US1256952A - Recovery of sugar from molasses. - Google Patents

Description

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To all whom it may concern:

Be it known that I, FRITZ TIEMANN, a

subject of the German Emperor, residing at Berlin, W., 259 Kurfiirstendamm, Germany, have invented certain new and useful Improvements in and Relating to the Recovery of Sugar front Molasses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as Will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in processes for recovering sugar from molasses of any origin.

It has not been possible to apply any of the existing processes for recovering crystallized sugar from the molasses resulting from the manufacture of beet sugar to molasses resulting from the manufacture of cane sugar, because the latter is much more impure than sugar beet molasses, and because the Working expenses would be greater than the profits, as the required compounds of lime, strontia or baryta are too expensive.

It is a well known fact that certain substances dissolved in water may be recovered in a solid condition by adding certain other substances which are soluble in water, to the solution, the said added substances precipitating or causing former substances from the solution.

Further it is a scientifically established fact that cane sugar may be expelled from an impure solution containing salts by adding levulose or dextrose (glucose) or a mixture of both kinds of sugar, '13. e., invert sugar to these saline sugar solutions. utilize the aforementioned scientifically established property of dextrose for recovering' crystallized sugar from molasses when working one large commercial scale, so as to obtain an increased yield of sugar. The commercial dextrose available for this purpose, however, only contains about of actual dextrose, whereas the remainder of about 40% consists of dextrins and the like, which, as is well known, have a very injurious and detrimental effect on the crystallizing out of the sugar, as they are instrumental in the production of molasses. As the dextrose is usually produced from starch flour and the like, it will be seen that according to this proposal a product must be added to the molasses whichoriginates from any desired degree of inversion of the sugar quite a difi'erent industry.

Specification of Letters Fatent.

invert sugar of expelling cane sugar the crystallization of the Further it has already been proposed tov -molasses from sugar cane, vplled wlth advantage to molasses from sugar Patented ll cb. 19, 191%..

Application filed 311111225, 1914. Serial No. 847,314.

This scientifically established property of impure solutions is now to be utilized for recovering crystallized sugar from molasses which constitutes an impure saline solution of sugar and which already .'contains invert sugar. This is e'fiected in accordance with the present invention, by adding artificially produced invert sugar to the molasses, the said artificially produced invert sugar being preferably produced in the manner hereinafter described.v The invert sugar produced from one portion of the molasses may thus be used for the separation (precipitation or crystallization) of the cane sugar contained in another portion of the molasses.

This recovered sugar may be separated in the form of sugar powder, in case molasses not containing crystals is treated, whereas from if the molasses already contains sugar crysartificially produced invert sugar thereto either after evaporation, or at any other stage before the said centrifugal separation or a part of the necessary quantity may be added at one stage and a part at another stage, so long as the necessary quantity (depending upon'the composition of the molasses treated) be added. The invert sugar used in this process may most conveniently be obtained by centrifuging a residual or by-product masse-cuite .without the addition of invert sugar, by inverting the molasses removed therefrom and by adding the same as described above to other boiled liquors of the same residual or by-product masse-cuite.

This process for recovering sugar from molasses which is particularly applicable to may also be apbeets, where this is permitted by the econoinlcal and industrial conditions.

Further, it has been found that the inversion of the dissolved sugar in-the molasses up to about one third of the said sugar takes.

of ease and within place with the greatest a short time, whereas the inversion-of the remainder of the sugar in the molasses takes place only incompletely and only aftep a long time. Further, as it is possible by regulating the temperature and time, to obtain it is possible, ininverting one portlon sugar contained therein the molasses, therefore stead of completel of the molasses or t e in, to subject the whole mass of the molasses ha'sproved itself very advantageous in'cons for instance the 80 I increased to 95 C., and at 95 C. 25.

