March, 1933
INDUSTRIAL AND ENGINEERIXG CHEMISTRY LITERATURE CITED
By ,Raoult's law, and substituting from Equation 18,
+
z3 = 23 y 3 = kna k12 Pa Equat,ing (17) and (19), ksb k7 = kiia kiz Ff = Aa Bb
(19)
++
+
295
(20)
Hence, there are two linear equations which can be solved for a and b, and the whole solution of the column follows. The labor of computation per plate between the two feed points is a t least twice as great as in ordinary cases. Taking these methods together, it appears that the complete solution of any column, no matter how complex, is possible to a degree of accuracy which is limited only by the available knowledge of the equilibrium relationships and of the plate efficiencies.
(1) Bahlke and Kay, ISD.ENQ.CHEM.,21, 942 (1929). (2) Brown, Souders, and Syland, Ibid., 24, 522 (1932). (3) Cope and Lewis, Ibid., 24, 498 (1932). (4) Fenske, ISD. EXG.CHEM.,24, 482 (1932). (5) FitzSimons and Bahlke, Am. Pet. Inst., Bull. 9, S o . 1, Sect. 111, 70-2 (1930). ( 6 ) Fortsch and Whitman, Ibid., 18, 796 (1920). (7) Leslie, Geniesse, Legatski, and Jagrowski, Ibid.,18, 45 (1926). (8) Lewis and Matheson, Ibid., 24, 494 (1932). (9) Lewis and Robinson, Ibid., 14, 481 (1922). (10) Murray, Ibid., 21, 917 (1929). (11) Selheimer, Souders, Smith, and Brown, Ibid., 24, 515 (1932). (12) Souders and Brown, Ibid., 24, 519 (1932). (13) TTilson and Bahlke, Ibid., 16, 115 (1924). RECEIVEDAugust 16, 1932. Presented before the Division of Petroleum Chemistry a t the 84th Meeting of the -4merican Chemical Society, Denver. Colo., August 22 t o ?6, 1932.
Sulfur Compounds Derived from Petroleum P. J. WIEZEVICH, L. B. TURNER, AND PERK. FROLICH Standard Oil Development Co., Elizabeth, X. J.
C
OXSIDERBBLE quantities of mercaptans and other sulfur compounds are being produced a t various refineries during the recovery of spent caustic obtained by treating sour crudes. The recovery operation generally consists in steaming the spent caustic, condensing out the steam, and burning the mercaptans and other compounds liberated (6). Table I (4) shows some of the physical properties of the aliphatic mercaptans available in the literature.
TABLE I. PROPERTIES OF ALIPHATICMERCAPTANS MEBCAFTAN
BOILINQPOINT
Methyl Ethyl n-Propyl Isopropyl n-Butvl sec-B&yl n-Amyl sec-Amyl
5.8-6.2 34.4-34,6 67.4-67.6 52.3-52.5 98.6-99.0 84.4-84.6 126.3-126.5 ll?.5-112.6
c.
