s, Syr, and Molasses.
Year: 1885

page_text: Saccharine Juices, Syrups, and Molasses.
I, LOUIS LEFRANC, of Tracy-le-Val, in the Republic of France, Sugar Manu-
facturer do hereby declare the nature of said invention for "Å METHOD OR PROCESS
FOR THE EXTRACTION OF SUGAR FROM SACCHARINE JUICES, SYRUPS, AND MOLASSES
to be as follows:-
"
This invention relates to a method or process for the extraction of sugar from
saccharine juices, syrups and molasses.
It is well known that when lime is dissolved in a saccharine solution until the
sugar contained in the latter is saturated therewith a soluble sucrate of lime is
formed. When this solution of sucrate of lime is subjected to the action of heat,
a nearly insoluble precipitate of another sucrate is formed corresponding to the
formula of the tribasic sucrate (C" H" 0" 3 Ca O). The formula for this reaction
appears to be as follows: 3 (C" Hи O¹¹ 2 Ca 0) = 2 (C¹³ H¹¹ 0 3 Ca O) + C¹³
HO. With the aid of heat this sucrate can be separated by filtration from its
mother liquor and sugar may be extracted therefrom by causing the lime contained
therein to be rendered insoluble or it can be utilized in the refining of saccharine
juices and syrups. The defects attending this process are clearly shown by the
preceding formula.
The conversion of sugar into tribasic sucrate is never complete. It is therefore
necessary either to recommence several times the preceding operations upon the
liquor which becomes gradually exhausted, or to have recourse to the process of
substitution.
Whatever may be the value of these two alternatives, it results clearly from the
above formula that this process for the extraction of sugar only produces good
results when the yield of the liquor in sugar is somewhat considerable that is to
say from 5 to 12 per cent.
It is also known that the following process has been employed for extracting
sugar from saccharine juices, syrups and molasses obtained from sugar manu-.
facturies. This process consists first in dissolving lime in a saccharine solution
until the sugar contained therein is saturated, corresponding to the formation of
a bibasic sucrate then adding to a solution of the latter a certain quantity of a
salt of lime in solution, corresponding to the quantity of lime required in order to
produce an insoluble sucrate and finally in adding an alkaline base to the mixture.
IE671

page_text: By means of this process a precipitate of tribasic sucrate of lime is obtained,
without the aid of heat by virtue of the following reaction.
=
3 (C¹ HO¹¹ 2 Ca O) + Ca Cl + Na O 3 (CHO 3 Ca O) + Na Cl
applicable in the case for instance when chloride of calcium and soda are used.
This process, which appears from the above theoretical formula, to be perfect,
in so far that all the sugar is completely converted into an insoluble sucrate has not
received any useful application commercially on account of the somewhat high
price of soda, and, especially, because the presence in too large a quantity of this
reagent renders the filtration impossible. This process therefore can only be
applied when the saccharine liquors under treatment have but a feeble yield in
Bugar.
It results from the above that the first process only gives good results when the
liquors have a somewhat considerable yield in sugar, while the second on the
contrary can only be carried into practice commercially when the yield in sugar is
small.
According to this invention the two methods above described are combined and
modified in order to realize their advantages and remedy their defects my invention
thus forming a new process for the treatment of molasses. This process comprises
two distinct operations.
The first consists in forming an insoluble sucrate. The second consists in treating!
the mother liquor of the said sucrate in such a manner as to be able to extract
sugar therefrom.
1T OPERATION. FORMATION OF AN INSOLUBLE SUCRATE.
The molasses or the drainings of 1st, 2nd or 3rd jets &c containing from 5 to
10 per cent of sugar are conducted into a mixer, and cold milk of lime containing
50 to 80 parts in weight of lime per hundred parts in weight of sugar contained
in the solution, is added.
This quantity of lime would be insufficient for producing a complete reaction but
it has the advantage of commencing it without any sudden rise of temperature,
an essential condition for a large formation of bibasic sucrate which is the only 3
one, as is well known, which can be split up the most completely by heat into
tribasic sucrate and sugar.
