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Jan. 7, 1947.
2,413,791
R. w. SHAFOR
FRACTIONATION 0F SOLUTES
Filed May 9, 1942
I'OYAQ L
2 Sheets-Sheet l
NC
“I
X
Ii
INVENTOR
RALPH W. SHAFOR
BY
’
‘I
mmdkm
ATTORNEY
Jan. 7, 1947.
2,413,791
R. w. SHAFOR
FI‘RACTIONATION OF SOLUTES
Filed May 9, 1942
2 Sheet>-Sheet 2
IN'VENTOR
RALPH W. SHAFOR
BY
ATTORNEY
2,413,791
Patented Jan. 7, 1947
UNITED STATES PATENT. OFFICE
2,413,191‘
'
FRACTIONATION, 0F SOLUTES
Ralph W. Shai'or, New York, N. Y" assignor to
The Don‘ Company, a corporation or Dela»
,
ware
Application May 9, 1942, Serial No. 442,385
5 Claims. (GE. 23-1)
3
portion of the effluent solution ?owing from the
This invention relates to the puri?cation of»
sugar-bearing solutions or sugar juices by treat
bed;
ment with ion exchange materials whereby the
solution is subjected sequentially to treatment in
sent an improvement upon or_ a re?nement over
a cation and an anion exchanger bed, and more
speci?cally this relates to a method of operation
coupled with such ion exchange treatment,
whereby certain non-sugar solutes in the juice
'
The present invention may be said to repre
the substance of the‘ Rawlings invention above
outlined, such re?nement residing in the use of
spent 'regenerant solution as an auxiliary solu
tion for displacing the organic constituents from
the bed in a manner to be hereinafter further ex
can be isolated and recovered.
This invention is based on the discovery that 10 plained.
An ionic exchanger is usually represented in
ion exchange material for example the synthetic '
the form of a unit or cell containing a bed of the
resinous kind, will selectively take up from the
exchanger material proper which is usually gran
sugar-bearing solution certain non-sugar con
. ular. An exchanger has the ability to absorb
stituents in accordance with certain affinities ex
isting between respective constituents and the 15 from the solution an ion of an ionized solute and
to give off into the solution in exchange an ion
exchange material. More speci?cally with re
of another kind even though of like electric
spect to a?inities such exchange material dis
charge. Therefore, cation exchangers as‘ a class
criminates ‘between inorganic non-sugar ions and
exchange positively charged ions, whereas anion
organic non-sugar constituents, as has been set
forth in the co-pending patent application of 20 exchangers as a class exchange negatively
Rawlings Ser. No. 479,093.
'
‘charged ions.
.
As the solution is passed through and contacted
with the ion exchanger bed, the direct exchange
and recovery of organic non-sugar constituents
of respective ions between the solution and they
and more particularly of nitrogenous constitu
ents, asmore speci?cally exempli?ed by betaine, 25 exchanger continues until the exchanger is satu
The Rawlings invention proposes the isolation
from the solution. The isolation and eventual
recovery is effected by utilizing the preference of
the exchange material for the inorganic ions over
the organic constituents. Accordingly there re
rated with absorbed ions and its exchange ca
pacity thus exhausted. The exchange capacity
can then be restored by treatment of the ex
changer with a suitable regenerant solution.
sults a stratification or zoning in the exhausted 30 The saturation on the one hand, and the regen
eration on the other hand, represent the main
exchanger bed of respective heterogeneous non
phases of the operating cycle of an exchanger,
sugar constituents, that is inorganic as against
' whereby the exchanger may be used over and over
the organic constituents. The Rawlings inven
again.- The chemical reactions involved in the
tion proposes to pass, for instance, sugar juice
through an ion exchange bed until the in?uent 35 operating cycle are reversible equilibrium reac
tions.
end portion thereof has__become saturated with
The treatment method for attaining the fore
inorganic ions and the e?iuent end portion with
organic constituents, and to discontinue the pas
sage of the solution thus being treated before any
going objects involves broadly the passing
through an active ion exchanger bed of a solu
appreciable portion of the organic constituents is 40 tion having ionized matter desired to be isolated
therefrom for collecting in that bed the ions‘ of
displaced from the eiliuent zone. That is a con
such material, then removing such ions from the
tinued ?ow of the solution through the exchanger
exchanger bed in the form of a salt or a mixture
.bed would cause a corresponding growth in depth
of salts.
‘
of the zone of inorganic ions in the bed, at the
The objects proper of this invention are at
expense of the zone containing the organic con 45
tained by treating a solution containing a mix
stituents in the e?iuent portion of the bed. With
ture of solutes with ionic exchangers and utiliz
the bed thus retaining substantially a relative
ing in a special manner certain selective or pref
maximum of the desired organic compounds from
erential exchange characteristics thereof, in or
the solution, the organic constituents are then
displaced from the bed by means of another so 50 der to e?ect the desired isolation or fractionation
of certain ionic constituents of the solutes in the
lution containing ions having greater a?nity to
form of ‘salts or otherwise.
the exchange material than is possessed by the
Such a fractionation problem occurs for in
organic constituents, with the result that these
stance in connection with the puri?cation treat—
displaced constituents can be intercepted in rela
tively high concentration in the corresponding 55 ment of sugar bearing solutions, or sugar juices .
2,418,791,
4
3
such as obtained from beet or cane, when it is de
sirable to isolate, for instance, such values as po
tassium, aconitic acid, betaine and others' from
the bulk of impurities dissolved in the juice, and
constituent may move up or downin the order
of a?‘inities with respect to the exchanger. Thus
the order or af?nity of two constituents with re
which may also include Ca, Mg, Na and others.
The invention is therefore herein illustrated by‘
referring to the ionic exchange treatment of
sugar juice, and such exempli?cation is herein
not to be taken in any limiting sense.
change of their relative concentrations.
