IMPROVEMENTS IN THE MANUFACTURE OF GLYCERINE
Year: 1883

page_text: LETTERS PATENT to John Imray of N° 28 Southampton Buildings, Chancery
Lane, in the County of Middlesex for an Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF GLYCERINE" communicated to him from abroad by
Ivar Axel Ferdinand Bang of Paris in the Republic of France
PROVISIONAL SPECIFICATION left by the said John Imray at the Office
of the Commissioners of Patents on the 26th September 1883.
"
JOHN IMRAY of N° 28 Southampton Buildings, Chancery Lane in the County
of Middlesex IMPROVEMENTS IN THE MANUFACTURE OF GLYCERINE" [com-
municated to him from abroad by Ivar Axel Ferdinand Bang of Paris in the
Republic of France]
Glycerine, as it is obtained by either of the usual processes of saponification or
acidification, contains numerous impurities, such as chloride of calcium, magnesium
or sodium, sulphates, traces of copper or iron, organic colouring matters or fatty and
nitrogenous substances, and particularly compounds of lime with volatile organic
acids, which acids, (such for instance as butyric acid), as well as their lime salts,
have a very disagreable smell and flavour. The object of this invention is to get
rid of these impurities by a simple and inexpensive treatment applicable to either
the saponification or to the acidification process.
For obtaining in the first place the glycerine liquor, the fats to be treated are
carefully washed to get rid of all soluble salts, the caustic lime to be employed for
saponification is also washed with pure, and finally with distilled water, and the
limestone to be used for neutralising the product of the acidification process is
selected quite free from chlorides. All the water employed in the process should
be distilled.
In operating by saponification, the glycerine liquor is separated from the
decomposed fat, and cooled so that the principal part of the fatty acid becomes
separated in the form of an emulsion. The liquor thus cleared is run into an
evaporating vessel, preferably lined with lead or tin, and during evaporation, a
small quantity of white stearic acid is added. This has the effect of decomposing
the lime salts of the volatile organic acids, liberating the acids which escape with

page_text: the vapour. As a stearate of lime is formed, care should be taken to continue
adding, during the evaporation, small quantities of stearic acid whenever the scum
tends to solidify. The stearate has the effect of separating the various impurities.
After evaporating till the glycerine liquor has a strength of 22° or 24° Beaumé at
about 60° Fahr, it is allowed to cool slowly, when the glycerine is found very clear
and pure and of good flavour under the crust of stearic acid and stearate of lime,
and it may then be concentrated to 28% or 30° Beaumé. When it is intended for
dynamite, it is concentrated to 30° Beaumé, while adding a very small percentage
of pure animal charcoal, and is filtered. When the glycerine is required very
white and pure for food purposes, a little more charcoal should be added, and
the traces of lime should be precipitated by any suitable reagent.
In operating by acidification, the liquor is neutralised by lime or its carbonate,
chemically pure, and the clear neutral liquor is then evaporated with addition of
stearic acid as above described, and also of small quantities of finely pulverised
pure carbonate of baryta, these reagents acting with the sulphate of lime in the
liquor to separate the volatile acids and other impurities. Stearate of baryta, kept
fused in excess of stearic acid, may be used instead of the carbonate of baryta.
After evaporation, the product is treated in the same way as that obtained by
saponification.
In order to bleach more completely, a reducing hydrogenating substance may be
added during evaporation. A suitable substance for this purpose is zinc powder,
obtained by distillation of zinc, the proportion required being very small, about one
to a thousand parts of the glycerine liquor,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Imray in the Patent Office on the 24th March 1884.
บ
JOHN IMRAY of N° 28 Southampton Buildings, Chancery Lane, in the county
of Middlesex "IMPROVEMENTS IN THE MANUFACTURE OF GLYCERINE
A com-
munication to. me from abroad. by Ivar Axel Ferdinand Bang of Paris in the
republic of France.
Glycerine, as it is obtained by either of the usual processes of saponification or
acidification, contains numerous impurities, such as chloride of calcium, magnesium
or sodium, sulpbates, traces of iron or copper, organic coloring matters or fatty and
nitrogenous substances, and particularly compounds of lime with volatile organic
acids, which acids such for instance, as butyric acid, as well as their lime salts, have
a very disagreeable smell and flavor. The object of this invention is to get rid
of these impurities by a simple and inexpensive treatment, applicable to either the
saponification or to the acidification process.
For obtaining in the first place the glycerine liquor, the fats to be treated are
carefully washed to get rid of all soluble salts; the caustic lime to be employed for
saponification is also washed with pure, and finally with distilled water; and the
limestone to be used for neutralising the product of the acidification process is
selected quite free from chlorides. All the water employed in the process should
be distilled.
In operating by saponification, the glycerine liquor is separated from the
decomposed fat, and cooled, so that the principal part of the fatty acid becomes
separated in the form of an emulsion. The liquor thus cleared is run into an
evaporating vessel, preferably lined with lead or tin and during evaporation, a
small quantity of white stearic acid is added. This has the effect of decomposing
the lime salts of the volatile organic acids, liberating the acids which escape with
the vapor. As a stearate of lime is formed, care should be taken to continue
adding, during the evaporation, small quantities of stearic acid whenever the scum
tends to solidify. The stearate has the effect of separating the various impurities.
After evaporating till the glycerine liquor has a strength of 22° or 24° Beaumé, at
about 60° Fahr. it is allowed to cool slowly, when the glycerine is found very clear
and pure and of good flavor, under the crust of stearic acid and stearate of lime,
and it may then be concentrated to 28° or 30° Beaumé. When it is intended for
dynamite, it is concentrated to 30° Beaumé, while adding a very small percentage
of pure animal charcoal, and is filtered. When the glycerine is required very
white and pure for food purposes, a little more charcoal should be added, and the
traces of lime should be precipitated by any suitable reagent.
In operating by acidification, the liquor is neutralised by lime or its carbonate,
chemically pure, and the clear neutral liquor is then evaporated with addition of
stearic acid, as above described, and also of small quantities of finely pulverised
pure carbonate of baryta, these reagents acting with the sulphate of lime in the
liquor to separate the volatile acids and other impurities. Stearate of baryta, kept
fused in excess of stearic acid, may be used instead of the carbonate of baryta.
After evaporation, the product is treated in the same way as that obtained by
saponfication.
In order to bleach more completely, a reducing hydrogenating substance may be
added during evaporation. A suitable substance for this purpose is zinc powder,
obtained by distillation of zinc, the proportion required being very small, about
1 to 1000 parts of the glycerine liquor.

page_text: Having thus described the nature of this invention and in what manner the
same is to be performed, as communicated to me by by foreign correspondent, I
claim, in the manufacture of glycerine,―
First The use of chemically pure lime and limestone with distilled water so as
to obtain glycerine liquor free from lime salts suluble in mineral acid.
Second: The addition of stearic acid or its analogues, under heat, to decompose
lime salts and absorb colouring matters.
Third: The addition of zinc powder or equivalent hydrogenating substance, to
bleach the glycerine.
In Witness whereof I the said John Imray have hereunto set my hand and
seal this Twenty Fourth day of March in the year of our Lord, one thousand
eight hundred and eighty-four.