Improvements in the Process of and Means for the Manufacture of Cellulose with the Aid of the Electric Current.
Year: 1890

page_text: Date of Application, 9th Apr., 1890
Complete Specification Left, 12th May, 1890--Accepted, 12th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in the Process of and Means for the Manufacture of
Cellulose with the Aid of the Electric Current.
I, CARL KELLNER, of Bartensteingasse 8, Vienna I Austria, Chemist, do hereby
declare the nature of this invention to be as follows:-
According to the process, which forms the subject of my British Patent No. 15,942
of 6th December 1886, vegetable materials from which cellulose is to be obtained
are heated in closed vessels with solutions of metallic chlorides, and an electric
current is caused to pass through the said solutions.
While working this process, I have found that the aid of heat and the employment
of closed vessels may be dispensed with, if the wood is previously reduced to shavings,
or the ions are conveniently concentrated.
As in carrying out the process in this modified way, it is no longer possible to
utilize the different temperatures of the liquid for producing the necessary circulation
of the same the arrangement of the apparatus must also be suitably altered.
According to the modified arrangement of apparatus the solution of which the
agents for the decomposition of the incrusting substances are to be obtained by
electrolysis, is forced up by means of a pump into the receptacle enclosing the
electrodes and whence the ions flow into the bottom portion of the vessels con-
taining the raw material, of which cellulose is to be obtained. The liquid flowing
over the brim of the said vessels passes through sieves into spaces communicating
with the suction pipes of the pump, and thus both ions are recombined within the
pump or in a mixing tank interposed between the decomposing vessels and the
suction pipe of the pump.
In the cases of a higher degree of concentration having to be given to the solutions
of the ions, several electrolyzing apparatus are connected in a series in such a manner
that the anion and the cation coming from a first electrolyzing apparatus are each
electrolytically divided again in a special series of other apparatus from which the
waste ions formed are conveyed back to the pump.
In order to enable my invention to be fully understood, 1 shall hereinafter
decribe the same with reference to the annexed drawings, in which
Fig. 1 is a sectional elevation of an apparatus for the manufacture of cellulose in the
electrolytic manner, without the aid of heat, in open vessels.
Figs. 2 and 3 are a horizontal sertion and vertical cross section respectively of the
electrolyzing apparatus.
Fig. 4 shews in elevation a number of electrolyzing apparatus, connected in two
series for the purpose of concentrating the ions.
1
Referring to Figs. 1, 2 and 3, it will be seen that the electrolyte is forced up by a
pump A into the bottom chamber b of a receptacle B, which it enters through:
number of apertures. The said electrolyte consists of a solution of common salt, to
which hydrochloric acid or nitrate, sulphate, carbonate or hydroxide of potassium or
sodium may be added. From the chamber 6 the electrolyte rises through a sieve b¹
into the upper chamber 62, the top portion of which is divided by partial partitions
In each
extending from the top downward, into a number of open bottomed cells.
such cell, an electrode C is suspended, these electrodes being made of carbon, zinc,
platinum, platinized china or any other material, which will not be attacked by the
ions, and all electrodes of the even cells being electrically connected to one pole of the
current generator, while the electrodes of the odd cells are connected to the other pole.
For the separate conveyance of the ions which collect in the cells, round the top
portions of the electrodes, pipes, B¹ B² are provided on the front and rear edges of the
top side of the receptacle B, either of these pipes communicating with all cells wherein

page_text: positive electrodes are mounted, and the other pipe with all the cells containing negative
electrodes.
Through pipes D, connected with the pipes B1 and B2, the anion is made to pass
into one and the cation into the other of two decomposing vessels, which have
previously been filled with wood shavings subdivided by suitable means such as a chaff
cutting engine. It will be found advantageous to impregnate the said wood
shavings with a solution of the electrolyte before subjecting them to the action of the
ions. After having acted in the decomposition vessels, the solutions of the ions are
conveyed through pipes E into a collecting reservoir a, which is connected with the
suction pipe of the pump A and contains an agitator. In the said collecting tank a,
the anion and cation unite again, and the pump A forces the combined liquid anew
into the electrolyzing apparatus B.
When larger pieces of wood or other non-subdivided materials are to be worked into
cellulose, by treating them with concentrated ions, without the aid of heat and in open
vessels, a number of electrolyzing apparatus are, as already stated, so connected as to
form two series in the manner shewn by fig. 4.
