AN IMPROVED METHOD OF OBTAINING BENZOLE AND ITS HOMOLOGOUS SUBSTANCES FROM COAL GAS
Year: 1869

page_text: ETTERS PATENT to William Robert Lake, of the "Internationa!
Patent Office," No. 'S, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Consulting Engineer, for the Invention
of "AN IMPROVED METHOD OF OBTAINING BENZOLE AND ITS HOMOLOGOUS
SUBSTANCES FROM COAL GAS."-A communication from abroad by Henry
Caro, August Clemm, Charles Clemm, and Frederic Engelhorn, all
of Mannheim, Baden, Germany.
ealed the 13th August 1869, and dated the 17th February 1869.
PROVISIONAL SPECIFICATION
left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 17th February 1869.
35
I WILLIAM ROBERT LAKE, of the "International Patent Office,'
No. 8, Southampton Buildings, Chancery Lane, in the County of Mid-
dlesex, Consulting Engineer; do hereby declare the nature of the said
Invention for "AN IMPROVED METHOD OF OBTAINING BENZOLE AND
ΣΤΟ

page_text: HOMOLOGOUS SUBSTANCES FROM COAL GAS," a communication, to be as
follows:-
The gaseous products resulting from the destructive distillation of
coal, commonly called "coal gas," contain a variable amount of benzole
and its homologous substances, which, as is well known, may partly be
separated therefrom by submitting the gas to cold or pressure, or to a
treatment with chemical re-agents, such as nitric and sulphuric acids,
chlorine, and bromine.
My improved method of obtaining benzole and its homologous sub-
stances from coal gas consist in bringing coal gas in contact with such
substances as will act as solvents for the benzole and its homologous
substances contained therein without, at the same time, causing them
to undergo any chemical change, and, although it has been found that
all known solvents of benzole effect this purpose, I prefer to place the
coal gas in contact with certain. hydrocarbons, such as petroleum,
schist, and mineral oils, and the higher boiling varieties of coal tar or
naptha.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 16th August 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Consulting
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of February, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Robert Lake, Her
special licence that I, the said William Robert Lake, my executors,
administrators, and assigns, or such others as I, the said William
Robert Lake, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
of "AN IMPROVED METHOD OF OBTAINING BENZOLE AND ITS HOMOLOGOUS SUB-
STANCES FROM COAL GAS," upon the condition (amongst others) that I;
the said William Robert Lake, my executors or administrators, by an
instrument in writing under my, or their, or one of their. hands and
seals, should.particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE,. that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement:
"The gaseous products resulting from the destructive distillation of
cual, commonly called "coal-gas," contain a variable amount of benzole
and its homologues, which, as is well known, may partly be separated
therefrom by.submitting the gas to cold or pressure, or to a treatment
with chemical ré-agents, such as nitric and sulphuric acids, chlorine, .
and bromine.
The said improved method of obtaining benzole and its homologues
from coal gas consists in placing coal gas in contact with such sub-
stances which act as solvents for the benzole and homologues contained
therein without, at the same time, causing them to undergo any
chemical change, and,, while it has been found that all known solvents
of benzole will effect this purpose, I prefer to place coal gas in con-
tact with certain hydrocarbons, such as petroleum, schist, and mineral
oils, and the higher boiling. varieties of coal tar naptha, as these
hydrocarbons are easily procurable and interfere little, if at all, with
the illuminating power of coal gas, and by mere distillation the said
benzole and its homologues may be separately obtained from their
solution therein, and the solvent rendered again fit for renewed
application.
As an example I proceed as follows:-In those cases in which it is
essential not to injure the luminosity of coal gas by depriving it of its
benzole I prefer to employ as absorbing agents the higher boiling
varieties of coal tar naptha the boiling points of which range from
130 degrees Centigrade upward, and it has been found that by placing

page_text: coal gas in contact with such hydrocarbons they will take up benzole
and its homologues from the coal gas while the latter becomes charged
with the vapours of the liquid hydrocarbons employed. Although any
suitable apparatus, may be made use of in order to effect the contact
of coal gas with the absorbing agent I prefer the employment of the
common coal gas purifiers or so-called scrubbers. The gas enters at
the bottom of the apparatus, and while ascending it meets a shower
of finely divided coal tar naptha which descends from the top of the
scrubber, and at a rate varying, say, from 20 to 40 gallons for every
10,000 cubic feet of gas traversing the apparatus.
This operation is
effected after the final purification of the coal gas and immediately before
its passage to the gas holders. The liquid hydrocarbon which arrives at
the bottom of the apparatus charged with benzole is drawn into a still
or other suitable vessel which is heated by steam or otherwise to a tem-
perature of about 130 degrees Centigrade. The distillate or hydrocarbon
obtained by this distillation, which generally amounts to ten or fifteen
per cent. of the whole liquid, contains chiefly benzole and toluole, which
formerly were diffused in the coal gas, while the residue in the still is
again transferred to the scrubber for renewed application.
Although I have described one way in which the separation of benzole
from coal gas is effected, and which is preferable in such cases where
coal gas is used as an illuminating agent, I however claim the use of
all known solvents of benzole, provided they have no chemical action
upon it, and I especially mention petroleum hydrocarbons, schist, and
mineral oils, liquid and solid. fats and resins, coal tar, and coal tar
napthas, heavy oils, pitch, and similar substances.
In witness whereof, I, the said William Robert Lake, have hereunto
set my hand and seal, this Sixteenth day of August, in the
year of our Lord One thousand eight hundred and sixty-nine.
Witness,,
WILLIAM ROBERT LAKE. (L.S.)