IMPROVEMENTS IN THE PURIFICATION OF HYDROGEN GAS
Year: 1855

page_text: LETTERS PATENT to Félix Gabriel Célestin Dehaynin, of Paris, in the
Empire of France, and of 32, Essex Street, Strand, London, for the
Sealed the 26th June 1855, and dated the 3rd January 1855.
PROVISIONAL SPECIFICATION left by the said Félix Gabriel Célestin
Dehaynin, at the Office of the Commissioners of Patents, with his Peti-
tion, on the 3rd January 1855.
J, FÉLIX GABRIEL CÉLESTIN DEHAYNIN, of Paris, in the Empire of France,
and of 32, Essex Street, Strand, London, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE PURIFICATION OF HYDROGEN GAS'
to be as follows:-
These improvements relate to processes for seperating oxyd of carbon from
hydrogen gas, that is obtained by the decomposition of water on charcoal, and
by the distillation of peat, or in any other similar way. Hydrogen, as gene-
rated by the decomposition of water in the above ways, always contains a
considerable portion of carbonic oxyd, which renders it dangerous to use for
heating and lighting purposes. This quantity of oxyd of carbon is still further
increased, if, by raising the temperature and using charcoal in excess, the
carbonic acid generated by the above decomposition be entirely converted into
oxyd of carbon. Various means have hitherto been applied, but unsuccess-

page_text: fully, for purifying the hydrogen from its admixture on a manufacturing scale.
Anhydrous metallic oxyds cannot be used for that purpose, because they act
simultaneously on both the oxyd of carbon and on the hydrogen, forming
water with the latter. On the contrary, those alkaline or earthy alkaline
oxyds which powerfully retain the hydrating water have the property of con-
verting all the oxyd of carbon into carbonic acid without acting on the free
hydrogen; in fact, they genèrate, at the expense of the hydrating water, a
quantity of hydrogen, equal to the volume of the oxyd of carbon which has
been converted into carbonic acid. This reaction may be represented by the
following equation, in which M denotes an alkaline metal:-
M O, HỌ + C O = M O, C O + H.
The hydrated oxyds which may be used for that purpose are soda, potash,
barytes, strontion, &c.; but I prefer using caustic soda, with which I mix lime
water, & over this mixture I pass the hydrogen gas from which the carbonic
acid gas has already been separated by the ordinary processes. The hydrated
sodic lime must be exposed to a high temperature for burning the oxyd of
carbon; I put it for that purpose into cylinders or vessels of fire clay. The
soda thus used: may. be recovered again by. proper processes, and thus used
over & over again. From the preceeding example, it will be, seen that my
Invention consists in the combustion of the oxyd of carbon by means of
water, & of an alkaline oxyd, especially soda, whence results the absorption
of the carbonic oxyd by the same alkali, or by lime, with which it is mixed,
whence hydrogen is evolved, which is added to that generated by the direct
decomposition of water upon charcoal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Félix Gabriel Célestin Dehaynin in the Great Seal Patent
Office on the 2nd July 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FÉLIX
GABRIEL CELESTIN DEHAYNIN, of Paris, in the Empire of France, and of
S2, Essex Street, Strand, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of January, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Félix Gabriel Célestin Dehaynin, Her special licence that I, the said

page_text: Félix Gabriel Celestin Dehaynin, imy executors, administrators, and assigns,
or such others as. I, the said Félix Gabriel Célestin Dehaynin, my executors,
administrators,.and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter 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 THE PURIFICATION OF HYDROGEN GAS,"
upon the condition (amongst others) that I; the said Félix Gabriel Célestin
Dehaynin, by an instrument in writing under my hand and seal, 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. immé-
diately after the date of the said Letters Patent.
...NOW. KNOW YE, that I, the said Félix Gabriel Célestin Dehaynin, do
hereby declare the nature of the said Invention; and in what manner the
same is to be performed, to be, particularly described and ascertained in and
by the following statement:-
These improvements relate to processes for separating oxyd of carbon-from
hydrogen gas, that is obtained by the decomposition of water on charcoal, and
by the distillation of peat, or in any other similar way. Hydrogen, as genė-
rated by the decomposition of water in either of the ways mentioned, always
contains a considerable portion of carbonic oxyd, which renders it dangerous
to use for heating and lighting purposes: The oxyd thus contained in hydrogen
sometimes amounts to thirty per cent. of its own volume, and this quantity is
still further increased, if, by raising the temperature and using charcoal in
excess, the carbonic acid generated by the above decomposition be entirely
converted into oxyd of carbon. Various means have hitherto been tried, but
unsuccessfully, for purifying hydrogen from its admixture on a manufacturing
scale. Anhydrous metallic oxyds cannot be used for that purpose, because
they act simultaneously both on the oxyd of carbon and on the hydrogen,
forming water with the latter. On the contrary, those alkaline or earthy
alkaline oxyds which powerfully retain the hydrating water have the property
of converting all the oxyd of carbon at a red heat, or thereabout, into carbonic
acid without acting upon the free hydrogen; in fact, they generate, at the
expense of the hydrating water, a quantity of hydrogen gas, which is equal to
the volume of the oxyd of carbon that has been converted into carbonic acid.
This reaction may be represented by the following equation, in which M
denotes an alkaline metal:-
MO, HỌ + C O = M O, CO +.H..

page_text: The hydrated oxyds which may be, used for the purpose stated are soda,
potash, barytes, and strontia, and to facilitate the use of these alkaline metals
I mix them with slacked lime and let the mixture dry. In general, however,
I prefer using caustic soda, which I mix with lime, and over this mixture I
pass the hydrogen gas from which the carbonic acid has already been seperated
by the usual processes of purification. This hydrated sodic lime must be ex-
posed to a high temperature, in order to burn the oxyd of carbon, and for that
purpose I put the same into cylinders or vessels of fire clay, or of metal, such
as iron or cast iron. The caustic soda, by which the carbonic acid resulting
from oxydation of the oxyd of carbon is absorbed, may be recovered again by
proper processes, and thus repeatedly be used over again. For this purpose,
the mixture of soda and lime need only be lixiviated either alone or with a
fresh quantity of lime, the carbonate contained in said mixture being thus
rendered caustic again. The solution is then evaporated, and a fresh mixture
is formed; and this regenerating operation being repeated indefinitely, the
purification may by these means be carried on in an industrial and economic
way.
I am fully aware that the reaction expressed by the above equation has
been known to chemists for a long time, and has been set down in their works,
but it was never thought of applying said reaction to the manufacture of
heating or lighting gases, and no manufacturing means has been devised
before for removing from hydrogen, as generated by the decomposition of
water upon ignited coal, the oxyd of carbon contained in the hydrogen, which
by this admixture becomes one of the most poisonous gases. Hence, what I
claim as novel, and being secured to me by the herein-before in part recited
Letters Patent, is, the use and application to the manufacture of hydrogen gas
of the method of burning the oxyd of carbon by means of the water of an
alkaline oxyd, soda for instance, and absorbing the carbonic acid thus gene-
rated by the said alkaline oxyd, or by the lime with which it is mixed; also
evolving hydrogen from the hydrating water decomposed, this hydrogen being
added to that generated by the direct decomposition of water upon charcoal.
In witness whereof, I, the said Félix Gabriel Celestin Dehaynin, have
hereunto set my hand and seal, this 28th day of June, One thousand
eight hundred & fifty-five.
F. G. C. DEHAYNIN.
(L.S.)