IMPROVEMENTS IN OBTAINING SULPHUR FROM SULPHURETTED HYDROGEN
Year: 1883

page_text: LETTERS PATENT to Carl Friedrich Claus, of Mark Lane, in the City of
London, Chemist for an Invention of "IMPROVEMENTS IN OBTAINING SULPHUR
FROM SULPHURETTED HYDROGEN
"
"
PROVISIONAL SPECIFICATION left by the said Carl Friedrich Claus at
the Office of the Commissioners of Patents on the 31st December 1883.
CARL FRIEDRICH CLAUS, of Mark Lane, in the City of London, Chemist,
IMPROVEMENTS IN OBTAINING SULPHUR FROM SULPHURETTED HYDROGEN
"
To obtain free sulphur from sulphuretted hydrogen by my present invention,
the sulphuretted hydrogen being either pure or diluted by other gases, I add to the
said sulphuretted hydrogen or to the said mixture of sulphuretted hydrogen and
other gases, such quantity of air that there shall then be present with the
resulting mixture of gases either a little more or a little less free oxygen than the
quantity necessary to form water with the hydrogen of the sulphuretted hydrogen
contained therein, and I then pass the resulting mixture of gases through a bed
or layer of fragments or pieces or powder of solid material maintained at a suitable
temperature as will hereinafter be explained. The result is that the greater portion
of the sulphur of the sulphuretted hydrogen is set free in passing through the said
bed, the remainder thereof being either burnt into sulphurous acid gas and vapour
of water, or passing off as undecomposed sulphuretted hydrogen. I then collect
the sulphur which has been set free, and either allow to pass into the atmosphere
the gases which pass off from the said bed, and which contain a small quantity of
either sulphurous acid gas or sulphuretted hydrogen gas, as the case may be, or I
treat these gases for the absorption of the small proportion of sulphurous acid or
sulphuretted hydrogen contained in them by any well known means, as will be
well understood.
The bed or layer of fragments or pieces or powder of solid material which I
employ as above said must be contained in a vessel or kiln which must be
completely closed, except that it must communicate with a pipe or pipes by
means of which the mixture of gases containing sulphuretted hydrogen and free
oxygen may be fed into it, and also with a pipe or pipes for conveying away the

page_text: mixture of gases and vapours passing off from it. The said kiln, though I do not
confine myself to such form of it, may conveniently be an iron box lined with
brick or fireclay, or merely a brick chamber not externally clothed with iron, and
should preferably be furnished with either a false bottom pierced with holes, or
with a grid or other equivalent appliance, upon which the bed or layer of fragments
or pieces or powder of solid material should be spread, and the mixture of gases
containing sulphuretted hydrogen and either a little more or a little less than the
quantity of free oxygen necessary to burn the hydrogen of such sulphuretted
hydrogen may be fed into the kiln either below such false bottom or grid or above
it, the mixture of gases and vapours (resulting from the reaction which takes place
in the interstices of the material of which the bed contained in the kiln is composed)
passing out of the kiln in the opposite direction.
The bed or layer of solid material contained in the said vessel or kiln may
consist of oxide of iron or other metallic oxide, or of other not readily fusible solid
substance. The more porous the material of which the bed is formed the better,
and the smaller the fragments of which it is composed also the better, provided
only that such fragments be not too small to permit of the mixture of gases passing
sufficiently freely through the bed or layer of them. In my experimental
operations I have obtained good results when using the said material in powder,
and also when employing it in lumps or fragments of very various sizes. The depth
of bed which I have employed has varied from a few inches to several feet, and in
practice it may vary according to the state of division of the material of which the
bed is composed, and also according to the rate at which the mixture of gases is
fed into the kiln containing it. Except in the case which will be mentioned
below, the bed must always be heated up, by any convenient means, before the
mixture of gases is first admitted into the kiln; but the heat of the reaction
taking place in the interstices between the fragments or small pieces of which the
said bed is composed will afterwards maintain its temperature sufficiently, if the
operation be conducted continuously, if the mixture of gases upon which it is
performed be not too poor in sulphuretted hydrogen and free oxygen, and if the
rate at which the mixture of gases is fed into the kiln be not too slow. In other
cases it will be necessary to supplement the heat of the reaction in question by
heat from some other source, applied to the bed or layer of pieces or powder or
fragments of solid material externally or otherwise as may be most convenient in
each case, or by heating the air or the gases containing the sulphuretted hydrogen
or both, or by admitting combustible gas, such as carbonic oxide together with the
sulphuretted hydrogen and air.
