Dichloroethane production process

FIELD: petrochemical and industrial organic synthesis.

SUBSTANCE: process comprises separating gaseous pyrolysis products to recover ethylene-containing fraction with 54-65% ethylene content and C3-C5-hydrocarbon fraction. Ethylene-containing fraction is subjected to liquid-phase catalytic chlorination. Gas phase of chlorination product is purified via adsorption and fed into furnace as fuel. C3-C5-Hydrocarbon fraction is subjected to exhaustive hydrogenation, hydrogenation product is combined with fresh raw material at weight ratio (0.05ч1):1 and sent to pyrolysis plant.

EFFECT: achieved integration of process, increased reliability thereof, and reduced expenses.

1 dwg, 1 tbl, 15 ex

 

The invention relates to the petrochemical industry and, more specifically, to a method for producing 1,2-dichloroethane from the gaseous products of pyrolysis.

1,2-dichloroethane (EDC) - raw material for production of vinyl chloride, also finds use as an intermediate in the synthesis of various organic compounds and solvents for special purposes.

A method of obtaining EDC direct liquid-phase catalytic chlorination of ethylene, obtained by pyrolysis of hydrocarbons in a tubular furnace (Patent USSR No. 1396960, class C 07 C 19/045, 15.05.88) [1]. In accordance with this method to obtain dichloroethane use ethylene of a purity close to 100%.

To get out of the pyrogas ethylene concentrations required site hydrogenation of acetylene and level cold temperature -98°and, therefore, require the installation of costly ethylene refrigeration cycle. In addition, when the chlorination of concentrated ethylene flowing with the release of a large amount of heat, require more intensive heat removal. The application of this method of obtaining EDC is associated with a number of additional nodes, high flow cold low negative temperatures, i.e. with increased material and energy costs.

Also known is a method of obtaining EDC from the gaseous products of the crack the nga, including the cracking of gaseous hydrocarbons, primarily ethane (international application W0026164, 11.05.2000) [2]. The mixture of cracking products is subjected to liquid-phase chlorination in the presence of catalytic complex FeCl3and LiCl. He came into the reaction of ethane and allocate recyclist on stage cracking.

In accordance with the method [2] the products of the cracking of hydrocarbons containing ethylene, without prior separation serves to chlorination. These products, in addition to hydrogen, carbon oxides and methane, does not interfere with the chlorination of ethylene, also contain unsaturated hydrocarbons With3-C6and aromatic hydrocarbons - From6-C7that under the reaction conditions also glorious, resulting in the contamination of EDC and increased consumption of chlorine. During pyrolysis of ethane concentration of unsaturated and aromatic hydrocarbons is, wt.%:

With3H6+C3H4- 1,3
With4H6+C4H8- 1,4
C5-7(olefins and aromatics)- 0,7

During pyrolysis of raw materials that are heavier than ethane, the concentration of these components is much higher and, therefore, the chlorine consumption will be more. In addition, high energy costs require is raised to separate the impurities chlorohydrocarbons, which are formed from unsaturated and aromatic hydrocarbon impurities in ethylene.

In another known method, EDC receive liquid-phase catalytic chlorination fraction containing from 5 to 30 wt.% of ethylene. This fraction is obtained from the products of pyrolysis gasoline (Patent of great Britain No. 1096594, CL 2, 31.03.1965) [3]. Pyrolysis gasoline lead in the current high-temperature coolant obtained by the combustion of oxygen-bearing gas or methane at temperatures of ˜ 1800-1300°C. In this process, the concentration of ethylene is mainly 8-15%, moreover, along with ethylene, in equimolar ratio of acetylene is formed.

To obtain atlantageorgia fraction above the concentration of pyrolysis products remove hydrocarbons From3+and the fraction of hydrocarbon, C1-C2clear of acetylene and water. Cleared thus Atlanterra fraction, in which in addition to ethylene also contains methane, oxides of carbon and hydrogen, is subjected to chlorination in the liquid phase in the environment of EDC in the presence of FeCl3.

In the method, in accordance with [3], provides for mandatory clearing atlantageorgia faction intended to obtain EDC, from acetylene. From the technical literature it is known that the removal of acetylene can be done is manage or by hydrogenation with hydrogen, in atlantageorgia faction, or absorption. In the first case, the required additional reactor site and the site for drainage atlantageorgia fraction of water formed by the interaction of carbon oxides with hydrogen in the hydrogenation reactor. When using absorption purification of acetylene requires additional site, including trehkolonnom system of absorption-desorption.

