SU1490119A1 - Method of separating epichlorohydrine from a mixture of products of epoxidation of allyl chloride with tret-butyl hydroperoxide - Google Patents

Abstract

The invention relates to heterocyclic compounds, in particular to the isolation of epichlorohydrin from a mixture of epoxidation products of allyl chloride by tert-butyl hydroperoxide, which is used in the manufacture of epoxy resins, dyes, solvents. The goal is to improve the quality of the final product. Its isolation is carried out by extractive distillation in the presence of isopropyl benzene. After the first stage of rectification, extractive rectification is additionally carried out in the presence of propylene glycol — 1.2 at a molar ratio of propylene glycol — 1.2 - epichlorohydrin 0.25-1.0: 1. 1 tab.

Description

This invention relates to an improved process for separating epichlorohydrin from a mixture of epoxidation products of allyl chloride by tert-butyl hydroperoxide. Epichlorohydrin is used in the production of epoxy resins, dyes, solvents.

The purpose of the invention is to improve the quality of the target product.

The invention is illustrated by the following examples.

Example 1. After distillation of allyl chloride and a number of volatile components (acetone, methanol, water, formic acid) in a distillation column from the reaction mixture, the bottom product is re-evaporated to separate from heavy sludge and catalyst solution. After

this remaining mixture containing 55.86% by weight of epichlorohydrin, 33.27% by weight of tert-butyl alcohol, 3.09% by weight of allyl alcohol, 2.15% by weight of ditert-butyl peroxide, 2.07% by weight of acetic acid and 3.56% by weight of tert-butyl hydroperoxide are fed to a continuous laboratory distillation column with an efficiency of 30 t. with a speed of 90.0 ml / h (88.39 g / h). An extractant — isopropyl benzene — is introduced into the upper part of the distillation column at a rate of 150 ml / h (126.93 g / h), i.e. at a molar ratio of isopropyl benzene, the initial mixture is 1: 1. The rectification was carried out at a residual pressure in the column of 15.996 kPa (120.0 mm Hg), a bottom temperature of 80.0 ° C, a top temperature of 40.3 ° C, reflux

four

WITH

:about

3U

Including 2.0. At the top, at a rate of 44.68 ml / h (35.96 g / h), tert-butyl alcohol containing 0.68% by weight of epichlorohydrin, 7.58% by weight of allyl alcohol, 5.27% by weight of di-butyl butyl peroxide , 4.58 wt.% Acetic acid. Isopropylbenzene containing 27.37% by weight of epichlorohydrin, 0.1% by weight of acetic acid, 1.76 masses of tert-butyl hydroperoxide, at a rate of 192.57 ml / h (179.36 g / h) is withdrawn from the bottom of the column. and then subjected to rectification at P,;, 8.0 kPa (60.0 mm Hg). A distillation mixture containing 91.79% by weight of epichlorohydrin, 5.91% by weight of tert-butyl hydroperoxide was distilled off at a speed of 45.9 ml / h (53.5 g / h). O, 34% by weight of acetic acid, 1.96% by weight of isopropylbenzene. Epichlorohydrin is isolated from this mixture by extractive distillation. In accordance with the proposed method, this mixture is fed to a laboratory distillation column with a continuous effect and an efficiency of 30 v. with a speed of 130.0 ml / h (152.2 g / h). The extractant, propylene glycol, is introduced into the upper part of the columns.

., 2 with a speed of 40.0 ml / h (41.6 g / h) i.e. at the molar ratio of propylene glycol-1,2 - epichlorohydrin 0.25: 1.0. Column top pressure

5.3 kPa (40.0 mm Hg), top temperature 40.3 ° С, reflux ratio 3.0. Epichlorohydrin with a concentration of 99.5 wt.%, Containing 0.35 wt.% Acetic acid and 0.15 wt.% Tert-butyl hydroperoxide is taken in the distillate. From the bottom of the column, propylene glycol-1,2 with a concentration of 77.97% by weight, containing 16.44% by weight of hydroperoxide of tert-butyl and 5.59% by weight of isopropylbenzene, which is subjected to

are rectification at P

ost

6.7 kPa

(50.0 mm Hg) and a reflux ratio of 0.5. An azeotropic mixture containing 75.2% by weight of tert-butyl hydroperoxide and 24.8% by weight of isopropyl benzene is taken from the top of the column at 5.3 ° C, and propylene glycol-1, 2 with a concentration of 11% 99.95% by weight, which return to the column purification of epichlorohydrin from hydroperoxide tertbougle extractypical rectification.

