SU1297721A3 - Method for producing dichlorpropanols - Google Patents

Abstract

The invention relates to halogen-containing alcohols, in particular dichloropropanol (DHP), used as intermediates in the synthesis of glycerin and epichlorohydrin glycerol. Increasing the yield and quality of DHP is achieved by changing the methods of supplying the initial reagents, their ratios and pH of the reaction medium. The preparation of DHP is carried out by treating the aqueous solution of chlorine with an aqueous solution of allyl chloride (CA) at their molar ratio (1.01-1.10) :, pH 2-5 and a temperature of 25-40 0. At the same time, aqueous solutions of Cl / ji and XA are obtained directly in the piping system for recirculating the reaction mixture containing 2 vortex pumps (HV) by supplying XA to the suction of the first HV and feeding Clj using the second VN H preferably using b arborer, connected with HH). It is advisable to maintain the pH by adding 1-57, an aqueous solution of sodium hydroxide or a solution of catholyte. The method allows to increase the yield of DHP to 97.8-99.5% and the quality of DHP (the content of trichloropropane and tetrachloro-past ethers decreases), 3 hp, f-ly, 2il. i FROM YOU

Description

1129

This invention relates to a process for the preparation of dichloropropanols, used as intermediates for the preparation of glycerin epichlorohydrin and glycerin.

The aim of the invention is to increase the yield and quality of target products by reacting an aqueous solution of chlorine and apyl chloride at a molar ratio of (1.01-1.10): 1, while maintaining a pI of 2-5 K at a temperature of 25-40 seconds and obtaining aqueous solutions of chlorine and aplil chloride directly in the piping system for recycling the reaction mass containing two vortex pumps.

Fig. 1 shows a single-jet version of the chlorhydroxylation of allyl chloride; in fig. 2-jet version ustaning chlorine-hydroxyl-silicon ir in alli chloride chloride,

In the single-jet variant (Fig. 1), the solution obtained as a result of the reaction is fed from the reactor 1 to the vortex pump 2, to the suction of which liquid aplil chloride is supplied. A solution of their vortex pump 2, fed with fresh water, enters the vortex pump 3, which is supplied with chlorine by means of a barborer 4. The solution from the vortex pump 3 is transferred to the reactor 1. From the reactor 1, the product is withdrawn by overflow 5,

In the double-jet variant (Fig. 2), the solution resulting from the reaction from reactor 1 is divided into two jets of which one is transferred to the vortex pump 2, to the suction of which liquid aplil chloride is fed, and from the vortex pump 2 with dissolved allyl chloride is returned to the reactor 1, the second jet from the reactor 1 fed with fresh water is transferred to the vortex pump 3, into which chlorine gas is fed through the bubbler 4. The solution from the vortex pump 2 is returned to the reactor i. The product from reactor 1 is diverted by overflow 5.

Example 1. In the apparatus according to FIG. 1, an aqueous solution (1.5 dm) of dichloropropanol with a concentration of 2.1 wt.% Is placed, the vortex pumps 2 and 3 are turned on and the contents of the reactor are heated to 40 C.

After the temperature has stabilized, the introduction of chlorine gas begins.

12

aplil chloride and technological medium at a rate of 1.40 mol / h, 1.27 mol / h and 6.75 dm / h, respectively. A 3% aqueous solution of NaOH was introduced into the reactor at a rate of 1.80, which maintains the pH of the reaction solution at 4.5-5. By adjusting the throttle valve on the outlet pipe from pump 2, the recirculation rate is set. 7: 1 (the ratio of the volume of circulating fluid to the volume of the product taken). The resulting product contains mmol / cm: Total chlorine 0.52 NS10,176

Organic chlorine is 0.344 which corresponds to a dichloropropanol concentration of 2.22% by weight. The yield of the process was 98.4% with respect to the distilled allyl chloride, i.e., 161.2 g / h of di-lorpropanol. At the same time, 1.6% of the by-products were obtained in the form of trichloropropane and tetrachloropropyl ethers. The content of trichloropropane was 1.2%,

Example 2 An aqueous solution of dichloropropanol with a concentration of 2.22% by weight is placed in the apparatus according to FIG. 2, the vortex pumps 2 and 3 are turned on and the contents of the reactor are heated to 40 ° C. After the temperature has stabilized, the introduction of gaseous chlorine, allyl chloride and the process medium is started at a rate of 1.29 mol / h, 1.27 mol / h, and 6.1, respectively, the pH of the reaction solution was podcerta equal to 2 by introducing at a rate of 1.41 dm / h into the reactor a solution of catholyte containing 3.3% NaON and 5 , 31% NaCl,

The recirculation rate of the reaction solution is 7: 1.

