Industrial purification of alcohol. Without extreme sports and hangover. Methods for home purification of vodka and alcohol

Potassium permanganate during the oxidation reaction forms manganese peroxide. It should be noted that when straightening raw materials using a chemical method, an excess of both caustic alkali and permanganate is harmful. An excess of alkali leads to the fact that the alkali, acting on alcohol, converts it into an aldehyde. Excess permanganate, after the oxidation of aldehydes and unsaturated compounds, also oxidizes alcohol. Therefore, of the numerous methods proposed for correcting alcohol, we cannot recommend those that give general recipes, without taking into account the characteristics of the raw material being corrected. In each individual case, the amount of required reagents should be calculated based on the analysis of the raw material. Of the correction methods based on a preliminary analysis of the composition of the raw material, we will focus on the method of A. N. Gratsianov.

According to the Gratianov method, the amount of alkali necessary for binding acids and saponifying esters is determined by preliminary determination. For this 100 ml raw milk is boiled with 10 ml decinormal alkali in a flask with reflux condenser In one hour. After cooling, add 10 ml decinormal H 2 SO 4 and the excess of the introduced acid is titrated with a decinormal NaOH solution using phenolphthalein as an indicator. The amount of alkali used for titration must be added for every 100 ml raw. The alkali solution is introduced in two doses. Initially, take only half the calculated amount in the form of a 10% NaOH solution, after 10 - 15 min After mixing with alkali, a 2% solution of permanganate is introduced into the raw material in such an amount as to oxidize only unsaturated compounds. The required quantity is determined by preliminary experiment. To do this, in a conical flask with a capacity of about 100 ml pour 1 ml KMnO 4 solution (0.2 G by 1 l water) and the test raw material is poured from a burette with constant shaking of the flask at a flow rate of about 20 - 30 ml/min until! the alcohol will not turn pinkish-yellow. The amount of alcohol used to deoxidize the samples taken is 0.0002 G KMnO 4 is the starting value for determining the amount of permanganate required to correct alcohol. After introducing the KMn0 4 solution, the raw material and reagents are mixed again, and then left alone for 6 hours . After this period, stirring is resumed and the remaining half of the alkali is added. In 5-10 min stirring is stopped and the raw material can be sent for rectification.

Below are data that allow us to judge the results of chemical correction of raw alcohol (according to Gratsianov).

When rectifying alcohol using the so-called unified method, raw alcohol is not subjected to preliminary purification with alkali and potassium permanganate. Chemical cleaning is carried out inside the column with alkali, which is continuously fed into the column.

The question of the use of chemical purification for the treatment of alcohol obtained from defective raw materials is of great interest. V.P. Gryaznov and G.V. Rzhechitskaya investigated the effect of potassium permanganate, sodium hydroxide and sodium acid sulfate on aldehydes contained in alcohol obtained from processing defective raw materials. Solutions of butyraldehyde, acrolein and acetaldehyde in pure ethyl alcohol were processed. The authors found that the reagents they used had no effect on acrolein. As for acetic and butyraldehydes, treatment of alcohol with alkali and acidic sodium sulfate gave positive results.

When processing defective starchy raw materials and molasses, alkali is sometimes added to the upper plate of the distillation column in order to improve the oxidation test.

As a rule, this increases the oxidation time, but always leads to deterioration organoleptic indicators rectified alcohol.

As P. S. Tsygankov and Yu. D. Sliva showed, the improvement in alcohol performance when introducing alkali into alcohol is only apparent. Alkali gives alcohol unpleasant bitterness. Increasing the oxidation time creates the appearance of improving the quality of the alcohol.

2. Purification of alcohol with active carbon

Activated carbons are those which, after special treatment, acquire a huge adsorption surface and whose pores, as a result of this treatment, are freed from resinous substances.

Activated carbons are universal absorbers for alcohol impurities. This property of activated carbons was established by N. D. Zelinsky when developing the problem of alcohol denaturation.

The use of adsorption methods for the purification of water-alcohol mixtures has been known for a long time. In state-owned wine warehouses in pre-revolutionary Russia, the method of purifying water-alcohol mixtures by filtration through a layer of birch or linden charcoal was widely used. Coal was loaded into columns up to 4000 high mm, which were connected into batteries of 4-7 pieces. In these columns, a water-alcohol solution with a strength of 40% vol. filtered sequentially through coal at a rate ensuring the duration of contact with coal for at least 24 hours.

Later, for the purification of water-alcohol mixtures at distilleries of the Union, on the recommendation of prof. A. N. Shustova uses activated carbon of the norit type, the surface of which is 80-100 times greater than the surface of ordinary charcoal.

Filtration of water-alcohol mixtures improves their tasting properties, which can be explained by various considerations.

It is believed that coal adsorbs some alcohol impurities, which give the alcohol an unpleasant taste and aroma. However, it has been noted that coal not only absorbs impurities, but also catalytically activates the oxidation process of both the alcohol itself and its impurities. In this case, the formation of organic acids occurs. When combined with alcohol, they form esters, such as ethyl acetate, isoamyl acetate and others.

For a long time it was believed that it was impossible to purify vodka with large amounts of activated carbon and that the contact of vodka with carbon should not last more than 30 min, which was explained by the high activity of norite coal compared to conventional coal.

The norm has been set! for purification of 40% vodka: 16 grams of coal per 1 gave vodka with contact duration 30 min.

V.F. Komarov investigated the issue of using activated carbon to purify water-alcohol solutions from impurities and came to the conclusion that large doses of activated carbon (several kilograms per 1 gave vodka) under conditions of continuous filtration through a layer of coal (dynamic method) improve the tasting qualities of vodka.

