KR100255872B1 - Fluorination catalyst and process - Google Patents

Abstract

The present invention relates to a chromium-free fluorination catalyst consisting of an activated amount of zinc supported on an alumina, halogenated alumina or aluminum oxyhalide support.

Description

Fluorination Catalysts and Fluorination Methods

The present invention relates to an improved fluorinated catalyst and to a process for producing fluorinated hydrocarbons by catalysis of hydrogen fluoride with hydrocarbons and halogenated hydrocarbons. Specifically, the present invention relates to catalyzed alumina, halogenated alumina or aluminum oxyhalide catalysts and, in a specific embodiment, 1,1 by catalysis of hydrogen fluoride and 1-chloro-2,2,2-trifluoroethane. It relates to a process for producing 1,2-tetrafluoroethane.

Processes for the production of fluorinated hydrocarbons obtained by catalytic vapor phase fluorination of hydrogen fluoride and hydrocarbons and halogenated hydrocarbons and which may contain halogen atoms other than fluorine are well known and numerous catalysts used in these methods have been proposed. Has been. Catalysts comprising or based on chromium, in particular chromia, have been frequently used in the above known processes. Furthermore, methods have also been proposed for promoting the activity of catalysts by incorporating such chromium-containing catalysts, for example, metals such as zinc, nickel, cobalt and manganese in an activity-promoting amount.

Thus, for example, chromia or halogenated chromia are vapor phases of hydrogen fluoride and trichloroethylene for producing 1-chloro-2,2,2-trifluoroethane as described in British Patent No. 1,307,224. Of hydrogen fluoride and 1-chloro-2,2,2-trifluoroethane to prepare 1,1,1,2-tetrafluoroethane, which may be used for the reaction and described in British Patent No. 1,589,924. It can be used for vapor phase reactions. This same catalyst may be used for the fluorination of 1-chloro-2,2,2-trifluoroethane of chlorodifluoroethane. British Patent No. 1,589,924 describes a method for removing impurities from 1,1,1,2-tetrafluoroethane by reacting hydrogen fluoride with chlorodifluoroethylene impurities.

The catalysts may also comprise chromium on metal oxides such as alumina or magnesia, halogenated oxides or oxyfluoride supports, for example, during the fluorination process in which these catalysts are used, chromium is chromia, halogenated chromia or chromium. Will be converted to oxyfluoride. Now, it has been found that even if chromium is not present, the supports alone exhibit minimal catalytic activity and some supports may exhibit significant activity by incorporating an activity promoting amount of zinc.

According to the present invention, the present invention provides a chromium-free fluorination catalyst composed of an activated amount of zinc, or a zinc compound supported on an alumina, halogenated alumina or aluminum oxyhalide support.

According to the invention the invention also provides a process for producing fluorinated hydrocarbons consisting of reacting hydrocarbons or halogenated hydrocarbons with hydrogen fluoride in the vapor phase in the presence of the fluorination catalyst described above.

The amount of zinc incorporated in the catalyst is sufficient to promote the activity of the alumina, halogenated alumina or aluminum oxyhalide incorporating the zinc promoter. Compared with the catalytic activity when the optimum amount of zinc promoter is incorporated, too much zinc promoter can reduce the catalyst activity rather than increase it, and the optimal amount of zinc occurs only when the amount of zinc promoter is present. It is important.

The amount of zinc promoter incorporated into the catalyst to obtain significant activation will depend on the surface support of the underlying support used, in particular on the support and on the method used to prepare the modified catalyst. However, for certain specific supports and catalyst preparation methods, the optimal amount of zinc promoter is readily determined by simple route tests. Consequently, the amount of zinc ranges from about 0.5 to about 30 weight percent of the catalyst, preferably from about 1.5 to about 25 weight percent.

The optimum amount of zinc incorporated depends on the surface area of the catalyst, in particular the “surface active area of the catalyst”. The working surface area of the catalyst is the surface area of the catalyst measured after the catalyst has been prepared and pretreated with hydrogen fluoride (as described below) or in the vapor phase fluorination reaction where hydrogen fluoride is used unless the catalyst is pretreated with hydrogen fluoride. Refers to the surface area of the catalyst measured after using the catalyst. The working surface area of the catalyst will range from about 10-about 100 m 2 / g, generally about 10-about 50 m 2 / g. When preparing a catalyst from alumina, a catalyst having a working surface area within the specified range is obtained from alumina having a surface area of about 50 to about 400 m 2 / g after preparation and pretreatment. The catalyst may be prepared from alumina having a surface area of about 50-about 250 m 2 / g, preferably about 150-about 250 m 2 / g as starting material.

