WO2011058575A1

WO2011058575A1 - An improved process for the preparation of 2,3,-dichloro 1,3,butadiene from 1,3 butadiene

Info

Publication number: WO2011058575A1
Application number: PCT/IN2010/000227
Authority: WO
Inventors: Madhukar Balvantray Parekh
Original assignee: Pidilite Industries Ltd
Priority date: 2009-11-10
Filing date: 2010-04-07
Publication date: 2011-05-19

Abstract

The present invention relates to an improved process for the production of 2,3-Dichloro 1,3-Butadiene which comprises Chlorinating Butadiene, in liquid phase, in the presence of chlorinated solvents & phase transfer catalyst, Distilling the solvent, Distilling the formed 3,4-dichlorobutene-1, 1,4-dichlorobutene-2; and 1,2,3,4-Tetrachlorbutane; under reduced pressure,chlorinating the separated 3,4-dichlorobutene-1 and 1,4-dichlorobutene-2 to give 1,2,3,4-Tetrachlorobutane.,double Dehydrochlorinating the 1,2,3,4-Tetrachlorobutane using methanol,alkali and inhibitors under atmosphere of 1% oxides of nitrogen in nitrogen atmosphere the total period of Dehydrochlorinating being in the range of 15-33 hours to give 2,3-Dichloro 1,3-Butadiene and separating methanol to get 2,3-Dichloro 1,3-Butadiene

Description

An improved process for the production of 2,3-Dichloro 1,3- Butadiene from 1,3-Butadiene

• Field of invention:

The present invention relates to an improved process for the production of 2,3-Dichloro 1,3-Butadiene from 1,3-Butadiene. The process of the present invention is particularly useful for the preparation of 2,3-Dichloro 1,3-Butadiene using liquid phase chlorination. The 2,3-Dichloro 1,3-Butadiene prepared by the process of the present invention is useful for the manufacture of polychloroprene rubber.

• Background _Qf invention:

2,3-Dichloro 1,3-Butadiene is used as comonomer with chloroprene in the manufacture of polychloroprene rubber 2,3-Dichloro 1 ,3-Butadiene can be prepared from starting materials like 1 ,2,3,4 Tetrachlorobutane, 2,3,4 -trichlorobutane which in turn can be produced by using 1,4- dichlorobutene-2, 1,3-dichlorobutene-2. Starting material for all these compounds is 1,3-Butadiene.

• Prior art

Chlorination of 1,3-Butadiene to yield 3,4-dichlorobutne-1 and 1,4-dichlorobutene-2 is well known process. These Chlorinations are done in vapor phase without catalyst at very high temperature ranging from 200-280 Deg.C. 1,2,3,4-tetrachlorobutane is produced from S^-dichJorobutne- ahd†;^- dichlorobutene-2 by further chlorination. Then, the 2,3-Dichloro 1 ,3-Butadiene is produced from 1,2,3,4-Tetrachlorobutane by dehydrochlorination using Sodium hydroxide solution or any other alkali. Commercially chlorination of Butadiene is done in vapor phase for the production of chloroprene and 2,3-Dichloro 1,3-Butadiene.

United States Patent number 4049729 describes a process of chlorinating butadiene in the vapor phase using a molar ratio of butadiene to chlorine of from 5:1 to 50:1 and preferably from 8:1 to 30:1 at from 70° to 250° C, separating the thus formed dichlorobutenes from the unreacted butadiene by condensing them in a scrubber-cooler wherein the heat required to vaporize the makeup liquid butadiene feed stream is provided by the condensing dichlorobutenes.

United States Patent 4233252 describes an improved process for the continuous chlorination in vapor phase of butadiene to a mixture of dichlorobutenes at a temperature about 90^o-250° C, wherein chlorine is premixed with a portion of butadiene and introduced at one end of a tubular reactor,, while the remainder of the butadiene, which is used in a large excess, is introduced at one or more points downstream from the point of introduction of the chlorine-butadiene mixture, the temperature and volume of this additional butadiene being sufficient to effectively cool the reacting mixture so that the maximum temperature in the reactor does not exceed about 250° C. but does not fall downstream from the butadiene injection point below about 130° C.

For liquid phase chlorination of butadiene some earlier work is given in GB 8016493. It describes the process of manufacture of Dichlorobutenes by feeding chlorine and Butadiene in a solution of Benzonitrile containing copper chloride. Yield is in the range of 85-90%. and byproducts like tar are not formed.

