Mixture separation containing at least one hydrofluoroalkane and hydrogen fluoride, method for production of hydrofluoroalkane and azeotrope composition

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

 

The present invention relates to a method for separating a mixture containing hydrofluroalkane and hydrogen fluoride, as well as to methods for hydrofluroalkane and azeotropic compositions.

Hydrofluroalkane can be obtained by the interaction of the chlorine-containing precursor with hydrogen fluoride, as described, for example, in patent applications EP-A1-0699649 and WO-A1-97/15540 (in the name of SOLVAY) and in patent application WO-A1-97/05089. In such method, the mixture of reaction products at the outlet of the reactor in addition to the target hydrofluroalkane contains hydrogen chloride, resulting from the removal of one or more chlorine atoms from the source of chlorine-containing precursor, hydrogen fluoride, chlorine - and fluorine-containing intermediates, usually unreacted chlorine-containing precursor, possibly inert diluents, as well as a small number of different products. Because typically use an excess of hydrogen fluoride relative to the chlorinated precursor, often in a mixture of reaction products is a certain amount of unreacted hydrogen fluoride. While the components of the mixture of reaction products can easily be completely separated using distillation, a complete separation of hydrofluroalkane and hydrogen fluoride by distillation is usually difficult to implement, because these is soedineniya often form an azeotropic mixture.

In patent application WO-A1-97/05089 describes a method of cleaning hydro(chloro)Tarakanov (in particular 1,1,1,3,3-pentafluoropropane, or HFC-245fa) from azeotropic mixtures with hydrogen fluoride using the method of azeotropic distillation that includes two successive stages of distillation at different temperatures and pressures.

However, this method of azeotropic distillation has the disadvantage that in order to achieve sufficient potential separation (difference in the composition of the azeotrope at low temperature and pressure and azeotrope at high temperature and pressure) it is necessary to use a large difference in temperature and pressure in the columns and create between two columns considerable circulation stream.

In patent application WO-A1-97/13719 proposes a method of separation and recuperation of hydrogen fluoride from a mixture (azeotrope), containing, along with other substances hydrofluroalkane with 1-6 carbon atoms (in particular HFC-245fa). The mixture is introduced into contact with a solution of fluoride of an alkali metal (in particular potassium fluoride or cesium) and separate the organic phase from the phase containing hydrogen fluoride and a fluoride of an alkali metal.

When using this known method can be fear of contamination of the organic phase with potassium fluoride or cesium and the possibility of decomposition of hydrofluroalkane, which is th can cause such pollution. On the other hand, the alkali metal fluorides, in particular cesium fluoride, are very expensive.

The aim of the present invention is to provide a method of separating a mixture containing at least one hydrofluroalkane having mainly 3 to 6 carbon atoms, and hydrogen fluoride, which would be deprived of the above-mentioned disadvantages.

The invention thus relates to a method for separating a mixture containing at least one hydrofluroalkane and hydrogen fluoride (hereinafter referred to as mixture hydrofluroalkane/hydrogen fluoride, whereby the mixture hydrofluroalkane/hydrogen fluoride is injected into interaction with at least one organic compound that can react with hydrogen fluoride.

The interaction of the mixture hydrofluroalkane/hydrogen fluoride with at least one organic compound that can react with hydrogen fluoride, helps to eliminate at least part of the hydrogen fluoride. The method of separation according to the invention provides thus a mixture of the reaction products with reduced content of hydrogen fluoride. It is of interest in terms of synthesis hydrofluroalkane as mentioned mixture can be, in particular, used as a solvent for extraction. The mixture of reaction products is also very good p is chodit as source material in the case, when it is further subjected to at least one stage of processing to identify hydrofluroalkane. Thus, you may receive hydrofluroalkane, substantially freed from hydrogen fluoride.

Of particular advantage is to be seen in the case when hydrofluroalkane capable of combining with hydrogen fluoride azeotrope, or pseudoesotropia, because it is possible to "split" this azeotrope, i.e., the method of separation according to the invention is able to give a mixture in which hydrofluroalkane and hydrogen fluoride are present in proportions different from those in which they form an azeotrope or pseudoisotopy.

Under hydrofluroalkane mean hydrocarbon compounds corresponding to the General formula CaH(2a+2)-bFbwhere a is from 1 to 6 and b is 1 to 2A+1. Preferred hydrofluroalkane containing 3 to 4 carbon atoms.

As examples of hydrofluroalkane, which can be separated from their mixtures with hydrogen fluoride using the method of separation according to the invention, can be called 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,2,2,3-pentafluoropropane (HFC-245ca), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,3,3,3-hexaferrite (HFC-236fa), 1,1,1,2,3,3-hexaferrite (HFC-236ea), 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea), 1,1,1,3,3-pendaftar-2-methylpropan (HFC-365mps), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), 1,1,1,4,,4-hexaferrite (HFC-356mff), 1,1,1,2,3,4,4,5,5,5-decipherments (HFC-43-10mee). Of these compounds the most preferred 1,1,1,3,3-pentafluoropropane (HFC-245fa), and 1,1,1,3,3-pentafluorobutane (HFC-365mfc). Particularly preferred 1,1,1,3,3-pentafluorobutane (HFC-365mfc).

Organic compounds used in the method of separation according to the invention, capable of reacting with hydrogen fluoride. Examples of organic compounds along with other are normal or branched alkanes, predominantly chlorinated and/or brominated and possibly substituted, containing from 1 to 10 carbon atoms and is possibly substituted alkenes containing from 2 to 10 carbon atoms. Often use chlorine or chlorine - and fluorine-containing organic compounds. Well, for example, suitable halogenated olefins, such as chlorinated, fluorinated or chlorpheniramine olefins, such as vinyl chloride, vinylidenechloride, trichlorethylene, perchlorethylene, vinylidenefluoride, chlorotrifluorethylene or forproperty, such as, for example, hexaferrites.

Mostly organic compound is chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane.

Under chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane means hydrochlorine and hydrochloridecan, i.e. respectively of chlorine and chlorine - and fluorine-containing hydrocarbons is adnie connection containing at least one chlorine atom and at least one hydrogen atom, the same number of carbon atoms as the target hydrofluroalkane, and at least one fluorine atom is smaller than the target hydrofluroalkane. Desired hydrofluroalkane can be obtained from at least one of chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane interaction of the precursor with hydrogen fluoride.

