Improvements in the Manufacture of Chlorine, and in the Treatment of Bye-products of the said Manufacture.
Year: 1895

page_text: Date of Application. 9th Apr., 1895
Complete Specification Left, 9th Jan., 1896-Accepted, 15th Feb., 1396
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Chlorine, and in the Treatment
of Bye-products of the said Manufacture.
We, JULIUS RASCHEN, Ph.D., (hemist, and JOHN BROCK, Director of The
United Alkali Company Limited, both of G 11 Exchange Buildings, Liverpool
in the County of Lancaster, do hereby declare the nature of this invention to be
as follows:-
This invention relates to the manufacture of chlorine from common salt or
potassium chloride by means of nitrates and sulphuric acid and to the more
economical utilization of the nitrogen compounds obtained as bye products.
We add an excess of sulphuric acid to an intimate mixture of 3 molecular
proportions of sodium chloride and one molecular proportion of sodium nitrate.
When the first, rather violent, reaction has ceased we apply heat to complete the
decomposition.
The escaping gases nitrosyl chloride, chlorine and a small amount of hydrochloric
acid gas are passed through strong sulphuric acid, which decomposes the nitrosy
chloride with formation of nitroso sulphuric acid and hydrochloric acid gas, which
latter escapes together with the chlorine gas, from which it may be separated by
condensation with water. The chlorine thus purified may then be utilised for the
manufacture of bleaching powder or in any other way.
The nitroso sulphuric acid formed in the process remains dissolved in the sulphuric
acid, and we prefer to make the solution as rich in nitrososulphuric acid as possible.
This solution we treat with sodium chloride, when nitrosyl-chloride is again evolved
with some hydrochloric acid gas. To this gaseous mixture we add hydrogen gas in
a suitable apparatus using rather more hydrogen than is theoretically required for
the conversion of the nitrosyl chloride into ammonium chloride and water according
to the equation
NOCI CH NH
NHỌC! ! HO.
The mixture of hydrogen and nitrosyl chloride we pass through a tube filled
with platinised asbestos from which all atmospheric oxygen has been displaced by
means of inert gases such as nitrogen or carbonic acid gas. The platinised asbestos.
heated to the requisite temperature causes a reaction between the nitrosyl chloride
and the hydrogen gas, whereby ammonia, hydrochloric acid, and aqueous vapour
are produced. The mixture of these gases is then passed into a suitable chamber
or series of chambers, kept at a temperature sufficiently low to allow the ammonia
and the hydrochloric acid to combine and to deposit as solid ammonium chloride,
yet sufficiently high to prevent the condensation of any of the aqueous vapour
within the chamber, but to cause it to pass on to be afterwards condensed in an
ordinary coke tower together with the excess of hydrochloric acid which was
originally contained in the nitrosyl chloride.
The hydrogen gas used in this process may be obtained from any convenient
source and may be contaminated with inert gases such as nitrogen carbonic acid or
hydrocarbons, but it must be free from oxygen gas. Illuminating gas rich in
hydrogen may be used, or water gas, but we prefer to obtain the hydrogen by
passing steam over incandescent coke.
The mixture of hydrogen and nitrosyl chloride we pass through a tube filled
with platinised asbestos from which all atmospheric oxygen has been displaced by
means of inert gases such as nitrogen or carbonic acid gas. The platinised asbestos.
heated to the requisite temperature causes a reaction between the nitrosyl chloride
and the hydrogen gas, whereby ammonia, hydrochloric acid, and aqueous vapour
are produced. The mixture of these gases is then passed into a suitable chamber
or series of chambers, kept at a temperature sufficiently low to allow the ammonia
and the hydrochloric acid to combine and to deposit as solid ammonium chloride,
yet sufficiently high to prevent the condensation of any of the aqueous vapour
within the chamber, but to cause it to pass on to be afterwards condensed in an
ordinary coke tower together with the excess of hydrochloric acid which was
originally contained in the nitrosyl chloride.
The hydrogen gas used in this process may be obtained from any convenient
source and may be contaminated with inert gases such as nitrogen carbonic acid or
hydrocarbons, but it must be free from oxygen gas. Illuminating gas rich in
hydrogen may be used, or water gas, but we prefer to obtain the hydrogen by
passing steam over incandescent coke.

