IMPROVEMENTS IN THE PURIFICATION OF SYRUPS and Sugar
Year: 1873

page_text: LETTERS PATENT to Alexander Melville Clark, of 58, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
“IMPROVEMENTS IN THE PURIFICATION OF SYRUPS and Sugar."-A com-
munication from abroad by Louis Joseph Frédéric Margueritte, of
Paris, France,
PROVISIONAL SPECIFICATION left by the said Alexander Melvillo
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 22nd February 1873.
I, ALEXANDER MELVILLD CLARK, of 53, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for “IMPROVEMENTS IN THE PURIFICATION OF SYRUPS AND Sugar," to
be as follows:-
This Invention relates to the purification of syrups of beetroot, cane,
maple, or other sugar, with a view to render them suitable for con-
sumption as syrups or for the preparation of fermented liquors, or when
it is desired to extract the crystallizable sugar therefrom I obtain by

page_text: the process of this Invention a much larger per-centage of sugar of a
sufficiently good quality for immediate comsumption, the inferior products
(equivalent to "bastards") being suitable for making beer and other uses.
The means employed for producing this result is the same in both
cases, viz., by the action of acids on the saccharine juices in a boiling 5
state.
First. In order to obtain syrups for direct consumption the sugar
contained in which may without much inconvenience be partially
inverted, weak acids may be employed in considerable proportions, or
strong acids in lesser proportions, the boiling being effected either in a 1
vacuum or otherwise.
Secondly. When on the other hand it is desired to carefully avoid the
inversion of the sugar in order to extract it in a crystallizable state, the
proportion of acid should be determined with great nicety with regard
to the quantity of dry material or that of the ashes (cendres) contained 1
in the saccharine juice.
The following is the improved method of purifying syrups intended
for consumption in that form or for fermentation:-I tako syrup obtained
from any kind of sugar and add according to its degree of purity a
quantity of sulphuric, hydrochloric, phosphoric, or other acid equal to 2
3, 6, or 10-thousandths of the dry matter contained in the syrup. The
liquor is then boiled either in a vacuum or otherwise to "proof"; water
is next added and the liquor again boiled with fine animal charcoal, by
the injection of steam, afterwards saturating with lime in case the juice
should still retain any acidity. The animal charcoal is then either g
decanted or separated by centrifugal force in a rotary machine with
closed sides (non-filtering), the syrup being evaporated.
It is sometimes necessary to filter the syrup before acidulating it,
where it cannot be conveniently evaporated during the first stage of
purification.
By the above treatment a syrup of excellent flavor and of a quality
suited to the various uses to which it may be applied, such as goldon
syrup, syrup for preserving, and that used in the fermentation of beer.
Among the acids which may be used phosphoric acid gives very good
results, inasmuch as it immediately eliminates the limo in an insoluble
state, so that the syrups do not ultimately become turbid as when

page_text: sulphuric acid is used, and the salts have not the saline flavor of
chlorides. When however hydrochloric acid is employed the chlorides
may be readily eliminated by dialysis or osmose, and furnish an excellent
syrup.
It is unnecessary to add that when speaking of phosphoric acid the
bi-phosphate of lime is employed in practice.
In treating saccharine juices with a view to extract crystallizable
sugar the operation is conducted in the following manner :-The juice
is first defecated and saturated by the ordinary means, and when of a
density of from 27 to 80 degrees Beaumé it is discharged from the triplo
evaporator into a vessel, where it is mixed after cooling with a certain
proportion of acid (for example 1lb of hydrochloric acid of commerce at
20 degrees Beaumé to every 100 lbs. of dry material), but preferably
sulphuric or hydrochloric acid on account of their energetic action and
low prico,
Ammonia salts in general, such as hydrochlorate or sulphate, may
also be used, but the results are not comparable with those obtained by
the use of free acids. I use hydrochloric acid for the treatment of
beetroot juice, but sulphuric acid may be used without inconvenience
in the case of cane juice. The acid is diluted in 5 or 6 times its volume
of water, and run in a small stream into the mass of syrup, which is
kept constantly stirred. Immediately the desired quantity of acid has
been added and the mixing is completed the juice is returned either
into the triple evaporator or into a special apparatus to be concentrated
as highly as possible at the lowest possiblo temperature in vacuo,
This temperature should not ordinarily exceed 120 to 180 degrees
Fahrenheit, although it may be increased without causing any great
inconvenience. Under these conditions it will be seen that a boiling in
acid is effected differing entirely from the ordinary methods,
From the quantity of acid employed it will be understood that it is
not used simply for producing a mere acid reaction of the liquor
although even this is carefully avoided by sugar makers, but as a
medium, in which after some hours boiling and complete concentration.
it might be supposed there would not remain a vestige of crystallizablo.
sugar. The proportion of acid before given may however be oven
increased without danger of producing an inversion of the sugar,

