IMPROVEMENT IN THE MANUFACTURE OF HYDROGEN GAS and
Year: 1885

page_text: I, ALEXANDER HENRY REED, of 90 Cannon Street in the county of Middlesex,
Engineer do hereby declare the nature of the said invention for AN IMPROVEMENT
IN THE MANUFACTURE OF HYDROGEN GAS and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
When bituminous coal or petroleum, or petroleum residue, or organic substances
containing or chiefly consisting of hydrogen and carbon are subjected to destructive
distillation, or when they or other substances, such as anthracite coal, coke, or
charcoal consisting chiefly of carbon are subjected to the action of highly heated
steam, the volatile or gaseous products obtained contain, besides hydrogen, a greater
or smaller proportion of carbon compounds, such as carbonic oxide and gaseous or
liquid hydrocarbons, or hydrocarbon vapors. The object of the present invention is
to remove the carbon compounds contained in the products obtained as above
stated, leaving hydrogen gas of a high degree of purity and adapted to the various
applications for which that substance may be used.
The first part of the invention relates to the conversion of the said carbon into
carbonic acid by the action of steam at a suitable temperature in contact with
certain substances hereinafter specified, which substances promote and facilitate the
action of the steam and permit the operation to be conducted with greater rapidity
and at a lower temperature than would be practicable by any means heretofore
proposed. During this operation the hydrogen of the steam is liberated in the free
state and is added to that originally present in or resulting from the products on
which the steam acts.
The second part of the invention relates to the removal of the carbonic acid gas
from the mixture of hydrogen and carbonic acid gases formed by the action of steam
in contact with the substances hereinafter specified, and the products on which the
steam acts.
In carrying out the invention, the process is as follows; take any gas containing
hydrogen and carbonic oxide, or hydrocarbon gases or vapors, or take vaporized
hydrocarbons, or liquid hydrocarbons, or any substances containing hydrogen and

page_text: carbon, such as water gas, or the gas obtained by destructive distillation with or
without the aid of steam, from coal, petroleum, petroleum residues, or organic
substances generally, or by the action of steam on these substances, or these
substances themselves either reduced to spray or vapor or melted or otherwise
suitably divided and bring the same in contact with metallic iron manganese,
copper, lead, tin or zinc or with the oxides of these metals or with mixtures
containing these metals or their oxides, in a vessel or receptacle of any suitable
form or size or material, such as a tube, chamber, retort, or other vessel, and
previously heated if required to such temperature as may be necessary for the action
to be obtained, for example a temperature ranging from incipient redness to a white
heat, for instance when iron or oxide of iron is used, a heat ranging from medium
redness to a high red will usually be found suitable. During the time when the
substances to be acted on are in contact with the metal or oxide, steam is caused to
enter the vessel and mix with the substances, or steam is caused to mix with the
substances to be acted on before they enter the vessel containing the metal before
specified, or the oxide thereof. In general it is preferable to heat the steam to, or
nearly to red heat before it enters the vessel containing the substances to be acted
upon and the metal or oxide, so as to avoid unduly cooling the latter, but this is
not in all cases essential to its action. In practice it is preferable to use an excess
of steam, over and above what is required to completely transform the carbon into
carbonic acid, so that unlecomposed steam may be present in the gases produced,
but in all cases it is requisite to employ a sufficient quantity of steam to burn up
all the carbon as hereinafter explained. The gases or vapors, or other substances
to be acted upon may also, if required, be, previous to being brought into contact
with the metal or oxide, heated to any suitable temperature. When metals such,
for instance as metallic iron, are used, it is preferable to admit steam until the metal
is more or less oxidized, before introducing the carbon compounds.
When the carbon compounds are brought into contact with steam and the metal
or oxide herein before specified at proper temperatures as above specified, the steam
and the carbon compounds re-act upon cach other, carbonic acid is formed, and
hydrogen is liberated; thus if water gas which consists of a mixture of hydrogen
carbonic oxide, and marsh gas, with some carbonic acid and nitrogen is the material
to be acted upon, the reactions which take place may be expressed by the following
equations. viz:

