IMPROVEMENTS IN APPARATUS AND PROCESS FOR THE MANUFACTURE OF HYDROGEN GAS
Year: 1882

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for
an Invention of "IMPROVEMENTS IN APPARATUS AND PROCESS FOR THE
MANUFACTURE OF HYDROGEN GAS" Communicated to him from abroad by
William H. Bradley of the City County and State of New York in the
United States of America
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 12th October 1882.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
APPARATUS AND PROCESS FOR THE MANUFACTURE OF HYDROGEN GAS " [Com-
municated to him from abroad by William H. Bradley of the City County and
State of New York in the United States of America]
The Invention relates to the economical production of hydrogen gas to be used
primarily for the manufacture of illuminating gas or for any other purpose where
it may be required.
It is well known that if steam be decomposed in the presence of hydrocarbon at.
a high temperature, the resultant gases are a mixture of carbonic acid and hydrogen
with a small per centage of carbonic oxide and marsh gas. When the hydrogen is
used for the manufacture of illuminating gas the presence of the marsh gas is useful
and it is allowed to remain, but for most purposes the carbonic oxide and carbonio
acid gases should be eliminated and to accomplish this result is the object of the
Invention.
In the drawings (Figure 1) A represents a front elevation-A' represents a
sectional elevation-B the blow valve and purge pipe-0 the "take off pipe "-D
the wash box or hydraulic seal-E and E' the inlet pipe for furnace or heating gas-
F and F the air pipe G the inlet pipe for steam and hydrocarbon-G³ super-
heated steam pipe-H overflow valve for regulating the hydraulic seal. Numbers
1, 2, 3, 4 and 5 are purge or blow off valves for use in heating up as hereinafter
described or to furnish free egress for the air contained in the apparatus.
Numbers 6 and 7 are inlet valves for admitting or shutting off furnace gas.

page_text: Numbers 8 and 9 inlet valves for admitting or shutting off air to induce com-
bustion of furnace gas in the interior of chambers A and A¹. Numbers 10 and 11
levers connected with cocks similarly numbered on plan to admit or shut off steam
and hydrocarbon.
To carry the Invention into effect I proceed as follows: The chambers or
generators A and A' are filled with lump lime. The inlet valves 6 and 7 in the
pipes E and E' conveying furnace gas from a carbonic oxide gas generator (not
shown) and the inlet valves 8 and 9 in the air-conveying pipes E and F being also
opened and all other valves being closed except the purge valve 1 the mixture of
air and carbonic oxide is ignited and allowed to burn until the lump lime in the
two chambers has become highly heated; during this operation the outlet valve 1
in pipe B should be kept open to allow the products of combustion to freely pass
off. When the lime in chambers A and A¹ is sufficiently heated, the valves 6
and 7 in pipes E and E¹, and the valves 8 and 9, in pipes F and F¹ are closed,
valve 10 in pipe G is then opened, and admitting steam from an ordinary boiler
and super heater (not shown) charged with hydro-carbon vapor; or, if preferable,
liquid hydrocarbon may be admitted through a pipe similar to the steam pipe.
The valve 1 in pipe B is then closed and valve 3 in top of chamber A¹ opened for
an instant in order to allow the remaining air to escape then valve 3 is closed
and valve 4 opened when the gas passes through the hydraulic seal in wash box D
and finally through "take off pipe " C.
The office of the lime in the second chamber A¹ being to extract the carbonic
acid generated at the same time with the hydrogen by the decomposition of the
steam and hydrocarbon in the chamber A.
When the beat in chamber A has become reduced below the decomposing degree,
the steam and hydrocarbon are shut off and Siemens furnace gas and air admitted
and ignited in chamber A' in like manner as above described for chamber A-
chamber A' then becomes the decomposing chamber. During the process of heating
the lime in chamber A¹ superheated steam is introduced into chamber A and the
same operation is repeated as before mentioned, thus making an alternate producing
apparatus. It may however be found more economical to use chamber A as the
decomposing chamber and chamber A¹ as a purifying chamber. Thus instead of
being an alternate producing apparatus it could be used as a continuous one. The
operation would then be substantially as follows: Chambers A and A' being filled
with lumps of caustic lime and the lime in both chambers heated as above
indicated, and the valves operated as above described steam and hydrocarbon are
introduced in chamber A where they are decomposed into hydrogen and carbonic
acid gases which pass to the other chamber, also containing highly heated lime,
where the carbonic acid is wholly extracted and the hydrogen passing the seal
box D is collected. As soon as the temperature of the lime in the decomposing
chamber has become too low to induce the decomposition of the steam and hydro-
carbon, valve 10 is closed and the purge valves opened; the lime in chamber A is
again heated and superheated steam is introduced into the other chamber, by
which latter operation the carbonic acid which the highly heated lime had absorbed
during the passage of the mixture of hydrogen and carbonic acid is expelled. The
time required to heat the lime in one chamber, and that required to expel the
carbonic acid from the carbonate of lime in the other by means of superheated
steam, are about the same; so that the operation may be substantially continuous
and economical and practical. On the same principle in substance an apparatus
has been erected by my correspondent with which during his experiments produced
an aggregate of 84000 cubic feet of gas.
In the practical working of the above described apparatus it may be required to
use more than one purifying chamber to one decomposing chamber, especially when
the purifying chamber is of less cubic capacity than the other.
The absorption of carbonic acid gas by heated lime and its subsequent elimination
by means of superheated steam from the comparatively dry carbonate of lime are,

