IMPROVEMENTS IN PURIFYING AND INCREASING THE ILLUMINATING POWER OF GAS
Year: 1879

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for the Invention of "IMPROVEMENTS IN PURIFYING AND
INCREASING THE ILLUMINATING POWER OF GAS." A. communication from
abroad by Orazio Lugo, of Flushing, in the State of New York, United States
of America.
Sealed the 20th June 1879, and dated the 9th April 1879.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 9th April 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. " IMPROVE-
MENTS IN PURIFYING AND INCREASING THE ILLUMINATING POWER OF GAS." A
communication from abroad by Orazio Lugo, of Flushing, in the State of New
York, United States of America.
The Invention consists in purifying illuminating gas by passing the same mixed
with air through animal charcoal; also in preventing the absorption of illuminants
of the gas by charging the black with a suitable correlative to such illuminants,
and may be carried out as follows:-The charcoal used for this purpose is moistened
with coal tar, or coal tar and water, or water only, and then charged (either wet or
after it has dried) into one or more vessels or purifiers through which the gas has to
pass after having been mixed with a small quantity of atmospheric air. Part of the
oxigen in the air unites with the sulphur in the gas, another part decomposes the
sulphuretted hydrogen so as to precipitate the sulphur into the charcoal, and part of
the nitrogen of the air forms with part of the remaining hydrogen ammonia-bases.
Instead of coal tar other suitable substances may be used for charging the charcoal
in order to prevent the absorption of heavy hydrocarbons or other illuminants.
When the charcoal finally becomes inactive it may be revivified or washed and re-
used after the sulphur has been extracted by a suitable solvent. For eliminating
sulphuretted bydrogen contained in gas the charcoal may be mixed with oxide of
iron, tin, manganese ore, or other substances which decompose the sulphuretted
hydrogen.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Herbert John Haddan in the Great Seal Patent Office on the 7th
October 1879.
"
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. IMPROVE-
MENTS IN PURIFYING AND INCREASING THE ILLUMINATING POWER OF GAS." A
communication from abroad by Orazio Lugo, of Flushing, in the State of New York,
United States of America.
The usual mode of purifying illuminating gas, whether manufactured by the
destrucive distillation of coal or by the decomposition of steam or water in contact
with highly heated carbon, and subsequently carburetted and fixed, is to condense
the same, scrub it, and then pass it through lime, or subject it to the absorbent action
of finely divided ferric oxide, or in order to get rid of the carbon dioxide as well, to
the action of a mixture of equal parts of ferrous sulphate and saw dust with half the
weight of slaked lime, whereby a mixture containing slaked lime, hydrated ferric
oxide, and sulphate of lime made porous with saw dust is obtained.
Notwithstanding these processes however for the purification of gas, quantities of
impurities, such as sulphur and it's compounds, ammoniacal and other compounds,
remain in the gas, greatly affecting the illuminating power of the gas as well as
proving injurious to health and destructive to property. Gas has also been purified
by passing it through animal charcoal, but when this is used alone after a short time
it loses its power of absorbing impurities and has then to be washed with steam or
water, or have atmospheric air blown through it, or it has to be revivified by heat;
while used alone it also reduces the candle power of the gas passed through it and
greatly diminishes its bulk.
The object of this Invention is thoroughly to purify illuminating gas, to make the
operation continuous, and to purify the gas without detracting from its illuminating
power and without causing any appreciable diminution in bulk, and to this end,-
This Invention consists generally in increasing the power of animal charcoal to
eliminate those substances from illuminating gas which are considered impurities,
and particularly in passing the gas to be purified through the animal charcoal
together with atmospheric air, as well as in charging the charcoal with a substance
which will prevent it from depriving the gas of illuminants.
To carry this Invention, into effect the charcoal (which may be either new or
spent) is to be moistened with coal tar, or with coal tar and water, or with water
alone, and then this mass to be charged into one or more vessels, which then con-
stitute the purifiers. The mass may be put into the vessels while still wet or after*
it has dried; it will soon become dry in use any way. Through these vessels the
gas is to pass, but before it is admitted a small quantity of atmospheric air is to be
introduced into it at the retortes or at the stand pipe or mains beyond in order to
insure a thorough admixture; the quantity of air to be introduced may vary from
8/10 to 21 % of the bulk of the gas to be purified. The quantity of air will
however depend upon the impurities of the gas. Any suitable mixing device for
thoroughly mixing the admitted air with the gas may be located at any point in
the mains between the retorts and the bone black purifiers, or even at the point of
admission in the purifier.
The oxygen of the air partly unites with the sulphur to form soluble salts, and
the rest combines totally with the bydrogen of the sulphuretted and other hydrogen
sulphur compounds to form water, and part of the sulphur of the sulphuretted
hydrogen and other sulphur compounds is precipitated in a free state in the char-