Based on this study, it was proposed to treat vodka with charcoal in filters filled with activated carbon with a layer 4 in height. m. In this case, the filters were connected in series, 2 or 3 each. Recommended filtration speed 3.5 m/h.

During filtration, selective adsorption of a number of impurities from a complex multicomponent mixture occurs. The intensity of adsorption depends on the type of coal. It was noticed that isoamyl alcohol is absorbed more intensively (26-40%) than acetaldehyde (10-16%). With increasing dosages of coal (to a certain limit), an increase in the oxidation test (Lang test) was noticed. An increase in the amount of aldehydes due to oxidation was not observed.

V.F. Komarov also developed a simple method for the regeneration of activated carbon by treating it with water steam (0.7 ati) and cold air .

Thus, these studies have shown that the use of activated carbon to purify water-alcohol mixtures from impurities is quite possible under conditions of continuous filtration through a high-height layer.

At the same time, it was proven that the tasting qualities of the filtered solution are improved, apparently due to the extraction from the solution of ingredients that give the alcohol a bad taste and smell.

V.F. Komarov notes the great importance of pre-cleaning the treated solution from mechanical impurities by filtering the solution before feeding it into a carbon filter through sand filters.

The described cleaning methods have not been used in distilleries until recently. However, there is information that they are becoming widespread in some foreign factories. So, in some factories in France they use activated carbon treatment of epurate. This technique is used to obtain a rectified product of particularly high purity. For this purpose, rectified alcohol is diluted with softened water to 30% vol. and plotted a second time. The hot epiurethane is passed through activated carbon of the Norit type. The purified epurate is subjected to strengthening in a distillation column.

It is believed that treatment of hot diluted epurate with norit helps remove impurities that are not captured analytically, but spoil the taste and aroma of the alcohol.

M. S. Shulman and A. N. Babkova studied the process of adsorption of ethyl alcohol impurities by activated carbon of the BAU brand. In laboratory experiments, they found that activated carbon extracts acetaldehyde from a 50% aqueous-alcohol solution at a concentration exceeding 0.0005% wt. At lower concentrations, an increase in the aldehyde content is noticed, as the authors believe, due to the oxidation of alcohol by impurities present in activated carbon. Activated carbon also adsorbs ethyl acetate and isoamyl alcohol from a 60% aqueous-alcohol solution.

The issue of using activated carbon for alcohol purification was also studied by G.L. Oshmyan and A.V. Ignatova in relation to the conditions of vodka production. The study involved sorting before and after treatment with an adsorbent. The authors of this work indicate that the organoleptic properties of alcohol depend on the qualitative composition of impurities, therefore, a change in the latter under the influence of treatment with activated carbon can change the organoleptic properties of alcohol.

Using a sensitive method of analytical determination developed by the authors, the authors discovered compounds of many organic acids (formic, acetic, propionic, etc.) in rectified alcohol. They found that under the influence of activated carbon, the qualitative composition of esters and acids shifts towards enrichment with compounds of large molecular weight. Apparently, the change should be associated with an increase in the tasting score after treatment with activated carbon.

Assessing the results of the ongoing research, we can assume that the use of activated carbons for purifying alcohol during the rectification process is promising and should be subjected to further research.

3. Treatment of alcohol with ion exchange resins

Synthetic ion exchange resins (ion exchangers) are solid high-molecular compounds, mechanically strong and insoluble in the treated environment.

In its structure, any ion exchanger consists of insoluble polyvalent ions that carry a positive or negative charge and are surrounded by mobile ions of the opposite sign.

If the charge of the polyvalent ion is negative, and the mobile ions are positive, then the ion exchanger is called a cation exchanger. Such an ion exchanger is capable of exchanging its mobile ions with external cations of the medium.

If the high-molecular frame of the ion exchanger carries a positive charge, and the mobile ions are negative, then such an ion exchanger is called an anion exchanger. It should be borne in mind that during ion exchange purification, molecular adsorption also takes place on the highly developed surface of the ion exchanger due to the action of molecular forces.

A well-synthesized ion exchanger should theoretically not dissolve in water and electrolyte solutions. In practice, however, at the beginning of the ion exchanger operation there is a more or less long period during which soluble substances that pollute the treated environment are leached from the ion exchanger.

Ion exchangers are manufactured in the form of a granular bulk mass or in the form of sheets of plates. Sheet ion exchangers are used as membranes for filtering the processed medium through them. To increase mechanical strength, membranes are reinforced with durable fabrics (fiberglass) or they are molded from a mixture of ion exchange resin and elastic plastic. Ion exchangers are widely used for water purification and softening. In the food industry they are used to purify sugar juices in the beet sugar industry, in the production of fruit waters to remove excess acid, etc.

There are indications of attempts to use ion exchangers to purify alcohol from impurities, but this method has not received widespread use.

V.P. Gryaznov and G.V. Rzhechitskaya, studying methods for processing defective starchy raw materials, used ion exchange resins to purify aqueous-alcohol solutions. The effectiveness of using ion exchange resins was studied on raw alcohol.

Of the resins they studied, the anion exchanger EDE-10P gave encouraging results. Experience in using this resin has shown that the amount of impurities in raw alcohol has decreased significantly. The authors found that the best cleaning effect is obtained for aqueous-alcoholic solutions with a strength of 40-50% vol., as can be seen from Fig. IX-1. An example of the use of ion exchange resins can be seen when cleaning a water-alcohol solution,

alcohol obtained from the processing of molasses, from impurities by treating it with ion exchange resins.

The authors of the studies suggested that the reduced tasting quality of alcohol produced from molasses is caused by the presence of intermediate impurities in the alcohol, primarily ethyl esters of propionic, butyric and valeric acids.