The apparent growth of the various strata is,
spect to an exchanger may be reversed by a
in reality, a ‘sequence or chain of successive ionic
displacement actions, inasmuch as the growing
- top stratum displaces a portion of the subsequent
Ionic exchange materials have inherent. tothem 1
a natural order of exchange a?inity with respect
to various ionic substances contained in the solu
tion. For instance, they have a preferential ac
tion for the alkaline earths, such as Ca and Mg
over the alkali metals such as represented by
K and Na, all of which may be contained in vary
ing degrees as so-called impurities in sugar juices.
Hence, from sugar juices the alkali metals with
potassium as a value may be recovered separate
from the alkaline earths. Acom'tic acid and be
taine may also be recovered from sugar juice.
More generally speaking, and in view of what
stratum of ions of another constituent, which in
turn passes the displacement on to the next
stratum that is inferior with regard to its af?nity
to the exchanger, and ‘so on down to the bottom
stratum of the bed. In this way, as the respec
tive strata or bands of the various ionic constitu
ents widen, they also appear to be shifting down
wardly through the bed until even the bottom
stratum of the bed will have been saturated with
the constituent of lowest a?lnity, at which time
the basic exchange capacity of the exchanger will
be considered as exhausted.
-
Just as there manifests itself a scale or order
of a?inity between various ions and the exchanger
during the saturation phase, so does the ex
characteristics, the progress of exhaustion of the
bed can perhaps best be visualized,‘ as follows:
25 changer conversely exhibit a correspondingse
lective reluctance or discrimination in releasing
The exhaustion or saturation of a fresh ex
di?erent ions under the pressure of ions of greater
changer bed with the solution ?OWiIlg downward
has just been said with respect to the preferential
ly therethrough proceeds in continuous fashion
from the top to the bottom of the exchanger
body. Hence, there exists, approximately speak
a?lnity during the regeneration phase. That is
to say, if an exchanger bed has been saturated
30 with a variety of ionic constituents taken up by
ing, a dividing line or relatively narrow zone of
the exchanger in a corresponding sequence of
transition between the upper exhausted or satu
strata of the bed, when regenerant solution is
started through the exchanger bed the ?rst part
or fraction of the spent regenerant solution will
contain predominantly those ions for which the
exchanger has the lowest a?inity, and sequen
tially thereafter will contain theions for which,
the exchanger has greater ai?nity. Again, this
sequential discharge of various kinds of ions
rated portion of the exchanger body and the lower
non=exhausted or non-saturated portion of that
body. This dividing line or zone keeps shifting
downwardly through the exchanger body as the
continuously ~through-flowing ‘solution leaves an
increasing exhausted exchanger portion behind
as it advances through a correspondingly decreas
ing portion of non-exhausted or still active ex 40 is due to a chain or sequence of ionic displacement
actions, all in equilibrium with each other, where
changer. However, as the dividing line is not
by the regenerant solution displaces ?rst the ions
necessarily a sharp one, there will be noticed a
in the top strata, which have the highest a?inity
slowing down of the exchange intensity as the
to the exchanger. The displaced ions of the top
"break-throng " point of the exchanger is being
approached. This is a warning that the fresh or 45 strata in turn displace a molar equivalent of the
ions of the subsequent strata, that have a lower
regenerated exchanger should be substituted for
degree of a?inity to the exchanger, and so on
the one nearing saturation. The regeneration of
through the bed until again equilibrium is reached
a bed proceeds in a similar manner through the
as the ions available for exchange in the regen
bed.
solution will then all have been taken up
Now, after theexhaustion of the exchanger 50 erant
by the exchanger.
has proceeded part way down the bed, there will
Considering these preferential displacement or
have been formed in the exhausted portion a
equilibrium conditions, it is possible according
number of strata corresponding to various ionic
to this invention to cause the discharge and isola
constituents that are being collected in the ex
tion of ions present in a bottom strata of an ex
changer, the sequence of the strata correspond
hausted exchanger bed, by sending through the
ing to the order of a?inities of the constituents
bed a solution containing ions adapted to displace
with respect to the'exchanger. That is to say,
any of the ions in the strata above, that is'to say,
the constituent having the greatest a?inity will
by causing a displacement from the upper strata
be found to be substantially represented in the
top strata, with the other constituents following 60 of the molar equivalent of the bottom strata ions
to be isolated. Thus, if a solution is passed
in subsequent lower strata in the order of their
through the exhausted exchanger bed, containing
a?inity. As the solution continues to ?ow and
a suitable concentration of cations having a
the exhaustion proceeds accordingly, the various
greater a?inity to the exchanger than the ions
strata will appear to grow in depth until their
aggregate depth will occupy the total e?’ective 65 ‘already present in the top strata, there will take
place a corresponding molar displacement down
depth of the bed, at which time the exchange
wardly of the top strata ions, which displacement
capacity of the bed is to be considered exhausted.
_will be passed‘on through the strata further be
The depth of the individual strata is substan
low and, as a result, a corresponding molar
tially proportional to the degree of concentration
of the respective constituents in the solution. 70 equivalent of ions from the bottom strata will
eventually be discharged in the spent solution
The sequence depends upon the a?inity of the
constituents with respect to the exchanger, but
and recoverable therein as the desired fraction.
More speci?cally, let it be assumed the total
such sequence may vary with the concentration. '
That is to say, as the concentration of a constitu
ent in the solution is increased or decreased, that
depth of an exhausted cation exchanger bed con
sisted of three strata or bands of equal depth, the
2,418,701
upper one representing ions of greatest ailinity to
the exchanger, the medium one representing
ions or medium a?lnity, and the lower or bottom
strata representing ions or relatively lowest af
?nity.
It a solution were then sent downward
through the exchanger bed, the solution contain
ing solely cations or the type of the ?rst strata
and containing them in a suitable concentration
contacted with an anion exchanger bed or cell
that operates in the hydroxyl cycle. In passing
through the anion bed, the negatively charged
ions of the dissolved salts or the juice (called
anions) are exchanged for the hydroxyl ions of
the bed until the anion bed becomes saturated
with sulphates, chlorides and the like anions.
