US325349A - Louis lefbaxc - Google Patents

Description

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LOUIS LEFRANO, OF TEACY-LE-VAL, FRANCE.

PROCESS OF EXTRACTING SUGAR FROM'JUICES, SIRUPE, 80C.

EPECIFICATION forming part of Letters Patent No. 325,349, dated September 1, 1825.

(No specimens.)

To all whom it may concern.-

Be it known that I, Louis Lnnnanc, a citi zen of the Republic of France, residing at Tracy-le-V al, in the said Republic, have invent-ed a new and Improved Process of EX- tracting Sugar from Juices, Sirups, and Molasses, of which the following is a specification.

It is well known that when thereis dissolved in a saccharine solutionaqnantity of lime sufticient to saturate the sugar which is contained in the solution a soluble sucrate of lime is formed. If this solution of sucrate of lime is subjected to the action of heat, there is obtained an almost insoluble solution of another sucrate, corresponding to the formula of tribasic sucrate, (O,. ,H,,,O,,30a0.) The formula of this reaction appears to be the following: 3 (O,, ,H,,O,,20a0) 2 (O,.,H,,O,,30a O)+ C,,H,,O,,. This sucrate is separable when heated by filtration from its mother-waters. The sugar can be disengaged from it by causing the lime to pass into an insoluble state or utiliz ing it for the purification of saccharine juices and sirups. The inconvenience of this process will appear from the preceding formula.

The transtormation of sugar into tribasic sucrate is never complete. It is then necessary either to recommence and repeat many times the preceding operations upon the liqold as it becomes more and more spent, or else l toresort to the process of substitution. \Vhatever may be the value of these two systems, it results clearly from the preceding formula that this process of extraction of sugar does not give good results, except when the quan tity of sugar in the liquid is quite considerable-that is to say, from five to twelve per cent. of sugar.

It isalso well known that there has been applied to the extraction of sugar from juices, sirups, and molasses the following process, which consists in dissolving in the saccharine solution a quantity of lime suiiicient to produce a saturation of the sugar which the so lution contains corresponding with the formation of the bibasic sucrate, afterward to add to this solution a certain quantity of the salt of lime in solution, corresponding with the quantityof lime which is lacking to obtain an insoluble sucrate, and to add to the mixture an alkaline base. By this process there is obtained cold a precipitate of bibasic sucrate of lime by virtue of the reaction 3 (O,,ll,,O,,2GaO)+ GaOl f NaO 3( O,.,H,,O,,3Gat)) NaCl, in the case, for example, of the employment of chloride of lime and of soda. This process, which the above theoretic formula indicates as perfect in the sense that all the sugar will be completely transformed into insoluble sucrate, has never received any serious industrial application, because of the expense of the soda, and, above all, because the presence in too great quantity of-this reagent renders the filtration impossible. This process only finds its application in cases where the saccharine liquors operated upon contain a very small quantity of sugar.

It results, from what precedes, that the first system only gives good results when the liquors contain a very considerable quantity of sugar, while the second, on the contrary, is only useful when the liquid contains little sugar. Observing this, I have sought, by combining the two and somewhat modifying them, to profit by the ad vantages which they present and to do away with their inconveniences. I have thus inaugurated a new process of treating molasses, which is the subject of the present invention.

The process is divided into two operationsthe first comprising the formation of an insoluble sucrate, the second comprising the treatment of the mothcr-watersof this sncrate to extract the sugar thereii'rom.

First operalioa-jbrmat0u of an insoluble .s-ucralc.lhe molas; or the draiuings are brought in a stirring a maratus to a sugar strength of live to ten per cent. by means ofa cold milk ot'lime containing lime to the extent of lifty to eighty per cent. of the weight of the sugar contained in the solution. This quantity of lime will be insufficient to produce a complete reaction; but it presents the advantage of commencing it without sudden elevation of temperature-a condition essential to a large formation of bibasic sncra-te, which only, as is known, is that which is most completely decomposed by'hcat into'tribasic sucrate and sugar. Vhen the mixture is quite ICC homogeneous and this reaction takes place, I

make an addition of quicklime reduced to a which it contains, and I convey it to a boiler to be submitted to the action of heat. In pro portion as the temperature rises up to the temperature of eentigrade the liquid becomes thick by reason of the formation of tribasic sucrate, which takes place cimpletely when it arrives at the point of ebullition after the formula 3(O12H11 11 0) :9 (C12 n n 0) C H O This point being attained, the excess of lime which I had eliminated to facilitate the transformation of soluble sucrate into insoluble sucrate is added little by little to the liquid,which is always maintained at the point of ebullition. The return to the work of this excess of lime" presents two important advantages: it prevents the loss of sugar and renders the sucrate in abetter condition for washing, giving it by the presence of an excess of lime more porosity, and consequently more permeability.

