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Industrial Wastes
RUBBER INDUSTRY GEORGE M. HEBBARD, The Davidson Corporation, Baltimore, Md. SHWPARD T. POWELL, Professional Buildiog, Baltimore, Md. R. E. ROSTENBACH, OBce of Rubber Reserve, Washington, D.
C.
b T h e production of synthetic rubber in t h e United installed capacity, including H E production of States is desdbed, both before the war and after the way 705,000 long tons of GR-S, synthetic rubbers of program was initiated. The principal types of rubber 60,oW long tons of Butyl, all typea in the United produced by the induetry and methods employed for and 40,000 long tons of neoStates until 1940 repremanufacture are outlined. By-product wastes f m m the prene. Because of operatsented only a moderate production of synthetic rubber and from t h e manufacture ing improvements this effort by several of the of the principal material< employed in t h e processes a m program later demonstrated larger chemical, petroleum, . discussed, and tables are presented tbat show the deet that more timu 1,000,000 and rubber companies to of these wastes on operating plant effluents. The raw long tons per year of the develop pwsibilities along materials necessary for production of synthetic rubber three types of rubber could their particular lines of re(butadiene and styrene) are given. Methods adopted be produced. In all, fiftysearch and development. for recovery of partially or wholly processed materials t h r e e p l a n t s involving Thiokol waa introduoed from waste waters as well a s treatment facilities now forty-nine industrial organicommercially in 1929, but installed are described. The design of treatment facilities zations were constructed its production attained only for the United States is touched upon and c b e m i d methods for improving modest figures. Neoprene Government rubber proplant effluents are outlined. Flow sheets illustrate t h e entered the picture in 1932 gram. These include not discharge of liquid wastes into plant sewerage systems, and became a valuable rnbonly the copolymer units, and the location and character of treatment faoilities her specialty, although prostyrene plants, and butafor removing objectionable eonstituents f m m waste duction before the war diene plants utilizing both tiatere. Disposal of recovered materials is discussed. Exreached only a few thonalcohol and petroleum for penditures are outlined that have been made for waste feedstocks and butylene ssnd tons annuslly. Not treatment facilities during t h e relatively short period i n feedstock units, but also until early 1940 was an which the American synthetic rubber industry has existed. necesaarv catblvst. all-purpose rubber, such _ .chemid, and solvent operations. as GR-9, considered on a commercisl scale, although RUBBER TYPES AND PROCESSES extensive development had been conducted in the field of diene copolymers following initial German production of Buna S in The general types of rubber produced in the chemicsl rubber 1935. program are repeated here: On June 25, 1940, the Reconstruction Finance Corporation Act wae amended to authorize the R.F.C. to create corporations GRS Inoludes all-purpose GRS Copolymer of butadiene and for the purpose of acquiring strategic and critical materials aa types. such 8 8 GRSAC, styrene stab&ed with defined by the President. On June 28 of the same year the GR-510. GR-S Black 1. antioxidants President designated rubber m a strategic and critical materid, eta. (4) GR-I Butyl for pneumstio and Copolymer of isobutylene and Rubber Reserve Company was created by the Reconstruction general inner tube spplioasnd isoprene Finance Corporation. The original purphse of Rubber Reserve tions. coatinpa, etc. Company was to buy and aeoumulate a stock pile of natural G R M Neoprene for special applica- Polymer of chloroprene rubber aa a safeguard against possible war in the Far East. The tions, such 8s oil and solvent. resistance, foam later activities of Rubber Reserve, m explained in their reports sponge. etc. (4, have been predominately concerned with the Government's synthetic rubber program. These activities have been unique G R S is first pioduced aa a latex by emulsion copolymerization in comparison with activities of other government agencies, in of styrene and butadiene with tallow or other stearate oil-base tbat Rubber Reserve haa had the direct responsibility, from the soaps, and coagulated to crumb by one of a number of coagulating date of its inception, for the formulation, correlation, and operachemicals. GRS-10 varies from G M in that a rosin'acid soap tion of a program involving a new industry of great magnitude. is used m the emulsifying agent during copolymerization. March 28, 1941, Rubber Reserve requested four large rubber Other chemicals are added during the copolymerization step to companies to submit p r o p d s for the construction of four synprovide modification of the molecular structure of the copolymers thetic rubber plants, each with a capacity of 2500 long tons and to control the extent of the conversion. Practically all GRFS annually. In May 1941 the plans were revised to 10,OOO long plants operate on similar flow sheets. G R S Black 1indndes an tons per plant. Immediately following the attack on Pearl additional step whereby carbon black slurries are coagulated Harbor the program wm increased to 400,000 long tons per y m , simultaneously with a given latex stream to produq a rubber and after the fdof Singapore (February 15, 1942) the program containing approximately a third carbon black in the finished was increased in successive stages to a total of 805,000 long tons 569
T .