US patent no. 1435826 describes a liquid phase process of producing dichlorobutenes using carbon tetrachloride, hexane , isooctane as solvent.

US Patent no. 90121834 describes a liquid phase process in which chlorine and Butadiene are fed continuously in solvent like pentane, butane or fluorinated solvent in a oxygen free atmosphere. German Patent number GB 1413548 describes a liquid phase reaction in chlorinated organic solvents like 1,4-Dichlorobutene and /or 3,4-dichlorobutene-1

Patent no. GB 1414111 describes a liquid phase chlorination process using chlorinated organic solvents like 1,4-Dichlorobutene and /or 3,4-dichlorobutene-1 containing iron chloride, nickel chloride or cobalt chloride as catalyst.

For all the above described liquid phase processes, subsequent distillation of solvent is required. In addition large excess of solvent is required. So large facilities i.e. big equipments and high energy are required for solvent distillation. Also bye product such as tar formation is there thereby reducing the yield .

The Vapor phase chlorinations employ large excess of Butadiene. So large equipments are required for recycling Butadiene gas . Also a temperature in the range of 200-300 Deg.C is required for all kind of vapor phase reaction

There is need for improved process in terms of reduction in volume, with minimum energy requirement, low temperature namely, in the range of 40-100 Deg.C which will be more safer than high temperature and less formation of bye products such as tar and higher yield namely in the range of 80-90 %.. Liquid phase chlorination of Butadiene gives additional safety due to the use of solvent for exothermic reaction. Since chlorination is an exothermic reaction, there is possibility of runaway reaction, i.e. sudden rise of temperature , which may lead to hazardous condition. • Objectives of the invention

Therefore the main objective of the present invention is to provide an improved process for the production of 2,3-Dichloro 1 ,3- Butadiene from 1 ,3-Butadiene overcoming the drawbacks of the hitherto known processes

Another objective of the present invention is to provide an improved process for the production of 2,3- Dichloro 1,3- Butadiene from 1,3-Butadiene by liquid phase chlorination of butadiene in the presence of chlorinated solvents and phase transfer catalyst

Yet another objective of the present invention is to provide an improved process for, the production of 2,3-Dichloro 1,3- Butadiene from 1 ,3-Butadiene with minimum energy requirement, low temperature namely, in the range of 40-100 Deg.C which process will be more safer

Still another objective of the present invention is to provide an improved process for the production of 2,3-Dichloro 1 ,3- Butadiene from 1 ,3-Butadiene with less formation of bye products such as tar

Still another objective of the present invention is to provide an improved process for the production of 2,3-Dichloro 1 ,3- Butadiene from 1 ,3-Butadiene with higher yield namely in the range of 60-90%

We have observed due to our sustained R & D that chlorination of Butadiene can be carried out in liquid phase in the presence of solvents .which are chlorinated compounds, such as carbon tetra chloride, trichloromethane among others & phase transfer catalyst . The solvent distillation is done at atmospheric pressure. This chlorination gives 3,4-dichlorobutene-1 , 1 ,4-dichlorobutene-2 and 1 ,2,3,4- Tetrachlorobutane. These products are separated by distillation. 3,4-dichlorobutene-1 and 1 ,4- dichlorabutene-2 are further chlorinated to give 1 ,2,3,4-tetrachlorobutane. Chlorination of 1,4 dichlorobutene-2 is done by feeding chlorine gas at temperature in the range' of 65-75 Deg.C. Dehydrochlorination of 1 ,2,3,4 -Tetrachlorobutane is done using methanol as solvent and alkali like Sodium hydroxide or potassium hydroxide solution. Treatment with alkali solution is done during a period in the range of 1-3 hr for three times, which yields 2,3-Dichloro 1 ,3-Butadiene. Methanol forms azeotrope with 2,3-Dichloro 1 ,3-Butadiene which has low boiling point than methanol. Separating by distilling the 2,3-Dichloro 1,3-Butadiene along with Methanol intermittently in the duration in the range of 4-8 hours after each alkali addition. Total period of reaction being in the range of 15-33 hours. Then methanol is separated by extraction with alkali like Sodium hydroxide or potassium hydroxide at low temperature in the range of -10 to -20 deg.C. Such process is generally carried out at atmospheric pressure. • Summary of invention

