IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF GAS AND APPARATUS THEREFOR
Year: 1882

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, .Lake
& Co Patent Agents, Southampton Buildings, London, for an invention of
"IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF GAS AND
APPARATUS THEREFOR A communication from abroad by Thomas Burke
Fogarty, of Brooklyn, New York, United States of America,
"
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 28th February 1882.
WILLIAM ROBERT LAKE of the firm of Haseltine, Lake, & Co Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN AND RELATING TO THE
MANUFACTURE OF GAS AND APPARATUS THEREFOR." [A communication from
abroad by Thomas Burke Fogarty, of Brooklyn, New York, United States of
America.]
My invention relates to the manufacture of heating and illuminating gas through
the decomposition of steam by incandescent carbon, and to apparatus used in such
manufacture.
It is well known that nearly all of the gas obtained through the decomposition
of steam by incandescent carbon (commonly known as "water gas" by which
name I shall speak of it in this Specification) by the processes heretofore employed
is largely contaminated by carbonic oxide, a compound of such a poisonous
character, that the sale of gas containing it, except within prescribed quantities,
is in many places prohibited by law, while at the same time, much of it contains
so large a quantity of nitrogen, that its value as a heating or illuminating agent is
thereby seriously diminished.
The chief object of my invention is to produce a water-gas which within desired
limits will be free from the above mentioned impurities and which can be manu-
factured at a greatly reduced cost.
I shall now proceed to describe my invention, and for this purpose shall divide
or classify the process into and under five different parts or sub-processes, as
follows:-
1st. The manufacture of a very cheap, but exceedingly impure heating gas, the

page_text: chief impurities of which will consist of nitrogen, carbonic oxide, and carbonic
acid.
2nd. The partial purification of this gas by the conversion of its nitrogen, either
wholly or partly, into ammonia or ammoniacal salts, and the separation of these
ammoniacal products from the gas.
3rd. The further purification of the gas by the conversion, either wholly or
partly, of its carbonic oxide into carbonic acid, with the liberation of a volume of
hydrogen equal to that of the carbonic oxide removed.
4th. The practically complete purification of the gas by the removal of its
carbonic acid and sulphuretted hydrogen, such purification being chiefly effected
by means of the aminonia produced from the nitrogen of the gas itself in the
second sub-process above mentioned.
5th. The conversion, by means hereinafter described, of the ammonia and
carbonic acid of the gas into carbonates and other commercial salts.
It is to be herein understood, that, when I speak of purification, I do not mean
that I shall render the gas absolutely free from the impurity to which I may refer,
but merely that I shall render it practically and reasonably free from such
impurity.
It is also to be understood that when I speak of removing any impurity or other
matter from the gas, I refer to its removal to a practical and reasonable degree.
I shall now proceed to describe in detail the several parts or sub-processes
constituting my complete process, their connection with each other, through the
apparatus which may be employed, and the manner of their combination to forin
one perfect and continuous process.
In carrying out the first part or sub-process, I admit steam into a close cupola
furnace, or retort of any suitable form or construction, filled, or partly filled, with
incandescent carbon, such as coal, coke, charcoal, or peat, and heated by an external
fire or by internal combustion, or by a combination of both; and, in conjunction
with such steam, and by means of any suitable pump, jet, aspirator or exhauster,
I either draw or force into and through the said cupola furnace, or retort, a
suitable volume of atmospheric air.
When the cupola furnace, or retort, is hented externally, either wholly or partly,
the volume of air admitted may be regulated according to the percentage of
nitrogen which it is desirable that the gas should contain at this time; but when
it is heated by internal combustion, as will usually be found the preferable course,
the volume of air admitted must bear such a proportion to the volume of steam:
and the requirements of the combustion taking place within the cupola, that the
oxygen contained in such air will be capable of supporting the combustion
sufficiently to overcome and counteract the cooling effect of the decomposition of
the steam, in which case the temperature of the cupola or furnace will be even and
uniform, proper provision being made for feeding and cleaning the fire. The
steam and air upon the one hand, and the fuel upon the other, will now.combine
with each other to form a highly combustible gas, which will vary in composition
according to the temperature of the furnace or cupola, the relative proportions of
the steam and air, and the greater or less thickness of the stratum of incandescent
carbon through which it has passed; but, under suitable conditions the gas
produced will have an average composition about as follows:-
Carbonic acid
-
10 per cent.
Carbonic oxide-
Hydrogen
Nitrogen
17
"
"
13
"
"
60
77
"
It is evident that by keeping the proportions of air and steam perfectly adjusted
to each other, the furnace or cupola may be kept at a uniform temperature, and
the production of gas may be made continuous.
"
The gas produced in this manner is really what is known as a "generator gas,"
and while capable of being used to advantage for heating purposes, it is of little