Thereupon the saturated anion bed must be re
generated by contact with some ionized alkali
‘and in a quantity representing the molar equiva
lent of the cations already present in the upper 10 hydroxide or carbonate, especially sodium hy
droxide or carbonate. During regeneration, the
strata, then the cations of that solution would
reverse equilibrium process takes place, namely,
have no e?‘ect upon the ions of the same kind or
the residual chloride and sulphate anions in the
a?lnity order in the top strata. But they would
bed exchange with hydroxyl ions or the basic re
displace the intermediate strata of lower ai?nity,
generant so that the collected negative ions or
which in turn would displace the ions of the lower
anions ?ow from the bed until the anion bed is
or bottom strata of lowest a?inity, and then the
substantially re-charged with hydroxyl ions. In
molar equivalent of the ions displaced from the
passing through the anion bed. the juice is sub
bottom strata would be found in the spent solu
stantially rid of its negative or acid forming an
tion as an isolated. fraction. In this way, by
sending a predetermined solution through the 20 ions since they have been left in the exchanger.
Thus, the basic or positive ions of the juice are
exhausted bed, a desired bottom fraction or
removed from it while passing through a. cation
the ions in the exchanger bed can be dis
exchanger bed and the negative or acid forming
placed therefrom and intercepted or isolated
ions are removed from it while passing through a
for the possible recovery of the isolated ions as
salts or otherwise. In principle then, it is only 25 subsequent anion exchanger bed. In other words,
the cations of the salts are replaced by H-ions (in
necessary that the solution to cause this displace
the hydrogen ion cycle) while the anions of the
ment have ions of greater a?inity to the ex
salts are replaced by OH-ions (in the hydroxyl
changer than the ions to be isolated, and have
ion cycle), with the net result that the salts are
them in a quantity corresponding at least to the ,
molar equivalent of the ions to be displaced.
30 replaced with HOH (or H2O‘), that is the molar
equivalent in pure and evaporable water. Other
This invention has also ,to do with beds that
substances are also removed from the juice by
make use of granular ion exchange material that
this particular treatment, that surprisingly are
is of organic nature and is of that type now new
non-ionic, such as color imparting constituents
ly called organolites in distinction from the in
organic base exchangers heretoiore known as 35 and colloids.
In a particular embodiment the invention also
zeolites. Organolites are being proposed cur
comprises a system of countercurrent regener
rently, for instance, in sugar making, a use that
ation whereby an unexpected economy can be
will now be described as an example by which to
realized with regard to the operation of the frac
convey an understanding of the ionic environ
ment of this invention, and of‘ the chemical ex 40 tionation steps proper of .this invention. The
principle of countercurrent regeneration per se
change mechanism involved in the use of the ex
changers. In extracting non-sugars and espe
cially dissolved salts from sugar making juice or
syrup, two main types of ion-exchange beds are
’ used.
has been disclosed in the patent application of
F. N. Rawlings Ser. No. 383,087, ?led March 13,
1941. Countercurrent regeneration permits of
One that is called the cation exchanger 45 far-reaching utilization or conversion of the re
bed is characterized by its use of ionic exchanger
material that operates on the hydrogen ion cycle
and is adapted to collect from the juice positively
generant solution, and in other words, makes
possible a high e?iciency of regeneration. A
spent regenerant solution that is well converted
will in turn make possible certain economies in
charged ions (called cations) represented gen
erally by-calcium, magnesium, sodium and po 50 conjunction with the fractionation of solutes ac
tassium. ' That is, as juice is supplied to the ca
tion' exchanger bed (or cell that contains the bed)
so as to pass through it and out therefrom,,ca
cording to this‘inventlon, as will be further ex
plained. Because of this importance an outline
of countercurrent regeneration is given as fol
lows:
,
_.tlons Of dissolved salts of the juice exchange
This countercurrent regeneration procedure es
themselves'for hydrogen .ions of the exchanger 55
sentially means that, in order to regenerate an
until the exchanger bed becomes exhausted of its
exhausted exchanger, the exchanger is ?rst con
exchange capacity and is so saturated with ca
tacted with a largely, but not entirely, spent so
tions that it ceases substantially to exercise fur
lution obtained from a previous exchanger treat
ther- exchange activity. Thereupon the cation
bedv must be regenerated by contact with a regen 60 ment. This solution would contain on the one
, erant-in the form of an ionized strong acid such
vas hydrochloric or sulphuric acids. During re
hand some of the salt, base or acid used for re
generation, and on the other hand some of'the
resultant products of regeneration. This solu
tion contains the unused regenerant chemical in
up by the exchanger with hydrogen ions of the 65 a relatively low molar concentration which, how
ever, is high enough to initiate the regeneration
acid regenerant so that the cations ?ow from the
of, or to partially regenerate, the exhausted ex
bed until the bed is substantially completely re
changer. Because this partly spent solution is
charged with hydrogen ions.
the ?rst one to be applied to the exchanger, it
Juice that passes from the cation bed has had
its impurity content of cations substantially re 70 shall herein be called the ?rst stage regenerat
ing solution. ~ When this partly spent or ?rst stage
moved and replaced by a molar equivalent of hy
drogen ions, but it .yet contains sulphates, chlo- ‘ regenerating solution is passed through the ex
changer the remainder of the unused regenerant
rides and other such negative ionic impurities.
chemical in the solution will have been largely
So the .juice substantially ridof its positive ionic
converted to the products resulting from regen
_ or cation impurities that have been left behind, is
generation, the reverse equilibrium process takes
place in the exchanger, namely, the cation taken
2,413,791
7
.
eration. An exchanger so treated will be per
tially regenerated.
I
8
organic' matter, or as it were, nitrogenous matter
and-notably betaine may collect in the e?luent
end portion of the cation exchanger bed in ap_
.