page_text: As another advantage derived from this treatment with acid the
uncrystallizable salts of molasses may be either partially or wholly
replaced by crystalloid salts, which by dialysis will furnish improved
results to those obtained hitherto with ordinary molassos.
It is evident that beetroot molasses treated and purified in the manner
herein-before described may be freed by "osmose" from the chlorides
when treated with hydrochloric acid and other salts they contain with
a considerable gain as regards flavor and value as a fermenting agent.
This Invention thus includes the preparation of "thirds" or molasses,
properly so called by "osmose," as also (although with less advantage)
the simple acidulation of the juices to be "osmosed," as in this caso
the presence of the organic acids displaced has the disadvantage of
stimulating the passage of the sugar and nullifies a portion of the
advantages resulting from the formation of chloride of potassium, which
is much more diffusible than the uncrystallizable salts of potash.
According to the process herein-before described the acid is added to
the saccharine juice at a density of 30 degrees Beaumé, and a preliminary
ovaporation is then operated, by which means the amelioration of the
1st, 2nd, and 3rd qualities and also of the molasses is obtained in onc
operation. The improvement may however be applied to "seconds'
before passing to the hydro-extractor, whereby the sugar obtained will
have a much lower saline co-efficient, be much purer, and consequently
of more value.
The following is the method of treatment:-I take the concentrated
material, consisting of "seconds" of the ordinary manufacture, and pass
it to the mixer as usual to reduce it to a semi-liquid condition. To every
hundredweight I then add about 7 lbs. (4 pints) of hydrochloric acid of
commerce, marking 20 degrees Beaumé. These proportions apply to a
concentrated material ("seconds") containing 16 per cent. of ashes
(cendres), and will vary according to the amount of the latter. It is
then returned to the apparatus in order that the mixing of the acid with
the saccharine mass may be as completo as possible. After this the
material may be passed at once to the hydro-extractor, or after a longer
or shorter interval without danger of inversion in order that the acid
may have full effect. The sugar obtained is much less colored than the
ordinary "seconds" quality, and much purer, inasmuch as it contains
less molasses and consequently a less amount of salts. The acid added

page_text: has the effect of decomposing the viscous salts in the molasses, and also
increases the fluidity of the medium so that it is more readily eliminated
by centrifugal force. The fluidity of the syrup thus acidulated is nearly
the same as that of the mother water of the first quality, so that it may
be clarified by means of water, which is very efficacious in removing the
slightest traces of the acid liquid impregnating the sugar.
If necessary a small quantity of saccharate of lime might be added
to the clearing water, which would suffice for completely neutralizing
the centrifugaled sugar. The syrup which drains from the hydro-
extractor is naturally acid, and in this condition it is concentrated, as
in the caso of the saccharino juices at 30 degrees Beaumé before
described, and a third quality syrup is thus obtained, which produces
a large quantity of sugar, inasmuch as the concentration may be carried
still further, and of greater purity owing to the contrifugal treatment
being simple and more effectual. Thus the acid may be added at any ·
period of the manufacture cither immediately after defecation to the
syrup at 30 degrees Beaumó or to the concentrated matters of 1st, 2nd,
or 3rd quality, whereby to fluidize the syrups and molasses and thus to
moro perfectly cleanse, or purify sugars. It is preferable however for
producing 1st, 2nd, and 3rd quality sugars of good flavor, and of which
perfectly limpid solutions are to be obtained to apply the acid purification
at the commencement of the manufacture, that is to say, to the saccharino
juice.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 22nd August 1878.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of February, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE PURIFICATION OF SYRUPS AND SUGAR," a communication
to me from abroad by Louis Joseph Frédéric Margueritte, of Paris, France,
upon the condition (amongst others) that I, the said Alexander Melville
Clark, executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same is
to bo performed, to be particularly described and ascertained in and by
the following statement, that is to say :—
This Invention relates to the purification or amelioration of syrups of
bectroot, cane, maple, or other sugar producing substance, with a view
either to render them suitable for consumption and for the preparation
of fermented beverages, or to extract the crystallizable sugar therefrom,
in which case I obtain by the process of this Invention a much larger

