RU2553220C2 - Method for producing ethanol - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method provides producing ethanol by ethanol extraction from fermentable wort in a distillation column, wash distillate cleaning from head and intermediate impurities in an epuration column operating by deep hydroselection, epurate rectification in an alcohol column, impurity recovery in a final purification column operating in the mode of re-epuration and purification of fractions containing head impurities and methanol in a head impurity concentration column. The alcohol column, final purification column and head impurity concentration column operate in vacuum and are heated by secondary alcohol water steam from other columns; between the alcohol column and final purification column, there is an ion exchange reaction for recovering impurities having the negative effect on the organoleptic parameters of the end product.

EFFECT: invention enables improving the organoleptic parameters of ethanol, improving its qualities and reducing the production-related energy consumtion.

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Description

The invention relates to methods for producing ethanol.

A known method is provided for the digestion of ethyl alcohol from a mash in a mash column with the passage of ethyl alcohol and associated impurities into the mash distillate with steam from this column and liquid fractions from the condenser of the carbon dioxide separator and alcohol traps, the separation of impurities from the mild distillate in the pasteurization column, strengthening and pasteurization ethanol and the removal of fusel oil components from the zones of their concentration in the alcohol column operating under vacuum and heated by the heat of the beer column. The alcohol column has zones of high concentrations of ethanol, aldehydes and other active compounds capable of chemically interacting under harsh production conditions; therefore, the operation of this column (therefore, other columns with a high concentration of ethanol and impurities in the upper zones: the final column and the column for concentration of impurities) at low pressure (temperature) contributes to a better finished product (Tsygankov P.S. Guide to rectification of alcohol / P.S. Tsygankov, S.P. Tsygan s // M .: Pischepromizat, 2001, 2002, pp. 73, 74). In addition, lowering the pressure increases the evaporation rates of most impurities of ethyl alcohol, which contributes to its better cleaning.

However, this method is not without drawbacks, since in the process of epuration there is an incomplete release of methanol, components of fusel oil and other intermediate impurities. These impurities pass with the epure into the alcohol column and partially get into the final product, reducing its quality.

Atmospheric pressure recovery plants equipped with additional columns make it possible to obtain

deeply purified ethanol, but the cost of the finished product is very high. The aim of the invention is to reduce the energy consumption for rectification while maintaining the quality of ethanol.

Closest to the proposed method is the production of ethanol (RF Patent No. 2342432, Method for the production of ethanol / Nikitina S.Yu., publ. 27.12.2008), which involves the digestion of alcohol from mash in mash column with the transition of ethyl alcohol and related impurities in mash distillate with steam from this column, purification of the distillate from the head and intermediate impurities in an epilation column working according to the hydroselection method, distillation of the epureate in an alcohol column with selection of fractions of fusel oil, fusel alcohol and unpasteurized alcohol, distillation of fractions of head and intermediate impurities of ethyl alcohol in the booster column, additional purification of alcohol from head impurities and methanol in the head impurity concentration column, extraction of tail and intermediate impurities in the distillation column from the epuret, removal of organic acids and other tail impurities by selection of luther water from the cube of the booster column. The specified method allows to obtain ethanol of high quality, but metal and energy intensive. In addition, technological violations at the preliminary stages of alcohol production lead to an increase in the content of organic acids and other compounds that are difficult to extract by distillation methods.

The proposed method for the production of ethanol consists in the fact that along with the digestion of ethyl alcohol from the mash in a mash column operating under excess pressure, with the transfer of ethyl alcohol and associated impurities to the mash distillate with steam from this column, the mash of distillate is removed from head and intermediate impurities, including fusel oil components, in an overhead pressure scrubbing column using deep hydroselection, distillation of the epurate taken from the liquid phase of the middle zone plates part of the epilation column, in an alcohol column heated by the secondary steam of the brew column, with the selection of fractions of fusel oil, fusel alcohol and unpasteurized alcohol, the separation of impurities in the final purification column operating in the re-epuration mode under vacuum heated by the secondary steam from the epilation column, cleaning fractions containing head impurities and methanol in a column of concentration of head impurities operated under vacuum, heated by the heat of water-alcohol vapors leaving the top s concentration zone of the column, the final purification, to improve organoleptic characteristics of finished products between the column and the alcohol purification column set final ion exchange reactor, where the release of organic acids, nitrogenous compounds and other impurities, negatively affecting the organoleptic characteristics of the finished product.