Among the substances of any one of which, or of a mixture of any two or more
of which, the bed in question may be formed, I would indicate as perhaps the
cheapest and most convenient (though I do not confine myself to these substances),
fragments of brick, oxide of iron, oxide of manganese, asbestos (coated or
impregnated or not with a metal, an oxide, or a salt), alumina, oxide of zinc,
carbonate of zinc, lime, and calcium carbonate.
.
When the bed contained in the aforesaid kiln is composed either wholly or in
part of hydrated oxide of iron, hydrated oxide of manganese, or analogous substance,
it need not be heated up before commencing to pass into the kiln the mixture of
gases containing sulphuretted bydrogen and free oxygen. Such hydrated oxides
can start the required reaction or reactions at ordinary temperatures, and though
the heat developed by that reaction or those reactions soon renders the said
hydrated oxides anhydrous or nearly so, it at the same time heats the bed which
at first consisted wholly or in part of such hydrated oxide or oxides to such
temperature that, if the conditions otherwise be as above indicated, it can hence-
forth maintain such reaction or reactions, notwithstanding that the said oxide or
oxides have become nearly or completely dehydrated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Carl Friedrich Claus in the Patent Office on the 30th June
1884.
CARL FRIEDRICH CLAUS, of Mark Lane, in the City of London, Chemist,
"IMPROVEMENTS IN OBTAINING SULPHUR FROM SULPHURETTED HYDROGEN
13
To obtain free sulphur from sulphuretted hydrogen by my present invention, the
sulphuretted hydrogen being either pure or diluted by other gases, I add to the said
sulphuretted hydrogen or to the said mixture of sulphuretted hydrogen and other
gases, such quantity of air that there shall then be present with the resulting
mixture of gases either a little more or a little less free oxygen than the quantity
necessary to form water with the hydrogen of the sulphuretted hydrogen contained
therein, and I then pass the resulting mixture of gases through a bed or layer of
fragments or pieces or powder of solid material maintained at a suitable temperature
as will hereinafter be explained. The result is that the greater portion of the
sulphur of the sulphuretted hydrogen is set free in passing through the said bed,
the remainder thereof being either burnt into sulphurous acid gas and vapour of
water, or passing off as undecomposed sulphuretted bydrogen. I then collect the
sulphur which has been set free, and either allow to pass into the atmosphere the
gases which pass off from the said bed and which contain a small quantity of either
sulphurous acid gas or sulphuretted hydrogen gas, as the case may be, or I treat
these gases for the absorption of the small proportion of sulphurous acid or
sulphuretted hydrogen contained in them by any well known means, as will be
well understood.
The bed or layer of fragments or pieces or powder of solid material which I
employ as above said must be contained in a vessel or kiln which must be com-
pletely closed, except that it must communicate with a pipe or pipes by means of
which the mixture of gases containing sulphuretted hydrogen and free oxygen may
be fed into it, and also with a pipe or pipes for conveying away the mixture of
gases and vapours passing off from it. The said kiln, though I do not confine
myself to such form of it, may conveniently be an iron box lined with brick or
fire-clay, or merely a brick chamber not externally clothed with iron, and should
preferably be furnished with either a false-bottom pierced with holes, or with a
grid or other equivalent appliance, upon which the bed or layer of fragments or
pieces or powder of solid material should be spread, and the mixture of gases
containing sulphuretted hydrogen and either a little more or a little less than the
quantity of free oxygen necessary to burn the hydrogen of such sulphuretted
bydrogen may be fed into the kiln either below such false-bottom or grid or above
it, the mixture of gases and vapours (resulting from the reaction which takes place
in the interstices of the material of which the bed contained in the kiln is
composed) passing out of the kiln in the opposite direction.