The resulting product contains mmol / cm:

Total chlorine 0.640

HC10,314

Organic

chlorine0,326

which corresponds to the concentration of dichloropropanol 2.1 wt.%.

The process was 98.2% relative to the allyl chloride used, t, e, 160.9 g / h of dichloropropanol. At the same time, 1.8% of the by-products were obtained in the form of trichloropropane and TetraPropropyl

esters, the content of trichloropropane was .1.4%,

Example 3. In an apparatus according to FIG. 1, filled with a solution with a composition, mmol / cm: total chlorine 0.502; HC1 0.168; organic chlorine, 0.334; at a rate of 1.21 mol / h; chlorine, at a rate of 1.17 mol / h; allyl chloride, at a rate of 1; process water, at a rate of 1.57 1% aqueous solution of NaOH. The preservation of these parameters and a temperature of 32 C contributes to the fact that

The pH of the reaction medium is 2.1. Poe

(ABOUT

Total chlorine 0,577

HC10,193

Organic

chlorine 0.384

Active chlorine 0.003 The yield of the process, calculated as in Example 1, was 97.8 mol%, which is 136.3 g / h of dichloropropanols. At the same time, 2.2% of by-products were obtained, including 1.7% trichloropropane.

Thus, the proposed method allows to increase the yield of dichloropropol to 97.8-99.5% and the irradiated product shakes them, contains mmol / cm:) 5 in, since the content of by-products of trichloropropane and tetrachloropropyl ethers decreases in the target product .

Total chlorine 0,502

HC10,168

Organic chlorine 0.334

Process output counted as

Claims (4)

1. A method of producing dichloropropanol by reacting an aqueous solution of allyl chloride with an aqueous solution of chlorine introduced into the reaction system using pumps, which includes recycling the reaction mass and neutralizing the resulting hydrogen chloride, which is 30 in order to increase the yield and quality of the target products , aqueous solutions of chlorine and allyl chloride are obtained directly in the piping system for recirculation - 35 of the reaction mixture containing two vortex pumps, by feeding allyl chloride to Primarily for the suction of the first recirculation vortex pump and the supply of chlorine with the output of the process, counted as 40 using the second recirculation vortex Chlorine Chloride Allyl Technological water 5% water NaOH solution pH of the reaction medium is 2.0. The resulting product contains mmol / cm: Total chlorine HC1 7.56 0.84 0.420 0.141 Organic chlorine 0.279 in example 1, it was 99.5% mol, which gives 163 g / h of dihporpropanolov. Example 5. In the equipment for fng. 2, a water solution of dichloropropanol with a concentration of 2.47 wt.% And a HCl concentration of 0.193 mmol / cm is placed. The process is carried out at. The following feeds are continuously served: 1.10 mol / h 50 1.08 mol / h Chlorine Allyl chloride. Water technology Catholyte solution with a content of 3% and 4.8% As a result of the reaction, a product is obtained with a content, mmol / cm: 3.95 1.39 dm / h 55 Total chlorine 0,577 HC10,193 Organic chlorine 0.384 Active chlorine 0.003 The yield of the process, calculated as in Example 1, was 97.8 mol%, which is 136.3 g / h of dichloropropanols. At the same time, 2.2% of by-products were obtained, including 1.7% trichloropropane. Thus, the proposed method allows to increase the yield of dichloropropol to 97.8-99.5% and shakes them, since the content of by-products of trichloropropane and tetrachloropropyl ethers is reduced in the target product. 1. A method of producing dichloropropanol by reacting an aqueous solution of allyl chloride with an aqueous solution of chlorine introduced into the reaction system using pumps, which includes recycling the reaction mass and neutralizing the resulting hydrogen chloride, which is different in order to increase the yield and quality of the target products , aqueous solutions of chlorine and allyl chloride are obtained directly in the piping system for recycling - 5 of the reaction mass containing two vortex pumps, by feeding allyl chloride without directly to the suction of the first recirculation vortex pump and the supply of chlorine with the aid of the second recirculation flow 0 The pump is pumped and the reaction is carried out at a molar ratio of chlorine and allyl chloride (1.01-1.10): while maintaining the pH of the reaction mass 5 to be 2-5 and the temperature is 25-40 C. 2. A method according to claim 1, differing from that by supplying chlorine with a bubbler connected to a second vortex pump. 3. The method according to claim 1, about t l and h a - y and with the fact that the pH of the reaction mass is maintained by adding 1-5% of its aqueous sodium hydroxide solution. 4. The method according to claim I, characterized in that the pH of the reaction mass is maintained by adding a solution of catholyte. five 0U8.i Fal2 Editor M, Kelemesh Compiled by N. Kapitanova Tehred M. Khodanych Order 800/64 Circulation 372 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, 4/5 Production and printing company, Uzhgorod, st. Project, 4 . Proofreader M. Sambors.ka Subscription