Phenol RICHARD L. KENYON Associate Editor
in oollaboration with
N. BOEHMER Mo-nto
Chemical Cornpony, St. Louis, Mo.
Sulfonation S p t e m , Monsanto, Ill., Phenol Plant
T
HE bistory of phenol Production in the United States has
been one of great fluctuation, d e c t e d particularly by warn. There have been rapid shiftsfrom exceae supply to shortage,with a t a m i v e effect on the industry, as can be seen from tracing the history of this segment of the chemical industry. Phenol was first discovered by Runge, in 1834, when he WOlated it from ooal w. It remained d natural product for nearly a half century until Wichelhaus realbed the value of the reaction, dhovered in 1826 by Faraday, by which aromatic sulfonic d d s could be fused with alkali to yield the hydroxy cornwunds. This was aonlied of 8. . .. Drimarilv to the DreDaration haphthol, imponant in the dye indus&, wheo it was first brought into commercial use. but durioa the 1890's svnthetic phenol was made in Germany, in&ifi&t quantiti;, by the alkali fusion of beruenesulfonic acid. During the Boer War, England placed an embargo on phenol, whiah c a d a shortage on the wntinent. As a result, the F. Rsschig worke, at Ludwipshafen, Germany, went into the manufacture of the synthetic product on a large scale. HoffmannLaRoohe, W e , Switzerland, ala0 began producing about this time, mostly for the pharmaceutical industry. In 1913 the only production in the United States was of the natursl product from coal tar, hy the Bsrrett Manufacturing
Company, now the Barrett Division of the Allied Chemical and Dye Corporation. Medical usea represented the greatest consumption, although the new phenol-formsldehyde reains and a few chemical compounds in commercial production used phenol as a starting material. Prewar consumption of phenol was about 5,000,000 pounds per year (844). Thomas m o n had built a plant which was producing synthetic phenol for the manufacture of phonograph records, but no othera were operating at the outbreak of the war. The supply of picric acid and dyes ww cut offwith the beginning of World War I. throwing tbis country on ita own remurces w i t h the result that prductionapruy up rapidly. By 1915, Barret1 wasmakingthesyntheticproduct inits Frankford, Pa.,plant. Solvay ProoessCompany, at Syracuse, N.Y., and Dow Chenucal Company entered the field in that same year. In the follouing ye-, Monmnto Chemical Company, MilwaukRe Coke and Gas Company, and the Commercial Acid Company became active in phenol manufacture. The last company w m acquired by Monsanto in 1917. The largest unit, with B deaigned capacity of 35,000,000pounds per year, was begun by Barrett but remained un6nished because of the end of the war. Consumption had reached 72,000,000 pounds per year at the time the United States entered the war (844).
1446
INDUSTRIAL AND ENGINEERING CHEMISTRY
August 1950
iB
Wien hostilities endrd iheie T\ as on hand a large government supply and no demand. Plaiits I? ere dismantled, and the industry seemed to have fallen apart. But by 1922 the picture had changed again: because of the growth of the manufacture of phenol-formaldehyde resins, the surplus of phenol had disappeared. Heyden Chemical Company began producing the next year. Monsanto constructed a plant at Monsanto, Ill., which miit into operation in 1923. Dow installed the process for the manufacture of phenol from chlorobenzene in 1924 ( 2 ) , and the Bakelite Company began producing at Painesville, Ohio, continuing until 1928 (68). By 1938, almost all thp synthetic phenol production in the I-nited States was operated by Don, and Monsanto (68); the total capacity was near 90,000,000 pounds. In 1940 Durez Plastics and Chemicals, Inc., began operating its new 15,000,000pound-per-year plant (1) employing the Raschig, or regenerative, process, and Barrett put a sulfonation process plant into operation, The war stimulated production once again. The Catalin Corporation installed a small unit in 1942, which is no longer operating. Reichhold Chemical Company’s sulfonation process unit in Tuscaloosa, Ala., went into operation late in 1943 (19). The Solvay plant produced for a few months in 1943-44. General Electric built a plant a t Pittsfield, Mass., which began production by caustic treatment of chlorobenzene in 1946, and Heyden acquired an ordnance plant in Memphis, Tenn., in that year, ~ \ i t hthe intention of manufacturing phenol but never made phenol in that plant. Once again the end of hostilities left an excess of phenol production capacity, but within a f p w months its use in the manufacture of a number of products passed the demand and expansion was resumed. I n 1947, capacity was increased by 42,000,000 pomids to a total of 300,000,000. Nobell Resins Company, .lzusa, Calif., built a sulfonation process plant of 3,000,000-pound capacity in 1948, when they could not procure phenol on the West Coast. It went into operation in January 1949, but closed nfter 2 months because of the market price a t which phenol be-
T.IRLT:I.
