A NEW METHOD OF SEPARATING SUGAR FROM MOLASSES STRONTIA AT LOW TEMPERATURES AND SIRUPS BY THE " PRODUCTION OF SACCHARATE
Year: 1882

page_text: LETTERS PATENT to Professor Doctor Carl Scheibler of Berlin, Prussia,
German Empire for an invention of " A NEW METHOD OF SEPARATING SUGAR
FROM
MOLASSES
STRONTIA AT LOW TEMPERATURES
AND SIRUPS BY THE
"
PRODUCTION
OF
SACCHARATE
OF
PROVISIONAL SPECIFICATION left by the said Professor Doctor Carl
Scheibler at the Office of the Commissioners of Patents on the 11th May
1882.
Professor Doctor CARL SCHEIBLER of Berlin, Prussia, German Empire, NEW
METHOD OF SEPARATING SUGAR FROM MOLASSES AND SIRUPS BY THE PRODUCTION
OF SACCHARATE OF STRONTIA AT LOW TEMPERATURES.
My Invention substantially consists in the separation of sugar from molasses
and sirup by causing the sugar to combine at a comparatively low temperature
with hydrate of strontia to monosaccharate of strontia from which the pure sugar
may readily be obtained.
In carrying out the invention, it has been found advantageous to use one part
by weight of hydrate of strontia to one part by weight of sugar contained in the
molasses or sirup; but this proportion need not be strictly adhered to. The
hydrate of strontia is dissolved in about three times its weight of water having
nearly the boiling-temperature, and this solution, or a solution of the said hydrate
otherwise prepared and having the same strength, is added, while hot, to the cold
molasses, &c. Or, the molasses, &c., is mixed with the water, the mixture heated
to about 80 degr. centigr., and the crystallized hydrate of strontia added in solid
state, in order to be dissolved therein while the liquid is stirred. Another mode of
proceeding consists in introducing into the mixture of molasses, &c., with water;
anhydrous caustic strontia obtained from the calcining-furnace and finely powdered.
The same will be slaked in the liquide while the saccharate is formed.
In whichsoever manner the process may have been carried out, the liquor
containing the strontic saccharate is either allowed to cool spontaneously, or it is

page_text: refrigerated artificially. During this cooling no saccharate separates out; on the
contrary, strontic hydrate in unchanged condition would crystallize out from the
liquor when cold and if left undisturbed. But if the liquor is stirred continuously,
or from time to time, and especially if a small quantity of saccharate from a
previous process is distributed therein, the separation of the saccharate commences,
and is generally finished in 12 to 24 hours. The liquor has then become a stiff
mass, which, when being stirred, reliquidates to a thick pulp. The latter consists
of the saccharate, with which may be mixed crystals of hydrate of strontia, and
which is saturated with a mother-lye consisting of the solution of foreign
substances together with strontia. The saccharate is separated from the mother-
lye in any suitable manner and is thereupon lixivated by means of water or by a
cold saturated solution of hydrate of strontia.
The monosaccharate of strontia not being quite insoluble, a part thereof remains
in the mother-lye and in the lixivating-liquid. For obtaining this part, or the
greater portion thereof, the lye and the lixivating-liquid are mixed with
crystallized hydrate of strontia in excess and boiled until the sugar has separated
out together with strontia in the form of bibasic saccharate. The lye resulting
from this process having been drawn off, the remaining bibasic saccharate is utilized
by being added to the hydrate of strontia employed for producing monosaccharate
from a new portion of molasses.
From the purified monosaccharate the sugar may be obtained: firstly, by
decomposing by means of carbonic acid the saccharate stirred up in water;
secondly, by employing the same for defecating the juice of beet roots, or, thirdly,
by dissolving the saccharate in water at a temperature somewhat below the boiling-
point and allowing to cool, whereupon a part of the hydrate of strontia will
crystallize out, and by precipitating the remaining part of the strontia by carbonic
acid.
The pure solutions of sugar are finally treated according to the modes of operation
ordinarily employed in sugar-manufactories.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Professor Doctor Carl Scheibler in the Great Seal Patent Office
on the 2nd November 1882.
Professor Doctor CARL SCHEIBLER, of Berlin, Prussia, German Empire.
"A NEW
METHOD OF SEPARATING SUGAR FROM MOLASSES AND SYRUPS BY THE PRODUCTION
OF SACCHARATE OF STRONTIA AT LOW TEMPERATURES
"
The process forming the subject matter of my invention is based on the following,
hitherto unknown chemical reactions.
