Improvements in the Manufacture of Ammonia, Sodium Hydroxide, and Chlorine, and in Apparatus therefor.
Year: 1893

page_text: Date of Application, 14th July, 1893
Complete Specification Left, 7th Nov., 1893-Accepted, 23rd Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Ammonia, Sodium Hydroxide,
and Chlorine, and in Apparatus therefor.
I, CHARLES KELLNER, of Wasagasse 39 Vienna 1 Austria, Doctor of Philosophy,
General Manager of the Kellner-Partington Paper Pulp Co. Ltd., do hereby
declare the nature of this invention to be as follows:-
This invention has for object to convert nitrate of sodium into ammonia and
hydroxide of sodium. For this purpose an aqueous solution of sodium nitrate pre-
ferably in a heated state is treated with sodium amalgam produced by a continuous
process for the electrolysis of sodium chloride, mercury being employed in such
process to form the cathode.
The chlorine evolved during this electrolytic process may be conducted away and
utilised in any convenient manner. The mercury acts as an important medium by
absorbing and introducing to the nitrate solution the sodium produced by the
electrolytic decomposition of the sodium chloride. The water of the solution is
thus decomposed by the sodium, the hydrogen evolved acting to reduce the nitrate
of sodium to ammonia and sodium hydroxide. The mercury after giving off the
sodium it contained absorbs a further quantity of sodium liberated by electrolysis
from the chloride of sodium in solution and is ready for a repetition of the
process.
The whole of the operation proceeds with perfect regularity. By placing an
electrode in the solution of nitrate the mercury forming the other electrode, a
galvanic cell is formed enabling the heat generated to be converted into electrical
energy and utilized for any suitable purpose such as for example relieving the source
of current employed for decomposing the chloride of sodium.
The main features of novelty in the process are as follow:-
(a) The employment of an anode (say of platinum or carbon) having a much
larger surface than the mercury opposed to it as a cathode.
By this arrangement an inconvenience which has hitherto attended all processes
in which mercury has been used as a horizontal cathode is avoided, none of these
processes having proved serviceable in practice, owing to a portion of the sodium
amalgam being decomposed almost as quickly as produced with formation of
hypochlorite etc.
Careful inquiry into the causes of this disturbing effect has shown that the
amalgam only promotes decomposition of the water at those points not opposite to
the anode; whereas, on the contrary, a considerable concentration takes place when
the whole surface of the amalgam, under the action of the current, is as it were
overshadowed by the anode surface; or in other words when the density of the
current is equal at all parts of the mercury.
It is upon this discovery that the arrangement of the anode in the electrolytic
cell, as hereinafter described, is based.
(b) The employment of a rotary or whirling mercury cathode.
All similar apparatus hitherto proposed offer the drawback that the amalgam
floating on the surface of the mercury which is comparatively rich in sodium,
cannot without difficulty be removed from the electrolytic cell.
By the employment of a rotary or whirling cathode as subsequently described,
the amalgam is drawn into the vortex and in this manner continually removed from
the cell.
(c) Precise measurement and observation have shown that the period occupied
by the amalgam in parting with its sodium to the water or the nitrate solution is

page_text: •
.
about five times greater than that separating the sodium and required for
electrolytically effecting its absorption by the mercury under the action of the
current.
According to this invention the amalgam is distributed over a large surface to
prevent its absorbing more sodium than would be consistent with facility in
carrying out the process and in this condition it is subjected to the action of the,
preferably hot, decomposing liquid. The mercury becomes freed from most of the
sodium being subsequently cooled and dried before its re-entrance into the decom-
posing cell.
By the operations herein described the formation of any hypochlorite
in the electric cell is avoided, while at the same time practically the whole of the
sodium contained in the mercury is separated therefrom, and the latter metal
restored to the condition in which it is again capable of absorbing sodium. The
accompanying drawings illustrate an arrangement of apparatus suitable for carrying
out the improved process in practice.
Fig. 1 is a central longitudinal section of the apparatus, and
Fig. 2 is a plan thereof.
As shewn the arrangement comprises an electrolytic decomposing apparatus or
ressel I from which a pipe II conducts the amalgam into a second vessel III where
it is decomposed. The mercury flowing from this vessel passes through the cooling
apparatus IV into the vessel V from which it is forced by a pump VI along a
pipe VII, back into the electrolytic decomposing vessel I. VIII is a reservoir
containing the solution of nitrate of sodium and IX a vessel provided with a pump
for storing the electrolyte.
