Volatile Liquid Hydro-carbons.
Year: 1885

page_text: Volatile Liquid Hydro-carbons.
We JOHN LUCAS BALFOUR of Millfield House Tamworth in the County of
Warwick Manufacturer and JOSIAH LANE of Kingsbury near Tamworth afore-
said Manufacturing Chemist do hereby declare the nature of the said Invention
for IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS AND VOLATILE
LIQUID HYDRO-CARBONS to be as follows:-
--
In the ordinary method of manufacturing illuminating gas coal is subjected to
destructive distillation the principal products being illuminating gas and certain
liquid volatile hydro-carbons which are mostly associated with pitch constituting
the coal gas tar.
The distillation of the tar separates the greater part of the
hydro-carbons which by fractional distillation and other well known processes are
separated. But the pitch which forms the residuum of the distillatory process
contains a considerable proportion of some of the valuable volatile hydro-carbons
referred to and the object of the said invention is to recover these from coal.tar
pitch and at the same time to increase their production in the distillation of coal
for the manufacture of illuminating gas The illuminating power of the gas made
according to the said invention may be regulated in the manner hereinafter
described.
The said invention consists in manufacturing illuminating gas and the volatile
liquid bydro-carbons formed in the destructive distillation of coal by employing a
mixture of coal and coal tar pitch instead of coal simply in manufacturing
illuminating gas.
By the admixture of coal tar pitch with coal in the manufacture of illuminating
gas not only are the volatile hydro-carbons contained in the pitch recovered.but the
carbonisation of the pitch promotes the formation of an additional proportion of
the said hydrocarbons in the decomposition of the coal by heat. The coke produced
by the carbonisation of a mixture of coal and coal tar pitch is of superior quality
being denser and where the coal contains sulphur the illuminating gas as well as
the coke produced contain a less proportion of sulphur than is contained in the
coke from the same coal without admixture of pitch.
The manufacture of illuminating gas and the volatile liquid hydro-carbons
produced in the said manufacture and commonly called residual products is

page_text: conducted in gas retorts of the ordinary construction and generally the process is
conducted as the ordinary manufacture of illuminating gas is conducted excepting
that we employ a mixture of coal and coal tar pitch instead of coal only.
The proportions we have found answer well in practice are one part by weight
of coal tar pitch to from ten to twenty parts by weight of coal but we do not limit
ourselves to any proportions as these have to be varied according to the quality of
the coal employed.
•
The illuminating quality of the gas produced may be regulated by removing
more or less the vapour of benzole contained in it by the process commonly called
washing or scrubbing.

page_text: Improvements in the Manufacture of Illuminating Gas and
Volatile Liquid Hydro-carbons.
We JOHN LUCAS BALFOUR of Millfield House, Tamworth in the County of
Warwick, Manufacturer and JOSIAH LANE of Kingsbury near Tamworth aforesaid
Manufacturing Chemist, 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:-
In the ordinary method of manufacturing illuminating gas, coal is subjected to
destructive distillation the principal products, being illuminating gas and certain
liquid volatile bydro carbons which are mostly associated with pitch constituting
the coal gas tar. The distillation of the tar separates the greater part of the
hydrocarbons which by fractional distillation and other well known processes are
separated from each other. But the pitch which forms the residuum of the
distillatory process contains a considerable proportion of some of the valuable
volatile hydrocarbons referred to and the object of the said invention is to recover
these from coal tar pitch and at the same time to increase their production in the
distillation of coal for the manufacture of illuminating gas The illuminating
power of the gas made according to the said invention may be regulated in the
manner herein after described.
The said invention consists in manufacturing illuminating gas and the volatile
liquid hydro carbons formed in the destructive distillation of coal by employing a
mixture of coal and coal tar pitch instead of coal simply in manufacturing
illuminating gas.
By the admixture of coal tar pitch with coal in the manufacture of illuminating
gas not only are the volatile hydrocarbons contained in the pitch recovered but the
carbonisation of the pitch promotes the formation of an additional proportion of
the said hydro carbons in the decomposition of the coal by heat. The coke
produced by the carbonisation of a mixture of coal and coal tar pitch is of superior.
quality being denser and where the coal contains sulphur the illuminating gas as
well as the coke produced contain a less proportion of sulphur compounds than is
contained in the coke from the same coal without admixture of pitch.
We conduct the manufacture of illuminating gas and the volatile liquid hydro-
carbons produced in the said manufacture and commonly called residual products
in gas retorts of the ordinary construction and generally the process is conducted as
the ordinary manufacture of illuminating gas is conducted excepting that we
employ a mixture of coal and coal tar pitch instead of employing coal only.
The proportions we have found to answer well in practice are one part by weight
of coal tar pitch to from ten to twenty parts by weight of coal but we do not limit
ourselves to any proportions as these have to be varied according to the quality of
the coal employed.
In employing coal of ordinary quality we find that a mixture of five parts by
weight of coal tar pitch to ninety five parts by weight of coal yields excellent
results. By the use of coal and coal tar pitch in the last described proportions the