As examples of chlorine-containing and chlorine - and fluorine-containing precursors of hydrofluroalkane suitable for use in the method of separation according to the invention, may be named the following hydrochlorine: 1,1,1, 3,3-pentachloropropane (HCC-240fa), 1,1,2,2,3-pentachloropropane (NCC-AA), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,1,3,3,3-hexachloropropane (HCC-230fa), 1,1,1,2,3,3-HEXAFLUOROPROPANE (HFC-230da), 1,1,1,2,3,3,3-Heptafluoropropane (HCC-220da), 1,1,1,3,3-pentachloro-2-methylpropan (HCC-360jns), 1,1,1,3,3-pentachlorobutane (HCC-360jfa), 1,1,1,4,4,4-hexachlorobuta (HCC-350jff) and 1,1,1,2,3,4,4,5,5,5-dichloropentane (HCC-430jdd), and the following hydrochloridecan: 1-fluoro-1,1,3,3-tetrachlorobutane (HCFC-361kfa), 3-fluoro-1,1,1,3-tetrachlorobutane (HCFC-361jfb), 1,1-debtor-1,3 .3m-trichlorobutane (HCFC-3621fa), 1,3-debtor-1,1,3-trichlorobutane (HCFC-362kfb), 3,3-debtor-1,1,1-trichloroethan (HCFC-362jfc), 1,1-dichloro-1,3 .3m-triptorelin (HCFC-363kfc), 1,3-dichloro-1,1,3-triptorelin (HCFC-3631fb), 3,3-dichloro-1,1,1-triptorelin (HCFC-363mfa), 1-chloro-1,1,3,3-tetrafluroethane (HCFC-364lc) and 3-chloro-1,1,1,3-tetrafluroethane (HCFC-364mfb).

In one embodiment, chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane are (hydro)chloralkali and (hydro)harperley, i.e. respectively of chlorine and chlorine - and fluorine-containing carbon compounds containing at least one chlorine atom and possibly at least one hydrogen atom, the same number of carbon atoms as the target hydrofluroalkane, and at least one fluorine atom is smaller than the target hydrofluroalkane. As examples can be named (hydro)chlorine(fluorine)propane, such as 1-chloro-3,3,3-Cryptocom-1-ene as a predecessor 1,1,1,3,3-pentafluoropropane and (hydro)chlorine(fluorine)butenes, such as DICHLORODIFLUOROMETHANE, such in particular as 1,1-dichloro-1,3-deverbal-2-ene and/or chlorotrifluoroethane such, in particular, as 1-chloro-1,1,3-triflorum-2-ene as precursors 1,1,1,3,3-pentafluorobutane.

The interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound in the method of separation according to the invention is carried out predominantly in the liquid phase.

The interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound in the method of separation according to the invention can be carried out in the presence of a catalyst. It may also be carried out in the absence of a catalyst.

When is vzaimodeistviiu mixture hydrofluroalkane/hydrogen fluoride and the organic compound in the presence of a catalyst, can be used catalysts, promoting the substitution of the chlorine atom by a fluorine atom. Of usable catalysts include compounds of metals selected from metals of groups IIIa, IVa and b and VIb of the Periodic table of elements, and mixtures thereof. More specifically compounds of titanium, tantalum, molybdenum, boron, tin and arsenic. Mostly use compounds of titanium or tin. Particularly suitable compounds of titanium. As metal compounds can be called salts, in particular halides. Mostly use the chlorides, fluorides and chloritoid. Particularly preferred catalysts in the method of obtaining hydrofluroalkane according to the invention are the chlorides, fluorides and chloritoid titanium and tin, and mixtures thereof. Particularly well-suited to the titanium tetrachloride and tin tetrachloride is used.

When the interaction between the mixture hydrofluroalkane/hydrogen fluoride and the organic compound is carried out in the liquid phase, it is done mainly in the absence of a catalyst, which makes it possible to pour the reaction medium in the liquid state and, if necessary, easily be done after one or several stages of distillation.

The molar ratio of hydrogen chloride to hydrofluroalkane in a mixture hydrofluroalkane/hydrogen fluoride, shared how divided the I according to the invention, is not permanent. Hydrogen fluoride may be in excess relative to hydrofluroalkane in a mixture hydrofluroalkane/hydrogen fluoride shared by the method of separation according to the invention. The method of separation according to the invention is suitable in the case when hydrofluroalkane capable of combining with hydrogen fluoride azeotrope, or pseudoisotopy. The method of separation according to the invention is mainly applicable to the mixture hydrofluroalkane/hydrogen fluoride with azeotropic or near azeotropic composition.

The method of separation according to the invention is successfully applicable for the separation of a mixture containing 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and hydrogen fluoride.

At a pressure of 3 bar, the composition of the azeotropic mixture of hydrogen fluoride/1,1,1,3,3-pentafluorobutane is expressed approximately as a 60/40 by weight, i.e. the molar ratio of hydrogen fluoride to 1,1,1,3,3-pentafluorobutane is about 11/1.

In the preferred form of the invention, the separation of a mixture containing 1,1,1,3,3-pentafluorobutane and hydrogen fluoride produced by the interaction of a mixture of 1,1,1,3,3-pentafluorobutane/hydrogen fluoride with the predecessor 1,1,1,3,3-pentafluorobutane, preferably 1,1,1,3,3-pentachlorobutane, in the absence of catalyst. 1,1,1,3,3-Pentachlorobutane can be obtained, for example, telomerization chlorine-containing compounds, such, for example the EP, as 2-chloropropane with carbon tetrachloride or such as vinylidenechloride with 1,1,1-trichloroethane in the presence of various catalysts, such as, in particular, as PENTACARBONYL iron or copper salt in combination with any amine.