page_text: the metal or oxide and steam in the chamber or vessel in which the gas is generated,
or in a compartment of the said generating vessel instead of using a separate
chamber or vessel, gas may even be brought at the moment of its generation into
contact with the steam and metal or metallic oxide.
In the foregoing description, the terms, metallic iron, manganese, copper, lead, tin
or zinc have been used, but it is to be understood that when these metals, or any of
them are placed in the gas treating chamber in their natural state, that they must
first be oxidized by the action of the steain before they will begin to act in the
manner necessary to the carrying out of the process. The terins metallic oxide or
oxidized metal can therefore be used to define the substances employed in this
process.
After converting the carbon in the substances operated upon into carbonic acid as
above described and set forth, the gas is subjected to any convenient treatment to
remove the carbonic acid it contains. Thus it may be treated with lime as in the
usual process of purification of coal gas, or it may be passed through any suitable
form of apparatus containing carbonate of soda or carbonate of potassa, or solutions
which under the action of the said gas may yield carbonate, or bi-carbonate of soda,
or potassa which may be utilized for their commercial applications, or the gas may
be caused to come in contact with a solution of carbonate of soda or carbonate of
potassa, so as to form a solution of bi-carbonate of the base from which more or
less of the carbonic acid may be driven off by heat subsequently, and utilized for
its various applications if required, while the solution, after being cooled, may again
be used for the purification of a fresh quantity of the gas. In this latter form of
purification, it is preferable to use a continuous process by means of which the
solution of carbonate of soda or potassa is made to circulate first through the apparatus
through which the gas to be purified passes, wherein by spraying the solution,
causing the gas to bubble through, or to pass over it, or other well known devices,
the gas is brought into intimate contact with the solution. The solution then passes
through a heating apparatus of any known construction in which the carbonic acid
or more or less of it is expelled, and from which it may be conducted by suitable
pipes to apparatus in which it may be utilized. After passing through the heating
apparatus, the solution is cooled by any known device, and is finally returned to
the vessel containing the gas to be purified. Or the gases are brought, after cooling
them, into intimate contact with water under pressure, preferably in a vessel or
series of vessels through which a current of water can be made to pass in a direction
opposed to that in which the gas passes. The water is thus made to absorb a large
proportion of the carbonic acid contained in the gas and the remaining portion may
be removed by any of the means above described and set forth. After being
charged with carbonic acid, the water or solution of carbonate of potassa or soda
may be used to cool fresh portions of the gas by conducting the gas through pipes
around the outside of which the said water or solution circulates; during this
operation the water or solution becomes freed from the carbonic acid it previously
contained, or more or less of it, and may, after being cooled, be again used to absorb
carbonic acid from a fresh portion of gas. The carbonic acid evolved from the water
or solution during its use in cooling the gas, may be conveyed away by suitable
pipes and used for purposes to which it may be applied.
After removing the carbonic acid by the means above described, the residual gas
will, if the operation be properly performed, be found to be chiefly hydrogen gas,
and adapted to the various industrial applications, of that substance, or it may be
charged with illuminating gases or vapors, or subjected to any desired treatment for
communicating to it the properties of an illuminating gas.
I am aware of the English patents, No 2719; dated Oct 21, 1865 and N° 1471
dated April 23, 1873, granted to Johann Baggs, and which relate to the alternate
treatment of metallic iron with steam and carbonic oxide at high temperatures, and
the separate collection of the gaseous products thus obtained, and do not claim the
processes therein described.

page_text: Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed I declare that what
I claim is
1. The process of transforming gases, vapors, or substances containing carbon or
carbon compounds into mixtures of gases composed essentially of carbonic acid and
hydrogen which consists in the continuous introduction of such gases or vapors
together with an excess of steam into a chamber containing a metallic oxide or
oxidized metal, substantially as described.
2. The process of manufacturing hydrogen gas consisting in the continuous
introduction of gases, vapors, or substances containing carbon or carbon compounds
simultaneously along with steam into a chamber containing a metallic oxide or
oxidized metal followed by a treatment of the gascous products thereby obtained
with lime or the carbonates of potassa or soda or solutions thereof, or solutions in
which these substances may be formed under the action of the said gaseous
products, or with water for eliminating the carbonic acid they contain, substantially
as described.
3. The herein described process consisting in the continuous introduction of
gases, vapors, or substances containing carbon, simultaneously along with steam
into a chamber containing a metallic oxide or oxidized metal, passing the mixture
of hydrogen and carbonic acid resulting from said treatment over, through, or in
contact with the carbonate of potassa, or of soda, or solutions of said carbonates or
solutions in which these substances may be formed under the action of said mixture
of gases, and eliminating and utilizing the bye products, bi-carbonate of soda or
potassa and carbonic acid resulting from said process, substantially as described.