Solubility in brine

For most gases the solubility in a brine solution is less than the solubility in pure water. This is called the salting-out effect. The following equation, proposed by Sechenov more than a century ago, can be used to approximate the salting-out effect  

Electrolyte solubility in the electrolyte solution I - concentration of the electrolyte k - salting-out coefficient. 

Various units could be used for the solubilities, but the values given in the next section, the solubilities of both the acid gas components and the NaCl must be in molality (moles of salt per kilogram of solute). 

Rearranging Equation (4.7) to a form that is applicable for calculating the solubility in the electrolyte solution given the solubility on pure water. 

The salting-out coefficient is a function of the temperature, but it is approximately independent of the pressure and assumed to be independent of the nature of the phase of the solute. 

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Fig. 8.23 Solubility of methane (a) in NaCl at 1 atm and 283.15°K and (b) in CaCl2 solutions at 37.4 atm and 298.15°K. Reprinted from Sorensen H, Pedersen KS, Christensen PL (2002) Modeling gas solubility in brine. Organic Geochem 33 635-642. Copyright 2002 with permission of Elsevier.

Removing benzene and other aromatic compounds from a plant s effluent water is an increasingly common environmental requirement. This is typically achieved with a steam stripper. There is a rather neat trick, which can increase the stripper s efficiency adding saltwater to the stripper feed. Aromatics, especially benzene, are far less soluble in brine than they are in freshwater. But, of course, the brine will be more corrosive than salt-free freshwater. 

In this chapter, the solubility of acid gas in water and brine is also discussed. Although brine is not a problem in the injection system, the reservoir may contain brine and thus the solubility in brine is important in reservoir modeling. 

Temperature limitations are also important. In order for the surfactant to be effective it should be soluble at the temperature of the reservoir. Materials, such as some of the petroleum sulfonates, have very low solubilities in brines at temperatures below about 150 F (71 C). Consequently, they produce almost no foam below this temperature. Other surfactants, e.g., ethoxylated alcohols, become less soluble as the temperature is increased. These materials become limited in their effectiveness in higher temperature applications. An increase in temperature may also decrease the surface-active property of some surfactants. 

Thus, the ability of the model to predict the chemistry of heavy metals in brine in a sense was used to test the validity of the carbonate subroutine. The general procedure was to assume that the trace metal solubility in brine was controlled by either the carbonate, basic carbonate or hydrous oxide form of the metal. The heavy metal and carbonate ion activities were determined by the model. The resultant calculated solubility of the heavy metals in brine was then compared with experimentally determined values. 

Figure 84 may be used to estimate a value of p below the saturation pressure. If the accuracy of other data on the reservoir justifies an additional refinement, the value of for brines of various total salt concentration can be estimated provided a correction is made for the decreased gas solubility in brine as is shown in the example below. 

This section has demonstrated that some commercially available surfactants are soluble in brines of extreme salinity and hardness and also form effective mobility control foams under these conditions. The remainder of this chapter is devoted to the development of a better understanding of the adsorption properties of foam-forming surfactants, mainly those for high-salinity conditions. It is hoped that this discussion will contribute to the development of a systematic approach for selecting or formulating surfactants with minimal adsorption levels. 

Price LC, Blount CW, MacGowanD, Wenger L (1981) Methane solubility in brines with application to the geopressured resomce. In Proc 5th Conf Geopressured Geothermal Energy, Baton Rouge, Louisiana, p 205-214... 

The importance of minimizing adsorption has provided the impetus for a number of adsorption studies of both anionic and nonionic surfactants on representative reservoir solids most of these deal with surfactant adsorption from aqueous solution. In general it has been found that the adsorption of petroleum sulfonates on mineral adsorbents increases with decreasing solubility in the solvent. Gale and Sandvik (1) have found that petroleum sulfonate adsorption from brine on clay minerals increased with molecular weight and therefore decreasing solubility in brine. 

This model accounts for the observation that the fraction of adsorbed sulfonate increases with microemulsion brine content within each of the TRS 10-410/glycol ether, PDM-334/glycol ether, and PDM-334/butoxytriglycol microemulsion series. Sulfonate adsorption increases with increasing brine content of the microemulsion for two reasons the sulfonate-adsorbent interactions are enhanced due to the greater positive charge on the surface of the adsorbent the adsorbed sulfonate tends not to re-solubilize because of its inherently low solubility in brine. 

A literature survey of surfactant adsorption data indicates that the most common isotherms are the ones in which the selectivity is declining with increasing surfactant concentration and that adsorption isotherms cover a very limited concentration range because the surfactants have low solubility in brines. Some of the results indicate the presence of a maximum in the isotherm, while some show only a monotonic increase in adsorption with increasing concentration. Extensive efforts have been made to explain the presence of the maxima in some of the isotherms. 