When a solution of pure cane-sugar containing from 20 to 25 per cent of sugar
and heated to about 70 or 75 deg. centigr. is mixed, by constant stirring, with
hydrate of strontia (Sr. (OH), + 8 H,O) in the proportion of one molecule of sugar
to one molecule of the said hydrate, the latter dissolves completely and without
any separation of a saccharate; only the solution will generally be turbid from a
small quantity of carbonate of strontia unavoidably produced. If this liquid is
filtered in warm state and then allowed to cool while being prevented from
absorbing carbonic acid, a highly supersaturated solution of monobasic saccharate
of strontia will be formed. This monosaccharate is under ordinary conditions but
little soluble, as one part of the same requires 20 parts of water for dissolving it,
but the concentrated solution thereof prepared with hot water, may, after having
cooled down to the ordinary temperature of the air, subsist unchanged for a certain
time, and without any separation taking place. This supersaturated solution of
monosaccharate of strontia presents a peculiar difference of behaviour under
different circumstances. Either will hydrate of strontia in unchanged state
crystallize ont therefrom, or a gradual separating out of monobasic saccharate of
strontia takes place after some time. The crystallization or the separation may
be caused at will. Thus, if crystals of hydrate of strontia are thrown into the
supersaturated solution, the same substance will crystallize out unchanged,
whereas, when a small quantity of monosaccharate of strontia previously prepared
is added to the solution, the crystallization of a further quantity of this compound
is caused.
The said monosaccharate forms papillary masses, which grow into cauliflowerlike
aggregations subsequently dropping into fine-grained white powder, especially
when the mass is stirred or shaken.
The saccharate of strontia may also be formed in the "cold way" by introducing
the requisite quantity of hydrate of strontia in finely powdered state into a cold
solution of sugar and stirring constantly. The particles of strontia will, in this
case, gradually attract the sugar and unite with the same to form the mono-
saccharate. The process is to best advantage carried out by means of the fine
flour of strontia-crystals obtained by the so-called disturbed crystallization, which
takes place when a hot solution of strontia is constantly agitated by stirring until
it has become cold. The formation of the saccharate in the "cold-way is
particularly adapted when sugar is to be obtained from molasses produced in the
manufacture of raw sugar from cane, and containing a considerable quantity of
inverted sugar. This will be explained more fully hereafter.
""
Upon the described properties of the monosaccharate I have based the following
practical process of separating sugar in the form of saccharate of strontia from
molasses or syrup.
Supposing molasses containing 50 per cent of sugar were to be treated, then
1 kilogramm thereof, in which there will be 500 gramms of sugar, would require
389 grams of crystallized hydrate of strontia (Sr. (OH), + 8 H₂O) for converting
all the sugar into monosaccharate of strontia. It is however preferable to employ
so much more bydrate of strontia that the mother-lye or solution of foreign
substances remaining after the separation of the saccharate, may be saturated with
strontia. Instead of 389 gr. of the strontic crystals, 500 gr. or, in general, a
quantity equal to the weight of the surar, may be taken. There will then be

page_text: 1 molecule of sugar to 14 molecule of crystallized hydrate of strontia. This excess
of strontia is, however, not absolutely required, and it may be varied if desired.
Besides, it is to be observed that the same is subsequently reobtained, and does not
therefore constitute any loss.
For dissolving 500 gr. of hydrate of strontia, about 1500 gr. of water of a
temperature of 89 or 90 degr. centigr. are required. This leads to the following
simple proportion between the materials to be employed, and which has been
found advantageous in practice, but which nevertheless may be varied if required.
To each kilogr. of molasses is added, under constant stirring 1/2 kilogr. of crystals
of strontia previously dissolved in 1 kilogr. of water having a temperature some-
what below the boiling-point. When this mixture of the hot solution with the
cold molasses takes place, the latter speedily dissolves, while the temperature is
reduced, so that no bibasic saccharate of strontia (which is only formed at the
boiling temperature) is produced. The mixture remains clear, in so far as it is
not troubled by foreign substances separating out, such as carbonate and sulphate
of strontia, &c.
