a ro dro ... [Pg.618]

Large volumes of LPG are stored to meet peak demand during cold seasons. LPGs are both volatile and flammable and must be stored and handled in special equipment. Standards for storing and handling LPG are pubHshed by the National Fire Protection Association (5) and API (6). [Pg.186]

Magnesium is employed ki a wide variety of appHcations, based on its chemical, electrochemical, physical, and mechanical properties. The International Magnesium Association (IMA) divides the markets for magnesium kito 10 categories and tracks the volume of primary magnesium shipments to each market area on an annual basis. [Pg.323]

The use of fixed bed catalysts is described in several patents (33—37). Methods of operation include upflow, trickle bed, and even vapor phase. Typically, a large volume of solvent is used to moderate the temperature rise associated with the high heat of reaction for nitro group reduction. [Pg.238]

Discernible associative character is operative for divalent 3t5 ions through manganese and the trivalent ions through iron, as is evident from the volumes of activation in Table 4. However, deprotonation of a water molecule enhances the reaction rates by utilising a conjugate base 7T- donation dissociative pathway. As can be seen from Table 4, there is a change in sign of the volume of activation AH. Four-coordinate square-planar molecules also show associative behavior in their reactions. [Pg.170]


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