page_text: practical use for lighting. But part of the gas so produced may be made the
basis of an excellent illuminating gas and another portion advantageously used as
fuel to heat the retorts and other apparatus to be hereinafter described.
The second part or sub-process refers to the removal of the nitrogen, either
wholly or partly from the gas by its conversion either wholly or partly into
ammonia or some of the salts thereof.
For the purpose of removing the nitrogen, I now cause the gas to pass through
a retort or chamber, or series of such, containing coal, coke, charcoal, or other
suitable form of carbon, in a highly incandescent state, and mixed in suitable
proportions with an alkali of some sort, such as soda, potash, lime, barium, or any
suitable mixture, compound or combination of the same; but preferably I use the
carbonate of an alkali which parts readily with its acid.
Now under the influence of the intense temperature, the carbon, nitrogen, and
alkali will combine to form cyanide and cyanate of the alkali used, and these
being brought into contact with steam at a suitable temperature, are decomposed
by it and give rise to ammonia or ammoniacal compounds formed by the
combination of the nitrogen of the cyanides and cyanates with the hydrogen of
the steam, the liberated carbon uniting with the oxygen of the steam to form
additional volumes of carbonic oxide and carbonic acid, and the alkali returning to
its original state, or entering into fresh combinations.
It is well known that ammoniacal gas and many ammonia compounds are
decomposed by a red heat, while other compounds (notably muriate of ammonia)
are merely volatilized at the same temperature, and this circumstance would
present an insuperable obstacle to the employment of some alkaline compounds
(notably the alkaline carbonates) for the purposes of my Invention, were it not
that the cyanides and cyanates of the alkalies are decomposed by steam at a
temperature much less than that which is required to produce them. From this it
follows that, in order to prevent the destruction of ammonia, or such of its
compounds as are decomposed by a red heat, it is only necessary to see that, as far
as possible, the temperature at which they are formed, shall be below a decomposing
heat.
As it is evident that ammonia cannot be formed except in inconsiderable
quantities owing to the presence of but little moisture in the gas, unless steam be
admitted to the retort, it is frequently necessary to arrange the retort so as to be
beated by a separate fire at each end, or iu some other way, so that each end of
it may be kept at a suitable temperature. The steam being then admitted only
in the cooler end of the retort, the resulting ammoniacal products will be in no
danger of being destroyed by excessive temperature.
For the same reason it is often advisable to effect the decomposition of the
cyanogen compounds, and the subsequent conversion of their nitrogen into ammonia,
in a retort or chamber, or series of such, separate from that in which they have
been formed, and kept at a lower temperature.
It may also be often expedient to effect or cause the formation of the ammoniacal
compounds in the same retort or furnace in which the "generator gas" is produced
in the first sub-process above described. In this case it will be necessary to apply
external heat to the generator furnace and to lengthen or extend it, or otherwise
provide a suitable chamber in which the cyanogen compounds formed within the
furnace may be reduced to a temperature suitable for the production and
preservation of the ammoniacal products. In this case the alkali may be intro-
duced directly into the generator, which may be done by mixing it with the coal
in a mass, or in alternate layers, or by spraying or injecting it therein, as may be
most convenient.
When the alkali used is chloride of sodium, it is not necessary to reduce the
temperature of the cyanogen compounds, as the product of their decomposition
will in this case be chloride of ammonium which, instead of being decomposed, is
only volatilized at elevated temperatures.
In any case, care must be taken that the cyanogen compounds be formed at the

page_text: temperature best suited to their economical production, and that the subsequent
ammoniacal products, also be formed at the temperature best adapted to their
preservation.
The gas, now consisting principally of hydrogen, ammonia in different forms,
carbonic oxide, carbonic acid and such nitrogen as may have escaped decomposition
and conversion, is next passed through a suitably constructed condenser, or
scrubber, or other cooling apparatus so as to reduce its temperature sufficiently to
admit of the combination of the ammonia and carbonic acid which always takes
place when these gases are brought together at a low temperature. The resulting
carbonates of ammonia are very soluble in water, and may be absorbed and
separated by it in passing through the scrubber or condenser, or, if desired, in a
separate apparatus.
A little reflection will now shew why I prefer to use the alkali in the form of a
carbonate. By doing so, the resulting ammonia will be obtained, for the most
part in a free or uncombined state, and will consequently be in the best possible
form for use as an effective means of removing the enormous quantities of carbonic
acid which would otherwise require to be removed by absorption by lime or by
some other equally expensive and laborious operation.
I shall now proceed to describe in detail the third part or sub-process, which
relates to the further purification of the gas by the conversion, either wholly or
partly, of its carbonic oxide into carbonic acid, with the liberation of a volume of
hydrogen equal to that of the carbonic oxide removed.
The gaseous products being freed from ammonia, and consisting principally of
hydrogen, carbonic oxide, carbonic acid and such nitrogen as may have escaped
conversion, are now caused to pass through one or more lightly heated retorts in
which they are brought into intimate contact with steam, when all being brought
to an intense heat, the steam is decomposed by the carbon of the carbonic oxide,
giving rise to a volume of carbonic acid equal to that of the decomposed oxide, and
at the same time setting an equal quantity of hydrogen free.
The fourth part or sub-process relates to purifying the gas from carbonic acid
and sulphuretted hydrogen.
In the manufacture of water gas as heretofore practised, it has been found
impracticable, with one notable exception, to remove from it the carbonic oxide
which is always generated in large quantities when steam is decomposed by
incandescent carbon; the only practical process of removing it yet discovered being
to convert it into carbonic acid, as is done in the preceding sub-process; but such
method has heretofore been found to necessitate too much subsequent labour and
expense, because it became necessary to remove an enormous quantity of carbonic
acid thereby produced, the only practical method of doing which was to absorb the
carbonic acid by means of hydrate of lime, a method so expensive and laborious on
the scale required that it has been abandoned, and the manufacturers of water gas,
finding it much cheaper and handier to do so, have in practice turned their
attention to producing as much carbonic oxide with as little carbonic acid as
possible; and this, notwithstanding the fact, that there are several other well
known processes for converting the former into the latter gas; the great expense
of these processes however prevents their use.
My practice is the contrary of this, inasmuch as I convert all, or nearly all, the
carbonic oxide into carbonic acid, and then remove the latter impurity as will be
presently seen with little labor, and almost without expensc.
It is well known that large quantities of ammoniacal products are obtained in
the process of manufacturing illuminating gas from bituminous coal, and that,
consequently, coal-gas engineers have taken advantage of the affinity of ammonia
for carbonic acid, and are now commonly using it as an effective and inexpensive
means of removing the latter impurity from the gas. In the manufacture of
water-gas, however, as heretofore conducted, the quantity of ammonia produced is
relatively small as compared with that obtained in making coal gas while the
percentage of carbonic acid is many times greater, consequently the manufacturers