When the mixture is quite homogeneous and when the reaction is finished, I add
quick lime reduced into as impalpable a powder as possible and I continue the
mixing operation until the sugar is thoroughly saturated with lime. The quick 3
lime added represents 50 to 70 per cent of the weight of the sugar; this lime
must be added little by little in order to avoid a rise in the temperature of the
mixture which might still occur. The saturation of the sugar being obtained,
I filter, by means of pockets or filtering presses, the calcic sucrate in order to
separate it from the excess of lime contained therein and I conduct it into a 4
reheating boiler to be subjected to the action of heat.
As the temperature gratually rises towards 50 degrees centigrade, the liquor
becomes cloudy in consequence of the formation of tribasic sucrate which formation
is completely effected when the boiling point is reached according to the formula.
3 (C¹ H¹¹¹¹ 2 Ca O) = 2 (C¹² "Q" 3 Ca O) + C¹³ H¹ O¹¹.
This point reached, the excess of lime which had been omitted in order to
facilitate the conversion of the soluble sucrate into an insoluble sucrate is gradually
added to the liquor which is maintained constantly at the boiling point.
The re-addition, in the operation of this excess of lime has two important
advantages; it obviates the losses in sugar which it would unavoidably entail 5
and renders the sucrate more suitable for washing, by giving it, owing to the
presence of an excess of lime, more porosity and accordingly more permeability.
It is known that tribasic sucrate of lime is a gelatinous substance and, con-
sequently, difficult to filter. The presence of an excess of lime obviates this serious

page_text: annicuity. Thus, according to my system, fime is removed when its presence is
injurious and on the contrary it is reintroduced into the liquor when its presence
has become necessary. After the mixture has been effected I separate the insoluble
sucrate from its mother liquor by conveying it at the above named temperature to
the filtering and washing presses, either by means of pumps or by means of a syrup
elevator. The sucrate remains in the apparatus in the form of cakes which are
washed with boiling water, and the mother liquor that runs out is subjected to the
second operation.
The sucrate thus formed is collected and transferred to a mixer; it is then
converted into an emulsion or thin paste suitably diluted either for liming juices or
syrups or for recovering the sugar therefrom by eliminating the lime in an insoluble
anicuity. inus, according to my system, fime is removed when its presence is
injurious and on the contrary it is reintroduced into the liquor when its presence
has become necessary. After the mixture has been effected I separate the insoluble
sucrate from its mother liquor by conveying it at the above named temperature to
the filtering and washing presses, either by means of pumps or by means of a syrup
elevator. The sucrate remains in the apparatus in the form of cakes which are
washed with boiling water, and the mother liquor that runs out is subjected to the
second operation.
The sucrate thus formed is collected and transferred to a mixer; it is then
converted into an emulsion or thin paste suitably diluted either for liming juices or
syrups or for recovering the sugar therefrom by eliminating the lime in an insoluble
State.
2ND OPERATION. TREATMENT OF THE MOTHER LIQUOR.
The mother liquor collected in the preceding operation containing only about
3 per cent of sugar cannot be successfully treated by the above process unless they
were restored to their original strength in sugar, by adding thereto a fresh quantity
of molasses; I have however found defects in such a method which have caused
me to abandon it.
I prefer to use the following process―
The mother liquor is transferred upon issuing from the filter press to a suitable
refrigerator in order to be brought down to the normal temperature or it is
directly conveyed, when circumstances permit to a vat, where it is allowed to cool.
When the mother liquor is cooled, I add thereto an excess of quick lime in order
to fully saturate the sugar contained therein with lime in order to form as in the
preceding case a soluble sucrate. The addition of the quick lime may even take
place before cooling provided that before the succeeding operation, the temperature
most favorable for the formation of this soluble sucrate has been reached.
As in the first of the operations, this mother liquor is freed for the same reason
from the excess of lime; then it is conveyed into a reheating boiler which may be
usefully provided with a mixer.
