Method for integrated processing of products of oxidative pyrolysis gas metadatareader

 

The invention relates to the processing of the products of oxidative pyrolysis metadatareader gas. The method is carried out by catalytic hydrochlorination of acetylene contained in the pyrolysis gases. Abgas containing hydrogen and oxides of carbon, away from the upper part of the absorber and is directed to the synthesis of ammonia or methanol. Methanol is used in the absorption process in the selection of vinyl chloride. CBM product absorber, representing saturated with chloride methanol, sent for desorption, which is carried out in two stages. The gas flow of desorber first stage return in the lower part of the absorber. The ratio of the volume of gas flow from desorber first stage and absorbate directed to the power of desorber is (0,351,85):1. VAT product desorber first stage is directed to the upper part of desorber second stage, where the final desorption of vinyl chloride, which is sent for rectification, and receive trade vinyl chloride. The technical result - obtaining vinyl chloride polymerization of purity. 1 Il., table 2.

The invention relates to the refining and petrochemical industry

Contained in the products of oxidative pyrolysis metadatareader acetylene gas, oxides of carbon and hydrogen can serve as a raw material for a number of large facilities, such as vinyl chloride, ammonia and methanol.

A method of refining acetylene obtained by cracking of natural gas. Acetylene using catalytic hydrochlorination turn to vinyl chloride (Sci. Res. , 4 (2-3), (Dacca, Pakistan)) [l]. Other cracking products in this way are not used.

Of the products of thermal cracking gasoline (Japan Patent 19.808 (67), 1966) [2] use acetylene and ethylene, first as a raw material for vinyl chloride, the second for the alkylation of benzene to ethylbenzene. Last digitalout in styrene. Obtained in this process, the vinyl chloride absorb from the gaseous reaction mixture with benzene and purified by distillation. After distillation purification of benzene is mixed with ethylene in the presence of the alkylation catalyst, the purified benzene is subjected to dehydrogenation chlorine obtaining styrene.

For efficient absorption of vinyl chloride absorbent must be cooled to 0oC and below. In the method [2] the absorbent benzene has a relatively high temperature crystallizes the apparatuses and pipelines will be hammered crystals of benzene. Therefore, to ensure full absorption of vinyl chloride will require 2-3 times more consumption of benzene than other absorbents.

There is a method of processing products of cracking of natural gas, including the hydrochlorination of acetylene, ethylene chlorination and other hydrocarbons contained in these products, obtaining vinyl chloride and saturated aliphatic chlorides (U.S. Patent 2858347, CL 570-219, 1954) [3]. Obtained in this method, the vinyl chloride and saturated aliphatic chlorides absorb trichloroethylene and share fractional desorption at low temperatures to prevent polymerization of vinyl chloride.

Trichloroethylene, used in [3] as the absorbent vinyl chloride, easily polymerized. To ensure complete desorption of vinyl chloride from trichloethylene in a cube of desorber supported relatively high temperature, which leads to polymerization of the absorbent, the driving of the heater and desorber.

A method of refining acethylesterase gas obtained by oxidative pyrolysis of methane (Chem. Prom. 43 (8), S. 566-567) [4]. In addition to acetylene in sin are hydrogen, oxides of carbon and minor amounts of ethylene. In accordance with this venture catalyst, representing activated carbon, impregnated with 10% of mercuric chloride. The process is carried out at a temperature of 110-125oC and a pressure of 5-8 ATM with the use of excessive amounts of hydrogen chloride. Exhaust gases absorb the chlorobenzene, absorbed washed with water to absorb hydrogen chloride and directed to desorber. In desorber the vinyl chloride is separated from chlorobenzene and sent to distillation column for final purification, to produce salable product. The remaining products of oxidative pyrolysis of methane is not used.

Chlorobenzene - absorbent vinyl chloride in the method [4] has a boiling point at atmospheric pressure 132oC. To ensure complete condensation deformiruemogo from chlorobenzene vinyl chloride requires zakolacivatj on the top of the column to a temperature of ~ 40oS, which corresponds to a pressure of ~ 5 ATM and the boiling point of chlorobenzene ~ 200oC. This temperature in a cube of desorber leads to a dramatic acceleration of polymerization of vinyl chloride. To reduce the rate of polymerization of the vinyl chloride desorption is carried out at a pressure close to atmospheric. The temperature at the top of desorber is -13oC. It is ensured by the application of ammonium hall the process.

In the exhaust of desorber gases contain significant amounts of hydrogen chloride and, therefore, all the devices and pipelines after desorber should be made of corrosion-resistant materials, which leads to higher commodity product.

In addition, in the method [4] are not used in the remaining products of pyrolysis, hydrogen and oxides of carbon emitted into the atmosphere. This not only further reduces economic indicators of the production of vinyl chloride from the gaseous products of oxidative pyrolysis of methane, but also affects its ecology.