page_text: further advantage results that the amount of tar produced yields an amount of
coal tar pitch equal or nearly equal to the quantity of coal tar pitch originally
mixed with the coal so that the process so conducted is self supplying so far as coal
tar pitch is concerned. As however the proportion of coal tar pitch required to
produce the best results depends largely on the quality of the coal used we wish it
to be understood that we do not limit ourselves to the proportions of coal and coal
tar pitch herein given a bituminous coal or coal which distilled by itself yields a
more than average quantity of tar requiring a less proportion of coal tar pitch to be
mixed with it while a drier kind of coal or coal yielding less than the average
quantity of tar requires a larger proportion of coal tar pitch to be mixed with it
when used in carrying out our invention.
By the admixture of coal tar pitch with the coal employed in manufacturing
illuminating gas, the illuminating power of the gas and its volume are increased.
An additional quantity of benzole may be obtained from the gas, the yield of tar
and ammoniacal liquor is increased and the residual coke is denser than that
obtained in the ordinary method of manufacture and when the coal employed
contains sulphur the coke obtained is freer from sulphur compounds than when it
is treated in the ordinary way.
We do not confine ourselves to the use of any particular kind of coal tar pitch
but we prefer to use the pitch known in commerce as soft coal tar pitch. The said
soft coal tar pitch is pitch into which creosote oil has been injected after the com-
pletion of the distillatory process of which the said pitch was the residuum and
while the pitch was still in the distillatory apparatus. The object of impregnating
the pitch in the distillatory apparatus with creosote oil is to soften the pitch and to
produce what is known in commerce as soft coal tar pitch.
In charging the retorts with the mixture of coal and coal tar pitch it is desirable
to have the materials uniformly mixed or incorporated. This object is conveniently
effected in the following manner. The coal tar pitch having been broken into
fragments, say about as large as walnuts, the required quantity of the said fragments
is distributed uniformly over the proper quantity of coal laid down in front of the
retorts for the charging of the said retorts. The compound layer of coal and coal
tar pitch is charged into the retorts by the workmen in the ordinary way and the
distillatory or gas making process is conducted in the usual way.
The illuminating quality of the gas produced may be regulated by removing
more or less the vapour of benzole contained in it by the process commonly called
washing or scrubbing.
Having now particularly described and ascertained the nature of this invention
and the manner in which the same is to be performed we declare that we claim
as this invention of "Improvements in the manufacture of illuminating gas and
volatile liquid hydrocarbons:"
The employment or use of a mixture of coal and coal tar pitch in the said
manufacture in place of coal alone used in the ordinary method of manufacture, the
said manufacture according to this invention being conducted according to the
ordinary method excepting that a mixture of coal and coal tar pitch is substituted
for coal substantially as herein described.
Dated this Twelfth day of July 1886