Improved Process and Apparatus for the Production of Best Hard Charcoal, together with the Simultaneous Recovery of Acetic Acid, Wood Spirit, Tar, Ammonia, Gas.
Year: 1889

page_text: Date of Application, 23rd Nov., 1889
Complete Specification Left, 13th Aug., 1890-Accepted, 15th Nov., 1890
PROVISIONAL SPECIFICATION.
Improved Process and Apparatus for the Production of Best
Hard Charcoal, together with the Simultaneous Recovery of
Acetic Acid, Wood Spirit, Tar, Ammonia, Gas.
I, LEOPOLD ZWILLINGER, of II. Volkertplatz 10, Vienna, in the Empire of
Austria, do hereby declare the nature of this invention to be as follows:-
This invention relates to the production of best hard charcoal from peat, wood,
brewers' grains or refuse, lignite, bones and other substances of organic origin,
together with the simultaneous recovery of ammonia, wood spirit, acetic acid,
tar and gas.
Hitherto it has been customary in order to bring about the carbonization of
organic materials in retorts, to simply heat them or to assist this heating by
the injection of steam or other gases as for instance water gas.
When the substances to be carbonized are simply heated in retorts the vola-
tile and condensable products evolved, deteriorate through the long contact with
the strongly heated and sometimes even glowing hot surfaces of the cylinder
and the often glowing hot charcoal producing material, and undergo a decom-
position whereby a deleterious diminution in the yield of distillation products is
caused. For these reasons attempts have been made to avoid the reduction
in the yield by the injection into the retorts, during the process of carbonization,
of steam, or gases containing carbonic oxide gas, such as for instance water
gas, and thus by the aid of this steam or gas to at once remove the volatile
products evolved from contact with the heated charcoal producing material
and the heated sides of the retort, that is to say, to remove them immediately
from the retort.
+
The processes in which merely steam is injected into the retorts have the dis-
advantage that steam alone, which is a gas easily condensed, is retained by
charcoal by reason of surface attraction, that is to say, it is hindered in its
movement and thus cannot perform in a sufficiently complete manner its object,
namely, to remove the volatile products evolved as quickly as possible from con-
tact with the heated retort and thus to preserve them from decomposition.
Another process in which, in place of steam, a gas is employed which is not
so easily condensed, contains carbonic oxide gas, and is free from oxygen, is
inconvenient from the fact that an apparatus for the production of such gases is
necessary.
In all these processes the introduction of air or free oxygen into the retorts
must be carefully avoided.
The object of the herein described invention is to remove the above named
drawbacks, and actually in contradistinction to these processes by the application
of atmospheric air which is employed to make the steam more readily movable
in the heated retorts containing the raw material.
Now if atmospheric air in its natural condition were introduced into the
carbonizing retorts, owing to the great quantity of oxygen contained in it, it
would cause, not only carbonization. but combustion of the material in them.
so by this invention atmospheric air is employed, which, by reason of its special
treatment with water, has its percentage of oxygen so diminished and at the
same time is so saturated with steam that only carbonization and not com-

page_text: bustion is brought about. The steam with which the air is saturated, that is
to say, which is absorbed by the air, is for this reason securely retained by the
air and casily carried through the material to be carbonized and can thus, by
its action on the material to be carbonized, assist the formation of acetic acid,
pyroligneous acid and ammonia, and especially with reference to the latter the
nitrogen present in the air employed has also a beneficial effect.
If atmospheric air be continually passed through water, firstly, the latter absorbs
from the air, oxygen and nitrogen in the proportionate quantities of 35 parts of
oxygen to 65 parts of nitrogen, and then also saturates the air with water vapour.
As atmospheric air consists of 79 per cent. parts of nitrogen and 21 per cent.
of oxygen, on its being constantly passed through water, it can no longer have
its former percentage composition, on the contrary, this air will now be consider-
ably poorer in oxygen and richer in nitrogen, 1 cubic metre of water of about
20 degrees Centigrade absorbs under the ordinary pressure 17.14 litres of air
in the proportion of 11.18 litres nitrogen to 5.96 litres of oxygen, whilst in
air continuously treated with water only 7 parts of oxygen to 93 parts of
nitrogen are contained. This air is further saturated with steam (1 cubic metre
of air saturated with steam contains for instance 251.3 grammes of water and
475.1 grammes or 0.48634 cubic metres of dry air) whereby the actual amount
of oxygen contained in the same is still further reduced so that by the injection
of such air in a heated condition in a closed receptacle filled with material for
carbonization, carbonization alone and never combustion takes place.
