SU777060A1 - Method of ethanol extraction from wine precipitate contaning berling blue - Google Patents

Description

which is processed by one of the known methods.

Treatment of precipitates with Prussian blue with alkali before distillation is carried out to prevent the formation of hydrogen cyanide, a strong poisonous substance. As a result of the treatment of nj, the elute when heated and vigorously agitated, the acid salts of carboxylic and hydroxycarboxylic acids are converted into medium ones, which later, during distillation, prevents the decomposition of Prussian blue to form hydrogen cyanide. The treatment of precipitation with alkali is optimal, because, firstly, at pH; 8, an undesirable process of decomposition of the Berlin blue to form HGN occurs, and at pH 9 a strong foaming during distillation; secondly, at a temperature below 40 ° C, the process of converting the acid salts of carboxylic and hydroxycarboxylic acids slows down on average, and at temperatures above 50 ° C, alcohol is lost.

Acidification and aeration of the distillation-alcohol-bath before secondary distillation is carried out to remove traces of hydrogen cyanide. During acidification, a strong acid, such as sulfuric acid, displaces a weak acid, which is carried away during aeration. Since there can be nitriles of carboxylic and hydroxycarboxylic acids in the distillate, secondary distillation at pH 2.5-3.2 is carried out to destroy them. Under these conditions, the nitriles of carboxylic acids are oiled and converted into ammonium salts, which remain as ammonium sulphate in the residue.

The modes of processing the distilled alcohol raw acidification and aeration are optimal because, firstly, at pH; 2.5 possible corrosion of equipment during secondary distillation, and at pH 3.2 the process of removing traces of hydrogen cyanide and saponification of carboxylic acid nitriles slows down; secondly, the aeration of the distillate for less than 30 minutes does not completely remove traces of hydrogen cyanide.

Example 1. 3l of wine sediment (pH 3.2) with a strength of 8.8 vol. % Bluefin containing 9.2%, tartaric acid salts 0.45%, yeast, bentonite and glue residues 3.4%, heated to 50 ° C and 72 ml of 20% NaOH were added with vigorous stirring for 30 minutes . The slit treatment is carried out until a pH of 8.0 is reached. The mixture is transferred to a distillation apparatus and distilled with steam at 100 ° C. As a result of distillation, raw alcohol of 41.2 vol.% Strength is obtained. % Hydrogen cyanide content is 30 mg / l.

To remove hydrogen cyanide, the alcoholic alcohol is treated with an aqueous solution of sulfuric acid (dilution 1:10) to a pH of 2.5 and aerated at 25 ° C for 30 minutes by sparging with a stream

of air. After aeration, dissolved hydrogen cyanide (HCN) was not detected, however, carboxylic acid nitriles were detected. The nitrile content in terms of HCN 20 mg / l. To destroy the nitriles, the raw alcohol is distilled in the presence of sulfuric acid (RP 2.5) at 100 ° C. As a result of the secondary distillation, ethyl alcohol is obtained with a strength of 70.4%. No cyanic compounds in the secondary distillate were detected.

VAT residue containing Prussian blue and neutral salts of tartaric acid, processed by the known

way.

Example 2. 210 l of wine sediment (pH 3.5) with a strength of 7.2 vol. %, containing Prussian blue 7.3%, salts of tartaric acid, 0.38%, residues of yeast, bentonite and glue substances 2.9%, heated to 40 ° C and with constant stirring, 13 kg of technical NaOH dissolved in 100 liters of water. Stirring is carried out for 3 hours. After stirring, the mixture has an alkaline pH of 9.0. The treated sludge is transferred to a facility of periodic type UPK-58-02. As a result of the primary distillation, 325.2 l of raw alcohol of 43.7% strength is obtained. For

removing traces of hydrogen cyanide (21 mg / l), the resulting crude alcohol is transferred into an enamel container, an aqueous solution of sulfuric acid (dilution 1:10) is added to a pF 3.0 and aerated

at 20 ° C for 60 min. After aeration, the raw alcohol is distilled in a bottom unit to remove the nitriles of carboxylic acids (in terms of HCN 17 mg / l). After the secondary distillation receive

205.3 liters of ethyl alcohol with a strength of 67.2 vol. % No cyanic compounds in the secondary distillate were detected.

The proposed method allows to prevent environmental pollution.

cyanide compounds during distillation,

get ethyl alcohol free from

cyanide compounds, and reduce wear

equipment 1.5-2.0 times.

The expected economic affect of

use of the proposed method will be 300 thousand rubles.

Claims (2)

1. A method of extracting ethanol from a Berlin blue wine precipitate, which involves distilling it to produce raw alcohol, treating it with alkali and distilling crude alcohol, characterized in that, in order to prevent environmental contamination with cyanide compounds during distillation, the treatment with alkali before being distilled, the wine precipitate is subjected to a pH of 8–9 at 40–50 ° C for 0.5–3.0 h, and the alcohol – source is distilled to a pH of 2.5–3.2 before distillation and aerated at 20-25 ° C for 30-60 minutes. 2. A process according to claim 1, characterized in that sulfuric acid is used for acidification. 3. The method according to claim 1, characterized in that the distillation of the wine precipitate with Prussian blue and crude alcohol is carried out at 80-100 ° C. 6 Sources of information taken into account in the examination 1. Proceedings of the Georgian Food Industry Research Institute, 1971, 5, p. 50-52, 2. Beridze, G.I. and others. On the processing of wine sediment with Prussian blue. Wine-making and viticulture of the USSR, 1971, 5, p. 48-50 (prototype).