In fig. 4, F, F1, F2, F3, F4 are electrolyzing apparatus of identical arrangement.
The body or enclosing vessel f of each such apparatus may be made of zinc and fulfil
the office of the positive electrode or anode, at which the electro-negative element or
anion is evolved, while a carbon pencil f¹ serves as the negative electrode or cathode;
this carbon rod is surrounded by an open bottomed tube f of non-conducting
porous material, for instance hexanitro cellulose.
In the arrangement shown the cation separated in the electrolyzing apparatus F
passes through the pipe g into the electrolyzing apparatus F1, while the anion is
conveyed through the pipe into the electrolysing apparatus F2. Within the
apparatus F, another portion of the electro-negative elements yet contained in the
liquid forced into it is separated and caused to pass through a pipe ¹ into a pipe j, which
runs back to the electrolyte reservoir a, while the concentrated cation rises through
the pipe g¹ into the apparatus F³.
In the same manner, another portion of the electro-positive elements is eliminated
from the anion, which has passed through the pipe h into the apparatus F. The
said electro-positive elements flow through the pipe ginto the return pipe j, while
the concentrated anion passes through the pipe h into the apparatus F³, to be still
more concentrated therein, as the cation is in F³ and so on.
It is obvious that any greater number of electrolyzing apparatus may be con-
nected to form a system in the way described according to the desired degree of
concentration.
When using the highly concentrated solutions obtained with the aid of such
systems of apparatus, it is not necessary to cause the ions constantly to pass through
a given quantity of the material to be worked into cellulose. On the contrary, one
may in this case form a battery of a certain number of pairs of decomposing
vessels, in such a manner that the contents of a given number of pairs of vessels
are always subjected to the action of the anion and cation, while in one pair of
vessels the ready product is being discharged and fresh raw material filled in, and
in another pair of vessels the agents prepared by electrolysis are allowed to flow
in. Moreover all the decomposing vessels may be connected with one another like
the diffusers in sugar manufactories, in order to afford possibility for causing the
said agents, after having allowed them to act during a given time upon the contents
of one vessel, to pass into another vessel. In this latter case, the freshly prepared
decomposing liquids are conveyed into those vessels in which the decomposition has
already most progressed, whilst the raw material freshly filled into decomposing
vessels is brought together with solutions, which have already acted in all vessels
of the battery and which are afterwards to be carried back into the recombining
tank a.
When more or less large pieces of wood are treated in the described way, layers
of snow white cellulose are gradually laid open on the surface of the pieces, while
the cores still preserve the woody character.

page_text: In order to avoid weakening this uncovered cellulose by any longer action of the
decomposing agents, the same is loosened from the wood at the rate of its formation
by energetic stirring of the mass, and it is carried upward by an active current of the
liquid; thus the formed cellulose is carried along by that portion of the liquid,
which gradually flows over the brim of the vessel containing the raw material.
The top portion of the sides of a second vessel surrounding the former is provided
with fine perforations in the manner of pulp strainer plates, and the cellulose thus
gets into a sieve apparatus, whence the liquid separated therefrom, flows back into
the recombining tank.
The decomposing vessels, shewn in Fig. 1, are provided with an arrangement for
this purpose.
The large pieces of wood are filled into the middle vessel K, the bottom of
which is provided with an aperture k for admitting the decomposing liquid. The
said liquid arrives through pipe D from the electrolyzing apparatus B and enters the
lowermost part of a vessel which concentrically encloses the vessel K and
somewhat overtops it. For the sake of uniform distribution of the entering liquid,
a sieve-bottomed k² is arranged above the inlet. A screw agitator L projects into
the bottom aperture of the vessel K for creating in the liquid an ascending or
descending current and stirring up the whole contents of the vessel. The said current
carries along the cellulose separated from the wood, and as, in consequence of the
continuous How of liquid through pipe D there is also a continuous overflowing, the
cellulose is carried out of the vessels through the top portion ³ of vessel k¹, which is
perforated like pulp strainer plates.
The overflowing liquid with the cellulose suspended therein passes into a casing *,
which su rounds the vessel k' and is closed a small distanco below the perforated top
portion of the sides of vessel k¹. From the annular spaces of both casings k, the
liquid and cellulose flow through siphon pipes m into revolving conical sieve drums M,
below which inversely inclined gutters m¹ are arranged. At the wider ends of the
conical sieve drums M, the cellulose is discharged in a pulpy state, while the liquid
passing through the sides of the drums into the gutters m³ flows thence through
pipes E into the recombining tank a.