The mixture hydrofluroalkane/hydrogen fluoride and the organic compound used in the method of separation according to the invention in such proportions that the molar ratio of hydrogen fluoride to organic compound is usually at least 0.5. Primarily working with molar ratio of hydrogen fluoride to organic connection not less than 1. Even more preferably to operate at a molar ratio of hydrogen fluoride to organic compound is not less than 3 and most preferably in a molar ratio of at least 5. Usually used in a molar ratio of hydrogen fluoride to organic compound is less than 15 and preferably does not exceed 10.

The temperature at which interact between the mixture hydrofluroalkane/hydrogen fluoride and an organic compound, usually not below 60°C. Mainly, this temperature is at least 80°C. typically, the temperature does not exceed 160°and preferably does not exceed 140°C.

The interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound in the method section is to be placed according to the invention is carried out mainly in the liquid phase. In this case, the pressure is selected so that the reaction medium was in a liquid state. Pressure to be applied varies depending on the temperature of the reaction medium. As a rule, it is less than or equal to 40 bar. Mostly it is below or equal to 35 bar and most preferably less than or equal to 25 bar. Typically, the pressure is higher than or equal to 5 bar and preferably greater than or equal to 10 bar.

The method of separation according to the invention can be carried out in batch or continuous mode.

When the method of separation according to the invention is carried out in periodic mode, the duration of interaction between the mixture hydrofluroalkane/hydrogen fluoride and an organic compound is generally from 10 minutes to 5 hours. Mainly the duration of the interaction is equal to at least 0.5 hour and preferably for at least 1 hour. Typically, this duration does not exceed 4 hours and preferably does not exceed 2.5 hours.

When the method of separation according to the invention is carried out in continuous mode, the residence time of reactant in the reactor, usually not less than 0.5 hour. Usually it does not exceed 30 hours. Most often it ranges from 5 to 25 hours, and preferably in the range from 10 to 20 hours. Under the residence time of reactant in the reactor is meant the ratio of the volume of p is the promotional environment to the flow rate of the reaction medium at the reactor exit.

In the case when hydrofluroalkane is 1,1,1,3,3-pentafluorobutane, and organic compound 1,1,1,3,3-pentachlorobutane, good results were obtained when the molar ratio of hydrogen fluoride to 1,1,1,3,3-pentachlorobutane below 15, mainly in the range from 5 to 10, at the reaction temperature varying in the range from 80 to 140°mainly from 110 to 120°C, a pressure of from 5 to 40 bar, mostly from 15 to 25 bar, and the residence time of reactant in the reactor is from 0.5 to 25 hours.

The interaction between the mixture hydrofluroalkane/hydrogen fluoride and the organic compound in the method of separation according to the invention can be carried out in any reactor made of a material resistant to the temperature, pressure and used reactive substances, in particular to hydrogen fluoride.

Suitable continuous removal of the whole amount or the part formed by the reaction of hydrogen chloride. As a rule, remove at least 80% hydrogen chloride.

In a preferred variant of the method according to the invention the mixture of reaction products obtained by the reaction mixture hydrofluroalkane/hydrogen fluoride with at least one organic compound that can react with hydrogen fluoride, then subjected to at least one stage of processing to identify hydrofluroalkane. Note the Rami used types of processing, among others, are types of processing, used to separate hydrofluroalkane from residual hydrogen fluoride, such as solid-phase adsorption, such as NaF, washing with water, the operation of extraction, separation on a suitable membrane, extractive distillation or at least distillation. Of these types of treatment good results gave distillation.

In one embodiment, uses a three-stage distillation. The first stage distillation (I) is used to obtain at least one fraction containing residual hydrogen fluoride. The second stage distillation (II) is used to obtain at least one fraction containing non-volatile impurities. The third stage distillation (III) is used to obtain at least one fraction comprising substantially pure hydrofluroalkane. Can be applied to the entire sequence of these distillations, which gives a satisfactory result of the division and allows you to allocate at least one fraction containing substantially pure hydrofluroalkane. Good results were based on the sequence in which first there is the stage I and stage III, and then stage II.

When one of the specific forms of the invention, the latter is a method of separating a mixture containing at least one hydrofluroalkane and hydrogen fluoride, the situation of the speaker in their interactions mentioned mixture with at least one chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane followed by separation hydrofluroalkane with low content hydrogen fluoride, and the mixture of reaction products is preferably subjected to at least one distillation.

In a variant of the method of separation according to the invention is carried out in the absence of catalyst, the reaction mixture is preferably away from the reactor in the liquid state and then subjected to at least one stage of distillation.

The aim of the present invention is also a method of obtaining hydrofluroalkane on the basis of chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane and hydrogen fluoride.

Thus, the invention relates to a method for hydrofluroalkane, according to which the first reaction stage, at least one of chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane enter into interaction with hydrogen fluoride, and in the next stage of the reaction is injected into the interaction with hydrogen fluoride at least part of the product formed in the first reaction stage, and one of the reaction stages may include a method of separation according to the invention.

Typically, in the method of separation according to the invention hydrofluroalkane is formed in the first and subsequent stages of the reaction. Usually the degree of transformation in hydrofluroalkane aggregate used chlorine or chlorine - and fluorine-containing predestin is of ISR support in each stage at the level of at least 5 mol.%, often at the level of at least 10 mol.%, preferably not less than 20 mol.% and most preferably at least 50 mol.%.

The degree of conversion in hydrofluroalkane aggregate used chlorine or chlorine - and fluorine-containing precursors in the first and subsequent stages of the reaction mainly various. In this case, usually the degree of conversion in the first stage support, as described above, and the second degree of conversion in a subsequent stage support higher. Usually this second degree of transformation in hydrofluroalkane aggregate used chlorine or chlorine - and fluorine-containing precursors is at least 70 and preferably at least 90 mol.%.

As a rule, the content of hydrogen fluoride in the reaction medium in the first and subsequent stages of the reaction is different. Usually this content below in the first reaction stage and higher in the later stage.

As a rule, the content of hydrogen fluoride in the reaction medium in the first reaction stage is at least 5 wt.% Mostly this content is not lower than 10 wt.% Usually it does not exceed 20 wt.% and preferably does not exceed 15 wt.%

As a rule, the content of hydrogen fluoride in the reaction medium in the subsequent reaction stage is at least 40 wt.%. Mainly it is the content not less than 60 wt.%. It is to rule, it does not exceed 75% and preferably not exceed 70 wt.%.

