Podbielniak distillation column

Predictive method results are still compared to the Deaton and Frost data. It should be remembered, however, that while this study was both painstaking and at the state-of-the-art, the data were of somewhat limited accuracy, particularly the measurements of gas composition. As will be seen in Chapters 4 and 5, small inaccuracies in gas composition can dramatically affect hydrate formation temperatures and pressures. For example, Deaton and Frost were unable to distinguish between normal butane and iso-butane using a Podbielniak distillation column, and so used the sum of the two component mole fractions. Accurate composition measurement techniques such as chromatography did not come into common usage until early in the 1960s. 

For efficient separation of cyclodecanone from cyclodecane, a 60-cm. column of the simple Podbielniak type may be used. Removal of sebacil cannot be accomplished readily by fractional distillation, since cyclodecanone and sebacil have virtually identical boiling points. 

If no separation of isomers is required, as when the mixture is to be hydrogenated, the mixed esters may be obtained by distillation yield, 75-90 g. (71-85%, based on starting aldehyde). It is extremely difficult to separate the A2- from the A3-ester by fractional distillation, as the two boil only 7° apart however, by careful fractionation and refractionation through an 0.8 X 125-cm. simple Podbielniak column with partial-reflux head,4 it is possible to obtain 3 pure ethyl 4-ethyl-2-methyl-2-octenoate, b.p. 102-103°/4.8 mm., o 1.4478, and a nearly pure sample of ethyl 4-ethyl-2-methyl-3-octenoate, b.p. 94-95°/4.8 mm., ng 1-4393. 

When the checkers distilled the product through a simple type of Podbielniak column of 65-cm. length, with heated jacket and partial reflux head, the boiling range was 1°, 74-75°/6 mm., but the yields and index of refraction were the same as those reported by the submitters. 

The submitter used a 65-cm. Podbielniak type column equipped with partial reflux head.6 For distillation of the sodium-treated phenanthrene the checkers employed a 6-in. Vigreux column. For the fractionation of the dihydrophenanthrene, the checkers employed a 15-cm. spinning-band column obtainable from Nester and Faust, Exton, Pennsylvania. 

Purification. a-Methylstyrene was purified by distillation through a 6-foot, Heli-grid-packed, modified Podbielniak column under a reduced pressure of dry helium. Purity of the distillate was established by vapor phase chromatographic analysis, using flame ionization detection and an appropriate column. Sample purity generally ranged from 99.90 to 99.98%. 

Industrial analysis of hydrocarbon gases 25 years ago was limited almost to Orsat-type absorptions and combustion, resulting in crude approximations and inadequate qualitative information. The more precise method of Shepherd (56) was available but too tedious for frequent use. A great aid to the commercial development of hydrocarbon gas processes of separation and synthesis was the development and commercialization of high efficiency analytical gas distillation units by Podbielniak (50). In these the gaseous sample is liquefied by refrigeration, distilled through an efficient vertical packed column, the distillation fractions collected as gas and determined manometrically at constant volume. The operation was performed initially in manually operated units, more recently in substantially automatic assemblies. 

Irone (6-methyl-ionone, -trans-(a)-4/-[2,5,6,6-tetramethyl-cyclohex-2-yl]but-3z-en-2-one) [79-69-6] M 206.3, b 85-86°/0.05mm, 109"/0.7mm, dj 0.9340, n, 1.4998. If large amounts are available then fractionate through a Podbielniak column or an efficient spinning band column, but small amounts are distilled using a Kiigelrohr apparatus. The 4-phenyl-semicarbazone has m 174-175° (165-165.5°). [IR Seidel and Ruzocka HCA 35 1826 1952-, Naves HCA 31 1280 1948. Lecomte and Naves J Chimique Physique 53 462 1956]. 

Phenyl trimethylsilane (trimethylphenyl silane) [768-32-1] M 150.3, b 67.3 /20mm, 98-99 /80mm, 170.6 /738mm, d 4 0.8646. If the sample is suspect, then wash with H2O and distil using a Podbielniak Heligrid column or better a spinning band column. [7AC5 71 2923 1949, 73 4770 1951, 75 2821 7955]. 

The submitters used a 24-cm. jacketed Vigreux column for this distillation. The checkers used a simple type of Podbielniak column, 50 cm. in length, with heated jacket and partial reflux head after the last of the benzene had been distilled through the column, the following fractions were received ... 

Dissolve in Et20, dry (CaCl2), evap and distil through a short column. Distillation through a Podbielniak column led to decomposition. Store in the dark under N2, preferably in sealed ampoules. Even at -10° it slowly decomposes. [JACS 76 6054 1954. ... 

The product, which is sufficiently pure for the next step, contains at least 98% methyl hydrogen succinate as shown by titration or distillation through an 18-in. Podbielniak-type column. 

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