i
product. G R S is shipped in 75-pound papper-mcked bales in most instances. G R I (Butyl) is produced by the copolymerigation of small mounts of isoprene with isobutylene in the presence of a catalyst at temnerstures below -150° F. and recovered from the solvent menstruum as a snow-white crumb. Extremely large quantities of hydrocarbons and solvents must be recycled in the process. The finished product is shipped in 50- and 75-pound cartons. G R M (neoprene) is produced by the emulsion polymerization of chloroprene, which is manufactured from acetylene and hydrcgen chloride. Numerous ranges of viscosities of the finiahed polymer are available. Shipments are made in hags of 50pound weight in the form of either rope or sheet. Styrene, although produced by several diiTerLnt processes, presents in general a rather simple and straightforward plant flow sheet (2): Ethylbenzene, the basic intermediate; is produced from both alcohol and petroleum sources by alkylation of ethylene directly with bemene in the presence of a catalyst. Since commercial production of styrene was substantial prior to the war, the problems inherent in this operation were welt understood. Butadiene is produced from alcohol and petroleum. The operatiom of the alcobol-type plants as they were constructed were almost antirely similar; however, the petroleum-type butadidne process utilized three basic materials, including naphtha, butanes ( I ) , and normal butylenes (9). The prooasa for the
recovery of products varied in that widely different types of 8 vent recovery systems were employed. Differences in solve1 used created dissimilar process- and wastehandling problems. Table I lists the plants of the government rubber progrr according to location rather than type and presents the wal sheds involved in their operations. I n certain locations the 001 hined wastes of the operations present a CIWsection of all t typical operations necessary for production of a given type chemical rubber. Thus, at Louisville, Icy., where the 01 Riluer receives the outfall from the plants, an alcohol hntadie unit, a carbide plant including facilities to produce acetylene a nitrogen, two G G S copolymer units, and a neoprene plant are operation. At Los Angeles, Calif., two copolymer plants, a I troleum butadiene plant, anda styrene unit u t i h ? theDommgu Channel as their outfall for industrial wastes. BY-PRODUCT WASTES FROM SYNTHETIC RURBER
A wide variety of organic chemicals are employed in the pl duction of intermediate and finalproducts of the synthetic rubt industry. The chemical characteristics of these compounds 8 welt known when referred to the reactions that are essential producing the quality of materiak needed for production of E perior grdes of synthetic rubber. This knowledge, howew does not extend to the behavior of many of these compounde water environment and their effect upon stream eanitntic
May 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY
Generally, hydrocarbons essentlal to thebe processes a1e only slightly soluble in water, so that measurements are best expressed in teims of parts per million. hlany of these materials can he ondized by bacterial activity in receiving waters and thus create a n oyygen demand that may result in depletion of the dissolved oxygen content of the waters. Earlier in the program ethyl alcohol Tas a n important raw material uwd in the production of butadiene, but today the greater part of butadiene used in the industry is derived from petroleum products. Butyl rubber and neoprene are important components of synthetic rubber production but are produced in relatively m a l l quantities compared t o GR-S. Table I1 lists raTv materials used in producing GR-Sand in preparing its two principal constituents, butadiene and styrene. Table I11 presents recent analytical data on typical GR-Splant liquid wastes. ¢ average analytical data on typical butadiene (petroleum) plant liquid n-astes are shown in Table IS' and on styrene plant liquid naqtea in Table S-. PROGR4\I FOR SOLUTIO\ OF W 4STE PROBLETI
Since so many problems arose from the large scale operation of these new units of hmeiican industry (Table 11,it was impoqsible
l n h l e I. I-. 6 . Rubber C o .
