RU2440965C2 - Method of processing alcohol production wastes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of processing alcohol production wastes: concentrate of head impurities of ethyl alcohol (CHI) and an intermediate fraction of ethyl alcohol (IFEA). The method involves obtaining a water-alcohol solution of CHI or IFEA with density (0.837-0.940) g/cm³ (I) and conducting continuous extraction of impurities (C₃-C₅ alcohols, esters, carbonyl compounds) in a packed column with a mixture of aromatic hydrocarbons (II) or a mixture of aromatic and aliphatic hydrocarbons (III) with ratio of volume flow I: II or, respectively, I : III, equal to 1:(1-4) (preferably 1:1.2). To intensify mass exchange into solution (I), (0.1-0.5) wt % mixture (IV) of anionic alkyl sulphates and noionic oxyethylated alkyl phenols in ratio (25-20):(70-75) wt% (IV). The desired processing products: raffinate - aqueous of ethanol with weight ratio of the latter equal to (80-20) wt % can be used to obtain high-purity edible ethyl alcohol and as an anti-icing agent for glass used on cars, and extract - solution of alcohol and esters in a mixture of hydrocarbons is used to prepare mixed solvents for the paint industry.

EFFECT: high efficiency of the method of processing alcohol production wastes.

4 cl, 8 ex, 1 tbl, 2 dwg

Description

The invention relates to a method for the processing of wastes from alcohol production: concentrate of head impurities of ethyl alcohol (KGP) and an intermediate fraction of ethyl alcohol (PFES).

The method consists in obtaining a water-alcohol solution (I) from KGP or PFES with a density of (0.837-0.940) g / cm ³ , it is possible to introduce (0.1-0.5)% wt. a mixture of surfactants (IV), consisting of (20-25)% wt. anionic from a number of alkyl sulfates and (70-75)% wt. nonionic surfactants from a number of ethoxylated alkyl phenols, and the continuous extraction of impurities: C ₃ -C ₅ alcohols, esters, carbonyl compounds from solution (I) with a benzene-free hydrocarbon mixture with a boiling point not exceeding 170 ° C: aromatic (II) or aliphatic C ₇ -C ₉ and aromatic with a content of the latter not lower than 60% wt., (III) in the packed column with a volumetric flow ratio of I: II or, accordingly, I: III, equal to 1: (1- 4) (better - 1: 1,2).

Target products of processing: raffinate - an aqueous solution of ethanol with a mass fraction of the latter (80-20)% wt. depending on the density of the solution (I) is used to obtain food grade ethanol with a high degree of purification, and also as an anti-icer for automobile windows; extract - a solution of alcohols and esters in a mixture of hydrocarbons is used to prepare mixed solvents for paints and varnishes.

Description of the invention

The invention relates to the field of chemical technology, and in particular to a method for the processing of waste from alcohol production: concentrate of head impurities of ethyl alcohol (CHP) and an intermediate fraction of ethyl alcohol (PFES).

KGP and PFES are obtained by rectification of the ether-aldehyde fraction (EAF) formed during the primary rectification of crude alcohol. EAF rectification is carried out in order to more fully isolate ethanol. The amount of EAF is 2-6% of the conditional crude alcohol and is a large-tonnage waste. For the separation of mixtures of alcohols contained in the waste of alcohol production, there are many patents. In particular, on the separation of ethanol from various mixtures by hydrogenation with hydrogen [a.s. Czechoslovakia 268100, MKI C07C 29/04, 07/31/1990] or as a mixture with toluene [a.s. USSR 1620442, MKI S07C 31/10, 01/15/1991]. These methods are cumbersome and unsuitable for the separation of QGP and PFES.

There is a patent No. 2272018, 09/11/2004 "Method for the processing of waste from alcohol production (options)", intended for non-waste processing of CHP and PFES. The method is carried out by direct distillation of CGP and rectification of PFES in the MPA-200 mass transfer rotary apparatus in the presence of alkaline agents selected from the series: hydroxides, carbonates, potassium or sodium bicarbonates, calcium oxide, ammonia water, taken in an amount (0.01-3, 0)% wt. and cube temperature (80-86) ° С.

The distillate obtained by distillation of CGP and rectification of PFES is used to prepare solvents for NT varnishes or glass de-icer (binary mixture), bottoms as an additive in heating oil, which increases its fluidity. The method is non-waste.

The disadvantages of this method are the high energy intensity, the need to use corrosion-resistant equipment, and the fact that as a result of treatment with alkaline agents, the esters contained in KGP and PFES are destroyed (hydrolyzed). It is known that esters are the most active part of mixed solvents for paints and varnishes [S.A. Drinberg, E.F. Itsko. Solvents for paints and varnishes. - L .: Chemistry, 1980].

The disadvantages of the method can also include the high water content in the still residue of distillation and rectification, used as an additive in heating oil.

KGP according to the norms of TU 9182-478-00008064-2002 has a composition,% wt .:

- ethanol - 70-88;

- aldehydes, not less than 0.3;

- esters, not less than 3.0;

- methanol, not less than 2.0;

water is the rest.

PFES according to the norms of TU 9189-479-00008064-2002 has the composition,% wt .:

- ethanol - 23-73;

- water - 25-75;

- alcohols C ₃ -C ₅ , not less than 2.

