Process for the Extraction of Sugar from Molasses and other Saccharine Liquors by Means of Barium Hydroxysulphide, and the Regeneration of the latter from the By-products Produced.
Year: 1896

page_text: Date of Application, 24th Mar., 1895
Complete Specification Left, 28th Oct., 1896-Accepted, 9th Jan., 1897
PROVISIONAL SPECIFICATION.
Process for the Extraction of Sugar from Molasses and other
Saccharine Liquors by Means of Barium Hydroxysulphide, and
the Regeneration of the latter from the By-products Produced.
I, WALTHER FELD of Honningen af Rhein in den Silven in the German
Empire, Chemist do hereby declare the nature of this invention to be as follows:-
In the processes heretofore employed for extracting the sugar from molasses and
other saccharine liquors by means of caustic baryta the objection arises, that the
regeneration of the caustic baryta from the carbonate of baryta obtained by the
decomposition of the barium saccharate by means of carbonic acid, is attended
with difficulties. Under these circumstances it is of importance to the sugar
industries, to obtain a process which enables the barium compound which is used
for the extraction of the sugar, to be regenerated in a simple manner.
The present invention consists in the treatment of the molasses with barium
hydroxysulphide, and in the farther treatment of the vinasse lye containing the
barium hydroxysulphide remaining after precipitation of the barium saccharate.
for the regaining of the total amount of sulphur present in the form of sulphurous
acid. This latter then serves again for the regaining of the barium contained
in the precipitated barium saccharate as also that contained in the vinasse lye in
the form of barium sulphide. From the barium sulphide thus obtained the
regeneration of the barium hydroxysulphide originally employed can then be
effected by means which are capable of easy industrial application.
The said process is carried out in the following manner:
The barium saccharate precipitated from molasses or other saccharine liquors
by means of barium hydroxysulphide is decomposed by means of the sulphurous
acid obtained in another stage of the process, whereby, on the one hand,
saccharine solutions and on the other hand barium sulphite are obtained. The
decomposition of the barium saccharate can also be effected by means of carbonic
acid, in which case however the barium carbonate produced must be converted
into barium sulphite by a subsequent treatment with sulphurous acid.
Instead of decomposing the saccharate directly with sulphurous acid or with
carbonic acid and sulphurous acid it can also be treated with magnesium sulphite.
There are then formed baryta sulphite and insoluble magnesia hydrate together
with very pure sugar solution. But as the magnesia hydrate is separated with
difficulty from the sugar solution, the magnesia is converted by means of carbonic
acid into magnesia carbonate. The sludge of baryta sulphite and magnesia
carbonate can be readily filtered. After the separation of the sludge from the
juice the latter is treated in the known manner, while the constituents of the
sludge, namely magnesia carbonate and baryta sulphite must be separated from
each other. For this purpose the mixture is treated with the sulphurous acid
which is obtained in another stage of the process. The magnesia sulphite produced
is soluble and can therefore be readily separated from the insoluble baryta sulphite.
The magnesia sulphite is used over again for the decomposition of the saccharate.
The baryta sulphite obtained in the above described manner, is converted into
the barium hydroxysulphide.
The lye separated from the saccharate contains the barium which is not
precipitated as saccbarate and all the sulphur contained in the barium hydroxy-
sulphide originally employed. The object of the farther treatment of the lye is

page_text: to obtain, in addition to the vinasses, the sulphur contained therein, in the form
of sulphurous acid, in order, by means thereof, to convert the barium contained
in the saccharate, as, also in the vinasse lye, into a form which allows of the ready
regeneration of the barium hydroxysulphide employed.
The process can be carried out in two ways:
1. If a supply of sufficiently pure carbonic acid is available the lye is treated
with carbonic acid, whereby the sulphur contained in the lye is driven off in the
form of sulphuretted hydrogen, and the barium separates from the solution in the
form of harium carbonate.
The sulphuretted hydrogen is converted in the known manner into sulphurous
or sulphuric acid. The barium carbonate, after separation from the vinasse lye, is
converted into barium sulphite in the manner above described.
2. If the available carbonic acid should be so low in strength that the
sulphuretted hydrogen obtained thereby from the lye would not be of a com-
bustible nature, the hot lye is treated with magnesia sulphite. Insoluble barium
sulphite and magnesia hydrate are thus produced while the sulphur passes off as
highly concentrated sulphuretted hydrogen.
As the magnesia hydrate is filtered with difficulty, it is converted by the intro-
duction of carbonic acid into readily filterable magnesia carbonate for which
weak carbonic acid may be used. The sludge of magnesia carbonate and barium
sulphite is separated from the lye and, as described above in the treatment of the
saccharate the magnesia carbonate is converted into magnesia sulphite by means
of sulphurous acid, and owing to its soluble nature, it is readily separated from.
the barium sulphite and can be applied to its previous purpose again, while the
barium sulphite is subjected to farther treatment.
In place of sulphurous acid, sulphuric acid can also be used in the same manner
in the above processes. In this case there are produced sulphates instead of
sulphites of barium and magnesium, which can be employed in the same manner
as the sulphite compounds in the process.
The barium sulphite or barium sulphate obtained in any stage of the above
processes is heated to redness with charcoal. The melt obtained is treated with
water, whereby barium hydroxysulphide, that is, the substance employed for
precipitating the sugar, is again obtained.
The essential feature of the process, in addition to the novel application of the
magnesia sulphite or magnesia sulphate consists in that by the application of
sulphurous or sulphuric acid a closed circuit process is obtained, in which the
barium hydroxysulphide employed for the separation of the sugar, as also the
sulphurous or sulphuric acid employed, are regenerated.
The hereinbefore referred to barium hydroxysulphide has the composition
Ba(SH)(OH) and may also be considered as being a double compound of barium
hydroxide Ba(OH) with barium hydrosulphide Ba(SH)'.
Dated this 24th day of March 1896:
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process for the Extraction of Sugar from Molasses and other.
Saccharine: Liquors by Means of Barium Hydroxysulphide, and
the Regeneration of the latter from the By-products Produced..
B
I, WALTHER FELD, of Linz a Rhein, Villa Gereke", and formerly of
Honningen af Rhein in 'den Silven in the German Empire, Chemist, do hereby
declare the nature of this invention and in what manner the same is to be

