RU2187353C1 - Method of production of rectified ethyl alcohol - Google Patents

Abstract

FIELD: production of alcohol. SUBSTANCE: proposed method consists in production of alcohol from alcohol mash or from crude rectified ethyl alcohol in mash-rectifying or rectifying plant including mash column, fractionating column and final purification column. Fractionation is effected in hydraulic selection mode by introducing hydroselective water into fractionating column and separation of fractions of alcohol admixtures is performed in this fractionation mode. Below hydroselective water introducing section, distillate containing intermediate admixtures is subjected to splitting and upper oil layer is picked off; this layer contains mainly higher alcohols: propyl alcohol, isobutyl alcohol and isopropyl alcohol which are withdrawal from process. In the course of rectification of mash rectification, circulation of distillate which contains admixtures not separated during hydroselection is performed from rectifying column to fractionating column followed by selection of distillate containing these admixtures from rectifying column. In the course of rectification, rectified ethyl alcohol is obtained which is directed to additional column for final purification. EFFECT: improved quality of alcohol at minimum content of methanol; extended range of high-quality alcohols. 1 dwg

Description

 The invention relates to the food industry, namely to alcohol, and relates to a method for the production of rectified ethyl alcohol from starch-containing raw materials, which is mainly used in the production of hard drinks.

 A known method for the production of rectified ethyl alcohol, including the distillation of alcohol and impurities from the mash, the separation of the stream of water-alcohol vapors leaving the mash column into two parts, followed by purification from impurities, epuration in the epilation column, concentration of impurities in the concentration column and rectification ( USSR author's certificate 1261945, class C 12 F 1/06, 1986).

 The disadvantage of this method is the insufficiently high quality of the resulting alcohol.

 A known method for the production of rectified ethyl alcohol, which involves the epuration of the mash and its release from impurities in the epilation column with the supply of hydroselective (softened or luther) water to the epuretion column and the isolation of epaulettes containing head impurities and components of fusel oil, followed by rectification of the epureate and distillation column components of fusel oil, which did not stand out during the rectification process, in a special column (book: Technology of alcohol and alcohol products. / Ed. iey V.V.Ilinicha. M .: VO "Agropromizdat", 1987, p. 202).

 Obtained by this method, the alcohol, as well as the previous one, has low quality indicators, namely, an increased methanol content (0.3%).

 The closest to the proposed technical essence and the achieved effect is a method for the production of rectified ethyl alcohol, providing for the rectification of alcohol mash or rectification of crude ethyl alcohol in a rectification or distillation unit containing mash, epuretion and distillation columns, conducting epilation in the process of hydroselecting water by hydroselecting by water in the concentration part of the scrubbing column, fractional selection of impurities in this mode, namely, ogon containing the head fraction of ethyl alcohol is taken from the upper zone of the epilation column, directing the epurate freed from impurities to rectification, and a shoulder strap containing intermediate impurities is taken from the epilation column below the site for introducing hydroselective water (RF patent 2136758, class C 12 P 7 / 06, 1999). Obtained by this method, alcohol "Lux" is a high-quality product containing only 0.03% methanol.

 However, it should be noted that even the presence of such an amount of methanol adversely affects the quality of alcohol, especially at present, in the conditions of fierce competition in the market of strong drinks, where quality is a fundamental factor in trade.

 The presence of methyl and propyl alcohols, even in small amounts, worsens the smell and taste of ethyl alcohol, since they have high toxicity (they are poisons).

 So, methanol - 80 times, and propanol - 4 times more toxic than ethanol. Butyl and amyl alcohols have a fusel odor and a burning taste, hexyl alcohols have the smell and taste of rancid oil.

 All of them are poisonous, so they must be completely removed from alcohol. The problem solved by the present invention is the most complete release of alcohol from related harmful impurities, which must be concentrated, maximally free from alcohol and removed from the process. These are intermediate impurities, which may, depending on the distillation conditions, be either tail or head.

 The technical result of the present invention is to improve the quality of ethyl alcohol, rectified by maximally freeing it from impurities and expanding the range of high-quality alcohols.

 The problem and technical result are achieved in a method for the production of rectified ethyl alcohol, providing for the rectification of alcohol mash or rectification of crude ethyl alcohol in a rectification or distillation unit containing mash, epuretion and distillation columns, conducting epilation in hydroselection mode by introducing fractional selection water in concentration mode columns, fractional selection of impurities, namely a shoulder strap containing the head fraction of ethyl alcohol, selected from the upper zone of the epilation column, directing the epurate freed from impurities to distillation, and a shoulder strap containing intermediate impurities is taken from the zone located below the site of the introduction of hydroselective water, characterized in that the shoulder strap containing intermediate impurities is subjected to stratification (decantation), while selecting the upper oil layer containing mainly propanol, which is removed from the process, while circulating a shoulder strap containing residual intermediate B, when nevydelivshiesya gidroselektsii, and selection of their respective zones of concentration of these impurities in the distillation column zone isolation Epuration column and of the lower zone of the distillation column and the resulting alcohol rectification process is directed to the final purification of methanol in an additional column.

 The method is illustrated by the technological scheme (see drawing) of its implementation, according to which the distillate or crude alcohol is served on a food plate of the epilation column 1.

 The scrub column 1 is equipped with a reflux condenser 2, a condenser 3 and a device 4 and is divided by height of the czar into three parts: boiled, hydroselective and concentration.

