PROCESS AND APPARATUS FOR THE MANUFACTURE OF CELLULOSE AND GLUCOSE FROM WOOD AND OTHER VEGETABLE PRODUCTS
Year: 1884

page_text: I, ADOLPH BEHR, Chemist, of Coethen, in the German Empire, do hereby declare
the nature of said invention for "PROCESS AND APPARATUS FOR THE MANUFACTURE
OF CELLULOSE AND GLUCOSE FROM WOOD AND OTHER VEGETABLE PRODUCTS," to
be as follows:-
10
Hitherto Cellulose (C, H₁。 О, specific gravity 1.525) has been produced for
technical purposes from wood by extracting the admixtures, such as oils, resin, wax,
salts, gum and tannic acid, by means of sodic hydrate.
About 20 per cent of the sodic hydrate used in this process are lost and the
recovering of the 80 per cent causes great loss of time, coal and lime.
My new process has for its object the cheap production of pure cellulose without
waste and so as to convert into glucose as much as possible of the admixtures
consisting chiefly of carbohydrates, as well as the waste wood fibres.
For this purpose the wood of the stems is carefully cleaned from marrow and
bark, split and cut into uniformly thin discs or shavings.
The latter are allowed to drop upon a drying floor, and subsequently upon a
second drying floor composed of perforated iron plates which are heated from below
by a system of pipes filled with water of condensation.
The hot air rises from the floor into the drying chambers, takes up moisture
from the wood and escapes through a number of flat rectangular flues to the
chimney.
If the wood is to be subsequently treated with alcohol, any oil of turpentine
contained in the wood must be removed, which is effected by distillation at a
temperature of 160 degrees Celsius, and by means of a special apparatus situated
below the floor on which the wood is cut into pieces.
This apparatus chiefly comprises an iron cylinder containing a stirrer and
surrounded at its lower half by a jacket in which circulates steam during the
distillation. This cylinder receives the slices of wood from a shoot provided in the
floor of the cutting room. For the subsequent drying of the wood, water of
condensation produced in steam coils, may be used. The interior of the cylinder is
also supplied with steam by a row of curved pipes which follow the inner wall of
the cylinder and occupy about a quarter of its circumference. The oil of turpentine
evaporated in the cylinder, escapes with the steam into a cooler, where the vapours,
[Price 8d1

page_text: of oil and water are condensed, and from which the product of condensation is led
to a collecting tank.
Before entering the latter, the distillate passes through an intermediate vessel
hermetically closed by a hemispherical glass through which the attendant may
observe the quantity and condition of the distillate. As soon as the latter has
ceased to contain oil of turpentine, the direct admission of steam is stopped, and air
is allowed to enter the cylinder, which air comes in contact with the particles of
wood, is thereby saturated with water, and then allowed to escape to the chimney.
For dissolving the resin, either hydrocarbons or alcohols may be employed.
Among hydrocarbons I prefer to use oil of turpentine (C₁, H₁₁) and among
alcohols, I choose fusel oil, which is a mixture of propylalcohol (C, H, O), Butyl-
alcohol (C. H₁ O) and Amylalcohol (C, H₁, O), and has a specific weight of 0.811.
A specially constructed apparatus, hereinafter called the wood-boiler, is filled
two-thirds with the dry wood shavings and then supplied with oil of turpentine or
fusel oil by means of a pump, until the liquid just covers the wood. The boiler
contains a pipe coil in which circulates steam for raising the temperature of the
boiler slightly above the boiling point of the liquid used for extraction. The
temperature is kept low and the escape of oil vapours prevented by a condenser
situated at the top of the boiler and which consists of a pipe surrounded by cold
water. The greatest part of the oil vapours penetrating into this pipe is condensed
and drops back into the boiler.
-
10
Any oil vapours which pass through the condenser are completely condensed in
a second condenser, and conducted back into the oil receptacle through an inter-
mediate vessel provided with a glass cover for observation.