The molasses may also first be diluted with a certain quantity of water before
it is mixed with the hot strontic solution; or the molasses is mixed with the
whole quantity of water, the mixture heated to about 80 degr. centigr., and
subsequently the crystallized hydrate of strontia added thereto in solid state
while the liquid is stirred. The latter mode of operating would, however, require
the hydrate of strontia to be prepared in crystallized form, whereas in the other
method of proceeding, the hot lyes obtained by slaking recently-burnt strontia
anhydride, may be used directly, as the titre of these lyes may with facility be
determined by the areometer.
Another mode of proceeding consists in introducing into the mixture of molasses
with water anhydrous caustic strontia taken from the calcining furnace and finely
powdered; the same will be slaked in the liquid while the saccharate is formed.
In whichsoever manner the process may have been carried out, the liquor con-
taining the strontic saccharate is either allowed to cool spontaneously, or it is
refrigerated by any known artificial means or apparatus. During this cooling no
saccharate separates out; on the contrary, strontic hydrate in unchanged condition
would crystallize out from the liquor when cold and if left undisturbed. But if
the liquor is stirred continuously or from time to time, and especially if a small
quantity of saccharate from a previous process is distributed therein, the separation
of the saccharate immediately commences and continues, and is generally finished
in 12 to 24 hours. The liquor has then become a stiff mass, which, when being
stirred, reliquidates to a thick pulp. The latter consists of the saccharate, and,
in case strontic hydrate had been added in considerable excess, of crystals thereof,
both saturated with a mother-lye consisting of the solution of foreign substances
together with strontia. The saccharate is separated from the lye in any known
manner, i.e. by means of filter-presses, vacuum-filters, centrifugal machines, &c., and
is thereupon lixivated by means of water or by a cold saturated solution of
hydrate of strontia. In purified state the saccharate is perfectly white. From
the bibasic saccharate precipitated at the boiling-temperature, it differs substan-
tially by its far greater purity, which is such that, on being decomposed by carbonic
acid, it yields a completely colourless solution of sugar, which requires no filtration
over bone-charcoal.
As has already been observed, the saccharate produced at low temperatures is
not quite insoluble; for this reason not all the sugar contained in the molasses or
the syrup is obtained in the saccharate, but only a part thereof. Under the
above conditions, the yield will be from about 3/2 to 3/4 of the total amount of
sugar, while the rest remains in the mother-lye and in the lixivating-liquid. The
yield of saccharate, however, increases with the length of time which the mixture
is left to stand before the saccharate is seperated from the mother-lye. The said
yield of but about 2/3 to 3% of all the sugar contained in the molasses or the syrup,
is of course too low to allow the process to be claimed as a perfect one. But it is

page_text: not difficult to obtain the greater part of the remaining third or quarter also, so
that then the total quantity of sugar produced in the form of saccharate will
amount to about 96 or 97 per cent of the entire quantity present. For this
purpose I proceed as follows:
The lye separated from the saccharate, and to which is added the lixivating-
liquid, is mixed with crystallized hydrate of strontia and boiled, until the sugar
has separated out in the form of bibasic saccharate. The hydrate of strontia must,
in this case, be employed in such excess that the lye remaining after complete
separation of the bibasic saccharate, may contain a considerable quantity of
strontia. The precipitated bibasic saccharate need not, however, be freed_by
filtration from the mother-lye, nor lixivated, as this would be superfluous. But,
the boiling and stirring having been finished, it is allowed to settle, either in the
precipitating-vessel or in any other receptacle, whereupon the lye or solution of
foreign substances is separated from the precipitate in known manner by drawing
it off through a cock placed at a suitable height, or a syphon, &c. From this lye,
when cold, brown-coloured crystals of hydrate of strontia are deposited, which may
be reutilized in the following operations. The strontia then still contained in
solution, and part of which is combined with acids, having been precipitated by
means of carbonic acid and of an alkalic carbonate in the forin of carbonate of
strontia, the remaining mother-lye is utilized as manure or for the manufacture
of alkali salts, ammonia, &c.
The bibasic saccharate of strontia produced and still impregnated with mother-
lye, is utilized by being introduced into and mixed with a new quantity of molasses
for the purpose of separating out monosaccharate in a similar manner as hereinbefore
described in respect to to the hydrate of strontia. The bibasic saccharate, which
is yet hot, speedily dissolves in the cold molasses in consequence of the excess of
free sugar present in the latter. Hereafter the pulpy mixture, while being stirred,
is diluted with so much hot saturated solution of hydrate of strontia, that the
molecular proportion between the whole quantity of sugar (contained in the
molasses and in the bibasic saccharate) and the strontia may be again the same as
has herein before been given for the formation of monosaccharate, i.e. as 1 to
about. The mixture having become cold, the saccharate is separated out and
treated as has already been specified. It is evident that, in proceeding in this
manner, the sugar contained in the residual lyes of the monosaccharate, is not lost,
but that in the following operation it is returned into the circuit of operations as
bibasic saccharate, to be subsequently separated out as monosaccharate.. The
molasses thus undergoes a complete decomposition into nearly pure monosaccharate
on one hand, and a residual lye containing all foreign substances, on the other
hand, whereas the loss of sugar is but very slight.
