Improvements in and relating to the Manufacture of Acetic Acid and its By-products.
Year: 1888

page_text: Improvements in and relating to the Manufacture of Acetic Acid
and its By-products.
I, RUDOLF WEISS, Doctor of Philosophy, residing at Zossen near Berlin, Empire
of Germany do hereby declare the nature of invention for IMPROVEMENTS IN AND
RELATING TO THE MANUFACTURE OF ACETIC ACID AND ITS BY-PRODUCTS to be as
follows:
This invention relates to the treatment of any organic matters (f.e. wood, peat,
brown-coal etc.) in order to obtain acids (such as acetic acid), methylic alcohol, tar-
products, coal or coke i.e. to obtain such substances as the are formed during the
carbonisation of organic matters.
Hitherto this process of carbonisation has been performed either simply by heating
the organic matters in a closed chamber having a suitable outlet-device for leading
away the volatile products, or by heating them in a retort and introducing superheated
steam.
By the first method of carbonisation a too small quantity of volatile condensable
products are obtained because the latter will be often partly decomposed by coming
long time in contact with the heated and often glowing carbonaceous substance. The
result of the method consisting in heating the matters to be carbonised by means of
superheated steam is considerably better; but steam acting upon heated carbon
produces a loss of solid carbon and also the steam being a condensable gas will be
retained by the attractive power of the surface of the carbon and therefore the move-.
ment of the steam will be decreased. This circumstance has the result that the acetic
acid will remain any time in contact with the carbon and therefore the acid will be
at least partly decomposed by means of the high temperature in the retort and there-
fore a loss of acetic acid will be produced. Also it cannot be avoided that with the
steam air and atmospheric oxygen-gas passes into the retort and the latter gas
decomposing the evaporated products and burning the carbon produces losses.
Moreover the known methods for superheating steam offer considerable disadvantages
and difficulties which have already led to several proposals for new processes or
apparatus in order to render the superheating-devices more durable and efficacious.

page_text: According to the present invention these disadvantages will be omitted and also
a greater quantity of solid and volatile products, such as carbon and acetic acid, be
obtained.
Because in order to prevent a decomposition of the acetic acid and of the volatile
by-products of the same by the hot coal or carbon it appears necessary to lead away
from the coal or carbon as quickly as possible the products formed and evaporated
by heating the above mentioned organic matters, of which products the acetic-acid
may serve as example in this description, a gas must be used which is not so
condensable and will not be attracted by the surface of the coal or carbon so easily as
the steam. For preventing losses this gas must not be decomposable by the coal or
carbon. Watergas (i.e. a mixture of hydrogen and oxide of carbon) being
product of decomposition of the steam and carbon appear to be a gas of the afore-
said qualities in as much as acetic acid and oxide of carbon will be developed
simultaneously by heating wood or other organic matters.
a
I have found by experiments that first of all the absence from free oxygen and
the presence of oxide of carbon are adapted to increase essentially the production of
acetic acid, of previous volatile condensable products and of carbon.
For all these reasons I have invented the following process consisting in heating
organic matters in a retort by means of a gas free from oxygen and containing oxide
of carbon
the condensing
A rert having an outlet-pipe or pipes conducting o
devices and having also an inlet pipe or pipes will be charged or filled with the organic
material, such as wood, peat or the like, in not too great pieces. Now this retort
will be weakly heated and then hot water-gas or regenerator gas, the latter consisting
essentially of oxide of carbon and nitrogen, or another gas free from oxygen and
containing oxide of carbon will be led into the retort. It is preferable to cool the
watergas or regenerator gas or the other gas obtained in a very hot state in such a
degree as to receive a temperature not higher than 570° to 750° Fahr. These gases
may be cooled by heating any evaporating- or distilling-devices with these hot gases.
Then the retort or the interior of the retort will be preserved on the temperature of
about 570° Fahr. till the developement of acetic acid ceases. At this moment the
temperature may be increased to about 750° Fahr. till the developement of volatile
products ceases. Now the process is finished and the retort containing carbon may
be discharged and then once more refilled. The volatile products may be condensed
and the incondensable products be used for any purpose and in any manner, f.e. for
heating purposes by burning these products.
Dated this 3rd dow of Tul., 1980

