D U R I N G t h e past two years a research prog r a m h a s been conducted atthis college relating to problems in the refining and improvement of products of Pennsylvania petroleum. Recently a petroleum refining laboratory was established where the work is to be c o n t i n u e d and expanded on a larger and more effective scale. One of the k s t problems studied was the composition and knock characteristics of straight-run Pennsylvania gasoline. T h e m o s t logical method for determining the composition, as well as the amounts of the various hydroc a r b o n s present, is fractional distillation. HowevRr, t h i s is not a simple problem, for the gasoline is known to consist of a large variety of hydrocarbons, each one being present to the The equations and relationships derived for fhe separation of complex mixtures are considerably more convenient than the usual stepwise method f o r calculating the plates in a .fractionating column, and it is believed they are suflciently accurate for design purposes. II becomes practically impossible to use the stepwise .method f o r unusually close separations in complex mixtures. Equations for the minimum number of perfect plates, and minimum reflux ratios are derived. Certain relationships are developed so that it appears that the separation of a complex mixture may be treated as the separation of a simple binary mixture of the key components, using the same ratios for the binary mixture as occur with the key components in the case of the complex misture.Fractionating columns, in agreement with the design indicated by these equations, are found to be effective in Pennsylvania gasoline. extent of onlya-few per cent. Since special equipment is needed for such a fractionation, it is always better if some method or data are available for the design of this equipment. DESIGN OF FRACTIOZJATIXG COLUU?;~Considerable information is available on the design of fractionating columns (1, 2, 5, 7). For binary mixtures, the graphical method for calculating the change in composition from plate to plate will readily give the number of perfect plates for any given separation, provided data are available on the vapor-liquid equilibria. For mixtures of more than two components, or for mixtures in which the actual chemical compounds are not readily identified, as in petroleum, the stepwise method of calculating from plate to plate by means of equilibrium data and material balances is used. This method was developed and used on the fractionation of petroleum by Lewis and co-workers (3,4). They introduced the conception of key components, which are the components between which the cut or fractionation is. being made.Since the fractionation of the straight-run Pennsylvania gasoline was intended to separate the constituents so that their identification might be possible, a degree of separation much greater than anything heretofore required was necessary.To get any significant separation of such a complex mixture, obviously a great number of plates (or their equivalent if a packed column is used...

Hydrocarbons can be readily oxidized in the vapor phase and noncatalytically to make chemicals under conditions of excellent temperature control when the reaction is carried out in the presence of a dispersion of fine inert solids DURISG the more than 20 years of work on vapor phase oxidation in this laboratory ( 2 ) : interest has centered on the development of a suitable reactor. the production and identification of chemicals resulting from hydrocarbon oxidations, and the mechanism of the oxidation reaction. Altogether; about 35 pure hydrocarbons have been studied.Eight different types of reactors (including open tubes, dense beds, packed columns employing highboiling inert liquids for temperature control in direct contact with the reactants, a transfer line reactor, and a three-stage alternate bed and void type of reactor) \vere built and evaluated > LIFT LINE

The Raman spectra of 172 pure hydrocarbons are presented both as reproductions of the original records obtained from a recording spectrograph and in tabular form as scattering coefficients and depolarization factors. Data are presented for 76 paraffins, 32 naphthenes, 29 olefins, 3 diolefins, 30 aromatics, and 2 other hydrocarbons. Direct comparisons of spectra are possible because a uniform Intensity scale has been used. The spectrograph employed VOLUME 19, NO. 10 Table I. Analysis of Known Hydrocarbon Mixtures Boiling Boiling Point, Deter-Point, Deter-Cor-Known mined Cor-Known mined rected Compo-Compo-rected Compo-Compo-Differto 760 Differto 760 sition,

Table V. Isobaric Heat Capacity as Function of Temperature and Pressure [Cp(TP), cal./mole-degree) Bars 100 150 200 250 300 350 50 11.82

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Although a number of workers have reported that certain bacteria and molds are capable of attacking hydrocarbons and mineral oils it is still not generally recognized how widespread is the occurrence of these organisms nor how great a variety of compounds of this nature may be attacked. Since S6hngen (1906) showed that some microorganisms possess the ability to utilize methane and Rahn (1906) described molds capable of attacking paraffin, there have appeared about thirty papers on the subject (cf. Hessel, 1924, and Tausson, 1929). Various gram-negative rods, particularly Pseudomonas, mycobacteria and micrococci have been described as attacking petroleum but there has been little effort made to compare organisms having this ability with bacteria that obtain their growth energy from the ordinary sources. Recently Bushnell and Haas (1941) have studied hydrocarbon utilization by various organisms and have found that Pseudomonas strains are most active whiJe certain species of micrococci and corynebacteria are also able to assimilate these compounds.The conditions necessary for attack on oils by microorganisms have been summarized by Tausson (1928) as follows: (1) presence of water with mineral salts;(2) a nitrogen source, such as the ammonium or nitrate ion; (3) free access of oxygen; (4) a neutral reaction and a buffer such as CaCO3 to maintain it.However, there has been little attention given as to what hydrocarbons are most subject to attack and the mechanism of their breakdown, although Tausson and co-workers (1934) have shown that some acids and unsaturation are produced in the bacterial dissimilation of crude and lubricating oils.The purpose of this work was to determine how wide a range of petroleum fractions could be readily attacked, to attempt to find which of several representative petroleum fractions were most subject to attack, and to isolate and characterize a number of organisms able to develop on a hydrocarbon medium. DEVELOPMENT OF CULTURES ON OILErlenmeyer flasks were prepared containing 0.5 g. oil, 50 ml. H20, 0.25 g.CaCO3, 0.25 per cent NH4NO3, 0.1 per cent Na2HPO4, 0.05 per cent KH2PO4, 0.05 per cent MgSO4, 0.02 per cent MnCl2, and traces of Ca, Fe and Zn. The flasks were inoculated with one gram of garden soil, incubated for a period of from 10 to 20 days and shaken twice daily. When considerable decomposition appeared as indicated by the emulsification of the oil and increased turbidity of the medium, 1 ml. of the mixture was transferred to another flask containing all the above ingredients except soil. After 2 to 3 transfers the breakdown of the oil proceeded faster and the period of incubation was shortened accordingly. Flasks were incubated at 20°, room temperature (23-26°), 30°, and 37°C. 169 on July 31, 2020 by guest

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A study of the oxygen absorption characteristics and the nature of the products obtained from oils oxidizing under controlled conditions has permitted the evaluation of a number of factors involved in lubricating oil deterioration.Investigation of selected fractions of a distillate stock has shown considerable variations in reactivity toward oxygen.The rate of oxygen absorption approximately doubles for each 100 C. temperature increase over the interval 140°to 180°C ., provided it is not limited by physical factors. The presence or absence of water vapor in the oxidizing atmosphere has little effect on the oxidation of one type of oil.The oxidation of certain oils can be reduced greatly by adding natural or synthetic inhibitors.