 Water for hydroselection is supplied to the hydroselection zone in an amount in which the volume fraction of ethyl alcohol in the epuret at the outlet of column 1 was in the range from 15 to 25%. A shoulder strap from the concentration part of distillation column 5, enriched with intermediate impurities (propanol, isopropanol, butanol and others) in an amount of from 0.5 to 1%, is introduced into the same zone of the emulsion column 1.

 Impurities (esters, aldehydes and methanol) extracted during the epuration and hydroselection process are concentrated in the upper part of the epilation column 1, reflux condenser 2, and are removed from the condenser 3 in the form of a fraction of head ethanol from 1.5 to 3%. In the scattering column 1 below the water inlet point, a device 4 is mounted for stratification (decantation) of the fraction into two layers. The upper oil layer, enriched with propanol and other intermediate impurities, is removed from the column 1 in an amount of from 0.5 to 1.5%. Epuret from column 1 enters the feed plate of distillation column 5. In column 5, distillation and concentration of impurities not separated in epuretion column 1 takes place.

 Alcohol vapors from column 5 enter reflux condenser 6, condense in it and return to the upper plate of column 5 as reflux. Non-condensed alcohol vapors from reflux condenser 6 enter condenser 7. Unpasteurized alcohol is selected from condenser 7, which is from 2 to 3 in amount % is directed to the concentration zone of the scrubbing column 1. The distilled alcohol from column 5 is taken from one of the plates of the alcohol selection comb, which are sent to the final purification column 8 for further purification from methanol. From one of the plates of the column 5 from the vapor phase, fusel oil components are removed that are not released during the hydroselection of impurities in the scrub column 1.

 Luther water is discharged from the bottom of column 5. Alcohol vapors from column 8 enter reflux condenser 9, condense in it and return to the upper plate of column 8 as reflux. Non-condensed alcohol vapors from reflux condenser 9 enter condenser 10. From the condenser 10, methanol fraction is collected in an amount from 1.5 to 2 , 5%, which is sent to the upper plate of the column 1. Freed from impurities, rectified ethyl alcohol is removed from the boiled chamber of the column 8.

 Example 1. Rectified ethyl alcohol "Stolny" is obtained in a distillation unit operating under vacuum created by a vacuum pump 11. The plant capacity is 3000 dal / h. Raw alcohol, diluted with water to a volume fraction of ethyl alcohol of 45%, is served on the 20th plate of the nutrition of the epilation column.

 300 ltr / hr of luther water is fed to the 32nd plate of the epilation column having 39 plates. The epaulet from the 42nd plate of the distillation column in the amount of 1.3 dal / h is circulating in the same zone. The volume fraction of ethyl alcohol in the plot at the outlet of the column with this dilution will be 20%.

 The head fraction from the column is removed in an amount of 2.5%. The decantation (stratification) of the epaulettes containing intermediate impurities is carried out in an epilation column below the site for introducing hydroselective water.

 As a result of decantation, the overhead containing alcohols — propyl, isopropyl, isobutyl, esters and other impurities — is removed from the process.

 The epurate with a volume fraction of ethyl alcohol of 20%, freed from impurities, in the amount of 625 dal / h is sent for rectification, from where the alcohol enters the final purification column to free from methanol and ether residues. Alcohol is taken from the final purification column, and the epaulette containing residues of impurities in an amount of 1 dal / h is returned to the scrubbing column.

Example 2. Alcohol "Table" is obtained from mash, which is heated to a temperature of 75 ^o C and served on a plate of food mash columns (not shown).

 The mash column operates at a pressure of 115 kPa. The condensate in the form of a distillate with a volume fraction of ethyl alcohol of 45% is served on a food plate of the scrubbing column.

 Further, the process is carried out as in example 1.

 The table shows the comparative indicators of alcohol "Lux" (analog) and the resulting alcohol "Stolny".

 As can be seen from the table, the resulting alcohol "Stolny" has 10 times less methanol, contains significantly less esters and fusel oil, which give alcohol an unpleasant taste and smell.

 The proposed method allows to obtain high-quality rectified ethyl alcohol "Table" with high physico-chemical characteristics and expand the range of high-quality alcohols.

Claims (1)

 A method for the production of rectified ethyl alcohol, which involves the rectification of alcohol mash or rectification of crude ethyl alcohol at a distillation or distillation unit containing a mash, epuretion and distillation column, conducting epilation in hydroselection mode by introducing hydroselective water into the concentration part of the fractionation column, and fractionation of the fractionation column, it is the epaulette containing the head fraction of ethyl alcohol that is taken from the upper zone of the epilation column, for example pouring the epurate freed from impurities for rectification, and the overhead containing intermediate impurities is taken from the zone located below the inlet of hydroselective water, characterized in that the overhead containing intermediate impurities is subjected to delamination (decantation) in the zone of their separation, while selecting the upper an oil layer containing predominantly higher alcohols - propyl, isobutyl, isopropyl, which are removed from the process, while circulating a shoulder strap containing residual harmful impurities that are not separated When gidroselektsii zone of their concentration in the distillation column in zone gidroselektsii Epuration column, and removing distillate containing residuals from the distillation column bottom zone, and the resulting alcohol rectification process is directed to the final purification of methanol and other impurities in the extra column.

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