RU2129114C1 - Method of preparing tertiary butyl chloride - Google Patents

Abstract

FIELD: organic synthesis, more particularly intermediate product in organic synthesis. SUBSTANCE: tertiary butyl chloride is prepared by hydrochlorination of isobutylene with hydrogen chloride in liquid phase in reactor. The latter is unit graphite shelf-type heat exchanger with reactor length to reactor cross section ratio of (375-1250): 1 at temperature from -20 C to -25 C, hydrogen chloride to isobutylene volumetric ratio of (1.03-1.05): 1, reagent feed rate of 803.9-1265 h^-1. Method makes it possible to increase yield of tertiary butyl chloride to 98.7%. EFFECT: more efficient preparation method. 1 tbl

Description

 The invention relates to the chemical industry, in particular to a method for producing tertiary butyl chloride, used as an alkylating agent in the process of obtaining additives for mineral oils, as well as to obtain a polymerization catalyst.

 A known method for producing tertiary butyl chloride is that a mixture of 50 ml of tertiary butyl alcohol and 250 ml of concentrated hydrochloric acid is shaken vigorously in a separatory funnel for 10 minutes. The organic layer was separated, dried on calcium chloride and distilled. The yield of the target product is 91.7% (Fizer L., Fizer M. Reagents for organic synthesis. -M .: Mir, 1970, p. 177).

 The disadvantage of this method is the high consumption of hydrochloric acid, a low yield of tertiary butyl chloride, the need for a drying step.

 A known method of producing tertiary butyl chloride by the interaction of tert-butyl alcohol with thionyl chloride in dimethylformamide medium, followed by washing with 5% sodium hydroxide solution and vacuum distillation (Industrial organochlorine products. Handbook edited by L.A. Oshin. -M.: Chemistry 1978, pp. 296-302).

 The disadvantage of this method is the use of toxic and corrosive active solvent and thionyl chloride and multi-stage.

 Closest to the claimed is a method of producing tertiary butyl chloride by chlorination of isobutylene in the production of a metal chloride fumigant, where tertiary butyl chloride is formed as a by-product in a small amount - 25 kg per 1 g of metal chloride (Sterlitamak, CJSC "Caustic". Standing Procedure No. 33- 89 for the production of metal chloride. Approved September 18, 89).

 The disadvantage of this method is the low yield of tertiary butyl chloride due to the fact that it is a by-product.

 The objective of the invention is to increase the yield of tertiary butyl chloride.

The essence of the invention lies in the fact that tertiary butyl chloride is obtained by hydrochlorinating isobutylene in a liquid phase in a reactor, which is a shelf-type block graphite heat exchanger with a ratio of the length of the reactor to its cross section (375-1250): 1, at a temperature of from -20 to -25 ^o C, the volumetric ratio of isobutylene: hydrogen chloride (1.03-1.05): 1, the volumetric feed rate of the reagents 803.9-1265 h ^-1 .

The speed of the process depends on the solubility of hydrogen chloride in isobutylene. It has been experimentally established that carrying out the hydrochlorination process at sub-zero temperatures leads to the fact that isobutylene reacts with hydrogen chloride instantly, i.e., the process speed increases as the reaction mass cools from -20 to -25 ^o C.

 Carrying out the process in a shelf-type block graphite heat exchanger ensures the movement of reagents in countercurrent flow over the shelves of the heat exchanger. Each shelf is a longitudinal displacement reactor. Stirring of the reaction mass occurs during overflow from shelf to shelf.

 The use of a shelf-type block graphite heat exchanger and carrying out the process at sub-zero temperatures provides intensive mixing, which leads to an increase in the yield of tertiary butyl chloride. In the process, almost complete conversion of isobutylene is achieved - 98.7%.

На выходе из реактора газообразный хлористый водород и уносимую хлорорганику в виде газа отделяют от жидких продуктов реакции и подают в конденсатор, где хлорорганика отделяется от хлористого водорода, которые не сконденсировались вместе с основным потоком.The formation of tertiary butyl chloride and as a by-product of hydrogen chloride occurs in the hydrochlorinator, since the process is carried out in excess of hydrogen chloride to achieve isobutylene conversion

At the outlet of the reactor, gaseous hydrogen chloride and entrained chlorine in the form of gas are separated from the liquid reaction products and fed to a condenser, where the organochlorine is separated from hydrogen chloride, which were not condensed together with the main stream.

 Organochlorine condensation and stripping of hydrogen chloride are carried out for stripping the dissolved hydrogen chloride in crude tert-butyl chloride and distilling off the gaseous hydrogen chloride formed during the production of tert-butyl chloride.

 Next, the absorption of hydrogen chloride by recycled water to obtain a solution of hydrochloric acid.

