DE2641595A1 - IMPROVED CHEMICAL PROCESS FOR THE RECOVERY OF PURE CARBON HYDRATE SOLUTIONS (LIQUID SUGARS) FROM IMPURE AND MOISTURE SUGAR-CONTAINING SOLUTIONS - Google Patents

Description

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September 15th

REGGIANE Officine Meccaniche Italiane S. p. A.

Milano (Italy)

IMPROVED CHEMICAL PROCESS FOR THE RECOVERY OF PURE CARBON HYDRATE SOLUTIONS (LIQUID SUGARS) FROM IMPURE AND Cloudy SUGAR SOLUTIONS

The present invention relates to an improved chemical process for the production of pure carbohydrate solutions (Liquid Sugars) made from impure and cloudy solutions containing sugar.

This process is suitable for the treatment of impure and also cloudy solutions with a high percentage in carbohydrates, such as those obtained in sugar factories Juices and syrups based on sugar beet or sugar cane, sugar millet extracts, in the utilization of Corn, potatoes, yuca and tapioca fragile glucose and / or fructose solutions in the recycling of waste

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Pineapple, dates, dried figs, prickly pears, Jus d ¹ arable resulting solutions, etc. Often such solutions are, despite the high percentage content of carbohydrates not practical exploited for lack of economically favorable chemical processes that can be used which ein.genügend pure end product obtained.

For the clarification of sugary solutions, the following two methods have essentially been used:

a) chemical clarification using chemical reagents such as iron hydrates, aluminum hydrates, lime, Phosphoric acid, carbonic acid, etc.

b) Clarification with the aid of ion-exchangeable resins. The two methods are often used in addition to one another.

The clarification of sugary solutions with the help of chemical reagents has two disadvantages, Firstly, the high cost of the reactants and, secondly, the low degree of purity of the end product.

In conventional systems in which sugary solutions are clarified with the help of ion-exchangeable resins are, resins come to. Use, their chemical-physical Properties to be chosen according to the impurities to be removed:

a) ion-exchangeable resins in the proper sense, which

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exchange its own ions with the ions present in the solution in question. If a solution comes up first
a cationic resin charged with H ions and then treated on an anionic resin charged with OH ions, this solution gives off a large part of its cations and anions to the resins and replaces them with them
the ions present in the resins.

b) Resins, which with the exclusion of certain ions
and molecules work. The ions and molecules, which are larger than the pores in the resin, are prevented from reacting with the resin.

c) Resins, the effect of which is based on the retardation of ions, whereby certain ions are hindered in their passage through the resin and delayed in time with respect to other ions. This phenomenon is related to the presence of polar groups in the resins which the
Cause delay of macromolecules with opposite polarity.

d) Resins, which because of their particular porosity, have molecules adsorb.

These resins are used individually and can therefore
Exercise a single clarifying function tailored to their chemical-physical properties.

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The resins used in these individually based processes thus have the great disadvantage of a restricted certain impurities clarification to _f while all others remain in the sugar-containing solution. '

If you want to achieve a better clarification, you are extremely relied on expensive large systems, which are not very efficient from a technical point of view and are high Bring acquisition and operating costs with them.

In the course of technical progress, there has recently been a chemical process for the extraction of pure Realized carbohydrate solutions from impure sugary solutions, in which four resins are used, whose chemical-physical properties are chosen so that at the same time an actual ion exchange, a Ion delay, ion and molecule exclusion, and adsorption take place.

Although this process due to the great advantages in the Has achieved remarkable success compared to the previously used methods, difficulties have arisen which are mainly related to the fact that this process only deals with particularly clear solutions which considerably limits the scope of application.

The most important aim of the present invention is therefore that

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Provision of a process with which any also cloud and sugary solution containing substances in the colloidal state a pure carbohydrate solution can be won.

These and other goals are achieved by the invention improved chemical process for the extraction of pure carbohydrate solutions (L.S.) from impure and cloudy sugary solutions, which essentially consists of the following basic operations.

Further characteristics and advantages of the inventive chemical cleaning process will be more clearly apparent from the detailed description of a preferred embodiment, which is shown, for example, in the attached drawing using a basic diagram.