A feature of this method is the low yield of EDC on the downloaded raw materials (gasoline)not exceeding 60%, due to low yield of ethylene in the pyrolysis gasoline in a current of superheated coolant (Vintoniv, Asclepius. The production of acetylene, M.: Chemistry, 1970, p.102-104) [4].

Certain inconveniences creates a limit to the concentration of ethylene in atlantageorgia fractions up to 30%, is used to obtain EDC since it leads to a marked reduction in performance of equipment and, consequently, to increasing energy and material costs per tonne of saleable product.

The present invention is to create a comprehensive, more technological and economical method of producing dichloroethane from the gaseous products of pyrolysis.

The objective is formulated, in accordance with the present invention, is solved due to the fact that in the method of producing dichloroethane from the gaseous product is in the pyrolysis of hydrocarbons, including the pyrolysis of hydrocarbons, the separation of the pyrolysis products with the release atlantageorgia faction and its subsequent liquid-phase catalytic chlorination, the pyrolysis is carried out in a tubular furnace, the gaseous products of pyrolysis allocate Atlanterra fraction with a concentration of ethylene 54-65 wt.%, additionally allocate a fraction of the hydrocarbon, C-3-C5, which is subjected to exhaustive hydrogenation, the hydrogenation product is mixed with fresh feedstock mass ratio of 0.05 to 1:1 and sent for pyrolysis, and gas phase products from the chlorination is subjected to adsorption treatment and sent to the pyrolysis furnace as fuel.

The invention is illustrated in the drawing, which shows a schematic diagram of an installation for implementing the method.

The installation includes a tubular furnace P-1, the reactors R-1 and R-2, heat exchangers T-1, T-2, T-3, T-4, T-5,T-6, T-7, T-8 and T-9, column K-1, K-2, K-3, K-4 and K-5, the compressor COMP-1, the desiccant-1, adsorber a-1, throttle, ETC, capacity, E-1, E-3 and E-4, the separators E-2 and E-5, the pump H-1 and H-2, as well as pipelines and processing flows 1-41.

Fresh raw stream 1 in a mixture with gidrirovannoe fraction With3-C5thread 30, sent in a tube furnace pyrolysis of P-1. The products of pyrolysis stream 2 from the furnace P-1 is cooled by evaporation of condense the and 4 in the heat exchanger T-1 to form a pair 5. Emerging from the heat exchanger T-1 products of pyrolysis - sin 3 cool part of the circulating heavy liquid fuel 7 - kubovy product column K-1. The resulting mixture 6 - sin circulating heavy liquid fuel is injected into the column K-1, where sin is cooled by the flow of liquid products of pyrolysis - pyrolysis condensate fraction 10 and a part of the circulating heavy liquid fuel 9. From the cube K-1 column output a stream of hot circulating heavy liquid fuel, then cooled in the heat exchanger T-2. After the heat exchanger T-2 stream is cooled circulating heavy liquid fuel is divided into three parts - the surplus of heavy fuel oil from the total flow through the pipeline 8 is removed from the system, another part of the thread 9 return in column K-1 and third - stream 7 serves to mix with sin. From the top of column K-1 take away the sin 11, sent forth in the column K-2, where it is additionally cooled by water supplied through the pipeline 16. From the cube K-2 column display a mixture of water and pyrolysis condensate fraction stream 12 is directed further to the stratification in the tank E-1. The pyrolysis condensate fraction 13 from the tank E-1 serves to pump H-1. After pump N-1 stream 13 is divided into two parts. One part of the thread 10 is directed to the irrigation columns K-1 and the other excess pyrolysis condensate fraction through the pipeline 14 is removed from the system. The flow of water from the tank E-1 serves to pump H-2. Stream after the pump N2 is divided into two parts, one of which is directed to the cooling in the heat exchanger T-3 and then as stream 16 for irrigation K-2 column, the other an excess of water in the pipelines 75 is removed from the system. Cooled to 25-35°With the flow of pyrogas 17 is compressed in the compressor COMP-1. Compressed to ˜ 4.0 MPa flow pyrogas is directed for cooling in the heat exchanger system T-4. The cooled gas stream is separated in separator S-2. The liquid phase from the separator S-2, which is a mixture of water and fraction5-C7via the pipeline 18 is directed into the tank E-1 on the bundle. The gas phase from the separator S-2, line 19 is introduced into the desiccant 0-1. Dry flow pyrogas 19 of desiccant 0-1 send in column K-3.