page_text: of water-gas have hitherto been unable to avail themselves of ammonia as a
purifying agent. But, through the large amount of ammonia and other valuable
commercial products obtained by my improved process, I become possessed of
purifying agents which involve but little labor and expense, and which morcover
leave me in the end valuble residua for which there is a constant and increasing
demand.
It is quite obvious therefore that my process may be also very readily used, in
combination therewith, or as an adjunct thereto, in the ordinary process of
manufacturing gas from bituminous coal, as the alkali, air, and steam may be
introduced, in any of the forms or by any of the means herein explained for the
generation and purification of the "water gas" into suitable coal retorts as soon as
the coal therein shall be sufficiently converted into coke. In such case the cupola
used in the first sub-process herein described can be dispensed with, and the first
and second sub-process may be carried on or conducted in the same retort or series
of retorts (very much as herein described for the "water-gas" proper) the more
volatile gases having been expelled from the bituminous coal in the said retorts
previous to the introduction therein of the alkali, air, and steam upon the remaining
mass of devolatilized carbon or coke as just stated.
For the purpose, therefore, of purifying the gas from the enormous quantity of
carbonic acid which at this stage of the process it contains, I avail myself of the
great quantity of ammonia resulting from the decomposition of the nitrogen in the
second sub-process herein before described; and by means of scrubbers, or other
suitable devices, and under suitable conditions of moisture and temperature, I bring
the ammonia into intimate contact with the carbonic acid and sulphuretted
hydrogen of the gas, and cause it to combine therewith so as to form commercial
salts, which are readily separated and collected. In reference to the second sub-
process, however, I have herein before described the practically complete removal
of the ammonia from the gas at that time, by its combination with the carbonic
acid and sulphuretted hydrogen of the gas and the removal of the commercial
salts thereby formed. I have therefore found it advantageous to remove the
ainmoniacal products from the gas previous to its purification from carbonic oxide,
so as to preserve them from being decomposed by the intense heat to which the
gas is subjected in decomposing the carbonic oxide into carbonic acid gas.
In order then to avail myself of this ammonia for the removal of the carbonic
acid produced as herein before described from the decomposition of the carbonic
oxide in contact with highly heated steam, I recover or regenerate the ammonia by
any suitable process, but I preferably use a modification of what is known as the
ammonia-soda process, as will be shown more fully in the next part of this
specification. which relates to the fifth part of my process, and the ammonia so
recovered or regenerated I use for the removal of fresh equivalents of carbonic
acid, just as used in the second sub-process; and this regeneration and removal I
repeat as often as necessary for the complete purification of the gas from carbonic
acid, and from all impurities capable of being removed by ammonia.
I shall now proceed to describe the fifth part of my invention which relates to
the recovery or regeneration of the ammonia in the gas and the simultaneous
production of valuable commercial salts.
Having already described the process of causing the ammonia and carbonic acid
to combine and form soluble carbonates of ammonia, it is unnecessary to do more
than allude to it here; but, in order to facilitate subsequent operations, it is
advisable, as far as possible, to concentrate the ammoniacal solutions so formed, and
for this purpose they are pumped repeatedly through the scrubbers until they
attain the desired degree of concentration. The aminoniacal solution having thus
attained the desired strength, the next step is to introduce it into a properly
constructed vessel or chamber, or series of vessels or chambers, in which an
equivalent of chloride of sodium is added to it. The liquid is now kept in agitation
for some time by means of stirrers or agitators, or by being continually pumped
through narrow circuitous or winding chambers or channels until a doublo

page_text: decomposition takes place with the production of chloride of ammonium and
carbonates of soda.
If care be taken to have a sufficient excess of carbonic acid present, the soda
salts formed will be chiefly in the form of the bi-carbonate which is only slightly
soluble and may be readly separated from the mother liquor by a centrifugal
machine or by filtering. The chloride of ammonium will remain in solution in the
mother liquor and may be crystallized out, or if it be desired to recover the ammonia
in a gaseous form for the purpose of repeating the operation of causing it to absorb
fresh equivalents of carbonic acid, the mother liquor may be heated in a boiler
with a quantity of slaked lime, preferably slightly in excess of the chloride of
ammonium present, with the formation of water, chloride of lime, and ammoniacal
gas.
The chloride of lime will be found dissolved in the water and may be made
available as a disinfectant, while the ammoniacal gas may be used for the removal of
further equivalents of carbonic acid.
The gas at this stage of the process consists chiefly of pure hydrogen, and being
practically free from all poisonous or otherwise noxious impurities, is eminently
fitted to be used as a heating gas, either for domestic or manufacturing purposes,
while it is equally capable of being carburetted by any of the usual and well known
processes and of being thus converted into an illuminating gas of a high standard,
practically free from impurities. At the same time, there may yet cling to it a
small per centage of sulphurous impurities which are incapable of being removed
by ammonia, and which may require for their complete removal other means of
purification; under which circumstances, the ordinary iron or lime purification will
be quite sufficient, and will be found inexpensive on account of the extremely
small amount of impurities which are present.
By the above described process I am enabled to produce a nearly pure hydrogen
gas at a very slight cost, and in addition will have, in the enormous quantity of
ammonia and soda salts produced, valuable residua, the sale of which will, under
favorable circumstance, more than pay the cost, not only of producing, but also of
carburetting and distributing the said gas.
The following is a description of apparatus suitable for conducting my process
that is to say I provide a cupola or furnace of any suitable construction having an
ash-pit door, a chimney provided with a suitable cap or valve, a hopper for feeding the
furnace, a steam pipe and air pipe both provided with suitable cocks or valves and
a steam jet or injector at the end of the steam pipe which is connected by means
of the said pipe with a suitable boiler. This cupola or furnace is connected by
means of a pipe to a retort set in a suitable furnace, the said pipe forming the
inlet to the said retort and being provided with a branch pipe. The outlet of this
retort is connected with a pipe leading to a scrubber. This scrubber is of any
suitable construction and is provided with inlet and outlet pipes, a water pipe, and
an overflow It is connected by means of another pipe to a furnace of any suitable
construction, containing a retort, The said retort has a suitable outlet connected
to another scrubber and is also provided with a steam-pipe suitably connected to
a steam-boiler. The second scrubber is provided with an outlet, a water pipe, and
an overflow.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
28th August 1882.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN AND RELATING TO THE
MANUFACTURE OF OAS AND APPARATUS THEREFOR A communication from
abroad by Thomas Burke Fogarty, of Brooklyn, New York, United States of
America.
This Invention relates to the manufacture of heating and illuminating gas
through the decomposition of steam by incandescent carbon and to apparatus to
be used in such manufacture.
It is well known that nearly all of the gas obtained through the decomposition
of steam by incandescent carbon (commonly known as "water gas" by which
name I shall speak of it in this specification) by the processes heretofore employed,
is largely contaminated by carbonic oxide, a compound of such a poisonous
character, that the sale of gas containing it, except within prescribed quantities is
in many places prohibited by law, while, at the same time, much of it contains so
large a quantity of nitrogen, that its value as a heating or illuminating agent is
thereby seriously diminished.
The chief object of the said Invention is to produce a water-gas, which within
desired limits, will be free from the above mentioned impurities and which can be
manufactured at a greatly reduced cost.
I shall now proceed to describe the said Invention so fully and clearly that any
person skilled in the art of making “ water-gas” may be able to understand and
practice the process, and, for this purpose, I shall divide or classify the said process
into and under five different parts or sub-processes, as follows;
First. The manufacture of a very cheap but exceedingly impure heating gas,
the chief impurities of which will consist of nitrogen, carbonic oxide and carbonic
acid.
Second. The partial purification of this gas by the conversion of its nitrogen,
either wholly or partly, into ammonia or ammoniacal salts, and the separation of
these ammoniacal products from the gas.
Third. The further purification of the gas by the conversion, either wholly or
partly, of its carbonic oxide into carbonic acid, with the liberation of a volume of
hydrogen equal to that of the carbonic oxide removed.
Fourth. The practically complete purification of the gas by the removal of its
carbonic acid and sulphuretted hydrogen, such purification being chiefly effected by
means of the ammonia produced from the nitrogen of the gas itself in the second
sub-process above mentioned.
Fifth. The conversion, by means hereinafter described, of the ammonia and
carbonic acid of the gas into carbonates and other commercial salts.
It is to be herein understood that, when I speak of purification, I do not
mean that I shall render the gas absolutely free from the impurity to which I may
refer, but merely that I shall render it practically and reasonably free from
such impurity.
It is also to be understood that when I speak of removing any impurity or
other matter from the gas, I refer to its removal to a practical and reasonable
degree.
I shall now proceed to describe in detail the several parts or sub-processes
constituting my complete process, their connection with each other, through the