After the complete dissolution of the resin contained in the wood tissue the
brothy mass is let off into the extraction cylinder placed at a lower level, and
containing a perforated false bottom, covered with wire gauze or netting which
affords a passage for the resinous solution. Any liquid, which may remain in the
wire cloth, is pressed out by steam. After all resin and oil has been removed from
the cloth and conducted into the clarifying vessel, so that only watery liquid flows
through the sieve, the wood stuff is exposed for some time to the action of steam or
water so as to dissolve also the extractive matter of the wood, and carry it to the
clarifying vessel. The vapours formed in this vessel are caught by a hood and
conducted to a cooler, where they are condensed, and the product of condensation is
conducted to a collecting tank.
In the clarifying vessel the resinous solution occupies the top and the water with
the extractive matter the bottom part; the former is let off by overflow cocks into
the suction pipe of a pump which transports the solution to a distilling apparatus.
This apparatus comprises an upright cylinder, containing a steam coil, and
covered by a hood, a cooler with cooling pipe and a collector from which the pure
product of distillation flows back into the tank. The residue in the distilling
apparatus is drawn off and cast into moulds. The aqueous stratum remaining in
the clarifying vessel is drawn off into the collecting tank, which serves to com-
•pletely separate from the aqueous stratum the oil still contained in it. After the
separation is completed, the oil is conducted to a separate tank, while the aqueous
stratum is conducted to another trough from which it is lifted by a pump into a
bigh level reservoir situated above the glucose boiler.
The cellulose remaining on the sieve of the extraction cylinder still contains
carbohydrates and salts insoluble in water, for instance salts of iron which would
render the subsequent bleaching process difficult. All these substances are dissolved
by diluted sulphuric acid, for which purpose the cellulose is drawn out of the
extraction cylinder, lifted up to the first storey of the building and introduced into
the glucose boiler by a suitable shoot.
The necessary quantity of very dilute sulphuric acid is admitted through an
upright tube, the stirring apparatus of the glycose boiler set in action and sufficient
steam admitted to the jacket of the stirring vessel, to produce a slight ebullition of
the whole mass,

page_text: Afterwards the cellulose is conducted back into the extraction cylinder, where
the acid liquid runs off and is allowed to drop into the trough situated under the
said cylinder. The cellulose is now washed with steam, until the water running
off from the same is free of acid.
12
The acid liquid drawn off contains appreciable quantities of glycose Co H₁₂ 06+ aq.
and is subsequently utilized together with the aqueous liquid remaining under the
resinous solution; for this purpose it is pumped from the trough into the high level
reservoir mentioned above.
The cellulose being now finished, may either be immediately transferred to the.
bleaching room, or it may be pressed and dried. All cooling appliances are fed from
a high level water reservoir, which is kept full by a pump.
For certain kinds of paper, cellulose may be employed which has not been
purified to such a high degree as may be obtained by the process above
described.
Such cellulose of inferior quality is produced in the following manner.
The wood cleaned from marrow and bark is converted into fine shavings in the
wood cutting room and placed without further treatment directly into the extracting
cylinder provided for this purpose with a second man hole at the upper end. After
closing the cylinder, high pressure steam (of about 8 atmospheres) is introduced
from above into the apparatus and forced through the shavings, care being taken
to avoid the boiling of the mass.
The high temperature of the steam causes the turpentine contained in the wood
to evaporate (which takes place at a temperature of 156.8° C), during which
operation the resin, which melts already at 135° C, becomes a very thin liquid. .
The steam passing through the shavings carries the resin, oil and other substances
capable of being eliminated by steam of such high pressure, into the clarifying
tank, where the resin and other non volatile substances remain, while the greater
part of the water and oil vapours are condensed in the collecting tank.
After the process is terminated, the steam is cut off, the mass is removed from
the extraction cylinder and introduced directly into the glucose-boiler, where it is
cleaned, in the manner described above, from carbo-hydrates, iron and other
substances, by means of water to which some sulphuric acid has been added.
For the purpose of utilizing the steam as completely as possible a series of
extraction cylinders may be placed side by side so that the steam passes through
one cylinder after the other.
