DISULFIDE

CARBON
DISULFIDE
9
Emphasis in raw materials shfts
further from charcoal to methane,
but impact of new processes using
coke or liquid petroleum fractions
remains to be seen
HARRY W.
HAINES, JR.
variety of reactions are available for making carbon
A disulfide, but only two have become important
commercially; one is from carbon and sulfur and the
other from methane and sulfur. The classic method
uses charcoal and sulfut--heat is applied with carbon
electrodes to a hearth or to retorts directly fired by
natural gas, producer gas, or other fuels. Recently,
however, especially in the United States, production
from methane and sulfur has become more common.
Considerable data on carbon disulfide are available
in the literature, including a description of both routes
of manufacture (6). An excellent thermodynamic
analysis of both the methane and charcoal routes is
given (7) and, for the methane route, thermodynamic
and kinetic data are available (2, 8) as well as kinetic
data for plant design (7,3). Thermodynamic properties
of sulfur ( 7 I), carbon disulfide (5),and hydrogen sulfide
(10) are tabulated in the literature.
REACTIONS FOR MAKING CARBON DISULFIDE ( 4 )
F.
CH, + 4/nS.
=
CS,
+ 2HIS
c + z/ns. = cs,
ZCO + 2/nS. = 2 c o s = cs, + CO,
c + zn,s = csI + ZH,
5C
+ ZSO, = CS, + 4CO
1050-1300
1200-1550
800-850
2025-2075
2250-2300
Methane RoulhProcess Technology
T o obtain satisfactory reaction rates, most plants use
temperatures above 1000° F., although stoichiometric
convenion is theoretically possible at temperatures as
44
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
ow as 6OOOF. Pressures are 20 to 30 p.s.i.g. Saturated
ulfurvaporat 1180°F.contains210/0diatomic,58’%hextomic, and 21y0 octatomic molecules (9). However,
vailable kinetic data are correlated satisfactorily by
ssuming a second order reaction between methane and
diatomic sulfur which Is probably the true reactant.
Activation energies of 61,920 and 68,940 B.t.u. per
pound-mole have been reported. At space velocities of
600 standard cubic feet per cubic foot per hour, catalytic
reactora generate 35 pounds of carbon disulfide per hour
per cubic foot of catalyst. Some plants are designed to
operate on the exothermic and some on the endothermic
side of the adiabatic reaction temperature of about
1200’ F. Heating the reactants (neglecting heat losses)
requires about 1650 to 1750 B.t.u. per pound of carbon
disulfide product.
Carbon disulfide can be made from methane and sulfur by either a high or low pressure purification process
(Figure 1). In either case, the methane should contain
less than 1% propane and heavier hydrocarbons and no
more than 2% ethane. The high pressure process is
especially applicable for small plants where recovery of
hydrogen sulfide is uneconomical and where the hydrogen sulfide may be used elsewhere as a reactant.
Coils in the sulfur vaporizer are of high-chrome steel,
and the reactor also is preferably of this material. Distillation towers in the purification section can be of carbon steel.
ne^ Me~hods
Although the methane route has many advantages
over the charcoal method, incentives to develop new
processes still exist, particularly for foreign areas where
low cost methane is unavailable. An inventor of the
original methane process, Carlisle M. Thacker, is work-
METHANE ROUTES FOR MAKING
3
.
2
ing on a technique for making carbon disulfide from
liquid petroleum fractions, and has patents pending.
His purification system is reported to be nearly the
same as those in conventional plants using kerosine as
lean oil. Sulfur is vaporized, but Thacker has not indicated the degree of superheat added to the petroleum
fraction or reactor operating temperatures. He claims a
lower raw material cost, a higher yield of carbon disulfide, less preheat, and lower purification costs.
Shawinigan Chemical also has a new method based on
its Fluohmic furnace, a resistance-heated fluidized bed.
Sulfur or hydrogen sulfide may be used as the reactant
and in laboratory tests, conversions up to 70% were
produced when gaseous sulfur, or liquid sulfur which vaporizes as it enters the chamber, flowed upward through
a coke bed heated to 2000O to 2200' F. Other laboratory tests showed that about 70% of the hydrogen sulfide
fed to a coke bed was converted to carbon disulfide at
2700' to 2750' F., with apparent efficiencies of 90 to
100%. In some tests efficiencies actually exceeded
loo%, because sulfur in the coke entered the reaction.
Economic Aspects
Total carbon disulfide capacity in the United States is
difficult to estimate (Table I), but the shift from charcoal
to methane is marked. At one time Stauffer Chemical
had seven charcoal plants in operation and DowChemical
operated one at Midland, Mich. Because of this shift
and lower costs, production of carbon disulfide, since
1958, has been increasing about 6 to 7% per year. One
50 million pound-per-year plant is under construction.
However, this production picture may be affected by
an impending merger. Regenerated cellulose consumes
about 80% of the total carbon disulfide output; this is
a big factor in the planned acquisition by FMC Corp. of
American Viscose, a leading rayon manufacturer which
has also one fourth of the nation's cellophane capacity.
FMC may have a better chance than Stauffer Chemical
which was thwarted by the Justice Department last year
from acquiring American Viscose. If FMC is successful,
considerable plant expansion may result.
TABLE 1.
CARBON DISULFIDE PLANTS
Capaity,*
Millim
,J. T. Baker Chemical
Penn Yan, N. Y.
FMC Corp. & Allied Chemical
So. Charleston, W. Va.
Old Hickory Chemical
Old Hickory, Tenn.
Richmond, V O . ~
Pennsalt Chemical
Houston, Tex.
Pittsburgh Plate Glass
Natrium, W. Vo."
