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Патент USA US2110174

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Patented Mar. 8, 1938v
2,110,174
UNITED STATES PATENT OFFICE
2,110,114
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METHOD OF MAKING cannon ram'
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CHLORIDE
John 11. mm’, Midland, Mich, assignor to The
Dow Chemical Company, Midland, Mich, a cor
poration ofli?chigan.
Application December 2, 1935; Serial No. 52,462
13 Claims. (01. zen-10s)
It is well known that carbon tetrachloride is
formed by reaction of carbon bisulphide and sul
phur chlorides, either the monochloride or di
I have found that by carrying out the reaction
of carbon bisulphide with an excess over the stoi
chiometrical proportion of sulphur chloride
chloride, in the presence of a catalyst such as iron
5 chloride or antimony chloride, in accordance with
under a pressure of about 11/2 atmospheres or
more the carbon bisulphide can be completely
the theoretical equations:
reacted so that the necessity of separating resid
ual carbon bisulphide from the carbon tetrachlo
ride product is eliminated. I have found further
that a reversal of the reaction is prevented by
distilling the carbon tetrachloride irom the reac1 m It is also known that the reaction does not go tion product under a similar pressure. The im
to completion, however, and is in fact a reversible proved method can be carried out in various ways.
reaction which reaches a state of equilibrium, For example, the principal reaction can be con
varying with conditions, so that the end product ducted under a pressure of 11/2 atmospheres or
u always contains more or less carbon bisulphide more and the carbon tetrachloride product disand sulphur chloride.
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tilled from the mixture without release of pres
Up to the present time in all commercial proc- ’ sure. In another modi?cation the principal re
esses of which I am aware, the process has been action may be carried out at about normal pres
carried out as a batch operation, yielding a car-o ' sure, and the product thereof then heated under
bon tetrachloride ‘product which is accompanied higher pressure to complete the reaction, the car-
20by considerable amounts of carbon bisulphide *bonytetrachloride being distilled from the mix
and sulphur mono-chloride, $2012.
5
10
15
20
The puri?ca-' ' ture under pressure, either coincidentally with
tion of such product is a tedious and diiilcult op
eration, owing especially to the fact that carbon
25 bisulphide can be separated from carbon tetra
, chloride by distillation in the presence of sulphur
such further heating, or subsequently thereto.
In a preferred embodiment of the invention a
' mixture of carbon bisulphide and an excess over 25
the theoretical proportion, of sulphur chloride,
and sulphur monochloride only with extreme .most advantageously the dichloride, is pumped
di?iculty,‘ several distillations being necessary to under moderate pressure, i. e. 1.5 to 10 atmos
obtain a commercial'grade of carbon tetrachlo-l - phere's, through a tubular reaction coil of suit
ride. Various chemical methods have been pro
able length, for which an iron or steel pipe is best 30
30 posed for removing the last traces of carbon bi
' adapted, since the iron supplies the catalyst for
sulphide, so as to yield a carbon tetrachloride of the reaction. The mixture at ?rst may be
high purity. The numerous steps heretofore re
slightly warmed to initiate the reaction, which
quired for the puri?cation of the crude reaction
35 product have contributed materially to the cost
of manfacture.
.
It is among the objects of the ~present inven
then proceeds exothermically with evolution of
considerable heat. Such heat is controlled by 35
suitable cooling, so that the average temperature
of the ‘reaction mixture is maintained between
tion to avoid conditions permitting a reversal of , about 40° and about 150° C. The reaction prod
the principal reaction, and to produce a higher
uct, while still under pressure, is discharged into‘
'40 yield of carbon-tetrachloride. A particular'ob-_v ‘a still, and distilled under pressure to separate 40
ject is to obtain a reaction product substantially _ carbon tetrachloride from the residual sulphur
free- from carbon bisulphide, ‘thus avoiding the
di?iculties of D
and sulphur chloride. In this way the carbon
ying the product thathave. bisulphide ‘may be completely reacted, so that
existed in pre’ us processes. Another object is‘ > ‘the separated‘ carbon tetrachloride is substanto provide a continuous method of operation. "-tially tree from any traces thereof. It can then 45
Other objects and advantages will appear as the be ?nally puri?ed by redistillation over lime or
description proceeds. _ The invention, then, con-v _' other alkali, in the usual manner.
I
sists in the improved procedure hereinafter fully
steps which I perform in carrying out my
described in the annexed drawing and accom'-' improved method for making carbon terachloride.