It is to be remarked here that in consequence of the small proportion of sugar,
the addition of quick line even in excess does not cause the temperature to rise
sufficiently to promote the formation of monobasic sucrate; I therefore obtain
bibasic sucrate almost exclusively. But as by the action of heat this bibasic
sucrate is decomposed into tribasic sucrate and sugar which is lost or would
necessitate a subsequent operation, I add in the boiler a solution of chloride of
calcium in sufficient quantity to form an insoluble sucrate of lime. I mix
intimately, heat, then I add a quantity of caustic soda in equivalent proportion
to that of the chloride of calcium which has to be decomposed. As soon as
this addition is effected either with or without the aid of heat the reaction
takes place.
By the action of heat the bibasic sucrate of lime is decomposed as is well known
into tribasic sucrate and into sugar; but on the other side, the lime, released by
the substitution of the sodium of the soda for the calcium of the chloride of
calcium, is in a nascent state which facilitates its combination with the sugar
already set free and all the sugar is finally obtained in the form of tribasic
sucrate. This re-action can be effected, owing to the presence of soda without the
aid of heat.
As above stated the operation can be effected without the aid of heat but it is
preferable to employ.heat which promotes the preceding combination and especially
facilitates the subsequent filtration.
When the temperature suitable for the separation of the sucrate is reached, the
liquid is conveyed to the filter-presses in which cakes are formed, washed and
collected in order to be used as above stated in the same manner as those pro-
ceeding from the first operation. The excess of lime which has been previously

page_text: removed can be added to that of the first operation or returned if desired to the
mother liquor after the sucrate has been precipitated therefrom. The mother
liquor can then be treated in order to extract the saline and nitrogenous organic
matters or can be utilized directly as manure.
It will be readily understood that in the 2nd above described operation I may
substitute for the chloride of calcium used, any suitable calcium salt in the same
manner as I may substitute for soda any suitable alkaline or earthly alkaline
base without departing from the principle upon which my invention is founded.
Lastly although the two preceding operations are sufficient to completely exhaust
the preceding sacharine liquors, I may however renew these operations when
required.

page_text: Saccharine Juices, Syrups, and Molasses.
I, LOUIS LEFRANC of Tracy-le-Val in the Republic of France, Sugar Manu-
facturer, 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 a method or process for the extraction of sugar from
saccharine juices, syrups and molasses.
It is well known that when lime is dissolved in a saccharine solution until the
sugar contained in the latter is saturated therewith a soluble sucrate of lime is
formed. When this solution of sucrate of lime is subjected to the action of heat,
a nearly insoluble precipitate of another sucrate is formed corresponding to the
formula of the tribasic sucrate (C¹¹¹ O¹¹, 3 Ca O). The formula for this reaction
appears to be as follows:-
3 (C¹ H¹¹ 0", 2 Ca O) = 2 (C¹³ H¹¹ 0ч, 3 Ca O) + C¹² HO¹.
With the aid of heat this sucrate can be separated by filtration from its mother
liquor and sugar may be extracted therefrom by causing the lime contained therein
to be rendered insoluble or it can be utilized in the refining of saccharine juices
and syrups.
The defects attending this process are clearly shown by the preceding formula.
The conversion of sugar into tribasic sucrate is never complete. It is therefore
necessary either to re-commence several times the preceding operations upon the
liquid which becomes gradually exhausted, or to have recourse to the process of
substitution.
Whatever may be the value of these two alternatives, it results clearly from the
above formula that this process for the extraction of sugar only produces good
results when the yield of the liquor in sugar is somewhat considerable, that is to
say from 5 to 12 per cent.
It is also known that the following process has been employed for extracting
sugar from saccharine juices, syrups and molasses obtained from sugar manu-
factories. This process consists first in dissolving lime in a saccharine solution
until the sugar contained therein is saturated corresponding to the formation of a
bibasic sucrate, then adding to a solution of the latter a certain quantity of a salt
of lime in solution corresponding to the quantity of lime required in order to
produce an insoluble sucrate and finally in adding an alkaline base to the mixture.