It is known that thetribasic sucrate of lime is a gelatinous body, and consequently difficult of filtration. The presence of an excess of lime causes the disappearance of this grave defect. Thus in my system the lime is taken away when its presence is hurtful, and, on the contrary, replaced in the liquid when its presence has become necessary.

When the mixture is effected, I separate the insoluble sucrate from its mother-waters by sending it,at the temperature above indicated, to the washing filter-press, either by means of pumps or by means of a monte-jus. The sucrate remains in the apparatus in the form of cakes, which I wash with boiling water, the

mother-waters flowing away to be submitted to the second operation. The sucrate thus formed is collected and placed in a stirring apparatus,where I make of it a milk of a dilution which renders it suitable either for the liming of juices or sirups.

Second operationthe treatment of the motherwaters.The mother-waters collected in the preceding operation containing yet about three per cent. of sugar, the preceding process cannot further be applied with success without restoring these mother-waters to their primitive sugar strength by the addition of a new quantity of molasses. Now I have found, in doing this, inconveniences which have led me to reject it. I prefer to employ the following process: The mother-waters pass from the filter-press into any suitable refrigerator, to be brought to a normal temperature, or are sent, if circumstances permit, directly into a tank, where they are allowed to cool. \Vhen waters have extracted from them by filtration, for the same reason,their excess of lime. Then they are sent into a boiler, which may be furnished with a stirring apparatus.

It is to be remarked here that in view of the small proportion of sugar the addition of quicklime, even in excess, does. not sufficiently raise the temperature to form n1onobasic sucrate. I shall have then almost exclusively bibasic sucrate; but as by the action of heat this bibasic sucrate is converted into tribasic sucrate and into sugar, which would be lost or would necessitate an ulterior operation, I add, in the boiler, a solution of chloride of lime in sufifieient quantity to form an insoluble sucrate of lime; I mix intimately; I

heat; then I add a quantity of caustic soda in proportion equivalent to that of the chloride of lime to be decomposed. As soon as this addition is made, cold or hot,the reaction takes place. Under the action of heat the bibasic sucrate of lime is decomposed, as is known, into tribasic sucrate and into sugar; but on the other hand the lime set at liberty by the substitution of the sodium of the soda for the lime of the chloride of lime is found in a nascent state, which facilitates its combination with the sugar already set at liberty, and, finally, all the sugar is obtained in a state of tribasic sucrate.

As I have said, the operation may be made cold; but it is preferable to use heat, whic facilitates the preceding combination, and, moreover, facilitates the ulterior filtration.

WVhen a temperature for the separation of the sucrate is attained, I send the liquid to the filter-press, in which it is formed into cakes, which are washed and collected, to be employed as hereinabove stated in describing the first operation.

The excess of lime which had been previously eliminated may be added to that of the first operation, or replaced, if desired, in the mother-waters, after precipitation of the sucrate.

The mother-waters may afterward be treated to extract from them the saline azotized and organic matters,or be directly utilized for fertilizers.

It will easily be understood that in the sec ond operation, which I have just described, I may substitute for the chloride of lime any salt of lime whatever; also, that I may replace the soda by any alkaline or alkaline earthy base whatever without departing from the principles on which my invention is based.

Even though the two operations described IIO may suffiee to completely exhaust the saccharine liquors, I reserve to myself the right to repeat them, if necessary.

lVhat I claim as my invention, and desire to secure by Letters Patent, is

1. The improvement in the art of extracting sugar from saccharine liquid,consisting in adding to the liquid more than sufficient milk of lime and quicklime in powder to produce a soluble suerate of lime, filtering the solution to remove the excess of lime, heatingthe filtered solution to about 100 eentigrade, re turning to the solution the lime previously removed by filtration, refiltering to separate the tribasic sucrate of lime from the motherwaters, then adding quicklime to the resulting mother-waters, filtering the mixture to es:- tract the excess of lime, adding to the filtered liquid, first, asaltof lime in sufficient quantity to form t-ribasic sucrate of lime, and afterward an alkaline or alkaline earthy base to transform the remaining sugar into tribasic sucrate of lime, and, finally, filtering the liquor from the sucrate, all substantially as herein described.

2. In the process of converting the sugar of saccharine solutions into sucrate of lime by first adding lime to produce a bibasic sucrate' O. CREMER, Rom. M. Hoornn.