Improvements in the Purification of Gas.
Year: 1891

page_text: Date of Application, 11th Aug., 1891
Complete Specification Left, 11th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Purification of Gas.
A communication from Messrs. SOLVAY & Co., of 19, Rue du Prince-Albert,
Brussels, Belgium, Manufacturers.
I, WILLIAM LLOYD WISE of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, do hereby declare the nature of
this invention to be as follows:-
It is well known that illuminating gas always retains a small quantity of carbonic
acid which it is difficult to entirely remove from the gas, notwithstanding the use of
the purifying substances that have long been employed for the purpose. The last
traces especially of the carbonic acid are refractory or difficult to eliminate, yet
these traces are injurious because they appreciably diminish the illuminating power
of the gas.
My correspondents have discovered that ferrite of soda possesses the property of
retaining even the slightest trace of carbonic acid contained in a neutral gas such
as atmospheric air or illuminating gas, and that it can be readily regenerated, so as
to possess its original properties, after it has become saturated with carbonic acid.
Ferrite of soda can for this purpose be prepared in the manner and has the
properties described in the Specifications of former Letters Patent No. 4364 dated
14th September 1882; and No. 1974 dated 8th February 1887. For the object
here in view, it is sufficient to state that ferrite of soda can be obtained in the form
of a brownish granular powder readily permeable by gases. Under the action of
carbonic acid, the ferrite of soda becomes carbonated and converted into an
extremely intimate mixture of carbonate of soda and ferric oxide. This reaction
will take place at the ordinary temperature.
By heating this mixture to a temperature above 700°, either in a muffle furnace,
or in a reverberatory furnace, or in rotary furnaces of the kind described in the
Specification of former Letters Patent granted to my correspondents for this
purpose, the ferrite of soda can be regenerated for re-use. This operation is even
much easier than that of preparing the ferrite of soda in the first instance, because
the mixture is a molecular one and much more intimate than the physical or
mechanical mixture originally used.
In applying this invention in a gas works for the purpose of purifying illuminating
gas, it will only be necessary to add a purifying box charged with ferrite of soda
to the ordinary purifying plant.
When the ferrite of soda has become inactive or spent, by reason of its decom-
position by carbonic acid, it is heated to a red heat, in a gas retort for instance, by
which treatment it will be rendered fit for re-use.
The ferrite of soda will also retain sulphuretted hydrogen present in the gas
treated, but the resulting sulphide is not so readily adapted for regeneration as is
the carbonate.
Dated this 11th day of August 1891.
W. LLOYD WISE,
Per F. J. Brougham.

page_text: COMPLETE SPECIFICATION.
Improvements in the Purification of Gas.
A. communication from Messrs. SOLVAY & Co., of 19, Rue du Prince-Albert,
Brussels, Belgium, Manufacturers.
I, WILLIAM LLOYD WISE of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, 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:-
It is well known that illuminating gas always retains a small quantity of carbonic
acid which it is difficult to entirely remove from the gas, notwithstanding the use
of various purifying substances that have long been employed for the purpose.
The last traces especially, of the carbonic acid are refractory or difficult to
eliminate, yet these traces are injurious because they appreciably diminish the
illuminating power of the gas.
My correspondents have discovered that ferrite of soda possesses the property of
retaining even the slightest trace of carbonic acid contained in a neutral gas such
as atmospheric air or illuminating gas passed over or through it, and that after it
has become saturated with carbonic acid, it can be readily regenerated, so as to
again acquire its original properties.
Ferrite of soda suitable for this purpose can be prepared in the manner, and has
the properties, described in the Specifications of former Letters Patent No. 4364
dated 14th September, 1882; and No. 1974 dated 8th February 1887. For the
object here in view, it is sufficient to state that ferrite of soda can be obtained in
the form of a brownish granular powder readily permeable by gases. Under the
action of carbonic acid, the ferrite of soda becomes carbonated and converted into
an extremely intimate mixture of carbonate of soda, and ferric oxide. This
reaction will take place at the ordinary temperature. By heating this mixture to
a temperature above 700° C., as for examples in a muffle furnace, or in a rever-
beratory furnace, or in rotary furnaces of the kind described in the Specification of
former Letters Patent granted to my correspondents for this purpose, the ferrite of
soda can be regenerated for re-use. This operation is even much easier to effect
than that of preparing the ferrite of soda in the first instance, because the mixture
is a molecular one and much more intimate than the physical or mechanical mixture
originally used.
When applying this invention in a gas works for the purpose of purifying
illuminating gas, it will only be necessary to add a purifying box charged with
ferrite of soda to the ordinary purifying plant, and to pass the gas to be purified
through this box and the ferrite of soda therein.
When the ferrite of soda has become inactive or spent, by reason of its decom-
position by the carbonic acid in the coal gas, it is heated to a red heat, in a gas
retort for instance, by which treatment it will be rendered fit for re-use.
The ferrite of soda will also retain sulphuretted hydrogen present in the gas
treated, but the resulting sulphide of soda cannot be so readily reconverted into
ferrite of soda for re-use, as is the carbonate.
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 :-
:-
In the purification of illuminating or other gas or gases having no action upon
the ferrite of soda,
(a) The use of ferrite of soda for the removal of carbonic acid from the said
gas or gases substantially as herein before described.

page_text: (b) The use of ferrite of soda for the purpose set forth hereinabove combined
with the regeneration of the said ferrite of soda by means of heat after
it has become inactive or spent substantially as hereinbefore described.
Dated this 11th day of May 1892.
W. LLOYD WISE,
Per F. J. Brougham.