The method of obtaining may include catalytic reaction stage and/or stage of the reaction conducted in the absence of catalyst. In one embodiment, which is preferred, method of production according to the invention includes at least one step of the reaction conducted in the absence of catalyst, and at least one catalytic step of the reaction.

In the following description, for simplification, we are talking only about this preferred variant of the method of receiving according to the invention, without limiting, however, the scope of the invention only that the preferred option.

As regards the reaction conducted in the absence of catalyst, the preferred reaction conditions correspond to the conditions described above for the interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound in the allocation method according to the invention.

Both stages of the reaction is mainly carried out in the liquid phase, and the mixture hydrofluroalkane/hydrogen fluoride in the catalytic stage is directed to a gaseous form, most often in the form azeotropic compositions.

Hydrofluroalkane, which can be obtained using the method of receiving according to the invention are the same as above hydrofluroalkane, which can be separated from their mixtures is hydrogen fluoride using the method of separation according to the invention.

Chlorine or chlorine - and fluorine-containing precursors suitable for use in catalytic and non-catalytic stages of the reaction method of obtaining hydrofluroalkane according to the invention are the same as the above chlorine-containing or chlorine - and fluorine-containing precursors suitable for use in the method of separation according to the invention. Chlorine or chlorine - and fluorine-containing precursor used in the catalytic reaction stage, mainly contains a mixture chlorpheniramine intermediates formed in the non-catalytic reaction stages in the interaction of at least part of the hydrogen fluoride mixture hydrofluroalkane/hydrogen fluoride with chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane, resulting in a non-catalytic reaction stage of the method of obtaining corresponds to the reaction of the above-described method of separation according to the invention.

Various stages of processing, suitable for use in the method of separation according to the invention are also applicable to this method of obtaining hydrofluroalkane.

The method of receiving according to the invention is particularly effective for obtaining 1,1,1,3,3-pentafluorobutane.

When the method of receiving according to the invention is used to produce 1,1,1,3,3-pentafluorobutane, the predecessor hydrocoral the Ana, used in the catalytic reaction stage may be 1,1,1,3,3-pentachlorobutane, the mixture chlorpheniramine intermediates or the mixture of these products with 1,1,1,3,3-pentachlorobutane. Chlorpheniramine intermediates formed in the non-catalytic reaction stage of the method are mainly the isomers of HCFC-363 and HCFC-364, i.e. isomers 1,1-dichloro-1,3 .3m-triptorelin (HCFC-363kfc), 1,3-dichloro-1,1,3-triptorelin (HCFC-363lfb), 3,3-dichloro-1,1,1-triptorelin (HCFC-363mfa), 1-chloro-1,1,3,3-Tetrafluoroethane (HCFC-364lfc) or 3-chloro-1,1,1,3-Tetrafluoroethane (HCFC-364mfb) or a mixture of these compounds.

Other possible present intermediates are (hydro)chlorine(fluorine)butenes, such as 1,1-dichloro-1,3-deverbal-2-ene and/or 1-chloro-1,1,3-triflorum-2-ene.

When the method of receiving according to the invention is used to produce 1,1,1,3,3-pentafluorobutane, the predecessor hydrofluroalkane used in non-catalytic reaction stage, is mainly 1,1,1,3,3-pentachlorobutane.

As a catalyst for the reaction of catalytic reaction stage of the method of obtaining hydrofluroalkane according to the invention can be, for example, used catalysts mentioned above as catalysts suitable for the method of separation according to the invention.

The amount of catalyst used in the catalytic reaction stage of the method of obtaining hydrofluroalkane according to the invention, the can is t to vary within wide limits. Usually it is not less than 0.5 mol.%, mostly at least 2 mol.% and more preferably at least 5 mol.%. Most often it is not more than 30 mol.% and more preferably not more than 10 mol.%. In the catalytic reaction stage using hydrogen fluoride in an amount such that the molar ratio of hydrogen fluoride to chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane was, as a rule, not less than 3. Primarily working with molar ratio of at least 5. Most often, this molar ratio is less than 15 and preferably does not exceed 10.

The temperature at which interact in a catalytic reaction stage of the way is usually not lower than 60°C. Mainly, this temperature is at least 80°C. As a rule, it does not exceed 160°and preferably does not exceed 140°C.

The interaction of hydrogen fluoride with chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane in the catalytic reaction stage of the process is carried out predominantly in the liquid phase. In this case, the pressure is selected so that the reaction medium was in a liquid state. The pressure used for the reaction in the catalytic reaction stage of the method varies depending on the temperature of the reaction medium. As the rule is, it is less than or equal to 35 bar. Particularly advantageous application of pressure below or equal to 25 bar. Typically, the pressure is higher than or equal to 5 bar and preferably greater than or equal to 10 bar.

The catalytic reaction stage of the retrieval process according to the invention can be carried out in batch or continuous mode.

When the catalytic reaction stage of the method of receiving according to the invention is carried out in periodic mode, the duration of reaction generally ranges from 10 min to 5 hours. Mainly the duration of the reaction is equal to not less than 0.5 hour, and preferably for at least 1 hour. Typically, this duration does not exceed 4 hours and preferably does not exceed 2.5 hours.

When the catalytic reaction stage of the method of receiving according to the invention is carried out in continuous mode, the residence time of reactant in the reactor, usually not less than 0.5 hour. Usually it does not exceed 50 hours. Most often it ranges from 10 to 40 hours and preferably in the range from 10 to 30 hours.

When the method of receiving according to the invention is used to obtain 1,1,1,3,3-pentafluorobutane, the catalytic reaction is carried out mainly in the presence of titanium tetrachloride or tin tetrachloride is used as the catalyst, more preferably in the presence of titanium tetrachloride. Good results were the scientists at temperatures from 80 to 140° C, a pressure of from 10 to 25 bar and a residence time of reactant in the catalytic reactor is from 1 to 5 hours.

The reaction in the catalytic reaction stage of the method of receiving according to the invention can be carried out in any reactor made of a material resistant to the temperature, pressure and used reactive substances, in particular to hydrogen fluoride.

