IMPROVEMENTS IN OBTAINING PRODUCTS FROM TAR
Year: 1852

page_text: LETTERS PATENT to George Shand, of Glasgow, in the County of
Lanark, and Andrew McLean, of Edinburgh, in the County
of Mid-Lothian, Scotland, Chemists, for the Invention of "IM-
PROVISIONAL SPECIFICATION left by the said George Shand and
Andrew McLean at the Office of the Commissioners of Patents,
with their Petition, on the 5th November 1852.
We, GEORGE SHAND, of Glasgow, in the County of Lanark, and
ANDREW MCLEAN, of Edinburgh, in the County of Mid-Lothian,
Scotland, Chemists, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN OBTAINING PRODUCTS FROM TAR" to be as
follows:-
Our Invention consists in treating tar in the following manner :-We
put tar into a still, to which we apply heat to distil off all the naphtha;
we then raise the heat, and by so doing distil over an oil contain-
ing naphthaline. To obtain naphthaline from this oil we proceed as
follows:-We put into a still of any convenient construction this oil,
containing-naphthaline, to which we add a sufficient quantity of caustic
lime, or any other caustic alkaline or earthy substance, or oil of vitriol,

page_text: or any other acid, in order to separate impurities. We then apply
heat, and distil over a volatile oil containing (in a concentrated form)
the naphthaline, which naphthaline we separate from this distilled oil
by cooling it down to a temperature of about 40° Fahrenheit, and by
expression. The oil remaining after the separation of the naphthaline
we treat as follows:-We put this oil into a convenient still, and apply
heat of about 212° Fahrenheit by the use of steam, when a very light
oil distils over, and the oil which remains in the still after the distil-
lation of this light oil is also valuable. Thus we extract the following
htheline licht volatile oil and a heavier oil
די
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Shand and Andrew McLean in the
Great Seal Patent Office on the. 29th April 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
GEORGE SHAND, of Glasgow, in the County of Lanark, and ANDREW
MCLEAN, of Edinburgh, in the County of Mid-Lothian, Scotland;
Chemists, send greeting:
.
WHEREAS Her most Excellent. Majesty. Queen Victoria, by Her
Letters Patent, bearing. date the Fifth day of November, in the
-year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto us, the said George Shand and Andrew
McLean Her especial license that, we, the said George Shand and..
Andrew McLean, our executors, administrators, and assigns,..or such
others as we, the said. George Shand and Andrew.. McLean, our;
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 Britain and
Ireland, the Channel Íslands, and Isle of Man, our Invention for "Iμ-
PROVEMENTS IN EXTRACTING PRODUCTS FROM TAR," upon the condition.
(amongst others) that we, the said George Shand and. Andrew M.Lean,
by an instrument in writing under our hands and seals, or under, the

page_text: hand and seal of one of us, 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 George Shand (on behalf of
myself and of the said Andrew McLean), do hereby declare the nature
of our said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the
following statement (that is to say):
"
Our Invention of "Improvements in Extracting Products from Tar'
has for its object the treatment of tar for the purpose of extracting its
products, and rendering them available for useful purposes, whether the
tar to be so treated be obtained from wood, coal, or animal substances
or matters.
And for the accomplishment of this object we submit the tar to the
following processes:-In the first place we distil over from coal or gas
tar all the crude or rough naphtha and ammonia in the usual way, and
by further distillation obtain "pitch oil," or "tar oil," or "creosote oil,"
which we call crude naphthaline oil.
Secondly, we purify this oil by means of acids and alkalies in the
manner herein-after particularly described, and extract from the oil so
purified the naphthaline, and also a light and a heavier oil contained
therein.
And, lastly, we submit tar obtained from wood or animal substances
to the same. processes in order to extract therefrom the crude oil to
purify it, and to separate from it the purified oils and the denser
substance contained therein.
We now proceed to describe the first part of the process or series of
processes pursued under our Invention:-We take coal or gas tar
and put it into a still of any convenient construction, with a worm and
condensing apparatus attached, and by means of steam passed into the
still from a steam boiler we distil over the crude or rough-naphtha and
ammonia in the usual way, until the crude naphtha coming over from
the still becomes of the specific gravity of about 910 degrees (water