So. Charleston, W. Vo.'
Stauffer Chemical
Delaware City, Del.
Lowland, Tenn.
Charcoal
<m
Methane
100
Charcoal
Chorcoal
Coptive
Captive
Methane
<IO
Harry W . Haims, Jr., is a Consulting Chcrnical
Engimn and owner of Haims t
3 Assnciater in Houston, Tex.
-
50
Methane
Methane
10
Methane
Chorcoal
340-360
~
6W6B
Total
AUTHOR
D./Y,.
Rous Mafm
Combanv
LI Estimofed.
* E l e ~ f r o l h i r m n l p ~ ~ ~ Retort
s s , proccss.
d e d for shufdnwn in 7963.
Due on strmn in 1963.
schcd-
(Confinucd on nexf p q c )
CARBON DISULFIDE
:%Wtal-
-
I I\
i
Figtrrc 1. Sulfur vapors p a s fhrough fhe calaly~fchamber of 1200° IO
lwOo F. ond (I rpom velocity of 5W lo 600standard cubic feel pn cubic
fool pn hour. Corbon dim@de is formcdawording to fhc reoclim C H ,
+
I I
l-fl
+
4/nS, = CS, 2 H d . Mosr planfs use 5 f o 70% errersrulfur. Thc
produ6 is couslic-moshcd b t f m goi?i,$ lo sloroge. In 6hc high pressure
proccrr, the mea circled obom ir replactd by 6he reefion in color at I4ft
VOL. 5 5
NO. 6 J U N E 1 9 6 3
45
Although prices have remained firm for many years,
carbon disulfide growth rates have lagged behind those
of carbon tetrachloride (Figure 2). Two main factors
are responsible: demand for the tetrachloride in making
fluorocarbons is strong, and carbon disulfide’s rayon
markets are barely holding their own against major inroads by nylon tire cord.
For carbon tetrachloride, capacity is equally difficult to
estimate, because of the variable output obtainable from
methane chlorination. Trade estimates now are as
high as 570 million pounds per year, but previous figures
were about 400 million. Annual production increases of
6% are predicted for the next five years, even though
carbon tetrachloride seems destined to remain a oneproduct commodity (fluorocarbons). That about 35%
of total output is derived from carbon disulfide is reasonably safe to assume: Diamond Alkali operates a 60million-pound-per-yearplant; FMC Corp., a 50-million;
and Stauffer, now operating a 100-million-pound plant,
plans to put on stream in 1964 a 70-million-pound plant.
Despite the declining tire cord production, however,
rayon output is moving upward (Figure 3). But its
future is difficult to predict. Since Du Pont dropped
CARBON OISULFIDE PRODUCTION
looo/---
~~~~~
1955
1957
1959
I
1961
1963
Figwe 2. Growfh of carbon didJide production lugs behind
of carbon tchachlmidc
that
CARBON DISULFIDES MAJOR OUTLETS
700
v
0
Carbon disu@dc u c poftm
out, only four producers are left: American Enka,
American Viscose, Beaunit Mills, and Industrial Rayon.
This year marks the end of an era for Du Pont, which
entered the rayon business 33 years ago at Buffalo. The
company now has a “radically” new nylon which it
claims reduces “significantly” flat spotting in tires. If
this is so, nylon may be headed for the original automotive equipment market-the last stronghold for rayon
tire cord. Du Pont estimates that nylon cord is now
used for about 70% of the replacement tires on automobiles and trucks, 40% of original equipment truck
tires, and 100% of airplane and off-the-road tires.
Producers of rayon for uses other than tire cords include Celanese, Courtaulds (Ala.), Fair Haven Mills,
Hartford Rayon, and Mohasco Industries.
Meanwhile, cellophane continues to consume more
carbon disulfide. Recent predictions indicate a probable output of 500 million pounds during 1967. At
present, three manufacturers have an estimated capacity
of 540 to 580 million pounds per year: American
Viscose, 150 million; Du Pont, 320 to 350 million; and
Olin Mathieson, 70 to 80 million.
Worldwide, demand for carbon disulfide continues upward but the United States exports very little-less than
1.3 million pounds in 1961. Of this, 672,000 pounds
went to Canada, 445,000 to Colombia, and the balance
was distributed among 12 other countries.
SUGGESTED READING
(1) Fisher, R. A,, Smith, J. M., IND. ENG. C ~ e l r .42, 704-9
O., Miller, E., Hennig, H., Zbid., 42, 2202-7
(November 1950
(3 Fomey, R. C., kmith, J. M., Ibid., 43, 1841-8 (August 1951).
(41 Madon, H. N., Strickland-Constable, R. F., Ibid., 50, 1189-92
(August 1958).
(5) O’Brien, L. J., Alford, W . J., Ibid., 43, 506-10 (Februay
(2)?~k~~,5%.
J
1963
Figwc 3.
o
y
m W
Vkosc rayon ir still fhc !coding ouflel for carbon dmlrfuic
~
A
U
~
Y
~
W., IymldPelrol. 31,62-68 (June 1960).
IND.END.CHEW.41,1968-73 (Scptembcr 1949
M., Miller, E., Zbid., 36, 1 8 2 4 (February 19441:,... :., ., .
(9) Tulla, W. N., “The Sulphur Data Book,” p. 27, McGrawA .J”.
New York, 1954.
>V‘ ,’ .
10 West, J. R., C h . Erg. Pr.gr. 44,287-92 (April 1948).
11 West, J. R., IND.ENG.CHEU.
42,713-8 (April 1950).
I
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INDUSTRIAL AND ENGINEERING C H E M I S T R Y
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