SATURAL AND SYKTHETIC PHENOL-NEW
SUPPLY
1447
TABLE 11. SYNTHETIC PHENOL-CAPACITYAND PRICE^ As
1913 1914 1915 1918
Rateda 0
( I n millions of pounds) Capacity Producers InoperaNumber, tiveb NetC Active
9:
100 e
1922 1923 1924 1925 1926 1927 1928
1: 20 e 20 e 20e 20e 14 e
1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950
90 90 118 118 154.5 250.5 255 255 258 300 2802 3402 4102
...
... ...
... ... ...
... ... 0 0 0 0 0 30 30 30 30 30
5 132 160
Price, U.S.P $0.113 0.203 1.271
... ... ... ...
0 1 5 6
0.53-0.30
...
0
... ... ... ...
...
4 6 6 6 5 4
0.176 0.37 0.28 0.224 0.197 0.169 0.15
90 90 118 118 154.6 220.5 226 225 228 270 275 208 2508
2 2 4 4 5 7 6 6 6 6 6 7 6
0.145 0.138 0.129 0.123 0.125 0.106 0.105 0.105 0.106 0.114 0.12 0.125 0.155
.
.
I
a 1938-, as developed from announcements and communications. rated signifies expected and as engineered to obtain whether operative ‘or not. b Rated capacity less than shown to be obtainable subsequently: does not include capacity inoperative because of benzene shortage. the Memphis, Solvay, and GE plants make up the totals. Realizable hapacity (see b ) . +eludes the GE plant t o the capacity obtained. d Producers operating! net capacity”; this excludes the MeAphis plant 1943-48; excludes the Solva plant all years. e Approximate only; trade estimations are various, both {igher and lower than cited here. 1 Data and footnotes through 1947 reproduced from Chem. Eng. A‘ews (as). 2 Based on published figures and private communications. Memphis and Solvay plants excluded. year-end estimate 1950. 3 Based on extrapolation’from U. S. produc6ion figures for first quarter,
came available. Since that time no new companies have entered the field, although some have expanded plant capacities. Bakelite has indicated plans to open a plant employing the regenerative process in Marietta, Ohio, probably late in 1950. At the present time Dow and Monsanto are the leading producers. Others contributing significant quantities include Barrett, Reichhold, and Durez.
AND EXPORTS‘
(In thoiisunds of pounds) Ne,
1913 1914 1916
Supply, Net 9,346: 11,383
Total b 1,000;
woo
PI oduction Synthetic 0
mood
1918
100,599
106,794
100,00Od
1922 1923 1924 1925 1926 1927 1928
1,559 3,208 11,021 15,089 8,935 8,654 11,205
1,286 3,311 10,522 14,734 8,691 8,041 10,227
0 1,300 8.000 12.000: 7.000 6,000 e 8.200 e
TABLE 111. PHENOL CONSUMPTION Natural Imports’ Exports 1,000d 8,346 ... i,oooa 8,393 . .. 3,106 7,000
283
6,478
1 286 2’000b 2:500; 2 700 1:700: 2 000 2:000b
496 130 550 355 244 613 978
223 233 51
... .. . . .. ...