Example 2. A mixture containing 55,86 wt.% Epichlorohydrin, 33,27 may. tert-butyl alcohol, 3.09 mA.%

from 15 20 25 30

. dz

35

50

gf

nineteen

allyl alcohol, 2.15 wt.% of di-tert-butyl cross, 2.07 wt.% of acetic acid, and 3.56 wt.% of tert-butyl hydroperoxide, are fed into a laboratory distillation column with a continuous efficiency of 30 v. at a rate of 20.0 ml / h (19.64 g / h). The extractant — isopropylbenzene is introduced into the upper part of the column at a rate of 163.6 ml / h (141.05 g / h) at 40.0 s (molar ratio, isopropylbenzene — starting mixture 5: 1). The distillation was carried out at a residual pressure in the column of 15.996 kPa (120.0 mm Hg), a cube temperature of 90.0 ° C, and a top temperature of 44.2 ° C. On top of the column at a rate of 9, 92 ml / h (7.98 g / h) take tert-butyl alcohol containing 7.59% by weight of allyl alcohol, 5.28% by weight of di-butyl-peroxide, 5.09% by weight of acetic acid. Isopropylbenzene, containing 7.18% by weight of epichlorohydrin and 0.46% by weight of tert-butyl hydroperoxide, is withdrawn from the bottom of the column at a rate of 17 ml / h (152.72 g / h) and then subjected to rectification at 8.6 kPa (60.0 mm Hg). A mixture containing 96.82% by weight of epichlorohydrin, 2.48% by weight of tert-butyl hydroperoxide and 0.7% by weight of isopropyl benzene is distilled into the distillate.

Purification of epichlorohydrin from an undesirable impurity, tert-butyl hydroperoxide, is carried out by extractive distillation in the presence of propylene glycol -1.2. In accordance with the proposed method, the initial mixture of the indicated composition is fed to a laboratory distillation column of continuous action with an efficiency of 30 t. with a speed of 100.0 ml / h (117.0 g / h). The extractant — propylene glycol — 1, 2 (the molar ratio of propylene glycol — 1,2 — epichlorohydrin 1: 1) is introduced into the top of the column at 40.0 C at a rate of 95.0 ml / h (98.8 g / h). The pressure of the top of the column is 5.3 kPa (40.0 mm Hg), the reflux ratio is 3.0. Epichlorohydrin with a concentration in wt.%, Containing 0.02 wt.% Tert-butyl hydroperoxide, is taken at a rate of 96.8 ml / h (113.3 g / h), and the bottom product containing, in addition to propylene glycol, -1 , 2 2.83% by weight of tert-butyl hydroperoxide and 0.90% by weight of isopropyl benzene are subjected to recti5

fication with ROL- (50.0 mm Hg) and a reflux ratio of 0.5. An azeotropic mixture containing 75.2% by weight of tert-butyl hydroperoxide and 24.8% by weight of isopropylbenzene is removed over the column. At the bottom of the column at 138.0 C, propylene glycol-1,2 is withdrawn and tert-butyl hydroperoxide is returned to the UI refining column of epichlorohydrin.

Example 3. This and all subsequent examples deal with the separation of the reaction mixture obtained by epoxidizing allyl chloride with tert-butyl hydroperoxide, after separating unreacted allyl chloride from it, as well as low-boiling impurities, of the catalyst solution and after separating from it the tert-butyl alcohol, allyl chloride alcohol, ditertbutyl-peroxide and acetic acid by the method of extractive distillation in the presence of isopropylbenzene, the remaining mixture contains 96.82% by weight of epichporhydrin, 2.48% by weight of hydroperoxide KazISS t-butyl, and 0.7 wt.% isopropylbenzene. Into a laboratory distillation column of continuous action with an efficiency of 30 t. at a rate of 100 ml / h (117.0 g / h), the initial mixture of the indicated composition is fed. At the top of the column at a rate of 7.0 ml / h (48.9 g / h), the extractant — propylene glycol — 1.2 (molar ratio propylene glycol — 1,2 — epichloro-hydrin 0.5: 1, 0). Reflux number 3.0 From the top of the column at a pressure of 5.2 kPa (40.0 mm Hg) and a temperature of 40.3 C at a rate of 96.8 ml / h (113.3 g / h) select epichlorohydrin with a concentration of 99 , 98 wt.%, And from the cube at 135.0 C, propylene glycol-1,2, containing 5.51 wt.% Tert-butyl hydroperoxide and 1.56 wt.% Isopropyl benzene, is withdrawn. The yield of epichlorohydrin is 99.7% of its mass in the initial mixture.