From the top of column K-3 through the pipeline 20 output vapor-gas mixture, which is subjected to speed cooling in the heat exchangers T-5, T-6 and T-7. In the heat exchanger T-5 stream is cooled to a temperature of -(26-32)°C. Leaving the heat exchanger T-5 the flow is directed into the heat exchanger T-6, where it is cooled to a temperature of -(30-34)°stream 22 having a temperature of ˜ -70°C. withdrawing from the T-6 stream is cooled in the heat exchanger T-7 to temperature(40-43)°S. In this part of the component condenses to a liquid. Gas-liquid stream 21 is directed into the tank E-3 bundle. The flow of liquid from the tank E-3 through the pipe 23 serves to irrigate the K-3. the gas phase from the tank E-3 - stream 22 is passed through the throttle, ETC to reduce the pressure to 0.7-0.9 MPa. However, due to throttling, stream 22 is cooled to -(66-73)°C. the Cooled stream 22 is directed into the heat exchanger T-6, which due to heat exchange with the flow of the cooled stream 20. Target product stage pyrolysis - Atlanterra faction, away from the heat exchanger T-6 to line 24.

CBM product column K-3, which is a fraction of hydrocarbons With3-C5via the pipeline 25 is directed to mixing with providerone fraction With3-C5and hydrogen streams 29 and 39, respectively. Mixed gas-liquid stream 26 hydronaut in the reactor R-1. The 27 hydrogenation product from the reactor R-1 is cooled in the heat exchanger T-8, the cooled stream is separated in the separator E-4. The liquid phase through the pipeline 28 is sent to the pump H-3. Coming out of the pump H-3 stream 28 is divided into two parts, one of which pipeline 29, return to the reactor R-1, another - excess providerone hydrocarbon fractions With3-C5as a recycle stream 30 is directed to mixing with fresh feedstock pyrolysis and further into the furnace P-1. The gas flow 31 of the separator E-4 is sent to the fuel.

Atlanterra fraction pipeline 24 is introduced into the chlorination reactor R-2. There also serves chloro - stream 32. The reaction is carried out in an environment dichloroethane (EDC) in the presence of Fel 3as the catalyst. The exhaust from the reactor R-2 gas-vapor stream 33 for condensing EDC served in the cooling heat exchanger T-9. The cooled stream from the heat exchanger T-9 is sent to the tank E-5. Part of EDC in the form of a stream 34 return to the reactor R-2 to maintain a constant level of the liquid phase. Another part, the thread 35 is injected into the column K-4. The gas phase from the tank E-5 pipeline 36 serves in adsorber a-1 cleaning from hydrogen chloride, chlorine and chlorinated compounds. Purified in activated charcoal canister gas 37 is directed into the furnace of pyrolysis of P-1 as fuel.

From the top of column K-4 output light components 38. CBM product column K-4 through the pipe 39 is introduced into the column K-5, astride which the selected commodity EDC thread 40. From the cube column K-5 eliminate heavy chlorohydrocarbons thread 41 for recycling.

Examples 1-4

The process is carried out in accordance with the present invention, according to the technology illustrated in the above diagram. Raw material for production of EDC - Atlanterra fraction comprising hydrocarbons, C1-C2with a mixture of hydrogen and carbon oxides with ethylene concentration from 54 to 65 wt.% separated from the gaseous products of pyrolysis - pyrogas obtained by the pyrolysis of propane-butane fraction in a tube furnace. Additionally from the pyrogas allocate a fraction of hydrocarbons With3-C5.

In the course atlantageorgia fraction 68,5%, fractions With3-C5by 26.8%.

The composition atlantageorgia fraction, wt.%:

H2-3.18;

CO-0,04;

CO2-0,09;

H2S-0,01;

CH4-34,74;

With2H2-1,19;

With2H4-54,7;

With2H6-6,02;

With3H6-0,02

The composition of the fraction3-C5, wt.%:

With3H4-2,3;

With3H6-47,8;

With3H8-28,2;

With4H6-9,0;

C4H8to-4.5;

With4H10-5,2;

C5 unsaturated-2,5

C5H12-0,5.

Atlanterra fraction of the above composition is subjected to chlorination in a solution of dichloroethane at a pressure of 0.6 MPa and a temperature of ˜105°in the presence of FeCl3.

Released heat of reaction partially divert flue gas containing oxides of carbon, methane, hydrogen and inert, partly with the cooling water through the built-in reactor heat exchangers.

The conversion of ethylene is 99,3%, chlorine - 99,7%.

The second fraction separated from the pyrolysis products, hydrocarbons3-C5hydronaut in the presence of a palladium catalyst at a pressure of 2.9 MPa, a temperature of 70-90°and the ratio of N2/FR. With3-C5=200 nm3/m3.