Accordingly, the present invention provides an improved process for the production of 2,3-Dichloro ,3-Butadiene which comprises

i. Chlorinating Butadiene , in liquid phase , in the presence of chlorinated solvents & phase transfer catalyst , the solvent to Butadiene ratio used being between 10:1 to 25: 1 , the concentration of Butadiene in the chlorinated solvent being in the range of 3-5%. , the amount of phase transfer catalyst used being in the range of 0.2-0.5 weight % of total mass , at a temperature in the range of 20 to 65 deg. C to give 3,4-dichlorobutene-l , 1 ,4-dichlorobutene-2 and 1 ,2,3,4- Tetrachlorbutane;

ii. Distilling the solvent at atmospheric pressure .

iii. Distilling the formed 3,4-dichlorobutene-l , 1,4-dichlorobutene-2; and 1,2,3,4- Tetrachlorbutane; under reduced pressure in the range of 100-150 mm Hg; in such a way that 3,4- dichlorobutene-1 and 1,4-dichlorobutene-2 being separated as the top product of distillation column & 1 ,2,3,4 tetrachlorobutane being separated as the bottom product

iv. Chlorinating the separated 3,4-dichlorobutene-l and 1 ,4-dichlorobutene-2 at a temperature in the range of 65 to 75 Deg C using chlorine gas to give 1,2,3,4-Tetrachlorobutane.

v. Mixing the 1 ,2,3,4-Tetrachlorobutane obtained in step(iii) & that obtained in step(iv) .

vi. Double Dehydrochlorinating the mixed 1 ,2,3,4-Tetrachlorobutane obtained in step (v) using methanol as a solvent .alkali like Sodium hydroxide or potassium hydroxide and inhibitors under atmosphere of 1% oxides of nitrogen in nitrogen atmosphere at a temperature in the range of 50-100 Deg.C, the alkali being added to 1 ,2,3,4-Tetrachlorobutane in Methanol during a period ranging from 1-3 hours , in three stages , after an interval in the range of 4 to 8 hrs, distilling after each addition of the alkali, to minimize formation of bye product like tar, the total period of Dehydrochlorinating being in the range of 15-33 hours to give 2,3-Dichloro 1 ,3-Butadiene and

vii. Separating methanol by extraction with alkali like Sodium hydroxide or potassium hydroxide at a temperature in the range of - 0 to -20 deg.C. to get 2,3-Dichloro 1,3-Butadiene

The chlorinated solvents used in step (i) is selected from carbon tetra chloride, trichloromethane, chloroform among others. The phase transfer catalysts used is selected from quaternary ammonium compounds . Dissolved butadiene in solvent varies with the temperature & amount of butadiene which will remain in liquid phase.

The Inhibitors such as piperazine, tertiary butyl catechol(TBC) may be used in step (vi) for controlling the homopolymerization of the product Detailed Description of Invention

Exothermicity of reaction is absorbed by solvent i.e. heat evolved during reaction is absorbed by the solvent. The apparatus used for the process consists of ( A ) chlorinator reactor vessel which is a pressure vessel equipped with agitator .sparger , temperature measurement & vent condenser fitted on top, (B) a distillation set up consisting of glass flasks fitted with multinecked cover having agitator, reflux column .condenser , electric heating oil bath & suitable drains & sample tappings , (C) Set up for carrying out Dehydrochlorination reaction essentially similar to the distillation set up with additional provision for withdrawl of the final product in chilled state.

The chlorination reaction of Butadiene in step (i) is generally carried out at atmospheric pressure. To minimize the vent losses of solvent like carbon tetrachloride and other chlorinating solvent, vent condenser on the chlorinator is useful. The flow rate of chlorine is controlled such that the reaction proceeds at desired rate at which temperature of reaction remains constant in the range eliminating any losses of chlorine from the reactor system.

The solvent distillation in step (i) is essentially atmospheric in which the solvent is recovered fully which can be recycled for the further chlorination batches.

CI CH₂ CH = CH-CHzCI + CI₂ ^► CICH₂CICH CICH CH₂CI

As shown in above reaction scheme, 1 mole of 1,4 dichlorobutene-2 s reacted with 1 mole of chlorine gas to form 1 mole of ,2,3,4-Tetrachlorobutane. Temperature of reaction is maintained between 65 to 75 Deg.C. Double dehydrochlorination i.e. two times dehydrochlorination of 1 ,2,3,4 Tetrachlorobutane to 2,3- Dichloro1,3-Butadiene is effected by using alkali in Methanol under 1% oxides of nitrogen in nitrogen atmosphere. Inhibitors like tertiary butyl catechol(TBC), Phenothiazine etc. & catalysts are utilized to promote reaction & control polymerization of the product obtained. Addition of inhibitors is essential to inhibit the polymerization. The concentration of alkali used is critical to the process & essentially excess quantities are used.

