The Manufacture and Production of Material for Purifying Acetylene Gag.
Year: 1899

page_text: Date of Application, 26th May, 1899
Complete Specification Left, 31st Jan., 1900-Accepted, 3rd Mar., 1900
PROVISIONAL SPECIFICATION.
The Manufacture and Production of Material for Purifying Acetylene
Gag.
We, OTTO ERNST, Doctor of Philosophy and Chemist, and ALFRED PHILIPS,
Doctor of Philosophy and Chemist, both of 6, Kleine Taunusstrasse, Hoechst,
near Frankfort-on-Maine, in the German Empire, do hereby declare the nature
of this invention to be as follows:-
The object of this invention is to produce material for purifying acetylene gas
the said material possessing the advantages of great cheapness, energetic action,
and harmlessness towards the gas itself.
In purifying acetylene gas, materials have been hitherto employed either in
the dissolved state or in solid form.
The use of solutions has the disadvantage, that the liquid must either be
absorbed by some porous material such as kieselguhr (infusorial earth) or be
applied in a washing contrivance which is usually of inconvenient form and
requires considerable attention, and also some manipulative skill is demanded on
account of the acid character of the liquid. Therefore the use of solid purifying
agents has advantages, especially in the case of small illumination systems such
as house installations, table lamps and the like.
Amongst the solid materials which are capable of purifying acetylene from its
impurities (phosphoretted hydrogen, ammonia, and hydrogen sulphide) the salts
of hypochlorous acid are very advantageous on account of their acting well in the
dry state and their cheapness.
The calcium salt takes the first place among the hypochlorites, being easily
obtainable in the form of bleaching powder. Certain obstacles are incidental to
the use of bleaching powder in its commercial form, rendering its application to
the purifying of acetylene gas impracticable. In moist air it forms lumps which
cannot well be penetrated by the gas, and therefore give rise to waste of material.
Moreover, it has been observed (“Acetylen in Nissenschaft und Industrie erster
Iahrgang 1898 Heft 23, Seite 276) that when ordinary bleaching powder is used
in purifying acetylene gas, it becomes heated in consequence of decomposition,
and so constitutes a source of danger, and in using bleaching powder, as is also
the case with all other solid purifiers hitherto employed, in order to bring the
gas into close contact with the purifying agent, it becomes necessary, either to
spread it on wire trays, or sieves, in the purifier, or to mix it with light, chemi-
cally inactive materials such as kieselguhr, pumice or the like. In both cases
the purifying material occupies a large space.
We have succeeded in preparing from bleaching powder or other hypochlorites
a purifying material in fragments which material is highly porous, and yet so
solid that it is unnecessary either to spread it on trays or to convert it into
loose, bulky masses by admixture with inert substances before it can be applied
industrially in an economical manner. Spontaneous heating of the material is
thus avoided and the material remains highly porous and yielding under the

