AN IMPROVED PROCESS FOR THE RECOVERY OF VARIOUS MATTERS CONTAINED IN SALINE LIQUORS PRODUCED IN THE MANUFACTURE OF SOAP
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "AN IMPROVED PROCESS FOR THE RECOVERY OF VARIOUS MATTERS
CONTAINED IN SALINE LIQUORS PRODUCED IN THE MANUFACTURE OF SOAP."
A communication from abroad by Constant Victor Clolus, of Paris, France.
PROVISIONAL SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents on the 16th February 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS FOR THE RECOVERY
OF VARIOUS MATTERS CONTAINED IN SALINE LIQUORS PRODUCED IN THE
MANUFACTURE OF SOAP." [A communication from abroad by Constant Victor
Clolus, of Paris, France].
This Invention relates to an improved process or processes for treating the saline
waters or liquors from soap-manufactories, to extract therefrom various salts,
glycerine, and fatty matters. This water or liquor is produced in the manufacture
of all kinds of hard soap made with neutral fatty matters, and contains in greatly
varying proportions, water, glycerine, caustic soda, carbonate of soda, sometimes
sulphates and salts of potash, and always a small quantity of more or less oxidized
fatty acid.
According to this Invention, in order to effect a separation of these various bodies
for commercial purposes, and especially to extract the glycerine therefrom, I first
saturate this water or liquor when cold with hydrochloric acid till it is neutralized.
The solids are precipitated and collected; the neutral clear liquid is evaporated in
any suitable heating apparatus.
By degrees, as the evaporation proceeds, the salt is precipitated and is removed,
subjected to the action of a turbine and washed; in most cases this salt is bay or
marine salt in a nearly pure state. The evaporation is arrested when the liquid has
arrived at a density of about 32° Beaumé; at this degree the glycerine contained in
Price 1

page_text: the
soap water still contains considerable quantities of salt in solution, the greater
part of which is eliminated by the following treatment, that is to say, the glycerine
liquid at about 32° Beaumé, is poured into any suitable reservoir, and heated air is
blown into it, or the liquid is otherwise heated and cold air blown therein. The
air so heated or heated by the glycerine itself gradually eliminates the last traces
of water in the glycerine, and salt is constantly precipitated, as the latter is very
slightly soluble in anhydrous glycerine. To eliminate the water evaporation in vacuo
might also be effected, but would be more expensive. As the final result, highly
concentrated glycerine mixed with salt crystals is obtained. A turbine is used for
eliminating the salt, which is systematically washed, and the water used for the
washing is again treated.
It is obvious that instead of effecting the separation of the salt by means of a
turbine, the same result might also be obtained by dialysis.
The glycerine thus purified by one or the other of these two processes contains
only a very small quantity of bay or marine salt in solution, and may be distilled.
I may also adopt another method of working when I wish to obtain the
carbonated or caustic salts of soda in the condition of carbonates, instead of trans-
forming them into chlorides by means of hydrochloric acid. For this purpose I
evaporate the water as it is obtained from the soap works, introducing into the
same carbonic acid so as to carbonate the caustic soda therein contained. When
the liquor indicates about 25°, I cool the same and introduce therein an excess of
carbonic acid; bi-carbonate of soda is thereby formed, which is only slightly
soluble, especially in a glycerine solution of salt. The greater part is precipitated
and is eliminated by means of a turbine. The bicarbonate is transformed into
carbonate by calcining. The glycerine liquid which leaves the turbine is treated as
herein before indicated.
If it is desired to obtain glycerine more free from salt, the operation is as
follows, viz-To the glycerine, concentrated by air blown into it or in vacuo,
hydrochloric acid is added in excess, either in a gaseous state or as a liquid
concentrated to, say, 22° Beaumé. Bay or marine salt being almost insoluble in an
excess of hydrochloric acid will be precipitated in fine crystals and is eliminated by
means of a turbine. The excess of hydrochloric acid then contained in the glycerine
is eliminated either by blowing air into the same or by an excess of oxide of lead.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
16th August 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "AN IMPROVED PROCESS FOR THE
RECOVERY OF VARIOUS MATTERS CONTAINED IN SALINE LIQUORS PRODUCED IN
THE MANUFACTURE OF SOAP." A communication from abroad by Constant Victor
Clolus, of Paris, France.