With 1, the collecting container is the one from previous processing processes accruing cloudy, sugar-containing solution, which acts as a reservoir for the whole plant is used.

The sugar-containing solution is pumped from the collecting container 1 to a centrifuge 2. This is preferably a drum centrifuge, or it can be a continuous decanter centrifuge such as for milk, · .-., Fruit juices, etc. can be used. In this centrifuge, the sugary solution undergoes a mechanical clarification

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subjected, whereby the existing solids can be excreted down to 1 g / l.

The thus clarified solution is pumped into an ion exchange column 3, which (referred to in the following description with C) to "70% with resin with a strong cationic activity, and to 30% with, other resin nn.t strong cationic activity (with MB The strong cation exchanger C has functional groups of -SO H / and a fine or coarse, porous, cross-linked structure. Commercially available resins can be used for this purpose, such as Amberlite IR-122 from Rohm and Haas, for example Co., Fort C 300 by Montedison and the like.

Resin C has a remarkable exclusion effect, by letting all large-volume ions and molecules pass through and thereby preventing a reaction with the resin. In addition, an intensive ion exchange takes place in resin C, and a large part of the in cations present in the sugary solution are exchanged with H ions, provided that these are not be affected by the above-mentioned exclusion due to their size.

The strong cation exchanger MB has functional groups from -SO H and a coarse-pored cross-linked structure. The porosity must be at least 30%, and the pore size

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diameter must not be smaller than 250 A. To this Commercially available resins such as Amberlite IR-200, Relite CFZ and the like can be used for this purpose.

The resin MB completes the ion exchange on the large-volume cations, which from the reaction with the Resin C are excluded.

It also causes a significant delay by it accelerates the movement of carbohydrates and large molecular weight and non-ionic molecules with the resin of opposite polarity delayed. After all, this resin has a decolorizing effect.

After the sugar-containing solution has passed through the ion exchange column 3, it becomes a further ion exchange column 4, which 90% with an anionic resin (referred to as A in the following description) and is filled to 10% with another type of anionic resin i (denoted by AG).

When anionic resin A is a large pore crosslinked polyamine backbone having _£ whose porosity at least 35% must be, the Pprendurchmesser to be not less than 250 A.

Commercially available resins can be used for this purpose, such as Amberlite IRA-93 _r Relite 4MS from Re-

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sintion and the like.

When the solution passes through the anionic resin A, an intensive ion exchange takes place, namely, the OH ions present in the resin are exchanged with about 90% of the aniones present in the sugar-containing solution. Thanks to its large-pored nature, this resin also causes strong physical adsorption.

The resin AG is a jelly-like resin with a large-pored structure, the pore diameter of which is less than 10 Å on average such as Amberlite IR 45. This resin has the task of promoting the elimination of the anions present in the sugary solution.

The substances present in the sugar-containing solution in a colloidal state, especially the reversible ones Colloids, that is, those substances which change from the "sol" state to soft, slightly elastic, under the name "Gel" solidify known masses and then convert them back into "Sol" by adding the dispersing agent can reach their isoelectric point, since most of the ions are removed from the sugary solution been isC. This creates an opalescent solution, which needs clarification. .

For this purpose, the solution is passed into a clarification vessel 5 and subjected to a chemical clarification therein.

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This chemical clarification can be achieved by a number of conventional methods, including the Addition of aluminum or iron salts, lime, bentonite, gelatine, etc.

However, it is preferred to add compounds such as phosphotic acid or phosphates to the solution, which can release _{phosphorus pentoxide in the order of magnitude of 50-500 ppm P 9 O;} it is then neutralized with lime (Ca (OH)) until a pH of 7 to 8.5 is achieved. A pH meter 6 is provided to measure this value. The reaction between phosphorus pentoxide and lime creates large flakes of tribasic calcium phosphate, which incorporate the substances in a colloidal state and thereby facilitate their removal.

The solution is then heated in a heater 7 up to a temperature of 80-105 C in order to start the coagulation process to favor. An organic flocculant is also added to make decanting easier. which takes place in a special decanter 8.