PR~SEURE DENSITY25'/4'
Mm. 756 752 763 753 768 754 759.5 753
0.85991 0.83147 0.83572 0.80851 0.83651 0.82459 0.83750 0.82815
The caustic treatment removes mostly the lighter compounds, the heavier ones usually being converted to disulfides by means of doctor solution. A typical analysis of a mercaptan mixture available a t one refinery is as follows: hf ERCAPTaN Methyl Ethyl Propyl and higher
% ' by weight 30 53 17
These compounds can be separated fairly well by fractionation, and may be used as odorants, denaturants, pickling inhibitors, and raw materials for the preparation of other products described below. Moreover, the heavier mercaptans form oil-soluble lead salts. Ethyl mercaptan reacts with acetone in the cold and in presence of anhydrous zinc chloride or hydrogen chloride to produce acetone diethyl mercaptole (3) : 2CzHsSH
+ (CHa)zCO
(CzHsS)zC(CHa)z
+ HzO
When distilled a t atmospheric pressure, decomposition of this product occurs at about SO" C., the main compound formed probably being propylene ethyl thioether :
(CgHsS)&(CH8)2 = CzHlSH
+ C*H6SC(CHa): CH,
distilling over a t 105-115" C. Oxidation of acetone diethyl mercaptole (6)results in the formation of the well-known compound, sulfonal (CH&C(S02C2H&. THIOETHERS Although Sabatier and Mailhe (8) mention the use of cadmium sulfide as a catalyst for the conversion of mercaptans to thioethers, tests in this laboratory showed that the activity of this compound alone was not sufficiently high for commercial purposes. It was found that in presence of proper catalysts, ethyl mercaptan can be converted into ethyl thioether with good yields, according to the following equation : 2C2H6SH = CZH~SCYH) f HzS Using a cadmium sulfide-zinc sulfide-aluminum oxide catalyst a t 350" C., a conversion of 45-55 per cent to ethyl thioether is obtained per pass, about 5 per cent of the mercaptan being lost in the formation of side products such as ethylene, hydrogen, etc. When the ethyl mercaptan fraction from petroleum is used, a rapid poisoning of the catalyst results, so that it is necessary to carry out a preliminary purification by contacting the vapors with active charcoal, followed by a simple distillation, for removing the undesirable heavy ends. If an aluminum reactor is used with such an arrangement, a relatively long charcoal and catalyst life is obtained. The boiling points of the various aliphatic thioethers are shown in Table 11. Methyl thioether and ethyl thioether dissolve cellulose nitrate in presence of ethanol. The solutions compare favorably in various properties, such as viscosity, color, odor, and drying behavior, with such solvents for cellulose nitrate as are now in actual use in industry. Propyl thioether dissolves cellulose nitrate when mixed with methanol, as shown by the solubility chart in Table 111. Another possible use for the thioethers is as rubber solvents. The three thioethers which have been examined (methyl, ethyl, and n-propyl) dissolve rubber very satisfactorily. The boiling points of the ethyl and n-propyl ethers are higher
INDUSTRIAL AND
296
EN G I NE ER I N G
than that of benzene, but they form less viscous solutions of rubber. The fact that thioethers are solvents for both cellulose nitrate and rubber suggests the possibility of preparing a cellulose lacquer with rubber as a plasticizer.
C €1 E M 1 S T R Y
Vol. 25, No. 3
chloride. Ethyl disulfide dissolves sulfur monochloride without any evidence of reaction taking place. TABLEIV. PROPERTIES OF ALIPHATICDISULFIDES DISULFIDE
BOILINQPOIST
DENSITY
TABLE11. BOILINGPOIXTS OF ALIPHATICTHIOETHER~ THIOETHER
BOILINQPOINT
DEKSITY
c. 36.2
Methyl Methylethyl
0.854 (209) 0.837 ( 2 0 ' ) 0.836 (20')
66 91.6
Ettfylisopropyl Ethylisoprop yl Ethylpropyl Is0 ropy1 11. F?0p y 1 sec-Butyl Isobutyl n-Butvl Isoamyl
... ... ...
94
103 116 120.4 142 165 171 182 216
OTHERSULFUR COMPOUNDS 0.814' '(17') Using mercaptans or thioethers as raw materials, a number of other products may be prepared. For instance, by oxidiz0.836' '(10") 0.852 ( 0 ' ) ing ethyl thioether with hydrogen peroxide ( 7 ) in glacial 0.843 (20°/4') acetic acid solution, and with careful cooling, ethyl sulfoxide is obtained as a very fluid, high-boiling liquid (boiling point, ON CELLULOSE TABLE111. SOLVESTEFFECTOF THIOETHERS 88" to 89' C. a t 15 mm.) with a yield of 80 to 90 per cent: NITRATEWITH F'ARIOUS ALCOHOLS THIOETHER (CzH6)zS HzOz = (CzH5)zSO Hz0 ALCOHOL Methyl Ethyl n-Prowl
+++" +
Methyl 95 per cent ethyl 98 per cent isopropyl sec-Butyl a indicates t h a t cellulose nitrate diseolves; nitrate does not dissolve.
