Improvements in the Desulphurization of Gaseous Products.
Year: 1887

page_text: Date of Application, 19th July, 1887
Complete Left, 19th Apr., 1888
Complete Accepted, 15th June, 1888
PROVISIONAL SPECIFICATION.
Improvements in the Desulphurization of Gaseous Products.
We JOHN JAMES HOOD Analytical Chemist of 21 Shepherd's Bush Road in the
County of Middlesex and ALFRED GORDON SALAMON Analytical Chemist of 1 Fen-
church Avenue in the City of London do hereby declare the nature of this invention
to be as follows:-
These improvements relate to the desulphurizing of gaseous products, such as the
gases obtained by the destructive distillation of coal for use in illumination; and
also to the absorption and destruction of sulphurous acid fumes or sulphuretted
hydrogen evolved during chemical operations, or when these gases are produced
during the combustion of materials containing sulphur.
The process has also for its object the recovery of the sulphur.
The material which we employ to effect the desulphurization is what is known as
Weldon mud, being, in chemical terms, a more or less hydrated mixture of the
oxides of manganese, principally of the dioxide, combined with more or less oxide of
calcium. This manganese mud is, as is well known, prepared by precipitation of
a soluble manganese compound such as the chloride, with lime, and blowing
atmospheric air through the liquid in which the manganese oxide is suspended so
as to oxidise it to the highest degree possible.
We employ this mud in either of the following ways:-(1) The gas to be desul-
phurized may be forced through the manganese mud held in water, acidulated or not;
(2) the manganese mud is drained, and if not sufficiently porous, mixed with plaster
of Paris and dried. When this mixture is placed in layers, the gas is passed over
it. Towers may be conveniently used for containing the dried manganese nud. The
manganese mud may be mixed with acid before drying, or it may be used in its original
alkaline state, in which latter way we prefer to employ it.

page_text: If the mud be used mixed with acid, and sulphuretted hydrogen passed over it, a
salt of manganese is formed, and free sulphur deposited; if not acid, a sulphide of
manganese and free sulphur are formed.
In desulphurizing gases, such as coal gas, containing sulphide of carbon in addition
to sulphuretted Hydrogen or sulphurous acid, besides using manganese mud to
destroy the latter gases, we employ some of the manganese sulphide to absorb the
carbon disulphide, just as lime-sulphide is used for a similar purpose.
The manganese residues obtained by the desulphurizing process are dissolved in acid,
and the free sulphur that deposits is separated,-the sulphuretted hydrogen evolved
being utilized for sulphuric acid making or other purposes. The manganese solution
is again precipitated with lime, air blown through to effect oxidation, and the mud is
again ready for use.

page_text: COMPLETE SPECIFICATION.
Improvements in the Desulphurization of Gaseous Products.
We JOHN JAMES HOOD, Analytical Chemist, of 21 Shepherd's Bush Road in the
County of Middlesex, and ALFRED GORDON SALAMON, Analytical Chemist, of 1
Fenchurch Avenue in the City of London, do hereby declare the nature of this
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 the desulphurizing of gaseous products, such as the
gases obtained by the destructive distillation of coal for use in illumination, and for
the absorption of sulphurous fumes or sulphuretted hydrogen evolved during chemical
operations, or when these gases are produced during the combustion of materials
containing sulphur.
The invention has also for its object the recovery or utilisation of the sulphur
absorbed or fixed by the desulphurizing material.
The material which we employ to effect the desulphurizing or absorption is
artificially prepared hydrated dioxide of manganese, or a mixture of this with other
lower oxides of manganese, such an artifically prepared manganese material being that
known as "Weldon mud." This substance, in chemical terms, is a more or less hydrated
mixture of the oxides of manganese, principally of the dioxide, combined with more
or less oxide of calcium.
This "Weldon mud" is, as is well known, prepared by precipitation of a soluble
manganese compound, such as the chloride, with lime, and blowing atmospheric air
through the liquid in which the manganese oxide is suspended, so as to oxidize it to
the highest degree possible.
Or we employ this same Weldon mud after it has been employed for removing the
ferric oxide from aluminic sulphate, after which use, the mud has become contaminated
with a small quantity of oxide of iron and some sulphate of lime; but otherwise
consists essentially of an hydrated peroxide of manganese.
We employ this mud in either of the following ways: -(1) The gas to be
desulphurized may be forced through the manganese mud held in suspension in water,
acidulated or not acidulated; (2) The manganese mud is washed practically free
from calcium chloride, drained, and if not sufficiently porous, it is mixed with plaster
of paris or other suitable material, and dried.
When this material is placed in lay ers in a convenient apparatus, the gas is passed
over and through it.
The manganese mud may be mixed with acid before drying, or it may be used
in its original alkaline state, in which latter way we usually prefer to employ it.
If the mud be used mixed with acid, and sulphuretted hydrogen be passed over it,
a salt of manganese is formed and free sulphur deposited. If not acidulated, a
sulphide of manganese and free sulphur are formed.

page_text: In desulphurizing gases such as coal gas containing sulphide of carbon in addition
to sulphuretted bydrogen, besides using Weldon mud to fix the latter, we employ
some of the manganese sulphide to absorb or fix the bisulphide, just as lime sulphide
is used for a similar purpose.
After the manganese mud has been fully charged with sulphur, we expose the
material to atmospheric oxidation, and thus render it again efficient for desulphuriza-
tion.
This revivification we repeat five or more times, until the material becomes highly
charged with sulphur, and we then treat it as follows:-The manganeso residues
obtained by the desulphurizing process are dissolved in acid; the free sulphur that
deposits is separated, there being little or no sulphuretted hydrogen evolved during
the dissolving, if the material has been previously subjected to exposure to the atmos-
pheric air for some days. The manganese solution is again precipitated with lime;
air is blown through to effect oxidation, and the mud, after washing and drying, is
again ready for use.
Instead of using acid for the recovery of the sulphur the sulphured manganese may
be burned in the ordinary furnaces of sulphuric acid chambers, and the residue of
oxides of manganese may be employed for the manufacture of chlorine.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
:-
The use of Weldon mud (artificially prepared hydrated oxides of manganese) in the
desulphurization of gaseous products as described, whereby the sulphur so absorbed or
fixed may be recovered or utilised.
Dated this 19th day of April 1888.
NEWTON & SON,
Agents for the Applicants.