When alkali is introduced onto the upper plates of the distillation column to saponify them, salts of fatty acids are formed. These salts end up in the rectified product. When alcohol is diluted with water, they, according to the authors of the studies, give it a bitter taste and an unpleasant odor.

To remove the esters and fatty acids contained in alcohol, it is proposed to treat it using Ku-2 cation exchanger and EDE-10P and AN-F anion exchangers.

For the study, a semi-industrial installation was built at the Lvov Distillery.

The technological regime developed by the authors was as follows. The alcohol to be purified was sequentially filtered through a Ku-2 H-cation exchanger and then through an AN-2F or EDE-10P OH-anion exchanger. Alcohol filtration rate 3.0-3.5 gave/(kg-h). To ensure a regeneration cycle of 100 gave alcohol is loaded into ion exchange columns 55 kg anion exchanger and 40 kg cationolite. Dimensions of cylindrical columns: H = 1.5 m, d= 0.4 m.

For continuous purification of alcohol, two pairs of columns are installed. While one pair is working, the second is undergoing regeneration. Regeneration of ion exchangers is carried out by washing with water and passing regenerating solutions through a column. A NaOH solution is passed through the ion exchanger, and an HCl solution is passed through the cation exchanger. After passing through the regenerating solutions, the columns are washed with demineralized water.

The results of alcohol purification are given below.

In 1959-1960 laboratory experiments were carried out in which heat treatment samples of rectified alcohol of the first grade and highest purification that deviated from the standard for the oxidation test were subjected. These samples were overheated in an autoclave to 100-140° C for 5-20 minutes, after which part of the alcohol in the form of vapor was taken. When analyzing the cooled alcohol residue, a significant improvement in the oxidation test was found (by 10-15 min). Tasting characteristics have also improved. The optimal overheating temperature was found to be 100-110°C for a duration of 5-10 minutes.

Subsequently, the experiments were transferred to production conditions. Two production plants for the thermal treatment of alcohol were created: at the Michurinsky Experimental Plant and at the Lipetsk Distillery. The installation of the Michurinsky plant consisted of the following elements: an alcohol heater, a heater-holding unit, a refrigerator, a separator, an expander, an alcohol trap and a condenser.

In this installation, the alcohol coming from the 2nd and 3rd trays of the distillation column was kept at a temperature of 90-92 ° C for 5 minutes.

A similar installation at the Lipetsk plant made it possible to work at a higher temperature (98-99°C). It should be noted that in this case the temperature was significantly lower than that recommended by the French patent (130-140°C) and the optimal processing temperature found by laboratory experiments carried out at the Central Research Institute of Petroleum Processing (100-110°C).

It can be concluded that the reasons for the change in the quality of alcohol during heat treatment at the Michurinskaya installation could be: a change in the composition of alcohol impurities and the distillation of some highly volatile products and their removal from the condenser.

It is possible that the second reason in some cases is the main one.

Table IX-1 shows the alcohol analysis data before and after heat treatment at the Lipetsk plant.

Considering the data in Table. IX-1, we can state an improvement in analytical indicators. They also indicate an improvement in tasting characteristics. By comparing the analytical parameters of alcohols before and after heat treatment and condensate from the separator, it can be established that the distillation of highly volatile impurities plays a significant role in this process. However, it is not possible to determine the proportion of this participation, since the balance of impurities in the work is not given. The role of chemical processes occurring in alcohol during heat treatment is also very likely.

Whatever causes the improvement in performance, the possibility of improving the quality of alcohol through heat treatment should be recognized.

It is also interesting to monitor the behavior of individual alcohol impurities during heat treatment. In the work under review, the authors carried out gas chromatographic analysis, the results of which are given in table. IX-2.

Experiments carried out at more high temperature at the Lipetsk plant (98-99°C), basically gave the same indicators as the experiments at the Michurinsky plant.

Also of great interest are the studies of the heat treatment process carried out by Yu. D. Sliva and P. S. Tsygankov at KTIPP. In these studies, the chemistry of the heat treatment process was examined in more depth. (See also Yu. D. Sliva, P. S. Tsygankov, V. F. Sukhodol. “News of universities. Food technology”, No. 1, 1968.

LITERATURE

1. Gladilin N.I. Guide to alcohol rectification. Pishchepromnzdat, 1952.

2. Klimovsky D. N., Stabnikov V. N. Alcohol technology. Ed. 3rd. Pishchepromizdat, 1960.

3. Fertman G.I., Pokrovsky A.L., Vishnevskaya T.L. “Alcohol and vodka industry”, 1940, No. 3.

4. Gryaznov V.P., Rzhechitskaya G.V. Proceedings of TsNIISP. Vol. VIII 1959.

5. Tsygankov P. S., Sliva Yu. D. Sb. “Food Industry”, No. 6. Publishing House “Tekhnika”, Kyiv, 1967.

6. Serpionov A. N. Industrial adsorption of gases and vapors. State Chemical Publishing House, 1956.

7. Komarov V.F. Dynamic method of purification of water-alcohol solutions with activated carbon and regeneration of waste carbon in filters with steam and air. Abstract of the dissertation. VKhTI, 1949.

