Improvements in the Production of Chlorine.
Year: 1891

page_text: Date of Application, 15th Apr., 1891
Complete Specification Left, 15th Dec., 1391-Accepted, 16th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Production of Chlorine.
I JULES KOLB, Managing Director of La Société Anonyme des Manufactures
de Produits Chimiques du Nord, of Lille (Nord) France do hereby declare the
nature of this invention to be as follows:-
;―
This invention relates to the production of chlorine in the Deacon apparatus;
and consists in a process whereby the whole of the gases produced by the decom-
position of the salt may be employed.
The manufacture of chlorine by the Deacon process has hitherto necessitated the
employment of pure hydrochloric acid containing only traces of sulphurous and
sulphuric acids, such as that which is produced by the decomposition of sea salt or
rock salt by sulphuric acid in lead or cast iron pans, and it has not been possible
to use the gases resulting from the second stage of the operation which is conducted
at a very high temperature in ovens heated to redness, as these gases, termed
gases of calcination, being charged with sulphurous and sulphuric acids, soon
render the decomposing material useless. It has therefore been necessary to
separate as completely as possible, the gases produced in the two stages of the
operation and the conversion into chlorine of those resulting from the second stage
has been entirely abandoned. The gases from the pans themselves contain a
certain proportion of sulphurous and sulphuric acids, especially when the pans are
made of cast iron, either in consequence of the action of the iron upon the sulphuric
acid or of the defective working of the dampers separating the pans from
the ovens.
The present invention has for its object to purify these gases by passing them
through externally heated iron cylinders or towers filled with fragments of porous
brick impregnated with chloride of magnesium and chloride of copper.
In the
presence of the nascent chlorine formed by the contact of the hydrochloric acid
with the coppery brick, the sulphurous acid is oxidized to sulphuric acid which,
together with that already existing in the gas, is retained by the bricks in the
form of sulphate of magnesium which salt is fixed at the temperature at which the
reaction takes place.
This purifying process being inapplicable to the gases of calcination, which
are too-highly charged with sulphurous and sulphuric acids, they are purified
by means of chloride of sodium which, as has been shewn by Hargreaves,
decomposes in presence of sulphurous acid and oxygen, with or without water,
according to one of the following equations ;-
;-
NaCl + SO +20= NaO, SO³ + CI.
NaCl + SQ + 0 + HO= NaO, SO' + HCl.
The sulphuric acid in presence of chloride of sodium also yields sulphate of
sodium and hydrochloric acid or chlorine, according to whether it is hydrated or
anhydrous. Thus, on contact with the chloride of sodium, the sulphurous and
sulphuric acid gases, in presence of oxygen, form sulphate of sodium and hydro-
chloric acid or chlorine according as aqueous vapor is present or not.
The having collected sonarately or together.

page_text: cylinder which was most recently charged, whence the gases, which now only
contain traces of sulphurous and sulphuric acids, mixed with hydrochloric acid and
air, are conducted to the top of the last cylinder, which is filled with broken porous
bricks impregnated with chloride of magnesium and chloride of copper whereby
their purification is completed at same time that a part of the hydrochloric acid is
converted into chlorine.
The purifiers have grated bottoms, upon which the materials are supported, and
louvres, for the distribution of the gases, external heating flues, charging and
discharging doors, and pipes connecting the various purifier cylinders all of which
may be arranged and modified as may be required.
Dated this 15th day of April 1891.
J. KOLB.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Production of Chlorine.
I, JULES KOLB, Managing Director of La Société Anonyme des Manufactures
de Produits Chimiques du Nord, of Lille (Nord) France, 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 production of chlorine in the Deacon apparatus;
and consists in a process whereby the whole of the gases produced by the decom-
position of the salt may be employed.
The manufacture of chlorine by the Deacon process has hitherto necessitated the
employment of pure hydrochloric acid containing only traces of sulphurous and
sulphuric acids such as that which is produced by the decomposition of sea-salt or
rock-salt by sulphuric acid in lead or cast iron pans, and it has not been possible to
use the gases resulting from the second stage of the operation which is conducted
at a very high temperature in ovens heated to redness, as these gases, termed guses
of calcination, being charged with sulphurous and sulphuric acids, soon render the
decomposing material useless. It has therefore been necessary to separate as
completely as possible, the gases produced in the two stages of the operation and
the conversion into chlorine of those resulting from the second stage has been
entirely abandoned. The gases from the pans themselves contain a certain
proportion of sulphurous and sulphuric acids, especially when the pans are
made of cast iron, either in consequence of the action of the iron upon the
sulphuric acid or of the defective working of the dampers separating the pans
froin the ovens.
The present invention has for its object to purify these gases by passing them
through externally heated iron cylinders or towers filled with fragments of porous
brick impregnated with chloride of magnesium and chloride of copper. In the
presence of the nascent chlorine formed by the contact of the hydrochloric acid
with the coppery brick, the sulphurous acid is oxidized to sulphuric acid which,
together with that already existing in the gas, is retained by the bricks in the form
of sulphate of magnesium, which salt is fixed at the temperature at which the
reaction takes place.
This purifying process being inapplicable to the gases of calcination, which are
too-highly charged with sulphurous and sulphuric acids, they are purified by means
of chloride of sodium which, as has been shewn by Hargreaves, decomposes in
presence of sulphurous acid and oxygen, with or without water, according to one of
the following equations ;-

page_text: The sulphuric acid in presence of chloride of sodium also yields sulphate of
sodium and hydrochloric acid or chlorine, according to whether it is hydrated or
anhydrous. Thus, on contact with the chloride of sodium, the sulphurous and
sulphuric acid gases, in presence of oxygen, form sulphate of sodium and hydro-
chloric acid or chlorine according as aqueous vapor is present or not.
In carrying out this purification after having collected separately or together the
gases produced in the pans and the calcination gases from the ovens, they are
conducted into a series of iron cylinders or towers externally heated by means of
flues and all, with the exception of one, filled with lumps of rock salt or agglomerated
sea salt. The guses pass from one to the other of the cylinders, entering at the
top of that one which was first charged, passing out at the bottom, and entering at
the top of the next one, and so on in succession, until they pass out at the bottom
of the cylinder which was most recently charged, whence the gases, which now
only contain traces of sulphurous and sulphuric acids, mixed with hydrochloric
acid and air are conducted to the top of the last cylinder, which is filled with
broken porous bricks impregnated with chloride of magnesium and chloride of
copper whereby their purification is completed at same time that a part of the
hydrochloric acid is converted into chlorine.
The purifiers have grated bottoms, upon which the materials are supported, and
louvres for the distribution of the gases, external heating flues, charging and
discharging doors, and pipes connecting the various purifier cylinders all of which
may be arranged and modified as may be required.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
The herein described process of eliminating the sulphurous and sulphuric acid
gases contained in the hydrochloric acid gas resulting from the decomposition of salt
by causing said gas to pass through a series of externally-heated iron cylinders or
towers filled with lumps of rock-salt or agglomerated sea-salt and afterwards
through a cylinder containing broken porous bricks impregnated with chloride of
megnesium, or through one or other of these materials as the case may be, substan-
tially as specified.
Dated this 15th day of December 1801
J. KOLB.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.