page_text: influence of moisture. The new purifying material according to this invention
is obtained by mixing the hypochlorite to a sludge with some substance in-
different to acetylene gas, spreading out the sludge in a thin layer, and then
drying it at such a temperature that no decomposition of the hypochlorite will
occur.
For admixture with the hypochlorite, all those substances can be used which,
on the one hand, are without deteriorating influence on acetylene gas, and on
the other hand yield a highly porous material when mixed with the salt and
subsequently dried.
In the first rank must be placed slaked lime, calcium carbonate, and similar
substances.
the
Calcium chloride can also be advantageously employed as
indifferent diluent, because it gives up its water of crystallisation when dried,
forming bubbles and pores.
Most descriptions of commercial bleaching powder contain, in addition to
hypochlorite, slaked lime and calcium chloride in quantity sufficient to admit of
their being treated in the manner indicated above without further admixture.
The following examples represent working methods of preparing the new
material. They are however examples merely, and the invention is not limited
strictly to them.
EXAMPLE I.
a uniform sludge
Twenty kilos of bleaching powder are stirred into
with water, and treated with a similar sludge composed of 5 kilos of
slaked lime and 5 kilos of calcium chloride, with water. The mass is thoroughly
incorporated, and dried in vacuo at 100° Centigrade, it being advantageous to
spread the material in comparatively thin layers on drying trays. The mass in
drying becomes highly porous, and sufficiently hard to allow of its being broken
into fragments of convenient size without falling to powder. Although drying
in vacuo is an assistance to the production of a highly porous condition, the
vacuum can be dispensed with under certain conditions, always provided that the
temperature does not rise so high as to risk decomposing the bleaching powder.
EXAMPLE II.
Fifty kilos of bleaching powder are stirred to a sludge with 30
kilos of water, and treated with 40 kilos of calcined sodium carbonate, whilst
stirring. The well mixed paste which now contains sodium hypochlorite and
calcium carbonate as a result of decomposition, is mixed with 10 kilos of calcium
This also
chloride and dried, preferably in racuo, at about 90° Centigrade.
yields a highly porous, solid purifying paste.
It is obvious that Example II can be so modified that chlorine is passed into a
concentrated solution of alkali, and the alkali hypochlorite obtained in this
manner treated with the necessary quantity of slaked lime or calcium chloride.
Similarly, the process can be applied when other methods of preparing the hypo-
chlorite are used, or can be made to directly follow these.
1
J of 1000
The Manufacture and Production of Material for Purifying Acetylene
Gas.
We, Orro ERNST, Doctor of Philosophy and Chemist, and ALFRED PHILIPS,
Doctor of Philosophy and Chemist, both of 6, Kleine Taunusstrasse, Hoechst,

page_text: near Frankfort-on-Maine, in the German Empire, do hereby declare the nature
of this invention and in what manner the same is to be performed to be par-
ticularly described and ascertained in and by the following statement:―
The object of our invention is to produce a material for purifying acetylene
gas, the said material possessing the advantages of great cheapness, energetic
action, and harmlessness, and not attacking the gas itself.
In purifying acetylene gas materials have been hitherto employed either in
the dissolved state, or in solid form.
The use of solutions has a disadvantage, because the liquid must either be
absorbed by some porous material such as kieselguhr, (infusorial earth), or it
must be applied in a washing contrivance which is usually of inconvenient form,
requiring considerable attention and also some manipulative skill on account of
the acid character of the liquid. Therefore it is obvious that the use of solid
purifying agents has advantages, especially in the case of small systems of illumi-
nation such as house-installations, table lamps, and the like.
Amongst the solid materials which are capable of depriving acetylene of its
impurities (phosphoretted hydrogen, ammonia, and hydrogen sulphide) the salts
of hypochlorous acid are very advantageous on account of their satisfactory action
in the dry state and their cheapness.
The first place among the hypochlorites is taken by the calcium salt, it being
easily obtainable in the form of bleaching powder. Certain obstacles however
are attendant upon the use of bleaching powder in its commercial form, rendering
its application to purifying acetylene gas impracticable. First the moisture of
the air or of the gas itself will cause the bleaching powder to form into lumps
which cannot well be penetrated by the gas and therefore give rise to waste of
material, and secondly it has been observed ("Acetylen in Wissenschaft und
Industrie" erster Jahrgang 1898 Heft 23, Seite 276) that when ordinary bleaching
1owder is used in purifying acetylene gas, it becomes heated in consequence of
decomposition, and so constitutes a source of danger. Moreover, in using bleach-
ing powder or any other solid purifier hitherto employed it becomes necessary,
either to spread it on wire trays, or sieves, in the purifier, or to mix it with
light, porous, materials such as kieselguhr, pumice stone, or the like, in order
to bring the gas into close contact with the purifying agent. In each instance
the purifying material occupies a large space.
We have now succeeded in preparing from bleaching powder, or other hypo-
chlorite, a purifying material in pieces which are highly porous, and yet so solid
that it is unnecessary either to spread it on trays, or to convert it into a loose
and bulky mass by admixture therewith of a porous substance before applying it
industrially. Spontaneous heating of the material is thus avoided, and the
material remains highly porous and yielding under the influence of moisture. The
new purifying material according to this invention is obtained by mixing the
hypochlorite and some substance indifferent to acetylene with water so as to form
a stiff sludge or paste and then spreading out the said sludge, or paste, in a thin
layer, and then drying it at such a temperature that no decomposition of the
hypochlorite will occur.
For admixture with the hypochlorite, all those substances may be used which
on the one hand, have no deteriorating influence on acetylene gas, and on the
other hand yield a highly porous material when mixed with the salt and subse-
quently dried.
In the first rank must be placed slaked lime, calcium carbonate, and similar
substances. Calcium chloride can also be advantageously employed as an indifferent
diluent, because it gives up its water of crystallisation when dried, forming
bubbles and pores.
Most kinds of commercial bleaching powder contain, in addition to hypo-
chlorite, slaked lime and calcium chloride in quantity sufficient to admit of their
being treated in the manner hereinhefore explained without further admixture.