The electrolytic decomposing apparatus I comprises a casing A of suitable
material such as wood or cement, the cover or lid D of which carries a pipe E for
the discharge of the chlorine gas, while at the lowest point of its bottom K there is
.provided an outlet M for the amalgam formed. The funnel-shaped bottom of the
apparatus is provided with a helical projecting rib which causes the mercury C,
forced in at N, to take a spiral course as it moves from the circumference towards
the centre of the bottom, so that it rapidly gyrates and falls into the funnel T with
a whirling movement.
The anode is comprised of carbon or platinum plates B arranged horizontally and
in juxtaposition to each other. Between the wall of the reservoir and the anode a
narrow space or interstice L is left through which the electrolyte rises (past the
anodes) after having been admitted into the vessel underneath the anode plates and
passed rapidly over the mercury. The anode is connected with the source of current
by the wire p and the cathode by the wire n.
The solution of common salt is forced by means of a pump, from the vessel IX,
into the decomposing vessel which it enters at G. Opposite to this point G there
is provided a projecting piece or rib F at the bottom of the vessel arranged
so as to leave only a narrow space underneath the anode plates, through which
space the electrolyte is forced thereby somewhat powerfully washing the anode
. plates below and carrying away any bubbles of chlorine gas which may be adhering
to them.
The electrolyte flows through the space or slot L to the upper portion of the
vessel and into the pipe H by which it returns into the vessel IX, where it is
enriched and by means of the pump made to resume its circuit through the decom-
posing apparatus. The chlorine gas escapes from the reservoir A and is conveyed
by the pipe E to any required place. The amalgam simultaneously formed issues
at M and passes through the pipe II into the second vessel III. This vessel
preferably comprises a chamber a made of material such as stone or cement, the
inclined bottom surface of which is lined with corrugated sheet iron as at b. A
short distance therefrom and parallel to it, a grate d gilt, silvered or platinum-
plated is suspended from wires 7, this grate serving as one electrode of one of the
elements or cells of the battery, the other being formed by the layer or current of
amalgam-admitted-at C. The vessel or chamber III is tightly closed by means of
a cover k the edges of which enter grooves filled with water; it receives solution

page_text: of nitrate of sodium from the vessel VIII through the pipe g such solution being
heated by steam supply through the pipe h.
The
The amalgam flowing over the inclined bottom is decomposed into hydroxide of
sodium and mercury by the hot aqueous solution of nitrate of sodium.
hydrogen simultaneously formed exercises a decomposing action upon the nitrate of
sodium in solution, hydroxide of sodium and ammonia being obtained. The ammonia
escapes through the pipe fleading to condensing apparatus where it collects as a
highly valuable solution of pure ammonia, while the dissolved caustic soda is
drawn off at m and the mercury discharged at the lowest point e of the inclined
bottom.
The heat set free during the decomposition of the amalgam is converted into
electric energy which is conducted away from the amalgam electrode and the
electrode d by wires n' and p' for performing any suitable work but preferably for
relieving the electric generator used in connection with the electrolytical decom-
posing vessel I.
The heated mercury issuing at e after being cooled within the coil IV, passes
into the vessel V from which it is forced back by the pump VI and along the
pipe VII, into the electrolytic decomposing apparatus which it enters at the
point N of the periphery of the funnel shaped bottom K. It will thus be seen
that the mercury although continually circulating is either confined in closed
pipes or covered by a layer of liquid whereby any loss of this valuable product is
avoided.
Dated this 14th day of Jule 1803
C. KELLNER,
By L. W., per F. B.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Ammonia, Sodium Hydroxide,
and Chlorine, and in Apparatus therefor.
J, CHARLES KELLNER, of Wasagasse 39 Vienna I Austria, Doctor of Philosophy,
General Manager of the Kellner-Partington Paper Pulp Co., Ltd., do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This invention has for object to convert sodium nitrate into ammonia and sodium
hydroxide. For this purpose an aqueous solution of sodium nitrate, preferably in
a heated state, is treated with a sodium amalgam produced by a continuous process
by the electrolysis of sodium chloride, mercury being employed in such process to
form the cathode.
The chlorine evolved during this electrolytic process may be conducted away and
utilized in any convenient manner. The mercury acts as an important medium by
absorbing and introducing to the nitrate solution the sodium produced by the
electrolytic decomposition of the sodium chloride. The water in the nitrate
solution is thus decomposed by the sodium, the hydrogen evolved acting to reduce
the sodium nitrate to ammonia and sodium hydroxide. After giving off the
sodium it contained the mercury absorbs a further quantity of sodium produced by
electrolysis from the sodium chloride in solution, and is ready for a repetition of
the process.
The whole of the operation proceeds with perfect regularity. By placing an
electrode in the solution of nitrate the mercury forming the other electrode, a
galvanic cell is formed, enabling the heat generated by the chemical decomposition.
to be converted into electrical energy which can be utilised for any suitable purpose
such as for example relieving the source of current employed for decomposing the
sodium chloride.

page_text: The main features of novelty in the process are as follow :-
(a) The employment of an anode (say of platinum or carbon) having a much
larger surface than the mercury opposed to it as a cathode.
By this arrangement an inconvenience which has hitherto attended all processes
in which mercury has been used as a horizontal cathode is avoided, none of these
processes having heretofore proved serviceable in practice, owing to a portion of
the sodium amalgam being decomposed almost as quickly as it was produced, with
formation of an hypochlorite, etc.
Careful inquiry into the causes of this disturbing effect has shown that the
amalgam only promotes decomposition of the water at those points not opposite to
the anode, whereas, on the contrary, a considerable concentration takes place when
the whole surface of the amalgam, under the action of the current, is as it were,
"overshadowed" by the anode surface; or in other words when the density of the
current is equal at all parts of the mercury. It is upon this discovery that the
arrangement of the anode in the electrolytic cell, as hereinafter described, is
based.
(b) The employment of a rotary or "whirling" mercury cathode. All similar
apparatus hitherto proposed offer the drawback that the amalgam coating on the
surface of the mercury, which is comparatively rich in sodium, cannot, without
difficulty, be removed from the electrolytic cell.
By the employment of a rotary or "whirling" cathode, as subsequently:
described, the amalgam is drawn into the vortex and in this manner continually
removed from the cell.
(e) Precise measurement and observation have shown that the period occupied
by the amalgam in parting with its sodium to the water or to the nitrate solution is
about five times greater than that required for electrolytically effecting the
absorption of the sodium by the mercury under the action of the current.
To prevent the amalgam absorbing more sodium than would be consistent with
facility in 'carrying out the process it is according to this invention, distributed
over a large surface, and "in this condition is subjected to the action of the
décomposing liquid which is preferably used in a heated state. The mercury which
thus becomes freed from most of the sodium, is subsequently cooled and dried before
it is returned to the electrolytical decomposing vessel. By the operations herein
described the formation of any hypochlorite in the electric cell is avoided, while at
the same time practically the whole of the sodium contained in the mercury is
separated therefrom, and the latter metal restored to the condition in which it is
again capable of absorbing sodium.
The drawings filed with my Provisional Specification illustrate an arrangement
of apparatus suitable for carrying the improved process into practice.
In the said drawings,
Fig. 1 is a central longitudinal section partly in elevation, of the apparatus, and
Fig. 2 is a plan thereof."
F
The apparatus shown comprises an electrolytic decomposing apparatus I from
which a pipe II conducts the sodium amalgam into a vessel III where it is decom-
posed. The mercury flowing from this vessel passes through the cooling
apparatus IV into the vessel V from which it is forced by a pump VI along a
pipe VII, back into the electrolytic décomposing apparatus f. VIII is a reservoir
containing the solution of sodium nitrate and IX is a vessel provided with a pump
for storing the electrolyte used in the apparatus I.
The electrolytic decomposing apparatus I comprises a casing A of suitable
material such as wood, cement, the cover or lid D of which carries a pipe E for
the discharge of the chlorine gas, while at the lowest point of its bottom K there
is provided an outlet M for the amalgam formed. The funnel-shaped bottom o
the apparatus is provided with a helical projecting rib as shown in Fig. 2, which
causes the mercury C, forced in at N, to take a spiral course as it moves from.the
circumference towards the centre of the bottom, so that it rapidly gyrates and falls
into the funnel T with a whirling movement.

page_text: The anode is composed of carbon or platinum plates B arranged horizontally
and in juxtaposition to each other. Between the wall of the vessel A and the
anode a narrow space or passage L is left at one side of the vessel through which
the electrolyte rises after having been admitted into the vessel underneath the
anode plates and passed rapidly over the mercury cathode. The anode and
cathode are connected with the positive and negative poles respectively of an
electric generator by the wires P and n.