The technical result achieved by the invention is the production of ethanol of high quality with a simultaneous reduction in energy consumption for fractions rectification.

The drawing shows a flow chart of rectification, explaining the proposed method (figure 1). The initial mash, heated in reflux condensers (pos. 20, 2, 3), is fed to the CO ₂ separator (pos. 6), where carbon dioxide containing vapors of the mash is released from it. Carbon dioxide is purified by vapor condensation in a condenser (pos. 7) and is removed from the recovery unit, and the condensate formed is sent to the clean distillate collector. The separated mash is fed to the nutrient plate of the mash column (item 1), operating under overpressure, where ethanol and volatile impurities are boiled from it. Steam from the top plate of the cooker column (pos. 1) enters the reflux condenser (pos. 13), from where it is sent to the reflux condenser (pos. 2, 3, 4) and the condenser (pos. 5). Non-condensed vapors are discharged into an alcohol trap (item 8). Barda is discharged through the bardoregulator (pos. 9) and sent to the bardoceps (not shown in the diagram). The distillate from the heat exchangers (pos. 2-5, 7, 8) enters the upper nutrient plate of the emulsion column (pos. 10), and from the reflux condenser (pos. 13) (through the tank (pos. 43) by the pump (pos. 46)) - on the lower food plate.

The dressing column (pos. 10) is heated in a closed way through a boiler (pos. 11), it works by the method of deep hydroselection. Hot softened water is supplied to the upper part of the column, which increases the evaporation coefficients of most ethanol impurities, which take on a head character and are removed from the condensation system (pos. 14) through the cooler (pos. 16) and epruvet (pos. 17). Epuret is taken from the liquid phase of the upper plates of the stripping part of the column (pos. 10) and sent to the alcohol column (pos. 19), from the bottom part through a water trap (pos. 12), a luther completely free from ethyl alcohol leaves. Water-alcohol steam is taken from the upper part of the scrubbing column and enters the reflux condenser (pos. 40) to heat the final purification column (pos. 37) operating under vacuum. Non-condensed gases from the reflux condenser (pos. 40) go into the condenser (pos. 14) and an alcohol trap (pos. 15). Condensate from the reflux condenser (pos. 40) enters the collector (pos. 45), and then with a pump (pos. 50) it returns to the upper plate of the recovery column (pos. 10), liquid from the condenser (pos. 14) also enters there and alcohol traps (item 15).

In the alcohol column (pos. 19), equipped with a reflux condenser (pos. 20, 21, 22) and a condenser (pos. 23), the epurate is rectified. The column operates under vacuum and is heated by the secondary steam of the brewing column (pos. 1) through a reflux condenser-evaporator (pos. 13). In this column, the epurate is concentrated and purified from head, intermediate and tail impurities. The fusel oil fractions are taken from the vapor phase of the plates of the boiled portion of the column and sent by the injector (pos. 26) to the condenser (pos. 36) (from the fusel condenser (pos. 36), the liquid enters the decanter (pos. 35), from which the fusel oil, and the fusel layer is discharged onto one of the plates of the boiled portion of the alcohol column (pos. 19), a fraction of fusel alcohol is removed from the liquid phase of the lower plates of the strengthening part of the column and sent by the injector (pos. 25) to the upper zone of the epilation column (pos. 10). The fraction of unpasteurized alcohol is removed from the condenser (pos. 23) and fed with the pure epaulettes from the alcohol trap (pos. 24) to the power plate of the head impurity concentration column (pos. 29). Luther water is discharged from the bottom of the column (pos. 19) through a water trap (pos. 27). Rectified alcohol is taken from the liquid phase of the upper plates of the reinforcing part of the column (pos. 19) and through the ion exchange reactor (pos. 34) it enters the final purification column (pos. 37) operating under vacuum in the re-epilation mode.