. nection herewith. i

The molasses which has been diluted to a sufficient extent (to about 45 Brix), is strongly acidulated byintroducing an acid, while the temperature is being gradually is allowed to stand or is stirred for a shorter or longer period depending upon the required degree inversion. As soon as the inversion of of the sugar in the molasses. has been attained, which takes about 5hours, the inversion is -Iested by seeolgng the; mass to a temperature below his cooling is effected immediately on s5 the transference of the partly inverted solution of A v in order to boil the same down to a. concenmolasses to the vacuum apparatus,

' tration of masse-cuite. Y

The boiling of the molasses, so as. to convertthe same into masse-cuite is carried out at a low temperature and in' vacuum, the

. sible to effect simultaneously a refining purification of the snlfat like.

molasses being treated alone, or in the presence of sugar crystals which promote crys 'tallization. 7 I

- -By extracting the sugar from the molasses accordmg-to theimproved process, itvis posor solution by using-suitable inversion a ents.

an economical as well as from achemi-techical point of view. a

A large [number 'of purifying or refining agents have been proposed for sugarsolutions', which parse possess great purifying properties, such as for instance aluminum mono-calcium phosphate and the ""uch purifying agent's, however, when used for working on an industrial scale,' do

produce the desired result ciab e purifying effect is obtained'only by using large quantities of after the-alkalis or neutral sa solutions have been removed.

ese substances ts of the sugar Under these the desired degree of in,-, that is to say until, the required a simple regulation of the desired degree of inversion,

The puri ying'or refining ofsugar sold-- j tions constitutes an important problem from as an appreusages conditions, however, efifect a strong inversion of the sugar takes place in the solutions, which, however, must be avoided in any case, for which reason the employment of these proposed purifyingor re g agents on a large scale has been discarded.

.According to a fu besides the purifying rther development of,

the improved process, however, such agents A Y may be employed, for

I recovering sugar from molasses, m

such; quantities that a portion of the sugar is inverted, whereby the same object as described above is attained, and a further recovery of sugar through the great purifying effect, is eifected in combination with the inversion. Although the avoidance of the employment of these measures may be justified 1n connection with purer sugar solutions from which the sugar is recovered in a crystal lized form by simple concentration by evaporation, itis a matter with advantage to the by-productliquids resulting from the manufacture of sugar, 2'. e., the molasses, as the sugar destroyed in connection'therewith'by inversion was previously unrecoverable from the molasses, whereas now the inversion of larger amounts of the sugar renders more of the sugar in the molasses recoverable in' the formof crystals.

of surprise that these purifying or refining agents may be applled The purifying 'action of the 1 agents employed now no longer vefl'ects solely the crystallizing out of the sugar from the molasses, but the invert sugar artificially formed or freshly introduced in-the case of" sugar cane juices, causes the separation of a further portion of sugarfrom the solution of molasses in a crystallizable form, and the detrimentaleflecfiof the residuesof the salts which cannotbe removed by agents is eliminated in consequence of the salting out efiect of the invert sugar in 1 mpure solutions of sugar.v The degree of inversion produced by thepurlfymg agents employed difl'ers, depending upon the nathe purifying s ture of the salts in the molasses, and may be practically determined for the various kinds of molasses, so as to obtain the desired .pro-

portion of sugar, salts and invert sugar for producing the most favorable results.

-. Either only one portion of the molasses is treated with the purifying agent and completely inverted, a tion of untreated molasses, or the ent 1re bulk of the'molasses is only partially inverted to the desired degree'gby the pur fying agents. The desired degree of -invers1on of molasses may be easily regulated, no matter what the proportions are, as the salts cond added to another portained in'the molasses exert a preventative protecting effect, and for obtaining an appreciable tions are inversion high temperatures above those required for normal working- 001N117." ce y mp y p r yi sl fication.

'with or without the currents of steam of high pressure. When lowering the temperatures below 90 0., or when dispensing with the introduction of steam, an appreciable inversion ceases even during the subsequent boiling in the vacuum apparatus.

gMineral acids for instance, sulfurous acid (80,), phosphoric acid and their salts or acid salts, for instance, aluminum sulfate A to be used as purlfylng or refining agents for the molasses for the purpose of effecting a simultaneous inversion of the same.

The following is one form of carrying into effect the improved process for recovering sugar from molasses:

The molasses is diluted to 45 Brix, heated to a temperature of'lOO C., neutralized and for the purpose of effecting the inversion is mixed with a sufficient quantity of a solution of aluminum sulfate or calcium acid, phosphate,

and thereafter steam from a. boiler is introduced into'the molasses;

After four to five hours a suiiicient inversion (in the case of molasses from sugar cane juices, a suflicient increase in the invert sugar) is, produced in addition to the puri- Thereafter the solution of molasses inverted to thedesired extent is separated from'the precipitated or deposited materials by filtration while in a hot con-.

dition.

