CORRESPONDENCE Synthetic Phenols for Resin Manufacture
had been added, the temperature was raised t o 330” C. The heat was shut off and the whole batch diluted by the rapid addition of water. This was such a radical idea that all my assistants believed it would blow up the plant; the first time we did it, I ordered everyone out of the building and turned on the water myself, full bore of 8 3-inch-diameter pipe but sprayed in a SIB: I was much interested in reading E. C. Britton’s article in the August, 1941, number of INDUSTRIAL AND ENOINEERINQ rain through a ring pipe under the cover. The ring pipe was perforated with several hundred */sinch holes. During this CHEMISTRY.I must, however, take exception t o his statement addition, rapid stirring of the pot was maintained and the heat on page 965, first column, fourth paragraph: “In the sulfonation was dissipated by the latent heat of evaporation of a considerprocess the raw materials are sulfuric acid, benzene, sodium, able portion of the water added. The fusion pot was covered, hydroxide and fuel. None of the reaction products can be reand the large quantity of steam was carried off by a 4&inchused in the synthesis.” As a matter of fact, I developed a process diameter ventilating pipe passing through the roof. for the New England Manufacturing Company which gave a Enough water was added to bring the concentration to a point high-grade product and operated a t great profit from about where practically all the sodium sulfite crystallized out and left September, 1916, until the Armistice in November, 1918, when in solution free caustic soda and sodium phenate. the plant was shut down and scrapped to save excess profit taxes. This slurry was sucked off into a large cooling tank having a I n this process several of the reaction products were re-used. slow stirrer. Here the crystals of sulfite grew to about the size So far as I know, this process has never been described in print. of granulated sugar, and the slurry was then run through a In the main it is what Britton calls the “classic process” but centrifugal machine to separate this salt. Since the filtrate was is different in many important respects from the usually accepted substantially caustic soda and sodium phenate solution, which procedure. First, sulfonation: At that time (1916) it was was treated first with pure carbon dioxide from the lime tank generally believed that oleum could not be used, and acid conas described and then finished by the addition of sufficient taining 98 per cent H8Ot was the grade usually purchased. sodium bicarbonate to bring about the complete separation of My process used oleum containing 20 per cent free SOa; this phenol. meant a large saving in the quantity of HzSO, required, since This phenol was completely separated from the sodium carthe free SO8 would combine with the water produced by the bonate solution by washing systematically with benzene, and reaction and thereby maintain the required concentration with the benzene was recovered for use again and again in a plain much less acid than if 98 per cent HaSOl had been used. The still heated by steam coils. sulfonation was carried out with very rapid stirring, and some The refiidue in the still was crude phenol, running 80 t o 85 of the old batch was always left in the sulfonator so that free per cent pure phenol, which was then rectified in a standard still SOa never came in contact with the benzene. This use of oleum to pure phenol. not only saved a large amount of HzSOI,but resulted in a correThe sodium sulfite from the centrifugals was used for convertsponding saving in lime required for the production of calcium ing the calcium benzene sulfonate into sodium benzene sulfonate, benzene sulfonate and in losses resulting from washing the for which purpose it worked as well as sodium carbonate. calcium sulfate residue because of the greatly reduced quantity I still have the complete and detailed operating instructions to be washed. that were developed for carrying out this process. The plant The lime used was calcium carbonate from the filters mainproduced about 20,000 pounds of pure phenol per day. tained in connection with the causticizers. It was added t o the benzene sulfonic acid in a closed tank so that the resulting pure HENRYHOWARD carbon dioxide was collected and used for neutraIizing the free Paradise Road Then the caustic soda from the fusion, as will appear later. Newport, R. I. sodium phenate was broken up, and the pure phenol was set free by the addition of sodium bicarbonate which constituted the make-up soda required in the process and which a t that time was the cheapest form in which soda could be purchased. It is Relation between Structure and Free well known that carbon dioxide will react with sodium phenate, Energy of Organic Molecules-Correction but this reaction is sluggish. I found that, by using the bicarbonate, the carbon dioxide in the nascent state reacted In this pnppr which appeared in the February, 1941, issue, quickly and completely t o produce pure phenol and sodium the first figure in the C=C equation (page 202, second column) carbonate solution; the latter was eventually causticized by should be +28,082 rather than +28.024, to be consistent with lime, concentrated as much as possible in a triple-effect evaporathe value +4437 for the first figure in the C-C equation The tor, and finalIy concentrated in an oil-fired, standard, caustic value of 2(C-C) was written as +8932 rather than +8874 in soda pot. Wlien enough caustic for fusion was in the pot and deriving the C=C equation. This discrepancy was caused by was concentrated to a boiling point of about 300” C., the sodium the use of data from another source in deriving equations for the benzene sulfonate, already concentrated as much as possible by olefins, but has no effect on the accuracy of the curves or the consteam, was run into the fusion pot with rapid stirring and strong clusions drawn. oil firing at such a rate that the temperature in the fusion pot The Erst figure in the C H equation was misprinted in the remained at about 300’ C. (never less than 280”). Under these sumqary (page 203) and should be -3844.5 rather than -3344.5. conditions no frothing occurred and the fire could be pushed t o P. F. BRUINSAND J. D. CZARNECKI the limit. When the whole of the sodium benzene sulfonate 1581