page_text: being considered 1000°). We then shut off the steam, and by the
application of heat from a fire distil over a quantity of. water; and an
oil commonly called "pitch oil," or "tar oil," or "creosote oil," and
which we call crude naphthaline oil. We continue. the distillation
until the oil reaches the specific gravity of about 990 degrees, when
we withdraw the fire and run off in a heated state the residue of the
pitch in the still, and cool it in the usual way. A further quantity of
oil may be extracted from the pitch by subjecting it to a strong fire
heat in a retort, with a worm and condensing apparatus attached.
We now proceed to describe the second part of the process or
processes pursued under our Invention. (viz.), that relating to the puri-
fication of the "crude naphthaline oil," produced in the manner just
described, and the extraction therefrom of the naphthaline, and. oils
contained therein :-For this purpose we put the "crude naphthaline
oil" into a leaden vessel, and to every one hundred gallons gradually
add about fifteen gallons of sulphuric acid of the specific gravity of
about 1-830, and continually stir the mixture until the acid has
combined with all the impurities with which it can combine.:. We
then allow the contents of the vessel to settle and draw off the clear
liquor into another vessel, when we.gradually add to every one hundred
gallons of oil about ten gallons of caustic alkali of.the specific gravity
of about 1.350, and continually stir the mixture until any excess of
acid left in the oil is neutralized, and all other impurities with which
the alkali can combine are carried down. We then allow the contents
of the vessel to settle, and draw off the clear liquor, which we put into
a still of any convenient construction, with a worm and condensing
apparatus attached, and by the application of heat from a fire we distil
.over the oil into a vessel put there for the purpose of receiving it,
-until the oil coming over reaches the specific gravity of about 940
..degrees. We then run the oil from the still into a second vessel
(leaving the former product of the distillation to be separately treated
in the manner herein-after described), and continue this process of
.distillation until the contents of the still are run off. We then take
the oil so distilled, and treat it with a small quantity of caustic
magnesia or other substance in a dry state for the purpose of absorbing

page_text: any trace of water remaining in it. We then allow the contents to
settle and filter the oil, when it is ready for use, either alone or mixed
with other oils. We call the oil produced in the manner described
purified heavy naphthaline oil." We now take the former product
of the distillation of the "crude naphthaline oil" before mentioned,
and put it into any convenient still, with a worm and condensing
apparatus attached, and to every gallon of oil we add about one pound
weight of caustic lime or burned lime shells, and having stirred the
oil and lime well together we apply a gentle heat from a fire, and distil
over a light volatile oil, which we afterwards rectify by means of steam
from a steam boiler passed into any convenient still, with a worm and
condensing apparatus attached. The oil thus produced is useful for
solvent and other purposes. We continue the distillation until the
product thereof reaches the specific gravity of about 910 degrees,
when we apply a stronger heat from the fire and run the oil from
the still into a second vessel, continuing the operation until the
contents of the still are distilled over. We then allow the oil last
distilled to cool down to a temperature of about from 80 degrees to
40 degrees Fahrenheit, when the naphthaline will be deposited at the
bottom of the vessel. The naphthaline is separated from the oil by
filtration and by expression. The oil from which the naphthaline has
been separated, and which we call "light naphthaline oil," is treated
with magnesia or other substance in a dry state to absorb any trace of
water, and being filtered is ready for use. Naphthaline may also be
obtained by treating the "purified heavy naphthaline oil" with caustic
lime in the same manner as above described. In order to purify the
naphthaline after its separation from the naphthaline oil we put it into
a retort or other convenient apparatus, and with a gentle heat sublinie
it in vapour into a wooden chamber, where it condenses in flakes of a
white color.
We now proceed to describe the last part of our Invention:-
This consists in applying the process or series of processes above
described to tar obtained from wood or animal substances. For this
purpose we take tar thus obtained, and treat it in a similar manner to
that described above in reference to coal or gas tar, and produce there-

page_text: from a crude oil. This crude oil is afterwards purified in a manner
similar to that described in reference to the purification of the "crude
'naphthaline oil" and the heavier and lighter oils, and also the denser
substance extracted and separated therefrom, such oils and denser sub-
stance being purified in the manner above described in reference to
the purification of the heavier and lighter naphthaline oils and 'the
naphthaline.
Having thus described the nature of our Invention, and in what
manner the same is to be performed," we would have it understood that
some of the apparatus and mode of proceeding above described may be
Ivaried without departing, from the spirit of our Invention; also, that
such apparatus forms no part of our Invention, except when used as
above described; also, that we do not claim as of our Invention the
,first part of the process of series of processes herein-before described,
.(viz.,) that relating to the production of "crude naphthaline oil." But
what we claim as of our Invention is, First, the purification of the
crude oils produced from tar by distillation as described. Secondly, the
further treatment of such oils in a purified state, and the separation
therefrom of the heavier and lighter oils and the denser substance con
⚫tained therein, as described. And, 'lastly, the purification of such last-
-mentioned products as described..
... In witness whereof; I, the said George Shand, liave hereunto
set my hand and seal, this Ninth day of April, in the year of
our Lord One thousand eight hundred and fifty-three."❤
“GEORGE "SHAND G