Acidity, separations through control

The emulsion overflowing from the nitrator enters the separator through a short section of pipe in which a special electrode is fitted for the measurement of the Redox-potential of the spent acid against a reference sample of mixed acid. The Redox-potential of the spent acid has a direct relation to the HNOj and HNOj content in this acid composed of lINOj-HNOj-HjO and can serve as a control on the extent that nitration follows the normal course without too many oxidation reactions and deviations from the normal course. It was first... 

Toofan, M., Stillian, J. R., Pohl, C. A., and Jackson, P. E., Preconcentration determination of inorganic anions and organic acids in power plant waters. Separation optimization through control of column capacity and selectivity, J. Chromatogr. A, 761, 163-168, 1997. 

Continuous Starch Hydrolysis. A commercial continuous converter installation for dextrose manufacture employing a continuous, automatically controlled step for the hydrolysis of starch is now in operation. A flow diagram of a modem commercial installation for continuous starch hydrolysis is shown in Fig. 13-4. The starch converter consists of an 8-in. coil, 677 ft long, which is fed by a high-pressure centrifugal pump from a continuous starch make-up tank equipped for automatic control of density (Baumd), level, and acidity. The level controller regulates the addition of 20 B starch suspension, the Baum controller operates the water valve, and a conductivity instrument controls the addition of acid. The head end of the converter coil has an entry chamber to separate non-condensables, and the feed is instantaneously heated with live steam through a jet heater. 

The hydroperoxide concentrate is fed to a second reactor where a selective decomposition takes place in the presence of dilute sulfuric acid and well-controlled reaction conditions yielding primarily phenol and acetone. The reactor effluent is passed through a separator to remove the water, acid, and salts followed by a series of fractionation steps to isolate both the phenol and acetone from undesired by-products. 

Use the apparatus detailed in Section 111,20. Dissolve 100 g. (123 ml.) of methyl n-butyl ketone (2-hexanone) (Section 111,152) in 750 ml. of ether and add 150 ml. of water. Introduce 69 g. of clean sodium in the form of wire (or small pieces) as rapidly as possible the reaction must be kept under control and, if necessary, the flask must be cooled in ice or in running water. When all the sodium has reacted, separate the ethereal layer, wash it with 25 ml. of dilute hydrochloric acid (1 1), then with water, dry with anhydrous potassium carbonate or with anhydrous calcium sulphate, and distil through a fractionating column. Collect the fraction of b.p. 136-138°. The yield of methyl n-butyl carbinol (2-hexanol) is 97 g. 

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