IMPROVEMENTS IN PURIFYING GAS, AND IN OBTAINING AND REPRODUCING MATERIALS USEFUL FOR THAT PURPOSE
Year: 1859

page_text: LETTERS PATENT to Richard Laming, of Hampstead, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN PURIFYING GAS, AND
IN OBTAINING AND REPRODUCING MATERIALS USEFUL FOR THAT PURPOSE."
Sealed the 13th December 1859, and dated the 20th June 1859.
PROVISIONAL SPECIFICATION left by the said. Richard. Laming at the
Office of the Commissioners of Patents, with his Petition, on the *20th
June 1859.
'
I, RICHARD LAMING, of. Hampstead, in the County of Middlesex, do
hereby 'declare the nature of the said Invention for "IMPROVEMENTS IN PURI-
FYING GAS, AND IN OBTAINING AND REPRODUCING MATERIALS USESUL FOR THAT
PURPOSE," to be as follows:-.
This Invention relates to the purification of gas from its sulphuretted hydro-
gen by certain metallic oxides, also to the previous or simultaneous removal
of!
great part or the whole of its carbonic acid by other means, and to the
production and revivification of chemical reagents made use of for either
purpose.
.It is based mainly upon the following facts:-
1. The affinity of precipitated and hydrated protoxide of manganese for
carbonic acid is superior to that of sulphuretted bydrogen, so that it cannot be
used for taking from gas the latter impurity exclusively.
2. The proto-carbonate of manganese, formed by taking carbonic acid from
impure gas, does not pass into a brown or revivifiable oxide by mere exposure
to the air, so as to become afterwards useful as a purifier from sulphuretted
hydrogen.
3. The said proto-carbonate readily, parts with carbonic acid to certain

page_text: alkaline and earthy reagents, and thus changes into precipitated and hydrated
protoxide of manganese, a substance which, like the hydrated sulphuret of
manganese, does become a brown revivifiable oxide by the action of the air.
4. Precipitated and hydrated proto-carbonate of iron does not retain its
carbonic acid in presence of the sulphuretted hydrogen of impure gas, and
therefore cannot be usefully employed to rid the gas of the former of those
two impurities.
And last, a solution of hydrosulphate of ammonia absorbs carbonic acid
from impure gas passing through it, giving up sulphuretted hydrogen in
exchange, a result which is promoted by the great volalility of the salt named.
The Invention is as follows:-Firstly, by means of scrubbing or washing
with its own condensed and washing liquor, I deprive gas of all or greater
portion of its carbonic acid, and with that operation I combine its final
purification from sulphuretted hydrogen by a revivifiable compound, either of
manganese or of iron. Or, in combination with the said final purification, I
remove carbonic acid, together with ammonia, by the previous use of a porous
mass soaked with the solution of a manganese or earthy salt.
Secondly, I produce a purifying material, containing a revivifiable compound
of manganese, by decomposing "chlorine waste," or muriate of manganese by a
caustic earth, by mixing the precipitated and hydrated protoxide of manganese
with porous matter, and by its further oxidation by exposure to the air, or by
exposing muriate of manganese to gas previously deprived of carbonic acid,
washing out the resulting muriate of ammonia, and exposing the washed mass
to the air for the hydrated sulphuret of manganese to change into a brown oxide.
I also produce and reproduce revivifiable compounds of manganese and of
iron, by treating protocarbonates of those metals by certain compounds of
sodium or potassium, and in some cases by a caustic earth.
Thirdly, I purify gas from sulphuretted hydrogen, and more or less perfectly
from carbonic acid and ammonia; also by passing it through a porous mass
containing muriate of manganese, or of lime mixed with precipitated manga-
nese, or iron in a higher state of hydrated oxidation than the protoxide, by
which means I form a muriate of ammonia, a carbonate of the saline base, and
a sulphide of manganese, or of iron. I combine with that process the repro-
duction of the purifying materials by exposing the mass to the action of
air, thus changing the sulphide into oxide, thereby raising the temperature of
the mass, and in consequence forming and volalilizing carbonate of ammonia,
while a saline muriate is also re-formed, which being fixed remains in the
material.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Laming in the Great Seal Patent Office on the
19th December 1859..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
LAMING, of Hampstead, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of June, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Richard Laming, Her special licence that I, the said Richard Laming,
my executors, administrators, and assigns, or such others as I, the said
Richard Laming, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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
PURIFYING GAS, AND IN OBTAINING AND REPRODUCING MATERIALS USEFUL FOR THAT
PURPOSE," upon the condition (amongst others) that I, the said Richard
Laming, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 I, the said Richard Laming, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say:-
The scrubbing of gas with gas or ammoniacal liquor, and also with water, is.
common; by the two-fold scrubbing it is easily freed from ammonia in combi-
nation with sulphuretted hydrogen and carbonic acid, while an increased
quantity of ammoniacal solution is thereby obtained. Ammoniacal or gas
liquor, without the subsequent use of water, will not suffice to remove from
gas all its ammonia; to do that completely, even with water, has hitherto
demanded so large a quantity of that fluid as to make the resulting ammo-
niacal washings weak and of inferior commercial, value. One part of this
Invention so combines the water-scrubbing with the ammoniacal liquor-
scrubbing of gas as to remove from it the whole of its ammonia in the form

