ECONOMICS OF CHLORINATION PROCESSES PAUL S. BRALLIER Niegara Smelting Corporation, Niagara Falls. N. Y.
c e d i figures'. It is =cult for one connected with the chlorine industry to get accw to sulliciently oompleta data to evaluate such an &te, but this is believed to be as reawnable a set of Iigureaas can be shown. Perhaps the most siepificant ligure is the 80 per cent credited to "chemicals". This is a broad designation, but it m w a great deal when contrasted with the 21 per cent allotted to the paper industry. Paper and textiles were prsct i d y the only outIets for chlorine in the eady days; but even though the chlorine used in paper and textiles is now many times what it was then, the new chemical applications are absorbing almost two and a half times as much as the other two combined.
HLORINA'ITON pmcesm play an important part in modern induschemistry. It is of intamat, therefore, to inquire into their economic aspects The economic8 and the technology of t h w pmcesses are 80 c l d y related that it has not seemed practical to attempt any sharp separation of the two in this diarmssion. The intention, however, is to place the greater emphasis upon emnomica. Nature of Proceases Chlorination prowases may be arbitrarily divided into two general olasaes--those which result in oxidation and thoee which result in subtitution. Oxidation reactions may be typiIied by the bleaching of taxtiles and wood pulp, sterilisstion of water supplies and sew=, and pmoesses such 88 the preparation of ethylene glycol by first chlorinahg ethylene and then substitnting hydroxyl group for the chlorine atoms in the resultant ethylene dichloride. In t h w OM chlorine takes part in the reaction but dwa not appear in the final product. Another alasa of oxidation reactions is found in the chlorination of met&, but mch applications on an industrial scale
Development of Chlorine Industry
PBODUCPION OF C ~ O R I N E . The economic8 of chlorine prowases are obviously based on the economics of the chlorine
are relatively small. Subtitution reactions are typi6ed by the chlorination of carbon disulfide to form carbon tetrachloride, the chlorination of pentane to form cbloropentane, or the action of calcium hypoohlorite on etbanol or acetone to form chloroform. In t h w casea chlorine takes the place of some element in the molecule attacked and remains as a component of the finished product. It is scarcely necessary to point out that chlorinstion procesees are not necessarily the reault of the direct action of chlorine itself but may be brought about by various chlorine compound8 which act 88 cbloridiziing agents.
Chlorination Prooesses and Productn in Industry A great number and variety of indn6tries are atiected by and, to some extent, dependent upon chlorination pmc8e8ea or chlorination products. Table I lists various industries and a few outstandingexamples of the way in which chlorinetion prooesses contribute to them other industries and examplesmight be cited, but those set forth here will aufEce to demonstrate the widespread application of chlorine and ita DrodUCta.
An &te of the proportion of total chlorine which went to various industries during 1939 is &own by the pre152
CHIBRINAT~~N
Fmbmary, 1941
. ?
industry it&. A fair iden of what has been happening during the past twenty years is shown in Table II and Figm 1. Them data attempt to set forth the annual chlorine production and estimated w e d cell capacity. Comparison of the C h m a Bureau's chlorine prcduction figures (column 2, Table 11) with corresponding6gureafor eleotrolytic caustic show a comiderable discrepancy up to 1931. Just how this came about is di5cdt to say, but it on waa probably due either to incomplete retchlorine production, as compared to electrolytic caustic prcduction, or to rules or policies followed by the Census Bureau as to what chlorine production was to be included in the tabulation. A second set of chlorine production 6gurea was therefore derived from the reported production of electrolytic caustic and is presented in column 3. Figure 1 is b d on column 3 rather than on column 2. The fact that the estimated figures for chlorine production fall below those published in 1936, 1937, and 1939 may poasiblyindicate the involume of chlorine produced by the electrolysis of potsssium chloride and also the effect of chlorine produced by the reaction of nitric acid with d t . Chlorine liquefied (column 4, Table 11) was taken from Bureau of Census data where it was listed as chlorine sold. The figures for the number of establishme& prcducing chlorine and liquefying chlorine are open to question for the years 1921 to 1927, inclusive, because it is dehitdy known that not all produoera of marketable chlorine during that period were liquefying chlorine. The last column shows the eatimated inatatled cell capacity for producing chlorine. Them figures do not compare clirectly with the production 6gum in columnn 2 and 3 beoausa the produc-