At the outlet of the catalytic reaction stage of the way away, mainly in the gas phase, a mixture of hydrogen chloride and hydrofluroalkane/hydrogen fluoride, which in some cases has azeotropic composition, the mixture is served on the non-catalytic step of the reaction method according to the invention, possibly after separation of the contained hydrogen chloride.

The preferred technique of the work consists in carrying out a catalytic reaction in the boiler-reactor under such temperature and pressure that the formed hydrogen chloride and hydrofluroalkane are gaseous, while reacting substances and other products of the reaction are generally in the liquid state. The boiler-reactor is mainly on the top of the distillation column for separation. In order to avoid accumulation in the reactor of non-volatile impurities and to maintain the activity of the catalyst reactor catalytic reaction stage of the way teleshop the knowledge to equip blowing.

The specific variant of the method of receiving according to the invention is a method of obtaining hydrofluroalkane, according to which the catalytic reaction stages interact with at least one chlorine or chlorine - and fluorine-containing precursor with hydrogen fluoride in the presence of a catalyst, and in the other, non-catalytic reaction stage, interact mixture hydrofluroalkane/hydrogen fluoride formed in the catalytic reaction stages, with at least one chlorine or chlorine - and fluorine-containing precursor according to the above method of separation according to the invention, and at least part of the chlorine or chlorine - and fluorine-containing precursor used in the catalytic stage, comes with non-catalytic stage.

When a catalyst is a compound of titanium, it is possible to synthesize hydrofluroalkane at one stage.

A third object of the invention relates to a catalytic process for the preparation hydrofluroalkane used as the catalytic reaction stage in the method according to the invention, in which the catalyst is a compound of titanium. Usually in the catalytic method according to the invention the reaction is conducted in the liquid phase, and the connection of the titanium halide is titanium, mainly the substantial titanium tetrachloride. The conditions described above for catalytic reaction stage of the method of obtaining applicable also to a catalytic method according to the invention. Catalytic method according to the invention is well applicable for the synthesis of hydrofluroalkane containing from 3 to 6 carbon atoms, such as 1,1,1,3,3-pentafluoropropane and 1,1,1,3,3-pentafluorobutane. Especially well suited for the synthesis of 1,1,1,3,3-pentafluorobutane, mostly in one stage, based on 1,1,1,3,3-pentachlorobutane.

The fourth object of the present invention relates to a method of synthesis hydrofluroalkane, according to which conduct liquid-phase interaction with hydrogen fluoride of at least one of chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane, characterized by the atomic ratio of F/Cl below 1, in a liquid medium, in which constant weight content, higher than or equal to 50% fluorinated or chlorpheniramine organic compounds whose average atomic ratio F/Cl is at least 1, mostly at least 1.2 and particularly preferably at least 1.5 times. The method of synthesis is mainly carried out on the basis of chlorinated predecessor hydrofluroalkane in the absence of a catalyst.

Under fluorinated and chlorpheniramine organic compounds, for the purposes of the present invented the I, refers, in particular, the target hydrofluroalkane and chlorpheniramine intermediates hydrofluroalkane. This may also include some side reaction products and/or some impurities introduced together with used in the synthesis of the precursor. The weight content of fluorinated and chlorpheniramine organic compounds in a liquid medium is predominantly not less than 70%. Particularly preferably, the content of at least 80%. Usually it is not more than 99 wt.% and mostly to 98.5 wt.%.

Working reaction conditions described for the method of separation according to the invention is directly applicable to the method of synthesis hydrofluroalkane. If you followed this method of synthesis hydrofluroalkane carry out stage distillation described for the method of separation according to the invention, the operating conditions in this case is preferably such that the reaction medium, which contains hydrogen fluoride in a quantity smaller compared to the amount in the azeotropic mixture hydrofluroalkane/hydrogen fluoride, take away in the form of a liquid phase.

This method is successfully applied for the synthesis of 1,1,1,3,3-pentafluorobutane of 1,1,1,3,3-pentachlorobutane.

When the method is used for the synthesis of 1,1,1,3,3-pentafluorobutane, mostly at least 50% of the liquid reaction medium are 1,1,1,3,3-pentaf arbutin and the isomers of the products of HCFC-363 and HCFC-364.

Called the method of synthesis has the advantage, due to the fact that the presence in the liquid reaction medium significant quantities of target hydrofluroalkane and his chlorpheniramine intermediates gives the environment a property of the solvent with respect to the mixture of hydrogen fluoride and chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane that allows you to increase the yield of the reaction, in particular because some moreaccessible chlorpheniramine intermediates that accumulate in the environment in the absence of hydrofluroalkane, apparently, are formed in the conditions of the synthesis method according to the invention in much more limited quantities.

The invention relates to azeotropic or pseudoesotropia compositions consisting mainly of 1,1,1,3,3-pentafluorobutane (from 1.5 up to 27.5 mol.%) and hydrogen fluoride (72,5 up to 98.5 mol.%).

From the point of view of the fundamental theory of thermodynamic state of the fluid is defined by four independent variables: pressure (P), temperature (T), the composition of the liquid phase (X) and the composition of the gaseous phase (Y). The true azeotrope is a special system of 2 or more components for which at a given temperature and a given pressure, the composition of the liquid phase, X) coincides with the composition of the gaseous phase Y. Pseudoesotropia it is the system of 2 or more components, for which at a given temperature and a given pressure, the composition of the liquid phase X to a large extent similar to the composition of the gaseous phase Y. in practice, this means that the components of such azeotropic and pseudoisotropic systems cannot be easily split using distillation.

Under pseudoesotropia mixture, for the purposes of the present invention, is meant a mixture of two components, the boiling point of which (at a given pressure) differs from the boiling point of the true azeotrope by a maximum of 0.5°C. the Preferred mixture, the boiling point which differs from the boiling point of the true azeotrope by a maximum of 0.2°C. a Particularly preferred mixture, the boiling point which differs from the boiling point of the true azeotrope by a maximum of 0.1°C.