8. Ternovsky N.S., Gryaznov V.P. “Alcohol Industry”, 1960. No. 4.

9. Shulman M.S., Babkova A.N. Proceedings of TsNIISP. Vol. IX, 1960.

10. Oshmyan G. L., Ignatova A. V. Proceedings of TsNIISP. Vol. XI, 1961.

1 1

12. Danilko G.V., Korobenkova A.I. Proceedings of UkrNIISP. Vol. VII, 1960.

13. Danilko G.V. Purification of ethyl alcohol with ion-exchange resins. Abstracts of dissertations. KTIPP, 1965.

14. Danilko G. V., Egorov A. S. Proceedings of UkrNIISP. Vol. IX, 1964.

15. Danilko G.V., Egorov A.S., Danilyak N.I., Kaminskii R.S. “Kharchova Promislov!st”, 1964, No. 1.

Many people prefer to use alcoholic drinks homemade, since store-bought products do not always meet our requirements. That is why the issue of alcohol purification in winemaking is so relevant. Today we will look at several time-tested and accessible ways for everyone to achieve an ideal result, and answer the question, how to purify alcohol at home?

Purifying alcohol at home - features of the process

Of course, the most radical way is re-distillation. However, there are other ways to purify alcohol at home. Let's take a closer look at them.

The quality of purification depends on the degree of the drink - the lower the degree, the higher the quality of purification of the drink. Until the twentieth century, distilleries produced vodka, the so-called “ bread wine" But with the increase in the quantity and quality of products alcoholic beverages, switched to the production of wheat alcohol, and vodka was obtained by dissolving ethyl alcohol with water.

Important! In some countries, such as Poland and the USA, alcohol is diluted only with distilled water - chemically pure, but without dissolved air and tasteless. This is, in fact, dead water, it is impossible to drink from it, and aquarium fish die instantly in such water.

The main reason for using this technology is to improve the quality and purity of vodka. It is much easier to dilute strong alcohol with good quality water than to purify the smelly water in moonshine.

Important! The quality of water for diluting wheat alcohol is of great importance, since it is water that determines the taste finished products, in which 60% water and 40% alcohol.

In the CIS countries, ethyl alcohol is only diluted raw water. Spring water is traditionally considered the best for this purpose. Of course, ideally, it should be clean, transparent and with a high salt content, but within acceptable limits. If the water is too hard, a ring forms on the neck of the bottle and sediment forms, and consequently the taste of the drink deteriorates. Water that is too hard must be purified and softened using multi-stage filters.

Living water - purifying alcohol

To clean alcohol from bad odors and harmful impurities using this technology yourself, you will need:

• Hydrometer ( special device, which shows the amount of alcohol in the drink).
• Soft spring water.

Proceed as follows:

1. Take a hydrometer and insert it into a container with alcohol.
2. Add water to the container until the hydrometer reads 45 degrees.

Cleaning alcohol with soda

Soda is the most accessible and familiar remedy that is present in any kitchen. The method is based on chemical reaction acetic acid contained in alcohol, and sodium bicarbonate (soda). Due to the interaction of the components, acetic acid is neutralized, and accordingly, you can somewhat purify the alcohol at home.

For cleaning you will need:

Use the components as follows:

1. Dilute baking soda with water, maintaining a 1:1 ratio.
2. Pour the resulting solution into a container with alcohol.
3. Mix the contents well.
4. Let it brew for 30-40 minutes, stir again.
5. Place the jar overnight - choose a dark place.
6. In the morning, drain the drink, additionally filtering it through a layer of cotton wool and charcoal.

Cleaning with potassium permanganate

Using potassium permanganate, you can successfully purify moonshine. This method is known even to those who have never made alcoholic beverages.

To carry out the cleaning procedure you will need:

• Potassium permanganate at the rate of 2 g per 1 liter of drink.
• Glass container or any transparent container.
• Funnel.
• Cotton wool.

Step-by-step instruction:

1. Add potassium permanganate to a container with an alcohol-containing drink.
2. Stir the hot drink well.
3. Leave to settle for 10-20 hours.
4. After a certain time, you will see sediment at the bottom of the jar. These are harmful impurities.
5. Filter the drink through a layer of cotton wool. Place cotton wool at the bottom of the funnel and drain the liquid into a clean container.

Important! To make the cleaning process more effective, close the jar with the alcohol-containing liquid with a lid and keep it in a water bath for 10-15 minutes. The water temperature should not be higher than 60 degrees (do not put in boiling water). This method will help you get rid of the cloudiness of moonshine.

We use black bread

Fusel oils are perfectly absorbed by black bread. Alcohol is not only purified using this method, but also acquires pleasant aroma of bread. Our ancestors also used this method. However, it is better to use it as a “final chord” in order to purify alcohol at home with the utmost quality, following the previously listed methods.

Use Rye bread for the cleaning method is very simple:

1. Dip a piece of bread into a jar of alcohol.
2. After a few hours, when the impurities have been absorbed, remove the baked goods.
3. Strain the drink through a filter to remove any bread crumbs.

How to clean moonshine with egg whites?

Many experts advise cleaning the product only egg white. This method is based on the property of proteins to coagulate under the influence of alcohol. In addition, protein perfectly absorbs various impurities. It is in this way that meat broth is clarified in cooking.

Important! Instead of egg white, you can use milk, since it also curdles under the influence of alcohol. For 1 liter of moonshine you need 200 ml of milk. Pour milk into alcohol-containing liquid, and after curdling dairy product, filter the strong drink.

Proceed in the following order:

1. Get something fresh a raw egg(for a 3-liter jar - 1 egg).
2. Separate the white from the yolk.
3. Dilute the protein a little with water and beat.
4. Pour the mixture into an alcohol-containing drink.
5. Leave the container with the liquid for 1-2 days in a dark place.
6. Carefully drain the product so that the sediment remains in the jar.
7. Filter the drink thoroughly.

Important! Use this method when the strength of the drink is not lower than 50 degrees, since at lower strengths the protein will coagulate poorly. Use this method after all distillations so that the final product does not have the smell of a boiled egg.