+
++ ++ (slight) -
-
- indicates t h a t cellulose
A number of resins such as p-coumarone, abietic acid, petroleum resin, m- and p-cresol-sulfur chloride resin, and xylenol-sulfur chloride resin are extremely soluble in thioethers; but vinylite 12, vinyl acetate, rezyl 12, and phenolsulfur chloride resin are dissolved slowly. Other uses for thioethers are as solvents for Grignard reactions, and as starting materials in the preparation of sulfonium compounds. For instance, dimethyl sulfate or methyl chloride reacts readily with ethyl thioether to give the corresponding sulfonium compound :
When these compounds react with alcoholic caustic soda, the very strong sulfonium bases are liberated:
+
(CzH5)z(CHa)S(CH,)S04 NaOH = (C2H6)&H3)S(OH) NaCHaSOd (CzH5)zS(CH3)C1 NaOH = (CzH5)2(CHa)S(OH)-I- NaCl
+
+
DISULFIDES At about 100" C. ethyl mercaptan may be oxidized with air in the presence of iron, copper, iron sulfide, charcoal, and other contact materials to produce ethyl disulfide with yields in the neighborhood of 90 per cent. The reaction may be written as follows: 2CzHsSH
+
' / 2 0 ~
= CzH5SSCzH6
+ HzO
+
+
Some uses proposed for this material have been as a plasticizer for pyroxylin and other finishes, and as a raw material for further synthesis. If the above reaction mixture is carried out without cooling, good yields of diethyl sulfone (?) result: (CzHdzS
+ 2&02
=
(CzHMOz
This material is a white crystalline solid melting a t 70" and boiling a t 248" C. It can also be prepared by oxidation of ethyl mercaptan by hypochlorite (9). The polysulfides can be prepared from ethyl mercaptan in fairly good yields. As an example, ethyl tetrasulfide (6) results when ethyl mercaptan reacts with sulfur chloride in carbon disulfide solution: 2CzHsSH
+ SzClz = (CzHs)zS4 + 2HC1
Oxidation of ethyl mercaptan with potassium permanganate (1) results in the production of ethyl sulfonic acid (C2H5S03H). Interest has been shown recently in the use of sulfonates as wetting agents, detergents, demulsifiers, etc. ACKNOWLEDGMENT The writers wish to acknowledge the assistance of W. Seaman, J. R. Huffman, and J. M. Whiteley, who carried out a large proportion of the experimental work on which the statements made in this paper are based. LITERATURE CITED (1) Autenrieth, Ann., 259, 363 (1890). (2) Barrowcliff and Carr, "Organic Medicinal Chemicals," p. 32, Balliere, Tindall & Cox, London, 1921. (3) Baumann, Ber., 19, 2803 (1886). (4) Ellis and Reid, J . Am. Chem. SOC., 54, 1674 (1932). (5) Klason, J. prukt. Chem., [2], 15, 214 (1877). (6) Mendius, Nutl. Petroleum News, 24, 42 (June 8, 1932). (7) Pummerer, Ber., 43, 1407 (1910). (8) Sabatier and Mailhe, Compt. rend., 150, 1570 (1910). (9) Wood and Francis, J. Am. Chem. SOC.,50, 1226 (1928).
As can be seen from Table IV, methyl disulfide boils a t The latter has been found to be a good rubber solvent, as well as a solvent for certain resins such as those produced from xylenol and sulfur
RECEIVED December 30, 1932.
SULFUR INDUSTRY IN 1932. The output of sulfur in the United States in 1932 dropped to less than one-half that produced in 1931. Shipments and exports showed smaller decreases than production, and stocks were reduced. Sulfur production amounted to 889,695 long tons in 1932, a decrease of 58 per cent, compared with the output in 1931 of 2,128,930 tons. The amount produced in 1932 was 1,669,286 tons, or 65 per cent, less than that reported in 1930, the record year. Shipments declined from 1,376,526 tons, valued at about
$24,800,000in 1931, to 1,108,112 tons, valued at about $19,900,000 in 1932, or over 19 per cent in both quantity and value. Stocks at the mines on December 31, 1932, had decreased to 3,031,000 tons, or 219,000 tons below the record reserve at the close of 1931. The new property of the Jefferson Lake Oil Company, Inc., in Iberia Parish, La., was put into operation the latter part of October. A production of 13,401 long tons was reported but no shipments were made.
118", and ethyl disulfide boils a t 153.5" C.