Each extractor is provided with a small cooler serving to examine the cooled
distillate, and each cylinder is also provided at its base with a depositing space in
which the heavy impurities accumulate as far as possible, while the steam discharged
from this mass rises through a pipe secured to the cover of the depositing space and
passes from the first into the second and subsequently into the third and fourth
and so on into the last cylinder, and passes from the same, charged with resin, oil
and carbo hydrates, into the claryfying tank, where the non-volatile substances are
precipitated. If no essential oil is present, the high pressure steam is at once
discharged from the clarifying tank, without being conducted through the collecting
tank, to be otherwise utilized.
For this process only a clarifying and a collecting tank is required.
As mentioned above, before converting the wood into cellulose it must be cleaned
from boughs, bark, marrow and so on.
This waste, as well as the needles, thin boughs and other parts are cut as fine as
possible and placed in a separate glycose boiler. If they contain a sufficient
quantity of essential oil, the latter is in the first instance distilled off by the
apparatus mentioned above.
As mentioned before, the glucose boiler consists of a strong upright iron vessel
surrounded up to three-quarters of its height by an iron jacket and provided with
a stirring apparatus.
The vertical stirring shaft carries several superposed sets of arms, each of which
comprises three radial arms. To each radial arm is attached a series of vertical

page_text: rods, so arranged that none of the rods of the same set turns at the same distance
from the central shaft.
.
Each of these rods carries at the lower end a stirring blade composed of two
triangular pieces of sheet iron so as to form tetreaedrons which are open behind
and below. Some of these stirring blades are bent at the point towards the left
and some towards the right so that one side wall is concave and the other convex.
One arm of each set carries straight blades, the other arm carries blades bent to
the left and the third arm blades bent to the right.
The stirring shaft furthermore carries above these systems of stirring appliances
a stirring arm extending radially from the shaft and bent at a right angle and
continued downward along the cylinder wall as far as the bottom, so as to detach
those parts of the mass which adhere to the walls.
: A cock suitably arranged serves to supply the interior of the cylinder with
steam; and another cock serves to feed the jacket.
As the temperature in the boiler is not sufficient to evaporate sulphuric acid, only
aqueous vapour escapes through the steam dome.
The glucose and woodboilers are furthermore provided with steam cocks for
rinsing the cylinders after the same have been emptied.
Except in the extraction cylinder, no high pressure will be produced in any of
the appliances owing to the condensation apparatus combined with the latter.
The wood waste introduced into the glucose-boiler is poured over with diluted
sulphuric acid and with the contents of the high-level reservoir, and this mixture,
which must always possess the same viscosity, is boiled for several hours at a
temperature of 136° C under continuous stirring.

page_text: I, ADOLPH BEHR, Chemist of Coethen, Germany, do hereby declare the nature of
my invention for PROCESS AND APPARATUS FOR THE MANUFACTURE OF CELLULOSE
AND GLUCOSE FROM WOOD AND OTHER VEGETABLE PRODUCTS, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
Cellulose (C. H₁ O, spec. gravity 1.525) was hitherto produced from wood in
large quantities for technical purposes by lixiviating the incrustations or occluded
substances, such as oils, resin, wax, salts, gum, sugar, mucilage, gelatine, iron,
starch, tannic acid by means of sodic-hydrate.
°
In this way about 20% of the sodic-hydrate is lost, and the 80% recovered.
entails great loss of time, coals and lime.
The object of this invention is to produce as cheaply as possible, and on a large
scale, a pure cellulose capable of being bleached by a process in which nothing is
lost, and the incrustations or occluded substances consisting principally of carbo-
hydrates, and also waste-wood, are converted as far as possible into glucose.
The new material may be taken, either from ordinary leaf-bearing trees or from
coniferous trees; the former afford a softer, shorter fibre, and the latter a firmer,
longer one. The heart of the wood is carefully freed from the pith and bark, split
and reduced in the planing chamber A. into as thin and uniform shavings as
possible.
Wood contains about 20% of water which must be expelled.
This generally takes place in the drying-chamber B B, under A.
The shavings are conveyed to the drying-floor b. b through the trap a, and,
when they are sufficiently dry, pass through the valve o into the real drying-
chamber B.
The bottom of the same d is made of perforated iron plates.