Example 4. The initial mixture of the same composition as in Example 3 was fed to a laboratory distillation column of continuous action with an efficiency of 30 t. with a speed of 100.0 ml / h (117.0 g / h). At the top of the column at 40.0 ° C, propylene glycol -1, 2 is introduced at a rate of

196

10.0 ml / h (10.4 g / h). Molar ratio prrpylene glycol-1,2 - epichlorohydrin 0.1: 1.0). Reflux number 3.0. Epichlorohydrin containing 2.29 wt.% Was removed from the top of the column at a GROWTH of 5.2 kPa (40.0 mm Hg) and at a temperature of 39.7 ° C at a rate of 90.0 ml / h (115.9 g) tert-butyl hydroperoxides, and propylene glycol-1,2, containing 7.15% by weight of isopropyl benzene and 2.18% by weight of tert-butyl hydroperoxide, was extracted from a cube at 135.0 ° C. The output of epichlorgium; 1; Rin was 99.7 wt.% From its mass in the initial mixture.

Example 5. The initial mixture of the same composition as in Example 3 is fed to a laboratory distillation column with an indispensable effect with an efficiency of 30 t. at a rate of 145.0 ml / h (150.8 g / h), the extractant — propylene glycol — 1.2 (the mole ratio of propylene glycol — 1.2 epichlorohydrin — 1.25: 1.0) is introduced. Reflux number 3.0. Top of the column at a temperature of 40.3 C and a pressure of 5.2 kPa (40.0 mm Hg) at a rate of 96.7 ml / h (113.3 g / h) select epichlorohydrin with a concentration of 99.99 wt. containing 0.01% by weight of tert-butyl hydroperoxide, and from the bottom at 140.0 ° C, propylene glycol-1.2, containing 1.88% by weight of hydro-transfer of tert-butyl and 0.53% by weight of isopropyl benzene, are diverted. The output of epichlorohydrin 99.7% of its mass in the original mixture.

The improvement in the quality of isolated epichlorohydrin compared to a known method is illustrated by the data given in the table.

Claims (1)

Invention Formula The method of separating epichlorohydrin from a mixture of chloride epoxidation products. allyl tert-butyl hydroperoxide by extractive distillation in the presence of isopropyl benzene, characterized in that, in order to improve the quality of the target product, after the first rectification stage, extractive distillation is carried out in the presence of propylene glycol -1.2 at a molar ratio of propylene glycol-1,2 - epichlorohydrin; (0,25-1,0): 1 Famous 1 (isopropyl benzene - initial mixture 1.0: 1.0) 2 (isopropyl benzene — 5: 1 initial mixture) Proposed 1 (prapylene glycol - 1,2 - epichlorohydrin 0.25: 1.0) 2 (propylene glycol - 1,2 - epichlorohydrin 1.0: 1.0) 3 (propylene glycol - - 1,2 - epichlorohydrin 0.5: 1, 4 (propylene glycol - 1,2 - epichlorohydrin 0.1:, 0) 5 (propylene glycol - 1,2 - epichlorohydrin 1.25: 1.0) Tert-butyl hydroperoxide 5.91, acetic acid 0.34, isopropyl benzene 1.96 Hydroperoxide tertbutyl 2.48; isopropyl benzene 0,7 Acetic acid 0.35, hydroperoxide of tert-butyl 0.15 Tert-butyl hydroperoxide 0.02 Tert-butyl hydroperoxide 0.02 Tert-butyl hydroperoxide 2.29 Tert-butyl hydroperoxide 0.01 Compiled by N. Kulikov Editor M. Nedoluzhenko Tekhred L. Serdyukova Proofreader I. Gorna Order 3644/27 Circulation 352 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5  ..-. "" "." "... K.Bi" .. v ,, .. Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 Corrector