IMPROVEMENTS IN THE MANU- PACTURE OF ILLUMINATING GAS
Year: 1870

page_text: LETTERS PATENT to William Young, Manager of the Chemical
Works, Magdalen Bridge, in the County of Mid Lothian, and
Peter Brash, of Leith, in the same County, Soap, Candle, and Oil
Manufacturer, for the Invention of "IMPROVEMENTS IN THE MANU-
PACTURE OF ILLUMINATING GAS."
Sealed the 10th September 1870, and dated the 6th April 1870.
PROVISIONAL SPECIFICATION left by the said William Young and
Peter Brash at the Office of the Commissioners of Patents, with
their Petition, on the 6th April 1870.
We, WILLIAM YOUNG, Manager of the Chemical Works, Magdalen
Bridge, in the County of Mid Lothian, and PETER BRASU, of Leith,
in the same County, Soap, Candle, and Oil Manufacturer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN
MANUFACTURE OF ILLUMINATING GAS," to be as follows:-
THE
This Invention has for its object the manufacture of illuminating gas
from certain residual products from the refining of paraffin oils. These
products are the tars resulting from the treatment of the oils with acids

page_text: and alkalies, and are known as acid and alkaline tars. To prepare these
tars for the purpose of manufacturing gas they are placed in a suitable
vessel and are boiled with open steam. The acid and alkaline tars being
mixed so that they neutralize each other, or if there is not sufficient
alkali present common salt or any cheap alkaline substance may be used
for that purpose. By this means the oily materials are separated from
the salts formed by the combination of the acid and alkali and float
upon the surface of the water formed by the condensation of the steam.
These oily materials may now be used for the manufacture of gas, but
to remove still further the impurities and make them more suitable for
the purpose we prefer distilling them in any suitable distilling vessel.
We also prefer removing the more volatile portions of the distillate, by
which is becomes perfectly safe for storage and transit. To convert
the prepared oily material into illuminating gas the ordinary coal gas
retorts may be used and a similar heat applied. The oily material is
run into the retort by a scaled pipe placed in such a position that the
oily material is brought into contact with the heated surface of the
retort. Or the oily material may be used for the purpose of improving
the illuminating power and increasing the quantity of gas from the
poorer class of coals by running in the material during the time of the
distillation, or the coal may be saturated with the oily material before
being thrown into the retort. By any of the above methods a large
quantity of highly illuminating gas is produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Young and Peter Brash in the Great
Seal Patent Office on the 6th October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
YOUNG, Manager of the Chemical Works, Magdalen Bridge, in the
County of Mid Lothian, and PETER BRASII, of Leith, in the same
County, Soap, Candle, and Oil Manufacturer, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of April, in the year of our
Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give, and-
grant unto us, the said William Young and Peter Brash, Her special:

page_text: licence that we, the said William Young and Peter Brash, our executors,
administrators, and assigns, or such others as we, the said William
Young and Peter Brash, 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 Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING
Gas," upon the condition (amongst others) that we, the said William
Young and Peter Brash, our executors or administrators, by an instrument
in writing under our, or their hands and seals, or under the hand
and seal of one of us or them, 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 we, the said William Young and Peter Brash,
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 thereof, that is to say :-
This Invention has for its object the manufacture of illuminating gas
from certain residual products from the refining of paraffin and such
like hydrocarbon oil. In the refining of these oils they are alternately
treated with acids and alkalics. For this purpose the oils are placed
in agitating vessels and strong acid added (sulphuric in preference),
the whole is then well stirred or mixed so as to bring the acid and
oils into contact. On allowing the mixed oil and acid to stand the
acid and the impurities settle to the bottom and appear as a thick
far which is drawn off. The remaining oils are then well washed with
water, and treated with caustic soda in the same way as with the acid
which also in a similar manner removes impurities in the form of tar.
The mixed refuse products (acid and alkaline tars) are at present a
great nuisance to the oil refiners, and have not as far as we know been
applied to any useful purpose in the arts. Our Invention has for its
object the application of these tars to the manufacture of illuminating
gas. To prepare them for this purpose the acid tar is placed in a
suitable vessel (by preference lined with lead) and boiled up with open
Steam. The condensed water from the steam combines with the acid

page_text: and sinks to the bottom and is drawn off. The alkaline tar is then run
in and the whole of the tar is again boiled up. In this way any acid
that may be present is neutralized and leaves the tars in a purified state
floating on the surface of the solution of salts, alkali, and other
matters. (The alkali may be recovered by evaporation.) The purified
tar can now be used for gas making by mixing it with small coal as
herein-after described, or by running it into the retorts after the charge
of coal has been introduced, but it does not do so well to run it into
the retorts in this state as it is apt to choke up the running in pipe with
carbonaceous matter. To obviate this we distil the tar.
We prefer
removing the more volatile portions of the distillate, by which it becomes
perfectly safe for storage and transit. When this tar oil is used alone
for the manufacture of gas iron retorts are preferable to clay, being
less porous and better conductors of heat and the distilled tar oil is
used in preference. When the retorts are kept at a moderate gas
making heat and the oil delivered in a continuous stream, a large
volume of highly illuminating gas is produced.
This temperature
suffices to convert the oil into permanent gas, but is not sufficiently
high to decarbonize the gas to any great extent. In gas works where
clay retorts are wrought at high heats the best commercial result will
be obtained when the gases from the coal and oil are brought in contact
at the instant of decomposition. This can be accomplished by running
the oil into the retorts during the distillation of the charge of coal or by
intimately mixing the coal and oil before charging. We prefer common
household or splint coal for the purpose of this Patent, the coal should
be pulverized, or in the state known as dross or slack, and the oil may be
advantageously mixed in the proportion of 30 gallons per ton of coal; but
the proportion may be either less or more according to the quality of
gas desired. The oil in this case may be used in its undistilled state.
The oil when used alone or with coal gives a permanent gas differing in
this respect from gas produced from a mixture of coal and shale oils,
the oil is almost entirely free from sulphur, so that its purification is
exceedingly easy. In place of using coal as the mixing material any
substance giving a large yield of poor gas (such as peat, sawdust, or
spent bark) will answer the purpose. Either the acid or alkaline
tar may be used separately if desired; but the acid and alkali by pre-
ference arc first removed from them. The acid tar may be prepared
by adding to it common salt in such quantity that the sulphuric acid
may all be converted into sulphate of soda. The hydrochloric acid

page_text: produced escapes during the boiling, which is conducted in the manner
already described. The alkaline tar may be prepared by simply boiling
it with steam in the manner described and adding common salt,
allowing it to stand, when the tarry matter separates and floats on the
surface. It is however better and more economical to mix the acid and
alkaline tars and treat them together.
Having thus described the nature of our said Invention and the
manner of performing the same, we would have it understood that
what we claim is, the manufacture of illuminating gas as herein de-
scribed from the tar or tars resulting from the purification of paraffin
and such like hydrocarbon oil.
We also claim the manufacture of illuminating gas as herein dc-
scribed from the acid and alkaline tars resulting from the purification of
paraffin and such like hydrocarbon oil mixed together and treated
substantially as set forth.
We also claim the manufacture of illuminating gas as herein described
from a compound of coal or other substance yielding gas of low illumi-
nating power, and the tar or tars resulting from the purification of
paraffin or such like hydrocarbon oil.
In witness whereof, we, the said William Young and Peter Brash,
have hercunto set our hands and scals, this Fifth day of
October, in the year of our Lord One thousand eight hundred
and seventy.
WILLIAM YOUNG. (L.S.)
PETER BRASH.
(L.S.)