As described above, the amount of promoter incorporated in the catalyst also depends on the catalyst preparation method used. The effective site of the catalyst is thought to be the surface of the support containing the zinc promoter cation located in the alumina, halogenated alumina or aluminum oxyhalide lattice and the amount of this surface zinc promoter is the amount that determines the catalytic activity. In general, catalysts prepared by other methods and prepared by impregnation rather than catalysts containing zinc promoter in non-surface positions have a greater effect of promoting the activity of zinc promoter per unit weight of zinc promoter.

For example, when zinc is incorporated onto the alumina support by impregnation using a catalyst producing alumina having a surface area of 180 m 2 / g, the amount of zinc is about 0.5 to about 10% by weight of the catalyst, preferably about Optimal activation occurs when it is within the range of 0.5- about 6% by weight, more preferably about 1.5- about 4% by weight, especially about 1.5- about 3.5%; Compared to the activity promotion obtained by zinc in the optimum range, when zinc is about 8% by weight or more, no further effect can be exerted for promoting catalyst activity, while less than 0.5% by weight will be insufficient to promote catalytic activity to a considerable extent. In contrast, for catalysts prepared by coprecipitation, the amount of zinc in the case where a significant amount of zinc is incorporated in a non-surface position is about 3 to about 30 weight percent of the catalyst, preferably about 4 to about 25 weight %, Especially about 5- about 15% by weight.

At least to some extent, depending on the catalyst preparation technique, the zinc promoter will be incorporated into the catalyst, for example in the form of compounds such as halides, oxhalides, oxides, or hydroxides. When the catalyst is prepared by impregnation of aluminum oxide, halogenated aluminum oxide or aluminum oxyhalide support, the compound is preferably a water-soluble salt such as, for example, a halide, nitrate or acetate and used in the form of an aqueous solution thereof. . The hydroxides of the promoter and the aluminum may be co-precipitated and then converted into oxides to produce a catalyst. Another method of preparing the catalyst is by mixing and milling the base catalyst with an insoluble zinc compound. A method for preparing a catalyst based on aluminum oxyhalide is to add an accelerator compound to hydrated aluminum fluoride and calcinate the mixture.

The zinc-promoted catalyst preparation of the present invention will employ any of the methods described above or any other method.

The fluorination catalyst will usually be subjected to a prefluorination treatment with hydrogen fluoride and optionally an inert diluent before the fluorination reaction is used for catalysis. Typical pretreatment procedures consist of heating the catalyst from 250 ° C. to 450 ° C. under contact with hydrogen fluoride or a mixture of hydrogen fluoride and air. Eventually the action catalyst is believed to be at least partially zinc fluoride supported on fluorinated alumina or aluminum oxyfluoride.

The catalyst will be used in the form of pellets or granules of suitable size for fixed or fluidized beds. It may be periodically regenerated or reactivated by heating in air at a temperature of about 300-about 500 ° C. The air is used either as a mixture with an inert gas such as nitrogen or as a mixture with hydrogen fluoride which exits hot in the catalytic treatment process and may be used directly in the vapor phase fluorination process.

The activity of the base (unpromoted) alumina, halogenated alumina or aluminum oxy halide catalyst is enhanced by incorporation with an accelerator. The selectivity of the catalyzed reaction from the 1-chloro-2,2,2-trifluoroethane and hydrogen fluoride with said catalyst towards the direction of 1,1,1,2-tetrafluoroethane is generally at least 85 The same as when using this non-catalyzed catalyst which is more than%.

If necessary, the catalyst may contain one or more other metals besides zinc, for example nickel, copper, manganese, cobalt and iron, and catalyst activity may be restored by regenerating the catalyst when one or more of iron, cobalt and copper is present. Particularly preferred are these metals, as they enhance the activity to the extent possible. At particularly preferred zinc addition amounts, we generally use only zinc or only a small amount of zinc, namely less than 2.0% by weight, preferably less than 1.5% by weight, in particular less than 1.0% by weight, of which at least most are zinc. I prefer to be However, if the catalyst is composed of relatively high zinc loadings of at least about 3% by weight, preferably at least about 4% by weight, in particular at least about 5% by weight, for example when the catalyst is prepared by impregnation, we In addition it is preferred to incorporate small amounts of iron, for example in the range of about 0.1 to about 2% by weight of the catalyst, preferably about 0.1 to about 1.5% by weight, more preferably about 0.5 to about 1.5% by weight. The ratio of zinc to iron (wt% based on the weight of the catalyst) is preferably about 80: 1-about 2: 1, more preferably about 16: 1- about 2: 1. This ratio is preferably independent of the absolute amounts of zinc and iron in the catalyst.