page_text: per-centage of sugar of a sufficiently good quality for immediate con-
sumption, the inferior products being equivalent to “bastards," and
suitable for making beer and for other uses. The means of obtaining
theso results is the same in both cases, viz., the action of acids on the
saccharino juices when in a boiling state.
First. In order to obtain syrups the sugar contained in which may
without much inconvenience be partially inverted, weak acids may bo
employed in considerable proportions, or strong acids in lesser pro-
portions, the boiling being effected either in a vacuum or otherwise.
Secondly. When on the other hand it is required to carefully avoid
the inversion of the sugar in order to extract it in a crystallizable state
the proportions of acid should bo determined with great nicety with
regard to the quantity of dry matter or ashes contained in the saccharine
juico.
The following is the improved method of purifying syrups intended
for direct consumption or for fermentation:-Take syrup obtained
from any source and add according to its degree of purity a quantity
of sulphuric, hydrochloric, phosphoric, or other acid equal to 3, 6, or
10-thousandth parts of the dry matter contained in the syrup. The
liquor is then boiled to proof either in a vacuum or otherwise, then
dissolved in water and boiled with fine animal charcoal by the aid of
steam, saturating with lime in case the juice should still bo acid. The
animal charcoal is separated either by decantation, by filtration in a
filter press, or by centrifugal force in a rotary machine having plain
› sides (non-filtering), and the syrup is evaporated to proof.
It is sometimes necessary to filter the syrup through charcoal before
acidulating in caso it cannot be properly evaporated at the first stage of
purification.
By the above treatment I obtain a syrup of excellent flavor and of a
quality suited to the various uses to which it may be applied (golden
syrup, preserves, and the fermentation of beer).
Among the acids which may be used phosphoric acid gives very good
results, inasmuch as it immediately eliminates the lime in an insoluble
state, so that the syrups do not ultimately become turbid as when
sulphuric acid is used, and the salts produced have not the saline flavor
of chlorides. When however hydrochloric acid is employed. tho chlorides

page_text: may be readily eliminated by dialysis or osmose and an excellent syrup
be obtained.
It is necessary to add that in speaking of phosphoric acid it is the
bi-phosphate of lime which is employed in practice.
In treating saccharine juice with a view to extract crystallizable sugar
the operation is conducted in the following manner:-The juice defecated
and saturated by the ordinary means and brought to a density of from
27 to 30 degrees Beaumé is discharged from the "triple effect apparatus"
into a trough, where it is mixed after cooling with a certain proportion
of an acid, but preferably sulphuric or hydrochloric acid on account of 1
their energetic action and low price.
Ammonia salts in general, such as the hydrochlorate or sulphate, may
also be used, but the results are not comparable with those obtained by
the use of free acids. I use bydrochloric acid for the treatment of
beetroot juico, but sulphuric acid may be used without inconvenience ]
in the case of cane juice. The acid is diluted with 5 or 6 times its
volume of water, and runs in a small stream into the mass of syrup,
which is kept constantly stirred. Immediately the desired quantity of
acid has been added and the mixing is completed the juice is returned
either into the third pan of the triple effect or into a special apparatus 2
to be concentrated as highly as possible at the lowest possible temperature
in vacuo. This temperature should not ordinarily exceed 120 to 130°
Fahrenheit, although it may be exceeded without causing any serious
inconvenience. Under these conditions it will be seen that a very acid
treatment is effected, differing entirely from and exactly the reverse of 2
the ordinary methods and accepted theorics.
From the quantity of acid employed it will be understood that it is
not used simply for producing a merc acid reaction of the liquor
(although even this is carefully avoided by sugar makers), but as a
medium in which after some hours boiling and complete concentration 3
it might be supposed there would not remain a vestige of crystallizable
sugar.
The following are the proportions of acid which have been employed
in the treatment of the juices according to this Invention:-To 220 lbs.
of dry matter, as indicated by Balling's hydrometer obtained from the 3
first quality syrup, is added 1·10 lbs. of So³ IIo or ½ per cent., or 13 oz.
of Hel, or 1.750 pint, or 2-2 lbs. of hydrochloric acid of commerce of a