page_text: of a comparatively strong solution, and at the same time to bring the whole of
that solution over and over again into contact with the gas, thereby effecting
to a considerable extent the removal of its carbonic acid, partly in exchange
for sulphuretted hydrogen, the removal of which afterward is easy and
economical. The improvement requires for its application a combination of
at least three scrubbers to be used consecutively; they may be of usual
dimensions and construction, but they must not all be fitted up and worked
alike. The first of the scrubbers, namely, that through which the gas passes
last, I supply with water made gradually to collect in an ordinary tumbling-
box or self-emptying vessel so situated as to discharge itself when sufficiently
full into a funnel communicating with a distributing pipe or pipes pierced
with small holes, and made to turn horizontally within the upper part of the
scrubber, and by which the water is from time to time spread equally over
the upper surface of the scrubbing materials. The speed with which the
water is allowed to collect in the self-emptying vessel should be a little greater
than is absolutely necessary to prevent the last portions of ammonia from
leaving the upper part of the scrubber with the passing gas; and within
certain limits the speed may be less as the numbers and altitudes of the
scrubbers are greater. With three moderate sized scrubbers of the usual
construction a discharge of water into the first of the series in the proportion
of about one gallon for each thousand cubic feet of gas passing, will, if pro-
perly distributed among the scrubbing materials, be sufficient. The water in
its downward passage through the material against the current of the gas
dissolves more and more ammonia, and eventually flows out at the lower part
of the scrubber to collect in a tank, from which pumps throw it into the
scrubber which is next in succession towards the source of the gas, not as
before in restricted quantity, and only occasionally by means of a tumbler or
self-emptying vessel, but constantly, and with a rapidity limited only by the
capacity of the pumps for delivering it directly into the funnel of the revolving
pipe or pipes, and their power of distributing it. For this second scrubber
there should be always a plentiful supply of washing liquid, and that is pro-
vided for by the liquor already used in it running out from its lower part back
again into the same tank from which it was raised; by which provision it
becomes abundantly used over and over again, while the tank is only gaining
a real accession to its contents equal to the measured quantity let into the
scrubber number one. The third scrubber in the series, I feed in like manner
as number two, but with liquor drawn from a second tank. This second tank
receives either a continual overflow from the first tank, or else occasionally the
whole or part of its contents by means of a pipe and cock_fitted for that

page_text: And
purpose, and also the liquor used in the third scrubber, which constantly runs
back into it. Every subsequent scrubber that the series may contain has its
separate tank, and is fed with liquor from it, as in the preceding cases.
I prefer that when the washing liquor in any tank becomes as strongly charged:
with ammonia as is the ordinary gas liquor of the works, that then the said
gas liquor also shall be gradually received into that particular tank from the
pipes in which it is condensed, and be used, mixed with the washings, in the
subsequent scrubbers; for that addition aids in removing carbonic acid from
the gas.
Or the condensed liquor may be used unmixed with the concen-
trated washings in the last scrubber of the series, the concentrated washings
being diverted from entering its apparatus of supply.
This Invention for reducing to the smallest possible quantity the fresh
water used after the ammoniacal solution is productive of another good result,
for whereas the entire removal of ammonia from the gas in the ordinary
manner of scrubbing with a large quantity of fresh water improves its
illuminating power only about ten per cent., the removal of all the ammonia
by the new method of working increases the illuminating power about fourteen
per cent.; and as the improvement in both cases is due to the removal from
the gas of the same impurities, the deficiency in one of them is to be ascribed
to the property which the excess of fresh water has, in common with other fresh
purifying materials, of saturating itself with the rich hydrocarbons of the gas.
The gas thus freed from its ammonia and a large portion of its carbonic acid;
together with other impurities, I next completely deprive of its sulphuretted
bydrogen. If I do this by the ordinary use of lime, wet or dry, I find that
that material is economised by the new method of scrubbing to the extent of
about one-third part of what would have been necessary had no scrubbing
been used; but I prefer to do the further purification of the gas from sul-
phuretted bydrogen by revivifiable oxide of manganese, which I make by
exposing certain substances (hydrated precipitates) to the oxidising influence
of the atmosphere, or by a mixture compounded of native sesquioxide or per-
oxide of manganese or of iron with hydrate of lime, which oxide and com-
pounds of oxides are also useful for entirely removing sulphuretted bydrogen
from gas that has not been submitted to the partial purification herein-before
described.
Native oxides of manganese and iron should be selected for this Invention
for friability and softness, the hard and granular kinds being far less energetic,
and if bydrated as well as soft and friable so much the better for my purpose.
Of the native oxides I prefer ochreous or brown hæmatite, and the mineral
called "wad." The native oxide, whether of manganese or iron, I prepare