 Raw tert-butyl chloride, after distillation of hydrogen chloride, is fed to the distillation column to a planting column where technical tert-butyl chloride is released that meets the requirements of the standard. A stabilizer is added to the finished product - soda ash.

 Example 1

Tertiary butyl chloride is obtained by hydrochlorinating isobutylene in a liquid phase in a reactor, which is a shelf-type block graphite heat exchanger with a ratio of length to its cross section of 375: 1. 32.6 m ³ / h of liquid isobutylene and 35.7 m ³ / h of hydrogen chloride are fed countercurrently that countercurrently move along the shelves of the heat exchanger. Each shelf is a longitudinal displacement reactor. Stirring of the reaction mass occurs during flow from shelf to shelf.

Heat is removed by supplying a refrigerant that moves in the direction of movement of the reaction mixture. The hydrochlorination process is carried out at a volumetric feed rate of the reagents 1265 h ^-1 , a temperature of -10 ^o C and a ratio of hydrogen chloride and isobutylene of 1.09: 1. The yield of tertiary butyl chloride is 93.2%.

 Example 2

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of length to its cross section of 500: 1. 30.5 m ³ / h of isobutylene and 31.4 h ^-1 hydrogen chloride are fed countercurrently at a volumetric feed rate of reagents 948.6 h ^{- 1} , a temperature of -10 ^o C, the ratio of hydrogen chloride and isobutylene 1.03: 1. The yield of tertiary butyl chloride is 95.7%.

 Example 3

Analogously to example 1, isobutylene hydrochlorination is carried out in a reactor with a ratio of length to its cross section of 625: 1. 30.5 m ³ / h of isobutylene and 31.4 h ^-1 hydrogen chloride are fed countercurrently at a volumetric reagent feed rate of 677.7 h ^{- 1} , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.03: 1. The yield of tertiary butyl chloride is 97.7%.

 Example 4

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of length to its cross section of 750: 1. 45.5 m ³ / h of isobutylene and 46.3 h ^-1 hydrogen chloride are fed countercurrently at a volumetric feed rate of reagents 850 h ^-1 , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.02: 1. The yield of tertiary butyl chloride is 98.4%.

 Example 5

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a solution with a ratio of length to its cross section of 875: 1. 50.1 m ³ / h of isobutylene and 52.5 h ^-1 hydrogen chloride are fed countercurrently at a volumetric feed rate of reactants of 814.3 h ^{- 1} , a temperature of -25 ^o C, the ratio of hydrogen chloride and isobutylene is 1.05: 1. The yield of tertiary butyl chloride is 98.6%.

 Example 6

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of length to its cross section of 1000: 1. 61.4 m ³ / h of isobutylene and 63.2 h ^-1 hydrogen chloride are fed countercurrently at a volumetric flow rate of the reactants 865.3 h ^{- 1} , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.03: 1. The yield of tertiary butyl chloride is 98.7%.

 Example 7

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of length to its cross section 1125: 1. 65.1 m ³ / h of isobutylene and 67.4 h ^-1 hydrogen chloride are fed countercurrently at a volumetric flow rate of reactants 818 h ^-1 , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.04: 1. The yield of tertiary butyl chloride is 98.5%.

 Example 8

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of the length to its cross section of 1250: 1. 70.4 m ³ / h of isobutylene and 74.3 h ^-1 hydrogen chloride are fed countercurrently to the reactor at a volumetric feed rate of reagents 803.9 h ^{- 1} , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.06: 1. The yield of tertiary butyl chloride is 98.5%.

 Example 9

Analogously to example 1, the hydrochlorination of isobutylene is carried out in a reactor with a ratio of length to its cross section of 25: 1. 50.2 m ³ / h of isobutylene and 52.4 h ^-1 hydrogen chloride are fed countercurrently at a volumetric flow rate of reactants 685 h ^-1 , a temperature of -20 ^o C, the ratio of hydrogen chloride and isobutylene 1.04: 1. The yield of tertiary butyl chloride is 66.9%.

 These examples are summarized in table.

The table shows that the maximum yield of tertiary butyl chloride with a ratio of hydrogen chloride and isobutylene (1.03 - 1.05): 1 at a temperature of the process from -20 to -25 ^o C.

Claims (1)

A method of producing tertiary butyl chloride by chlorination of isobutylene with hydrogen chloride, characterized in that the chlorination is carried out in the liquid phase in a shelf-type graphite heat exchanger with a ratio of length to cross section (375 - 1250): 1, at a temperature of -20 to -25 ^o C, volume ratio of chloride hydrogen and isobutylene (1.03 - 1.05): 1.

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