1,1,1,3,3-Pentafluorobutane and hydrogen fluoride form a binary azeotrope or pseudoisotopy when the mixture contains from about 72,5 up to 98.5 mol.% hydrogen fluoride. At a pressure of 1 bar binary composition mainly consists of approximately 91-98,5 mol.% hydrogen fluoride and 1.5-9 mol.% 1,1,1,3,3-pentafluorobutane and has a boiling point of at least about 18°C. At a pressure of 10 bar binary composition mainly consists of approximately 78-85 mol.% hydrogen fluoride and 15 to 22 mol.% 1,1,1,3,3-pentafluorobutane and has a boiling point of at least about 90°C. At a pressure of 2 bar binary composition mainly consists of approximately 75-84 mol.% hydrogen fluoride and 16 to 25 mol.% 1,1,1,3,3-pentafluorobutane and has a boiling point of at least about 97° C.

Pronounced changes in the concentration of the components of the azeotrope with the pressure change is completely unexpected. Thus, it is possible, using the method according to the invention, to isolate substantially pure components of the azeotrope, and, depending on the pressure, azeotropic fraction enriched or hydrogen fluoride, or 1,1,1,3,3-pentafluorobutane.

The composition of the invention can be used, for example, for the purification of 1,1,1,3,3-pentafluorobutane. When there is a need in the purification of 1,1,1,3,3-pentafluorobutane containing impurities, which do not form an azeotrope with hydrogen fluoride or azeotrope with hydrogen fluoride has a boiling point that is significantly different from the boiling point of the compositions according to the invention, it is possible to use the composition for separating, on the one hand, 1,1,1,3,3-pentafluorobutane and hydrogen fluoride and, on the other hand, to separate the impurities. An example of such use is separating 1,1,1,3,3-pentafluorobutane and hydrogen fluoride from the reaction mixture obtained by the synthesis of 1,1,1,3,3-pentafluorobutane hydropericardium chlorine-containing precursor, for example, as described above. Used in this way, a preferred composition according to the invention, enriched 1,1,1,3,3-pentafluorobutane. Typically, the composition contains at least 10 mol.% 1,1,1,3,3-pendaftar Utena. Often the composition comprises at least 15 mol.% 1,1,1,3,3-pentafluorobutane. The preferred content of at least 20 mol.% 1,1,1,3,3-pentafluorobutane.

Figure 1-4 respectively illustrate specific embodiments of the method of separating a mixture containing at least one hydrofluroalkane and hydrogen fluoride, the method of obtaining hydrofluroalkane and azeotropic or pseudoisotropic compositions of the present invention.

Figure 1 illustrates a variant of the method of separation according to the invention, in which the interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound, which can be, in particular, chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane, is carried out in the absence of a catalyst.

On installation, the diagram of which is depicted in figure 1, taken from the reservoir (1) of chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane is introduced via line (2) into the reactor (5). Partial according to the invention the mixture hydrofluroalkane/hydrogen fluoride is fed from the tank (3) via line (4) into the reactor (5). In the reactor (5) hydrogen fluoride from a mixture hydrofluroalkane/hydrogen fluoride interacts with chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane with formation of a mixture of reaction products containing hidrofor is lkan, reduced the amount of hydrogen fluoride, hydrogen chloride, chlorine - and fluorine-containing intermediates, possibly unreacted chlorine or chlorine - and fluorine-containing precursor and the non-volatile impurities. Hydrogen chloride is directed to a gaseous form from the mixture of reaction products through a line (6), separated from the other possible captured the reaction products in the separator (7) and output via line (8). Other possible captured the reaction products are returned to the reactor (5) via line (9).

A mixture of other reaction products are directed to a liquid state through line (10) on stage distillation (11). At the head of the distillation column (12) select mixture containing hydrofluroalkane and hydrogen fluoride, which may be returned to the reactor (5) via line (12). In the lower part of the column (13) receive the mixture of products containing mainly hydrofluroalkane, chlorine - and fluorine-containing intermediates hydrofluroalkane possibly unreacted precursor and non-volatile impurities.

Figure 2 illustrates a variant of the method of separation according to the invention, in which the interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound, which can be, in particular, chlorine or chlorine - and fluorine-containing precursor hydrofluroalkane, is carried out in the presence of a catalyst. Part of this mouth is ovci, identical parts of the installation shown in figure 1, are denoted by the same numbers. The description of these parts will not be repeated.

In this embodiment, the reaction products were taken to the gaseous state through line (14) and sent to a separator (15). Hydrogen chloride divert via line (16). Other reaction products are sent via line (17) on stage distillation (11). At the head of the distillation column (12) select mixture containing hydrofluroalkane and hydrogen fluoride, which may be returned to the reactor (5) via line (12). In the lower part of the column (13) receive the mixture of products containing mainly hydrofluroalkane, chlorine - and fluorine-containing intermediates hydrofluroalkane possibly unreacted precursor and non-volatile impurities.

In order to avoid accumulation of non-volatile impurities in the reactor (5) and to maintain the catalyst activity, the reactor (5) equip the purge (18).

The method of obtaining hydrofluroalkane in two stages of the reaction according to the invention is illustrated by the reaction scheme shown in figure 3.

Part of this setup is identical to the installation parts shown in figure 1, are denoted by the same numbers. The description of these parts will not be repeated.

Taken through line (13) the mixture of products containing mainly hydrofluroalkane, chlorine - and fluorine-containing intermediates hydrofluroalkane possibly unreacted precursor and non-volatile impurities, sent for distillation (19). At the head of the distillation column (20) is taken substantially pure hydrofluroalkane. In the lower part of the column (21) to obtain a mixture containing hydrofluroalkane, chlorine - and fluorine-containing intermediates hydrofluroalkane, non-volatile impurities and possibly unreacted precursor, which is sent to the third distillation (22).

At the head of the distillation column (23) select mixture containing hydrofluroalkane, chlorine - and fluorine-containing intermediates hydrofluroalkane and possibly unreacted precursor. In the lower part of the column (24) receive non-volatile impurities, which are removed from the installation.

The mixture of products selected in the head of the column (22)is sent to a catalytic reactor (25) via line (23). In addition, in contrast to the setup depicted in figure 1, the mixture hydrofluroalkane and hydrogen fluoride taken in the head of the column (11)is also sent to the reactor (25) via line (26).