Accordingly numerous experiments made for the carbonizing wood, refuse,
brown coal (lignite) or peat, by means of superheated air saturated with steam
and rendered poor in oxygen through water treatment, have demonstrated with
the greatest success that in this manner, first, a better yield of acetic acid, wood
spirit and ammonia together with best hard charcoal is obtained, and then
also through the special utilization of atmospheric air the difficult and always
costly production of gases containing carbonic oxide gas is rendered unnecessary.
The apparatus suitable for carrying out this process is arranged somewhat in
the following manner:-
Atmospheric air is driven by the aid of an air compressor through a
pipe into a coil heated by a furnace, from whence the air heated to about
90 degrees Centigrade passes through another pipe into the lower part of a
mixing vessel filled to about a third with water. This mixing receptacle is
fitted with a rose inflow pipe, an exit pipe, air valve, manometer water gauge
glass and thermometer. The water flows in continuously in the form of spray
and passes away again in about the same quantity. Out of this mixing vessel
the air reduced in oxygen and charged with about 270 to 295 grammes of
steam per cubic metre, penetrates with a pressure of about 1 to 14 atmospheres
through a pipe to a superheater and thence through a perforated tube, into the
heated carbonization cylinders containing material to be carbonized, (namely
wood, peat, brown coal, (liguite), bones, or brewers' grains). The outlet from
the retort is connected by means of a tube with a condensing arrangement. In
the superheater, the air coming from the mixing receptacle is heated to 320
degrees to 400 degrees Centigrade, and simultaneously, the walls of the carboniz-
ing cylinders are sufficiently heated. The material in the cylinders is then
carbonized through the air thus superheated, saturated with steam and poor in
oxygen.
In order to maintain the temperature of the air saturated with steam at about
90 degrees Centigrade in the mixing receptacle, the water flowing through the
latter is regulated by an inflow cock situated on the rose and an exit cock on
the outflow pipe, preferably in such a way that about 17 litres of water pass
through per minute, and the level of the water in the receptacle always remains
even.
In this manner 800 to 1200 kilogrammes, which form a charge for a rotort,

page_text: can be carbonized in about 5 to 6 hours. Thereupon, the charcoal contained is
emptied into wrought iron cooling vessels, and the carbonizing cylinder is
again filled with fresh material. The condensable gases and vapours evolved
during the carbonization are condensed by means of a vigorous cooling by water,
the permanent gases on the other hand are utilized by burning them for light-
ing and heating purposes.
For every 800 kilogrammes of material to be carbonized about 40 to 42 cubic
metres of air saturated with steam are employed for 6 hours.
It may be further observed that the air, saturated with steam in the mixing
receptacle, becomes, in consequence of being afterwards superheated, again
capable of absorbing still more steam, which is furnished to it by the material
to be carbonized itself, so that, firstly, the air actually in a state of saturation
comes into action, and then also the steam developed in the carbonizing cylinder
is in a position relatively quickly to pass together with the other volatile pro-
duels out of contact with the heated material to be carbonized.
By this method there can be obtained, for instance, from 100 kilogrammes. of
dry beech wood. 50 to 55 kilogrammes of wood acid with 5.8 kilogrammes of
95 per cent. acetic acid (C, H, (,) and 2.2 kilogrammes of 93 per cent. pyro-
ligneous acid (wood spirit) (containing 72 per cent. CH, O methylalcohol and
28 per cent. (CH), CO acetone), whilst, by means of superheated steam the
wood acid obtained is diluted to 85 to 100 kilogrammes, and the yield only
reaches 5.2 kilogrammes 85 per cent. acetic acid and 1.8 kilogrammes 90 per cent.
wood spirit, including acetone. This enhanced yield. to which must be added a
greater yield of ammonia, may be easily explained through the combined action
of steam, in presence of the small quantity of oxygen quite insufficient for com-
bustion, on the carbonic acid containing material, in that thereby the amount
contained in the gases of CO and H increases, which unite, in statu nascendi,
with the vapour combinations arising from the carbonization (especially the
single value carbonic acid combinations) which assist the formation of acetic
acid, wood spirit whereto also the action of the abundant nitrogen in presence
of steam and organic matter assists, whereby an enhanced yield of ammonia is
induced.
Dated this 23rd day of November 1889.
WP. THOMPSON & BOULT,
Agents for the Applicant.
Improved Process and Apparatus for the Production of Best
Hard Charcoal, together with the Simultaneous Recovery of
Acetic Acid, Wood Spirit, Tar, Ammonia, Gas.
I. LEOPOLD ZWILLINGER, of Volkertplatz, Vienna, in the Empire of Austria,
Engineer, 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 relates to the production of best hard charcoal from peat, wood,
brewers' grains or refuse, lignite, bones and other substances of organic origin,
together with the simultaneous recovery of ammonia, wood spirit, acetic acid,
tar and gas.