The casing is provided with a sealed cover N and the vessel k¹ has a discharge
tube formed at the bottom. The pipe a passing through the cover N is intended for
the introduction of steam, when the mass is to be heated, while the pipe n' allows
evolved gases to escape.
In the case of decomposing vessels, which are connected, as hereinbefore described,
to form a battery, similar to diffusion-batteries, the separated cellulose may be
removed from time to time either from all decomposing vessels or from that vessel
only, which, for the time being, is the last of the cycle. It will be readily understood
that the electrolyzing apparatus may be interposed between the decomposing-vessels
without departing from the nature of this invention.
Investigations as to the nature of the alterations undergone by the incrusting
substances in the course of this process, have shewn that different degrees of
oxidation are formed under the hydrogen absorbing action of the chlorine, and that
the least oxidized compounds are soluble in alkalies the medium ones in water or
neutral liquids, and the highest in acid liquids.
This fact enables cellulose to be made with the aid of electrolysis at very little
expenditure of power. It is necessary indeed, to often reverse the direction of the
current in electrolyzing apparatus to first cause feebly oxidized compounds to be formed
by a short action of chlorine and afterwards dissolve these compounds by the soda lye.
On being passed along the electrode, these compounds are decomposed into carbonic
acid and water.
100s
W. LLOYD WISE,
Per F. J. Brougham,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in the Process of and Means for the Manufacture of
Cellulose with the Aid of the Electric Current.
I, CARL KELLNER, of Bartensteingasse, 8, Vienna I, Austria, Chemist, do hereby
declare the nature of this invention and the manner in which the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
-
According to the process, which forms the subject of my British Patent No. 15,942
dated 6th December 1886, vegetable materials from which cellulose is to be obtained,
are heated in closed vessels with solutions of metallic chlorides, and an electric
current is caused to pass through the said solutions.
While working this process, I have found that the aid of heat and the employment
of closed vessels may be dispensed with if the wood be previously reduced to a
subdivided state for example to shavings, or if the ions produced by electrolysis be
in a concentrated state.
As in carrying out the process in this modified way, it is no longer possible to
utilize the different temperatures of the liquid for producing the necessary circulation
of the same, the arrangement of the apparatus must also be suitably altered.
According to the modified arrangement of apparatus, the solution of which the
agents for the decomposition of the incrusting substances are to be obtained by
electrolysis, is forced up by means of a pump, into the receptacle enclosing the
electrodes, whence the ions flow into the bottom portion of the vessels containing
the raw material, from which cellulose is to be obtained. The liquid flowing over the
brim of the said vessels passes through sieves into spaces communicating with the
suction pipes of the pump, and thus both ions are recombined within the pump or in
a mixing tank interposed between the decomposing vessels and the suction pipe of
the pump.
In the case of a higher degree of concentration having to be given to the
solutions of the ions, several elctrolyzing apparatus are connected in a series in
such a manner that the anion and the cation coming from a first electrolyzing
apparatus are each electrolytically divided again, in a special series of other apparatus
from which the waste ions formed are conveyed back to the pump.
In order to enable my invention to be fully understood, I will now proceed to
describe the same with reference to the drawings filed with my Provisional Specifica-
tion in which
Fig. 1 is a sectional elevation of an apparatus for the manufacture of cellulose in
an electrolytic manner in open vessels, without the aid of heat.
Figs. 2 and 3 are a horizontal section and vertical cross section respectively, of the
electrolyzing apparatus.
Fig. 4 shows in elevation a number of electrolyzing apparatus, connected in two
series for the purpose of concentrating the ions.