Freezing

An effective method for purifying alcohol-containing drinks is freezing. This method will remove the cloudy sediment from the moonshine and make it stronger. When frozen, fusel oils attach to the walls of the container, and only pure alcohol will remain in the container. To purify alcohol at home, the temperature must be very low:

• freeze vodka at -29 degrees Celsius;
• wine at -5 degrees C.

Place the drink bottle in freezer. After freezing, pour the clean drink into another container; all harmful impurities will turn into ice.

Important! The bottle for the freezing method must be strong enough so that it does not burst from the liquid expanding due to frost.

Classic coal cleaning

Activated carbon is an excellent absorbent. It absorbs unpleasant odors and absorbs harmful substances. Therefore, this method is one of the best if you want to clean alcohol safely and with minimal effort at home, and time is not of much importance to you.

Use activated carbon as follows:

1. Grind the product into powder.
2. For cleaning, take 1 tablespoon of coal per 1 liter of product.
3. Add crushed coal to a strong drink.
4. Mix thoroughly.
5. Let it sit for several days (15-20).
6. Shake the drink twice a day so that the entire product participates in the reaction.
7. After the expiration date, filter the drink through a clean cloth or cotton wool filter.
8. Repeat the process several times, replacing old coal with new one.

Important! Activated carbon can also be used to prepare a simple carbon filter:

• Place a small layer of cotton wool in the funnel, gauze on top, and then crushed coal.
• Cover the coal with gauze to prevent it from floating during filtration.
• Pass the alcohol-containing drink through a funnel with a filter.

As a result you will get pure product, since coal will absorb all harmful substances.

How to evaluate the result?

The purity of alcohol can be checked at home. For this:

1. Take the glass or mirror and wash it thoroughly using additive-free cleaning products.
2. Do not wipe the glass, let it dry on its own, then there will be no streaks. Place a few drops of alcohol-containing drink on the cleaned glass. If there are no traces left on the glass, then there are no fusel oils or impurities in the alcohol.

Important! To check again, pour distilled water over the glass. With high-quality cleaning, water will not roll off, as on oily surfaces.

We hope that thanks to our information, you will find an accessible and inexpensive way to purify intoxicating drinks at home. And let the best and purified home-made drinks be the decoration of the festive table.

Previously, water-alcohol solutions were purified from impurities in everyday life using the following methods: 1) filtration; 2) freezing; 3) treatment with protein-containing substances. In industrial alcohol and vodka, along with the latter two, methods were used based on the following phenomena: 1) preferential dissolution of impurities in certain substances, such as oils; 2) salting out.

Filtration. Filtration was carried out by passing an aqueous-alcohol solution through certain filter materials, due to which droplets of fusel oil and mechanical particles were partially separated from it. Filters were made from various materials, but preference was given to charcoal, felt, flannel, soldier's overcoat cloth, washed sand with particles of a certain size. Often these materials were used simultaneously.

Freezing. This method is based on the rule that the solubility of substances decreases with decreasing temperature and this decrease in solubility is different for different substances. This is how this method is described in: “Freezing was a purely Russian and very cheap... technique. But it gave an excellent effect. Thanks to Russian severe frosts, as well as the preservation of huge glaciers in the summer, which practically held ice until the fall, freezing large batches of vodka was not possible complex. Vodka was frozen in special small barrels that had an exposed bottom or a special plug, through which the alcohol that had not frozen in the cold was drained. All the water contained in the vodka, with fusel oil frozen to it in the form of a thin layer, turned into an ice piece that was easily thrown away ".

It should be noted that, in our opinion, since during freezing the proportion of water in the solution continuously decreases and the proportion of alcohol increases, and all impurities that are poorly soluble in water are highly soluble in ethyl alcohol, this purification method is ineffective. In this case, there is no purification from impurities that have high solubility in water. Thus, according to “... it turned out that with a content of 1-2% isoamyl alcohol, the ice is pure, and the isoamyl alcohol remains entirely in the alcohol solution.”

Treatment with protein-containing substances. This method is based on the ability of ethyl alcohol to coagulate (collapse) colloidal particles of proteins in water and form large flocculent aggregates from them. The resulting flakes capture the smallest solid particles and droplets of fusel oil present in the solution being purified and slowly settle. According to some data, proteins selectively absorb (adsorb) molecules of other impurity substances present in an aqueous-alcohol solution. As follows from the literature, a single treatment with alcohol is not very effective. But repeated use, although it leads to increased loss of alcohol and prolongation of the purification process, gives a product of very high quality. To purify alcohol, milk, egg white, whole eggs, and fish glue are used. Cleaning is carried out as follows.

Take 1-2 (more is possible) egg whites or the same number of whole eggs per 1 liter of aqueous-alcohol solution. First, they are beaten, then mixed with a small amount of water, added to the solution to be purified and mixed, since protein flakes are formed almost instantly. After this, the mixture is either left alone for several days until the flakes completely precipitate, after which the purified solution is separated from the flakes with the impurity particles captured by them by decanting, or filtered several hours after treatment.

Technologies for purifying alcohol and sorting using milk are given in. According to Wilke's recipe, "... for 100 liters of alcohol, about 3 liters of milk are consumed, the effect of which is explained by the fact that the clot (protein flakes) formed when mixed with alcohol envelops particles of fusel oil and carries them into sediment. After mixing with milk, the alcohol was rectified and since in the past the distillation was carried out over bare fire, straw was laid on the bottom of the cube to prevent the milk from burning. Nowadays, you can find in the recipes for preparing liqueurs instructions for the use of milk, which is believed to give the product a lighter taste, liquid At the end of the action it is not distilled, but only decanted from the sediment."