According to the chemical analysis according to GOST 5964-82, clause 2.10 “Rectified ethyl alcohol. Analysis methods "the content of esters in PFES is 0.1-1.0% wt.

The aim of the invention is a non-waste non-energy-intensive method for processing waste from alcohol production - KGP and PFES.

This goal is achieved by preparing a water-alcohol solution from KGP or PFES (I) by adding water to them to a density of (0.837-0.940) g / cm ³ and (0.1-0.5)% wt. a mixture of surfactants (IV), consisting of (70-75)% wt. non-inogenic surfactants from a number of hydroxyethylated alkyl phenols and (20-25)% wt. anionic surfactants from a number of alkyl sulfates to increase the intensity of mass transfer, conduct continuous extraction of higher C ₃ -C ₅ alcohols, esters and aldehydes from (I) with a mixture of aromatic hydrocarbons containing no benzene with a boiling point not exceeding 170 ° C (II) or a mixture of aliphatic C ₇ -C ₉ and aromatic hydrocarbons with the exception of benzene, with a content of the latter not lower than 60 wt.%, and a boiling end not higher than 170 ° C in the packing column at ambient temperature with a volumetric flow ratio of I: II or, respectively I: II I, equal to 1: (1-4) (better 1: 1,2). Extraction products: raffinate - an aqueous solution of ethanol with a content of the latter (80-20)% wt. depending on the density of the solution (I) is used to obtain food grade ethanol with a high degree of purification, as well as as an anti-icer for the windows of Panorama cars according to TU 2384-020-16715043-2008; extract - a solution of alcohols and esters in a mixture of hydrocarbons is used to prepare mixed solvents for paints and varnishes.

At the same time, the content of harmful impurities - methanol in the raffinate does not exceed 0.03% wt., Which is below the norm established for food products (in a technical product - glass defroster is considered to be absent); the methanol content in the extract does not exceed 1.2% by weight, the aldehyde content does not exceed 0.3%, and in the solvents obtained from the extract, the content of these impurities does not exceed, respectively, 0.6 and 0.15% by weight, which is lower than established norms for these impurities. The acid number (c.h.) of mixed solvents obtained from the extract is not higher than 0.15 mg KOH / g, which is much better than the norm established by GOST R 31089-2003 "Solvents for paints and varnishes" (c.ch.≤0, 7 mg KOH / g).

The advantage of the method is that the valuable component (I) - esters are not destroyed, but pass into the extract.

The extraction schemes are shown in FIG. 1 and 2.

To obtain a water-alcohol solution (I), CGP or SFC is continuously supplied from the storage to the mixer, water is also supplied from the process water line and, to intensify mass transfer, it is possible to introduce a mixture of surface-active substances (IV) to a content of (0.1-0, 5)% wt. in solution (I). Upon receipt of the solution (I) with a density of less than 0.860 g / cm ³ it is continuously fed through the side fitting at the bottom of the packed column filled with Raschig rings and a mixture of hydrocarbons (II) or, respectively, (III). Through the lateral fitting at the top of the column, (II) or, respectively, (III) is fed. Through the lateral fitting at the top of the column, raffinate is taken, and the extract is taken from the bottom of the column.

Upon receipt of the solution (I) with a density above 0.860 g / cm ³ it is continuously fed through the side fitting at the top of the column, and (II) or, respectively, (III) through the side fitting at the bottom of the column, the raffinate is taken from the bottom of the column, the extract - from the top.

The process is illustrated by the examples shown in the table and extraction schemes (Fig.1, 2).

Information sources

1. Copyright certificate of Czechoslovakia No. 268100, MKI 4 S07C 29/04, publ. 07/31/1990

2. USSR author's certificate No. 1620442, MKI 5 C07C 31/10, C07C 29/82, C08C 11/02, publ. in BI No. 23, 1993

3. S.A. Drinberg, E.F. Itsko. Solvents for paints and varnishes. - L .: Chemistry. 1998 year

4. RF patent No. 2272018, IPC С07С 31/08, С07С 29/80, publ. 03.20.2006 (analog).

Claims (4)

1. The method of processing waste from alcohol production: concentrate of head impurities of ethyl alcohol (KGP) and an intermediate fraction of ethyl alcohol (PFES), characterized in that an aqueous-alcoholic solution of KGP or PFES with a density of 0.837-0.940 g / cm ³ (I) and conduct continuous extraction of impurities (C ₃ -C ₅ alcohols, esters, carbonyl compounds) in the packed column with a mixture of aromatic hydrocarbons (II) or a mixture of aromatic and aliphatic hydrocarbons (III) with a volumetric flow ratio of I: II or I: III, respectively 1: (1- 4) (better than 1: 1.2). 2. The method according to claim 1, characterized in that for the intensification of mass transfer into the solution (I) it is possible to introduce 0.1-0.5 wt.% A mixture of anionic surfactants from a number of alkyl sulfates and non-inogenic from a number of ethoxylated alkyl phenols at their ratio 25-20: 70-75 wt.% (IV). 3. The method according to claim 1, characterized in that as (II) use a mixture of aromatic hydrocarbons that do not contain benzene, with a boiling point not exceeding 170 ° C. 4. The method according to claim 1, characterized in that as (III) use a mixture of aliphatic C ₇ -C ₉ and aromatic hydrocarbons with a content of the latter of at least 60 wt.%, Not containing benzene, with a boiling point not exceeding 170 ° FROM.

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