193
TABLEI. INDWTBIAL APPLICATIONSOF CHL~FXNATION Pmcesses OB h O D U C r S
Automobile Chemical
Ebtrid
Apphaation PDichlorobmene. ethylene diohloride. chloropicrin M fumipants; bssio copper ohloride an fungicide; chlorine and bywobloriten UI atarili*ng agenta in dsiry induetry Ethylene Jycal antif-; vinyl &; ohlorinsted oompounds to improve e5dency of lubricants Bromine fmm ana water; paenol and &e fmm b e m e vis GErCL; -1 oompoun& via oblommtanea; A a l M catslyat in mmmemial appliwtion. of Friedelcrafts reaction Chlomnsphth.Lensa for wire mating and wndenear impregnstion; Chl0rinst.d ammstic hydrooarborn 88 liquid diebtrics CCL M basio vsporising-liquid ertinguiabing agent Vinyl reains for Laminsted safety slssa Beneficistion of ood and o w by aink-and-float aystam; extraction of vdusble oonstihlents of o m by ohlorination, M in produotion of metallic berJlllium Chlorinatedrubber 88 ingredient of mncidty matinla
Refrimration Rubber
Baoitation
T-We
Wood
n
n
Chlorine and bypoohlorite. in refining and blesahing of fiber Pdpa Dewaxing and remning of Lubrioating oib with chlorinated aoivenm -very and utilimtion of by-pmduota of oil maakinx pmoessea via chlorination and hydrolysis; HCI for inoutput of oil wnlle: AlCIi M oatelvat in on mschng CHGI. c+HsCL. and CClrF.as refrigerants Sulfur chloride for oold vul-ution of rubber; HCI in mmufaotum of neoprene; ohlorinstion of rubber; diohl0rc-n-butane in manufact- of butadiene; ethylene dichloride in manufact- of Thiokol , Chlorine and bleaching powder for stenluation.m d f e m v ohloride for flweuktion in p u r i f i ~ ~ t of i ~ ~potable , w a k ; ohlorins for steriketion of ew-; chlorine for control of obnoliow odors BleMhing with NsOCI, CaOCI*, Ce4OCl)r. ohloritas; dry Cleenbg with CCh. GHclr. c1ck wool treated by carbonisation with AlCb, or renderad Unshrinhhle with BOrClr or tmtiaw -1 or butyl hypoohloritem; vinyl chloride polymer M a w t h e t i c fiber Saccherifio&m of nood with HCL
ing capacity estimate includes chlorine capacity instslled in paper rbdk for itheir own use, wheress the production
figures are limited t o chlorine made to be sold as liquid chlorine or as chlorine productat. In 1939 the W e d capacity in paper milla was estimated at 86,300 tons.
Pmm OF C m o m IWD ITS h a p a r , PRODUC~S. Another indication of economic trends in the industry is to be found in a comparison of prices for liquid chlorine, bleaching powder, carbon tetrachloride, and caustic soda over the corresponding period (Table I11 and Figure 2). The figures Shown repwent prices hoped for rather than attained, since TABLE11. ANNUAL C h m m DUCTI ION am INSTALLED CELLC A P A C ~
-Amran 1. ANNUAL Cmamm P~DUCITON
INDUSTRIAL A N D ENGINEERING CHEMISTRY
rs4
they were tgken from published market quotations. It is believed, however, that they do have a fairly definite A t i o n to prices actually in &ect on the data indicated. a
Tasw 111. Prum DATAm n HUNDEEOWXIO~ & of
Nor.16
Liauid ChldxW
ElPowder
cubon Tstnohloridsl
C.&
Sod*
GsoaRnwicar.Tasnms. Still another signiIicanteconomic indicator ia the geographical trend in the incresae of chlorine producing capacity. New uem for chlorine have taken it into new locstions. Even m e of the older chlorineconsuming industries, such M the paper industry, have been expanding into new territory, and chlorine production has shown a corresponding tendency toward decentnlisation. Cheap salt and cheap power have always been important considerstions in the chace of location for a producing unit; but high transportation costa from the older estabbhd catera have permitted chlorine insoallatiqne in territories where salt and power oosta are relatively high. As late no 1929 nearly 60 per cent of the total chlorine p m duction of the United States wan in New York State. New York tonnage in still a sixable percentwje of the whole, hut recent trends have been toward diminishing ita share. Table N bta new chlorine cell imtallationa by alkali manufacturera since 1928, during which period practically all of the Bxpansion has *en p h . Not dl of the inomwed capacity ia to he credited to these new jnatallationa since the older producers have Likewise increased the capacity of their original units. The trend away from the older eatahlished centern in New York, Michigan, and We& Viiginia in Unmiatakable.