After the ?rst stage regenerating solution has
been contacted with the exchanger bed, the bed
preciable quantity. Subsequently therefore, such
matter will be found in relatively high concen
is given a. second treatment with a fresh regener
ating solution to complete the regeneration. The
tration in the initial portion of spent regenerant
liquor ?owing from the bed. Intercepting that
solution resulting from this completion of the
regeneration becomes the partly spent or ?rst . portion of the e?luent represents a way of iso
stage regenerating solution to be used as such in
lating and recovering in relatively high concen
the treatment of the next exchanger bed to be 10 tration such organic or nitrogenous matter.
regenerated.
More in particular, such by-product values as
What has just been desribed may be called a
betaine are thus recoverable from a cation ex
two-stage process, but correspondingly three or
changer bed through which the sugar juice is
more stages can be used. Accordingly, there may
passed.
,
be used successively a second and third stage 15
The objects of this invention are attained by
sending or recirculating spent regenerant solution
partially used regenerating solution of consecu
tively greater strength, having been subjected to
corresponding smaller degrees of conversion. The
through exhausted exchangers from which ions
tion of suitable strength.
which are to be isolated or fractionated.
or the lower strata of the bed are to be isolated.
solution used in the last stage of regeneration
This spent solution herein also termed the auxil
of this exchanger is strong enough to effectively 20 iary solution, contains a proportion of ions the
complete the regeneration of the exchanger, and
a?im'ty of which to the exchanger is greater than
this solution may be in the form of fresh solu
the affinity of the ions in the bottom strata, and
The essence of the
There
countercurrent regeneration is that the strong
fore, the ion in the auxiliary solution passing
regenerant solution is re-used by passing it in ef 25 through the bed will cause the displacement of
fect through a succession of exchanger beds in
various stages of regeneration. That is to say,
the strongest regenerant solution contacts the
least exhausted bed, while the weakest regener
ant solution contacts the most exhausted bed. 30
The regenerant chemical in the solution is ac
a molar equivalent of ion from the bottom strata
of the bed, which displaced molar equivalent rep
resents the fraction of the ions to be isolated.
This fraction can be further treated as by con
centration, or otherwise, in order to e?ect re
covery of desirable values therein.
cordingly stage-wise converted while the total
molar concentration in the solution remains sub
Some features of the invention relate to the
conditioning or chemical adjusting of the spent
stantially constant.
regenerant solution, for the purpose of obtaining
It is desirable that the exchanger bed be sub 35 a suitable auxiliary regenerant solution to effect
merged in liquid at all times, so that no air will
the chemical exchange displacement desired in
become entrapped in the voids of the bed. There
the exchanger bed to result in a desired fraction
fore, the regeneration is conducted in such a man
ation or isolation of ions therefrom. This in
ner that one fraction of the regenerant solution
volves neutralizing or partially neutralizing re
is displaced from the bed by the next stronger 40 sidual or unconverted acid or alkali in the spent
fraction. After the fully regenerated condition
regenerant solution and also adjusting the dilu
of the exchanger has been reached, the exchanger
tion prior to applying this auxiliary solution to
must be washed free of the regenerant solution
the exhausted exchanger for the purpose of frac
in it, that is to say, the remaining volume of
tionation.
strong regenerant solution that still ?lls the voids
According -to another feature the fractionation
in the exchanger, must be displaced by wash wa
of ions from an exhaustion exchanger bed, is
ter, whereupon the exchanger is again ready for
functionally coupled with a countercurrent re
use.
generation system such as above referred to, by
While the exchanger material takes up from
means of which spent regenerant required as aux
the sugar juice inorganic ions by way of ionic 50 iliary solution is obtained in a condition in which
exchange, it also takes up dissolved organic mat
ter or impurities including nitrogenous matter.
In that instance and when using for instance
such exchanger materials as organic synthetic
resins, the exchanger material is found to have 55
an a?inity or preference for the inorganic ions
over the organic matter. This order of a?inity
manifests itself in that an exhausted exchanger
bed will have accumulated inorganic matter at
the in?uent end portion, whereas organic mat
it is so well utilized or converted as to require a
relatively small, if any, amount of neutralizing
agent to condition it as auxiliary solution to be
applied to the exhausted exchanger bed for the
purpose of fractionation.
Still other features relate to the fractionation
or isolation and recovery of by-product values in
connection with a puri?cation treatment by
means of ionic exchangers of sugar bearing juices
60 or syrups. Some of the potential values recover
able from sugar juice as a source, are potassium,
ter will have accumulated at the e?iuent end por
betaine, aconitic acid and various nitrogen-bear
tion, under the condition that the flow of juice
through the bed should have been maintained for
ing matter.
.
As illustrative of a form of construction by
a period of time adequate to produce that phe
nomenon. That is to say, the exhausted condi 65 which the invention hereof may be realized, ref
erence is made to the accompanying drawings
tion of the bed as herein considered is that con
constituting a part of this speci?cation, and in
dition which results when the period of juice ?ow
which drawings:
from the bed has been long enough to have caused
Fig. 1 is a diagrammatic example of the prin
a desired quantity of the organic matter to be
accumulated in the e?luent portion of the bed 70 ciple of ionic displacement induced in the ex
changer bed, to effect fractionation of constitu
but not so long as to have caused the thus ac
cumulated organic matter to be again displaced
ents therefrom;
from the bed and into the spent liquor owing to
Fig. 2 illustrates the invention more fully as
applied to the regeneration phase of organolite
the excessive growth of the strata of inorganic
matter accumulating in the bed. In this way, 75 cation exchanger bed that has been saturated
2,413,791
9
. 10
-
with non-sucrose impurities in the process of
invention, are substantially stable in the presence
sugar juice puri?cation treatment.