Ion-exchange reactor (item 34) (RF patent for utility model No. 106132 “Ion-exchange filter for ethanol purification”) / Nikitina S.Yu., Nikitin AA, Selemenev VF, Rudakov OB, Kudukhova I .G. Publ. 07/10/2010) consists of a cylindrical shell, the ends of which are welded to the bottoms, the upper bottom is double, the resulting volume plays the role of a manifold-distributing device, whereby the filtered fluid is evenly distributed between interchangeable interchangeable filter cartridges. The device is divided by a vertical wall, and two semi-cylindrical volumes are formed, each with its own set of filter cassettes (one of the sets consists of cassettes filled with cateonite, the other with anianite). The device of filter cartridges is standard: between two cylindrical shells from a grid inserted one into another, the filtering substance is placed. Filtered liquid, getting into the central channel of the filter cartridge, the lower end of which is plugged, seeps through the filter in radial directions evenly over the entire height of the cartridge, falling into the space bounded by the semi-cylindrical shell and the inner wall of the reactor, where flows are collected and mixed from all filter cassettes; Further, through a pipe with a flange, the liquid is removed from the device or enters the adjacent manifold volume.

After passing through an ion-exchange reactor, ethanol is sent to the power plate of the final cleaning column (key 37). Methanol and other compounds of a head nature are concentrated on plates of the reinforcing part, a reflux condenser (pos. 38) and a condenser (pos. 39), from where they are removed and sent to the concentration column of head impurities (pos. 29). The finished product is taken from the bottom of the column (key 37) through the refrigerator (key 41) and epruvetka (key 42).

The head impurity concentration column (pos. 29) is intended for additional purification of ethyl alcohol of organic substances having a terminal and head character, which are concentrated in the strengthening part, reflux condenser (pos. 30), are taken from the condenser (pos. 31) and sent together with the fraction from the condenser (pos. 14) of the epilation column to the alcohol reception compartment. A fraction of ethyl alcohol is removed from the bottom of the column and returned to the nutrient plate of the alcohol column (key 19).

The distillation (pos. 1) and emulsion (pos. 10) columns operate under excessive pressure, the alcohol column (pos. 19), the final purification column (pos. 37), and the head impurity concentration column (pos. 29) are operated under vacuum. The vacuum in the system is created by a vacuum pump (key 51) through a barometric condenser (key 18) in communication with the heat exchangers (key 24, 31, 39). To trap alcohol from gases, cold water is fed to the upper plate of the barometric condenser (key 18), and the hydroalcohol liquid from the barometric condenser is sent to the feed plate of the head impurity concentration column (key 29). To prevent scale from entering the vacuum pump, a trap is installed in front of it on the air pipe (key 52).

According to the known method, the heating steam is spent on heating mash, distant, alcohol, booster columns, columns concentration of head impurities. According to the proposed method, only mash and dressing columns are heated with primary steam, which reduces energy costs by more than two times.

The known method does not provide additional adsorption purification of ethyl alcohol. According to the proposed method, the distillation unit is equipped with an ion exchange reactor, where traces of head and intermediate impurities are extracted, which worsen the organoleptic characteristics of the finished product.

Comparative indicators of the process of obtaining rectified alcohol according to the prototype and the proposed method are reflected in examples 1, 2 and are presented in the table.

Example 1. Rectified alcohol is obtained according to the prototype.

Example 2. Rectified alcohol is obtained according to the proposed method.

As follows from the above examples, the proposed method allows to remove more impurities from the system of rectification, to obtain rectified alcohol with lower energy consumption compared to the known method.

Claims (1)

A method of producing ethanol by digesting ethyl alcohol from a mash in a mash column operating under excess pressure, with the transfer of ethyl alcohol and associated impurities to the mash distillate with steam from this column, purification of mash distillate from head and intermediate impurities in a distillation column operating under excess pressure according to the method of deep hydroselection, distillation of the epuret taken from the liquid phase of the upper plates of the distant portion of the epilation column in an alcohol column heated by br important column with selection of fractions of fusel oil, fusel alcohol and unpasteurized alcohol, extraction from rectified alcohol taken from the liquid phase of the upper plates of the strengthening part of the alcohol column, traces of head and intermediate impurities that impair the organoleptic characteristics of the finished product, in an ion-exchange reactor installed between the alcohol column and a final cleaning column, which operates in the re-epuration mode under vacuum and is heated with secondary steam from the epilation column, ki fractions containing impurities head and methanol concentration in the column head impurities operated under vacuum and the heated warm water-alcohol vapors emerging from the upper zone of the final concentration of the column purification.