According to "... Whole milk is considered unsuitable because the fat it contains can change taste properties in an undesirable direction. Lean milk is more suitable for all high-percentage alcoholic liquids, especially for vodkas of all kinds. Drink from 0.25 to 1 liter of milk per 100 liters. First, add a small amount of water to it and, after thoroughly stirring with a whisk, immediately add this mixture to the main mass of the liquid to be clarified. In this case, the protein coagulates into flakes and after 1-2 days, and often after a shorter time, lightening is observed. When, after prolonged aging, the product becomes crystal clear, it is drained from the sediment and only the cloudy part is subjected to special filtration."

This is how it is described modern technology sorting cleaning using dry milk in the work: "Dry milk is introduced into the sorting of Posolskaya vodka skimmed milk in the amount of 6.2 kg per 1000 dal.

Powdered milk is first poured into 20 dal of water, stirred and after 2-3 hours introduced into the water-alcohol mixture. After adding milk, the sorting is mixed and left alone to settle for 2-3 hours. Under the influence of alcohol, coagulation of the milk protein occurs, which ends with the precipitation of a flocculent substance. The flakes sorb organic and coloring substances contained in the water-alcohol mixture on their surface, entraining them into sediment. Thanks to this, vodka acquires a crystal shine and high taste."

Currently in industrial technology For the preparation of high-quality vodkas from the listed protein-containing substances, only skim milk powder is used in accordance with GOST 10970-87. This milk is produced from pasteurized skim cow's milk or a mixture of it with buttermilk by condensation and subsequent drying and must meet the following physical and chemical parameters (in%): mass fraction of moisture - no more than 4.0; mass fraction of fat - no more than 1.5; mass fraction of protein - not less than 32.0; mass fraction of lactose - not less than 50.0. Removing impurities using oils. The method is based on the experimentally established fact of the high solubility of fusel oil alcohols in some liquid hydrocarbons and dietary fats, in particular in heavy and light petroleum oils, paraffins, poppy and olive oils, etc. Ethyl alcohol, if sufficiently diluted with water, does not dissolve in these substances. Due to the fact that impurities such as aldehydes are also not soluble in hydrocarbons, before treating an aqueous-alcohol solution with oil, the latter is treated with an alkali solution. In this case, the aldehydes are imerized and become soluble in oil. Various oils can be used to extract fusel oils, but industrial production preference was initially given to liquid vegetable oils, later - petroleum oil, having a boiling point of about 240°C and a density of 0.85-0.88 g/ml (note that oil, which according to the modern classification is called solar oil, has characteristics close to those given). So, according to, to purify alcohol from fusel oil "... back in 1858 Breton (later Martin) used poppy seed and olive oil, soaking flannel or pumice with them and filtering raw alcohol through filters prepared in this way, it was assumed that fusel oil was retained in the filter material. The strained alcohol was then subjected to rectification, and in the distillate, according to the observations of I. Kozlov and others, the smell of fusel oil was not noticed, but the smell of consumed fatty oil was noticed. To regenerate the latter, the filter material can be heated using superheated steam, and fusel oil is distilled off, but some of the vegetable fat is also lost.

In 1884, Bang and Ruffin published a method for purifying crude alcohol by treating it with petroleum hydrocarbons, which, without mixing with water or a weak alcoholic liquid, can extract from the latter higher alcohols, ethers and other substances that form fusel oil. According to initial assumptions, light hydrocarbons (petroleum ether) were used for this purpose, but then Bang and Ruffen gave preference to heavier ones, having a density of 0.81 to 0.82... Recently, petroleum oil with a specific gravity of 0.85 has been used - 0.88 g/ml."

According to, in industrial conditions this technology was carried out as follows: “The purified alcohol, previously diluted with water to a strength of 25-30 °, enters a neutralization vat, into which the appropriate amount of lime milk is poured. The vat is equipped with a stirrer, the blades of which can be raised or lowered using a chain , attached to the upper end of the vertical axis. Stirring is continued until the litmus paper lowered into the vat accepts of blue color, i.e. it will not detect an alkaline reaction. The purpose of lime treatment is to neutralize free acids, as well as to decompose esters and polymerize aldehydes. At the end of the reaction, the stirrer is stopped and the liquid is allowed to become clear, and when the lime has settled to the bottom, the solution is lowered into an extraction apparatus, and the solution is washed with petroleum oil. A new portion of aqueous-alcoholic solution is poured onto the lime mortar, the strength of which is far from being lost at one time, after which the stirrer is again put into action, etc. Only after many operations the old lime, almost completely neutralized, is replaced with fresh lime milk, which , in turn, serves for a number of operations. The extraction apparatus, into which the lime-treated aqueous-alcohol solution enters, consists of a conical vat... The lower part of the vat includes a pipe for petroleum oil, perforated inside the extractor with thin holes upward; Under the cover there is a hole in the drain pipe and the level of the solution to be cleaned should be 15 cm below this hole, and the gap from this level to the drain hole is filled with petroleum oil, under which the alcohol cannot evaporate.