The sugar-containing solution is then filtered through a filter 9 made of tissue and bone meal.

The sugar-containing solution clarified in this way is brought to the desired temperature in a cooling device 10 and pumped into an ion exchange column 11.

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This column is about 95% with cationic resins MB and about 5% with an adsorbent resin (in the following Description marked with X) filled.

The cationic resin MB should possibly remain in the "solution Eliminate cations.

The adsorber X consists of a porous resin with a coarse network structure, the porosity of which is 40-45%, and whose pores have a diameter of 85-95 Å. For this purpose, resins such as Amberlite X .AD 2 from Rohm and Haas Company and the like can be used.

The adsorber X has "the task of removing the organic substances, in particular to adsorb phenols and sulfone compounds, which have undesirable effects on the end product would have.

The sugary solution is in the adsorption column 12 subjected to further clarification.

This adsorption column is about 95% with medium strength and strong anionic resin (denoted by D in the following description) and about 5% with an adsorber (denoted by Y in the following description) filled. Resin D has polyamine or quaternary ammonium groups and a porous, coarse-meshed framework; its porosity is at least 45% and the pore diameter is

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not smaller than 500 Ä. For this purpose, commercially available resins such as Amberlite IRA 68, IRA 900, Lewatit MP or MP4 500 from Bayer and the like can be used.

Resin D exchanges the remaining 10% of that left over by Resin A. Anions and delays the large non-ionic molecules present in the solution. These macromolecules are partially retained by the porous framework of the resin D.

The resin D also has a great adsorption effect, which can be observed in the intense discoloration of the solution.

The adsorption is further enhanced by the presence of the adsorber Y in the column.

Adsorber Y is based on a resin of acrylic ester with a porous, coarse-meshed framework with an average pore diameter of 90 Å, which is mainly polypeptides and proteins adsorbed.

The sugary flowing from the ion exchange column 12 Solution is completely clarified and is passed into an evaporator 13 for the final concentration. This Evaporator works under vacuum at a temperature of about 50 C. Depending on the capacity of the system, it can the solution by one, two or more stage evaporation

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be concentrated.

The sugar-containing solution clarified and concentrated in this way is discharged into a storage container 14.

The amount of resin used for each workflow obviously depends on the amount and nature of the process any impurities present in the solution to be clarified. For every 100 grams of impurities in the solution the following guide quantities are required:

- 280 to 420 ecm resin C

- 330 to 420 ecm resin A

- 75 to 115 ecm resin MB

- 65 to 95 ecm resin D "

- 4 to 6 cm resin X

- 3 to 5 ecm resin Y.

The used resins must of course be washed, sorted and reprocessed with suitable chemical reagents will. . . .

For the cationic resins C and MB, it is preferred to use Mineral acids such as sulfuric acid or hydrochloric acid in about 2N solution and in the order of about 3-4 gr per liter of resin.

Resins A and D, which act as anion exchangers, are prepared with the aid of a base, preferably

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with baking soda in 1N solution, in the amount of 2-3 gr per liter of resin. After removing the processing reagent with water the resins can be used for a further clarification process be used.

When carrying out the chemical process according to the invention should occur during percolation in the ion exchange columns preferably the following conditions prevail:

- Temperature between 1 and 70 C

- Pressure between 0.2 and 10 atü (optimum 1-2. Atü)

- Concentration of the solution to be clarified between 5% and 60% (optimum 3O-4O%)

- Throughput between 0.2 and 10 volume of solution per volume of resin (optimum 1-2 volume / volume C / h).

It has been observed that the change in working conditions leads to quantitative changes in the percentage of carbohydrates in the finished solution.

Especially when using low temperatures (1-15 C) and with short contact times (max. 20 minutes) the same carbohydrates are found in the pure, finished solution as are present in the 'initially impure' solution were in the same proportions. Steep

If the temperature is gradually increased from 15 to 70 C and the contact times from 10 to 150 minutes the pure finished solution has a greater percentage of monosaccharides than the impure starting solution; this as a result

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ge that occurred when the solution came into contact with the resins Hydrolysis.