In the reactor (25), in which the catalyst is fed through line (28) is taken away from the tank (27) hydrogen fluoride. In the reactor (25) hydrogen fluoride interacts with the products from the column (22). The mixture hydrofluroalkane/fluoride hydrogen chloride hydrogen away from the reactor (25) in a gaseous state through line (29) and sent to a separator (30). The mixture hydrofluroalkane/FPO the East hydrogen chloride hydrogen is directed through line (31) into the reactor (5). Other reaction products are returned to the reactor (25) through line (32).

In order to avoid accumulation of non-volatile impurities in the reactor and to maintain the catalyst activity, the reactor (25) equipped with a purge (33).

The following examples illustrate the present invention without limiting its scope.

In the example below, 1 the degree of transformation (SP) 1,1,1,3,3-pentachlorobutane (RSV) is expressed as the percentage of the ratio of the input to the process number minus neprevyshenie (unreacted) number to put into the process number.

Example 1

Example 1 was carried out at the facility in accordance with figure 1.

A 0.5-liter reactor made of stainless steel, blade equipped with a mechanical stirrer, a temperature sensor and immersion, allowing you to take samples of the liquid phase during the test, load 5,02 mol of hydrogen fluoride in a mixture of azeotrope composition containing 0.475 mol 1,1,1,3,3-pentafluorobutane (molar ratio HF/1,1,1,3,3-pentafluorobutane equal to 10.6) and 0,739 mol 1,1,1,3,3-pentachlorobutane. After that, the reactor was immersed in a thermostatted bath and under continuous stirring maintain the temperature of 120°C. regulate Pressure at 25 bar. The selection is carried out after 1, 3 and 30 h of reaction. The results collected in the table below. The degree into which I used in the reaction of 1,1,1,3,3-pentachlorobutane between 1 and 30 hours of reaction, respectively, ranged from 94 to 100 mol.%. The molar ratio HF/1,1,1,3,3-pentafluorobutane between 1 and 30 hours of reaction, respectively, decreased from 6 to 1.8. Specify the number of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and chlorpheniramine intermediates (HCFC-361, -362, -363 -364 and)present in the reaction medium after a number of samples.

The duration of reaction, h1330
JV RSA, %94>to 99.9100
The amount of HCFC-365mfc, mol (reaction medium)0,510,640,99
The amount of HCFC-364, mol (reaction medium)0,300,350,074
The amount of HCFC-363, mol (reaction medium)0,090,130,10
The amount of HCFC-362, mol (reaction medium)0,160,04<0,007
The amount of HCFC-361, mol (reaction medium)0,007<0,007<0,007
Consumed HF, mol1,942,703,20
The remaining HF, molis 3.082,301,80
HF/HFC-365mfc, mol/mol6,03,61,8

Example 2

In the same reactor as in example 1, load 5.0 mol of hydrogen fluoride and 0,053 mol of titanium tetrachloride. After that, the reactor was immersed in a thermostatted bath and under continuous stirring maintain the temperature 135°C. Pressure regulates at the level of 25 bar. Into the reactor continuously serves 0.1 mol/h 1,1,1,3,3-pentachlorobutane and 1 mol/h of hydrogen fluoride. The reactor continuously Tegaserod so that the level of the reaction mixture in the reactor remained almost constant. The number of 1,1,1,3,3-pentafluorobutane in the output gases corresponded to exit 97% (based on the entered 1,1,1,3,3-pentachlorobutane.

The reaction under these conditions was carried out for 30 hours and output remained constant.

The output gases were a mixture of hydrogen fluoride/1,1,1,3,3-pentafluorobutane a molar ratio close to 5/1, which could be used in the method of separation according to the invention.

Examples 3-5 in figure 4 represent the vapor-liquid equilibrium for the binary compositions of 1,1,1,3,3-pentafluorobutane with hydrogen fluoride at three different pressure values x HF denotes the molar concentration of hydrogen fluoride in the liquid phase, and HF denotes the molar concentration of hydrogen fluoride in the gas phase. The data on which are based the curves were obtained by calculation using a computer etc the program Aspen Plus® company Aspen Tech® on the basis of measured and calculated thermodynamic properties of mixtures of 1,1,1,3,3-pentafluorobutane with hydrogen fluoride. Example 3 is given by the curves corresponding to the pressure of 1 bar. Example 4 is given by the curves corresponding to a pressure of 10 bar. Example 5 is given by the curves corresponding to a pressure of 15 bar.

1. Method of separating a mixture containing at least one hydrofluroalkane and hydrogen fluoride, whereby the mixture hydrofluroalkane/hydrogen fluoride is injected into the interaction in the absence of catalyst with at least one organic compound that can react with hydrogen fluoride.

2. The method of separation according to claim 1, in which the organic compound is chlorine or chlorine - and fluorine-containing organic compound, mainly connecting the predecessor hydrofluroalkane.

3. The method of separation according to claim 1 or 2, in which the interaction between the mixture hydrofluroalkane/hydrogen fluoride and the organic compound is carried out in the liquid phase.

4. The method of separation according to claim 3, in which the reaction mixture after the interaction of the mixture hydrofluroalkane/hydrogen fluoride with an organic compound disperses in the liquid phase.

5. The method of separation according to any one of claims 1 to 4, in which hydrofluroalkane has the ability to form water with fluoride is Odom azeotrope or pseudoisotopy.

6. The method of separation according to any one of claims 1 to 5, in which the mixture of the reaction product is subjected to at least one of the subsequent processing stages, designed to highlight hydrofluroalkane.

7. The method according to any one of claims 1 to 6, in which hydrofluroalkane contains 3 to 6 carbon atoms.

8. The method according to any one of claims 1 to 7, in which hydrofluroalkane is 1,1,1,3,3-pentafluorobutane.

9. The method of obtaining hydrofluroalkane, according to which the first reaction stage, at least one of chlorine or chlorine - and fluorine-containing precursor is injected into the interaction with hydrogen fluoride, and in one of the subsequent stages is injected into the interaction with hydrogen fluoride at least part of the product formed in the first stage, and one of the reaction stages includes a method of separation according to any one of claims 1 to 8.

