SK36698A3 - Continuous process for producing tartaric acid and fodder yeast - Google Patents

Abstract

The disclosure pertains to a continuous process for the simultaneous treatment of wine sediments to produce tartaric acid and fodder yeast with the aid of cationic exchange resins. The process involves passing an aqueous suspension made from a natural untreated wine sediment through a column containing a fluidised or quasi-fluidised cation exchanger and extracting the tartaric acid and fodder yeast from the suspension thus obtained.

Description

Technical field

The present invention provides a process for the continuous preparation of tartaric acid and yeast feed.

More precisely, the present invention provides a continuous process for preparing tartaric acid and yeast feed from yeast sludge from wine.

More precisely, the present invention relates to a continuous process for preparing tartaric acid and yeast feed from yeast sludge from wine using a fluidized or quasifluidized cation exchange resin.

Yeast sludge is a by-product of wine making, which contains yeast and tartaric acid salts, poorly soluble in water, mostly potassium, sodium and calcium salts, which, after the fermentation process, separate from the young wine and settle at the bottom of the barrel or tank. For the purposes of the present invention, these yeast sludges are considered to be both pressed and unpressed deposits.

The easiest way to prepare tartaric acid from the by-products of wine production is to dissolve poorly water-soluble tartaric acid salts by adding acid or alkali, separating the solids by filtration and precipitating tartrate ions in the form of calcium salts. The calcium tartrate is hydrolyzed with sulfuric acid and the tartaric acid is isolated by crystallization. Protein yeast is damaged by acid or alkali and cannot be isolated in a usable form. The disadvantage of this method is the large amount of environmentally harmful waste, which is also difficult to process.

BACKGROUND OF THE INVENTION

The method described in French patent application no. FR 1,422.108 uses crude tartaric acid (containing at least 50-55% tartaric acid), which is heated to approximately 170 ° C and milled to a particle size of 0.1 mm. From this material, a solution containing only 10% tartrate can be prepared by direct ion exchange, from which tartaric acid is crystallized. The process is not continuous, a considerable amount of energy is consumed for heating, as well as for grinding to a particle size of 0.1 mm and to thicken the dilute tartaric acid solution. However, the concentration of impurities increases.

In the method as described in Hungarian patent application HU 160.171, potassium and sodium hydrogen tartrate are dissolved in water and a strong cation exchange resin is used to release the tartaric acid. Because the potassium and sodium hydrogartartates are only slightly soluble in water, the solubility increases by a higher temperature at the solution passing through the column, thereby increasing the amount of tartaric acid in the effluent. The elevated temperature used in this process results in higher energy consumption, a higher temperature damages the proteins in the yeast, and tartaric acid is obtained in a small yield.

Using the method as described in Hungarian patent HU 157.933, the compressed yeast sludge is dried, finely ground, the fats contained therein are extracted with organic solvents, the solvents are evaporated and the tartaric acid is isolated by acidification of the residue. However, the use of organic solvents contaminates the processed material and, after evaporation of the solvents, heat destroys the yeast proteins.

All known processes have the common drawbacks that the wine yeast sludge is not treated comprehensively so that both tartaric acid and protein-rich yeast can be obtained in satisfactory yields, and in most cases the dry yeast material becomes an environmentally harmful waste.

The disadvantages of the methods that represent the state of the art are due to procedural difficulties that have not been solved comprehensively. Tartrates are only slightly soluble in water and the release of highly soluble tartaric acid due to acids or bases causes damage to yeast proteins, while using an ion exchange resin to release tartaric acid requires a very dilute solution, since the aqueous suspension of yeast sludge cannot pass through the column. ion exchange resin, because it would clog it.

Our goal was to develop a method overcoming the above difficulties, to find a method that would not have the disadvantages of known methods. At the same time, our aim was to develop a process requiring only a minimum amount of energy and chemicals, while providing high quality tartaric acid and yeast suitable for use as animal feed, while producing only a minimum amount of environmentally harmful waste.

SUMMARY OF THE INVENTION

The present invention is based on the notion that an aqueous solution of wine yeast sludge passing through a column packed with a fluidized or quasifluidized cation exchange resin provides a tartaric acid suspension containing yeast. The yeast-containing tartaric acid solution thus prepared in suspension allows the tartaric acid to be separated from the yeast without damaging the yeast. Fluidization of the cation exchange resin in the column prevents it from clogging and thus allows continuous operation.