By the passages a. fresh air reaches the space under the drying-room which is
warmed by tubes heated with waste-water. The air passes through the interstices
of the wood into the chambers B, and B, dries the wood and escapes to the chimney
by the flues g. g. If the wood is to be subsequently treated with alcohol, for
instance in the case of fir-wood, the oil of turpentine must be first removed, which
is done by distillation at a temperature of 160° C.
The apparatus C serves for this purpose. By means of the funnel h, the shavings
are packed through the man-hole into the iron cylinder, which is provided with
a stirring apparatus.
The lower part of this cylinder is surrounded by a jacket, and when oil of
turpentine is being drawn off by distillation, steam at 6 atmospheres pressure
circulates between the cylinder and the casing.
For the subsequent drying of the wood the very hot water of condensation from
the cooling worms may be used.
Steam or water enters through the cock I, and escapes through m

page_text: When the man-hole and the cocks n are closed, the taps o are opened, until a
sufficient quantity of steam has been admitted through the tubes p. p.
These tubes lie flat on the cylinder, and the stirring-apparatus causes steam at
6 atmospheres to mingle thoroughly with, and penetrate the wood. The oil of
turpentine is thus driven off (boiling point 156.8° C) and escapes with the steam
through the cocks q and r and the tube s to the cooler t, where the oil of turpentine
and the steam are condensed and from which they flow through the receiver u to
the tank S.
The receiver u, and those mentioned below ( and t₁) are hermetically closed
hemispherical bell-shaped glass vessels. They serve as indicators to the attendant,
because the progress of the operation can be ascertained by the quantity and
appearance of the distilled body passing through the receiver. When no turpentine-
oil, but only water, passes through the receiver u, the steam is cut off from the
casing, the cocks o are shut, and the cocks n and v opened. Fresh air now flows.in
through the cocks n and the flat tubes p. p, comes into contact with the particles
of wood by means of the stirring-apparatus, and is saturated with water, after
which it escapes through the cock v and the tube w to the chimney.
The cylinder is emptied through a small opening z which can be closed by a
valve.
Samples may be taken out during the operation through the small valve y.
The wood, when dry, is raised to the first story by the hoist-D, and delivered at
pleasure through the passage a and a man-hole to the wood-boiler or digester E,
where the resin is to be extracted from it.
The resin can be dissolved by hydro-carbons or alcohol; it is however, advisable
to select a solvent which boils at a high temperature and can be procured as
cheaply as possible..
These conditions are fulfilled by oil of turpentine C, H, boiling point 156.8° C,
specific gravity 0.86, and, among the alcohols. by the fusel-oil which is a

page_text: When the highly heated resinous solution reaches the clearing-pan with steam-
water from the wood-boiler, great tension would result in the clearing-pan owing
to the vaporised oil and steam arising from it, if the vapors intercepted by the
cock could not escape to the cooler k, whence they drip into the collecting-
tank L
The resinous solution settles in the upper part of the clearing-pan T and the
water with the extractive matter in the lower part. The depth of the former can
be ascertained by the gauge glass n₁ and it flows off into the suction-pipe m, by
opening the cocks above the level of the water. It is then conveyed by the
pump d, to the distilling apparatus K.
The latter consists of the cylinder o, with the worm p₁, the cock q₁ the
cooler 81 with the cooling worm r, and the receiver t₁ from which the clear
distilled product flows back into the tank G. The residue in K, light colored
colophonium, is drawn off at u and cast in moulds,
The watery fluid remaining in the clearing-pan T is drawn off at 1, into the
collecting-pan L.
•
It contains principally carbo-bydrates, (also a little turpentine-oil if such has been
used).
The collecting pan serves to effect the complete separation of any remnant of oil
from the watery fluid.
When this separation is complete, the oil is conveyed through the cocks v, and
the tube w, into the pan G. and the watery fluid to the pan P. and by the pump c
to the pan M situated above the glucose-boiler, to be worked up later into glucose.
The cellulose remaining on the sieve h₁ of the extracting cylinder H still
contains carbo-hydrates and salts insoluble in water. In the case of fir-wood, it
contains especially ferruginous salts which would subsequently interfere very much
with the bleaching process.
All these substances are dissolved by dilute sulphuric acid.