page_text: performed to be particularly described and ascertained in and by the following
statement :-
In the processes heretofore employed for extracting the sugar from molasses
and other saccharine liquors by means of caustic baryta the objection arises,
that the regeneration of the caustic baryta from the carbonate of baryta
obtained by the decomposition of the barium saccharate by means of carbonic
acid, is attended with difficulties. Under these circumstances it is of importance
to the sugar industries, to obtain a process which enables the barium compound
which is used for the extraction of. the sugar, to be regenerated in such manner as
to allow the regaining of the originally used reagent, quantitatively. This has
not been possible hitherto, as the caustic baryta cannot be easily obtained from
the carbonate of baryta because the conversion may only be effected at a
relatively high temperature, and in the best case only 50 per cent. of the caustic
baryta may be regenerated by this way.
The present invention consists in the treatment of the molasses with barium
hydroxysulphide Ba(SH)(OH) obtained by lixiviation of barium sulphide with
water, and in the farther treatment of the vinasse lye containing the barium
hydrosulphide Ba(SH), remaining after precipitation of the barium saccharate,
for the regaining of the total amount of sulphur present in the form of sulphurous
acid. This latter then serves again for the regaining of the barium contained in
the precipitated barium saccharate as also that contained in the vinasse lye in
the form of barium sulphite. From the barium sulphite thus obtained the
regeneration of the barium hydroxysulphide originally employed can then be
effected by means which are capable of easy industrial application.
The said process is carried out in the following manner:
The barium saccharate BaO.CHO is precipitated from molasses or other
saccharine liquors by means of barium hydroxyeulphide Ba(SH)(OH). The
quantity of the reagent depends on the amount of the saccharose to be precipitated
and is to be chosen such that two molecules of barium hydroxysulphide Ba(SH)
(OH) may react with one molecule of sugar C₁₂HO11.
The reaction may be shown by the following equation:-
2 Ba(OH)(SH) + C₁₂HO₁
=
BaO.CgHgO +
Bariumhydroxysulphide Saccharose Bariumsaccharate
The reaction is carried out at a temperature between 60°-100° C. The
reagent may be used solid or in solution. In the latter case the concentration of
the solution has no great influence on the reaction, as the barium saccharate is
very little soluble in water.
The precipitated barium saccharate is separated from the lye in the ordinary
manner, by filtration &c., and is decomposed, after having been suspended in hot
or cold water, by means of the sulphurous or sulphuric acid obtained in another
stage of the process.
Hereby on the one hand saccharine solutions and on the other hand barium
sulphite or sulphate are obtained. The acids may be employed in a gaseous state
or in solution.
The quantity of sulphurous or sulphuric acid depends on the amount of the
barium saccharate to be decomposed, as one molecule of sulphurous or sulphuric
acid will be required for the decomposition of one molecule of barium saccharato,
corresponding to the equation:-
SO, BaO. C₁,Н„О₁ = С₁Н„О + BaSO,
+ C,H,On
H,SO, BaOCH,0₁₁
+ BaОС₁₂,0₁₁ = С₁НО₁ + BaSO4 + H₂O.