5o panying speci?cation, and particularly pointed can best be described by reference to the annexed 50
out in the claims. ‘ . -'
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drawing. In the single ?gure, the raw materials
In said annexed drawing, the single ?gure is a. for the process, 1. e. carbon bisulphide and sul
diagrammatic representation of a combination of j phur dichloride, are drawn from suitable sources
apparatus adapted for carrying out the inven
through pipes l and 2, respectively, to a'pump
3, which forces the reaction mixture through a 55
55
tion.
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2,110,174
pipe 4 into the coil reactor 5, preferably of iron
suits obtained by the present invention, but is not
or steel, under a pressure varying between 1%
and 10 atmospheres. An excess of sulphur di
to be construed as limiting the same.
chloride over the theoretical proportions as shown
1
in' Equation (2) is normally fed into the reactor
Over a period of three hours 4543 grams of car
coil, preferably in quantity corresponding to
bon disulphide and 18,460 grams of sulphur di
about a 50 per cent excess thereof, to cause reac
chloride were introduced under pressure, ata sub
stantially uniform rate, into a reactor consisting
of a coil of 0.54 inch i. (1. extra heavy iron pipe 30
feet long placed in a water bath. The flow of 10
cooling water around the reactor coil was main
tion to proceed approximately according to the
following equation:
10
The reactor coil 5 is disposed in a tank 6, through
which a temperature regulating liquid such as oil
or water, is circulated via an inlet 1 and an out
15
Example
let 8, the temperature and rate of flow of the liq
tained at a rate such as to give reaction tempera
tures from 50° C. at the start of the run to 70° C.
at the finish, while the pressure within the reactor
ranged from 1% to 2% atmospheres. The reac
uid medium'being such as to maintain the tem
tion products passed continuously from thereac
perature of the reaction mixture in the coil 5 be
tor to a continuous column still maintained under
tween about 40° C. and about 150° C. The reac pressure, and carbon tetrachloride was distilled
tion product from the coil 5 ?ows through a therefrom. The still residue was continuously
20 pipe 9 to the column ll of a continuous pressure withdrawn and throttled into a second still oper
still II). From this still l0 carbon tetrachloride is ated at atmospheric pressure in which sulphur
vaporized under pressure corresponding to ‘that monochloride was distilled from the free sulphur
in reactor 5, and the vapors pass of! into‘ a con
at a temperature of about 140° C., and the latter
denser ", through which cold water is circulated withdrawn as molten sulphur. There was ob
25 via an inlet 20 and an outlet 22, wherein the car
tained 9115 grams of carbon tetrachloride, or a
bon tetrachloride is condensed and drawn on yield of better than 99 per cent of theoretical.
through a pipe l3 and a throttle valve ll to stor
Analysis showed that the carbon tetrachloride
age. The residue from the pressure still l0, con
contained less than one-tenth of one per cent of
sisting of sulphur monochloride and free sulphur, carbon bisulphide.
30 flows through a throttle valve ii to a column I‘!
By means of our improved method carbon
of a still is operated at atmospheric pressure or tetrachloride of excellent purity is produced in
perferably under vacuum. Sulphur monochlo
two steps involving one distillation, and the dif
ride vapors pass over from the still it into a con
ficult separation of carbon bisulphide from the
denser IB, through which water is circulated via product, which has been a disadvantage of prior
35 an inlet 2| and an outlet 23, wherein the mono
processes, is avoided. The yield is practically
chloride condenses and may be drawn 01!. The theoretical and a considerable reduction in the
sulphur monochloride recovered may be reacted number of operating steps and in the apparatus
with chlorine to give sulphur dichloride, which required is obtained, compared with‘ present com
is then returned to the ?rst reactor. The free mercial' practice.
40 sulphur, in a molten condition, is tapped of! from
Other modes of applying the principle of my
the bottom of the still l8 through a pipe l9.
invention may be employed instead of those ex
Although, as above stated, an‘ approximately plained, change being made, as regards the method
50 per cent excess of sulphur dichloride is pre
herein disclosed, provided the steps stated by any
ferred for carrying out the process, either a of the following claims or the equivalent of such
45 larger or smaller excess thereof may be used, if stated steps be employed.
desired. The larger the excess of sulphur di
I therefore particularly point out and distinctly
chloride, up to a ratio of 6 moles thereof to 1 mole claim as my invention:—
of carbon bisulphide, the greater the proportion
l. The method for the production of carbon
of sulphur monochloride to sulphur in the prod
tetrachloride which comprises reacting carbon
50 uct, as shown by the equations:
bisulphide with sulphur chloride under super
20
25
30
40
45
50
atmospheric pressure of at least 11/2 atmospheres.
