IMPROVEMENTS IN THE MANUFACTURE OF DINITRO-BENZOLE."
Year: 1881

page_text: LETTERS PATENT to James Alfred Kendall, of Dalston, in the County of
Middlesex, for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
DINITRO-BENZOLE."
PROVISIONAL SPECIFICATION left by the said James Alfred Kendall at
the Office of the Commissioners of Patents on the 9th February 1881.
話
JAMES ALFRED KENDALL, of Dalstou, in the County of Middlesex. IMPROVE-
MENTS IN THE MANUFACTURE OF DINITRO-BENZOLE.”
This Invention consists in the manufacture of dinitro-benzole, first, from the
gaseous compounds obtained in the process of the destructive distillation of coal
and other carbonaceous substances, and, secondly, from the said gaseous compounds
after they have been treated in the manner hereinafter referred to for obtaining
nitro-benzole; in both cases the desired object is effected by means of nitric and
sulphuric acids, as hereinafter described.
For the purpose of carrying out my Invention I select such coals or carbonaceous
substances as produce a gas rich in benzole, and I submit the said coals or
carbonaceous substances to the process of destructive distillation in the ordinary
way, and separate the tarry matters and other impurities from the gas produced
by deposition or any other well known process. I then pass the gas thus purified
through sulphuric acid, either cold or heated, with a view to further separating
impurities which would interfere to some extent with the economic working of the
process of obtaining the nitro-benzole and dinitro-benzole.
In order to obtain dinitro-benzole from the before mentioned gaseous compounds
when they have not previously been treated for obtaining nitro-benzole I proceed
as follows-The gas having been purified I pass it through suitablo vessels, into
one or more of which I put a mixture of nitric acid with sulphuric acid, having an
excess of sulphuric acid, the said mixture being composed of about 1 part of nitric
acid and about 5 parts of sulphuric acid. The effect of this mixture upon the gas
is to absorb the benzole suspended therein and convert it into dinitro-benzole,
which remains in the vessel or vessels employed.

page_text: Hitherto the manufacture of nitro-benzole from gas containing benzole by means
of nitric acid, or mixtures containing nitric acid, has been found to be too expensive
to be employed for producing nitro-benzole for commercial purposes, owing to the
fact that a quantity of the nitro-benzole formed passes away in the form of vapour
with the gas; however, I overcome such objection by obtaining, in the form of
dinitro-benzole, the nitro-benzole so carried away. To effect this object I pass the
gas as it escapes from the vessel or vessels employed for obtaining the nitro-benzole
through a vessel or vessels containing a quantity of the mixture, herein before
described, of nitric acid with sulphuric acid, by which means, the nitro-benzole
contained in the gas is converted into dinitro-benzole, and remains in the vessel
or vessels employed,
In obtaining dinitro-benzole, as hereinbefore described, I do not confine myself
to the exact proportions of the acids above mentioned, as it will be readily under-
stood that it will be necessary to vary such proportions with the different kinds of
gas used.
Instead of using nitric acid, mixtures of any salt of nitric acid with sulphuric
acid can be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Alfred Kendall in the Great Seal Patent Office on the
6th August 1881.
JAMES ALFRED KENDALL, of Dalston, in the County of Middlesex.
MENTS IN THE MANUFACTURE OF DINITRO-BENZOLE'
" IMPROVE-
My said Invention consists in the manufacture of dinitro-benzole, first, from the
gaseous compounds obtained in the process of the destructive distillation of coal
and other carbonaceous substances, and, secondly, from the said gaseous compounds
after they have been treated in the manner hereinafter referred to for obtaining
nitro-benzole; in both cases the desired object is effected by means of nitric and
sulphuric acids, as hereinafter described.
For the purpose of carrying out my Invention I select such coals or carbonaceous
substances as produce a gas rich in benzole, and I submit the said coals or
carbonaceous substances to the process of destructive distillation in the ordinary
way, and separate the tarry matters and other impurities from the gas produced by
deposition or any other well known process. I then pass the gas thus purified
through sulphuric acid, either cold or heated, with a view to further separating
impurities which would interfere to some extent with the economic working of the
process of obtaining the nitro-benzole and dinitro-benzole.
In order to obtain dinitro-benzole from the before mentioned gaseous compounds
when they have not been previously treated for obtaining nitro-benzole I proceed
as follows:-The gas having been purified I pass it through suitable vessels, into
one or more of which put a mixture of nitric acid with sulphuric acid, having an
excess of sulphuric acid, the said mixture being composed of about one part of
nitric acid and about five parts of sulphuric acid; the effect of this mixture upon
the gas is to absorb the benzole suspended therein and convert it into dinitro-
benzole, which remains in the vessel or vessels employed.
Hitherto the manufacture of nitro-benzole from gas containing benzole by means
of nitric acid, or mixtures containing nitric acid, has been found to be too expensive
to be employed for producing nitro-benzole for commercial purposes owing to the
fact that a quantity of the nitro-benzole formed passes away in the form of vapour
with the gas; however, I overcome such objection by obtaining in the form of
dinitro-benzole the nitro-benzole so carried away. To effect this object I pass the
gas as it escapes from the vessel or vessels employed for obtaining the nitro-benzole
through a vessel or vessels containing a quantity of the mixture herein before
described of nitric acid with sulphuric acid, by which means the nitro-benzole
contained in the gas is converted into dinitro- benzole, and remains in the vessel or
vessels employed.
In obtaining dinitro-benzole, as hereinbefore described, I do not confine myself
to the exact proportions of the acids above mentioned, as it will be readily under-
stood that it will be necessary to vary such proportions with the different kinds of
gas used.
Instead of using nitric acid, mixtures of any salt of nitric acid with sulphuric
acid can be employed.
Having thus described and ascertained the nature of my said Invention, and
the manner in which it is to be performed, I would observe in conclusion that
what I consider novel and original, and therefore claim as constituting the
Invention secured to me by the said hereinbefore in part recited Letters
Patent is,-
First. The manufacture of dinitro-benzole from gas containing benzole by means
of a mixture of nitric acid and sulphuric acid, the latter being in excess,
substantially as hereinbefore set forth and described.

page_text: And, Secondly. The manufacture, by means of a mixture of nitric acid and
sulphuric acid, the latter being in excess, of dinitro-benzole from the nitro-benzole
suspended in gas, substantially as hereinbefore set forth and described.
In witness whereof, I, the said James Alfred Kendall, have hereunto set
my hand and seal, this 2nd day of August, in the year of our Lord One 5
thousand eight hundred and eighty one.
JAMES ALFRED KENDAL