page_text: The formed barium sulphite BaSO, or sulphate BaSO, will be thrown down,
whereas the sugar liberated by the action of the sulphurous or sulphuric acid on
barium saccharate will be dissolved in the water.
The liquor now containing sugar, freed from the contaminations originally found
in the treated liquor molasses, will be filtered off from the barium sulphite and will
he boiled down for gaining the sugar in the solid state.
The decomposition of the barium saccharate can also be effected by means of
carbonic acid, in which case however the barium carbonate produced must be
converted into barium sulphite or sulphate by a subsequent treatment with
sulphurous or sulphuric acid obtained in another stage of the process.
These reactions may be shown by the following equations:-
The lye separated from the saccharate contains barium hydro sulphide Ba(SH),
so that half the quantity of barium and all the sulphur contained in the barium
hydroxy sulphide originally employed is found in the lye.
The process can be carried out in two ways:
1. If a supply of sufficiently pure carbonic acid is available, the lye is treated
with carbonic acid, whereby the sulphur contained in the lye is driven off in the
form of sulphuretted hydrogen, and the barium separates from the solution in the
form of barium carbonate.
The treatment of the lye with carbonic acid will be effected at ordinary as well
as at elevated temperature. The action of the carbonic acid on the baryum
hydrosulphide Ba(SH), corresponds to the equation :
Ba(SH), + H,O + CO, = BaCO, + 2 H,S.
The sulphuretted hydrogen is converted in the known manner into sulphurous
or sulphuric acid. The barium carbonate, is converted into barium sulphite in the
manner above described.
2. If the available carbonic acid should be so low in strength that the
sulphuretted hydrogen obtained thereby from the lye would not be of a combustible
nature, the hot lye is treated with magnesia sulphite or sulphate. Insoluble
barium sulphite BaSO, or sulphate BaSO, and magnesia hydrate Mg(OH), are
thus produced while the sulphur passes off as highly concentrated sulphuretted
hydrogen.
The reaction corresponds to the equation
Ba (SH), + MgSO, + 2 H,O= BaSO, + Mg (OH), + 2 H,S or: Ba (SH), +
MgSO, +2 H,O= BaSO4 + Mg (OH), +2 H,S.
The reaction takes place only with the hot lye and not at ordinary temperature.
As the magnesia hydrate is filtered with difficulty, it is converted by the
introduction of carbonic acid into readily filterable maguesia carbonate, for which
weak carbonic acid may be used. The sludge of magnesia carbonate and barium
sulphite or sulphate is separated from the lye and, as described above in the
treatment of the saccharate, the magnesia carbonate is converted into magnesia
sulphite or sulphate by means of sulphurous or sulphuric acid, and, owing to its
soluble nature, it is readily separated from the barium sulphite or sulphate and can
be applied to its previous purpose again, while the barium sulphite or sulphate is
subjected to further treatment.
In place of sulphurous acid, sulphuric acid can also be used in the same manner
in the above processes. In this case there are produced sulphates instead of,

page_text: sulphites of barium and magnesium, which can be employed in the same manner as
the sulphite compounds in the process.
The aim in the using of sulphurous or sulphuric acid in the treatment of the
barium compounds, is the gaining of a barium compound that may easily be
changed into that barium compound originally used for the precipitating of sugar,
namely bariumhydroxysulphide. The conversion of the barium sulphite or sulphate
into bariumsulphide BaS and-bariumhydroxysulphide is effected in the same manner
by heating to redness with charcoal. It is also to be assumed that this reaction
takes place with barium sulphite as with barium sulphate, in a very analogous way,
so that the sulphate and the sulphite are equivalent in their effect.
The barium sulphite or barium sulphate obtained in any stage of the above-
processes is heated to redness with charcoal. The melt obtained is treated with
water, whereby barium hydroxysulphide, that is, the substance employed for
precipitation of the sugar is again obtained.
The essential feature of the process, in addition to the novel application of the
magnesia sulphite or magnesia sulphate consists in that, by the application of
sulphurous or sulphuric acid, a closed-circuit process is obtained, in which the
barium hydroxysulphide employed for the separation of the sugar, as also the
sulphurous or sulphuric acid employed are regenerated.
Having now particularly described and ascertained the nature of this inven-
tion and in what manuer the same is to be performed 1 declare that what I
claim is :-
1. The separation, extraction or production of sugar from saccharine liquors.
such as molasses, by bariumhydroxysulphide in a circular process consisting in the
gaining of sulphuretted hydrogen from the vinasse lye containing bariumhydro-
sulphide by means of carbonic acid, for the manufacture of sulphurous or sulphuric
acid in order to decompose the obtained saccharate of barium into sugar solution.
and sulphite or sulphate of barium and to convert the carbonate of barium.
obtained from the vinasse lye into the same compounds from which, by reduction.
and lixiviation with water, barium hydroxysulphide may be gained.
2. In the circular process described in the first claim the modification that, in:
the place of carbonic acid, sulphurous or sulphuric acid for the decomposition of
the saccharate of barium, and of carbonic acid for the decomposition of the vinasse
lye containing bariumhydrosulphide, there is employed sulphite or sulphate of
magnesia, whereby in the decomposition of the vinasse lye, with liberation of
sulphuretted hydrogen which is converted into sulphurous or sulphuric acid, a
mixture of sulphite or sulphate of barium with magnesia is obtained, this being.
converted by being treated with carbonic acid into an insoluble mixture of sulphite
or sulphate of barium and carbouate of magnesia, whereupon this mixture (after-
the separation from the sugar solution or from the vinasse lye) is treated with
sulphurous or sulphuric acid, and the sulphite or sulphate of barium separated
from magnesium compounds, is converted into barium bydroxysulphide by fusion
with carbon and lixiviation of the fused mass with water, the dissolved sulphite or
sulphate of magnesia being again used for the decomposition of the saccharate or
the vinasse lye, substantially as described.
Deted this 98th dow of October 1896
ABEL & IMRAY,
Agents for the Applicant..