The method according to the invention has the following advantages compared to the methods used hitherto: 1. Any desired, even cloudy, sugar-containing solution can be treated.
2. An extremely intensive clarification is achieved; the draining solution is purer, almost completely colorless and contains absolutely no minerals. '

3. The procedure is very simple and can be carried out with equipment of modest dimensions.

4. No muddy and colloidal substances are removed, which are often harmful and difficult to remove.

5. The consumption of chemical reagents and thermal and electrical energy is low.

The invention so designed can be evident numerous changes are made; for example, the system of mechanical clarification, the chemical Clarification, filtration, etc. with other technically equivalent Methods' are replaced which do not exceed the scope of the invention.

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Claims (5)

P a t en t to s ρ rü ch e 1. Improved chemical process for the extraction of pure carbohydrate solutions (liquid sugars) from impure and cloudy solutions containing sugar, characterized by those following one another in the order described Basic operations: - mechanical clarification of the cloudy, sugary solution using a drum centrifuge or an equivalent Contraption, - Percolation of the clarified sugary solution through an ion exchange column, which is 70% with a being strong Cation-exchanger acting resin C with functional groups from -SO H and a fine or coarse network structure, and 30% is filled with a resin MB acting as a strong cation exchanger with a coarse-pored crosslinked structure, the Porosity is at least 3O%, and its pore diameter is not less than 250 A, - percolation of the sugary solution through an ion exchange column, 90% of which with a resin A with polyamine groups acting as a weak or medium cation exchanger and porous ,. coarsely cross-linked framework. is filled, whose porosity is at least 35%, and whose pores have a diameter below 250 Å, while the rest 10% with a gel-like anion exchanger Harz AG are filled with a fine-pore structure whose "mean pore diameter is less than 10 A, - chemical clarification of the sugary solution, 15th 7098U / 0674 - Filtration and subsequent cooling of the sugary Solution, - percolation of the sugary solution through an ion exchange column, which approx. 95% with the resin MB, which acts as a strong cation exchanger, and approx. 5% with an adsorbent resin X is filled with a porous, coarsely cross-linked framework, the porosity of which is at least 40-45%, and its pore diameter not smaller than 85-95 £ is - Percolation of the sugary solution through an ion exchange column, 95% of which with a resin D acting as a medium or strong anion exchanger with polyamine or quaternary ammonium groups and porous, coarsely crosslinked framework is filled, the porosity of which is at least 45%, and its pore diameter is not smaller than 500 Å, while the remaining 15% with an adsorber Y are filled, which consists of a resin based on acrylic ester with a porous, coarsely crosslinked framework with a mean pore diameter of 90 A, - Final concentration of the sugary solution. 2. Process according to claim 1, characterized in that this chemical clarification of the sugar-containing solution on the following Way goes on: - adding a phosphate compound to the sugary solution for the release, of phosphorus pentoxide, - Neutralization with lime until a pH value of 7 to 8.5 is achieved, 709814/0674 - heating the sugar-containing solution to a temperature of 80-105 ⁰ C, - Decanting by adding an organic flocculant 3. Process according to claim 1, characterized in that the percolation in the ion exchange columns at one temperature between 1 and 15 C and with short contact times (max. 20 minutes) is carried out in the pure finished solution to achieve the same percentage of carbohydrates as in the impure starting solution. 4. Process according to claim 1, characterized in that the percolation in the ion exchange columns at a temperature between 15 and 70 C and contact times of 15 to 150 minutes is carried out to finish in the pure Solution a larger percentage of monosaccharides than to be achieved in the impure starting solution. 5. Process according to claim 1, characterized in that the percolation in the ion exchange columns at a Pressure between 0.2 and 10 atmospheres (optimum 1-2 atmospheres), with one Concentration of the solution to be clarified between 5% and 60% (optimum 30-40%) and with a throughput between 0.2 and 10 volume of solution per volume of resin C / h (optimum 1-2 volume of solution / volume of resin c / h) is carried out. ■ 7098H / 0674