page_text: for use by grinding it, or otherwise well incorporating it with half its weight
or other large proportion of caustic lime in the condition of hydrate, which
confers upon it a power of revivification it would not have without that addition,
and what is very important, I also thereby enable it on first being used to pass
more readily into the condition of sulphuret, by reason apparently of the
caustic lime freely taking sulphuretted hydrogen from the gas, and surrendering
it to the metallic element. Instead of lime, fine chalk may be mixed with the
native oxide; as it promotes the revivification of the used material, though it
has not the power of lime in the first instance to recommend it. Native oxides
generally are cheaper than those artificially made, but they are not, even when
used with lime, equal to them in purifying power; hence the economical
production of the artificial revivifiable oxides is a great desideratum.
Hydrated protoxide of manganese precipitated from the compounds of that
metal is unfit for the economical purification of gas from sulphuretted bydrogen,
because in the first place it elects to combine with carbonic acid in preference,
and having so combined, it remains afterwards a permanent carbonate of pro-
toxide of manganese not spontaneously revivifiable, however long exposed to
the atmosphere. The higher oxides of manganese are free from that objection,
for they have no tendency to excludé sulphuretted hydrogen by combining in
preference with carbonic acid. But these higher oxides cannot be precipitated
from the ordinary solutions or salts of manganese, for the simple reason that
they do not exist in them, compounds of these higher oxides being known only
in the scientific laboratory, and not as cheap commercial substances available
in abundance for the purposes of gas purifying. A revivifiable sesquioxide of
manganese may, however, be economically made as follows:-I take the
impure solution of hydrochlorate of manganese, known by the makers of
bleaching powder as "still waste," and having boiled off its free acid, I add to
it when cold as much caustic soda, potash, or lime, or hydrasulphate of soda,
potash, or ammonia as will decompose it. The alkaline or earthy base com-
bines with the hydrochloric acid, causing the solution to become one of
neutral salt, while the protoxide of manganese being precipitated from com-
bination, falls down either as such, or, when the precipitating base is conjoined
with sulphuretted hydrogen, as hydrated sulphuret of manganese. So soon as
the liquor has become clear I separate and wash the sediment, and finally
spread it out to the air to pass into the condition of hydrated sesquioxide, a
transformation which I sometimes hasten by mixing it while in a creamy state
with dry sawdust or other porous material, and which I judge to be complete
when by longer exposure its dark brown color acquires no deeper shade. The
transformation of the precipitate might be, if it were thought desirable;

page_text: perfected, or the oxidation even carried further, in a space of time inappreciably
short, by using chlorine to decompose water in which it may exist at the
moment after its formation, for which purpose the chlorine might be either
dissolved in the water or added to it in combination with the precipitating
base. By the agency of chlorine the protoxide of manganese precipitated as
berein-after described also may be converted into sesquioxide or other higher
oxide, but the saving of time would in no case compensate for the expenditure
of material by which it was effected, and there is no sufficient inducement for
carrying the oxidation of the manganese beyond a sesquioxide, for the first
revivification would return it only to that condition. When sulphate of pro-
toxide of manganese can be obtained as a residuary product of any manu-
facture, it may be substituted for the hydrochlorate in the above process; but
in that case, if the precipitant used be lime, a sulphate of that earth will fall
with the precipitate, and have to be collected and put in the purifiers
with it.
Another way of making revivifiable bydrated sesquioxide of manganese is by
further oxidising the protoxide precipitated from hydrated carbonate of man-
ganese. To use such carbonate of manganese for this purpose, I stir it into a
rather dilute solution either of caustic soda or potash, or of a hydrasulphate of
either of these alkalies, or even of a carbonated fixed alkali, provided only that
it be other than a bicarbonate; either of these decomposing reagents, if used
in sufficient quantity, will take all the carbonic acid from the protoxide of
manganese, and enable it after being freed from adhering, soluble matters to pass
readily into revivifiable bydrated sesquioxide upon being duly exposed to the
atmosphere. The protoxide may also be precipitated from its carbonic acid by
mixing with the hydrated carbonate of manganese about half its weight of
quicklime previously slaked, the mixture being damped with water; in which
case the carbonate of lime and the protoxide of manganese, both resulting from
the operation, will have to be exposed to the air together, and the products
afterwards put into the purifiers without separation. In one or other of these
ways I turn to profitable account even the carbonate of manganese, which
sometimes occurs as a refuse in the partial purification of gas, or in acting
upon gas liquor by hydrochlorate of manganese, notwithstanding the impurities
with which it is associated.
Besides these processes for making bydrated sesquioxide of manganese,
there is another, described in the Specification annexed to my Patent bearing
date the First of December 1858. I have found that the oxide made by any of
the said processes has the property of undergoing revivification on mere
exposure to the air after being used for the purification of gas, that property