page_text: apparatus which may be employed, and the manner of their combination to form
one perfect and continuous process.
In carrying out the first part or sub-process I admit steam into a close cupola,
furnace, or retort, of any suitable form or construction, filled or partly filled with
incandescent carbon, such as coal, coke, charcoal or peat, and heated by an external
fire or by internal combustion, or by a combination of both; and, in conjunction
with such steam, and by means of any suitable pump, jet, aspirator, or exhauster,
I either draw or force into and through the said cupola, furnace, or retort, a suitable
volume of atmospheric air.
When the cupola, furnace, or retort, is heated externally, either wholly or partly,
the volume of air admitted may be regulated according to the percentage of
nitrogen which it is desirable that the gas should contain at this time; but when
it is heated by internal combustion, as will usually be found the preferable course,
the volume of air admitted must bear such a proportion to the volume of steam and
the requirements of the combustion taking place within the cupola, that the
oxygen contained in such air will be capable of supporting the combustion
sufficiently to overcome and counteract the cooling effect of the decomposition of
the steam, in which case the temperature of the cupola or furnace will be even and
uniform, proper provision being made for feeding and cleaning the fire. The steam
and air upon the one hand and the fuel upon the other hand will now combine
with each other to form a highly combustible gas which will vary in composition
according to the temperature of the furnace or cupola, the relative proportions of
the steam and air, and the greater or less thickness of the stratum of incandescent
carbon through which it has passed; but, under suitable conditions, the gas
produced will have an average composition about as follows:-
Cashanie id

page_text: are merely volatilized at the same temperature, and this circumstance would present
an insuperable obstacle to the employment of some alkaline compounds (notably
the alkaline carbonates) for the purposes of the said invention, were it not that
the cyanides and cyanates of the alkalies are decomposed by steam at a temperature
much less than that which is required to produce them. From this it follows that,
in order to prevent the destruction of ammonia or such of its compounds as are.
decomposed by a red heat it is only necessary to see that, as far as possible, the
temperaturo at which they are formed shall be below a decomposing heat.
As it is evident that ammonia cannot be formed, except in inconsiderable
quantities, owing to the presence of but little moisture in the gas, unless steam be
admitted to the retort, it is frequently necessary to arrange the retort so as to be
heated by a separate fire at each end, or in some other way, so that each end of it
may be kept at a suitable temperature. The steam being then admitted only in
the cooler end of the retort, the resulting ammoniacal products will be in no
danger of being destroyed by excessive temperature.
For the same reason it is often advisable to effect the decomposition of the
cyanogen compounds, and the subsequent conversion of their nitrogen into
ammonia in a retort or chamber, or series of such, separate from that in which
they have been formed, and kept at a lower temperature.
It may also be often expedient to effect or cause the formation of the
ammoniacal compounds in the same retort or furnace in which the "generator
gas" is produced in the first sub-process above described. In this case it will be
necessary to apply external heat to the generator furnace and to lengthen or extend
it, or otherwise provide a suitable chamber in which the cyanogen compounds
formed within the furnace may be reduced to a temperature suitable for the
production and preservation of the ammoniacal products. In this case the alkali
may be introduced directly into the generator, which may be done by mixing it
with the coal in a mass, or in alternate layers, or by spraying or injecting it
therein, as may be most convenient.
When the alkali used is chloride of sodium it is not necessary to reduce the
temperature of the cyanogen compounds, as the product of their decomposition will
in this case be chloride of ammonium which instead of being decomposed is only
volatilized at elevated temperatures.
In any case, care must be taken that the cyanogen compounds be formed at the
temperature best suited to their economical production, and that the subsequent
ammoniacal products, also, be formed at the temperature best adapted to their
preservation.
The gas, now consisting principally of hydrogen, ammonia in different forms,
carbonic oxide, carbonic acid and such nitrogen as inay have escaped decomposition
and conversion, is next passed through a suitable constructed condenser, or
scrubber, or other cooling apparatus, so as to reduce its temperature sufficiently to
admit of the combination of the ammonia and carbonic acid which always takes
The resulting
place when these gases are brought together at a low temperature.
carbonates of ammonia are very soluble in water, and may be absorbed and
separated by it in passing through the scrubber or condenser, or, if desired, in a
separate apparatus.
A little reflection will now show why I prefer to use the alkali in the form of a
carbonate. By doing so, the resulting aminonia will be obtained for the most part
in a free or uncombined state and will consequently be in the best possible form
for use as an effective means of removing the enormous quantities of carbonic acid
which would otherwise require to be removed by absorption by lime, or by some
other equally expensive and laborious operation.
I shall now proceed to describe in detail the third part or sub-process which
relates to the further purification of the gas by the conversion, either wholly or
partly, of its carbonic oxide into carbonic acid, with the liberation of a volume of
bydrogen equal to that of the carbonic oxide removed.
The gaseous products being freed from ammonia and consisting principally of