1936 47,537 48,724 36,7001 12,000: 71 1,258 1937 65,722 65,690 50,900/ 14,800 32 ... 1938 44,548 44,548 30.7601 13,8OOc . 66,519 68,577 53,0001 l5,60OC ., 2,058 1939 1940 91,851 96,155 72.188 23,968 .. 4,304 1941 111,861 115,047 92,922 22,125 , 3,186 127,016 146,125 127,632 1942 18,493 ... 19,109 1943 164,129 194,967 181,347 13,620 . 30,838 1944 178,686 201,993 173,141 28,852 ... 23,307 1945 188,260 205,112 181,640 23,472 . . 16,852 179 143 203,829 1946 183,856 19,974 ... 24,686 247,’913 268,460 245,0OOc 1947 23,6OOc 1 20,558 267,280 297,3382 274,274 23,064 . . 1948 30,058 1949 201,602 224,5442 207,969 16,176 22,942 Dyes & Synthelzc Chemicals; U. S. Tariff Commission 1918-46. 1947 preliminary. b Foreign Commerce & Nauigation; all grides of pLeno1i.e., 30%” data obtained from analyses in various tariff reports‘ see also Phenol, *ariff Commission, 1928; 1936-40 Commerce Statenlent 3865. Foveign Commerce & Navigation; 1918-26, Phenol, Tariff Commission 1928: 1913-37, Report No. 131, 2d series, p. 15, Tariff Commission. d Ap: proximate only. e Approximate and based upon statements made In annual tariff reports and the trade. f Approximate. natural phenol estimated from quantity of t a r distilled and synthetic phenol estimated by difference. 1 Data and footwtes through 1947 reproduced from Chem. Eng. News
. .. .. . . . . . .. .
(y,if]S.Tariff Commission, Sun. O w . Chemicals, Rept. 164, 2nd series.
(Distribution of consumption in the United Statesa, 1944, exclusive of military requirements)
% Phenolic resins and adhesives 66.0 Manufacture of chemicals 7.2 Medicinals including salicylates 8.1 Petroleum bhemicals and petroleum refining 6.6 Disinfectants and insecticides 3.6 Plasticizers 2.8 Toluene extraction 2.7 Dyes and inks 1.5 Miscellaneous uses and small orders 1.5 a Data from information issued by U. 6. Department of Commerce on allocations of phenol.
The mushroom growth following World War I1 was accounted for partly by foreign demand, but other major factors included growth of the plastics industry, waterproof plywood production, and the use of phenol in petroleum refining. The development of the use of pentachlorophenol for wood-treating, slime and algae suppression, and tanning and the discovery of the weedkilling properties of 2,4-dichlorophenoxyacetic acid were major contributing factors. FUNDAMENTAL CHEMISTRY AND COMRf ERCIAL PROCESSES
Phenol can be prepared by means of any of a number of organic chemical reactions. Considerable attention has been given to the manufacture of phenol by the direct oxidation of benzene with air, using a great variety of metallic catalysts ($1)iodine (I?‘), and oxides of nitrogen (5, 6 ) , as well as noncatalytic processes
1448
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 42, No. 8
( 7 , 20, 21). The inclusion of small amounts of organic materials of diverse types has been found t o improve the reaction (11, 18). However, only three methods have been put into commercial application. They are:
Of these feactioiis, I'i,crc I is t.ti!si'ul and is discarded t,o the, obnoxious vapor cond(~ii-ol~. which is a water siphon absorber. The residual ~ l u r r y of sodium sulfate,, $ t i dium benzene-sulfonate, and possibly sonit' acid is pumped hy means of an Evertiur centrifugal pump to the final adjusting t a n k , where sodium hydroxide solution is added t o make the slurry alkaline. Although it) is 1101 necessary that thehe final adjusting tanks lw lined, their const,rurtion is similar to that) of the neutralizing tanks in order to furnish stantii)!. capacity. The main product is now a slurry of sodium sulAcidification Tank and Tower fate in aqueous sodium benzenesulfonate solution. Phenate solution i b pumped t o top of tower, u p p e r r i g h t , through vertical pipe, It is pumped by cast-iron centrifugal pumps t o IeJt c e n t e r ; after falling a% spray and absorbing sulfur dioxide, solution returns to tank, lower I t f t , through pipes leading from lower end of tower steel agit,ated tanks horn which it is fed i o t!w centrifuge syst'em. Centrifugation is accomplished by a batt,ery of three solid-bowl continuous W I I second unit has cooling coils and a cooling jacket. The third trifuges. The first two effect the niajor seDaration of sulfate from-the solution. The separated sulfate, slurried with a sinall and subsequent units have steam jackets for the application of heat. quantity of water as a wash, is passed through the third v(,tiiriBoth benzene and oleum are constantly circulated through fuge. The solution from the first two centrifuges goes to thc overhead wrought-iron pipe lines with drawoff connections t o thc evaporators; solut,ion from the third is sent to the sulfite iiiixclr t'o make up the sulfite slurry used in neutralization. The n.a?hvti