By means of this process a precipitate of tribasic sucrate of lime is obtained,
without the aid of heat by virtue of the following reaction :-
•
3 (C¹³ HO¹¹, 2 Ca O) + Ca Cl + Na O = 3 (C" H" 0", 3 Ca O) + Na Cl,
applicable in the case, for instance, when chloride of calcium and soda are used.
This process, which appears from the above theoretical formula, to be perfect, in
Bo far that all the sugar is completely converted into an insoluble sucrate has not
received any useful application commercially on account of the somewhat high.

page_text: in sugar.
рассца! ЩО
ипает treatment have but & recore yieru
It results from the above that the first process only gives good results when the
liquors have a somewhat considerable yield in sugar, while the second on the
contrary can only be carried into practice commercially when the yield in sugar is
small. According to this invention the two methods above described are combined
and modified in order to realise their advantages and remedy their defects, my
invention thus forming a new process for the treatment of molasses.
This process comprises two distinct operations:-The first consists in forming an
insoluble sucrate. The second consists in treating the mother liquors of the said
sucrate in such a manner as to be able to extract sugar therefrom.
1ST OPERATION. FORMATION OF AN INSOLUBLE SUCRATE
The molasses or the drainings of 1st 2nd or 3rd jets et cetera containing from 5
to 10 per cent of sugar are conducted into a mixer and cold milk of lime containing
50 to 80 parts in weight of lime per hundred parts in weight of sugar contained in
the solution is added.
This quantity of lime would be insufficient for producing a complete re-action
but it has the advantage of commencing it without any sudden rise of temperature,
an essential condition for a large formation of bibasic sucrate which is the only
one, as is well known, which can be split up the most completely by heat into
tribasic sucrate and sugar.
When the mixture is quite homogeneous and when the re-action is finished,
I add quick lime reduced into as impalpable a powder as possible and I continue
the mixing operation until the sugar is thoroughly saturated with lime. The
quick lime added represents 50 to 70 per cent of the weight of the sugar; this lime
must be added little by little in order to avoid a rise in the temperature of the
mixture which might still occur. The saturation of the sugar being obtained,
I filter, by means of pockets or filtering presses, the calcic sucrate in order to
separate it from the excess of lime contained therein and I conduct it into a
re-heating boiler to be subjected to the action of heat.
As the temperature gradually rises towards 50 degrees centigrade, the liquor
becomes cloudy in consequence of the formation of a tribasic sucrate which forma-
tion is completely effected when the boiling point is reached according to the
formula:
3 (C¹² H¹¹0¹¹, 2 Ca O): =
2 (C** H1 Q*, 3 Ca () + C1: Hồ Q".
This point reached, the excess of lime which had been eliminated in order to
facilitate the conversion of the soluble sucrate into an insoluble sucrate is gradually
added to the liquor which is maintained constantly at the boiling point.
The re-addition, in the operation, of this excess of lime has two important
advantages: it obviates the losses of sugar which would otherwise unavoidably
entail and renders the sucrate more suitable for washing, by giving it, owing to the
presence of an excess of lime, more porosity and accordingly more permeability.
It is known that tribasic sucrate of lime is a gelatinous substance and, conse-
quently, difficult to filter. The presence of an excess of lime obviates this serious
difficulty. Thus, according to my system, lime is removed when its presence is
injurious and on the contrary it is re-introduced into the liquor when its presence
has become necessary. After the mixture has been effected I separate the insoluble
sucrate from its mother liquor by conveying it at the above-named temperature
to the filtering and washing presses, either by means of pumps or by means of a
syrup elevator. The sucrate remains in the apparatus in the form of cakes which
are washed with boiling water, and the mother liquor that runs out is subjected
to the second operation. The sucrate thus formed is collected and transferred to a

page_text: mixer; it is then converted into an emulsion or thin paste suitably diluted either
for liming juices or syrups or for recovering the sugar therefrom by eliminating the
lime in an insoluble state.
2ND OPERATION. TREATMENT OF THE MOTHER LIQUOR.
The mother liquors collected in the preceding operation containing only about
3 per cent of sugar cannot be successfully treated by the above process unless they
were restored to their original strength in sugar, by adding thereto a fresh quantity
of molasses; I have however found defects in such a method which have caused me
to abandon it.