New Applicatiolu for Chlorine. Chlorine Roducta, and Chlorination Proceuu, Possibly the eimpleat way to show the internation of economies and ~ o l o g in y chlorination promaw ia to review brietly wme of the outahding developments, particularly within the lsst twenty years, keeping in mind the development of the chlorine industry iteelt, which dates from approximately 1789. An attempt to do this ha$ been made in Table V. As in Table I, no claim is made for completenesa of coverage, but Table V does contain numerous examples of the interplay of eoonomic fsdors in thie 8peCi6C field. Several dmces have bepm included to utiliration of hydrogen and to developmanta in the art of evaporating and purifying caustic &a. Them are not chlorination pmoesees, but the inauence of obtaining m e revenue from the typroduct hydrogem in the one case, and of hding more ready marketa for what may be termed “by-pmduct w t i c eoda” in the other, on the manufactum of chlorine i W is 110 obvious ae to require no detailed explanation. Future of Chlorination Proeesae
Beoause of their vmtility, chlorination pmoessee will always be gim ear& d d e r a t i o n in any development, particularly in the field of organio chemistry w h the mast spectaaular advances are being made. A t the eame time, chlorination promma bave their own psmrliarities and in-
V d 33, No. 2
herent di5cnlties, and there will continually be strong competition betwesn the chlorination method of attaining a d e sired reault and other methoda of oxidation. At least two clear-cut exemplea of thia tendency are eited in Table V. One wae the u88 of sulfur chloride in the production of acetic anhydride, which began to mume interatiag proportions a b u t 1928and accounted for a suImt8ntie.l tonnagaof chlorine during the first ~ e v e nyears of the 1930’8,only to be sup planted in 1938 by a etrsight oxidation p.The mend is the increasing competition which is being given to hypochlorite bleaching pmceases by hydmgm peroxide and milium peroxide. There are undoubtdy other inStgncas of the 881118 mrt, but these two indicate the tread.
1818
1819 1880 1836
1837
Dismond Alkali Co. EookerELsatmohemiod&. Pennsylrsnia8alt Mfg. Co. Columbia Alkali Corn. BolVW P r o w Co.
E&Po& Chemicd proms,.
1839
PbinedViUe. Ohio Tam- W u h . T m m a Wuh. Barberton. Ohio
Co.
In the last analysis, that pnmess will be adopted which yielda the deaired product at the lowest cost. Low-price chlorine, adequate in volume to meet all p m t demand, should give ohlorination prom%% their best chance to &and up against the pressure of competitive processes. The rapidly expanding volume of chlorine production coupled with modem chemical engineering developments has made for a reduction in the cost of producing chlorine, which bae been passed on to the cblorine oonsumer. ChIorine prim today am the lowest in the history of the industry. At the same time the capacity for the production of chlorine has never been greater. These conditions should be the most dective h a n c e for the oontinued gmwth of the chlorine industry and for the continueduse of chlorination in the preparation of producta now in u88 ae well ae the new products that will he developed by the resesrch of today and tomorrow.
F.bauarp; 1941
CHLORINAT~ON
Cubon tatrMhloride lira produced in U. 8. Blenohh# PO& 6mt applied to purifiastion of drinldno n t e r in U. 8. at Chics~o First mmmeraid abioment. of liouid ablaine in U. 8. made for uam in taxtile hhohina
19% lDaa
19.27
19%
1-
lSa0 1881
1981
1988
19a4 1986 1988 1887
155
