IMPROVEMENTS IN THE MANUFACTURE OF COAL GAS
Year: 1852

page_text: LETTERS PATENT to John Clay, of Cottingham, in the East
Riding of the County of York, Esquire, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF COAL GAS."
Scaled the 30th April 1853, and dated the 18th December 1852.
PROVISIONAL SPECIFICATION left by the said John Clay at
the Office of the Commissioners of Patents, with his Petition,
on the 18th December 1852.
I, JOHN CLAY, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF COAL GAS" to be as
follows:-
The object of this Invention is to effect the perfect purification of
carburetted hydrogen gas in an economical manner. To this end,
I propose to employ (either alone or in combination with other
matters already in use) peat charcoal, which possesses the property
of absorbing certain noxious gases, as sulphuretted hydrogen, and
of retaining them under ordinary atmospheric temperatures. I
pass the gas through or over a bed or beds of this material, and
during this passage, the volatile impurities which come over from
the retort with the carburetted hydrogen will be taken up or

page_text: absorbed by the peat charcoal. In some cases I find it desirable
(according to the quality of the coal employed in generating the
gas) to use the ordinary lime purifier, or to use salt nitrate of soda
or potash, or copperas, either, any, or all of these, or even of other
known purifying materials, in combination with 'the peat charcoal.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said John Clay in the Great Seal Patent
Office on the 18th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN CLAY, of Cottingham, in the East Riding of the County of
York, Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of December, 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 suc-
cessors, give and grant unto me, the said John Clay, Her special
licence that I, the said John Clay, my executors, administrators, and
assigns, or such others as I, the said John Clay, my executors, ad-
ministrators, 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 COAL GAS," upon the condition (amongst others)
that I, the said John Clay, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the saine was to be per-
formed, 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 John Clay, do hereby declare
the nature of my said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and
by the following statement (that is to say):-
:-
My Invention of improvements in the manufacture of coal gas
relates to an improved mode of purifying ordinary carburetted
hydrogen gas, and removing therefrom certain noxious gases, which
materially impair its illuminating powers. The noxious gases
which require to be removed consist principally of ammonia and
sulphuretted hydrogen; and this object has hitherto been usually
effected by causing the impure carburetted hydrogen gas to pass
through a purifier, or apparatus containing lime, or some other
chemical agent or agents which have a strong affinity for the
noxious gases above mentioned. The object of the present Inven-
tion is to effect the removal of these noxious gases, and the perfect
purification of carburetted hydrogen gas in a more effectual and
economical manner than according to the ordinary process. For
this purpose, instead of using lime alone, I employ peat charcoal, in
combination with lime or other matters, some of which have been
heretofore used separately for similar purposes. These agents must
possess the property of absorbing ammonia, sulphuretted hydrogen,
and the other usual gaseous impurities of carburetted hydrogen.
The peat charcoal is made in the ordinary manner; and when the
peat has been converted by burning into charcoal, it is to be reduced
to powder, and mixed with common salt and pulverized iron ore, in
the proportions of two parts of peat charcoal to one part of pul-
verized common salt and one part of pulverized iron ore. The iron
ore should contain an oxide of iron, and I employ, by preference,
that kind of ore known as the red hematite. When these ingre-
dients have been well mixed, they will be ready for use, and are
employed in precisely the same way as lime is now used in the
ordinary dry lime purifier. No change in the apparatus of the gas
works, and no additional attention, is required. The workmen,
therefore, have only to place the combined ingredients in the
ordinary purifier, instead of the lime, and allow the gas to pass
through in the ordinary manner. In some cases I find it desirable,
according to the quality of coal that is used for the manufacture of

page_text: the carburetted hydrogen gas, to employ lime in combination with
the other materials; this, however, is not absolutely necessary, and
may, in fact, be dispensed with in situations where the expense of
lime would be an object worth saving. It be will found, that not
only will the combined ingredients above mentioned more effectually
purify the gas, but that the purifier will not require replenishing
with the purifying materials so frequently as is now the case; and,
furthermore, that the product obtained from the purifier, when the
materials are saturated with the gaseous impurities, will be a most
valuable artificial manure.
Having now described my Invention, and the best means with
which I am at present acquainted for carrying the same into effect,
I would observe, in conclusion, that I do not mean or intend to
claim the exclusive right to employ peat charcoal alone for purify-
ing carburetted hydrogen gas, nor do I intend to confine myself to
the precise proportions in which the several ingredients are to be
mixed, as above set forth; but that which I consider to be new, and
therefore wish to claim as my Invention or discovery, is, the use of
peat charcoal in combination with common salt and iron ore, or
oxide of iron, for the purification of coal gas as above described.
In witness whereof, I, the said John Clay, have hereunto set my
hand and seal, this Eleventh day of June, in the year of our
Lord One thousand eight hundred and fifty-three.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
JOHN CLAY. (L.S.)