Conversion of dienes is 100%olefin - 94%. The mass ratio of fresh and recycle raw materials supplied to the pyrolysis, support is up 0.05 to 1.00:1. Conditions and results of the proposed method dichlorethane production of gaseous products of pyrolysis of hydrocarbons are presented in the table.

Examples 5-7 (comparative)

The process is carried out analogously to example 1-4, except that in example 5, the ratio of recycling:fresh raw materials stated above, the concentration of ethylene in atlantageorgia fraction that is used as a raw material for EDC: example 6 below stated, as in the example 7 above stated. Conditions and results of the proposed method dichlorethane production of gaseous products of pyrolysis of hydrocarbons are presented in the table.

Examples 8-10

The process is carried out analogously to examples 1-4, except that the sin from which emit Atlanterra fraction, obtained by pyrolysis gasoline. The conditions and process indicators in the table.

Example 11 (comparative)

The process is carried out analogously to example 6, except that the sin, which produce raw materials for the EDC, is obtained from fresh raw materials without recycling of hydrocarbons3-C5. The conditions and process indicators in the table.

Example 12

The method is carried out as example 1, except that the sin from which emit Atlanterra faction - raw materials for the teaching EDC, produced by pyrolysis of ethane. The conditions and process indicators in the table.

Example 13

The method is carried out analogously to example 1, except that the sin from which emit Atlanterra faction - raw material for production of EDC, produced by pyrolysis of vacuum gasoil. The conditions and process indicators in the table.

Example 14 (comparative)

The process of obtaining dichloroethane carry out catalytic liquid-phase chlorination of ethylene with a concentration of ˜ 100% [1]. Chlorination of lead in the environment EDC in the presence of FeCl3as the catalyst. The conditions and process indicators in the table.

Example 15 (comparative)

The process is carried out in accordance with the method of the prototype [3]. For chlorination use Atlanterra fraction isolated from the pyrogas obtained by pyrolysis gasoline. Concentration atlantageorgia faction ˜ 39%. The conditions and process indicators presented in the table. High calorific value fuel gas in this example, column 11, is caused other than in the examples according to the invention, the composition of the fuel gas discharged from the gas chlorination.

As can be seen from the table, the use of recycling providerone fraction3-C5in the amount specified in relation to fresh raw materials - examples 1-4, 8-10, 12-13 pyrolysis is ubago hydrocarbons from a gaseous to a heavy liquid, allows you to receive additional ethylene, and hence the product of its chlorination - dichloroethane, an average of 27-28% compared with the method of the prototype column 8. No recycling gidrirovannoe fraction3-C5in raw pyrolysis significantly increases the consumption of fresh raw materials. At higher recycling ratio:fresh raw materials, significantly increases the consumption of cold - example 5.

In addition to the increased yield of EDC in the proposed method, the saving of energy costs on average 2, 3 times a tonne of ethylene compared with the method of the prototype [3] - column 5, examples 1-4, 8-10, 12-13. The performance of the chlorination reactor - column 10, in accordance with the present invention, increases in ˜ 2.2 times compared with the performance of the chlorination reactor in the method-prototype (example 15). When this is achieved, the maximum production of the fuel fraction.

An increased amount of the fuel fraction is necessary for heavy pyrolysis gasoline and heavier oil fractions (atmospheric and vacuum gas oil), as this is not enough fuel discharged from the flue gas chlorination, and it has partly to add from the side.

The decrease in the concentration of ethylene up to 50% leads to increased consumption of raw materials, a noticeable decrease in the performance of chlorination reactor example 6), as well as increased fuel fraction. Increasing the concentration of ethylene in atlantageorgia fraction supplied to the chlorination, over 65% (example 7) leads to a sharp increase in the consumption of cold on the stage atlantageorgia fraction of the products of pyrolysis of hydrocarbons, while the isotherm negative temperature decreases with the average -50°With up to -98°C. This requires a substantial increase in energy costs in the production of cold.

Thus, using the present invention allows to increase the output of dichloroethane in the calculation of the fresh raw materials, reduce energy costs for cold production, to reduce the cost of fuel for pyrolysis furnace with a simultaneous increase in the performance of the chlorination reactor.

The method of producing dichloroethane in accordance with the present invention can be used, after appropriate modernization of production, petrochemical industry.

The method of producing dichloroethane from the gaseous products of pyrolysis of hydrocarbons, including the division of the pyrolysis products with the release atlantageorgia faction and its subsequent liquid-phase catalytic chlorination, characterized in that the pyrolysis is carried out in a tubular furnace, Atlanterra fractious gaseous pyrolysis products produce with the concentration of ethylene 54-65 wt.%, additionally allocate a fraction of hydrocarbons With3-C5, which is subjected to exhaustive hydrogenation, the hydrogenation product is mixed with fresh feedstock mass ratio of 0.05 to 1:1 and sent for pyrolysis, and gas phase products from the chlorination purified and sent to the pyrolysis furnace as fuel.