Fluidization is a method known to those skilled in the art in which the fluid medium flows at a rate higher than the sedimentation rate of the solid particles contained in the fluid, called the fluidization threshold rate, and thereby keeps the solid particles floating. Quasifluidization is also a method known to those skilled in the art in which the flow rate periodically fluctuates between two speeds, somewhat higher and the other lower than the aforementioned sedimentation rate, thereby keeping the solid particles floating.

The value of the fluidization threshold of the fluidized medium in all cases depends inter alia on the density and viscosity of the fluidized medium, in this case the yeast sludge slurry from the wine and the density of the solid phase, in this ion exchange resin method. Above the fluidization threshold there is an interval at which a suitable flow rate can be selected. In all cases, this interval should be determined experimentally and depends on the geometry of the column and the amount of resin in the column among other factors.

The present invention provides a continuous process for producing tartaric acid and yeast from yeast sludge from wine using cation exchange resin, characterized by:

A. passing the yeast sludge suspension from the wine through a column packed with a cation exchange resin at a rate that ensures that the ion exchange resin remains in the fluidized bed, the resulting yeast suspension in aqueous tartaric acid is placed in a tank from which parts of the suspension can be recycled bottom of column, or

B. passing an aqueous suspension of yeast sludge from wine through a column packed with cation exchange resin in which a pulsating flow periodically fluctuates between a rate above and below the threshold fluidization rate ensuring that the ion exchange resin remains in the quasifluidic layer, the resulting yeast acid suspension in the aqueous solution is introduced into a tank from which, if necessary, the suspension parts can be recycled to the bottom of the column and the suspension is centrifuged and / or passed through a column packed with anion exchange resin, evaporated, crystallized and precipitated as calcium tartrate if necessary, providing tartaric acid and solids containing yeast.

By using a column packed with cation exchange resin in a fluidized or quasi-fluoridized state, it is possible to avoid blockage of the column when passing the solid phase containing the wine fermentation sludge.

The fluidization rate of the ion exchange resin with an aqueous suspension of wine yeast sludge is usually between 1.4.10 ^-3 to 8.10 ³ m ^{3 /} sec ^/ m ² .

The cation exchange resin, which transforms the potassium, sodium and calcium salts of tartaric acid into the free acid, is regenerated by conventional methods, wherein the regeneration time is determined from the pH of the effluent and the continuous operation allows the feed to be alternately fed to the two tandem columns.

The tartaric and yeast suspension fed to the auxiliary tank is processed continuously. Processing can be carried out as follows:

- the suspension is introduced into a centrifuge (or any other device for separating the solid and liquid phases from the mixture, such as a filter press) and the liquid leaving the centrifuge is either concentrated and the tartaric acid crystallizes, or is introduced into a column packed with anion exchange resin. After saturation of the column, tartaric acid is eluted with strong acid, and tartaric acid is crystallized from this relatively concentrated solution. (The anion exchange may also be continuous by using two or three columns packed with anion exchange resin, and this rotation is controlled by the pH of the fluid leaving the column.) The solid phase may be dried, if necessary, by conventional procedures in admixture with known additives and used as feed yeast. or

- the suspension is fed to a column packed with a fluidized or quasifluidized anion exchange resin, wherein the tartaric acid-free suspension leaving the column can be filtered and treated as described above for solid phase separation, and the tartaric acid can also be separated as described above. ).

The method described in this patent application allows the separation of all tartaric acid contained from the tartaric yeast sludge, so that the undamaged tartaric acid-free mass of yeast can be used as feed yeast. The energy requirements of this process are very low and no environmentally harmful products are produced.

