IMPROVEMENTS IN THE DISTILLATION OF ANTHRACENE
Year: 1880

page_text: LETTERS PATENT to Cyrus M. Warren, of Brookline, in the County of Norfolk
and State of Massachusetts, one of the United States of America, for an
PROVISIONAL SPECIFICATION left by the said Cyrus M. Warren at the
Office of the Commissioners of Patents on the 31st May 1880.
CYRUS M. WARREN, of Brookline, in the County of Norfolk and State of
Massachusetts, one of the United States of America. "IMPROVEMENTS IN THE
DISTILLATION OF ANTHRACENE."
The object of this Invention is to obtain an increased percentage or yield of
anthracene from coal-tar or coal-tar pitch, and at the same time preserve the
residual or secondary product of the operation in a fusible and soluble condition
suitable for the various uses for which the ordinary hard coal-tar residuum, or so
called pitch, is now employed and for other purposes.
The Invention consists in the process of distilling in any suitable proportions a
mixture of coal-tar-pitch (the anthracene from which may or may not have been
partially removed in the usual manner) and petroleum residuum, wax-tailings, or
other equivalent solvent and fixed material [such as may be produced at a suitable
high temperature, either as a residuum or distilled product, at or near the end of
the distillation of natural bitumens, bituminous coals, bituminous shales, bituminous
schists, or other substances yielding hydrocarbon oils by distillation, or at or near
the end of the re-distillation of such oils or the residuums of the same at a high
temperature], by which process under the influence of an elevated temperature
the less stable coal-tar oils containing the anthracene are for the most part or
entirely displaced and distil over, while the more fixed hydrocarbons of the
petroleum residuum or other equivalent material are substituted and retained in
the retort-residue to an extent sufficient to preserve the same while hot in a fluid
and homogenious condition, which latter remains on cooling.
Petroleum residuum is the tarry residue from the ordinary distillation of
petroleum.
"Wax tailings" is the last or about the last distillate collected from petroleum
residuum when the distillation is carried to coke or dryness. As obtained from
different manufacturers its consistency is variable from fluid to that of stiff wax
or pitch. Being usually a mixture or solution of the latter in the heavy oils.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Cyrus M. Warren in the Great Seal Patent Office on the 30th
November 1880.
CYRUS M. WARREN, of Brookline, in the County of Norfolk and State of
Massachusetts, one of the United States of America. "IMPROVEMENTS IN
OBTAINING ANTHRACINE."
My Invention relates to a new or improved process for the production or
manufacture of crude anthracene from coal-tar, and for producing at the same time
as a secondary product an improved material to serve as an ingredient of
asphaltic paving and roofing cement or mastic.
The Invention consists, first, in the process of distilling in any suitable pro-
portions a mixture either of coal-tar or coal-tar pitch and petroleum residuum,
otherwise called petroleum tar, wax-tailings, or other equivalent solvent and fixed
material, such as may be produced at a suitably high temperature, either as a
residuum or distilled product, at or near the end of the distillation of natural
bitumens, bituminous coals, bituminous shales, bituminous schists, or other
substances yielding hydrocarbon oils by distillation, or at or near the end of
the re-distillation of such oils or the residuums of the same at a high temperature.
The Invention also consists in a paving or roofing material or compound formed
as a residual product by the process above described.
In carrying out my Invention I prefer to operate on forty five (45) barrels of
coal-tar (or an equivalent quantity of coal-tar pitch), and distil the same in the
ordinary manner to take off the naphtha, creosote, or "dead oil," and so much of
the anthracene oil as is practicable or customary in working by the common
method, i.c., so much as can be removed and preserve the coal tar residuum or pitch
in a fluid condition, and then inject about seven and one half (7) barrels of hot
petroleum residuum (which should be thoroughly agitated and dissolved with the
coal tar residuum in the still), and then continue the distillation, with or without
the introduction of steam, as may be preferred to take off about the same quantity
as before of anthracene oil. It is preferable to collect this portion of the anthracene
oil by itself, since it comes over more or less mixed with paraffine oils or products
of decomposition of petroleum residuum, necessitating special treatment for the
removal of these impurities from the anthracene.
The compound residuum in the still if not required for immediate use may be
drawn out into an open vat or tubs and cooled, to be remelted and mixed with
other ingredients as may be required for any purpose.
In some of its properties and for certain purposes this compound residuum is
superior to the ordinary residuum from the distillation of coal-tar by itself for
anthracene, since the natural oils of the latter residuum are to a great extent (and
by some petroleum products may be completely) eliminated by this process, and
replaced by the more fixed oils of the petroleum residuum. Petroleum residuum
is the tarry residue from the ordinary distillation of petroleum. Wax-tailings are
the last or about the last distillate collected from petroleum residuum when the
distillation of this material is carried to dryness. As obtained from different
manufacturers its consistency is variable, from fluid to that of stiff wax or pitch,
being usually a mixture or solution of the latter in the heavy oils.
The filtered or partially pressed anthracene from the extra product of anthracene
oil above mentioned contains a considerable quantity of solid paraffine, which may
be mostly extracted by means of petroleum oil of medium density or other suitable
solvent, and the purification finally completed by hydraulic pressure by the aid of
gradually increasing heat. This part of the purification, which should be complete,
is easily effected, since paraffine melting at a lower temperature will for the most

page_text: part be pressed out before the other and natural solid impurities of the anthracene,
which latter impurities melting in their turn as the temperature and pressure are
increased serve to expel the last trace of paraffine.
Having thus described my Invention and the best means with which I am
acquainted for carrying the same into effect, I would state in conclusion that I do
not confine myself rigidly to the precise details above given, as these may be
varied to some extent without deviating from the principal features of the
Invention, but what I consider to be new and therefore claim as my Inven-
tion is,―
1. The process of obtaining anthracene by the distillation of a mixture of coal-tar
or coal-tar pitch and petroleum residuum or other equivalent material, substantially
set forth.
2. As a new manufacture the compound bituminous residuum obtained by sub-
jecting a mixture of coal tar or coal tar pitch and petroleum residuum or other
equivalent material to a distilling process, substantially in the manner specified or
by any other method which will produce a like result.
In witness whereof, I, the said Cyrus M. Warren, have hereunto set my
hand and seal, this Twenty seventh day of November, in the year of our
Lord One thousand eight hundred and eighty.
CYRUS M. WARREN. (L.S.)