The operation of the device is as follows: after pouring in a water-alcohol solution and a protective layer of petroleum oil, start the pump and inject oil through the lower pipe. Rising upward, the streams of oil are saturated with fusel impurities and on the surface merge with the oil layer, and the latter, as it thickens from below, flows through the drain pipe into the cleaning vessels. In these vessels, the petroleum oil leaves all the impurities it extracted from the aqueous-alcohol solution, and, leaving there, in a state of initial purity, is again taken up by the pump and injected into the extraction apparatus. This circulation of oil from the apparatus to the purifiers, and from there through the pump back to the apparatus, continues continuously until the aqueous-alcohol solution is completely purified. After this, the pump is stopped and the liquid is allowed to settle, and all the oil floats up, taking impurities with it. The aqueous-alcohol solution purified in this way is sent for distillation." According to D.I. Mendeleev, "...liquid oils, lubricating oils of petroleum and other similar substances (for example, paraffin), almost without dissolving in alcohol, are extracted from it by fusels oils... and purify the alcohol, which after secondary distillation (or during it) is cleared of most impurities by this method. I personally experienced cleansing through shaking with lubricating oils diluted alcohol, combined with filtering through coal and distillation, gave alcohol of very high purity...” According to the use of paraffin, it is more advisable, since the alcohol purified by it, unlike purified by liquid petroleum oils, does not have the smell of oil. Usually when cleaning pieces paraffin was loaded into the cube together with the distilled liquid in such an amount that after their melting (melting point - 55-60 ° C) a layer of liquid paraffin 1.5-2 cm thick was formed on the surface of the distilled liquid. Ethyl alcohol evaporating during the distillation process passes through this layer, and the alcohols of fusel oil dissolve and remain in it.

We tested the purification of an aqueous-alcohol solution using refined sunflower oil. Roasted seed oil is less suitable for this purpose due to its strong aroma. An aqueous-alcohol solution with a strength of 28-30°, obtained as a result of distillation of mature mash “to the end,” was subjected to purification, i.e., until the alcohol was completely separated. The liquid had an unpleasant fusel smell and dull appearance. 20 ml of oil were consumed per 1 liter of solution.

Purification was carried out as follows. After pouring 10-15 liters of the solution to be purified and the appropriate amount of oil into a 25 liter bottle, the container was shaken vigorously. for 40-60 s. This operation was repeated 2-3 times with intervals between shaking of 1-2 minutes. Immediately after the shaking stops, the liquid begins to separate into two layers: the upper one, which is sunflower oil with substances dissolved in it, and the lower one, which is an aqueous-alcohol solution with tiny droplets of oil. The amount of the latter decreases over time, but even after 20 hours complete release of oil does not occur. 12^ after the end of shaking, the bottom layer was drained using a siphon. Visually, this liquid has a cloudy color and a faint odor of sunflower and fusel oils. The top layer remaining in the bottle has a pronounced smell of fusel oil, drowning out the smell of sunflower oil. The oil and the substances it contained were poured into a metal container.

The container was subjected to regeneration by heating it at 140-150°C for 20-30 minutes until the smell of fusel oil completely disappeared. The reclaimed oil was reused, and the oil-treated aqueous-alcohol solution was distilled. At the same time, the first and middle portions of the distillate had an extremely faint smell of fusel oil, which intensified somewhat as the distillation progressed towards its end. However, even in the last fractions it was insignificant and the distillate was completely transparent.

In our opinion, incomplete cleaning is due to a number of reasons. First of all, this is due to the presence of fusel oil components in the solution, which have significant solubility in water and ethyl alcohol, due to which they are poorly absorbed sunflower oil. In addition, in addition, a solution with a certain number of tiny droplets of sunflower oil containing fusel oil components dissolved in it, which are also released during repeated distillation, is sent for re-distillation. The smell of sunflower oil is completely eliminated, and the smell of fusel oil is weakened even more if before re-distillation Filter the oil-treated solution through charcoal or bone charcoal.

The cleaning effect is enhanced if the aqueous-alcohol solution to be purified is diluted with water to a strength of 20-25° or lower before mixing with sunflower oil and (or) the mixture is kept with the oil for 3-4 days. However, much more effective in terms of reducing both the time and the degree of purification is re-cleaning the solution with fresh or regenerated oil, combined with filtering through coal.

It is also effective to add caustic solution (NaOH) to the purified sunflower oil solution, which is introduced into the distillation cube in the form of a solution immediately before distillation. Under the influence of soda, when boiling, the esters of sunflower and fusel oils are saponified and acids are neutralized with the formation of non-volatile substances. For 1 liter of oil-treated aqueous-alcohol solution, about 1.5 g of NaOH is sufficient. When using NaOH, filtering the oil-treated solution through carbon does not have to be carried out.

Salting out. The starting point for this purification method is the experimentally established facts of the limited solubility of many components of fusel oil in an aqueous-alcohol solution and a decrease in their solubility when certain substances are added to this solution. In a simplified way, we can assume that the water-alcohol solution obtained as a result of the first distillation is a system in which one part of the molecules of fusel oil is evenly distributed between the molecules of water and ethyl alcohol (that is, it is in a dissolved state), and the second part is combined into the smallest droplets. These droplets have a density close to the density of an aqueous-alcohol solution, and as a result, they are also small in size

Evenly distributed throughout its volume. It is clear that an increase in the density of the solution will lead to an increase in the lifting (buoyancy) force acting on these droplets, as a result of which they float to the surface of the solution, from where they can be removed even mechanically. In practice, this increase in density is easy to achieve by introducing into the solution substances that have significant solubility in water, but are not soluble in droplets of fusel oil. However, increasing the density of the solution will not lead to its complete purification from all components of fusel oil, since some of them still remain dissolved in it. Therefore, it is desirable that the substance introduced into the solution not only increases its density, but also simultaneously weakens the bond of molecules of water and ethyl alcohol with the molecules of fusel oil, that is, reduces the solubility of fusel oil in water and ethyl alcohol, as a result of which fusel oil molecules should be separated from solution, combine into droplets and also float up. A water-alcohol solution treated with such a substance will be freed from fusel oils, but it is not suitable for use due to the low concentration of ethyl alcohol and high concentration dissolved substance. This deficiency can be eliminated by distillation. But this purification method places new demands on the solute; it must be non-volatile, chemically inert to ethyl alcohol and the material of the containers used. The purification method by distillation requires that this substance help reduce the bond between water molecules and ethyl alcohol. Fulfilling this requirement is especially important, since it leads to an increase in the rectification coefficient of ethyl alcohol and provides the possibility of its additional purification during the distillation process. At the same time, a decrease in the bond between the molecules of ethyl alcohol and water should not lead to the fact that water and ethyl alcohol separate and ethyl alcohol, together with fusel oil, ends up on the surface of the water.