DETAILED DESCRIPTION OF THE INVENTION

The examples below describe this method in more detail, without limiting the claims of this patent application:

EXAMPLE 1

250 kg of compressed yeast sludge (water content 48%, tartrate content 19%) are suspended in 2500 l of deionized water in the mixing tank. The slurry is fed to the bottom of the column (500 mm diameter, 4000 mm height) packed with 355 L of Varion ® KSM thick cation exchange resin at a rate of 3.3 x 10 ³ m ^{3 /} sec.m ² required to hold the ion exchange resin in the fluidized bed. The pH of the slurry exiting the column was measured and when the pH reached 3.2, the feed was transferred to another column and the previously operated column was recovered. The suspension exiting the column was fed into the container. Next, the suspension was fed from the reservoir to a centrifuge where the solid and liquid phases were separated, the liquid phase was concentrated and the tartaric acid was crystallized. 32 kg of pure tartaric acid (yield 67%) and 97 kg of solid phase (81%) containing yeast were isolated.

EXAMPLE 2

The process is identical to that described in Example 1 except that the liquid phase from the centrifuge is fed to a column packed with Varion® anion exchange resin until saturation and after elution from the column with mineral acid, tartaric acid is allowed to crystallize (37.8 kg, 80% yield).

EXAMPLE 3

The method is identical to that described in Example 1 except that the slurry is fed from the container to a column packed with fluidized anion exchange resin, Varion® anion exchange resin, and when the pH of the slurry leaving stream reaches 3.2, its flow is transferred on a new column. From the solution leaving the column, the filter press is filtered to obtain a solid phase with a yield of 109 kg (91%) of the solid phase containing yeast. The tartaric acid bound to the column is eluted with a mineral acid and is crystallized from the resulting solution in a yield of 31.5 kg, i. 67%.

EXAMPLE 4

The method is identical to that described in Example 1 except that the slurry is loaded onto the column according to the following flow program:

3.3.10 * ³ m ³ /sec.m ² for 30 seconds, followed by

2,3.10 ^{"3 m3} /sec.m ² for 10 seconds, the valve on the supply of raw material is periodically alternate columns. The resulting amount of tartaric acid was 39 kg (82%).

Claims (8)

PATENT CLAIMS A continuous process for preparing tartaric acid and feed yeast for animal production from wine yeast sludge using a cation exchange resin column, characterized in that: A. aqueous slurry of wine yeast sludge rises through a column packed with cation exchange resin at a rate that ensures that the ion exchange resin is maintained in a fluidized state, the tartaric acid and the yeast-containing slurry is discharged from the column to a container from which a fraction can be recirculated bottom of column, or B. aqueous slurry of wine yeast sludge rises through a column packed with cation exchange resin at an average rate that fluctuates around the rate needed to keep the ion exchange resin in a quasi-fluoridized state, which is achieved by periodically alternating lower and higher speeds than the rate required to maintain the resin in fluidization state, wherein the tartaric and yeast suspension leaving the column is fed to a container from which part of the suspension may be recycled to the bottom of the column as necessary and the suspension is centrifuged and / or passed through an anion exchange resin column, evaporated, crystallized, precipitated as calcium tartrate and the resulting product is tartaric acid and a yeast-containing solid phase. Method according to claim 1, characterized in that the aqueous suspension of wine yeast sludge passes through a column filled with cation exchange resin at a rate of 2.8 x 10 ^-3 to 5.6 x 10 ^-3 m ^{3 /} sec.m ² . The method of claim 1, wherein the aqueous yeast sludge suspension is passed through a column packed with cation exchange resin at a rate that periodically alternates according to a flow rate program: at least 10 seconds 1 to 20% above and 5 to 30 seconds 1 to 20% below the threshold fluidization rate. 7> l / Method according to claim 3, characterized in that the periodic changes in the flow rate of the feedstock are carried out by periodically injecting the recirculated feedstock in the form of a suspension from a container containing a suspension that has already passed through a column packed with an ion exchange resin. Process according to any one of claims 1 to 4, characterized in that the suspension from the container is fed into a centrifuge, the solid phase is dried and, after addition of commonly known additives, is processed into animal feed containing yeast. Method according to claim 5, characterized in that the solution leaving the centrifuge is concentrated and the tartaric acid is isolated by crystallization. Method according to claim 5, characterized in that the solution leaving the centrifuge is fed to a column packed with anion exchange resin and the tartaric acid bound in the column is finally eluted with a mineral acid stronger than tartaric acid, whereupon tartaric acid is isolated from the solution by crystallization. Method according to any one of claims 1 to 4, characterized in that the suspension from the container is fed to a column filled with a fluidized or quasi-difluidized anion exchange resin.