So that the underlying principle of this inven
tion may
more readily understood, there is
‘shown in Fig. a general diagrammatic example
of acids and alkalis.
of how a variety of ions, for instance of the ca
tion class, range themselves'in strata in the ex- ,
changer bed, in the order of their aiiinity of
theirexchanger, and how subsequently they can
be fractionated or isolated by controlled ionic
displacement whereby the ions of lower affinity
are displaced by ions having greater amnity to
the exchanger.
‘
a
‘
»
Other suitable organolite exchangers are: The
I cation exchanger produced by the Resinous Prod
ucts Corp. of Philadelphia under the name or
identi?cation of Amberlite 1R.1, and the anion
exchanger Amberlite 1R.4 from the same source.
The invention is represented in Figure 2 in
connection with the regeneration phase of a ca
tion exchanger of the organolite class,‘ the ex
changer bed being designated as B. However, it
is to be understood that the invention can be
applied as well to an anion operating cycle, and
Referring to Fig. 1, let 50% of the capacity of Y also in connection with the use of zeolites.
A solution such as sugar juice containing a
a fully exhausted exchanger bed \be saturated 15
with Na-plus Ca-ions, corresponding to half the
mixture of solutes or non-sucrose impurities is
assumed to have passed through the exchanger
bed B leaving the bed in the exhausted condition
a. Let the lower half of the bed X be saturated
indicating in Figure 2 that various ionic constitu
with K- and with NHa-iOns so strati?ed that K
occupies a stratum or band b of 25% of the depth 20 ents have been taken‘up by the exchanger in con
secutive strata in the order of their a?lnity to the
of the bed, and NH: occupies the remaining 25%
exchanger. By way of example, the exchanger
below.
‘
_
bed is herein shown to have the top stratum satu
Let'it further be assumed that another ex
rated with Na and Ca ions, and to have potassium
changer bed Y of equal capacity be saturated and
exhausted throughout with Na-plus Ca-ions from 25 (K), ammonia (NHs), and betaine, respectively,
in the strata below. The aggregate depth of these
a previous operation. If this bed Y is then re
strata represents the total depth of the exchanger
generated with _HCl solution design‘ ted as S,
bed.
then the spent regenerant liquor ?o ing from
depth of the bed represented by the top stratum
The constituents K, NHa, and betaine, present
the bed may be considered as ti?ztliary solu
tion since it contains all theNa p/s Ca which 30 in the respective three lower strata arethe ones
to be fractionated or isolated eitherin bulk or
it has displaced from the bed i/
change for H
each of them individually. That is to say, de
ion. If 50% total Na-plus Ca-ions removed from
pending upon how the fraction of fractions are
the exchanger bed Y and present in the spent
to be intercepted in the spent liquor ?owing from
regenerant solution R is then sent downwardly
the
exchanger bed, one may visualize either a sing
35
through the exhausted exchanger bed X, it will
gle fraction being intercepted that contains all
pass substantially inertly through the upper
three constituents, K, NHa, and betaine, or each
stratum a because ‘of the presence therein of the
of these constituents as being intercepted as an
Na and Ca. But in passing through the further
individual fraction. Other possible variations are
strata b and cit displaces therefrom the K- and
to-have the betaine isolated in the ?rst fraction,
NHfi-iOHS because of the greater a?‘inity of the 40 and the NH: and K together in a following frac
Na and Ca to the exchanger. The displaced K
tion, or vice versa, the betaine and the NH: might
and NHs-iOl’l will then be found present in the
be'isolated together in a ?rst fraction, with the
spent solution flowing from the exchanger bed _ K alone to follow in the subsequent fraction.
X: as the bed X is left fully saturated with Na
If the betaine, which is substantially present
and Ca and thus in a condition to be regenerated
in the bottom strata of the exchanger bed, is the
with HCl solution and utilized in the manner of
sole value sought to be isolated and recovered,
bed Y in a subsequent operating cycle. The dis
then a corresponding ionic displacement must be
placed K- and NHa-ion are represented as volume
effected for recovering just that constituent in
F in terms of spent solution, and that volume 50 a corresponding fraction of intercepted spent
represents a fraction comprising the K- and NH;
ion desired to be isolated.
The ?ow-sheet of Fig. 2 illustrates the inven
tion as applied to the problem of fractionation or
by-product recovery incident to the ionic puri?
cation treatment of sugar juice by means of or
ganolites, that is the isolation of values from the
impurities removable from the juice by the ionic
exchange treatment.
-
‘
liquor.
,
Since the isolation of‘ the three constituents
each individually-K, NH:;, and betaine—is here
in taken as an example, there are consequently
provided three interceptor or fractionation tanks
III, II, and I2, to receive the respective fractions
of spent liquor.
Furthermore, there are provided tanks l3, l4,
l5, I6, for receiving regenerant solution in various
One of a variety of organic cation exchangers 60 stages of conversion,- such as occur in the prac
considered suitable for the present purpose is of
tice of counter-current regeneration aforemen
the resinous type such as exempli?ed in the
tioned. In this system, tank l3, for example, re-v
United States pa nt to Holmes No. 2,191,853,
ceives a 5% fresh regenerant HCl solution, tank
where the excha ger is described as a synthetic
I 4 a partially converted or once-used regenerant
resin of the polyhydric phenol formaldehyde type 65 ‘solution obtained from a‘ previous regeneration
which is sulphited to a degree such that its sul
phur content is not less than 2.4%. An'organic
anion exchanger considered suitable for the pres
cycle, tank IS a still further converted or twice
used regenerant solution from a previous regen
eration cycle, and tank IS the spent regenerant
ent purpose is also of the resinous type and is
solution containing residual unconverted chemi
exempli?ed in the United States patent to Adams 70 cal too dilute for use in a. further regeneration
and Holmes No. 2,151,883, describing the ex
cycle. For example, in counter-current regen
changer as an insoluble resin-like product ob
eration a 5% HCl regenerant solution may be
tained by the reaction of formaldehyde with an
convertedto about 1 to 1.5% HCl content with
aromatic amine. Exchangers of the type con
regeneration of the bed proceeding effectively.