reactors. Recording flow controllers are used here, and the feed sulfate from the third centrifuge is kiln-dried for sale. Tho t11.yis regulated in a proportion which will allow sat,isfactory control of the initial reaction in the first unit. The rate of feed cont,rols ing operation is carried out in a brick-lined, oil-fired rotary liiln. The product is shipped in bulk. the rate at which the reaction mixture flows from one unit to the next, and the temperature is set at a level which will give optiEvaporation. The solution of beiizenesulfonate ( S a 135) mum operating condit,ioiis in each unit and will ensure completion which comes from t'he first two centrifuges is pumped to stwl of t,hereaction. st'orage tanks. From storage thc solution goes t o t,he cvapoixNeutralization. The sulfonated product is fed into a tors. Standard cone-bottomed evaporators wit,h external hrai c w are used. The solution enters the body of the evaporator t hcn neutralizer system. This system consists of preliminary circulates through a system of three tuhular heat exchangtJt,sa i i d neutralization tanks, each of approximately 5000-gallon back to the body. The exchangers are two-pass, multitukic, capacity; these are connected by valves to a line in which t h c steam heated units, each connected with a separate centrifugal sulfonation product circulates from storage. The tanks are of circulatory pump. Vapors from tho craporators pass throuyli steel with lead lining and acidproof brick inner lining. They are a scrubbing tower ( S E ) with a countcrcurrcnt flow of 2 5 5 aciucsagitated by means of cross-blade stirrers. ous caust,ic in order to remove any phenol which might h a w twcu The agitators have three single cross blades at intervals on the formed and carried out. The drawoff fi,om t>hebottom of thc shaft; the bottom blade is not rigidly attached to the shaft but is attached to the top blade by means of two heavy bronze chains cvaporator is pumped to a cone separator, where most oi' t h t x sulfate is drawn off continuously from the bottom of the w p a attached near the blade ends. Thus it is able to move up and down on the shaft. If agitation is st,opped, solids settle out, rat'or, by means of a centrifugal pump, and is returned t o 1 1 i v tanks feeding t,he SaBS-sulfate slurry to the centrifuges. Tti(> making a nearly solid sludge. When agitation is resumed, the concentrated solution overflows f m n the separator to storsg-. bottom blade is pulled out of the sludge by the chains and in turning cuts its way down to cffcct stirring of the sludge back into the \There the small amount of sulfaLe remaining is reniovcti lly slurry. i'urth.er settling and is interrnitt~ntiypumped aa.ap. h(91.
Au&
1950
I N D U S T R I A L A N D E N G I N E E R I N 0 C H E M I S T:RY_,
jli,,,i
’..,..,”,.-,
1453
;
.
-
Fusion. Specially fabricated cast-iron pots are used in carrying out the fusion. These pots have vertical sides with dished-up bottoms which cause 5thrather than elongation at the temperature of operation. The agitators are of the anchor type, made of special cast alloy steel. The pote are set in brick, with the tops flush with the level of the operating platform. A dam, or rim, is built up ahout 3 i n c h around the top of the pot in order to handle any material which may accidentally boil over. Each pot is directly 6red by six burners which can he operated with either natural gas or oil, thus safeguarding agsinst limited fuel supply. Ebdium hydroxide is pumped by a nickel centrifugal pump through nickel pipe limes from the caustic plant 88 a 70% caustic soda solution. It is stored in a ateam heated, insulated tank near the fusion pota, where it is lield in a molten state. I n preparation for fusion, a measured amount of caustic is run into a fwwn pot and evaporated, without agitation, nearly to dryneas, as indicated by B sharp increase in temperature near 300’ C. Agitation of the molten caustic is then s t a h d and feeding of the NaBS solution ia hegun. The NsBS solution is pumped from a steel measuring tank to the fusion pot at a metered rate by means of a centrifugal pump. The rate of feed is regulated so as to maiotain the fusion mass in a molten state. Mmt of the reaction takes place as the NaBS solution is fed in, hut d d i t i o d heating is required, after sll the solution has heen edded, to drive the reaction to completion. when the fusion is completed, the material is drained through a aide nozzle in the pot which ia closed with a plug valve. To this plug d v e is attached a nipple closed with a cap. In tapping out a batoh, the cap is first removed, then the plug valve is opened. Usually, some of the fusion ma88 solidifies in the outlet nozzle
ConbBottom Tanks for Separating Crude Phenol from Sulfite Mother Liquor
Figure 3.