page_text: hydrogen, carbonic oxide, carbonic acid and such nitrogen as may have escaped
conversion and now caused to pass through one or more highly heated retorts, in
which they are brought into intimate contact with steam, when, all being brought
to an intense heat, the steam is decomposed by the carbon of the carbonic oxide,
giving rise to a volume of carbonic acid equal to that of the decomposed oxide, and,
at the same time, setting an equal quantity of hydrogen free.
The fourth part or sub-process relates to purifying the gas from carbonic acid
and sulphuretted hydrogen.
In the manufacture of water-gas as heretofore practised it has been found
impracticable, with one notable exception, to remove from it the carbonic oxide
which is always generated in large quantities when steam is decomposed by
incandescent carbon; the only practical process of removing it yet discovered being
to convert it into carbonic acid as is done in the preceding sub-process; but such
method has heretofore been found to necessitate too much subsequent labor and
expense, becauso it became necessary to remove an enormous quantity of carbonic
acid thereby produced; the only practical method of doing which was to absorb
the carbonic acid by means of hydrate of lime, a method so expensive and laborious,
on the scale required, that it has been abandoned and the manufacturers of
water-gas, finding it much cheaper and handier to do so, have in practice turned
their attention to producing as much carbonic oxide with as little carbonic acid as
possible; and this, notwithstanding the fact, that there are several other well
known processes for converting the former into the latter gas; the great expense
of these processes, however, prevents their use. My practice is the contrary of this,
inasmuch as I convert all, or nearly all, the carbonic oxide into carbonic acid and then
remove the latter impurity, as will be presently seen, with little labor and almost
without expense.
It is well known that large quantities of ammoniacal products are obtained in
the process of manufacturing illuminating gas from bituminous coal, and that,
consequently, coal-gas engineers have taken advantago of the affinity of ammonia
for carbonic acid, and are now commonly using it as an effective and inexpensive
means for removing the latter impurity from the gas. In the manufacture of
water-gas, however, as heretofore conducted, the quantity of aminonia produced is
relatively small as compared with that obtained in making coal-gas, while the
percentage of carbonic acid is many times greater, consequently the manufacturers
of water-gas have hitherto been unable to avail themselves of ammonia as a
purifying agent. But, through the large amount of ammonia and other valuablo
commercial products obtained by my improved process, I become possessed of
purifying agents which involve but little labor and expense, and which moreover
leave me in the end valuable residua for which there is a constant and increasing
demand.
It is obvious, therefore, that my process may be also very readily used, in
combination therewith or as an adjunct thereto, in the ordinary process of
manufacturing gas from bituminous coal, as the alkali, air, and steam may be
produced, in any of the forms or by any of the means herein explained for the
generation and purification of the "water-gas," into suitable coal retorts as soon as
the coal therein shall be sufficiently converted into coke. In such case, the cupola
used in the first sub-process herein described can be dispensed with and the first
and second sub-process may be carried on or conducted in the same retort, or series
of retorts (very much as herein described for the "water-gas" proper), the more
volatile gases having been expelled from the bituminous coal in the said retorts
previous to the introduction therein of the alkali, air and steam upon the remaining
mass of devolatilized carbon or coke as just stated.
For the purpose, therefore, of purifying the gas from the enormous quantity of
carbonic acid which, at this stage of the process, it contains, I avail myself of the
great quantity of ammonia resulting from the decomposition of the nitrogen in the
second sub-process hereinbefore described; and by means of scrubbers, or other
suitable devices, and under suitable conditions of moisture and temperature, I