Referring to figs. 1, 2 and 3, it will be seen that the electrolyte is forced up by a
pump A into the bottom chamber b of a receptacle B, which it enters through a
number of apertures. The electrolyte consists of a solution of common salt, to
which hydrochloric acid or nitrate, sulphate, carbonate or hydroxide of potassium
or sodium may be added. From the chamber the electrolyte rises through a
perforated plate 6' into the upper chamber 62, the top portion of which is divided by
partial partitions extending from the top downward, into a number of open bottomed
cells. In each such cell, an electrode is suspended, these electrodes being made of
carbon, zinc, platinum, platinized china or any other suitable material, which will not
be attacked by the ions; the electrodes of the even numbered cells are electrically
connected to one pole of the electric generator, while the electrodes of the odd cells
are connected to the other pole. For the separate conveyance of the ions which
collect in the cells, round the top portions of the electrodes, pipes B¹ B² are provided
1

page_text: on the front and rear edges of the top side of the receptacle B, either of these pipes
communicating with all the cells, wherein positive electrodes are mounted, and the
other pipe with all the cells containing negative electrodes.
Through pipes D, connected with the pipes B1 and B2, the anion is made to pass
into one and the cation into the other of two decomposing vessels, which have
previously been filled with wood shavings, subdivided by suitable means such as a
chaff cutting machine. It will be found advantageous to impregnate the said wood
shavings with a solution of the electrolyte before subjecting them to the action of the
ions. After having acted in the decomposition vessels, the solutions of the ions are
conveyed through pipes E into a collecting reservoir a, which is connected with the
suction pipe of the pump A, and contains an agitator. In the said collecting tank a,
the anion and cation unite again, and the pump A again forces the combined liquid
into the electrolyzing apparatus B.
When larger pieces of wood or other materials not subdivided are to be worked
into cellulose, by treating them with concentrated ions, without the aid of heat and
in open vessels, a number of electrolyzing apparatus are, as already stated, so con-
nected as to form two series in the manner shewn in Fig. 4. In this Fig. É, F¹, F³,
F3, F4 are electrolyzing apparatus of identical arrangement. The body or enclosing
vessel of each such apparatus may be made of zinc and fulfil the office of the
positive electrode or anode, at which the electro-negative element or anion is evolved,
while a carbon pencil serves as the negative electrode or cathode; this carbon
rod is surrounded by an open bottomed tube f of non-conducting porous
material, for instance hexanitro-cellulose.
In the arrangement shown the cation separated in the electrolysing apparatus F
passes through the pipe g into the electrolyzing apparatus F', while the anion is
conveyed through the pipe into the electrolyzing apparatus F2. Within the
apparatus F1, another portion of the electro-negative elements still contained in the
liquid forced into it, is separated and caused to pass through a pipe h¹ into a pipe j,
which runs back to the electrolyte reservoir while the concentrated cation rises
through the pipe g' into the apparatus F³.
In the same manner, another portion of the electro-positive elements is eliminated
from the anion, which has passed through the pipe h into the apparatus F2. The said
electro-positive elements flow through the pipe 9 into the return pipe j, while the
concentrated anion passes through the pipe into the apparatus F to be still more
concentrated therein, as the cation is in 3 and so on.
It is obvious that a greater number of electrolyzing apparatus than that shown
may be connected to form a system in the way described, according to the degree of
concentration desired.
When using the highly concentrated solutions obtained with the aid of such
arrangements of apparatus, it is not necessary to cause the ions constantly to pass
through a given quantity of the material to be worked into cellulose. Thus a battery
of a certain number of pairs of decomposing vessels may be used in such a manner
that the contents of a given number of pairs of vessels are always subjected to the
action of the anion and cation, while in one pair of vessels the ready product is being
discharged and fresh raw material filled in, and in another pair of vessels the agents
prepared by the electrolysis are allowed to flow in. Moreover, all the decomposing
vessels may be connected with one another like the diffusers in sugar manufactories,
in order to afford possibility for causing the said agents, after having allowed them
to act during a given time upon the contents of one vessel, to pass into another vessel.
In this latter case, the freshly prepared decomposing liquids are conveyed into those
vessels in which the decomposition has already taken place to the greatest extent,
whilst the raw material freshly filled into decomposing vessels is brought into contact
with solutions, which have already acted in all the other vessels of the battery, and
which are afterwards to be conveyed back into the recombining tank a.
When large pieces of wood are treated in the manner described, layers of snow-
white cellulose are gradually formed on the surface of the pieces, while the cores still
preserve the woody character.

page_text: In order to avoid weakening of this uncovered cellulose by prolonged action of the
decomposing agents it is loosened from the wood as it is formed by energetic stirring
of the mass, and it is carried upward by an active current of the liquid; thus the
formed cellulose is carried along by that portion of the liquid which gradually flows
over the brim of the vessel containing the raw material. The top portion of the sides
of a second vessel surrounding the former is provided with fine perforations in the
manner of pulp strainer plates, and the cellulose thus passes into a sieve apparatus,
whence the liquid separated therefrom, flows back into the recombining tank.