templated for use in connection with the present 75 whereas straight regeneration (that is regenera
2,418,791
12
iion of an exhausted exchanger bed directly with
fresh or strong 5% regenerant solution) could by
tion serves as auxiliary regenerant solution in the
fractionation steps, the balance to be discharged
comparison be carried only to about 2 to 2.5%
H01 content in the spent liquor. The spent re
generant solution, according to this invention,
from the system through line 44. Valves 45, 48,
41, also connected with the header 40a admit
spent liquor fractions containing K, NHz, and
serves as an auxiliary regenerant solution for ef
betaine respectively into the interceptor tanks l0,
fecting the ionic displacement from the exhausted
II, and I2 respectively, which tanks in turn are
exchanger bed B of one or more fractions repre
provided with bottom discharge valves 5|, 52, 53,
and with corresponding discharge connections
senting di?erent ionic constituents. This dis
placement is e?’ected due to the contents in the 10 51a. 52a and 5311. There is also provided a tank 54
to receive used wash‘water from the exchanger
spent or auxiliary regenerant solution of a pro
bed, through the header 40a and a valve 55. The
portion of ions of a higher order of a?inity to the
tank has a. discharge valve 56 and discharge con
exchanger than is possessed by the ionic constitu
nection 51. A goose-neck G through which the
ents to be fractionated from the exchanger. The
liquid discharging from the exchanger bed B must
interceptor tanks III, II, and I2 may be oper
pass, is so designed as to normally insure sub
ated to receive the spent liquor fractions contain~
mersion of the exchanger material at all times.
lllg the K, NH3, and betaine respectively.
The goose-neck G has a vent 58 to break the
There is further provided a tank 20 to which
syphoning effect thereof.
the spent regenerant solution from tank Hi can
be transferred after the residual regenerant 20
Operation
chemical (HCl) has been neutralized, and other
Inasmuch
as
the
principle
of ionic displacement
wise conditioned as with respect to its dilution, so
herein employed will be clear from what has been
as to serve more effectively as the auxiliary re
said in the foregoing with respect to Fig. 1, it will
generant solution. Hence, there is also shown
suffice to describe the operation on the basis of
a measuring tank 2i for dosing a neutralizing
the ?owsheet in Fig. 2 pertaining speci?cally to
agentsuch as an acid or an alkali as the case
an example in which an organolite cation ex
may be, and a measuring tank 22 for diluting
changer is exhausted incident to the puri?cation
water. A measuring tank 23 supplies the required
treatment of sugar juice, whereby dissolved non
dose of fresh regenerant acid (HCl) to make up
the fresh regenerant solution in tank l3.
30 sucrose impurities or salts are removed from the
juice, that is to say, sugar juice has been passed
A header 24 supplies regenerant solution in
downwardly through the cation exchanger,
consecutive stages from the various tanks I3, l4,
whereby the exchanger has become saturated with
l5, and 20, by means of a pump 24a to the top
a variety of cations in strata corresponding to
of and onto the exchanger bed B, connections
the ailinity of the respective cations to the ex
being provided between the header and the re
changer. In this example Na- and Ca-ions are
spective tank bottoms. A discharge control valve
found largely in a top stratum of appreciable
25 is provided for the fresh solution tank l3, a
depth, while the strata below are represented by
valve 26 for discharging once-used solution from
K, NHa, and betaine respectively. At this point
tank l4, and a valve 21 for discharging twice-used
solution from tank l5. A valve 28 is provided for 40 of the operating cycle the tank 13 should be
assumed to have been ?lled with the required vol
discharging neutralized spent liquor (that is
ume of fresh acid (HCl) regenerant solution of.
auxiliary regenerant solution) from tank 20 to
say, 5% concentration. At the same time, tank
the exchanger bed. Wash water for the ex14 is assumed to be ?lled with what is herein
changer bed can be admitted into the header 24
45 called once-used regenerant solution such as has
through a valve 21A.
been obtained from a previous operating cycle.
Provision is made for the spent liquor solution
and tank I 5 should be‘ ?lled at this time with
from tank I6 to be transferred through a con
twice-used regenerant solution, also obtained as
trol valve 29, a pump 30, pipe connections 3| and
such from a previous operating cycle. Tank [8 is
32 and another control valve 33 to the tank 20.
A portion of the spent regenerant solution from 50 emptied at this time, but tank 20 is ?lled with
spent regenerant solution from a previous cycle,
the cyclic system is sent to waste through a dis
which spent solution according to the invention,
charge connection 34. The admission of a regu
should have had its residual or unconverted acid
lating dose of alkali into the measuring tank 2i
(HCl) neutralized and its dilution adjusted so
is controlled by a valve 35, and into tank 20 by a
valve 36. The admission of diluting water into 55 that it represents auxiliary regenerant solution
suited to the exchange characteristics of the ex
the measuring tank 22 is controlled by a valve 31,
changer and for the present purpose of fractiona
and into the tank 20 by a valve 38. The admis—
tion which is the object of this invention.
sion of fresh make-up acid (HCl) .into the meas
At this time the voids in the exchanger bed B
uring tank 23 is controlled by a valve 39, and into
the tank 13 by a valve 40.
60 are assumed to be ?lled with residual wash water
which now must be displaced downwardly from
Furthermore, there is provided a supply header
the bed incident to the passage therethrough of
40a for admitting regenerant solution in various
the neutralized spent regenerant solution. The
stages of conversion, leading from the bottom of
displaced wash water may be intercepted in tank
the exchanger bed to the respective tanks I3, [4,
l5, and I 6. The admission of strong solution into 65 54 into which it can be admitted through the
valve 55. At the proper time the ?ow of liquid
tank I 3 is controlled-through a valve 4|, and the
discharging from the exchanger bed is switched
exact source of this strong solution or of por
to and through the valve 45 into the ?rst inter
tions thereof will herein be further explained.
ceptor tank It], that is, when the residual wash
Once-used solution from the exchanger bed is
supplied to the tank I! through a valve 42, to be 70 water has been displaced and the spent liquor
further utilized in a subsequent exchange cycle.