Akron, Ohio
Firestone Tire & Rubber Co.
to analyze each problem n-ithin a reasonable time and provide adequate facilities for the handling, recovery, treatment, and disposal of liquids, solids, and gases. Furthermore, in common n-ith many war-built facilities, the plants of the rubber program m r e constructed with the least possible expenditure in time, labor, and money. Because of the lack of experience with most of the proc-, esses of synthetic rubber manufacture, many of the treatment and disposal problems mere unique and required the attention of specialized personnel I n some cases it TTBS necessary to undertake experimental programs of some magnitude. Many improvements had been carried out in 1913 and 1944 in localitiwwhere conditions of stream and atmospheric sanitation Tvere critical. During 1945 and 1916 the remaining problems connected xvith waste disposal were surreyed in detail, improvement programs initiated, and many individual projects installed. Early in 1945 the follo~ving policy program was promulgated by Rubber Rwcrve: Liquid and gaseous discharges from all plant ishould he reasonably free from objectionable materials which might cause trouble when these matcrinls are discharged into water courses or atmosphere. Facilities for the adequate handling, recovery, treatment, and
Plants of the Go\ernment Rubber Program Taps
S a u g a t u c k , Conn
01'
PLAXT Gll-S
R A T E DC.~PACITY PER
Modifier GR-S
Goodrear Synthetic Rubher Corp
GR-S
30,000 I..T.
Vniversity of Akron
Laboratory
Ash r a b uI a , O hi o Toledo, Ohio Iiobuta, Pa.
Sational Carbide Corp. Sun Oil Co. Koppers C0.d
Injti'ute. TT-. Y a .
1.. S . Rubber Co. Carbide Carbon Chem. Corp 1
Calcium carbide Butadiene Butadiene Styrene GR-S Buradiene Styrene
4
T a t l . Synthetic Rubber Corp. Carbide 6; Carbon Chem. Corp Sational Carbide C o r p , Q
GR-S GR-S
Butadiene Acetylene Sitrogen
nu hlempliii, Tenn. Batoii I l o u g e ,
Q
P o n r Co. 0 . Cheiii. C ' o . '
L3, Copolymer Corp.
GR-11 Furfural
Los Angelee, Calif
Ohio R i r e r
Municipal sellerage 6; Kolf River Monte Sano Bayou Monte S a n o Iiavou
JIississippi River
GR-9
30,000 L . T .
Scott Bay
GR-S
Butadiene
Borger. T e s .
Ohio River
Paddy? R u n 6- Ohio River
Butyl
Butadiene GR-S Butadiene GR-S
Scott Bay
Butadiene
40,000 S.T.
Scott Bay
IIoncanto Clieiii. c'o. now Clieii.. Co 1 Goodyear Synthetic Rubber C'orp
Styrene Styrene
GR-S
50,000 S.T. 50,000 S.T. 60,000 L . T .
GalT-eston Bay Rrazos River Siinms Bayou
Sinclair Rubber Inc.
Buradiene
50,000 S . T .
Sirnuis Bayou
B.F Gnodrich Chenl. Co
GR-S Phillips Perroleuni Co. Buradiene Goodyear Synthetic Rubber Gorp.?: GR-S
45,000 I. T. 80,000 S.T.