The decomposing vessels, shewn in Fig. 1, are provided with an arrangement for
this purpose.
The large pieces of wood are filled into the middle vessel K, the bottom of which
is provided with an aperture k for admitting the decomposing liquid. The said liquid
arrives through the pipe D from the electrolyzing apparatus B and enters the lower-
most part of a vessel which concentrically encloses the vessel K and extends
upward to a greater height than such vessel. For the sake of uniform distribution of
the entering liquid, a sieve bottom 2 is arranged above the inlet. A screw agitator L
projects into the bottom aperture k of the vessel K for creating in the liquid an
ascending or descending current and stirring up the whole contents of the inner
vessel. The said current carries along the cellulose separated from the wood, and as,
in consequence of the continuous flow of liquid through the pipe D, there is also a
continuous overflowing, the cellulose is carried out of the vessels through the top
portion of the vessel k¹, which is perforated like pulp strainer plates and serves to
retain unconverted material.
The overflowing liquid with the cellulose suspended therein passes into a casing k*,
which surrounds the vessel k' and is closed a small distance below the perforated top
portion of the sides of vessel k¹. From the annular spaces of both casings ', the
liquid and cellulose flow through siphon-pipes m into revolving conical sieve drums M,
below which inversely inclined gutters m are arranged. At the wider ends of the
conical sieve drums M, the cellulose is discharged in a pulpy state, while the liquid
passing through the sides of the drums into the gutters m¹ flows thence through
pipes E into the recombining tank a.
Each casing k is provided with a sealed cover N and the vessel k¹ has a discharge
tube formed at the bottom. is a pipe that passes through the cover N and serves
for the introduction of steam for warning the liquid in decomposing vessel ¹ to the
ordinary temperature, when such liquid is supplied in a very cold state, as in winter.
The steam is not intended to boil the liquid which may when necessary be warmed in
a vessel external to the decomposing vessel k¹. n¹ is a pipe that allows evolved gases
to escape to the atmosphere and renders the decomposing vessel practically an open
one, that is to say one in which the pressure is the same as that of the external
atmosphere.
In the case of decomposing vessels, which are connected as herein before described,
to form a battery similar to diffusion-batteries, the separated cellulose may be removed
from time to time either from all the decomposing vessels or from that vessel only,
which, for the time being, is the last of the cycle. It will be readily understood that
the electrolyzing apparatus may be interposed between the decomposing vessels
without departing from the nature of this invention.
Investigations as to the nature of the alterations undergone by the incrusting sub-
stances in the course of this process, have shewn that different degrees of oxidation
are formed under the hydrogen absorbing action of the chlorine, and that the least
oxidized compounds are soluble in alkalies, the medium ones in water or neutral
liquids, and the highest in acid liquids.
This fact enables cellulose to be made with the aid of electrolysis with very little
expenditure of power. It is only necessary to often reverse the direction of the
current in the electrolyzing apparatus to first cause feebly oxidized compounds to be
formed by a short action of chlorine and afterwards to dissolve these compounds by
the soda lye. On being passed along the electrodes, these compounds are décomposed
into carbonic acid and water.

page_text: Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I
claim is :-
1. In the herein described process for the manufacture of cellulose with the aid of
electrolysis from wood shavings or other subdivided vegetable materials the use of
open decomposing vessels without heating appliances substantially as described.
2. In the herein described process for the manufacture of cellulose with the
aid of electrolysis the use of open decomposing vessels without heating
appliances, with apparatus for concentrating the decomposing liquids by repeated
electrolysis.
3. In the herein described process for the manufacture of cellulose with the aid of
electrolysis, the continuous separation of the cellulose formed on the surface of the
raw material, this separation being effected by stirring the mass and creating in the
liquid an active current, which carries the cellulose along through a perforated
partition that retains larger and unconverted material.
4. In the herein described process for the manufacture of cellulose with the aid of
electrolysis, the impregnation of the raw vegetable material with a portion of the
electrolyte, previous to its being acted upon by the ions.
Dated this 12th day of May 1890.
C. KELLNER,
Per L. W.