Hydrocarbon water systems, other

Other Hydrocarbon - Water Systems. Interaction parameters were generated for the benzene - water system. The data used were those of Scheffer (31 ) > Rebert and Kay 35) > and Connolly... 

Figure 7. Critical p T) curves of some hydrocarbon + water systems (1 = benzene + water 2 = benzene + heavy water 3 = methylbenzene + water 4 = 1,2-dimethylbenzene + water 5 = 1,3,5-trimethylbenzene + water 6 = cyclohexane + water 7 = ethane + water 8 = butane + water 9 = naphthalene + water (11) 10 = biphenyl + water (11) 11 = fluorobenzene + water systems 9 and 10 belong to class II, their critical endpoints llg indicated by , all others to class III according to [6], where also references are given).

Once a fire has started, control of the fire can be accomplished in several ways through water systems (by reducing the temperature), carbon dioxide or foam systems (by limiting oxygen), or through removal of the substrate (by shutting off valves or other controls). Chapter 4 provides detailed discussion on the theories of fire and specific information on hydrocarbons, as well as chemical specific fire characteristics. 

For gas absorption, the water or other solvent must be treated to remove the captured pollutant from the solution. The effluent from the column may be recycled into the system and used again. This is usually the case if the solvent is costly (e.g., hydrocarbon oils, caustic solutions, amphiphilic block copolymer). Initially, the recycle stream may go to a treatment system to remove the pollutants or the reaction product. Make-up solvent may then be added before the liquid stream reenters the column. 

The purpose of the facilities described in this chapter is to provide for safe handling of various drainage materials and emergency streams, so that they may be safely routed to the sewer, tankage, flare, or other appropriate destination. Drainage systems specified herein ensure that flammable or toxic materials may be disposed of without hazard of fire or injury when equipment is taken out of service. Also described are systems to handle process water drawoffs, cooling water, and other aqueous effluent streams which may be contaminated with hydrocarbons, and which could otherwise create hazardous conditions if they were discharged directly to the sewer. 

Pieratti et ol. (1955) have developed correlations for the prediction of the activity coefficients at infinite dilution for systems containing water, hydrocarbons and some other organic compounds. Their method, and the data needed for predictions, is described by Treybal (1963) and Reid et al. (1987). 

We believe that the SRK equation of state has been pushed to its limits. Some improvements in its ability to describe the behavior of hydrocarbon water-other components systems can probably be made. Some of our earlier work indicated that the vapor liquid behavior of selected organic water systems could be reasonably well described (7, 23). Unfortunately, the results of this work could not be extended beyond the range of data used in the fitting process. 

Of the many possible non-hydrocarbon - water binary systems which are related to substitute gas processes, the data on only the water binaries containing H2S, C02, N2, and NH3 were used in this study. The treatment of hydrogen, a quantum gas, is different from that of the other gases. A separate paper will deal with the correlation of the data on hydrogen mixtures. 

Alcohols exhibit a bifunctional nature in aqueous solution. On the one hand, there exists a hydrophobic hydrocarbon group which resists aqueous solvation on the other, there is the hydrophilic hydroxyl group which interacts intimately with the water molecules. Franks and Ives (30, 31) have reviewed experimentation and theoretical treatises on the structure of water, the structure of liquid alcohols, and the thermodynamic, spectroscopic, dielectric, and solvent properties and P-V-T relationships of alcohol-water mixtures. Sada et al. (27) reviewed, in particular, the salt effects of electrolytes in alcohol-water systems and discussed the various correlations of the salt effect applied to these systems. Inorganic salts were used almost universally in these salt effect studies. 

Laser-Raman spectroscopy is a new method with considerable potential for providing an explanation of how the surroundings inside the aggregates influence the crystalline state of the hydrocarbon chains and other groups (25, 26). It seems probable, however, that an important area of research on the phase equilibria proper would concentrate on attempts to throw light on the exact thremodynamic criteria for the association processes. Ekwalls studies of the water activities of mesophases in the system water-decanol-sodium caprylate are an example of such research (4). However, thermodynamic treatment of the association processes presupposes measurements of the activities of several... 

Installation and operational qualification work includes verification of temperature, pressure, and flow rates, instrument calibration, and thorough flushing of the entire system to remove oil, metal particles, and other contaminants. The type of testing and acceptance limits listed in the validation protocol may vary from firm to firm however, compressed air with product contact should be tested for such quality attributes as hydrocarbons, water vapor, and microbial content (typically less than 0.1 CFU/cu. ft.)... 

The KG/F values in aqueous systems for the solvents listed in Table 13-5 can be used as approximate values for other solvents with similar structures. The aromatic hydrocarbon, toluene, is in this respect an exception where its partition coefficient in the air/water system has a value of KG/F = 0.5. 

Finally, in the discussion of reverse microemulsion systems, mention should be made of one of the most widely studied systems. The surfactant, sodium bis(2-ethylhexyl) sulfosuccinate or Aerosol-OT (AOT), is one of the most thoroughly studied reverse micelleforming surfactants since it readily forms reverse micelle and microemulsion phases in a multitude of different solvents without the addition of cosurfactants or other solvent modifiers. The phase behavior of AOT in liquid alkane/water systems is already well documented. Indeed, the first report of the existence of the formation of microemulsions in a supercritical fluid involved an AOT/alkane/ water system. A The spherical structure of an AOT/nonpolar-fluid/ water microemulsion droplet is shown in Fig. 1. In the now well-known structure, it can be seen that the two hydrocarbon tails of each AOT molecule point outward into the nonpolar phase (e g., supercritical fluid). These tails are lipophilic and are solvated by the nonpolar continuous phase solvent whereas the hydrophilic head groups are always positioned in the aqueous core. 

However there is still a great discussion about the definition of their representative properties and even about the proper meaning of the word "microemulsion". Indeed such a name would indicate a dispersed system while microemulsions show the appearence of true solutions,i.e., of homogeneous systems. Since an essential requisite for the existence of a microemulsion is the presence of water (l), we think that a study of the fundamental properties of such systems should require the use of experimental approaches specifically apt to reveal "in primis" the behavior of water. Moreover,besides of course the hydrocarbon,being the other components necessary for the existence of a microemulsion amphiphilic compounds acting as surface active agents, also techniques suitable for the study of systems with a high surface-to-volume ratio, are requested. 

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