page_text: density of 1.16 corresponding to 20 degrees Beaumé. Or by calculating
according to the quantity of ashes contained in the dry matter an
addition of hydrochloric acid of commerce should be made equal to
21.6 per cent. of the weight of said ashes. For example with the first
quality, which would contain 13-2 lbs. of ash, 2.2 lbs. of hydrochloric
acid of commerce, would be employed, marking 20 degrees Beaumé.
These Figures, with regard to the volume, represent at a minimum
42-7 cubic inches of hydrochloric acid for every 22 gallons of syrup at
30 degrees Beaumé.
The above proportions of acid are however not essential, and may
even be increased without danger of inversion, although they serve to
show that the acid is added to the juice in very large quantities, which
is altogether beyond anything hitherto attempted. There is no danger
of the inversion of the sugar, inasmuch as the powerful acids employed
are on contact with the salts contained in the syrups immediately
saturated by the bases of the organic salts which they decompose, and
are replaced by the weak acids which they displace. These weak acids
have no sensible action on the sugar when boiled in vacuo, that is to
say, at a temperature not exceeding 130 to 140 degrees Fahrenheit.
Morcover they are volatilo to a great degree, and pass off from tho
liquor, so that the loss of sugar in manufacture is only from 0·21, 0·30,
or 0·10 per cent., and generally below the latter Figure. The boiling
however, which extends over several hours, is effected in the presence of
considerable quantities of weak acid, the proportion of which is exactly
equivalent to that of the hydrochloric acid employed. During tho
boiling they are carried off under the influence of the vacuum, with tho
water of condensation, and almost entirely disappear. When the con-
centrated syrup or "masso cuito" is redissolved in water for the purpose
of being filtered before being definitely boiled to grain, the presence of
acid in the liquor will scarcely be perceptible when tested with litmus
paper, and this slight acidity will entirely disappear on contact with
animal charcoal, the juice on leaving the filter having rather an alkaline
reaction.
The following are the essential conditions of success in purifying
saccharino juices according to this improved method:-1st, the pro-
portion of the acid to be employed must be determined with exactness,
which may be done in a very simple and speedy manner; 2ndly, as
perfect a vacuum as possiblo must be obtained in the apparatus with a

page_text: consequent low temperature; 3rdly, care must be taken in practise to
keep well below the quantity of acid theoretically necessary to decompose
all the organic salts, it being useless to approach too nearly the limit
beyond which inversion would be produced.
The advantages are the following:-1st, improved odour and flavor
of the mass treated and of the sugar obtained; 2ndly, a considerable
reduction of the saline co-efficient in the second produce or quality,
whereby the sugar is raised in value from 10 to 12 shillings per bag;
3rdly, an increased product of the first and second qualities amounting
to not less than 2 per cent. each; 4thly, facility of evaporating and
concentrating syrups, which have become too fluid during their purifi-
cation owing to the modification of the extractive pectic matters and
the transformation of the deliquescent uncrystallizable salts into
chlorides, of which the most highly concentrated solution is neither
thick nor syrupy.
It has been before stated that hydrochloric acid is used in preference
to sulphuric, phosphoric, or other acids, the salts contained in the syrup
being therefore transformed into chlorides, and it would be naturally
inferred that sea salt would be formed, which is very injurious, but it must
be remarked that it is the stronger base which will unite with the hydro-
chloric acid, that is to say, the potash which constitutes the greater part of
the saline properties of beetroot, and which is thus in more than sufficient
proportion to saturate the relatively small quantity of acid added. Thus
it is not chloride of sodium which is formed (an extremely melassigenous
salt), but chloride of potassium, which does not combine with the sugar
to any great extent, as is the case with the uncrystallizable salts and
gums, nor retard its crystallization, inasmuch as it will also crystallize
with it while it is sufficiently soluble to remain in solution even in the
last products obtained.
Although the chloride of potassium will not prevent the crystallization a
of the sugar it is also probable that it does not assist it, but there can

page_text: possibility of more highly concentrating the mass, and so bringing it to
a higher degree of crystallization.
The augmentation in the value of the second produce or quality by
reducing the proportion of the salts is consequent on the more efficient
centrifugaling, inasmuch as the syrup is more fluid and adheres less to
the sugar crystals.
As another advantage derived from this treatment with acid the
uncrystallizable salts of the molasses may be either partially or wholly
replaced by crystalloid salts, and which by osmoso or dialysis will
furnish better results than those obtained hitherto with ordinary
molasses.
It is evident that beetroot molasses treated and purified in the manner
horein-before described may be freed by osmosmic action from tho
chlorides (when treated with hydrochloric acid) and other salts they
5 contain with a considerable gain as regards flavor and value as a
fermenting agent.
This Invention thus includes the preparation of thirds or molasses,
properly so called by osmosmic action or diffusion, as also (although
with less advantage) the simple acidulation of the juices to be submitted
0 to osmosmic action, as in this caso the presence of the organic acids
displaced has the disadvantage of stimulating the passage of the sugar
and nullifies a portion of the advantages resulting from the formation
of the chloride of potassium, which is much more diffusible than the
uncrystallizable salts of potash.
5. From the foregoing description it has been shown that by the action
of acids, 1st, the flavor and odour of syrups and saccharine matters are
ameliorated; 2ndly, the per-centage of crystallized sugar is increased;
3rdly, the quantity of salts retained by the second and third products is
diminished, while the commercial value of the lower qualities is increased
30 by lowering the saline co-efficient; 4thly, the syrups and molasses aro
rendered more fluid and thus casier to climinate by the centrifugal
machine.
According to the process herein-before described the acid is added to
the saccharine juice at a density of 30 degrees Beaumé, and a preliminary
35 evaporation is operated, by which means the amelioration of the 1st,