The present invention, therefore, was the creation of more complex technological, and economical method of processing products of oxidative pyrolysis metadatareader gas while simultaneously improving the environment of the process.

The objective is formulated, in accordance with the present invention is solved by a method for processing products of oxidative pyrolysis metadatareader gas by catalytic hydrochlorination contained acetylene, with subsequent absorption-desorption separation and distillation purification of the obtained vinyl chloride, vinyl chloride absorbing the synthesis of ammonia or methanol, the latter is used in the absorption process in the selection of vinyl chloride, CBM product absorber - absorbed representing saturated with chloride methanol, sent for desorption, which is carried out in two stages, and the gas flow of desorber first stage return in the lower part of the absorber when the ratio of the volume of the gas stream that is returned from desorber first stage in the lower part of the absorber, and absorbate directed from the bottom of the absorber to the power of desorber first stage is (0,351,85): 1, CBM product of desorber first stage is directed to the upper part of desorber second stage, which produces the final desorption of vinyl chloride, from the top of desorber the second stage of the vinyl chloride is sent to a distillation column, in which as the head product is obtained trademark vinyl chloride polymerization purity.

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

The installation includes the hydrochlorination reactor 1, the scrubber 2, the absorber 3, desorbers 4 and 5, the rectifying column 6, reflux condensers 7 and 8, the separators 9 and a basic process flows: 16 - the sin is a mixture of the products of oxidative pyrolysis; 17 - hydrogen chloride, 18 to the reaction mixture, 19 - aqueous solution of caustic soda, 20 aqueous solution of sodium chloride, 21 - neutralized reaction mixture comprising vinyl chloride, oxides of carbon and hydrogen, 22 - a mixture of carbon oxides and hydrogen, is directed to the synthesis of ammonia - 23 or methanol 24, 25 - methanol, 26 - absorbed - methanol saturated with chloride, 27 - vinyl chloride with a mixture of methanol, 28 - methanol with partially desorbed by vinyl chloride, 29 - methanol mixed with water, recyclery in the absorber 3 to the absorption of the reaction mixture of vinyl chloride, 30 - vinyl chloride with technological impurities (water, methanol), 31 - distillate residual methanol with water, 32 - trademark chloride.

In accordance with the present invention in the hydrochlorination reactor 1, which represents a tubular apparatus, tubes filled with catalyst mercuric chloride on charcoal, contact the sin - products of oxidative pyrolysis of natural gas or methane gas stream 16 containing acetylene, a small amount of ethylene, carbon monoxide and hydrogen, with the hydrogen chloride stream 17. Coming out of the reactor 1, the gas flow of the reaction mixture 18 is directed at the bottom todat aqueous solution of sodium chloride. From the top of scrubber 2 neutralized reaction mixture 27 is directed into the lower part of the absorber 3. From the top of the absorber abgas 22 containing hydrogen and oxides of carbon, send to the site for the synthesis of ammonia 23 or at the site of methanol synthesis 24. From the site of synthesis of a stream of methanol 25 is directed into the upper part of the absorber 3, which is saturated with vinyl chloride. Absorbed 26 by pump 15 is served in the upper part of desorber first stage 4, where there is a partial evaporation of vinyl chloride from absorbate. Released by the vinyl chloride from the top of desorber first steps 4 through the reflux condenser 7 and the separator 9 in the form of a gas stream 27 return to the bottom of the absorber 3 when the ratio of the volume of the gas stream 27 and absorbate 26 supplied to the power of desorber first stage 4, is equal to (0,351,85):1. CBM product from the lower portion of desorber first-stage 4 - thread 28 through the heat exchanger 12 is directed into the upper part of desorber second stage 5. Application of heat in the desorbers 4 and 5 are carried out through immersion heaters 11 and 13, respectively. From the top of desorber second stage 5 desorbed vinyl chloride - flow 30 through the reflux condenser 8 and the separator 10 is directed to a distillation column 6. From the bottom of decor illore polymerization purity obtained as the head product of the distillation column 32 6. From the cube column 6 output resinous substances and water - flow 31. At initial start-up setup processing of the products of oxidative pyrolysis of natural gas or methane for absorption of synthetic vinyl chloride use imported methanol.

Examples 1-5.

In accordance with the above description of the process perform complex processing of the products of oxidative pyrolysis of obtaining vinyl chloride and ammonia or methanol. Technological and process indicators hydrochlorination of acetylene contained in the sin table. 1, the isolation and purification of vinyl chloride - table. 2.

Example 6 (comparative).

The hydrochlorination products of oxidative pyrolysis of methane is carried out in accordance with the method of the prototype [4]. Technological and process indicators hydrochlorination of acetylene contained in the sin table. 1., - isolation and purification of vinyl chloride - table. 2.