2,3-Dichloro1,3-Butadiene along with Methanol is distilled at the top of distillation column. This distillation is effected at atmospheric pressure . 2,3-Dichloro1,3-Butadiene was separated from Methanol by extraction with Sodium hydroxide solution at a temperature in the range of -10 to -20 Deg.C. Spent solution can be treated suitably for recovery of valuable products like Sodium chloride, Sodium hydroxide, Methanol etc. as well as to reduce treatment costs. CICH₂CICH CICH CH₂CI + 2 NaOH MfiQH_→ CH₂= CCI-CCI » iEH₂ + 2 NaCI

(2,3-d :W ribtHitadiene)

As shown in above scheme, 1 mole of 1 ,2,3,4-TetrachloY6butane is reacted with 2 moles of Sodium hydroxide in presence of Methanol to give 1 mole of 2,3-Dichloro 1,3-Butadiene and 2 moles of Sodium chloride. Since reaction of Tetrachlorobutane is with 2 moles of Sodium Hydroxide, it is called double dehydrochlorination. Temperature of reaction is maintained between 60-70 Deg.C.

The process is described in detail in the Example given below which jj|| ven to¾s¾¾ite the ihven¾oh only and therefore should not be construed to limit the ^S5P^? °f the invention

(Example 1

25 L of Carbon tetrachloride was taken into a reactor under coofiiftf & butadiene was fed by sparger through liquid at 15 Deg.C temperature.. Solvent to Butadiene mass ratio was kept at 19. 2 KG of Butadiene dissolved in Solvent was used . 3 KG of Chlorine was added . During the addition temperature was kept at 50 Deg.C. Then the contents were cooled to room temperature & taken up for separation.

The reaction mass was then separated from the solvent by atmospheric distillatio^¾¾¾ Dichlorobutene-1 and 1,4 Dichlorobutene-2 were separated by vacuum distillation from 1,2,3,4- Tetrachlorobutane at reduced pressure of 100 mm Hg. Separated 1,4 Dichlorobutene-2 was then subjected to further chlorination to obtain 1,2,3,4-Tetrachlorobutahe as required. This Tetrachlorobutane was mixed with Tetrachlorobutane which was obtained in the earlier step. 1,2,3,4- Tetrachlorobutane then dehydrochlorinated with Sodium hydroxide in Methanol under inert atmosphere of 1% oxides of nitrogen in nitrogen. Tertiary butyl. catechol(TBC) as a inhibitor was added 65 ppm to the collection vessel to prevent homopolymerization of the product. Sodium hydroxide solution was added in three stages . Each stage of sodium hydroxide addition was effected during a period of 1 hour and each stage of distillation was done during a period of 6 hours. Total period of reaction was 21 hrs. During the reaction 2,3-Dichloro 1 ,3-Butadiene along with Methanol were distilled from the top of distillation column. Then 2,3-Dichloro 1,3-Butadierrfe was separated from Methanol by extraction with Sodium hydroxide solution at -15 Deg.C. product 2,3-

Dichloro 1,3-Butadiene of more than 99% purity and having yield of 3.6 Kg was d ied

Example 2

20. L of Carbon tetrachloride was taken into a reactor under cooling butadiene was fed by sparger through liquid at 15 Deg.C temperature. Solvent to Butadiene mass ratio was kept at 19. Butadiene dissolved around 1.6 Kg. Chlorine was added is in an amount of in the range of 2.4 Kg. During addition temperature is kept in the range of 60 Deg.C . Then the contents are cooled to room temperature & taken up for separation. The reaction mass was then separated from solvent by atmospheric distillation. 3,4 Dichlorobutene-1 and 1,4 Dichlorobutene-2 were separated by vacuum distillation from 1 ,2,3,4-Tetrachlorobutane at reduced pressure of 100 mm Hg. Separated 1,4 Dichlorobutene-2 was then subjected to further chlorination to obtain 1 ,2,3,4-Tetrachlorobutane as required. Tetrachlorobutane was mixed with Tetrachlorobutane which was obtained in the earlier step. 1 ,2,3,4-Tetrachlorobutane . then dehydrochlorinated with Sodium hydroxide in Methanol under inert atmosphere of 1% nitric oxide in nitrogen. 2-hydroxy ethyl piperazine as inhibitor was added 50 ppm to the collection vessel to prevent homopolymerization of the product. Sodium hydroxide solution was added in three stages during reaction at the temperature of 55 Deg.C and distillation is intermittent. Each stage of sodium hydroxide addition is 2 hour and each stage of distillation was 8 hours. During the reaction 2,3-Dichloro 1 ,3- Butadiene along with Methanol was distilled from the top of distillation column. Total period of reaction was 30 hrs. Then 2,3-Dichloro 1 ,3-Butadiene was separated from Methanol by extraction with Sodium hydroxide solution at -15 Deg.C. Thus final product 2,3-Dichloro 1,3-Butadiene of more than 99% purity and having yield of 2.4 Kg was separated. Advantages of the invention

