IMPROVEMENTS IN DISTILLING COAL AND PEAT AND BITUMINOUS AND COALY MINERALS, AND IN THE TREATMENT OF THE PRODUCTS THEREPROM
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Charles Humfrey and Charles
Humfrey the younger at the Office of the Commissioners of Patents,
with their Petition, on the 23rd November 1860.
We, CHARLES HUMFREY and CHARLES HUMFREY the younger, both of
Wareham, in the County of Dorset, Oil and Candle Manufacturers, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
DISTILLING COAL AND PEAT AND BITUMINOUS AND COALY MINERALS, AND IN THE
TREATMENT OF THE PRODUCTS THEREPROM," to be as follows:-
In distilling coals and coaly minerals for the purpose of obtaining oils
suitable for burning in lamps, and other purposes, the process heretofore
adopted has been to effect the decomposition of the mineral at a low tempera-
ture. Now we find that the mineral can (by using the precautions herein-before
described), be much more advantageously decomposed at a high temperature.
The temperature employed in the decomposition of the mineral materially
affects the quality of the products obtained, but in all cases the vapours as they
rise from the mineral, if exposed to a high temperature, are decomposed, or
resolve themselves into uncondensible gas and heavy carburets of hydrogen of
little commercial value.
We therefore construct and arrange the retorts in which the decomposition
of the mineral is effected in such fashion that the bottom on which the mineral
is placed is heated strongly, while the top and sides are kept comparatively
cold.
Into the retorts during the decomposition of the mineral, we introduce &

page_text: stream of gas entering at the end opposite to that at which the vapours pass
into the condensers.
The introduction of this stream of gas has the advantage of carrying off the
vapours into the condensers as soon as formed, instead of leaving them for a
long time in the retort, and these vapours being of high specific gravity, and
consequently of small volume and of very low specific heat, are, by the admix-
ture of the cold stream of gas, almost instantaneously cooled. The temperature
of the top and sides of the retorts must, however, be kept sufficiently high to
prevent the condensation thereon of the vapours which would in such case
trickle down the sides of the retorts, and coming into contact with the heated
bottom be subjected to an injurious action.
Were the decomposition of the mineral effected in an ordinary gas retort
which is heated not only at the bottom and at the sides, but also at the top, no
good result could be obtained, except by operating at a very low temperature,
but by using retorts constructed and set as we employ, and by introducing a
stream of gas, the heat employed in decomposing the mineral may advan-
tageously be pushed as far as the retort will bear.
Our process yields an abundant product of crude oil or tar, containing very
little heavy lubricating oil and scarcely any paraffine, the high heat we employ
in the decomposition of the mineral seeming to determine the formation of the
light carburets of hydrogen, in preference to the formation of heavy oil and
paraffine.
These light carburets of hydrogen, which constitute the great bulk of the
product, contain no trace of crystalizable paraffine, but rather resemble what
chemists call "etherine," or "etherole," and are perfectly adapted for burning
in lamps.
In operating on bituminous minerals, which are simply sandstones or shaleś
impregnated with tar formed by the previous destructive decomposition of coal
beds, our process is particularly advantageous. The black sandstone of Coal-
brook-dale is an example of this class of minerals. This sandstone holds
mechanically the tar, and parts with it with difficulty, and to effect the opera-
tion advantageously a high temperature is required, but the vapours as they
rise are exceedingly susceptible of decomposition if left exposed to such high
temperature.
In operating on this latter class of minerals, the stream of gas may be
replaced by a current of steam, though we prefer the introduction of a stream
of gas; but in operating on coals and coaly minerals, where destructive distilla-
tion is essential, the desired products, not pre-existing in the mineral, we 'find
that steam cannot be advantageously employed.

page_text: By gas we mean the uncondeusible products of the decomposition of the
mineral, and of this there is a large quantity produced, and as this gas can be
used over and over again, there is always an abundant supply. The same
general principles are applicable to the destructive distillation of peat.
The crude oil thus obtained is refined by treating it (as is well known) with
concentrated sulphuric acid, which throws down a large quantity of black acid
pitch.
Now, our Invention further relates to obtaining from this acid pitch the
alkaloid bases formed by the destructive distillation of the mineral, especially
the base known as "analine."