As can be seen from the data table. 1, when hydrochloridebuy products of oxidative pyrolysis metadatareader gas, in accordance with the present invention, achieved by reducing the material intensity of instrumentation and loss of hydrogen chloride. the Alov, and significantly improves the ecology of the process through the use of close to the stoichiometric ratio of acetylene: hydrogen chloride and the practical absence in abgase hydrogen chloride.

The data table. 2 suggests that, during the hydrochlorination, in accordance with the present invention, the flow rate of the absorbent is reduced by more than 30% compared to [4], the closest to the present invention similar. Using a two-step desorption can significantly reduce the entrainment of vinyl chloride with the exhaust gases. The temperature drop in the desorbers both stages, thanks to the use of methanol as absorbent leads to a significant reduction in heat consumption at the stage of selection of vinyl chloride and 20-fold decrease in the rate of polymerization of vinyl chloride. All this, ultimately, allows to increase the output of commodity vinyl chloride ~ 10% in comparison with the method of the prototype. An additional advantage of the invention is the reduction in 2, 3 times flow rate of cold in the absorber.

In addition, to more fully use the products of oxidative pyrolysis, from which useful are involved in the processing not only of acetylene, but also their processing allows not only useful and a better use of the products of oxidative pyrolysis metadatareader gas, but do it with a higher economic and technological performance, while improving the environmental process.

We offer a comprehensive way of processing the products of oxidative pyrolysis metadatareader gas can be used, after appropriate modernization of production at enterprises of the petrochemical industry.

Claims

A method of processing products of oxidative pyrolysis metadatareader gas by catalytic hydrochlorination contained acetylene, with subsequent absorption-desorption separation and distillation purification of the obtained vinyl chloride, characterized in that the vinyl chloride absorb methanol abgas containing hydrogen and oxides of carbon withdrawn from the upper part of the absorber, is directed to the synthesis of ammonia or methanol, the latter is used in the absorption process in the selection of vinyl chloride, CBM product absorber-absorbed representing saturated with chloride methanol, sent for desorption, which is carried out in two stages, moreover, the gas flow of desorber first stage return in the lower part of the absorber when the ratio of the volume of gas from the lower part of the absorber to the power of desorber first stage, equal (0,351,85):1, CBM product of desorber first stage is directed to the upper part of desorber second stage, which produces the final desorption of vinyl chloride, from the top of desorber the second stage of the vinyl chloride is sent to a distillation column, in which as the head product is obtained trademark vinyl chloride polymerization of purity.

 

Same patents:
The invention relates to the chemical industry and plastics

The invention relates to the production of vinyl chloride

The invention relates to a method for producing vinyl chloride by thermal pyrolysis of dichloroethane

The invention relates to a method for producing vinyl chloride by thermal pyrolysis of dichloroethane

The invention relates to a technology for chlorohydrocarbons by the chlorination of olefins, in particular to a device for receiving allylchloride used as intermediate for a number of organic production - allyl alcohol, glycerol, etc

The invention relates to a method of producing allylchloride to the reactor for its implementation

The invention relates to a method of producing allylchloride gas-phase chlorination of propylene under pressure at 430-470C

The invention relates to a method for separation of the products of pyrolysis of dichloroethane in the production of vinyl chloride

The invention relates to a method for producing unsaturated chlorohydrocarbons

The invention relates to the field of organic chemistry, in particular to a method for monochloramine derivatives of adamantane and diamantane, which are used in the production of thermo - and hemostatic polymers that serve as the raw material for the synthesis of medicines and are used in the synthesis of other derivatives adamantanone (amines, alcohols, acids)
The invention relates to an improved process for the preparation of TETRAFLUOROMETHANE used as the low-temperature refrigerant, a reagent for dry etching of semiconductors, fire retardant

The invention relates to a method for producing 1,3-dichloromethane, which is used in the production of thermo - and hemostatic polymers, insecticides and medicines

The invention relates to a method for 1 - and 2-chloroadamantane used to obtain heat-resistant polymers, insecticides, fungicides and pharmaceuticals

The invention relates to a method for Pentafluoroethane by fluorination of halogenorganics connection fluoride of a metal of variable valence

The invention relates to a method for chloroform liquid-phase chlorination of methylene chloride under photochemical initiation, followed by distillation and subjected to chlorination mixture of chlorine-methanes, obtained by thermal chlorination of methane after the removal of her chlormethyl at a molar ratio of methylene chloride to chlorine 4 - 2 : 1 at a temperature of 35 - 45C

The invention relates to a technology for chlorohydrocarbons by the chlorination of olefins, in particular to a device for receiving allylchloride used as intermediate for a number of organic production - allyl alcohol, glycerol, etc

The invention relates to a method of producing allylchloride to the reactor for its implementation

The invention relates to the chlorination of paraffin

The invention relates to the production of chlorine-methanes, primarily chloroform

The invention relates to a method for production of chlorocyclohexane used to obtain cyclohexane, and also as an intermediate in the synthesis of plant protection agents and pharmaceuticals
Up!