• The process of the present invention is safer than high temperature vapor phase chlorination.

• Optimum amount of solvent like carbon tetrachloride can be used so that energy requirement is minimum, thereby making the process cheaper

· . The process has higher yield in the range of 60-90% and lower by-product like tar formation.

_• The process requires simple set up like pressure reactor rather than specially designed vapor phase chlorination reactor.

_• Dehydrochlorination process is done in inert atmosphere of 1% oxides of nitrogen in nitrogen.

This reduces unwanted polymer formation during the process.

Claims

We Claim

1 An improved process for the production of 2,3-Dichloro 1 ,3-Butadiene which comprises

(i) Chlorinating Butadiene , in liquid phase , in the presence of chlorinated solvents & phase transfer catalyst , the solvent to Butadiene ratio used being between 10:1 to 25:1, the concentration of Butadiene in the chlorinated solvent being in the range of 3-5%. , the amount of phase transfer catalyst used being in the range of 0.2-0.5 weight % of total mass , at a temperature in the range of 20 to 65 deg. C to give 3,4-dichlorobutene-1 , 1,4-dichlorobutene-2 and 1 ,2,3,4-Tetrachlorbutane;

(ii) Distilling the solvent at atmospheric pressure .

(iii) Distilling the formed 3,4-dichlorobutene-1 , 1 ,4-dichlorobutene-2; Jand i^^^-Tetrachlorbutane; under reduced pressure in the range of 100-150 mm Hg; in such a way that 3,4-dichlorobutene-1 and

1,4-dichlorobutene-2 being separated as the top product of distillation column & 1 ,2,3,4 tetrachlorobutane being separated as the bottom product

(iv) Chlorinating the separated 3,4-dichlorobutene-l and 1 ,4-dichlorobutene-2 at a temperature in the range of 65 to 75 Deg C using chlorine gas to give 1,2,3,4-Tetrachlorobutane.

(v) Mixing the 1 ,2,3,4-Tetrachlorobutane obtained in step(iii) & that obtained in step(iv) .

(vi) Double Dehydrochlorinating the mixed 1,2,3,4-Tetrachlorobutane obtained in step (v). using methanol as a solvent .alkali like Sodium hydroxide or potassium hydroxide and inhibitors^' under atmosphere of 1% oxides of nitrogen in nitrogen atmosphere at a temperature in the range of 50- 100 Deg. C, the alkali being added to 1,2,3,4-Tetrachlorobutane in Methanol during a period ranging from 1-3 hours , in three stages , after an interval in the range of 4 to 8 hrs, distilling after each addition of the alkali, to minimize formation of bye product like tar, the total period of Dehydrochlorinating being in the range of 15-33 hours to give 2,3-Dichloro 1,3-Butadiene and

(vii) Separating methanol by extraction with alkali like Sodium hydroxide or potassium hydroxide at a temperature in the range of -10 to -20 deg.C. to get 2,3-Dichloro 1 ,3-Butadiene

2. An improved process as claimed in claiml wherein the chlorinated solvents such as carbon tetra chloride, trichloromethane, chloroform and the like is used in step (i)

3. An improved process as claimed in claimsl & 2 wherein the phase transfer catalysts such as quaternary ammonium compounds is used in step (i) .

4. An improved process as claimed in claimsl to 3 wherein the step of adding alkali solution in step(vi) is effected in three stages , the total period of reaction being in the range of 21 to 30 hours^, and the addition of the alkali solution is effected three times , during a period of 1 hour distilling at each stage of addition in the interval of 4-8 hours