page_text: The hydrochloric acid obtained by condensation with water in the above process
may be again used for the manufacture of chlorine by means of nitric acid and the
nitrosyl chloride obtained be treated as described.
Dated this 9th day of April 1895.
Improvements in the Manufacture of Chlorine, and in the Treatment
of Bye-products of the said Manufacture.
We JULIUS RASCHEN, Ph.D. Chemist and JOHN BROCK, Director of The
United Alkali Company, Limited, both of G 11 Exchange Buildings, Liverpool
in the County of Lancaster, 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 :—
This invention relates to the manufacture of chlorine from common salt, or
potassium chloride, by means of nitrates and sulphuric acid, and to the more
economical utilization of the nitrogen compounds obtained as bye-products.
We add an excess of sulphuric acid to an intimate mixture of 3 molecular
proportions (or 175.5 parts by weight) of sodium chloride, and one molecular
proportion (or 85 parts by weight) of sodium nitrate. When the first, rather
violent, reaction has ceased, we apply heat to complete the decomposition.
The escaping gases, nitrosyl chloride, chlorine, and a small amount of hydro-
chloric acid gas, are passed through strong sulphuric acid, which decomposes the
nitrosyl chloride with the formation of nitroso sulphuric acid and hydrochloric
acid gas, which latter escapes, together with the chlorine gas, from which it may
be separated by condensation with water. The chlorine thus purified may then
be utilized for the manufacture of bleaching powder, or in any other way.
The nitroso sulphuric acid formed in the process remains dissolved in the
sulphuric acid, and we prefer to make the solution as rich in nitroso sulphuric acid
as possible. This solution we treat with sodium chloride, when nitrosyl chloride is
again evolved with some hydrochloric acid gas. To this gaseous mixture we add
hydrogen gas, in a suitable apparatus, using rather more hydrogen than is
theoretically required for the conversion of the nitrosyl chloride into ammonium
chloride and water according to the equation
The mixture of hydrogen and nitrosyl chloride we pass through a tube or vessel
filled with or containing platinised asbestos from which all atmospheric oxygen
has been displaced which may be done by means of inert gas, such as nitrogen, or
carbonic acid gas. The platinized asbestos, heated to the requisite temperature,
causes a reaction between the nitrosyl chloride and the hydrogen gas, whereby
ammonia, hydrochloric acid, and aqueous vapour, are produced. The mixture of
these gases is then passed into a suitable chamber, or series of chambers, kept at a
temperature sufficiently low to allow the ammonia and the hydrochloric acid to
combine and to deposit as solid ammonium chloride yet sufficiently high, (say
about 100° Centigrade,) to prevent the condensation of any of the aqueous vapour
within the chamber, but to cause it to pass on to be afterwards condensed (which
may take place in an ordinary coke tower) together with the excess of hydro-
chloric acid which was originally contained in the nitrosyl chloride.
The hydrogen gas used in this process may be obtained from any convenient
source, and may be contaminated with inert gases, such as nitrogen, carbonic acid,

page_text: or hydrocarbons, but it must be free from oxygen gas. Illuminating gas rich in
Lydrogen or "water gas" may be used, but we prefer to obtain the hydrogen by
passing steam over incandescent coke.
A mixture of hydrochloric acid and nitric acid in suitable proportions may of
course be heated in place of the materials first mentioned and therefore the hydro-
chloric acid obtained by condensation with water in the above process may be
again used for the manufacture of chlorine by means of nitric acid the nitrosyl
chloride obtained, being treated as hereinbefore described.
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 :-
:―
1. In the manufacture of chlorine, as described, treating the bye-product nitroso-
sulphuric acid with common salt, mixing the nitrosyl chloride thus obtained with
hydrogen gas, (or gases containing it) and passing this mixture over platinised
asbestos at an elevated temperature for the purposes set forth and substantially as
hereinbefore described.
2. In the manufacture of chlorine as described and recovering the nitrogen.
compounds in the form of ammonia or its salts treating the nitroso sulphuric acid
with common salt, mixing the evolved gas with hydrogen (or gases containing it).
and passing the gaseous mixture over platinised asbestos at an elevated temperature.
substantially as hereinbefo e described.
Dated this 0th day of January 1896
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents..