The method of obtaining fluorinated monomers

 

(57) Abstract:

Pure fluorinated monomers with a high output is produced by pyrolysis of fluoropolymers when applying powdered polymer with steam in a fluidized bed reactor. As a material of the fluidized bed of inert granular material, and water vapor is used as a fluidized bed gas. The pyrolysis temperature of 500-900oC. Preferably carry out the pyrolysis of tetrafluoroethylene polymer. Developed new technology for the decomposition of polymers. 2 C.p. f-crystals, 2 tab. 1 Il.

Obtaining fluorinated monomers by pyrolysis of fluoropolymers are known. For example, the application of the U.S. 3832411 describes a method of producing tetrafluoroethylene by pyrolysis of polytetrafluoroethylene, when the pyrolysis is carried out by heating with steam at a temperature of between about 405 and 760oC and without application of vacuum, with the molar ratio of water vapor to the products obtained in the pyrolysis of at least 1:1.

In this method, the polytetrafluoroethylene is applied on a porous surface, such as a sieve of wire mesh and covered by the screen material on top of or lined with all CX vapor and gaseous products of decomposition.

Molten polytetrafluoroethylene flows through the porous substrate and forms at this stalactites, and available hot steam can decompose the polymer before the melt drops can reach the bottom of the tank.

Therefore, the implementation of this method and management is very expensive and practically possible only periodically.

Now found that this method lends itself well to the regulation, if the polymer to be subjected to pyrolysis, continuously served in a heated fluidized bed reactor, which contains the material fluidized bed of inert granular material.

As the fluidized gas is water vapor. From thesis Jurgen Merkel, University of Hamburg, Department of chemistry, 1982, known pyrolysis of polytetrafluoroethylene in the fluidized bed.

In this method, the polymer is served in a fluidized bed containing sand, at a temperature of from 720 to 790oC, especially at a temperature of 760 and 790oC. In contrast to the method according to the invention a part of the gaseous fission products as a medium fluidized bed is allocated back to the reactor in a cyclic process.

At lower temperatures of about 650oC/ formed about 38 weight. % waxy products that cause buildup on the walls, sticking to walls and obstructions.

Further, there are approximately 2 wt.% liquid products. Therefore, this method does not acquire special significance.

In contrast to this known method, the method of application of the fluidized bed according to the invention receive the required monomers with high yield and with virtually no harmful high molecular weight products resulting from pyrolysis. Preferred forms of the invention are explained hereinafter in more detail.

As starting materials suitable fluorinated homopolymers and copolymers in the form of pure polymers, mixtures of different polymers and mixtures of polymers with fillers such as carbon, glass or metals.

Also suitable pastes and dispersions of such polymeric substances. The preferred homopolymer of tetrafluoroethylene, as well as in connection with fillers such as carbon in the form of graphite or carbon, glass or metals like bronze.

In General fit all fillers to the

Fluidized bed is maintained through the supply of steam as a fluid environment. The use of inert gases as a medium fluidized bed in General is not favorable, because they complicate the separation educated monomers.

As the fluidized bed material used mineral substances such as sand, glass, ceramics, oxides of metals such as aluminum, and similar inert substances.

The temperature of pyrolysis is generally in the range between 500 and 900oC. the Heat required for pyrolysis, can be submitted either by means of hot steam, and by additional direct or indirect heating, for example, the walls of the reactor.

The preferred pyrolysis temperature of between 600 and 750oC, in particular in the range between 625 and 675oC. After pyrolysis of the mixture of water vapor with the products resulting from pyrolysis, released in the cyclone from entrained particles of solid matter and by introducing water rapidly cools, water vapor condenses.

Directly behind the products resulting from pyrolysis, dried, for example, using concentrated Vania suitable fluorinated monomers with high yield. In the case of polytetrafluoroethylene get tetrafluoroethylene, hexaferrites and perftorsilanami with almost quantitative yield. Liquid or solid by-products resulting from pyrolysis, are formed only in very small quantities.

In the following examples, the invention is explained in more detail.

Examples. Equipment used in the following examples, shown in the drawing in the form of a schema. It /1/ - capacity storage /2/ auger dispenser /3/ - cooled immersed tube /4/ - fluidized bed, /5/ - electric heating, a /6/ - temperature sensor/thermocouple/, /7/ - cyclone /8/ fridge /fridge for quick cooling/, /9/ - extractor /10/ - capacity device for sampling and /11/ gas meters /rotameters/.

/12/ the - inlet pipe of the steam generator, while the vapor through the inlet pipe /13/ and /14/ sent in a fluidized bed. Gases released during pyrolysis, fall through the supply pipe /15/ cyclone and from there through the inlet pipe /16/ in the fridge, which through the supply pipe /17/ is filled with water.

Then out of the fridge /8/ gases released during pyrolysis, fall through the supply pipe /8/ extractor /the camping during pyrolysis, enter through the inlet pipe /20/ in a container with a device for sampling /10/.

Testing: capacity for storage /1/ containing powdered PTFE /PTFE/ with an average particle diameter of about 0.5 mm. He continuously goes through screw feeder /2/ through chilled immersed tube /3/ with water vapor from the inlet pipe /13/ in a heated fluidized bed containing sand /4/.

This fluidized bed consists of 140 g of sea sand with a particle size of from 0.3 to 0.4 mm, the pyrolysis Temperature of /temperature fluidized bed containing sand/ below in the examples. Fluidized bed has a cross-sectional sizes from 7 to 5, see Below for more water vapor /40% of total / through the supply pipe /14/ gets blown through the bottom, which limits the fluidized bed /4/ bottom. The temperature of the water vapor is 500oC, the rate of flow through the inlet pipe /12/ 5g/min Allocation of the total quantity of water vapor 60% vol. through the supply pipe /13/ 40% vol. through the supply pipe /14/ regulated through valves and rotameters /11/. Absolute pressure is 1 bar.

The gaseous products obtained in ray in the cyclone /7/ from entrained particles of solid matter.

Then gases enter through the inlet pipe /16/ in the fridge for quick cooling /8/ in which gases in the reaction, cooled by injecting water through the supply pipe /17/ when this water vapor condenses.

Then the gases released during pyrolysis, are moving through the pipe /18/ extractor /9/, through which the inlet pipe/19/ is filled with sulfuric acid.

Then the gas mixture, dried with sulfuric acid, enters through the inlet pipe /20/ capacity /10/ unit for sampling.

Changing the test parameters table shows.1, the test results are presented in table.2.

1. The method of obtaining ftorirovannykh monomers by pyrolysis of fluorinated polymers in the presence of water vapor, characterized in that the reaction of interaction carried out in a fluidized bed reactor, which contains as fluidized material inert granular material, and as a fluidized bed gas serves water vapor.

2. The method according to p. 1, characterized in that the use of a polymer of tetrafluoroethylene.

3. The method according to p. 1 or 2 characterized in that the pyrolysis is carried out at a temperature of

 

Same patents:

The invention relates to the production of freon connection, which is used as a refrigerant and as an intermediate in the synthesis of organofluorine compounds and the solvent in polymerization processes

The invention relates to the purification of Pentafluoroethane (HFC-125), used as ozone-safe coolant and propellant in various branches of engineering, from the admixture of pentafluorobutane (halon-115)

-forefire, the method of production thereof" target="_blank">

The invention relates to a method for producing (halo) fluorocarbons used as cooling agents, foaming agents, solvents and propellants
The invention relates to chlorination to obtain 1,1,1-trichlorotrifluoroethane

The invention relates to the synthesis of TETRAFLUOROMETHANE of carbon and fluorine

The invention relates to a method of separation of HF from liquid mixtures containing HCFC 123 and/or 124 (freon 123 and/or 124)

FIELD: chemical industry; a method and an installation for treatment of a solid powder fluoropolymer.

SUBSTANCE: the invention is pertaining to the field of chemical industry, to a method and an installation for treatment of a solid powder fluoropolymer. The method provides for: generation in a zone of high temperature of an electric arc between at least one cathode and at least one anode; generation in the zone of high temperature and using an electric arc and the gaseous plasma, a conflagrant up thermal plasma having a caudal torch; formation of a chemically active thermal mixture of the thermal plasma with the caudal torch, and a fluoropolymer, which dissociates with formation at least of one precursor of fluorocarbon or other chemically active varieties for formation at least of one monomeric fluorocarbon compound. The invention also presents the installation for treatment of a solid powder fluoropolymer and the sonde for the plasma reactor switching off. The invention presents the method and the installation for production of monomeric fluorocarbon compounds from the solid powdery fluoropolymers.

EFFECT: the invention presents the method and the installation for production of monomeric fluorocarbon compounds from the solid powdery fluoropolymers.

29 cl, 2 ex, 2 dwg

FIELD: methods of treatment of fluocarbon raw.

SUBSTANCE: the invention is pertaining to the methods of treatment of fluocarbon raw. The method of treatment of fluocarbon raw provides for heating by means of high frequency induction of a heating zone of a reaction chamber up to the temperature of no more than 950°C, heating in the heating zone of fluocarbon raw, which contains at least one fluocarbon compound, so, that the fluocarbon compound dissociates with production of at least one predecessor of fluocarbon or its reactive kinds; and refrigerating of the predecessor of fluocarbon or its reactive kinds, in the result of which from the predecessor of fluocarbon or its reactive kinds forms at least one more desirable fluocarbon compound. The technical result is conversion of the fluocarbon raw into the useful products by the low-cost reliable non-polluting environment universal and easily controlled method.

EFFECT: the invention ensures conversion of the fluocarbon raw into the useful products by the low-cost reliable non-polluting environment universal and easily controlled method.

12 cl, 10 dwg, 3 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: described is a method of processing polytetrafluoroethylene wastes through continuous pyrolysis in the presence of water vapour at high temperature, distinguished by that pyrolysis is carried out in two successive steps, where pyrolysis temperature at the first step is 600-750°C, and 500-600°C at the second step. Temperature at the first step is higher than temperature at the second step.

EFFECT: owing to decomposition in two steps, the method enables simultaneous production of fluoro-monomers and fine-dispersed polytetrafluoroethylene.

2 cl, 4 ex, 1 tbl, 1 dwg

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing fluoro-organic compounds. Method involves the gas-phase catalytic hydrofluorination of trifluoroethylene at increased temperature in the presence of the chrome-magnesium-fluoride catalyst comprising 8-24 wt.-% of trivalent chrome fluoride uniformly distributed in magnesium fluoride with the dispersity index from 0.125 to 0.315 mm. The process is carried out at temperature 140-190C and time contact for 4.5 s. Method provides the high yield of 1,1,1,2-tetrafluoroethane with selectivity index up to 99.9%.

EFFECT: improved preparing method.

2 tbl, 7 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluoropropane. Method is carried out by interaction of crude octafluoropropane comprising impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that are able to remove indicated impurities up to the content less 0.0001 wt.-% from indicated crude octafluoropropane. The impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurities represent at least one compound taken among the group consisting of chloropentafluoroethane, hexafluoropropene, chlorotrifluoromethane, dichlorodifluoromethane and chlorodifluoromethane. Adsorbent represents at least one substance taken among the group consisting of activated coal, molecular sieves and carbon molecular sieves. Crude octafluoropropane comprises indicated impurities in the amount from 10 to 10 000 mole fr. by mass. Invention proposes gas, etching gas and purifying gas comprising octafluoropropane with purity degree 99.9999 wt.-% and above and containing chlorine compound in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluoropropane.

EFFECT: improved purifying method.

13 cl, 11 tbl, 12 ex

FIELD: chemical technology.

SUBSTANCE: invention relates to processing liquid fluorocarbon raw to valuable fluorine-containing gaseous products and to quenching probe method used (abrupt cooling). Method for treatment of fluorocarbon raw involves generation of high temperature in the zone of arc between at least one cathode and at least one anode, generation of high temperature in the zone by electric arc and gaseous thermal plasma with tail torch. Chemical active thermal mixture with tail torch of thermal plasma is formed from fluorocarbon raw that comprises at least one fluorocarbon compound. Fluorocarbon compound dissociates and forms at least one fluorocarbon precursor or its chemically active species having less carbon atoms as compared with fluorocarbon compound. Then chemically active thermal mixture is cooled to form fluorocarbon from the precursor or chemically active species of fluorocarbon product. Preferably, raw has a liquid form and represents fluorocarbon by-side products comprising two or more fluorocarbon compounds being one of them represents the main product containing less five carbon atom usually. Preferably, raw is added to the tail torch of plasma and plasma is fed to the high temperature zone. The self-cleansing quenching probe comprises external cylindrical component assembled on reactor and having the central channel for cooling hot gas or chemically active thermal mixture. The internal cylindrical component is installed with a gap inside of the external component and used for cooling hot gas or chemically active thermal mixture that pass through peripheral gap between components. Method provides reducing exploitation consumptions, possibility for regulating parameters of the process and the composition of feeding mixture and the yield of end products.

EFFECT: improved method for processing.

20 cl, 5 tbl, 3 dwg, 7 ex

FIELD: organic chemistry.

SUBSTANCE: claimed method includes interaction of mixture C3-C6-hydrofluoroalkane/hydrogen fluoride in absence of catalyst with at least one chloro-containing or cloro- and fluoro-containing organic compound reactive towards hydrogen fluoride in liquid phase. Hydrofluoroalkane is obtained by interaction of at least one chloro-containing or cloro- and fluoro-containing precursor with hydrogen fluoride in the first step. In one of the next steps at least part of products from the first step is made to react with hydrogen fluoride, wherein one step includes separation method. Also disclosed are azeotrope or pseudo-azeotrope composition applicable for 1,1,1,3,3-pentafluorobutane purification. Claimed composition contains as main components 1.5-27.5 mol.% of 1,1,1,3,3-pentafluorobutane and 72.5-98.5 mol.% of hydrogen fluoride.

EFFECT: method with optimized parameters.

16 cl, 4 dwg, 1 tbl, 5 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a new mixture of perfluoro-, α-chloroperfluoro- and α,ω-dichloroperfluoroalkanes of the formula: X(CF2)nY (wherein X = Y means F, Cl; X means F; Y means Cl; n = 12, 14, 16) used as powder-accelerators for plastic ski, and to a method for preparing these mixtures. Method for preparing mixtures of perfluoro-, α-chloroperfluoro- and α,ω-dichloroperfluoroalkanes involves interaction of perfluoro- and ω-chloroperfluorocarboxylic acids with potassium alkali at temperature below 60°C and then with potassium persulfate at 90-95°C. As the parent acid method involves using mixtures of perfluoroenanthic acid and ω-chloroperfluoroenanthic acid, perfluoroenanthic acid and ω-chloroperfluoropelargonic acid, perfluoropelargonic acid and ω-chloroperfluoroenanthic, perfluoropelargonic, ω-chloroperfluoropelargonic, ω-chloroperfluoroenanthic and ω-chloroperfluoropelargonic acids taken in the mole ratio = 1:1. Process is carried out in the mole ratio of acids mixture and potassium persulfate = 1:0.6. The developed method provides preparing new mixtures of powder-accelerators for plastic ski based on domestic raw.

EFFECT: improved preparing method, valuable properties of mixtures.