page_text: bring the ammonia into intimate contact with the carbonic acid and sulphuretted
hydrogen of the gas, and cause it to combine therewith so as to form commercial
salts, which are readily separated and collected. In reference to the second sub-
process, however, I have herein before described the practically complete removal of
the ammonia from the gas at that time by its combination with the carbonic acid
and sulphuretted hydrogen of the gas, and the removal of the commercial salts
thereby formed. I have, therefore, found it advantageous to remove the ammoniacal
products from the gas previous to its purification from carbonic oxide so as to
preserve them from being decomposed by the intense heat to which the gas is
subjected in decomposing the carbonic oxide into carbonic acid gas.
In order then to avail myself of this ammonia for the removal of the carbonic
acid produced, as hereinbefore described, from the decomposition of the carbonic
oxide in contact with highly heated or incandescent steam, I recover or regenerate
the ammonia by any suitable process, but I preferably use a modification of what
is known as the ammonia-soda process, as will be shown more fully in the next
part of this specification which relates to the fifth part of my process, and the
ammonia so recovered or regenerated I use for the removal of fresh equivalents of
carbonic acid, just as used in the second sub process, and this regeneration and
removal I repeat as often as necessary for the complete purification of the gas
from carbonic acid and from all impurities capable of being removed by ammonia.
I shall now proceed to describe the fifth part or sub-process, which relates to
the recovery or regeneration of the ammonia in the gas, and the simultaneous
production of valuable commercial salts.
Having already described the process of causing the ammonia and carbonic acid
to combine and forin soluble carbonates of ammonia, it is unnecessary to do more
than allude to it here; but, in order to facilitate subsequent operations, it is
advisable, as far as possible, to concentrate the ammoniacal solutions so formed,
and, for this purpose, they are pumped repeatedly through the scrubbers until they
attain the desired degree of concentration. The ammoniacal solution having thus
attained the desired strength, the next step is to introduce it into a properly
constructed vessel or chamber, or series of vessels or chambers, in which an
equivalent of chloride of sodium is added to it. The liquid is now kept in agitation
for some time by means of stirrers or agitators, or by being continually pumped
through narrow circuitous or winding chambers or channels until a double
decomposition takes place with the production of chloride of ammonium and
carbonates of soda. If care be taken to have a sufficient excess of carbonic acid
present, the soda salts formed will be chiefly in the form of the bi-carbonate, which
is only slightly soluble, and may be readily separated from the mother liquor by a
centrifugal machine or by filtering. The chloride of ammonium will remain in
solution in the mother liquor and may be crystallized out, or, if it be desired to
recover the ammonia in a gaseous form for the purpose of repeating the operation
of causing it to absorb fresh equivalents of carbonic acid, the mother liquor is
heated in a boiler with a quantity of slaked lime, preferably slightly in excess of
the chloride of ammonium present, with the formation of water, chloride of lime
and ammoniacal gas.
The chloride of lime will be found dissolved in the water and may be made
available as a disinfectant, while the ammoniacal gas may be used for the removal of
further equivalents of carbonic acid.
The gas, at this stage of the process, consists chiefly of pure hydrogen, and, being
practically free from all poisonous or otherwise noxious impurities, is eminently
fitted to be used as a heating gas, either for domestic or manufacturing purposes,
while it is equally capable of being carburetted by any of the usual and well
known processes, and of being thus converted into an illuminating gas of a high
standard, practically free from impurities. At the same time, there may yet cling
to it a small percentage of sulphurous impurities which are incapable of being
removed by ammonia, and which may require for their complete removal other
means of purification; under which circumstances the ordinary iron or lime

page_text: purification will be quite sufficient and will be found inexpensive on account of
the extremely small amount of impurities which are present.
By the above described process I am enabled to produce a nearly pure hydrogen
gas at a very slight cost, and, in addition, will have, in the enormous quantity of
ammonia and soda salts produced, valuable residua, the sale of which will, under
favorable circumstances, inore than pay the cost, not only of producing, but also of
carburetting and distributing the said gas.
The accompanying drawing illustrates apparatus suitable for conducting my
process,
Figure 1 is an elevation showing a cupola or furnace A, of any suitable con-
struction, in which B is the ash-pit door, C the chimney provided with a suitable
cap or valve D, E a hopper for feeding the furnace, F a steam-pipe and G an air-
pipe, and H, a steam jet or injector connected through the pipe F with a suitable
boiler not shown in the drawing.
Figure 2 represents, in sectional elevation, a retort K. set in a suitable furnace
and shown as being partly filled, and heated by two fires L and M. Its inlet N,
is shown as connected to the cupola A (Figure 1) by the pipe I, while its outlet is
connected with the pipe P.
Figure 3 shows, in elevation, a scrubber X, of any suitable construction, pro-
vided with an inlet-pipe Q, an outlet pipe R, a water-pipe S, and an overflow T.
Figure 4 shows an elevation, partly in section, of a furnace U, of any suitable
construction, containing a retort V, having its inlet W, connected to the scrubber X
by the pipe R, and having a suitable outlet Y. It is also provided with a
steain-pipe a suitably connected to a steam boiler not shown in the Drawing.
Figure 5 shows, in elevation, a scrubber b which is attached to the outlet Y of
the retort V (Figure 4) by the inlet C2, and is provided with an outlet-pipo d, a
water pipe c, and an overflow f.
The mode of operation is as follows, that is to say :-I first open the door B and
chimney valve D of the furnace or cupola A (Figure 1) and, having filled the
furnace to a suitable depth with coal, coke, charcoal or other suitable form of
carbon, I ignite the fuel, and allow it to burn until it becomes incandescent, at
least to a considerable degree. When the fuel in the furnace has attained a proper
working heat, I close the valve D, and having opened the cock of the steam-pipe F,
which is supplied with steam from a suitable boiler not shown in the Drawing,
and also opened the cock on the air-pipe G to the atmosphere, the steam is blown
through the jet H carrying with it or inducing a current of air, drawn through
the open air-pipe G, and forcing it into the ash pit beneath the furnace.
As soon
as the current of mingled air and steam strikes the incandescent fuel in the cupola,
the steam becomes decomposed with a slight explosion, and flame issues from the
door B. The pipe c, on the pipe I, is now opened, and the door B, tightly closed,
whereupon the mingled current of steam and air is forced upward through the mass
of incandescent fuel in the cupola, from which they escape through the outlet at I¹,
as an impure "generator gas," the hydrogen of the steain and the nitrogen of the
uir passing unchanged while their oxygen combines with the carbon of the coal
or other fuel, to produce carbonic oxide, and carbonic acid, in proportions which
will vary according to the relative volumes of the steam and air the temperature
of the furnace and the depth of incandescent fuel in it.
The production of gas will now be uniform and continuous, if proper care be
taken to replenish and clean the fire at proper intervals. Its quality too will be
tolerably constant and uniform, if the relative volumes of air and steam are
properly adjusted.
Under favorable conditions, the average composition of the escaping gas will be
about as follows:-

page_text: The "generator gas" escaping from the cupola A, now enters the retort K
(Figure 2) by the inlet N, the pipe c having been closed. This retort is shown
in the drawing as being heated by a separate fire at each end so as to afford means
for keeping each end at the temperature best suited to the work it has to do. It
is evident, however, that the same effects can be produced, by means of two, or
even a series of retorts set in one or more suitable arranged furnaces.
It may, however, be found desirable and of more or less importance, before
passing the gas into the retort K, to pass it through a condenser or other cooling
or drying chamber, in order to remove from the gas any steam that may remain
undecomposed after leaving the fnrnace or cupola A.
The retort K is filled at one end, as shown in the Drawing, with coal, coke,
charcoal, or other suitable form of carbon, suitably mixed with an alkali, or some
suitable form, compound, or combination of an alkali, and at the other end or at
any suitable or convenient point the said retort is furnished with the pipe h
supplied with steam from any suitable source. Care must be taken that the end
of the retort which contains the mixed carbon and alkali is kept at a high
temperature, and the other end comparatively cool, so that the highly heated gases
escaping from the incandescent mass of carbon and alkali may be reduced to a
suitable temperature by the comparatively low heat of the retort itself as well as
by the cooling effect of a volume of steam which is admitted to it through the
pipe h.
As the gas passes through the incandescent mass of carbon and alkali at one
end of the retort K, its nitrogen unites with them to form cyanide and cyanate of
the alkali, and these escaping from the incandescent inass and being brought into
suitable contact with steam at a suitable temperature in the other end of the
said retort, mutual decomposition and transposition of their elements ensue, the
nitrogen combining with the hydrogen of the steam to form ammonia, and the
carbon going to the oxygen to form carbonic oxide and carbonic acid, while the
alkali returns to its original condition or unites with the carbonic acid to form a
carbonate.
From the retort K the gas, freed as far as desirable from nitrogen, now passes
through the outlet O, and connecting pipe P, to the scrubber X (Figure 3) through
which it passes slowly, and in which it is continually broken up by and brought
into contact with the cool, wet surfaces of coke, brush, slats or other substances
capable of obstructing and breaking it up, with which the scrubber is filled, and
over which water or other liquid is caused to trickle slowly. The consequence of
this scrubbing process is that the gas attains a low temperature, and the ammonia
taking up its equivalent of carbonic acid is converted into a carbonate, which is
immediately dissolved by the liquid passing through the scrubber, and is carried
off by it through the overflow T, and collected in any suitable vessel or vessels.
The gas, which is now reasonably free from nitrogen, escaping from the scrubber
through the pipe R, enters the retort V (Figure 4) at W where it meets with a
current of steam, preferably superheated, supplied from a suitable boiler through
the pipe a, and immediately decomposes the said steam, the oxygen of the steam
combining with the carbonic oxide of the gas, and converting it into carbonic
acid, while its hydrogen is set free, and goes to swell the volume of the combustible
gases.
The volumes of carbonic acid and hydrogen resulting from the decomposition of
the steam by the carbonic oxide, will be, in all cases, each equal to the entire
volume of carbonic oxide removed from the gas.
The gas now requires to be freed from the enormous volume of carbonic acid
which it contains, and this I effect by causing it to pass from the retort V (Figure 4)
through the connecting pipe Y into the scrubber b (Figure 5) which it enters at c²
and in which it meets with a volume of ammonia, which, meanwhile having been
regenerated or recovered as before explained, is caused to enter the scrubber b
through any suitable connection which may be made thereto, and which is not
shown in the Drawing.

page_text: The gas now passes slowly upward through the scrubber b, mingled with the
regenerated ammonia, and both cases being thoroughly mixed and broken up by
the obstructions which they meet with, and being, moreover, subjected to suitable
cooling influences and to the contact of wet surfaces, the ammonia again takes up
its equivalent of carbonic acid, the resulting carbonates being dissolved in the
liquid and passing off through the overflow f of the scrubber.
As the volume of carbonic acid in the gas, when it leaves the retort V, is usually
much more than the equivalent of the regenerated ammonia, it is mostly necessary
to regenerate the latter more than once before it can be made available for the
complete removal of the carbonic acid.
The gas is now in a condition to be next treated either as a heating or illu-
minating agent. For the former purpose, it is only necessary to distribute it to,
and consume it in, suitable burners or other apparatus but, for the latter purpose,
it still requires to be suitably carburetted, or enriched with carbon or hydrocarbon
gases or vapors, before it becomes capable of being used for the ordinary purposes
of illumination. As, however, there are various well known processes for this
purpose, and as, moreover, such processes have no necessary connection with the
said invention but are merely incidental thereto, it in unnecessary here to do more
than allude to them.
The ammonia having now done its work as a purifying agent, I next proceed to
collect and transform it into a commercial product, and for this purpose I employ
a well known process preferably the ammonia-soda process herein before described,
thereby obtaining after the ammonia has finally performed its office as a grand
purifying agent, large quantities of commercial and very valuable ammonia salts.
I do not bind or confine myself strictly to the special sub-processes, or to the
exact succession of the same, or to the special forms of the apparatus above
described, for it is very evident that in a continuous and extended process like
mine, the several sub-processes and details, and the exact order and succession of
the same, as well as the forms, construction and arrangement of the apparatus used
for such process as a whole may be greatly varied, without departing from the
nature of the said invention.
Moreover I do not confine or restrict myself to the particular state, form, or
combination in which the carbon and alkali are introduced into the retort, for it is
well known that, under suitable conditions, the carbon of the carbonic oxide
contained in the gas may be made available for this purpose; and indeed it is
more than probable that this carbon, under any circumstances, takes its part in
the chemical reactions and mutual decompositions which take place within the
retort. Nor do I confine or restrict myself to the particular form or arrangement
of the retort and furnace shewn, as it is evident that this may be greatly varied,
their forins and relative arrangement and connection, the manner of using them,
and the order and arrangement of the chemical changes and reactions which take
place within them vary according to the nature and form of the alkali used, and
of the products desired.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent and the manner of performing the same I wish it understood
that I do not claim the process of converting nitrogen into ammonia by means of
an alkali, except as applied for the removal, either wholly or partly, of the free
nitrogen from a heating or "generator gas" such as that generated in the first
sub-process above described. Nor do I claim the process of placing lime or other
alkali in a retort with the coal or other carbon during the process of distilling it
for the production of gas, except when the ammonia producing retort or apparatus,
and a gas generator, are arranged in combination for the purpose of eliminating
free nitrogen from the gas produced in the said generator. Moreover I do not
claim the removal of the carbonic oxide from the gas except in combination with
an ammonia process for removing the nitrogen from the gas, or with any process
by which aminonia is artificially and purposely produced as a part of the process
of manufacturing a heating or lighting gas through the decomposition of steam

page_text: by incandescent carbon. Nor do I claim the process of purifying gas from carbonic
acid and sulphuretted hydrogen by means of ammonia except in combination with
the second and third parts of my process, herein before described, or with either of
then. And further I do not claim, nor do I bind myself to use any particular
process of regenerating the ammonia. And I do not claim the process of producing
merchantable soda salts by means of ammonia except in combination with other
parts of my process. In fact I do not broadly claim as new per se any one of the
several sub-processes which go to make up my improved process as a whole nor
any special part of the apparatus, herein described, separately, and of itself, but I
claim
First. The process herein described of generating and purifying heating or
illuminating gas, consisting as a whole, in the combination of the several sub-
processes, as follows, that is to say :-First. Injecting or forcing air or steam into
and through incandescent carbon contained in a suitable furnace, thereby causing
the air and steam to combine with the carbon and to produce carbonic oxide and
carbonic acid, the hydrogen of the decomposed steam and the nitrogen of the air
being at the same time set free; second, the separation of the nitrogen froin the
gas by converting it into ammonia, the said conversion being effected by causing
the nitrogen to combine with carbon and alkali so as to form cyanogen or com-
pounds thereof, by means of steam (the product being ammonia, oxides of carbon,
and alkali) and subsequently removing the ammonia; third, decomposing the
carbonic oxide in the gas and converting it into carbonic acid by means of highly
heated or incandescent steam, the product of the said decomposition being carbonic
acid and free hydrogen gas; fourth, the removal of the carbonic acid from the gas
by means of the previously formed ammonia; fifth, the conversion of the ammonia
and carbonic acid of the gas into carbonates and other commercial sults, all
substantially as described.
Second. In the process herein described of manufacturing and purifying heating
or illuminating gas, the combination of the several sub-processes as follows, that is
to say-first, injecting or forcing air and steam into and through incandescent
carbon contained in a suitable furnace, thereby causing the air and steam to combine
with the carbon and to produce carbonic oxide and carbonic acid, the hydrogen of
the decomposed steam and the nitrogen of the air being at the same time set free;
second, the separation of the nitrogen from the gas by converting it into ammonia,
the said conversion being effected by causing the nitrogen to combine with carbon
and alkali so as to form cyanogen or compounds thereof, and subsequently decom-
posing such cyanogen or its compounds, by means of steam, (the product being
ammonia, oxides of carbon, and alkali) and subsequently removing the ainmonia;
third, decomposing the carbonic oxide in the gas and converting it into carbonic
acid by means of highly heated or incandescent steam, the product of the said
decomposition being carbonic acid and free hydrogen gas; fourth, the removal of
the carbonic acid from the gas by means of the ammonia previously formed; all
substantially as described.
Third. The process herein described of manufacturing heating or illuminating
gas, through the decomposition of steam and air by incandescent carbon, in com-
bination with the further process of separating the resulting nitrogen from the
crude gas, consisting in introducing the said said gas into a suitable retort, or series
of retorts, containing carbon and alkali, or any suitable form, compound or com-
bination thereof, in an incandescent state and causing the said nitrogen or a part
thereof, in the presence of the said alkali and carbon, to combine therewith and
form cyanogen, or compounds thereof, and subsequently decomposing such cyanogen,
or its compounds, by means of steam, thereby forming ammonia, all substantially
as described.
Fourth. The process herein described of manufacturing nitro-genized “water gas,"
in combination, with the further process of separating the nitrogen and carbonic
oxide therein contained, consisting in first introducing the crude gas into a suitable
retort, or series of retorts, containing carbon and alkali in an incandescent state and

page_text: causing the said gas to combine therewith to form cyanogen, or compounds thereof,
and subsequently decomposing such cyanogen, or its compounds, by means of steam,
the products of the said decomposition being ammonia, oxides of carbon, and alkali;
second, removing the ammonia from the gas by means of suitable scrubbers; third,
removing the carbonic oxide from the gas by causing it to be decomposed by highly
heated or incandescent steam, the result of such decomposition being carbonic acid
and free hydrogen, all substantially as described.
Fifth. The process herein described of manufacturing gas from steam and air
decomposed by incandescent carbon, in combination with the further process of
purifying such gas from its nitrogen and carbonic oxide, consisting in first con-
verting the nitrogen into ammonia and separating the same from the gas, and then
decomposing the carbonic oxide into carbonic acid, in contact with highly heated
or incandescent steam, all substantially as described.
Sixth. The process herein described of manufacturing gas from steam and air
decomposed by incandescent carbon, in combination with the further process of
purifying such gas from its nitrogen and carbonic oxide, consisting in first con-
verting the nitrogen into ammonia and the carbonic oxide into carbonic acid and
then combining the ammonia and carbonic acid, thereby producing carbonates of
ammonia, and subsequently decomposing the said carbonates by means of chloride
of sodium thereby producing chloride of ammonium and carbonates of soda, all
substantially as described.
Seventh. The furnace U containing a retort V, in combination with and placed
between the scrubbers X, b in the manner, and for the purposes, described.
Eighth. The combination of the furnace or cupola A, the retorts K, V, and the
scrubbers X, b, arranged for operation as described.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Twenty-sixth day of August in the year of Our Lord
One thousand eight hundred and eighty two.