Studies in the Diphenic Acid Series. V

Abstract

Vol. 58 represents hydroxy acids of very high molecular weight. The investigation of this material will have to be deferred to a future time.The Solid Reduced Acids.-The solid reduced acids on recrystallization from acetone were obtained in form of colorless plates and had the properties of stearic acid.The melting point was 68-69°and the molecular weight was 283.7.The Unsaponifiable Matter.-The unsaponifiable matter from H-37 was a dark-colored viscous mass.The iodine number was 194. On combustion it gave the following values: found, C, 81.63; H, 10.76. An attempt to hydrogenate the substance with platinum oxide as catalyst failed and no hydrogen was absorbed. Reduction with the Raney nickel catalyst28 at a pressure of 2000 pounds for four hours also failed to yield a saturated compound.29 The substance recovered after this treatment had an iodine number of 136.The unsaponifiable matter from A-12 was a dark-colored thick mass with an iodine number of 226. It was possible to isolate 1.2 mg. of a digitonide from 1.51 g.30 of this unsaponifiable matter as described in a former paper.22 The digitonide gave a typical Liebermann-Burchard reaction.Further investigations of the unsaponifiable matter will be carried out in the future.The Wax Fractions.-The so-called chloroform-soluble wax has not been studied systematically except that the material extracted from strain H-37 was examined for (28) L. W. Covert and H. Adkins, This Journal, 54, 4116 (1932).(29) We are indebted to Dr. J. M. Sprague of this Laboratory for carrying out this reduction.(30) In the paper published in Z. physiol, Chem., 237, 40 (1935), through a typographical error the weight of the unsaponifiable matter used in this determination is given as 1.15 g. instead of 1.51 g.

A Comprehensive Analysis on the Reactive Dividing‐Wall Column, its Minimum Energy Demand, and Energy‐Saving Potential

“…The corresponding flowsheet of the decomposed DWC is displayed in Fig. 2 c. The minimum vapor demand in each of the three conventional columns may now be calculated with the wellknown Underwood equations [37], assuming an infinite number of stages, constant relative volatilities, and constant molar overflow.…”

“…The minimum vapor demands of the conventional distillation columns of the RD sequences are calculated with the Underwood equations [37]. Halvorsen and Skogestad [43] give a good overview of the Underwood equations and a procedure to solve them.…”

Minimum vapor flows in a distillation column with a sidestream stripper

“…The method presented is based on Underwood's equations (Underwood, 1946(Underwood, ,1948. Therefore, constant relative volatilities and molal overflows in each column section are assumed.…”

“…In column 2, the separation B/C takes place. Therefore, the root of eq 2 we have to use in (1) satisfies «ß > £2 > 1 (Underwood, 1946). Throughout the rest of this text, the various roots of eq 1 are ordered so that £3 > £2 > £v Consider the first column and assume that the liquid sidestream (stream L3 in Figure 2) leaves the column one or two trays above the side-stripper tray.…”

“…Therefore, the composition of stream L3 coincides approximately with the pinch composition. We know that the latter satisfies the equation (Underwood, 1946) ^ ,3 "bXb,3 Xc,3…”