4 cl, 4 tbl, 9 ex

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for isolation of 1-fluoro-1,1-dichloroethane, 1,1-difluoro-1-chloroethane, 1,1,1-trifluoroethane and hydrogen chloride from reaction mixture prepared by synthesis of vinylidene chloride and hydrogen fluoride. Process involves separating for layers and rectified separation. Gaseous mixture synthesis consisting of 1-fluoro-1,1-dichloroethane, 1,1-difluoro-1-chloroethane, 1,1,1-trifluoroethane, hydrogen fluoride and hydrogen chloride is absorbed with liquid mixture of substances prepared after separating for layers. The liquid mixture of substances comprises hydrogen fluoride, 1-fluoro-1,1-dichloroethane and 1,1-difluoro-1-chloroethane. Gaseous substances are fed for rectified separation and distillate obtained after rectifying that comprises hydrogen chloride and 1,1,1-trifluoroethane is fed for rectified separation and 1,1,1-trifluoroethane is recovered inversely for rectification in the amount determined by temperature and pressure values of the distillate condensation process. Vat product containing hydrogen fluoride, 1-fluoro-1,1-dichloroethane and 1,1-difluoro-1-chloroethane is fed for separating for layers and then prepared hydrogen fluoride with impurities of organofluoric compounds is recovered for absorption as liquid spraying. Mixture enriched with 1-fluoro-1,1-dichloroethane, 1,1-difluoro-1-chloroethane and containing hydrogen fluoride is fed for rectification wherein hydrogen fluoride as a component of mixture with 1,1-difluoro-1-chloroethane that is similar by the content of components to azeotropic mixture is separated and recovered its for repeated separating for layers and rectification. After repeated separation hydrogen fluoride is recovered for the synthesis. Mixture of 1-fluoro-1,1-dichloroethane and 1,1-difluoro-1-chloroethane is fed for rectified separation. Method provides increasing yield of commercial products as result of evolving gases synthesis of vinylidene chloride and hydrogen fluoride, simplifying the process and prevents accumulation of by-side products in the process.

EFFECT: improved method for isolation.

2 cl, 1 dwg, 4 ex

FIELD: chemical industry; methods and devices for reprocessing of the trifluotomethanesulfofluoride into the salt of the triluoromethanesulfo acid.

SUBSTANCE: the invention is pertaining to the improved method of production of the, which is the source product for the synthesis the trifluoromethanesulfofluoride derivatives of the triluoromethanesulfo acid, which are used in the thin organic synthesis, in production of the drugs, fungicides, extractants, catalysts, and also to the device for the method realization. The technical result of the invention is intensification of the process, the increase of productivity, the decrease of the losses of the trifluoromethanesulfofluoride at its reprocessing into the salt of the triluoromethanesulfo acid. The solution of the problem provides for feeding of the trifluoromethanesulfofluoride in its gaseous state into the mixture of the hydroxide (or oxide) the alkali-earth or the alkali metal with the water at the constant control of the pH value of the water mixture and the stopping delivery of the trifluoromethanesulfofluoride at рН=7. At that the trifluoromethanesulfofluoride is fed in the descending loop of the circulation of the water mixture at the volumetric ratio of the water mixture to the gas of not less than 6 and under the constant control of the contents of the trifluoromethanesulfofluoride in the effluent gases; feeding of the trifluoromethanesulfofluoride is terminated if its concentration in the effluent gases exceeds 0.5 % of their volume.

EFFECT: the invention ensures intensification of the process of reprocessing of the trifluoromethanesulfofluoride into the salt of the triluoromethanesulfo acid, the increased productivity, the decreased losses of the trifluoromethanesulfofluoride at its reprocessing into the salt of the triluoromethanesulfo acid.

3 cl, 4 ex, 1 dwg

FIELD: chemistry of organophosphorus compounds, chemical technology.

SUBSTANCE: invention describes a method for synthesis of monohydroperfluoroalkanes, bis-(perfluoroalkyl)phosphinates and perfluoroalkylphosphonates. Method involves treatment of at least one perfluoroalkylphosphorane with at least one base wherein base(s) are chosen from group consisting of alkali-earth metal hydroxides, metalloorganic compound in useful solvent or at least one organic base and an acid in useful reaction medium. Also, invention describes novel perfluoroalkylphosphonates and bis-(perfluoroalkyl)phosphinates, using novel perfluoroalkylphosphonates and bis-(perfluoroalyl)phosphinates as ionic liquids, catalysts of phase transfer or surfactants.

EFFECT: improved method of synthesis.

18 cl, 19 ex

Up!