An Improved Process for Obtaining Benzol and similar Aromatic Hydrocarbons.
Year: 1896

page_text: Date of Application, 25th Nev., 1890
Complete Specification Left, 14th Aug., 1897-Accepted, 25th Sept., 1897
Complete Specification Left, 14th Aug., 1897-Accepted, 25th Sept., 1897
PROVISIONAL SPECIFICATION.
An Improved Process for Obtaining Benzol and similar Aromatic
Hydrocarbons.
I, GUSTAV SCHULTZ, of 3, Giselastrasse, Munich in the Empire of Germany, Doctor
of Philosophy, Professor in the Technical High School at Munich, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a process for industrially obtaining benzol and the like
aromatic hydrocarbons, which are so important and valuable for the manufacture of
colours, in considerably larger quantities than was hitherto possible in the ordinary
way of manufacture of lighting-gas and coke.
In the method of treatment hitherto employed, there were obtained from the coal
tar produced in the manufacture of lighting-gas and coke, only comparatively small
quantities of these hydrocarbons (benzol, toluol, xylol, naphthalene and anthracene)
contained in said tar and valuable for the manufacture of colours, but large quantities
of pitch (about 50% of the total tar) and oily residues regarded as less valuable
(about 40%).
By the present invention the coal tar is treated in a more successful manner,
yielding larger returns of the above mentioned valuable hydrocarbons than has hitherto
been obtained.
Experiments carried out with this object have shown that, in addition to the
obtaining of the valuable hydrocarbons contained in the coal tar, it is also possible
to treat industrially the oily residues obtained with it, so that they are converted in
the simplest manner into said valuable hydrocarbons, for which the apparatuses
already existing, for instance for the manufacture of lighting-gas or coke, may be
employed.
This treatment takes place according to the present invention by the above mentioned
oily residues of coal tar, from which the benzol and like valuable aromatic hydro-
carbons contained have been removed, being decomposed in suitable apparatuses by
strong heat, and the distillate resulting therefrom, which then again contains
valuable aroinatic hydrocarbons, being condensed.
It has already been shown by the researches of Berthelot, Graebe, G. Schultz and
others, that aromatic hydrocarbons, to which the above mentioned oily residues are
closely related, are decomposed in a vaporised condition, by strong heat, for instance
by conducting the vapour through incandescent pipes, in such a way that there
result on the one hand simpler and on the other hand more complicated compounds
than the original material. It has not, however, been proposed hitherto to utilize
this fact industrially, because no rational industrially applicable process for doing this
was known, and it was also not known that it is possible to utilize this circumstance
in an industrial manner so that the said oily residues are converted into aromatic
compounds, more particularly valuable for the manufacture of colours. This is
attained by the present invention, corresponding to what has been herein before stated
in the following manner
The oily residues remaining from the treatment of coal tar, after the removal of the
benzol, toluol, xylol, naphthalene and anthracene contained therein, are conveyed into

page_text: the original material. It has not, however, been proposed hitherto to utilize this
fact industrially, because no practical industrially applicable process for doing this
was known, and it was also not known that it is possible to utilize this circumstance
in an industrial manner so that the said oily residues are converted into aromatic
compounds, more particularly valuable for the manufacture of colours. This is
attained by the present invention, corresponding to what has been hereinbefore stated,
in the following manner,
The oily residues remaining from the treatment of coal tar, after the removal of
the benzol, toluol, xylol, naphthalene and anthracene contained therein are conveyed
into glowing hot retorts of lighting-gas works, or into glowing hot coke ovens, which
are preferably provided with a suction device or exhauster. This may take place
preferably by the oily residues being caused to flow into the said glowing retorts or
coke ovens in a fine jet or in the form of vapour; or coke or coal saturated
therewith may be inserted. The resultant vapours, which, in consequence of the
decomposition thereby resulting, now contain valuable aromatic hydrocarbons such
as benzol, toluol, xylol, naphthalene and anthracene, are removed from the heating
chambers by means of pipes or suitable draw off devices, and may be simply
conveyed to the existing condensers, after which these valuable hydrocarbons are
removed from the condensate in the ordinary manner.
In this manner there is obtained, in the ordinary working, a considerably larger
quantity than hitherto of valuable aromatic hydrocarbons.
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 :-
A process for obtaining an increased yield of benzol and the like valuable aromatic
hydrocarbons in the manufacture of lighting gas and coke, such process consisting
in conveying into the glowing retorts or glowing coke ovens the oily residues
resulting from the extraction of the valuable aromatic hydrocarbons contained in
the coal tar obtained in the course of the above named manufacture, after the
said oily residues have been freed from the valuable aromatic hydrocarbons, with
the object of decomposing said residues and reproducing such valuable aromatic
hydrocarbons, the distillate obtained thereby being afterwards condensed,
substantially as hereinbefore set forth.
Dated this 13th day of August 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.