The solution of common salt is forced by means of a pump as shown from the
vessel IX, into the decomposing vessel A which it enters at G. Opposite to this
point G there is provided a projecting piece or rib F which is so arranged at the
bottom of the vessel as to leave only a narrow space underneath the anode plates,
through which space the electrolyte is forced, so as to somewhat powerfully wash
the underside of the anode plates and carry away any bubbles of chlorine gas
which may be adhering to them.
1
The electrolyte then flows through the space or passage L to the upper portion
of the vessel A and into the pipe H by which it returns to the vessel IX, where it
is enriched, and by means of the pump is made to resume its circuit through the
decomposing apparatus. The chlorine gas escapes from the reservoir A and is
conveyed by the pipe E to any required place. The sodium amalgam simultaneously
formed issues at M and passes through the pipe II into the second vessel III.
This vessel preferably comprises a chamber a made of material such as stone or
cement, the inclined bottom surface of which is covered with corrugated sheet iron
A short distance therefrom and parallel to it, a grate d, gilt, silvered or
platinum-plated, is suspended from wires ; this grate serving as one electrode of
an electric element or cell, the other electrode being formed by the layer or current
of sodium amalgam admitted at C. The vessel or chamber III is tightly closed
by means of a cover k the edges of which enter grooves filled with water; it
receives a solution of sodium nitrate from the vessel VIII through the pipe g,
such solution being heated by steam supplied through the pipe h.
as at b.
The sodium amalgam flowing over the inclined bottom of the vessel III is
decomposed into sodium hydroxide and mercury by the hot aqueous solution of
nitrate of sodium, the hydrogen simultaneously formed exercising a decomposing
action upon the sodium nitrate in solution whereby sodium hydroxide and ammonia
are produced. The ammonia escapes through the pipe which conducts it to
condensing apparatus where it collects as a highly valuable solution of pure
ammonia, while the dissolved sodium hydroxide or caustic soda is drawn off
at m and the mercury discharged at the lowest point e of the inclined bottom b of
the vessel III.
The heat developed during the decomposition of the sodium amalgam is .con-
verted into electric energy which is conducted away from the amalgam electrode
and the electrode d, by wires n¹ and p' for performing any suitable work, but
preferably for relieving the electric generator used in connection with the
electrolytical decomposing vessel I.
The heated mercury issuing at e, after being cooled within the coil IV, which
may be immersed in a cooling fluid such as water, passes into the vessel V, from
which it is forced back by the pump VI and along the pipe VII, into the
electrolytic decomposing apparatus I which it enters at the point N, of the
periphery of the funnel-shaped bottom K. It will thus be seen that the mercury
although continually circulating is either confined in closed pipes or is covered by
a layer of liquid, whereby any loss of this valuable product is avoided.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described process for the manufacture or production of ammonia,
sodium hydroxide and chlorine by electrolytically decomposing sodium chloride
using mercury as a cathode whereby chlorine and sodium amalgam are formed, and

page_text: 19
+
bringing the sodium-amalgam into contact with an aqueous and preferably heated
solution of sodium nitrate in the presence of an electrode, whereby ammonia and
sodium hydroxide are formed as set forth.
2. In carrying out the process referred to in the preceding claim, distributing
the sodium amalgam where it comes in contact with the solution of sodium nitrate,
over a surface, that is much larger than that of the mercury cathode in the electro-
"lytical decomposing apparatus substantially as herein described for the purpose
specified.
3. In carrying out the process referred to in Claim 1, cooling and drying the
mercury after removal of sodium therefrom as set forth, before returning it to the
electrolytic decomposing apparatus, substantially as described.
4. In carrying out the process referred to in Claim 1, an electrolytic decomposing
apparatus I having the anode B of larger surface than the mercury cathode C
opposed to it, substantially as herein described for the purpose specified.
5. In electrolytic decomposing apparatus of the kind referred to in Claim 4, a
mercury cathode C having a rapid gyratory or whirling motion substantially as
herein described for the purpose specified.
6. Apparatus for the manufacture of ammonia, sodium hydroxide, and chlorine,
constructed arranged and operating substantially as described and shown.
Dated this 7th day of November 1893.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.