For this purpose, the cellulose is withdrawn from the extracting cylinder H,
conveyed by the hoist N to the first story, and introduced into the glucose-boiler O
by the shoot ag.
The requisite quantity of very dilute sulphuric acid is added through the
tube b, the stirring-apparatus c, is set in motion, and sufficient steam is
admitted between the cylinder and the outer casing m, to set the whole mass
gently boiling.
The stirring apparatus is kept in motion during the whole operation.
This operation is intended to free the tissue, as far as possible, from any
incrustations, but must by no means injure or dissolve the cellulose.
The quantity of acid must, therefore, be regulated with the greatest precision.
The time required for boiling depends on the age of the wood.
When sufficiently boiled, the cellulose is conveyed through the tube h, back to
the extracting-cylinder H, where the acid fluid runs off and is conveyed to the
pan P by the cock x₁. The cellulose is now cleansed with steam, until the water
running off is free from acid, which is again tested in the cooler .
13
The acid fluid running off contains an appreciable quantity of glucose
С H₁ О + Aq. and when the glucose is subsequently boiled, this fluid is used
with the watery fluid remaining below the resinous solution; for this reason, it is
also conducted by the pump c, from the pan P to the
M.
pan
The cellulose is then ready and comea, either as it is, to the bleaching chamber,
or it is wrung out and dried.
All the cooling appliances are supplied from an elevated water-cistern R, which
in its turn is fed by the pump b
For certain kinds of paper, cellulose can be used which is not so pure as that
produced by the above process.
Such low-grade cellulose should be produced as follows:
The wood freed from bark, pith &c is reduced to very small chips in the planing
chamber A, and these are conveyed, without previous preparation, direct into the

page_text: .
extracting-cylinder H, which is provided above with a man-hole for this purpose.
When the cylinder is closed, high pressure steam (about 8 atmospheres) is let into
the apparatus from above; and driven through the chips, but no boiling must take
place.
Owing to the high temperature of the steam, the turpentine-oil becomes volatile
(at 156.8° C) whereas the resin, which melts at 135° C, becomes very thin. The
steam tends to penetrate the partitions of the chips and carries off the resin, oil
and other elements, removable by steam of this high temperature, to the clearing
pan T, where the resin or non-volatile substance remains, whereas the greater
portion of the steam and vaporised oil is condensed in the collecting pan L.
J
When the process is complete, the steam is turned off, the mass removed from the
extracting cylinder H, and conveyed direct to the glucose-boiler O, where it is
deprived of the carbo-hydrates, iron &c at about 130° C by means of water, to
which some sulphuric acid has been added, in precisely the same way as before
described.
To utilise the steam as far as possible, a number of extracting-cylinders H are
arranged side by side, so that the steam can pass through them all in rotation. The
steam first reaches the extracting-cylinder which contains the cleanest wood.
This cylinder is numbered 1, and called the Finisher, because the ligneous mass
is cleaned in it as much as is possible by this process. The following cylinder,
whose contents come next in purity to those of the Finisher, is numbered 2, and
80 on.
The purity of the cellulose diminishes as the numbers are higher, and increases
with the low numbers. When N, 1 has been emptied, N, 2 becomes the
Finisher.
Each extracting cylinder H is provided with a miniature cooler i for the purpose
of testing the distilled product.
In like manner each of these cylinders has at the bottom a depositing or couching
chamber in which the heavy or impure portions are, as far as possible, deposited,
while the still active steam, freed from the same, rises through a tube placed in the
cover of the couching-chamber from 1 to 2, 3, 4 and so on to the last of the
extracting-oylinders; at length, laden with resin, oil and carbo-hydrates, it reaches
the clearing-pan T, where the non-volatile substances are deposited. If no ethereal
oil is present, the active steam is at once drawn off from T and otherwise employed
without opening L.
In this case T must be made very strong, and provided with safety valves and
manometers, whereas if T contains ethereal oil, the active steam and vaporised oil,
passing the cooler K,, reach the collecting pan L for the purpose of condensing
the ethereal oil.