page_text: I believe, new and they form an important part of the Invention in connection
with the apparatus.
In order to produce carbonic acid and hydrogen gases alone the steam must be
rather in excess as regards the hydro-carbon used or introduced into the
decomposing chamber, so that a small amount of undecomposed watery vapor may
pass with the gases and coming in contact with the dry lime in the purifying
chamber, may form an hydrate of lime capable of effecting the extraction of the
carbonic acid; but when subsequently dry and highly superheated steam is
introduced into the purifying chamber or chambers the carbonate of lime is again
rendered an oxide of calcium. This operation can be often repeated.
I am aware that several attempts have been made to extract carbonic acid gas
by means of dry lime, but so far none has been successful. They have failed
because the lime, intended to extract the carbonic acid, has not been sufficiently
heated and steam has not been introduced. If carbonate of lime be heated in a
tube until it begins to give off carbonic acid gas, and the heat be then lowered to
such a degree that the evolution of gas ceases, this evolution will immediately
recommence if steam be passed through the tube; for, at a high temperature, the
affinity of carbonic acid for lime is not sufficient to keep it from mingling with
steam. Thus, while carbonate of lime gives up its carbonic acid when heated to
redness in steam or the open air, quick lime on the other hand absorbs carbonic
acid in very great abundance when heated very hot in an atmosphere of that gas.
The decomposing chamber may be filled either with lime alone or with any other
refractory material such as oxides of aluminium and magnesium. The latter will
accomplish the same result as the oxide of calcium, provided however that as in
the case of lime, the quantities of the bodies present which act upon each other,
are substantially in equivalent proportion and in the presence of sufficient heat.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sydney Pitt in the Great Seal Patent Office on the 12th April
1883.
"
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
APPARATUS AND PROCESS FOR THE MANUFACTURE OF HYDROGEN GAS (A com-
munication to me from abroad by William H. Bradley of the City, County and
State of New York in the United States of America)
The invention relates to the economical production of hydrogen gas to be used
primarily for the manufacture of illuminating gas or for any other purpose where
it may be required.
It is well known that if steam be decomposed in the presence of hydrocarbon at
a high temperature, the resultant gases are a mixture of carbonic acid and hydrogen
with a small per centage of carbonic oxide and marsh gas. When the hydrogen
is used for the manufacture of illuminating gas the presence of the marsh gas is
useful and it is allowed to remain, but for most purposes the carbonic oxide and 1
carbonic acid gases should be eliminated and to accomplish this result is the object
of this invention.
In the drawings (Figure 1.)
A represents a front elevation. A' represents a sectional elevation. B the blow
valve and purge pipe. C the "take off pipe." D the wash box or hydraulic seal. 2
E and E¹ the inlet pipe for furnace or heating gas. F and F¹ the air pipe. G the
inlet pipe for steam and hydrocarbon. G' superheated steam pipe. H overflow
valve for regulating the hydraulic seal.
Numbers 1. 2. 3. 4 and 5 are purge or blow off valves for use in heating up
as hereinafter described or to furnish free egress for the air contained in the 2
apparatus.
Numbers 6 and 7 are inlet valves for admitting or shutting off furnace gas.
Numbers 8 and 9 inlet valves for admitting or shutting off air to induce
combustion of furnace gas in the interior of chambers A and A¹.
Numbers 10 and 11 levers connected with cocks similarly numbered on plan to 3
admit or shut off steam and hydrocarbon.
To car y this invention into effect I proceed as follows:-'
-The chambers or
generators A and A¹ are filled with lump line. The inlet valves 6 and 7 in the
pipes E and E conveying furnace gas from a carbonic oxide gas generator (not
shown) and the inlet valves 8 and 9 in the air-conveying pipes E and F being also 3
opened and all other valves being closed except the purge valve 1 the mixture
of air and carbonic oxide is ignited and allowed to burn until the lump lime in
the two chambers has become highly heated; during this operation the outlet
valve 1 in pipe B should be kept open to allow the products of combustion to
freely pass off. When the lime in chambers A and A is sufficiently heated, the 4
valves 6 and 7 in pipes E and E¹, and the valves 8 and 9, in pipes F and F¹ are
closed, valve 10 in pipe G is then opened and admitting steam from an ordinary
boiler and super-heater (not shown) charged with hydrocarbon vapor; or, if
preferable liquid hydrocarbon may be admitted through a pipe similar to the
steam pipe. The valve 1 in pipe B is then closed and valve 3 in top of chamber A¹
opened for an instant in order to allow the remaining air to escape-then valve 3
is closed and valve 4 opened when the gas passes through the hydraulic seal in
wash-box D and finally through "take off pipe " C.
The office of the lime in the second chamber A¹ being to extract the carbonic
acid generated at the same time with the hydrogen by the decomposition of the 5
steam and hydrocarbon in the chamber A.