page_text: being dependant on the fact that the bydrated sulphuret of manganese formed
in gas purifiers is decomposible, like hydrated sulphuret of manganese from
other sources, by atmospheric oxygen.
The revivifiable artificial oxide, and also the mixtures of native oxide with
lime or chalk, should be used in a moist condition, in dry lime purifiers, and
they may be revivified by exposure to the air in any of the ways known to
be useful in the case of hydrated peroxide of iron. Either of them may be
mixed for use with sawdust or other porous material to make it readily
permeable to air and gas, and if not so mixed in the process of manufacture,
the admixture may be made afterwards as it is required. When the artificial
oxide of manganese has to be mixed subsequently to its sesqui-oxidation, I
proceed as follows:-I take equal measures of it and of dry sawdust; I make
the sawdust wet; I spread it on the floor, and throw over it little by little the
dry sesquioxide previously reduced to fine powder, well incorporating the whole
together by rakes and shovels, adding water if necessary.
In using the oxides and mixtures of oxides herein-before described, I do not
restrict myself to their application to gas already in part purified from sul-
phuretted hydrogen by other means, but I use them also upon gas under
any circumstances in which it is ordinarily submitted to purification from
sulphuretted hydrogen.
For small gasworks in which the ammoniacal residues are thought unworthy
of attention, I charge the ordinary dry lime purifiers with the porous mixture
last described, the wetting of the sawdust, as well as all subsequent dampings
that may be found requisite, being done with a solution of hydrochlorate of
manganese or of lime. Such a mixture purifies the gas from sulphuretted
hydrogen and ammonia, and in great part also from carbonic acid, and after
use may be revivified for a repetition of that threefold purification by being
simply exposed to the air for a day or two heaped up in a warm place. It
should be always put into the purifiers moist, the oxide or the hydrochlorate
being from time to time added to the mass, as the due proportion of either is
found to be deficient, the sesquioxide being added when the mixture falls short
in purifying power for sulphuretted hydrogen, and the hydrochlorate when the
purifying power fails for carbonic acid and ammonia.
Having thus described the nature of my Invention, and how it is to be
performed, I will now define the claims made with respect to it. I claim,―
Firstly, the combined use of three or more consecutive scrubbers for the
partial purification of gas whenever they are so fitted and worked as to scrub
it finally with a small and intermitting supply of fresh water after the same
portion of gas has been consecutively scrubbed in each of two scrubbers with

page_text: water that has been gradually becoming by such use converted into ammoniacal
washings, the said washings being supplied for the purpose incessantly and in
profusion, mixed or not with condensed gas liquor, or preceded or not by the
application of such liquor to the gas in a separate preliminary scrubber;
but I do not claim the use of any scrubbers when otherwise worked for
scrubbing gas with water and ammoniacal liquor, whether together or
separately.
Secondly, the purification of gas from sulphuretted bydrogen, either wholly
or or in part, by any oxide of manganese made by raising by exposure to atmo-
spheric oxygen, any hydrated precipitate containing that metal to a state of
oxidation higher than protoxide, when the said oxide is continually re-
produced by the spontaneous revivification of the spent material; but I do not
claim the purification of gas by the higher oxides of manganese obtained by
precipitation from combinations wherein they exist as such.
Thirdly, the several processes herein-before detailed for making a higher
revivifiable oxide of manganese, subsequently to the precipitation of the
metallic preparation.
Fourthly, the purification of gas from sulphuretted bydrogen, either wholly
or in part, by mixtures compounded of caustic lime, or of chalk with native
peroxides or sesquioxides of iron or manganese; but I do not claim the puri-
fication of gas by any native oxides of iron or manganese, nor its revivification,
when unmixed with caustic lime or chalk.
Fifthly, the purification of gas by any porous mixture of an artificial and
higher oxide of manganese with hydrochlorate of the same base or of lime, in
connexion with the spontaneous reproduction of its purifying energy by the
means described.
In witness whereof, I, the said Richard Laming, have hereunto set my
hand and seal, this Seventeenth day of December, in the year of our
Lord One thousand eight hundred and fifty-nine.
Witness,
CHARLES SMITH,
8, Gloster Street,
Regent's Park.
RICHARD LAMING. (L.S.)