' fraction containing the betaine begins to flow
from the bed. In this way, the betaine-contain
Twice-used solution is supplied into tank I5
through a valve 43, also for use in a subsequent
ing fraction of the discharging spent liquor is in
cycle. Spent regenerant solution is supplied to
tercepted in tank III until the content of the dis
tank l6 .through a valve 44, part of which solu 75 charging liquor begins to change from betaine to
‘2,413,791
solution ' as ‘auxiliary '
the discharging spent liquor is switchedthrough
solution for '
pump 30 through lines 3| and .32 and through
valve 33 into tank 20 where the residual uncon
verted acid (HCl) inv it is neutralized with a suit
able alkali from the measuring tank ii, and the
solution diluted,‘ if desired, from the measuring
'now the out?owi'ng“ NHaécontaining "fraction ac
cumulates. In a vsimilar manner the. flowis then
again switched throughva-lve '4], into thethird
interceptor tank l2 in which to accumulate the
tank 22. The balance of the spent regenerant
K-containing fraction of the spent liquor. When .
10 solution coming from the tank [6, andnot needed,
this latter fraction has been substantially inter
’cepted, the flow from tank 20 of auxiliary re
-'
regenerant
effecting the fractionation as above described, is '
- sent through discharge-valve 29 by means'or the
'- ’ valve“ into the second interceptor tank H where
>
-
14
' '- Nmwmtnls the next constituent to be inter_ 1
vcepted- and isolated. . Consequently, at this point
.
begins to discharge from the system as indicated
by the line“, The discharge line 34 is formed
with a gooseneck J through which spent regen
generant solution through-the bed is stopped, as
> the exchanger bed 'will now have ‘been saturated
1_..substantially through its entire depth with Na
erant solution from tank I6 begins to ?ow when
? - and Ca-ions assumed to have been present in suf
- ' i‘lcient quantity in the auxiliary regenerant solu
15 the valve 33 is closed while the pump 30 ‘continues
tion-to effect the displacement and fractionation
running. The goose-neck J has a vent 34a to
break the syphoning 'e?ect thereof. The spent
ofthe-K, NHs, andjbetaine as-just described. '
regenerant, solution that has been conditioned ‘
._ , -,From what has beenusaid‘ before about the ‘ into neutralized spent solution in tank 20 is then
' J im'e'chanism of successive displacement ,e?ects in 20 ready‘to be used over again as auxiliary regen
erantsolution in a new ‘cation exchanger oper
- ' the exchanger bed B, ‘it will be understood why
, ating cycle.
~
‘
- thefractions representing the various constituents
Since through dilution (note the regulating
vdischarge from thefbed in the‘ order described.
That is tosay, the Na- and Ca-ions su?iciently
;
water valve 31) one may vary the relative a?‘inity '
of the ions in the auxiliary regenerant solution
with respect to the exchanger, it can be visualized
that by such control the ions in the auxiliary
‘regenerant solution may be assigned a desired‘
' -'juice puri?cation treatment, but in continuing
'_ place in the order of a?im'ty. Consequently, such’
' ' 1 downward through the bed, they ?rst displace the
control or vamnity adjustment should make it
-’ _ K-ions which in turn displace the NHv-ions in the ‘
v:rmss‘ible to leave una?ected any desirable dept
., . next stratum,.passing the displacement further
of the exchanger, and to havev the chemical dis
- '1 ontothe-betaine in the bottom stratum, causing
present in the auxiliary solution pass inertly
through the upper strata of the exchanger, al
ready saturated with 'Na"-- and 021,- from the
placement action take?place, for instance, only
» ' the betaine eventually to emerge from the bed as _
when the auxiliary regenerant solution substan- >
the'?rst‘fraction'to be intercepted in tank i0.
tially reaches the particular strata containing.
'_ ‘By virtue of the same displacement mechanism,
.the fraction of ions or moleculesto be displaced.
. l J the'next spent liquor fraction containing the NHs,
'It is thus visuaiizedithat the auxiliary regenerant
‘
, and thethird spent liquor fraction containing the
solution should ?ow substantially'inertly (that is, ->
- K, are successively intercepted in tanks II and v_ [2 respectively. Finally, when all'three frac
. ‘' tions'have been displacedand intercepted, sub
~10 v
_' :stantially the entire depth of the bed will be
,'_ found. to have become saturated with Na and Ca.
The'intercepted fractions in the tanks III, II and
without exerting displacement or exchange func
tion) through that depth or strata of- the bed;
that overlies that strata containing the ions or
molecules to be displaced as a recovered fraction.
In other words, in this way one may control or
. predetermine the point of depth in the bed, at
.i2 can' .be, individually concentrated for the re
" ‘covery of the respective values or salts.
45 which or fro-m which on, a desired displacement
action by the auxiliary regenerant solution should
vvIf the molar equivalent needed for displacing
'_ \thefthre‘e fractions K, NH; and betaine, is known, '_
be
effected.
'
>
.
,-
,
'
.
The twice-used or largely converted regenerant
' ' then it is possible to predetermine the volume and
.‘char'a'cter' of the auxiliary regenerant solution,
[that is, the neutralized spent regenerant solution
solution from tank I5 passing through the bed
have caused the initial regeneration of the
exchanger bed with I-I-ion. Any of the residual
50. will
(‘which must be sufficient to effect the desired dis
placement and fractionation. Following directly
.iupon this auxiliary solution e?ecting fractiona
tion, there is then passed through the exchanger
second-used solution in the bed is then followed
up with and. displaced by once-used, that is, less
converted, regenerantv solution from tank H, in
Ijfbed the twicesused ' (that is. largely converted)” 55' order to furtheradvance the regeneration of the,
exchanger bed. Consequently, there will now ?ow
1-regenerant'solution from tankv l5 from which it ,
is‘drawn thru the valve 21 by the pump 24a.