 

Same patents:

FIELD: chemistry, in particular utilization of chlorine-containing waste.

SUBSTANCE: claimed method includes passing of organochlorine compound vapors blended with oxygen-containing reaction gaseous mixture through catalyst layer providing oxidation of starting organochlorine compounds. Said catalyst represents geometrically structured system from microfibers with length of 5-20 mum. Catalyst has active centers which are characterized by presence of absorption band in absorbed ammonia IR-spectrum with wave number ν = 1410-1440 cm-1; contains platinum group metal as active ingredient; and glass fiber carrier. Said carrier in NMR29Si-spectrum has lines with chemical shifts of -100±3 ppm (Q3-line) and -110±3 ppm (Q4-line) in integral intensity ratio of Q3/Q4 = 0.7-1.2; in IR-spectrum it has hydroxyl absorption band with wave number ν = 3620-1440 cm-1 and half-width of 65-75 cm-1; has specific surface, measured by BET using argon thermal absorption: SAr = 0.5-30 m2/g; surface area, measured by alkali titration: SNa = 10-250 m2/g, wherein SNa/SAr = 5-30.

EFFECT: selective oxidation of starting organochlorine compounds to safe and easily utilizing substances without toxic by-product formation.

3 cl, 4 ex

The invention relates to petrochemistry, and more specifically to the separation of 1,2-dichloroethane

The invention relates to the management of chemical-technological processes carried out in a cascade of reactors for producing 1,2-dichloroethane by chlorination of ethylene in recogida reaction mass
The invention relates to the chemical industry and plastics

The invention relates to the production of 1,2-dichloroethane by direct chlorination of ethylene in the liquid dichloroethane

The invention relates to a method for producing 1,2-dichloroethane by reacting Athena with hydrogen chloride and oxygen or oxygen-containing gas on copper-containing catalyst in the fluidized bed

The invention relates to the production of dichloroethane by direct chlorination of ethylene in the liquid dichloroethane

The invention relates to the production of 1,2-dichloroethane (ethylene dichloride , ejh) by introducing ethylene and chlorine in the circulating ejh under vigorous stirring and heat recovery

FIELD: industrial organic synthesis.

SUBSTANCE: invention is dealing with production of chlorohydrocarbons exhibiting plasticizing properties in polymer compositions in production of synthetic building materials, varnishes and paints, artificial films and leathers, in rubber industry, and as fire-retardant additives in polymers. Process comprises chlorination of waste obtained in production of C14-C32 fraction by ethylene-α-olefin oligomerization. Chlorination is accomplished in two steps: addition chlorination at 35-55°C followed by substitution chlorination at 40-105°C. Chlorohydrocarbons thus obtained can, in particular, be used as secondary plasticizer in polyvinylchloride compositions.

EFFECT: reduced expenses due to using production waste.

4 tbl, 30 ex

The invention relates to the technology of organic synthesis, in particular, to a method for producing chlorinated hydrocarbons having plasticizing properties of polymer compositions in the industry of synthetic building materials, paints and varnishes, synthetic films and leathers, rubber industry, as well as ontamarama additives to various polymers

The invention relates to the technology of organic synthesis, in particular to a method for producing chlorinated hydrocarbons used as plasticizers for polymeric compositions in the industry of synthetic building materials, paints and varnishes, synthetic films and leathers, rubber industry, as well as ontamarama additives to various polymers

The invention relates to the management of chemical-technological processes carried out in a cascade of reactors for producing 1,2-dichloroethane by chlorination of ethylene in recogida reaction mass

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The invention relates to organic chemistry, in particular to a method of obtaining Pentafluoroethane, which is used in the reactions telomerization and as raw material for the preparation of many organic compounds

FIELD: industrial organic synthesis.

SUBSTANCE: invention is dealing with production of chlorohydrocarbons exhibiting plasticizing properties in polymer compositions in production of synthetic building materials, varnishes and paints, artificial films and leathers, in rubber industry, and as fire-retardant additives in polymers. Process comprises chlorination of waste obtained in production of C14-C32 fraction by ethylene-α-olefin oligomerization. Chlorination is accomplished in two steps: addition chlorination at 35-55°C followed by substitution chlorination at 40-105°C. Chlorohydrocarbons thus obtained can, in particular, be used as secondary plasticizer in polyvinylchloride compositions.

EFFECT: reduced expenses due to using production waste.

4 tbl, 30 ex

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