page_text: By the
coal, while its nitrogen partly goes to form, with part of the remaining hydrogen,
ammonia bases. No free oxygen passes off with the purified gas, while if any
nitrogen goes over, the quantity is so small that it is not detrimental.
application of air in this manner the process is rendered continuous as the charcoal
is constantly kept active for a great length of time.
When the charcoal finally becomes exhausted it may then either be sold at a
profit for the valuable ammoniacal salts it contains, or it may be revivified or be
washed and have the sulphur dissolved out of it by a suitable sulphur solvent for
re-use.
By charging the bone black with coal tar the black is to be prevented from taking
out of the gas passing through any olifiant gas or other heavy hydrocarbons serving
as illuminants. The black may be treated either before or after putting it into the
vessels, as may be most convenient and suitable with any substance correlative to
the illuminants of the gas, that is, with any substance which will saturate the
black in such a manner that it will not take up such illuminants. It is particularly
described coal tar because that is most readily to hand, but its hydrocarbon dis-
tillates or the benzol series will answer.
In the case of coal gas the sulphuretted hydrogen with which it is contaminated
is not only taken up as just described, but the illuminating power of the gas, which
is somewhat reduced, if passed through dry animal charcoal or bone black, is not
only not decreased when air is used and the animal charcoal or bone black is wet
with tar, but is actually improved inasmuch as it gives a much whiter flame of the
same candle power as the gas not passed through animal charcoal or boneblack
at all.
By the old method when purification was effected by the use of lime, the sul-
phuretted hydrogen and carbonic acid were absorbed by the lime, and the result
was of course a great loss in the original bulk of the gas. Now, by the herein
described process the sulphur and hydrogen are separated, the sulphur remaining
in the charcoal and its hydrogen passing through with the gas while the carbonic
acid passes through entire, and although it passes through unchanged, it is
sufficiently carburetted not to detract from the illuminating power of the gas.
There is thus practically the same bulk of gas after purification as before this
operation, and it will be at once appreciated that a great loss is prevented without
detriment to the consumer.
A striking advantage of this process is that it unites the scrubbing and purifying
operations, for the gas may be passed directly from the condenser into the
purifiers.
Sometimes common charcoal may be used, wet, as described, and with the intro-
duction of air. To eliminate sulphuretted hydrogen the charcoal may be mixed
with a substance which will of itself decompose sulphuretted hydrogen contained in
gas, such as oxide of iron, tin, manganese, ore, &c.
When the gas issues from the described purifiers it is entirely free from am-
moniacal and sulphur compounds, and is nearly inodorous.
When the charcoal is removed from the purifiers it is also inodorous, and is in no
sense offensive and disgusting like gas lime.
1. The process of purifying illuminating gas by passing the same mixed with air
through animal charcoal treated as described.
2. In the purification of illuminating gas by animal charcoal, the process of pre-
venting absorption of illuminants of the gas by charging the black with a suitable
correlative to such illuminants.
3. The composition to be used in the purification of gas consisting of animal black
and coal tar. .

page_text: 4. The use of animal black, wet or moistened with water, for purifying illuminating
gas, all substantially as described and for the purpose set forth.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Sixth day of October, A.D. 1879.
TARDAN
표
H. J. HADDAN
(LMS.)