» from the. bed a solution equivalent in HCl strength
This twice-used solution will displace from the
to twice-used-solution and as such it is discharged
through valve 43 into the now emptytank l5. '
.3. bed ‘any of the'aforer'nentione'd spent liquor frac
The residual solution from. thisregeneration
'' ,tions or else any excess or residual unconverted 60
~
strong regenerant solution from tank l3>to ?nish.‘ ; :
'- emergesirom the bed as'true spent regenerant ,
‘solution which as such will containv largely Ca and
~ ~Naas chlorides due to initial regeneration now
taking place inthe bed to the extentJthat the
~_H—'ion's ‘of the regenerant acid '(HCl). ‘are avail
‘ ablein-the twice-used regenerant solution;
This
bre'ak 'or-‘interception means that: what new
?owingfrom the bed when this final regen-v'
6,5 now
crant solution emerges with the HCl content reduced to what is, equivalent to once-used solution, . ' ' 1
and as such, it is sent to the new empty tank _'
it for use in a subsequent operating cycle, while
being followed up with and displaced by wash
twater?from the header 24. _ However, when the
-
‘ regeneration of the exchanger bed from'top to
-' .valve 44 into the-empty spent regenerant solution
tank .l6.
.
'interception’is
the regeneration
made
of the
with
bed.
respect-to
Again the
the break
solution.‘
or - '~' . ~_ _
~_-Y_lemerges from .the bed as'true spent-‘regenerant
solution is'sent through the header Mia-and the
'
._
v
..
v
_
‘:"I'he portion needed of this spent. regenerant
,
step is then displaced from the bed by .‘fresh or “
' auxiliary regenerant solution. Again the break
or interception is made with ‘respect to the liquid
" discharging from the bed, when'the ‘spent liquor
bottom is thus-completed in this last step, the
voids of the‘ .bed will still be. ?lled to some ex
‘tent with trailing unconverted HCl solution which,
9,418,791
15
-
with the wash water, forms a weak solution. By
continuing to pump wash water this weak solu
tion is displaced from the bed and supplied
through the header 40a, and valve 4| to the fresh
solution tank I3 until the tank is filled to its
predetermined mark. _Fresh make-up acid is then
added from the measuring tank 23 to bring it
up to the strength required for the fresh regen
erant solution.
'
16
lution containing dissolved nitrogenous along with
ionized inorganic non-sugar constituents to e?'ect
the isolation of nitrogenous constituents, which
comprises passing the solution through a quan
tity of granular hydrogen ion exchange material
substantially saturated with H-ions so that in
organic constituents are retained in the in?uent
zone while nitrogenous constituents are retained
in the eilluent zone of the material approximate
The use of counter-current regeneration in con 10 ly until nitrogenous~ constituents start to pass
from said eilluent zone, then passing through said
nection with this invention makes it possible to
eiiluent zone an auxiliary solution of substantially
conduct the step of neutralizing the spent regen
the same composition as the regenerant solution
erant solution with a high degree oi! economy.
later produced to displace nitrogenous constitu
That is to say, since the regenerant chemical
(HCl) has been converted to a particularly large 15 ents in said eiiluent zone by inorganic cations,
extent by counter-current operation, the small
residual unconverted HCl portion in the spent
regenerant solution requires a corresponding but
small quantity of neutralizing agent. However,
isolating a resulting eiiiuent portion containing
the displaced nitrogenous constituents for the
recovery of such constituents, and regenerating
the exchange material to restore its H-ion ex
-it is within the scope of this invention that the 20 changecapacity by passing therethrough as acid
neutralizing or conditioning step be dispensed
with, and the true regenerant solution from tank
l6 be used-as such, that is substantially without
regenerant solution, whereby therev is produced
an eilluent of substantially spent regenerant solu
tion substantially in the nature of said auxiliary
solution.
chemical adjustments, to serve as the auxiliary
2. The process according to claim 1, in which
regenerant solution either with or without addi 25
the organic constituents isolated are derived irom
tional controlled dilution thereof.
the cation exchange material and comprise sub
While the invention so far has been described
stantially betaine.
substantially on the basis of the chemical mech
3. The process according to claim 1, with the
anism that controls straight ionic vexchange or
ion displacement effects taking place in the ex 30 additional steps of neutralizing unconverted acid
regenerant chemical in ‘said auxiliary solution
changer, it is to be understood that the displace
prior to contacting the solution with the exchange
ment or fractionation, to be effective according
material.
to this invention with the aid of spent regenerant
4. The method according to claim 1, with the
solution as an auxiliary, may also include con
stituents which do not exactly follow the law 35 additional step of diluting said auxiliary solution
to effect a desired degree of concentration of the
herein set forth of selective or preferential ionic
solutes therein prior to contacting it with the
exchange. That is to say, some values to be
exchange material.
fractionated from the exchanger may be found
5. The method according to claim 1, in which
to have been absorbed directly, that is, in their
molecular state, by certain strata of the exchang 40 the regeneration is effected by ?rst passing
through the exhausted material partially spent
er, and it is observed that somehow these con
regenerant solution obtained from previous re
stituents have a place in the order of a?inity
generation whereby largely spent e?luent liquor is
obtained, and then passing through it stronger
their place at the end of the line, namely, after 45 regenerant solution, in which said auxiliary so
lution comprises a quantity of said largely spent
all true ionic exchange has taken place in the
liquor, with the additional step or neutralizing
exchanger, and consequently such constituents
any unconverted acid regenerant chemical in said
may be found in the bottom portion or strata of
auxiliary solution prior to contacting the solution
the exchanger bed whence they may be most
.
readily removed or displaced by the treatment 50 with the exchange material.
with respect to the exchanger. In some cases,
such molecular constituents will appear to take
method according to this invention.
‘
I claim:
1. The process of treating a sugar-bearing so
RALPH w. SHAFOR.
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