page_text: Hitherto it has been customary in order to bring about the carbonisation of
organic materials in retorts, to simply heat them or to assist this heating by
the injection of steam or other gases as for instance water gas.
When the substances to be carbonised are simply heated in retorts the vola-
tile and condensable products evolved deteriorate through the long contact with
the strongly heated and sometimes even glowing hot surfaces of the cylinder
and the often glowing hot charcoal producing material, and undergo a decom-
position whereby a deleterious diminution in the yield of distillation products is
caused. For these reasons attempts have been made to avoid the reduction
in the yield by the injection into the retorts, during the process of carbonisation,
of steam, or gases containing carbonic oxide gas, such for instance as water
gas, and thus by the aid of this steam or gas to at once remove the volatile
products evolved from contact with the heated charcoal producing material
and the heated sides of the retort, that is to say, to remove them immediately
from the retort.
The processes in which merely steam is injected into the retorts have the dis-
advantage that steam alone, which is a gas easily condensed, is retained by
charcoal by reason of surface attraction, that is to say, it is hindered in its
movement and thus cannot perform in a sufficiently complete manner its object,
namely, to remove the volatile products evolved as quickly as possible from con-
tact with the heated retort and thus to preserve them from decomposition.
Another process in which, in place of steam, a gas is employed which is not
so easily condensed, contains carbonic oxide gas, and is free from oxygen, is
inconvenient from the fact that an apparatus for the production of such gases is
necessary.
In all these processes the introduction of air or free oxygen into the retorts
has been carefully avoided.
The object of the herein described invention is, in contradistinction to these
processes, to remove the above named drawbacks by the application of atmos-
pheric air which is employed to make the steam more readily movable in the
heated retorts containing the raw material.
Now if atmospheric air in its natural condition were introduced into the
carbonizing retorts, it would cause, owing to the great quantity of oxygen con-
tained in it, not carbonization, but combustion of the material in them.
so by this invention atmospheric air is employed, which, by reason of its special
treatment with water, has its percentage of oxygen so diminished and at the
same time is so saturated with steam that only carbonisation and not com-
bustion is brought about. The steam with which the air is saturated, that is
to say, which is absorbed by the air, is for this reason securely retained by the
air and easily carried through the material to be carbonised and can thus, by
its action on the material to be carbonized, assist the formation of acetic acid,
pyroligneous acid and ammonia, and especially with reference to the latter the
nitrogen present in the air employed has also a beneficial effect.
If atmospheric air be continually passed through water, firstly, the latter absorbs
from the air, oxygen and nitrogen in the proportionate quantities of 35 parts of
oxygen to 65 parts of nitrogen, and then also saturates the air with water vapour.
As the atmospheric air consists of 79 per cent. of nitrogen and 21 per cent.
of oxygen, it can, on its being constantly passed through water, no longer have
its former percentage composition, on the contrary, this air will be now consider-
ably poorer in oxygen and richer in nitrogen, I cubic metre of water at about
20 degrees Centigrade absorbs under the ordinary pressure 17.14 litres of air
in the proportion of 11.18 litres of nitrogen. to 5.96 litres of oxygen, whilst in
air continuously treated with water only 7 parts of oxygen to 93 parts of
nitrogen are contained. This air is further saturated with steam (1 cubic metre
of air saturated with steam contains for instance 251.3 grammes of water and
475.1 grammes or 0.48634 cubic metres of dry air) whereby the actual amount
of oxygen contained in the same is still further reduced so that by the injection

page_text: of such air in a heated condition in a closed receptacle filled with material for
carbonisation, carbonisation alone and never combustion takes place.
Accordingly numerous experiments made for carbonising wood, refuse,
brown coal (lignite) or peat, by means of superheated air saturated with steam
and rendered poor in oxygen through water treatment, have demonstrated with
the greatest success that in this manner, first, a better yield of acetic acid, wood
spirit and ammonia together with best hard charcoal is obtained, and then
also through the special utilisation of atmospheric air the difficult and always
costly production of gases containing carbonic oxide gas is rendered unnecessary.
In order to do this, the process forming the subject of this invention is carried
out somewhat as follows; for which purpose the apparatus represented in the
annexed drawing, in which
Figure 1 in a longitudinal and Figure 2 in a horizontal section, is preferably
employed.