Felmy et al, (18) investigated foe solubility of Pu(OH)3 under reducing conditions in deioni water and brine solution. They deriv a much lower solubility product (log K = -26.2) (see Table I) than foe value (log K = -19.6) reported in foe literature (iP). However, foe solubility in brines [I 6 2Uid I - 10] was found to be larger than foat in deionized (I = 0) waters. The solubility of Pu(OH)3 in brines was accurately predicted with foe Pitzer ion-interaction model using only foe parameters for binary interactions between Pu and Cl". 

Ammonia is dissolved in brine and the solution is added to the top of a tower up which carbon dioxide is passed. Ammonium hydrogencarbonate is formed. This reacts to form a precipitate of sodiumhydrogen carbonate, which is sparingly soluble in brine... 

The use of a corrosion inhibitor at elevated temperatures sometimes requires more tests than the evaluation of inhibitor efficiency alone. Solubility may be affected in an unexpected way as the temperature increases. For example, some organic inhibitors have a lower solubility in brine at elevated temperatures than at amhient temperatures. 

Ethyl acetoacetate is a colourless liquid, d, i 03, slightly soluble in water, but almost insoluble in brine. It has a faint but pleasant odour. It is widely used in chemical syntheses. 

The second most common alkalinity control agent is lime [1305-78-8] normally in the form of calcium hydroxide [1303-62-0], used in both water and oH muds. In the latter, the lime reacts with added emulsifiers and fatty acids to stabHi2e water-in-oH emulsions. Lime is used in brine systems containing substantial quantities of soluble calcium and in high pH lime muds. Concentrations are ca 6—57 kg/m (2—20 lb /bbl) (see Lime AND LIMESTONE). 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

A traditional system for the preparation of table olives, involves a treatment of the fresh fruit with a solution of NaOH to hydrolised the bitter glycoside oleuropein, followed by a lactic fermentation in brine. The modifications that take place on pectic polysaccharides of olives (Manzanilla variety) during this process was smdied. Processing induced a net loss of polysaccharides soluble in sodium carbonate and a paralel accumulation of water and Imidazole/HCl soluble polysaccharides. A general decrease of the apparent molecular weight of water and carbonate soluble polysaccharides was also detected. 

Brines have inherent corrosive properties and therefore are not suitable. Ethylene glycol is preferred because of its low cost and low solubility in hydrocarbons. 

Sediment may be added by bulk mixing via imbricate thnisting (Bebout and Barton 2002), dehydration (Class et al. 2000), or melting (Johnson and Plank 1999). The latter two may differ in their P-T conditions and, therefore, residual mineralogy as well as relevant partition coefficients. In general, fluids are less effective transport agents than melts (i.e., trace elements are more soluble in melt than in pure water or even brine), but fluid/solid partitioning can fractionate some elements, notably Ba-Th and U-Th, more than melt/solid. However, as pressure increases, the distinction between fluid and melt decreases as their mutual solubility increases and they approach a critical end-point. 

Zirrahi Z., Azin R., et al. Mutual solubility of CH4, C02, H2S, and their mixtures in brine under subsurface disposal conditions. 2012 Fluid Phase Equilibria 299 171—... 

Weare, J.H., 1987, Models of mineral solubility in concentrated brines with application to field observations. In I. S.E. Carmichael and H.P Eugster (eds.), Thermodynamic Modeling of Geological Materials Minerals, Fluids and Melts. Reviews in Mineralogy 17,143-176. 

Soy Protein Concentrates. Both non-functional (low or no solubility) and functional (good solubility, emulsification capacity, and dispersibility) soy protein concentrates (70% protein, dry basis) are commercially available for use in meat products (2-4, 6, j), 15) Normally, a highly functional product with no harsh or bitter flavors is desirable. When used to replace lean meat, non-hydrated concentrate can be used at levels up to 6-7% in finished nonspecific emulsion meats Higher replacement levels or formulas with specific cost/nutrition requirements may use soy protein concentrate with a judicious amount of textured soy protein (6). Excellent yields, cost savings, texture, flavor and nutrient profiles are possible. However, most soy protein concentrates lack sufficient solubility or sufficiently low viscosities to be used in brines for absorption or injection into whole muscle tissue. When legal standards for protein content exist (13), more concentrate must be used to achieve legal minimums. Brine viscosities increase and uniform distribution of brine components throughout the specific whole muscle piece is restricted. Finished product appearance and flavor are easily compromised. Thus, use of soy protein concentrates in whole muscle applications is limited. 

Because HDO or H2 0 molecules cannot be expected to have the same solubility in the brine of the main solvent species H2 0 (hereafter simply denoted H2O), their differential behavior must be accounted for by introduction of the appropriate activity coefficient ratio (or isotope salt effect cf Horita et ah, 1993a,b) F ... 

Freeze concentration processes are based on the difference in component concentrations between solid and liquid phases that are in equihbrium. Most minerals and many organics grow less soluble in water as the temperature decreases. When an aqueous solution is cooled, ice usually crystallizes as a pure material, and dissolved components in the aqueous waste stream are concentrated in the remaining brine, thereby reducing the volume of waste. 

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