page_text: COMFIELD
Improvements in and relating to the Manufacture of Acetic Acid
and its By-products.
I, RUDOLF WEISS, Doctor of Philosophy, residing at Zossen, Empire of Germany
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and acertained in and by the following
statement:-
This invention relates to the treatment of wood, peat, brown-coal, pit-coal or other
organic substances in order to obtain acids (preferably acetic acid), methylic alcohol,
tar-products, carbon or coke i.e. to obtain such products as they are formed during
the carbonisation of organic substances.
Hitherto this process of carbonisation has been performed either simply by heating
the organic substances in a closed chamber having a suitable outlet-device for leading
away the volatile products, or by heating them in a retort and introducing super-
heated steam. By the first method of carbonisation a too small quantity of volatile
condensable products are obtained as the latter will be often partly decomposed by
coming long time in contact with the heated and often glowing carbonaceous
substance. The result of the method consisting in heating the organic substances to
be carbonised by means of superheated steam is considerably better; but steam acting
upon heated carbon produces a loss of solid carbon and also the steam being a
condensable gas will be retained by the attractive power of the surface of the carbon
and therefore the movement of the steam will be decreased. This circumstance has
the result that the acetic acid will remain any time in contact with the carbon and
therefore the acid will be at least partly decomposed by means of the high
temperature in the retort and therefore a loss of acetic acid will be produced. Also
it cannot be avoided that with the steam air and atmospheric oxygen-gas passes into
the retort and the latter gas decomposing the evaporated products and burning the
carbon produces losses. Moreover the known methods for superheating steam offer
considerable disadvantages and difficulties which have already led to several proposals
for new processes or apparatus. in order to render the superheating-devices more
durable and efficacious.
According to the present invention these disadvantages will be omitted and also a
greater quantity of solid and volatile products, such as carbon and acetic acid be
obtained.
Because in order to prevent a decomposition of the acetic acid and of the volatile
by-products of the same by the hot coal or carbon it appears necessary to lead away
from the coal or carbon as quickly as possible the products formed and evaporated by
heating the above mentioned organic substances, of which products the acetic acid
may serve as example in this description, a gas must be used, which is not so
condensable and will not be attracted by the surface of the coal or carbon so easily as
the steam. For preventing losses this gas must not be decomposable by the coal or

page_text: carbon. Water gas (i.e. a mixture of hydrogen and oxide of carbon) being a product
of decomposition of the steam and carbon appear to be a gas of the aforesaid
qualities inasmuch as acetic acid and oxide of carbon will be developed simultaneously
by heating wood or other organic substances.
I have found by experiments that first of all the absence from free oxygen and the
presence of oxide of carbon are adapted to increase essentially the production of
acetic acid, of precious volatile condensable products and of carbon.
For all these reasons I have invented the following process, consisting in heating
organic substances in a retort (or retorts) by introducing in this retort (or these
retorts) a gas practically free from oxygen-gas and containing oxide of carbon. For
the hereindescribed process water-gas or regenerator-gas are preferably employed,
but any gas practically free from oxygen-gas and containing oxide of carbon may
be used in like manner.
A retort (or retorts) having an outlet-device (or-devices) conducting or leading to
the condensing-devices and having also an inlet-device (or-devices) will be charged or
filled with the organic material (such as wood, peat, brown-coal or the like) in not
too great pieces. Now, if desired, this retort (or these retorts) will be weakly heated
from the outside and then hot water-gas or regenerator-gas, the latter consisting
essentially of oxide of carbon and nitrogen, will be led into the retort (or retorts).
It is preferable to cool the water-gas or regenerator-gas obtained in a very hot
state in such a degree as to receive a temperature not, higher than about 570°
to 750° Fahr. These gases may be cooled by heating any evaporating or distilling-
devices by means of these hot gases. Then the retort (or retorts) or the interior of
the retort (or retorts) will be preserved on the temperature of about 570° Fahr.
till the developement of acetic acid ceases. At this moment the temperature may be
increased to about 750° Fahr. till the developement of volatile products ceases, after
which the retort (or retorts) may be heated to a higher degree if the structure of the
obtained carbon does not appear to be sufficiently dense or compact. Now the
process is finished and the retort (or retorts) containing carbon may be discharged
and then once more refilled. The volatile products may be condensed in any
suitable or usual manner, and the incondensable products be used for any purpose
and in any manner, i.e. for heating purposes by burning these products.
Having now particularly described and ascertained the nature of my said Inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:
The hereindescribed process for producing acetic acid, carbon and volatile products
as they are formed during the carbonisation of wood, peat, brown-coal, pit-coal or
other organic substances, which process consists in treating such substances in a retort
(or retorts) by introducing hot oxide of carbon, water-gas, regenerator-gas or other
gas (or gases) containing oxide of carbon and being practically free from oxygen-gas
with or without heating said retort (or retorts) from outside.
Dated this 30th day of March 1980