Flow Sheet for Recovery of By-product Sodium Sul6te
behind the plug valve and must he washed to the quencher beforethebatchwillflowout. The quenching operation consiste of running the fusion maaa into an agitated tank containing a weak solution of d u m phenate, which is the wash water from the washing of sulfite filtered from the quenched fusion slurry. No cooling or heating is mcessry and the steam generated paases out the stacks, which are equippea with eeparators to collect entrained matpoial and return it to the quencher. The multiug slurry of d u m sulfite and sodium phenate is run to automatic, 8ucOeSaive batch centrifugal separators. These separators (1B) comist, fundamentally, of a basket on a horizontal shaft. slurry is fed inside the basket until it is filled with solid. The cake is washed once with water, after which the machine automatically digs it out. The solid separated in centrifugation is sodium aulfite and is used in the earlier neutralistion. The oentrifugate, which ~9 sodium phenate solution, goes next to acidification. The wash water is uaed for future quench solution. Phenol Isolation and Reaninp. The sodium phenate solution is held in three receiving tanka. As the solution contains a mall amount of d u m hydroxide, a portion of it is fed to a castiron absorption tower packed with steel ringa where it takes up the small amount of phenol stripped from the sulfiteslurry which is a by-product of final acidiiieation. The solution returns to the receiving tanks. Thence it paasea to either of two agitated steel tanks, where there is d d e d the weakest rater fraction from the phenol relining stills; then it is pumped to the acidification tanks. The solution is cooled by meam of heat exchangers. From the acidification tanks the solution is circulated through acidification towers, one of which ia connected to each feed tank. The acidiiication towers are vertical steel cylinders lined with lead and acidproof brick. Sulfurdioxide from the neutralizers is admitted through the side of the tower at a point about halfway up from the bottom. The solution circulated from the acidification tanks entera the top of the tower through a nozzle which gives a fan-haped distribution to the spray. The solution ahsorbs sulfur dioxide and flows out the bottom of the tower to the acidification t9nk. Unabsorbed sulfur dioxide is discharged near the top of the tower and passes to the obnoxious vapor condenser for disposal. The solution from the tower neutraliees the phenate solution flowing into the tank causing it to separate into two p h m -
c
a454
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Vol. 42, No. 8
q NEB TECHNIflllES 11 CHF1WICAL LITERATURE
I
I
I I
Presented before the Division of Chemical Literature a t the 116th Meeting of t h e American Chemical Society, S e p t e m b e r 1949, A t l a n t i c C i t y , 3-.J .
Conventional and Bechanized Search Hethods S. W. COCHRAB' U . S. Patent O f i c e , Washington, D . C .