10. The method according to claim 9, in which hydrofluroalkane is formed in the first and second stages of the reaction.

11. The method according to claim 9 or 10, comprising at least one catalytic step of the reaction.

12. The method according to claim 11, in which the catalytic step of the reaction is carried out in the liquid phase and the catalyst is a titanium halide, preferably titanium tetrachloride.

13. The method according to any of PP-12, in which hydrofluroalkane contains 3 to 6 carbon atoms.

14. The method according to any of PP-13, in which hydrofluroalkane what is 1,1,1,3,3-pentafluorobutane.

15. Azeotropic or pseudoesotropia composition suitable for the purification of 1,1,1,3,3-pentafluorobutane, characterized in that the composition consists essentially of 1,5-of 27.5 mol.% 1,1,1,3,3-pentafluorobutane and from 72,5-to 98.5 mol.% hydrogen fluoride.

16. The composition according to item 15, containing hydrogen fluoride and 1,1,1,3,3-pentafluorobutane when the molar ratio of hydrogen fluoride:1,1,1,3,3-pentafluorobutane about 11 at a pressure of 3 bar.



 

Same patents:

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, 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: 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

The invention relates to compositions containing 1,1,1,3,3-pentafluorobutane

The invention relates to a method, which allows to obtain high yields of very pure СНF2-CF3(HFC 125) penaflorida

The invention relates to the production of freon and/or OCTAFLUOROPROPANE, which is used as a mixed refrigerant gas dielectrics, reagents dry etching of semiconductor materials, laser working media

The invention relates to the production of perfluorinated organic compounds used in medicine, electronics, electrical engineering, textile and chemical industries

The invention relates to chemical technology, namely the production 1,1,2,2,3,3,3-Heptafluoropropane used as a component of mixed refrigerants, gas dielectric propellant combustion inhibitor

The invention relates to mixtures of halogenated hydrocarbon compounds having a low potential for depletion of the ozone layer of the atmosphere

The invention relates to chemical technology, namely the production of perchloromethane, specifically diperchlorate (Halocarbon 22, R22, HCFC 22), used as ozone-safe refrigerant, propellant, the pore-forming raw materials to obtain formononetin

FIELD: method for separation of fluorine-containing product mixture, in particular mixtures containing nitrogen trifluoride and tetrafluoromethan.

SUBSTANCE: purification of nitrogen trifluoride from tetrafluoromethan is carried out by nitrogen trifluoride absorption using as absorbent solvent inert to nitrogen trifluoride and wherein nitrogen trifluoride solubility is more than the same of tetrafluoromethan, under absorbent consumption and pressure sufficient to nitrogen trifluoride absorption, followed by nitrogen trifluoride desorption. As inert solution halogenated or perhalogenated compounds are used. Solution is fed into absorber under upper pressure, and absorption and following desorption steps are repeated. Part of purified nitrogen trifluoride, recovered on desorption step, is recycled into absorption step to dilute starting product contaminated with tetrafluoromethan.

EFFECT: nitrogen trifluoride of high purity with minimum losses of target product.

6 cl, 7 ex, 7 tbl, 3 dwg

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: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluorocyclobutane. Method is carried out by interaction of crude octafluorocyclobutane containing impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that is able to eliminate indicated impurities up to the content less 0.0001 wt.-% from the mentioned crude octafluorocyclobutane. 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. Impurity represents at least one fluorocarbon taken among the group consisting of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetrafluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, hexafluoropropene and 1H-heptafluoropropane. Adsorbent represents at least one of representatives taken among the group including activated carbon, carbon molecular sieves and activated coal. Crude octafluorocyclobutane interacts with the mentioned impurity-decomposing agent at temperature from 250oC to 380oC. Invention proposes gas, etching gas and purifying gas including octafluorocyclobutane with purity degree 99.9999 wt.-% and above and comprising fluorocarbon impurity in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluorocyclobutane.

EFFECT: improved purifying method.

26 cl, 13 tbl, 10 ex

FIELD: industrial organic synthesis.

SUBSTANCE: hexafluorobuta-1,3-diene, suitable as bifunctional monomer in production and cross-linking of perfluorinated elastomers but also as agent for dry plasma etching in manufacture of semiconductor articles, is first subjected to low-temperature rectification and then additionally purified on zeolite sorbents and submitted to vacuum degassing and filtration. Low-temperature rectification is carried out in two steps: first at overpressure in column from 1.0 atm to 0.05 atm and still temperature 15-25оС, and then, respectively, 0.3 to 0.2 atm and 15-25оС. After first or second low-temperature rectification step product additionally undergoes cleaning on carbon sorbents.

EFFECT: simplified process technology.

5 cl, 2 tbl, 5 ex

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

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

The invention relates to the disposal of PCBs, in particular capacitor dielectric liquid Sovtol-10, and can be effectively used in chemical and electrochemical industry

The invention relates to the neutralization of toxic substances, which are a mixture of polychlorobenzenes and PCBs, called sovtol

The invention relates to cleaning and getting 1,1-dottorato, which is used for foaming plastics or as a propellant in aerosols

The invention relates to the cleaning of TETRAFLUOROMETHANE, which is used as a gas for etching or cleaning gas in the production of semiconductor devices

FIELD: organic chemistry, in particular difluorochloromethane useful as cooling agent, propellant, blowing agent, as well as in fluoromonomers production.

SUBSTANCE: chloroform is treated with hydrogen fluoride in presence of catalyst predissolved in chloroform with concentration of 20-30 mol.% and chlorine, at temperature of 60-110°C and pressure of 7013 atm. As catalyst mixture of antimony pentachloride, fluorotetrachloride and trichloride in ratio of 1:(0.03-0.15):(0.03-0.15), respectively is used. Process is carried out under continuous controlling reaction mass electrical resistance which is maintained in limits of 600-1600 Om. Chlorine is introduced in amount of 0.01-0.3 mass % with respect to chloroform. Method of present invention makes it possible to control synthesis parameters in dependence of reaction mass electrical resistance.

EFFECT: increased process selectivity; new catalyst.

5 cl, 4 ex

Up!