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Патент USA US2107264

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Patented Feb. 1, 1938
‘ ~ ~ * >
.. 2,107,264?
UNITED STATES
PATENT OFFICE
2,107,264
PROCESS FOR THE PRODUCTKON OF CAR
BON DISULPHIDE
John Philip Baxter, Widnes, and Leslie James
Burrage, Liverpool, England, assignors to Im
perial Chemical Industries Limited, a corpo
ration of Great Britain
No Drawing. Application February 10, 1937, Se
rial No. 125,156. In Great Britain January 3,
1936
9 Claims.
This invention relates to an improved process
for the manufacture of carbon disulphide.
The usual process for the manufacture of car
bon disulphide involves the reaction between ele
mental sulphur and carbon. On a commercial
scale this reaction is generally effected at tem
peratures in the neighborhood of 900° to 1000°
C., the sulphur in the form of vapor being passed
through a bed of the glowing carbon. Many pro
10 posals have been made as to the type of carbon
which may be used. For instance, it has been
suggested that brown coal, anthracite and coke
can be used in the process.
Wood charcoal of
selected qualities is the only form of carbon
15 which has been employed to any extent in com
mercial practice.
This invention has for an object the prepara
tion of carbon bisulphide. A further object is
the preparation of carbon bisulphide from a
20 cheap and readily available source of carbon. _ A
still further object is the preparation of carbon
bisulphide of a good quality in commercial quan
tities. A still further object is a general advance
of the art. Other objects will appear herein
25 after.
These objects are accomplished by the follow
ing invention wherein sulphur in vapor form is
passed through a bed of glowing carbon which
has been prepared by carbonizing coal at a tem
30 perature between about 500° C. andabout 600°
C. The carbon" material may be reacted with
sulphur immediately after the carbonization
treatment or any time after. In the preferred
embodiment of the invention the carbonized coal
35 is subjected to a‘heat treatment at an elevated
temperature in the substantial absence of air for
a few hours and subsequently reacted with sul
phur vapors.
The present invention is based on the observa
40 tion that by the carbonization of coal at tem
peratures of the order of 500° to 600° C., a form
of carbon is obtained suitable for reaction with
sulphur vapor in the manufacture of carbon di
sulphide. This is surprising in view of the lack
45 of success in the working of the prior proposals
on a commercial scale.
At the same time, care
must be taken in the selection of the coal for
carbonization. The various properties which are
to be taken into consideration in this connection
50 include ash content, carbon content, and leaking
properties.
In connection with the ash content it is pref
erable, though not absolutely essential, that the
material be of low ash content in order that
55 possible mechanical di?‘lculties may be avoided
(C1. 23-206)
in carrying out the reaction. Therefore, it is
preferred that the coal before carbonization
should be of low ash content. The carbon con
tent of the initial coal is not critical but prefer
ably it should be of low rank. That is to say,
the carbon content should be relatively low in
the neighborhood of 80% to 82% calculated on
the dry ashless basis.
At the same time com
paratively good results may be obtained when
using material from the carbonization of coal of '10
somewhat higher and somewhat lower carbon
content. On the other hand, it is essential that
the coal submitted to the carbonization process
must not be readily fusible, it must be non-cak
ing and probably should contain a high propor
tion of vitrain.
The conditions under which the carbonization
is conducted must be carefully controlled, in
order that the material produced may be suit
able for successful large scale operation. This 20
latter point is strikingly illustrated by trials
which have been carried out on batches of washed
coals. Average lots of a number of coals of the
type above speci?ed were carbonized at tem
peratures of 400°, 500°, 600° and 700° C., for
periods of 1, 1.5, 3 and 5 hours in each case. Each
lot of coke obtained from these carbonization
runs was examined separately, when it was ob
served that only the cokes produced at tempera
tures of 500° and 600° C. were suitable for car- ‘
bon disulphide manufacture commercially. Even
with these materials there were differences which
were apparently dependent on the duration of
carbonization. Thus the cokes resulting from
the treatments carried out for 1, 1.5. and 3 hours
reacted at rates which were substantially the
same as those observed with wood charcoal nor~
mally used, whereas carbonization for a period
of 5 hours gave a material distinctly less reac
tive.
With regard to the other temperatures we 40
found that the use of 400° C. was ine?ective for
the production of a suitable coke, while the ma
terial formed at a temperature of ‘700° C. was
distinctly less reactive than those produced at a
temperature between about 500° C. and. about 45
600° C. This temperature range appears to be
quite critical for the production of a suitable form
of coal carbon for the reaction with sulphur, as
We have found that a variation of much above
20° C. on either side furnishes a product which 50
is markedly inferior.