I prefer to use the following process:
The mother liquor is transferred upon issuing from the filter press to a suitable
refrigerator in order to be brought down to the normal temperature or it is directly
conveyed, when circumstances permit, to a vat where it is allowed to cool. When
the mother liquor is cooled, I add thereto an excess of quick lime in order to fully
saturate the sugar contained therein with lime in order to form as in the preceding
case a soluble sucrate. The addition of quick lime may even take place before
cooling provided that before the succeeding operation, the temperature most
favorable for the formation of this soluble sucrate has been reached.
As in the first operation, this mother liquor is freed by filtration, and for the
same reason, from the excess of lime; then it is conveyed into a reheating boiler
which may be usefully provided with a mixer.
It is to be remarked here that in consequence of the small proportion of sugar,
the addition of quick lime even in excess does not cause the temperature to rise
sufficiently to promote the formation of monobasic sucrate; I therefore obtain
bibasic sucrate almost exclusively. But as by the action of heat this bibasic
sucrate is decomposed into tribasic sucrate and sugar which would be lost or
necessitate a subsequent operation, I add in the boiler a solution of chloride of
calcium in sufficient quantity to form an insoluble sucrate of lime. I mix
intimately, heat, then I add a quantity of caustic soda in equivalent proportion to
that of the chloride of calcium which has to be decomposed. As soon as this
addition is effected either with or without the aid of heat the reaction takes
place.
By the action of heat the bibasic sucrate of lime is decomposed as is well known
into tribasic sucrate and into sugar; but on the other side, the lime, released by the
substitution of the sodium of the soda for the calcium of the chloride of calcium, is
in a nascent state which facilitates its combination with the sugar already set free
and all the sugar is finally obtained in the form of tribasic sucrate. This re-action
can be effected, owing to the presence of soda, without the aid of heat.
As above stated the operation can be effected without the aid of heat but it is
preferable to employ heat which promotes the preceding combination and especially
facilitates the subsequent filtration.
When the temperature suitable for the separation of the sucrate is reached, the
liquid is conveyed to the filter-presses in which cakes are formed which are
washed and collected in order to be used as above stated in the same manner as
those proceeding from the first operation.
The excess of lime which has been previously removed can be added to that of
the first operation or returned if desired to the mother liquor after the sucrate has
been precipitated therefrom. The mother liquor can then be treated in order to
extract the saline and nitrogenous organic matters or can be utilized directly as
manure.
It will be readily understood that in the 2nd above described operation I may
substitute for the chloride of calcium used, any suitable calcium salt in the same
macner as I may substitute for soda any suitable alkaline or earthy alkaline base
without departing from the principle upon which my invention is founded.

page_text: Lastly, although the two preceding operations are sufficient to completely
exhaust the preceding saccharine liquors, I may however renew these operations
when required.
• Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The above described process for the extraction of sugar from juices, syrups,
and molasses from sugar manufactories and refineries, comprising the combination
of the following successive operations ;-(a) Treatment of a saccharine solution by
milk of lime and pulverized quick lime in order to form a soluble sucrate of lime;
filtration to separate the excess of lime; beating to about 100° C; re-introduction
of the previously filtered lime; further filtration; washing and subsequent treat-
ment of the tribasic sucrate of lime formed; (b) Treatment of the mother liquor
resulting, from the preceding operations with quick lime; filtration in order to
separate the excess of lime; addition to the liquid of a salt of lime preferably
chloride of calcium in sufficient quantity to form tribasic sucrate of lime; addition
of an alkaline or earthy alkaline. base, preferably caustic soda; filtration; washing
and subsequent treatment of the tribasic sucrate of lime formed.
2. The treatment of saccharine solution first with milk of lime and subsequently
with quick lime in order to obviate heating of the solution such as would interfere
with the formation of the bibasic sucrate of lime.
3. The reintroduction of the lime into the saccharine solution, when, under the
influence of heat the bibasic sucrate has been converted into tribasic sucrate, in
order to prevent losses in augar and facilitate filtration.