2. The method for the production of carbon
55
The products of the process are, therefore, carbon
tetrachloride free from carbon bisulphide, sul
phur monochloride, and sulphur, the proportion of
tetrachloride which comprises reacting carbon
bisulphide with sulphur chloride under super
atmospheric pressure of at least 1% atmospheres 65
at a temperature between about 40° and 150° C.
3. In ‘a method for the production of carbon
tetrachloride, the steps which consist in reacting
sulphur monochloride increasing with the excess carbon bisulphide with sulphur chloride under
60 of sulphur dichloride employed, while that of
super-atmospheric pressure of at least 1 1/2 - atmos 60
sulphur decreases. If it is desired to make sul
pheres and distilling carbon tetrachloride from
phur monochloride as an additional product, it the reaction product under’similar pressure.
may be advantageous to increase the excess of sul
4. In a. method for the production of carbon
phur dichloride, over that called for by Equation ' tetrachloride, the step which consists in feeding
65
(2), to as much as 4 moles, i. e. an excess of 200 carbon bisulphide and an excess of sulphur chlo 65
per cent (Equation 6).
ride simultaneously into a reaction chamber
When it is desired to employ sulphur monochlo
maintained under super-atmospheric pressure of
ride as a starting material, in accordance with at least 11/2 atmospheres, while maintaining the
70 Equation (1) , the method is similar to that just mixture at a temperature between 40° and 150° C. 70
described and the reactants are advantageously
5. In a method for the production of carbon
employed in the proportions of about two to three tetrachloride, the step which consists' in feeding
moles of sulphur monochloride to one mole of carbon bisulphide and an excess of sulphurdi-i
carbon bisulphide.
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chloride simultaneously into a; reaction chamber
75 The following example is illustrative of the re
under a pressure between about 1% atmospheres
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mixture at a temperature between 40° and 150° C.
6. In a method for the production of carbon
tetrachloride, the step which consists in reacting
10
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2,110,174
and about 10 atmospheres, while maintaining the
sure and, while maintaining such pressure, dis
tilling carbon tetrachloride therefrom.
10. In a method for the production of carbon
carbon bisulphide with sulphur dichloride at a
temperature between about 40° and about 150° C.,
under a pressure between about 11/2 atmospheres
and about 10 atmospheres.
tetrachloride, the steps which consist in continu
ously forcing a mixture of carbon bisulphide and
7. In a method for the production of carbon
mixture at a temperature between about 40° and
tetrachloride, the step which consists in reacting
carbon bisulphide ‘with sulphur dichloride at a
temperature between about 40° and about 150° C.,
under a pressure between about 11/2 atmospheres
and about 10 atmospheres, and distilling the car
bon tetrachloride so formed from the reaction
product at a similar pressure.
8. In a method for the production of carbon
tetrachloride, the step which consists in reacting
1 molecular equivalent of carbon bisulphide with
about 3 molecular equivalents of sulphur dichlo
ride at a temperature between about 40° and
about 150° C., under a pressure between about 11/2
atmospheres and about 10 atmospheres, and dis
tilling the carbon tetrachloride so formed from
the reaction product at a similar pressure.
9. In a method for the production of carbon
tetrachloride, the steps which consist in continu
ously forcing a mixture of carbon bisulphide and
30 an excess of sulphur chloride through an elon
gated tubular reactor while maintaining the mix
ture under super-atmospheric pressure of at least
11/2 atmospheres and at a temperature between
about 40° and 150° C. and discharging the reac
tion mixture into a still without release of pres
an excess of sulphur dichloride through an elon
gated tubular reactor under a pressure between
11/2 and 10 atmospheres while maintaining the
150° C., and discharging the reaction mixture into 1O
a still without release of pressure and distilling
the same under similar pressure to separate car
bon tetrachloride.
11. In a method for the production of carbon
tetrachloride by reacting sulphur chloride and 15
carbon bisulphide, the step which consists in
fractionally distilling carbon tetrachloride from
the reaction mixture under a super-atmospheric
pressure of at least 1% atmospheres.
12. In a method for the production of carbon 20
tetrachloride, the steps which consist in reacting
carbon bisulphide and an excess of sulphur chlo
ride over the stoichiometrical proportion, such re»
action being completed by applying to the reac
tion mixture a pressure of at least 11/2' atmos
pheres, and distilling carbon tetrachloride there
from under a similar pressure.
13. In a method for the production of carbon
tetrachloride, the steps which consist in reacting
carbon bisulphide and an excess of sulphur 30
chloride over the stoichiometrical proportion, and
distilling the reaction mixture under pressure of
at least 11/2 atmospheres to separate carbon
tetrachloride therefrom.
JOHN H. REILLY,“
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