This Invention relates to an improved process for treating the saline waters or
liquors from soap manufactories, to extract therefrom various salts, glycerine, and
fatty matters. These waters or liquors are produced in the manufacture of all
kinds of hard soap, made with neutral fatty matters, and contain in greatly varying
proportions, water, glycerine, caustic soda, carbonate of soda, sometimes sulphates
and salts of potash, and always a small quantity of more or less oxidised fatty
acid.
According to this Invention in order to effect a separation of these various bodies
for commercial purposes, and especially to.extract the glycerine therefrom, I first
saturate the water or liquor when cold with hydrochloric acid until it is neutralized.
The solids are precipitated and collected. The neutral clear liquid is evaporated in
any suitable heating apparatus.
By degrees as the evaporation proceeds the salt is precipitated and removed,
subjected to the action of a turbine, and washed. In most cases this salt is bay or
marine salt in a nearly pure state. The evaporation is arrested when the liquid has
arrived at a density of about 32° Baumé. At this degree the glycerine contained
in the soapy water still contains a considerable quantity of salt in solution, the
greater part of which is eliminated by the following treatment, that is to say, the
glycerine liquid at about 32° Baumé, is poured into any suitable reservoir, and
heated air is blown into it; or the liquid is otherwise heated and cold air blown
therein. The hot air or air heated by the glycerine gradually eliminates the last
traces of water in the glycerine, and there will be a continued precipitation of the
salt as the latter is very slightly soluble in anhydrous glycerine. The water may
be removed by evaporatian in vacuo. but the cost would be thereby increased. As
the final result I obtain highly concentrated glycerine mixed with salt crystals. A
turbine is used for removing the salt, which is washed, and the water used for
the washing is again used in the process.
It is obvious that instead of effecting the separation of the salt by means of a
turbine, the same result might also be obtained by dialysis.
The glycerine thus purified contains only a very small quantity of bay or marine
salt in solution, and may be distilled.
I may also adopt another method of working when I wish to obtain the
carbonated or caustic salts of soda in the condition of carbonates, instead of
transforming them into chlorides by means of hydrochloric acid. For this purpose
I evaporate the water as it is obtained from the soap-works, introducing into the
same carbonic acid so as to carbonate the caustic soda therein contained. When
the liquor indicates about 25° Baumé, I cool the same and introduce therein an
excess of carbonic acid; bicarbonate of soda is thereby formed, which is only
slightly soluble especially in a glycerine solution of salt. The greater part is
precipitated and is eliminated by means of a turbine. The bicarbonate is trans-
formed into carbonate by calcination. The glycerine liquid which leaves the turbine
is treated as hereinbefore indicated.
If it is desired to obtain glycerine more free from salt, the operation is as
follows, viz-To the glycerine (concentrated by air blown into it or in vacuo),

page_text: hydrochloric acid is added in excess, either in a gaseous condition or as a liquid
concentrated to say 22° Baumé. Bay or marine salt being almost insoluble in an
excess of hydrochloric acid will be precipitated in fine crystals, and is removed by
means of a turbine. The excess of hydrochloric acid then contained in the glycerine
is eliminated either by blowing air into the same, or by an excess of oxide of lead.
In some cases I may use the hydrochloric acid and carbonic acid simultaneously.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
The above described process of treating the saline water or liquor from soap-
manufactories, to extract therefrom the salts, glycerine, and fatty matters, such
process comprising,-
1. The treatment of the aforesaid water or liquor by hydrochloric acid or
carbonic acid or by both simultaneously, for the purpose of separating therefrom
the salts and fatty matters contained therein, and for obtaining water containing
glycerine as above set forth.
2. The subsequent treatment of the aforesaid water or liquor by frictional
evaporation, as and for the purpose specified.
3. The introduction of air for de-hydrating the glycerine, for the purpose of
precipitating the remaining salts, as above set forth.
4. The precipitation of the bay or marine salt in the glycerine by means of
hydrochloric acid, as above set forth.
•
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Sixteenth day of August, in the year of our Lord One
thousand eight hundred and eighty one.
W ROD LAKE. (L.S.)
ROB.