page_text: When the heat in chamber A has become reduced below the decomposing degree,
the steam and hydrocarbon are shut off and Siemens furnace gas and air admitted
and ignited in chamber A¹ in like manner as above described for chamber A.
Chamber A¹ then becomes the decomposing chamber. During the process of
heating the lime in chamber A' superheated steam is introduced into chamber A,
and the same operation is repeated as before mentioned, thus making an alternate
producing apparatus. It may however be found more economical to use chamber A
as the decomposing chamber and chamber A¹ as a purifying chamber. Thus
instead of being an alternate producing apparatus it could be used as a continuous
one. The operation would then be substantially as follows: Chambers A and A¹
being filled with lumps of caustic lime and the lime in both chambers heated as
above indicated, and the valves operated as above described steam and hydrocarbon
are introduced in chamber A where they are decomposed into hydrogen and
carbonic acid gases which pass to the other chamber, also containing highly heated
lime, where the carbonic acid is wholly extracted and the hydrogen passing the seal
box D is collected. As soon as the temperature of the lime in the decomposing
chamber has become too low to induce the decomposition of the steam and
hydrocarbon, valve 10 is closed and the purge valves opened; the lime in
chamber A is again heated and superheated steam is introduced into the other
chamber, by which latter operation the carbonic acid which the highly heated lime
had absorbed during the passage of the mixture of hydrogen and carbonic acid is
expelled. The time required to heat the lime in one chamber and that required to
expel the carbonic acid from the carbonate of lime in the other by means of
superheated steam, are about the same; so that the operation may be substantially
continuous and economical and practical. On the same principal in substance an
apparatus has been erected with which during experiments an aggregate of 84,000
cubic feet of gas has been produced.
In the practical working of the above described apparatus it may be required to
use more than one purifying chamber to one decomposing chamber, especially
when the purifying chamber is of less cubic capacity than the other.
The absorbtion of carbonic acid gas by heated lime and its subsequent elimination
by means of superheated steam from the comparatively dry carbonate of lime are
I believe new and they form an important part of this invention in connection
with the apparatus.
In order to produce carbonic acid and hydrogen gases alone the steam must be
rather in excess as regards the hydrocarbon used or introduced into the decomposing
chamber, so that a small amount of undecomposed watery vapor may pass with the
gases and coming in contact with the dry lime in the purifying chamber, may form
an hydrate of lime capable of effecting the extraction of the carbonic acid; but
when subsequently dry and highly superheated steam is introduced into the
purifying chamber or chambers the carbonate of lime is again rendered an oxide of
calcium. This operation can be often repeated.
I am aware that several attempts have been made to extract carbonic acid gas
by means of dry lime; but so far none has been successful. They have failed
because the lime, intended to extract the carbonic acid, has not been sufficiently
heated and steam has not been introduced. If carbonate of lime be heated in
a tube until it begins to give off carbonic acid gas and the heat be then lowered to
such a degree that the evolution of gas ceases, this evolution will immediately
recommence if stean be passed through the tube; for, at a high temperature, the
affinity of carbonic acid for lime is not sufficient to keep it from mingling with
steam. Thus while carbonate of lime gives up its carbonic acid when heated
to redness in steam or the open air, quick lime on the other hand absorbs
carbonic acid in very great abundance when heated very hot in an atmosphere of
that gas.
The
The decomposing chamber may be filled either with lime alone or with any
other refractory material such as oxides of aluminium and magnesium.
latter will accomplish the same result as the oxide of calcium, provided however

page_text: that as in the case of lime, the quantities of the bodies present which act upon
each other, are substantially in equivalent proportion and in the presence of
sufficient heat.
What I claim is:-
First. In the manufacture of hydrogen gas by the decomposition of steam and
bydrocarbon in contact with a body of heated lime, the process of revivifying the
lime used in purifying the gas which consists in decarbonating the comparatively
dry carbonate of lime or carbonates of the alkaline earths by subjecting it while in
a heated condition to the action of the superheated steam substantially as above
described.
Second. The within described apparatus for the manufacture of hydrogen gas,
consisting of two or more vertical chambers A and A', the gas and air supply pipes,
the steam and oil supply pipes and a gas eduction pipe connected with the top
thereof and a purge pipe (provided with a valve) connected with the bottom
thereof and suitable valves in the inlet and outlet pipes all combined and operating
substantially as described.
In witness whereof I the said Sydney Pitt have hereunto set my hand
and seal this ninth day of April in the year of our Lord One thousand
eight hundred and eighty three.