Atmospheric air is driven by the aid of an air compressor C through a pipe K
into a coil S heated by a furnace F, from whence the air heated to about
90 degrees Centigrade passes through another pipe Winto the lower part of a
mixing vessel M filled to about a third with water. This mixing receptacle is
fitted with a rose inflow pipe A, an exit pipe B, air valve L, manometer E, water
gauge glass H, and thermometer T. The water flows in continuously in the form
of spray and passes away again in about the same quantity. Out of this mixing
vessel the air reduced in oxygen and charged with about 270 to 295 grammes of
steam per cubic metre, penetrates with a pressure of about 1 to 1 atmospheres
through a pipe P to a superheater and thence through a perforated tube V
into the heated carbonisation cylinders Z containing material to be carbonised,
(namely, wood, peat, brown coal (lignite) bones, or brewers' grains). The outlet
from the retort is connected by means of a tube with a condensing arrangement.
In the superheater U. the air coming from the mixing receptacle M is heated to
320 to 400 degrees Centigrade, and simultaneously, the walls of the carbonising
cylinders are sufficiently heated. The material in the cylinders is then carbonised
by means of the air thus superheated, saturated with steam and poor in oxygen.
In order to maintain the temperature of the air saturated with steam at about
90 degrees Centigrade in the mixing receptacle, the water flowing through the
latter is regulated by an inflow cock situated on the rose and an exit cock on
the outflow pipe preferably in such a way that about 170 litres of water pass
through per minute, and the level of the water in the receptacle always remains
the same.
In this manner 800 to 1200 kilogrammes, which form a charge for a retort.
can be carbonised in about 5 to 6 hours. Thereupon, the charcoal contained is
emptied into wrought iron cooling vessels and the carbonising cylinder is
again filled with fresh material. The condensable gases and vapours evolved
during the carbonisation are condensed by means of a vigorous cooling by water,
the permanent gases on the other hand are utilised by burning them for light-
ing and heating purposes.
For every 800 kilogrammes of material to be carbonised about 40 to 42 cubic
metres of air saturated with steam are employed for 6 hours.
It may be further observed that the air, saturated with steam in the mixing
receptacle, becomes, in consequence of being afterwards superheated, again
capable of absorbing still more steam, which is furnished to it by the material
to be carbonised itself, so that, firstly, the air actually in a state of saturation
comes into action, and then also the steam developed in the carbonising cylinder,
is in a position to pass comparatively quickly, together with the other volatile
products, out of contact with the heated material to be carbonised.
By this method there can be obtained, for instance, from 100 kilogrammes of
dry beech wood, 50 to 55 kilogrammes of wood acid with 5.8 kilogrammes of
95 per cent. acetic acid (C, H, O₂) and 2.2 kilogrammes of 93 per cent. pyro-
ligneous spirit (wood spirit) containing 72 per cent. CH. O methylalcohol and

page_text: 28 per cent. (CH)2 CO acetone, whilst, by means of superheated steam, the
wood acid obtained is diluted to 85 to 100 kilogrammes, and the yield only
reaches 5.2 kilogrammes 85 per cent: acetic acid and. 1.8 kilogrammes 90 per cent.
wood spirit, including acetone.
This enhanced yield, to which must be added a greater yield of ammonia,
may be easily explained through the combined action of steam, in presence of
the small quantity of oxygen which is quite insufficient for combustion, on the
carbonic acid containing material, whilst by this action the amount contained in
the gases, of CO and H increases, which latter unite, in statu nascendi, with the
vapour combinations arising from the carbonisation (especially the single value
carbonic acid combinations) and assist the formation of acetic acid, wood spirit,
whereto also the action of the. abundant nitrogen in presence of steam and
organic matter assists, and thus an enhanced yield of ammonia is induced.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. A process, for the production of best hard charcoal, together with the
simultaneous recovery and increased yield of products such as acetic acid, wood
spirit, tar, ammonia, gas resulting from the carbonisation of carbon-containing
materials of all kinds such as peat, wood, suitable waste vegetable products,
lignite, bones, etcetera; which consists in making atmospheric air (preferably in
a heated condition) poorer in oxygen and saturated with steam by passing it
through water, then superheating it (preferably up to about 400 degrees Centi-
grade) and finally forcing it under pressure into the material to be carbonised
_contained in retorts hermetically closed and heated from outside.
2. The apparatus for carrying-out-the process-described in Claim 1, consisting
essentially of an air compressor C, a series of pipes K S W. passing from this
compressor through a superheating furnace to a mixing vessel M containing
water and fitted with a water supply and discharge pipe, a superheater U con-
nected with the same for the air emerging from the mixing receptacle, which
superheater is connected with retorts (capable of being heated from the outside
and hermetically closed) by means of a pipe and a perforated tube situated in
the interior of the retorts, substantially as described.
Dated this 12th day of August 1890.
WM. P. THOMPSON & BOULT,
Of 6, Lord Street, Liverpool, Agents for the Applicant.