Carbon produced .in the manner described
above is, when examined visually, characteris
tically different from coal carbon produced by
normal coking processes and which is unsuitable
2,107,264
2.
for carbon disulphide manufacture. Whereas an
unreactive coke has a silvery-grey appearance,
the material used according to the present inven
tion is quite black. Although not conclusive, this
property enables a preliminary estimate to be
made of the suitability’ of coal carbon for the
reaction. Another property by which the car
bon may be evaluated for the sulphur reaction
is the rate at which it reacts with oxygen. Suit
able carbons burn rapidly when heated in a flame
limited to the specific embodiments thereof ex
cept as defined in the appended claims.
We claim:
1. The process for the production of carbon
disulphide by reacting carbon and sulphur in’
known manner, characterized by the fact that
the carbon used has been obtained by carbon?
izing coal between the temperatures of approxi
mately 500° C. and approximately 600° C., for a
10
period of 1 to 3 hours.
2. The process according to claim 1 further
in air as compared with a slow burning rate of .
characterized by the fact that the carbon sub
unreactive carbons.
sequent to the carbonization and prior to the re
The reaction between the carbon and the sul
phur for the production of carbon disulphide is action with sulphur has been submitted to a heat
treatment'in the neighborhood of 700° C.
15 carried out in the normal manner, for example,
by charging the carbon into a vertical retort and
passing‘sulphur'vapor through the glowing mass
while maintaining a temperature of about 900°
to 1000° C.
20
'
It is» possible to use directly in this reaction
the carbon produced by the carbonization of
coal at 500° to 600° C. without any intermediate
treatment. We ?nd, however, that such carbon
contains an appreciable content of combined
hydrogen, a large proportion of which reacts with
sulphur to form hydrogen sulphide during the
manufacture of the carbon disulphide. This ob
viously reduces the efficiency of the process and
in any case increases the equipment necessary
for the treatment of the effluent gas from the
process. Accordingly, we ?nd it desirable to
submit the coal carbon to a heat treatment
shortly before it is passed into the carbon di
sulphide retort. This heat treatment may be
carried out in the substantial absence of air in
any convenient form of apparatus and con;
sists merely in heating the carbon to about 600°
C. to about 800° C., and maintaining this temper-'
ature for some hours.
In this heat treatment
40 some lowering of the’ reactivity takes place, but
this is more than offset by theresulting gain in
the general e?iciency of the carbon disulphide
production. At the same time, however, it is
necessary to avoid the use of temperatures ma
45 terially higher than the above. If too high tem
peratures are used, the rate of the reaction be
tween the sulphur and the carbon becomes too
low for e?icient commercial production.
From a study of the above speci?cation, the
50 advantages of the above invention will be read
ily apparent. The chief advantage of the in
vention lies in the fact that an initial raw ma
terial which is inexpensive compared with wood
charcoal becomesrreadily available for the pro
55 duction of carbon disulphide. Other advantages
reside in the fact that carbon disulphide may be
easily prepared in commercial quantities and in
high quality.
'
As many apparently widely different embodi
60 ments of this invention may be .made without
departing from the spirit and scope thereof, it is
to be understood that this invention is not to be
3. The process for the manufacture of carbon
disulphide which comprises carbonizing a non
caking coal preferably of low ash content and
relatively low carbon content at a temperature
of approximately 500° to 600° C., for a period 20
of 1 to 3 hours, and reacting the carbon thus
obtained with sulphur.
4. The process according to claim 3 in which
the carbon is submitted to a heat ‘treatment sub
sequent ‘to a carbonization process and prior to 25
the reaction with sulphur.
'
5. The process of preparing carbon disulphide
which comprises passing sulphur vapors over
a bed of carbon material which has been pre
pared by carbonizing ‘coal at a temperature be 30
tween about 500° C.>and about 600° C., for a
periodof 1 to 3 hours.
7
q
6. The process of preparing carbon disulphide
which comprises carbonizing coal at a'tempera
ture between about 500°C. and about'600° C. for‘
a period of 1 to 3 hours, and then passing sul
phur vapors over a bed .of such material main
tained at an elevated temperature.
7. The process of preparing carbon disulphide
which comprises carbonizing coal of low ash 40
content and low carbon content at a temperature
between about 500° C. and about 600° C. for a
periodof 1 to 3 hours, heating the carbonized
product to a temperature of about 600° to 800°
C., and then passing sulphur vapors over theheat
treated product which is maintained at an ele
vated temperature.
.
r
8. The process according to claim 7 wherein
the heat treated product is maintained at a tem~
perature of about 900° to 1000° C.
‘
-
50: >
9. The process of preparing carbon disulphide
which comprises carbonizing coal of low ash
content and having a carbon content of about
80 to 82% calculated on the dry ashless basis at a
temperature between about 500°‘to 600° C. for a 5.5
period of from 1 to .3 hours, heating the carbon
ized product to a temperature of about 600° C.
to 800° C. and then passing sulphur vapors over
the heat treated product which is maintained at
a temperature of about 900° to 1000° C.
JOHN PHILIP BAXTER.
'
.
LESLIE JAMES BURRAGE.
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