For this process, only a clearing and a collecting pan are requisite. The
depositing chamber at the bottom of the extracting cylinder is provided at the
very bottom with a cock or valve and a tube, the last named being connected with
T and L
The cock or valve is opened from time to time, and the heavier substances
in the depositing chamber are drawn off to T and L as may be required.
As mentioned at the outset, the wood must be freed from boughs, bark, pith &c
before being worked up into cellulose.
This waste-wood (cones, thin twigs &c) is reduced as small as possible, and
brought to the glucose-boiler O.
If it contains ethereal oil in sufficient quantity this is extracted by distillation
by means of the apparatus C.
As before stated, the glucose-boiler is a strong, stationary, iron cylinder, sur-
rounded to two thirds of its height by an iron jacket, and provided with a stirring
apparatus.
The vertical stirring-shaft c, is provided with several sets of arms, each con-
sisting of 8 horizontal arms of.

page_text: To these flat arms o̟ o̟₂ are attached vertical bars P. P₂ reaching close to the
lower set of arms or to the bottom of the boiler.
The bars p, are so arranged, that no bar revolves round the shaft at the same
distance as any bar of another arm of the same set.
These bars carry blades at their lower extremity, made of two triangular pieces
of sheet-iron, which are riveted together with their longest sides perpendicular to
each other. These stirring-blades form tetrahedra open at the back and below,
which, acting like a steam-plough, mix up the mass.
Some of the stirring-blades are bent at the point to the left, others to the right,
Bo that one side is concave, the other convex, and one arm of each set has only
straight blades bent to the right, and the third bent to the left.
Besides these arms, the stirring-shaft has a long stirring-arm 82, which extends
at right-angles to the shaft and close to the wall of the cylinder down to the
bottom. This arm serves to remove any particles of the boiled mass or pulp from
the wall.
This stirring-apparatus sweeps over every point inside the cylinder, continually
agitating the mass, and thus thoroughly mixing up the particles of wood with the
fluid poured on them. The cock do serves to feed the inner cylinder direct with
steam; feeds the space between the cylinder and the casing.
The wide water gauge f, can be closed and the passages to the same cleansed
with steam.
Only steam can escape by the cock g₂, as the temperature in the boiler cannot
reach the boiling point of sulphuric acid.
The glucose-boiler and all the parts of the apparatus, and tubes coming into
contact with the acid or acid water, has a complete internal coating which is not
affected by sulphuric acid, for instance, lead, and all close vessels for the reception
of hot substances are provided with safety-valves, manometers and thermometers.
The glucose and wood-boilers are, moreover provided with steam injection taps ng
to rinse out the cylinders after they are emptied. Owing to the condensing
appliances used, a high pressure can exist in the extracting cylinder only. The
waste-wood in the glucose-boiler is mixed with dilute sulphuric acid and the
contents of the pan M, and this mixture which must always retain the same
consistency, is constantly stirred and boiled for several hours at about 130° C.
When the glucose-process is complete, the mass is thinned with steam and water
until it can be conveyed through the tube h₂ to the extracting cylinder H.
The solution of glucose flows from H through the tap ₁ into a vat Q.
The Glucose remaining in the residue is edulcorated by steam and water and
also flows into the vat Q to be further worked up.
The residue in the extracting cylinder consists of cellulose which has not been
decomposed.
Having now particularly described and ascertained the nature of my said
invention, and in what manner it is to be performed, I declare that what
I claim is
1-The employment of fusel-oil for the production of cellulose and glucose from
wood and other vegetable products by boiling with steam as a heating agent.
2-The employment of the following appliances shown in the drawing:
-The steam-apparatus C for driving off the oil and water.
b-The wood-boiler E.
-The extracting-cylinder H.
d-The clearing-pan T.
-The collecting-pan L.
f-The distilling-apparatus K, and
g-The glucose-boiler O.
in combination and in the order named, for the purpose of producing cellulose and
lus forward and atho zagotable products.

page_text: 3-The employment of a cylindrical boiler C provided with a steam-jacket,
stirring-apparatus and cock, for the purpose of extracting the oil and water from
wood and other vegetable products.
4 The production of inferior cellulose from small wood chips in extracting-
cylinders by means of high-pressure steam.