It would seem that the most suitable substances for purifying a water-alcohol solution from poorly soluble components of fusel oil could be salt(NaCl), due to its availability, low cost, relatively high solubility in water (36.0) and density (2.16 g/cm), 3 also calcium chloride (CaCI2) - extremely hygroscopic “highly soluble in water (59, 5°, 159) substance. However, due to the fact that in comparison with solubility in water, the solubility of NaCl in aqueous-alcohol solutions is greatly reduced, for example, in a 30° aqueous-alcohol solution it is only 14, table salt is of little use for these purposes. As for CaCl, using it, you can easily ensure the required density of the aqueous-alcohol solution, but this salt reacts chemically with ethyl alcohol, which is why it is also unsuitable for these purposes.

In technology industrial cleaning The most widely used alcohol is potash (potassium carbonate K2CO3). (Potash is a white salt or, depending on the degree of purification, yellowish in color, very hygroscopic, density - 2.43 g/cm, solubility in water: 112 g in cold and 156;:. solubility in 30° aqueous-alcoholic solution is about - 30. Note that in industry and in everyday life for a long time The raw material for the production of potash was exclusively ash from trees, grass, cereal straw, and sunflower stems, from which it was extracted by dissolving it in water. On average, from tree ash you can get 10%, from grass, straw and, especially from sunflower stems, about 30% of potash by weight of ash.

Methods for purifying alcohol from fusel oil using potash are described in. Excerpts from both of these works are quoted below, since the information presented in them, complementing each other, allows us to get a more complete picture of the mechanism of this process.

The work states that "...if saline solutions certain concentration- potash, ammonium sulfate, magnesium sulfate - added in a certain ratio to crude alcohol, it is observed that a dark, unpleasant-smelling liquid layer settles above the liquid, which, when the proper concentration is selected, contains all the fusel oil, as well as the head products . Potash subsequently turned out to be the best, because due to its neutralization of acids and its decomposing effect on aldehydes, it was always a valuable purifying agent for raw alcohol. Purification using this method is carried out as follows: per unit volume of crude alcohol at 80 vol.% I take about 4-5 volumes of potash solution, specific gravity 1.235^1.240 g/ml at 15°C, corresponding to the content of 295-302.5 g of salt in liter. The potash solution is heated in an iron cylinder* to approximately 60 C and, with constant stirring, 80 vol.% alcohol is added to it until a layer equal to 1/30-1/60 of the total volume of liquid is formed. For alcohols of other strengths, the concentration of potash solution should be changed accordingly. Add raw alcohol using a pipe reaching almost to the bottom of the vat, stirring with a stirrer. When it is noticed that the top layer has the proper thickness, it is then lowered into a separate vessel using a special draining device and the next layers are separated. Once the layers are removed, distillation begins."

The same method is described as follows: “The method... is based on the separation of fusel oil from alcohol by specific gravity. The purified alcohol is poured into a specially designed vessel and a certain amount of potash or sulfate is added to it, in dry form or in the form of a concentrated solution* ammonium. After some time, the mixture will clearly separate into two layers, which can be accelerated by slightly heating the vessel. All impurities should go into the upper layer, i.e. ethers and fusel oils with a small amount of alcohol. The thicker this layer, the more it carries away alcohol, and therefore, to reduce loss, it is necessary to regulate the thickness of the upper layer by successive additions of water, heating or cooling.If the matter is carried out properly, in the lower layer there will remain, in addition to the added salts, pure alcohol with an insignificant admixture of fusel oil (we will also add water).

The following proportion of materials gives the best result: dissolve 30 to 40 kg of potash or a corresponding amount of ammonium sulfate in 100 liters of water and add 40 liters of purified alcohol to this solution, the strength of which is assumed to be 80 vol.%. The temperature during the operation should be from 20 to 40 C. At this temperature, the mixture of liquids is clearly divided into two layers and the upper layer can be easily increased or decreased as desired by moderately heating or cooling the vessel, or by adding water or salt. You can also do the opposite of the above, namely: first pour raw alcohol into the vessel, and then add the Salt solution, maintaining, however, the same proportions and temperature. The addition of solid salts, although possible, is less recommended. Having decanted the top layer of liquid, if necessary, you can add a small amount of potash to the bottom layer or moderately heat the liquid, on the surface of which a new layer, containing fusel oil residues. Having combined both decanters, first of all, the ethyl alcohol that has passed into this part of the liquid along with fusel oils is extracted, for which the decanter is treated according to the above method with a concentrated solution of potash or ammonium sulfate.

The final result is a very concentrated fusel essence, which can be utilized in perfume production, turning it into aromatic esters. The lower layers of liquid, which are a mixture of brine solutions with ethyl alcohol, enter a simple distillation apparatus to distill off the alcohol, which is obtained in its pure form. As for the salts remaining from distillation, they can be used for the following operations. In addition to potash and ammonium sulfate, many other salts can be used to purify alcohol using the described method... All these substances tend to release fusel impurities of alcohol into the upper layer. The process order and temperature do not change. When using alkaline materials, chemical purification occurs in part, namely the neutralization of the acids contained in the solution, but the main result is achieved here in any case mechanically."