J. W. PERRY Massachusetts Institute of Technology, Cambridge, Muss. T h e scientific and technical information stored in modern libraries is a peculiar
INEERING CHEMISTRY
1455
heating coils which are tested before each car loading. Cars are designed t o unload from the top as well as through bottom outlets. Phenol is also shipped in galvanized iron, black iron, and lacquer-lined steel drums and in 23-gallon tins. Storage tanks are of steel or nickel-clad steel. In handling phenol, care must be taken to avoid the inclusioii of water. The product is specified according to crystalliziiig point. As Figure 4 shows, even traces of water have a marltcd effect on crystallizing point. CHEMICAL COhTROL AND SPECIFICATIONS 6
I
39 +
Sodium Sulfite. Sulfite liquor (Figure 3) from the stripping. column is collected in an adjustment tank where caustic soda solution is added to make the liquor distinctly alkaline. It is then passed to a cone-bottomed evaporator to which heat is furnished by two external steam heated shell-and-tube heat exchangers. The slurry from the bottom of the evaporator is run to a conebottomed separator from which the supernatant liquor is returned to the evaporator, and the thick slurry is fed to a basket centrifuge, The centrifugate is returned to the adjusting tank and the wet solid sulfite is carried by screw conveyer to a rotary dryer and thence to a rotary cooler. Air drawn through the dryer is passed through a dust collector before being blown into the atmosphere. The dust is returned to the wet centrifuge cake conveyer entering the dryer. After cooling, the sulfite is passed over a vibrating screen and all material passing through a 10-mesh sieve falls to the finished product bin from which barrels and bags are filled. All material retained on 10 mesh is run through a hammer mill and returned to the screen. MATERIALS OF CONSTRUCTION
In general, equipment throughout the plant is steel or cast iron. At points where wet sulfur dioxide is handled, Tobin bronze, lead, or Haveg is used. Sodium benaenesulfonate solutions, containing small amounts of sulfur dioxide, are handled in Everdur. Nickel is used in pumps and pipes for caustic solution. Stainless steel 304 is used for the hot slurries of sodium sulfite, which has both an abrasive and corrosive action. The centrifugal separators are of stainless steel for this reason. Cast iron gives satisfactory service where sulfuric acid is used, as in the sulfonators. It is well knoun that iron causes discoloration of phenol. For this reason, nickel is used in handling the finally distilled product, beginning with the condensers. Steel may be used for storage and shipping where a water-white product is not required, MATERIALS HANDLING
Almost all materials are pumped as liquids or slurries. I n feeding raw materials, a constant circulation system, which provides a constant head, has proved most satisfactory for benzene and sulfuric acid. The same has been applied to the sulfonation reaction product which is fed into the neutralizers, Wet and dry sulfate and sulfite are moved by screw conveyer. Dry sulfite is also handled by conveyers of the enclosed scraperchain type, which has the advantage of being capable of elevating material as well as moving it horizontally. Phenol is shipped in steel tank cars of 4000- to 10,000-gallon capacities for the ordinary product and in similar nickel-lined cars where a water-white product is specified. All cars contain
U.S.P. phenol from the distillation column is checked hourly and must have a minimum crystallizing point of 40.6’ C. Phenol for shipment is specified as material for steel containers and tank cars or material for galvanized or lacquered drums and tins. The standards are: Property Color Melt color Solution in 10% \-.nx Crystallizing point Dintillation range
Regular Wliite t o light pink APH.4 150,max. Clear and colorless
Water-White White A P H A 10, inax. Clear and colorless
40.6’ C., inin.
40.6O C.. inin.
?O
C . inax. (first droll
180’
C., min.)
2 O
C. max. (fi,rst d r o p 180’ C., min.)
LITERATURE CITED
(1) Anon., IND. ENG.CHEM.,SEWS ED., 18, 921-(1940). (2) Anon., C h e m . Eng. S e w s , 20, 1510 (1942). (3) Aylsworth, J. W., U. S.Patent 1,213,142 (Jan. 23, 1917).
(4) Barbet, P. A , , U. S.Patent 1,459,081 (June 19, 1923). (5) Bibb, C. H., Ibid., 1,547,725 (July 28, 1925). (6) Bibb, C. H., and Lucas, H. J., IND. ENG.CHEW,21, 635 (1929). (7) Bone, W. A., and Newitt, D. M. (to Imperial Chemical Industries, Ltd.), U. S. Patent 2,199,585 (May 7, 1940). (8) Bull, H., Ibid., 1,247,499 (Nov. 20, 1917). (9) Crawford, R. M., Chem. Eng. N e w s , 25, 235 (1947). (10) Dennis, L. M., U. S.Patents 1,211,923(Jan. 9, 1917); 1,212,612 (Jan. 16, 1917); 1,228,414 (June 5, 1917); 1,229,593 (June 12, 1917). (11) Denton, W. I., Doherty, D. G., and Krieble, R. H., IWD. ESG. CHEM.,42, 777 (1950). (12) Groggins, P. H., “Unit Processes in Organic Synthesis,” 2nd ed., New York, McGraw-Hill Book Co., 1938. (13) Guyot, A,, Chimie & Indztstrie, 2, 879 (1919). (14) Hale, W. J., and Britton, E. C. (to Dow Chemical