From the purified monosaccharate the sugar may be obtained in different
manners:
Firstly, by decomposing, by means of carbonic acid, the saccharate stirred up in
water.
Secondly, by employing the saccharate in combination with a subsequent
process of saturation by carbonic acid for defecating the juice of beet-roots, or, for
carrying out a second purification thereof, after the same has been defecated by
lime and filtered.
Thirdly, by causing a part of the strontia to crystallize out as hydrate of strontia
(Sr (OH), +8 H₂O) and precipitating the residue of strontia hereafter remaining
in solution, by means of carbonic acid.
The latter method is based on the particular property of the monosaccharate
explained in the introduction, and according to which a part of the hydrate of
strontia crystallizes out from solutions of monosaccharate of strontia prepared
with hot (but not boiling) water and allowed to cool slowly and without being
stirred.
The pure solutions of sugar obtained by either of these methods, are treated
according to the modes of operation ordinairely employed in sugar manufactories,

page_text: Compared WICH GHe met
invented by me and described in the Specification of the English Patent
A.D. 1881 No. 331, and also in the " Neue Zeitschrift für Rübenzucker-
Industrie," Vol. VIII, P. 6-11, the method specified in the foregoing possesses the
following advantages:
1., It only requires simple refrigerating apparatuses (by preference apparatuses
with counter-currents) instead of the expensive cooling-rooms, cooling-boxes, and
cold-air machines, which were formerly wanted, as the material to be cooled is not
solid, but liquid.
2., Crystallizing vats for the hydrate of strontia are either not required at all,
or they may at least be considerably reduced in size, as, instead of the crystallized
hydrate, a hot saturated solution thereof may be employed immediately after
having been prepared.
3., About one third only of the quantity of hydrate of strontia formerly used, is
required.
4., In consequence hereof the losses of strontia are less.
5., The sugar obtained is purer.
Moreover the method presents the advantage:
G., that it may be applied to molasses obtained in the manufacture of raw sugar
from cane, or in the refining of such sugar, provided the amount of inverted sugar
contained in such molasses does not exceed certain limits. If the amount of
inverted sugar is not very considerable, it need not be taken into account at all, or,
When the
if preferred, it may be destroyed by boiling with lime or strontia.
quantity of inverted sugar is greater, the formation of monosaccharate in the
"cold way," as hereinbefore described, is employed, but in this case the yield of
sugar will ordinarily be less, as it is not always possible under such conditions to
separate bibasic saccharate at the boiling temperature from the residual lyes of the
monosaccharate, in order to utilize it in the following operation.
Having thus described the nature and object of my invention, and the manner
in which it is to be carried out in practice, I hereby claim as new and important
features of the same:
1., The method of producing monosaccharate of strontia in molasses and syrup
by introducing into the same while at a temperature below the boiling-point,
hydrate of strontia, by cooling the liquor, and by stirring it, in order to effect
the formation of the saccharate of strontia at a low temperature and the
separation thereof from the liquor, substantially as and for the purpose described.
2., In combination with the method of producing monosaccharate of strontia
in molasses and syrup by introducing into the same, while at a temperature below
the boiling-point hydrate of strontia, by cooling the liquor, and by stirring it,
the addition to the liquor of saccharate of strontia previously obtained, in order to
promote the separation of the saccharate of strontia formed in the liquor, as
herein before specified.
3., In combination with the process of producing monosaccharate of strontia in
molasses and syrup as hereinbefore described, the treatment of the mother-lye
resulting from such process, by adding thereto a further quantity of hydrate of
strontia and boiling, in order to produce bibasic saccharate of strontia, as and for
the purpose described.
In Witness whereof I, the said Carl Scheibler, have hereunto set my hand
and seal this twenty sixth day of October in the year of our Lord One
thousand eight hundred and eighty two.
DR. CARL SCHEIBLER (L.S.)