The bed or layer of solid material contained in the said vessel or kiln may consist
of oxide of iron or other metallic oxide, or of other not readily fusible solid
substance. The more porous the material of which the bed is formed the better,
and the smaller the fragments of which it is composed also the better, provided only
that such fragments be not too small to permit of the mixture of gases passing
sufficiently freely through the bed or layer of them. In my experimental
operations, I have obtained good results when using the said material in powder,
and also when employing it in lumps or fragments of very various sizes. The depth
of bed which I have employed has varied from a few inches to several feet, and in
practice it may vary according to the state of division of the material of which the

page_text: bed is composed, and also according to the rate at which the mixture of gases is
fed into the kiln containing it. Except in the case which will be mentioned below,
the bed must always be heated up, by any convenient means, before the mixture of
gases is first admitted into the kiln; but the heat of the reaction taking place in
the interstices between the fragments or small pieces of which the said bed is
composed will afterwards maintain its temperature sufficiently, if the operation be
conducted continuously, if the mixture of gases upon which it is performed be not
too poor in sulphuretted hydrogen and free oxygen, and if the rate at which the
mixture of gases is fed into the kiln be not too slow. In other cases it will be
necessary to supplement the heat of the reaction in question by heat from some
other source, applied to the bed or layer of pieces or powder or fragments of solid
material externally or otherwise as may be most convenient in each case, or by
heating the air, or the gases containing the sulphuretted hydrogen or both, or by
admitting combustible gas, such as carbonic oxide, together with the sulphuretted
hydrogen and air.
Among the substances of any one of which, or of a mixture of any two or more
of which, the bed in question may be formed, I would indicate, as perhaps the
cheapest and most convenient (though I do not confine myself to these substances),
fragments of brick, oxide of iron, oxide of manganese, asbestos (coated or impreg-
nated or not with a metal, an oxide, or a salt), alumina, oxide of zinc, carbonate of
zine, lime, and calcium carbonate.
•
When the bed contained in the aforesaid kiln is composed either wholly or in
part of hydrated oxide of iron, hydrated oxide of manganese, or analogous substance,
it need not be heated up before commencing to pass into the kiln the mixture of
gases containing sulphuretted hydrogen and free oxygen. Such hydrated oxides
can start the required reaction or reactions at ordinary temperatures, and though
the heat developed by that reaction or those reactions soon renders the said
hydrated oxides anhydrous or nearly so, it at the same time heats the bed which
at first consisted wholly or in part of such hydrated oxide or oxides to such tem-
perature that, if the conditions otherwise be as above indicated, it can henceforth
maintain such reaction or reactions, notwithstanding that the said oxide or oxides
have become nearly or completely dehydrated.
Having thus fully described my said invention and the manner of performing
the same I wish it understood that what I claim as the invention to be secured to
me by the hereinbefore in part recited Letters Patent consists in treating either
pure or impure sulphuretted hydrogen for the obtainment of free sulphur therefrom
by passing such sulphuretted bydrogen, in admixture with either a little more or a
little less free oxygen than the quantity necessary to form water with the hydrogen
of the said sulphuretted hydrogen, through a bed or layer of fragments of suitable
solid material, maintained at a suitable temperature either by the heat of the
reaction which takes place as the said mixture of gases passes through the said
bed or layer of fragments of solid material, or by means of heat from some other
source applied to the said bed or layer in any convenient way, in order to obtain,
as free sulphur, such portion as may be desired of the sulphur of the said
sulphuretted hydrogen, the remainder of the sulphur of that sulphuretted hydrogen
passing off either as undecomposed sulphuretted hydrogen or as sulphurous acid, as
may be preferred in each particular case.
In witness whereof I the said Carl Friedrich Claus have hereunto set my hand
and seal this twenty eighth day of June in the year of Our Lord one thousand
eight hundred and eighty four
CARL FRIEDRICH CLAUS. (LS.)