L)1:c11
60,000 I. T .
11
L-. S . Rubber C
Vol. 39, No. 5
aasist in the flotation process. Suitable provisions are made within the vacuator for skimming floating inat,erial into barometric legs through Tyhich the recovered solids are removed from the unit. Recovered rubber goes t o plant scrap or is destroyed, depending upon its quality. The clarified water is discharged t,o the s e r e r leading t o the final separator. Gravity separators of the t,ypes described are ineffective in removing dissolved materials; in some instances waste waters having a relatively high hydrocarbon content are collectcd after rcgional t,rcatment and subjected to partial distillation as described, to reduce the dissolved content of mat,erials that will affect stream quality adversely. Bnother expedient is aeration of waste solutions, which effects substantial reduction of odors and biochemical oxygen demand. Partial distillation and aeration tire more effective in removing odors than in reducing B.O.D. Process wastes, aft'er regional t,reatment, are generally comIjined in a single conduit leading t,o a final separator. These separators provide means for final removal of separable materials that have not been removed by regional facilities. These units usually are modified American Petroleum Institute gravity scparators, and are frequently provided with facilities for aeration and hay filters for removal of oils that have not been retained in the separator proper. Hay filters are effective for preventing oils or other suspended solids from entering t'he receiving body of water. Final treatment facilities are provided, when necessary, with means for adjusting pH values and breaking oil emulsions. Relatively unstable oil emulsions may be overconie by lengthy storage or by treatment with acids. A method sometimes employed for this purpose is to pass the emulsified solution through 11 sand coalesrer; this permits intimate contact, bet'ween the cmulsion and individual particles of sand. Separation is eff r.ctcd and t.he freed oil is removed in a subsequent gravit'y separator. Inrcst,igation of improved methods of dealing with einul~iorisis in progress.
'I'able I \
.
llutadieiie Plant
KfHurnt, Haied on 50,000
Short Tons per I ear, Furfiiml KecoTery *!*tern Sitnipling Point
IiiihoB rank Storm sewers Lagoon, water clari~icationsludge Final separator Combined storm and process sewer Total effluents
Dissolced . Biochenlic&AT.. Flow, Oxygen, Oxygen Demanda Population Gal./Min, P.P.11, p.p.111. Ib./dny Equiritlentb 13 0 93 14. 5 87 85 ,.. .... .. 104 1463
4.8 1.6
44
775.0
3 5
21 4650
600 2267
...
...
71
510.0 1303.0
3060 7818
:i
..
203 (:. Based on 0.167 uouiid of B.O.D. per capita per day .!-day.
'1
h
I'ahle V. Styrene Plant Effluent, Based on a Kate of'20,000 Short Tons per Year
$nmpling Poinr 1. lienzene sump
2 . Ethylbenzene sump 9 . Styrene jets 1. I'ropane cracking
sump
5 . Styrene cracking
Flow, Gal./Day pH p O a 1,410 8 . 3 3 7 + 1,330
6.52
00,400
5.31 9 +
88,000 187,400 6 : 7 5 187,400 7 . 0 2 966,640 i!6,400,000 6 : k S
sump Aerator fqed (4+.5) Aerator discharge 8 . Sum (1+2+:+7) 9. Main outfall 10 River water entering plant 26,400,000 6 00
2.
,,
6 i
776,500 5 . 8 2 6 +
8y
Population Odorb U.O.D.c, EquivaConcn. P.P.11. lenrd 335 24 192 5 86 80 96 61 2370 768
340
184
3ka'
48
23.2
4;
24
13.5
33bO 217 2616 9900/
3+
12
6.0
..
5+
..,
...
With odor-free distilled water. b Approximate equivalenc of PO value. L d a y biochemical oxygen demand at 20' C . d Based on 0.167 pound B.O.D. per capita per day. e Includes cooling water where once-through system is used. I After adjustment for B.O.D. of river water. 2
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