Caustic distribution

Fig. 1. Illustration of a caustic. Different trajectories sample the probability distribution. If they cross each other in position space, the transport or probability density is not longer unique and the approximation might break down.

AH corrosion inhibitors in use as of this writing are oil-soluble surfactants (qv) which consist of a hydrophobic hydrocarbon backbone and a hydrophilic functional group. Oil-soluble surfactant-type additives were first used in 1946 by the Sinclair Oil Co. (38). Most corrosion inhibitors are carboxyhc acids (qv), amines, or amine salts (39), depending on the types of water bottoms encountered in the whole distribution system. The wrong choice of inhibitors can lead to unwanted reactions. Eor instance, use of an acidic corrosion inhibitor when the water bottoms are caustic can result in the formation of insoluble salts that can plug filters in the distribution system or in customers vehicles. Because these additives form a strongly adsorbed impervious film at the metal Hquid interface, low Hquid concentrations are usually adequate. Concentrations typically range up to 5 ppm. In many situations, pipeline companies add their own corrosion inhibitors on top of that added by refiners. 

The solvent is 28 CC-olefins recycled from the fractionation section. Effluent from the reactors includes product a-olefins, unreacted ethylene, aluminum alkyls of the same carbon number distribution as the product olefins, and polymer. The effluent is flashed to remove ethylene, filtered to remove polyethylene, and treated to reduce the aluminum alkyls in the stream. In the original plant operation, these aluminum alkyls were not removed, resulting in the formation of paraffins (- 1.4%) when the reactor effluent was treated with caustic to kill the catalyst. In the new plant, however, it is likely that these aluminum alkyls are transalkylated with ethylene by adding a catalyst such as 60 ppm of a nickel compound, eg, nickel octanoate (6). The new plant contains a caustic wash section and the product olefins still contain some paraffins ( 0.5%). After treatment with caustic, cmde olefins are sent to a water wash to remove sodium and aluminum salts. 

Conditions for hydrolysis (82) of the intermediate sultone mixture also help modify the ratio of alkenesulfonate to -hydroxyalkanesulfonate, distribution of alkenesulfonate positional isomers, and completeness of conversion. Caustic hydrolysis using a slight stoichiometric excess of base is employed to ensure alkaline conditions throughout the hydrolysis phase of AOS production. The rate of hydrolysis depends a great deal on temperature. The 5-sultone requires the most time for conversion to 4-hydroxyalkanesulfonate. P-Sultones and y-sultones hydrolyze so rapidly to 2-hydroxyalkanesulfonate and 3-hydroxyalkanesulfonate that temperatures below 100°C can be used. 5-Sultone completely hydrolyzes between 120 and 175°C in 1—30 minutes. The quaUty of the final product mixture is ultimately determined by the choice of conditions. 

The iron-sponge material is normally specified to have a size distribution with 0% retained on 16 mesh, 80% between 30 and 60 mesh, and 100% retained on 325 mesh. It is purchased with a moisture content of 20% by weight and buffering to meet a flood pH of 10. Because it is necessary to maintain a moist alkaline condition, provisions should be included in the design to add water and caustic. 

Chemical composition of packings. Today, a wider variety of different support materials is available from which to choose. Silica is still widely used, though preparative grades often possess a relatively wide particle size distribution as compared to polymer-based supports. One serious limitation of silica-based supports is the low stability of silicas to alkaline pH conditions, which limits use of caustic solutions in sanitization and depyrogenation. Polymer-based supports, which include poly(styrene-divi-nyl benzene)- or methacrylate-based materials, are widely available and have gained increased acceptance and use. Nonfunctionalized poly(styrene-divinyl... 

Table 2. D-statistic analysis of the ranking distribution of caustic soda production in seven major industrial countries, based on tonne per annum data [14] in brackets...

Natural barium sulfate or barite is widely distributed in nature. It also contains silica, ferric oxide and fluoride impurities. Silica is the prime impurity which may be removed as sodium fluorosilicate by treatment with hydrofluoric acid followed by caustic soda. 

Caustic-resistant corrosion inhibitors have been developed to help overcome this neutralization concern. However, these products must often be used at higher concentrations than carboxylic acid based inhibitors. Also, some caustic-resistant inhibitors tend to emulsify with water later in the fuel distribution channel. 

Extraction is a process for separating components in solution by their distribution between two immiscible phases. Such a process can also be called liquid extraction or solvent extraction. The former term may be confusing because it also applies to extraction by solid solvents. Since extraction involves the transfer of mass from one phase into a second immiscible phase, the process can be carried out in many ways. The simplest example involves the transfer of one component from a binary mixture into a second immiscible phase — extraction of an impurity from wastewater into an organic phase. In some cases, a chemical reaction can be used to enhance the transfer, e.g., the use of an aqueous caustic solution to remove phenolics from a hydrocarbon stream. 

Occurreace. IR-R. R (-Tartaric acid occurs in the juice of the grape and in a few other fruits and plants. It is not as widely distributed as citric acid or St- (-malic acid. The only commercial source is Ihe residues from the wine industry. The racemic acid is nut a primary product of plant processes but is formed readily from the dextrorotatory acid by heating alone or with strong alkali or strong acid. triewi-Tanaric acid is not found in nauire It is obtained from the other isomers hy prolonged boiling with caustic alkali. 

Delmau, L.H., Bostick, D.A., Haverlock, T.J., Moyer, B.A. 2002. Caustic-side solvent extraction Extended equilibrium modeling of cesium and potassium distribution behavior. Oak Ridge National Laboratory Report. ORNL/TM-2002/116. 

Distribution of cesium in the batch tests remained constant within experimental error in addition, no third-phase formation was observed. The solvent concentrations of calix[4]arene-bis-(rm-octylbenzo-crown-6) and l-(2,2,3,3-tetrafluoroproproxy)-3-(4-sec-butylphenoxy)-2-propanol remained constant within experimental error. Solvent degradation with irradiation was evidenced by a decrease TOA concentration decrease and an degradation product (4-ver-butyl phenol) increase in the solvent phase. No decline in extraction or scrubbing performance of the irradiated solvents was observed. The stripping performance of the solvent was seriously impaired with irradiation however, a mild caustic wash and replenishment of the TOA concentration restored the ability to strip the irradiated solvent. 

Delmau et al. (129) studied the self-association of fluorinated alcohols used as diluent modifiers for the selective extraction of cesium from caustic media by calixarene-crown ethers. They found that the salt distribution ratio is enhanced by the modifiers and explained this by a solubilization effect of the modifier due to its amphiphilic properties. 

Wilmarth, W. R., Mills, J. T., Dukes, V. H., Beasley, M. C., Coleman, A. D., Diprete, C. C., and Diprete, D. P. Caustic-side Solvent Extraction Batch Distribution Coefficient Measurements for Savannah River Site High-level Wastes, Sep. Sci. Technol. 38(12,13) (2003), 2637-2645. 

Delmau, L. H., Bostick, D. A., Haverlock, T. J., and Moyer, B. A. Caustic-Side Solvent Extraction, Extended Equilibrium Modeling of Cesium and Potassium Distribution Behavior, Report ORNL/TM-2002/116, Oak Ridge National laboratory, Oak Ridge, TN, May 2002. 

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