IMPROVEMENTS IN THE PRODUCTION OF ANTHRACENE
Year: 1878

page_text: LETTERS PATENT to Josiah Hardman; of Milton, in the County of Stafford,
Manufacturing Chemist, and George Wischin, of the saine Place, Chemist, for
the Invention of " IMPROVEMENTS IN THE PRODUCTION OF ANTHRACENE."
Sealed the 6th May 1879, and dated the 7th November 1878.
PROVISIONAL SPECIFICATION left by the said Josiah Hardman and George
Wischin at the Office of the Commissioners of Patents on the 7th November
1878.
JOSIAH HARDMAN, of Milton, in the County of Stafford, Manufacturing Chemist,
and GEORGE WISCHIN, of the same Place, Chemist. "IMPROVEMENTS IN THE
PRODUCTION OF ANTHRACENE."
Our Invention consists in causing the vapours of certain high boiling hydro-carbons
obtained in the latter stages of coal tar distillation and boiling above 220° centigrade
to pass over a layer of carbon, preferably coke, charcoal, animal charcoal, or any
porous material impregnated with carbon and heated to a sufficiently high tempera-
ture, say a dull red heat.
Anthracene is thus generated out of a small part of those
hydro carbons under the influence of heat and probably of the surface action of
the carbon.
In carrying out our Invention we charge gas retorts, brick ovens, tubes, or other
such suitable apparatus with broken up coke or other such material as aforesaid, and
heat the vessels with their contents to a sufficiently high temperature, preferably to a
dull red heat, to cause the vapours of the said hydro-carbons to traverse the heated
coke or other such substance. The hydro-carbons may be conveyed to the heated
vessels in a gradual stream or may be vapourised first, and such vapours then con-
veyed thereto by any suitable means. The vapours after they have traversed the
heated materials are condensed and the anthracene extracted by any well known
means.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Josiah Hardman and George Wischin in the Great Seal Patent Office
on the 7th May 1879.
.
JOSIAH HARDMAN, of Milton, in the County of Stafford, Manufacturing Chemist,
and GEORGE WISCHIN, of the same Place, Chemist. "IMPROVEMENTS IN THE
PRODUCTION OF ANTHRACENE."
Our Invention consists in causing the vapours of certain high boiling hydro-
carbons obtained in the latter stages of coal tar distillation and boiling above 220°
centigrade to pass over a layer of carbon, preferably coke, charcoal, animal charcoal,
or any porous material impregnated with carbon and heated to a sufficiently high
temperature, say a dull red heat. A small fraction by weight of the said hydro-
carbon is so converted into anthracene under the influence of heat, and probably the
surface action of the carbon. The hydro-carbons best suited to our purpose are the
mother liquors from the manufacture of anthracene and known by the name of
anthracene oil. In carrying out our Invention we use ordinary gas retorts or ovens
heated to a dull red heat in furnaces similar to those used in the gas manufacture,
such retorts or ovens having been densely packed with broken up coke, charcoal,
or other such substance as aforesaid. The necessary heat having been imparted the
anthracene oil is admitted to the retort in a slow continuous and regular stream at
The
one end by means of any suitable apparatus employed for analogous purposes.
.first result is the vapourization of the anthracene oil, which by being further sub-
jected to the high temperature and passing over the coke or other such substance
becomes partially converted into anthracene. The vapours thus treated pass from
the other end of the retort or oven through a suitable pipe and are condensed in
the usual manner, after which the anthracene contained in the condensed product is
extracted by the well known process of distillation, cooling down, crystillization,
pressing, and washing with solvents. Instead of the process being conducted pre-
cisely as above described the oil might first be vapourized in a separate vessel and
such vapour be conveyed to the retort or oven and treated as above described.
Having thus described and ascertained the nature of my said Invention and the
manner in which the same is to be performed, I desire it to be understood that we
claim as secured to us under the above in part recited Letters Patent, the treatment
of hydro-carbons above mentioned, by causing them or their vapours to pass over
heated coke, or other such carbonaceous materials as aforesaid for the purpose of
producing anthracene.
'
In witness whereof, I, the said Josiah Hardman, have hereunto set my hand
and seal, this Sixth day of May, in the year of our Lord One thousand eight
ina