In cases where the inversion has advanced too far, the solution is adjusted to the desired proportions of sugar, salts and sugar by adding untreated molasses to the same. The solution of molasses is concentrated by evaporation in the usual manner, addition of other sugary products of the sugar manufacture, and is allowed to crystallize. Y

Further it has. been found that the invert sugar added to the molasses for the purpose of extracting the sugar therefrom renders recoverable a greater quantity of sugar than corresponds to 1ts own weight.

' of inversion may For thisreason therefore the process may be modified so that instead of lnverting a portion of the sugar contained in the molasses, which heretofore was unrecoverable a corresponding weight of sugar of any origin is inverted. This invert sugar or the invert sugar solution is the whole mass of molasses. By means of this expedient the whole process of extracting the sugar from the molasses is considerably simplified, as the inversion of sugar is more rapid, and more uniform. Further time is saved, and the'machinery required is simplified The processes described hereinbefore for recovering sugar from molasses by means be applied to the molasses the manufacture of beet in a solid form,

resulting from or mixtures of these are adapted from molasses,

invert aration, in solid form of cane sugar economical, more restricted to sugar produced from sugar cane.

I declare that what I claim is: 1. A process of treating cane sugar molasses which comprises eifecting' the separation, in solid form,

of cane sugar. from the molasses, by adding to said molasses, an amount of dlssolved invert sugar sufiic'ient to cause the separation of at least a material proportion of the cane sugar content thereof.

2. A process of separating cane sugar which comprises converting a portion only of the cane sugar contained in said molasses, into invert sugar, and thereafter allowing contact of said invert sugar and the remaining cane sugar, at a temperature below that at which further cane sugar would become inverted, until at least a portion of the unconverted cane sugar separates from the molasses, in solid form.

3. A process of separating cane sugar from molasses, which comprises boiling at leasta portion of the molasses with purifying agents capable of inverting cane sugar, until a portion only of the cane sugar of the entire amount of molasses has become inverted, thereafter cooling the so treated portion of said molasses and allowing the sepfrom said molasses.

4. A process of recovering cane sugar from molasses which comprises dividing the .molasses into portions, boiling one portion of the molasses with an acid reagent capable of inverting the bulk of the cane sugar therein, adding the so treated portion of the molasses to another portion of the molasses andcausing cane sugar to separate, in

solidform, from said molasses.

5. A process of separating cane sugar from molasses which comprises converting a portion of the cane sugar-therein into invert sugar, and removing at least a portion of the soluble salts from said molasses, to produce a ratio of cane sugar, invert sugar and salts, favorable to the separation. of cane sugar from said molasses.

6. In the separation of cane sugarfrom molasses, the step of salting out cane sugar,

from the molasses by the addition thereto.

of a quantity of invert sugar which is free from large quantities of dextrin, and which quantity is sufiicient to cause separation in solid form of a considerable proportion of the cane sugar content of the molasses.

'7. In the separation of cane sugar, the

steps of boiling the molasses with purifying of the dissolved sugar to producea ratio of agents capable of inverting a portion of the sugar, salts and invert' sugar, suitable for 25 cane sugar in said molasses, and capable of the separation in solid form of a' portion of removing soluble salts from said molasses, the contained cane sugar, whereby through lowering the temperature of the molasses the working of thepurifyingagentsas into below 80 0., and thereafter separating verting agents, and thesaltingoutjaction of out solid cane sugar from said molasses. the produced invertsugar, the production 30 8. In the recovery of solid cane sugar of solid cane sugar from the molasses is effrom molasses the steps of converting a fected. portion ofthe cane sugar therein into in- 11. In the recovery-"of'sugar from rnovert sugar, and removing a portion of the lasses, the herein described improvement soluble salts, concentrating the molasses at which comprises inverting a quantity of 35,

a temperature below 80 0., and separating cane sugar, and adding'the same to-the'mocane sugar, 1n solid form, from sald molasses in such proportionastocause the seplasses. ara tlon, in SOlld form, of a large amount of 9. In the treatment of molasses, the step the cane sugar content oflthe molasses.

of recovering cane sugar by inverting the Intestimony whereof I have afiixed my 4 sugar contfiznt oflmolasses, and adding the signature, in presence of two witnesses same to 0t er mo asses. 1 r

. 10.,A process of treating molasses which a a EMA comprises subjecting'the same to the action Witnesses: v r a a 7 of purifyin agents in such amounts that W'oLnEMA HAUPT,

there is produced an inversion of a portion HENRY Hnsrnm