page_text: The following examples represent working methods of preparing the new
material. They are however mere examples, and the invention is not strictly
limited to them.
EXAMPLE I.
a
Twenty kilos of bleaching powder are stirred with water into
uniform stiff sludge or paste, and treated with a similar sludge or paste made
by mixing 5 kilos of slaked lime and 5 kilos of calcium chloride and some
water. The two pastes are thoroughly mixed together and dried in vacuo at 100°
Centigrade, it being advantageous to spread the material in comparatively thin
layers on drying trays. The mass on drying becomes highly porous, and suffi-
ciently hard to allow of its being broken into pieces of convenient size without
falling to powder. Although drying in vacuo is advantageous to produce a
highly porous mass, the vacuum may under certain conditions be dispensed with,
always provided that the temperature does not rise so high as to risk decom-
position of the bleaching powder.
EXAMPLE II.
Fifty kilos of bleaching powder are stirred to a stiff sludge or paste
with 30 kilos of water, and treated with 40 kilos of calcined sodium car-
bonate, whilst stirring. The well mixed paste, which now contains sodium hypo-
chlorite and calcium carbonate as a result of decomposition, is mixed with 10
kilos of calcium chloride and then dried, preferably in vacuo, at about 90° Centi-
grade. This also yields a highly porous, solid material for use in purification.
It is obvious that Example II may be so modified that chlorine is introduced
into a concentrated solution of alkali, and the alkali hypochlorite thus obtained
is treated with the necessary quantity of slaked lime, or calcium chloride. In a
similar manner, the said process may be applied when other methods of preparing
the hypochlorite are used, or can be made to directly follow these.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is:
1. For purifying acetylene gas, a material consisting of a solid( highly porous
material containing a salt of hypochlorous acid.
2. For purifying acetylene gas, a material consisting of a solid, highly porous
material containing a salt of hypochlorous acid and slaked lime.
3. For purifying acetylene gas, a material consisting of a solid, highly porous
material containing a salt of hypochlorous acid, slaked lime, and calcium chloride.
4. The manufacture of a material for purifying acetylene gas, by stirring to a
sludge or paste with water a salt of hypochlorous acid and a substance or sub-
stances not attacked by acetylene gas and then drying the mass at a temperature
which will not decompose the salt of hypochlorous acid.
5. The manufacture of a solid, highly porous material for purifying acetylene
gas by stirring bleaching powder and some indifferent material and water to a
sludge or paste and then drying the mass at a temperature which will not decom-
pose the salt of hypochlorous acid.
6. The manufacture of a solid, highly porous material for purifying acetylene
gas by stirring bleaching powder with slaked lime and water to a sludge or paste
and then drying the mass at a temperature which will not decompose the salt of
hypochlorous acid.
7. The manufacture of a solid, highly porous material for purifying acetylene
gas by stirring bleaching powder with slaked lime and calcium chloride and
water to a sludge or paste and then drying the mass at a temperature which
will not decompose the salt of hypochlorous acid.
8. In the production of a material for purifying acetylene gas the combination
of a process for obtaining a solid, highly porous material containing a salt of
hypochlorous acid, with a process for obtaining the hypochlorite, in which the

page_text: hypochlorous liquor obtained by the latter process is stirred with some indifferent
material and water to a sludge or paste and then drying the mass at a tempera-
ture which will not decompose the salt of hypochlorous acid.
Dated this 31st day of January 1900.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.