page_text: 2nd, and 3rd qualities, and also of the molasses is effected at one
operation. The process may however be applied to the second quality
or produce before being centrifugaled, whereby the sugar obtained will
have a much lower saline co-efficient, be much purer, and consequently
of more value.
The following is the method of treatment:-The second quality of
the ordinary manufacture is passed to the mixer as usual to reduce it to
a liquid pasty condition. To every 220 lbs. I then add 6-8 lbs. (4-7 pints)
of hydrochloric acid of commerce, marking 20 degrees Beaumé. These
proportions apply to a second quality containing 16 per cent. of ashes,
and will vary according to the amount of the latter. It is then returned
to the apparatus in order that the mixing of the acid with the saccharine
mass may be as complete as possible. After this it may be centrifugaled,
either at once or after a longer or shorter interval, without danger of
inversion to allow the acid to have its full effect. The sugar obtained 1
is much less colored than the ordinary second quality and much purer,
inasmuch as it contains less molasses and consequently a less amount of
salts. The acid added has the effect of decomposing the viscous salts in
the molasses, and also increases the fluidity of the medium, so that it is
more readily eliminated by centrifugal action. The fluidity of the syrup 2
thus acidulated is nearly the same as that of the mother water of the
first quality, so that a clarification by means of water may be effected,
which is very efficacious in removing the slightest traces of the acid
liquid impregnating the sugar.
If necessary a small quantity of saccharate of lime might be added to 2
the water, which would suffice to completely neutralize the centrifugaled
sugar. The syrup which drains from the hydro-extractor is naturally
acid, and in this condition it is concentrated, as in the case of the
saccharine juices at 30 degrees Beaumé before described, and a third
quality syrup is thus obtained, which produces a larger quantity of sugar 30
because the concentration may be carried further, and which sugar is of
greater purity owing to the centrifugal treatment being more effectual.
Thus it will be seen that the acid may be added at any period of the
manufacture, either immediately after defecation to the syrup at
30 degrees Beaumé, or to the concentrated syrups of 1st, 2nd, or 35
3rd quality, and that the syrups and molasses may be fluidized, and a
more perfect cleansing and purification of the sugars bo thereby obtained.
It is preferable however for producing 1st, 2nd, and 3rd quality sugars

page_text: of good flavor, the solutions of which are to be perfectly limpid, to effect
the purification by means of acid, once for all, at the commence-
ment of the manufacture, that is to say, by treating the saccharine juice.
It will be evident that by adding hydrochloric or other acid to the
molasses an acid clarifying agent may be prepared for purifying other
inferior quality sugars purchased for the purpose.
The acid clarifying agent, or in a word molasses, employed for the
above purpose is ovaporated in vacuo and converted into molasses of
good flavor, and will serve for an indefinito number of times by the
simple addition of fresh acid.
It is unnecessary to add that the quantity of acid used will be pro-
portionate to the salts, that is to say, to the molasses contained in the
sugar to be purified.
Having described the nature of the Invention, and the manner in
which the same is to be performed, I declaro that what I claim as the
Invention to bo protected by the herein-beforo in part recited Letters
Patent is,-
1st. The addition of an acid (more especially an energetic acid, such
as sulphuric or hydrochloric acid) in the proportions indicated to the
juice, whether diluted or concentrated. The boiling of the acidulated
liquor either in vacuo or otherwise at a temperature of from 120 to
140 degrees Fahrenheit. The boiling of the syrup, which is redissolved
in water, filtered through animal charcoal, and finally evaporated for tho
purpose either of granulating it or of forming glucose syrup, all as
; herein described.
2ndly. I claim the evaporation cither in vacuo or otherwise for
improving molasses and preparing golden and glucose syrups, and also
the evaporation in vacuo when extracting crystallizable sugar to avoid
inversion and the loss of considerable quantities of sugar, all as herein.
) beforo described.
3rdly. I claim the addition in a cold state to the concentrated mass
after granulation (which may be either of first, second, or third quality)
of a quantity of acid proportionate to the amount of ashes contained,
and then mixing and centrifugaling the same, as herein described.

page_text: 4thly. I claim the preparation of an acid clarifying liquor from
molasses or other syrup for purifying sugars already centrifugaled, as
herein-before described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Twentieth day of August, 5
in the year of our Lord One thousand eight hundred and seventy-
three.