Thus, for example, in catalysts prepared by methods such as coprecipitation, in which significant amounts of zinc and iron are incorporated into the catalyst at non-surface positions, for example at least 6% by weight of the catalyst, preferably at least 10% by weight of zinc, Relative amounts of zinc and iron (wt based on the weight of the catalyst), even if the absolute amount of zinc and iron is high, such as the amount of iron in the range of about 0.2 to about 12%, preferably about 0.4 to about 4.5%, by weight of the catalyst. %%) is preferably also within the range given above.

Another aspect of the invention is a method of using an accelerated catalyst in a fluorination process consisting of reacting hydrogen fluoride with a hydrocarbon or halogenated hydrocarbon in the vapor phase.

Alkenes (unsaturated hydrocarbons) In particular halogenated alkenes (eg trichloroethylene) or preferably halogenated alkanes of C _1-4 containing at least one chlorine will be fluorinated and as examples of specific fluorination reactions that can be carried out. Prepared 1,1,1,2-tetrafluoroethane from 1-chloro-2,2,2-trifluoroethane, prepared 1-chloro-2,2,2-trifluoroethane from trichloroethylene, and There is a conversion of 1-chloro-2,2-difluoroethylene to 1-chloro-2,2,2-trifluoroethane. Examples of other fluorination reactions in which the catalysts have been usefully employed include dichlorotrifluoroethane 123, chlorotetrafluoroethane 124 and / or pentafluoroethane by reaction of hydrogen fluoride with perchloroethylene in the vapor phase. 125) Preparation and preparation of trichlorotrifluoroethane 113, dichlorotetrafluoroethane (114 / 114a) and / or chloropentafluoroethane 115 by reaction of chlorine and hydrogen fluoride with perchloroethylene in vapor phase There is.

The fluorination reaction conditions used are known to be convenient conditions for the use of chromia or halogenated chromia as catalysts, e.g. temperatures in the range of 180 to about 500 DEG C, depending on the specific fluorination reaction carried out, Hydrogen fluoride and atmospheric or overpressure.

However, due to the increased activity of the catalyzed catalyst, the reaction is carried out without loss of efficiency at a temperature significantly lower than the temperature required to achieve similar activity using non-promoted alumina. For example, the yield of 1,1,1,2-tetrafluoroethane obtained from 1-chloro-2,2,2-trifluoroethane at relatively high temperatures of 360 ° C. or higher at atmospheric pressure when unpromoted alumina is used. While only 0.5%, zinc-promoted alumina would be sufficient to achieve higher reaction efficiencies even at lower temperatures above 280 ° C. On the other hand, if at the same temperature, say 300 ° C, the contact time will be shorter when using the promoted catalyst.

A preferred embodiment of the process of the invention is 1,1,1,2-tetra consisting of reacting hydrogen fluoride with 1-chloro-2,2,2-trifluoroethane in the vapor phase in the presence of an accelerated catalyst of the invention. Fluoroethane production method. This method will be carried out at atmospheric or overpressure at a temperature of about 280-500 ° C.

The process can be one step of a two or three step process, for example the first step is 1-chloro-2,2,2 by vapor phase fluorination of hydrogen fluoride with trichloroethylene in the presence of a fluorination catalyst. Trifluoroethane may be the second step of the process for preparing 1,1,1,2-tetrafluoroethane from trichloroethylene. The catalyzed catalyst of the present invention will be used in the first stage as well as the second stage of this two stage process. Typical reaction conditions for the first stage are temperatures ranging from about 180 to about 400 ° C and atmospheric or overpressure.

When 1,1,1,2-tetrafluoroethane is prepared from 1-chloro-2,2,2-trifluoroethane, the product contains 1-chloro-2,2-difluoroethylene, which is a harmful impurity. The stream is obtained. This impurity can be removed by reacting with hydrogen fluoride in the vapor phase in the presence of a fluorination catalyst at a temperature of about 270 ° C. or lower, for example 150-270 ° C. Since the promoted catalyst of the present invention can be used in the reaction, 1-chloro-2,2-difluoroethylene is essentially free from trichloroethylene using the promoted catalyst in one or more stages of each of the three reaction stages. Provided is a three step method of preparing 1,1,2-tetrafluoroethane.

Particularly preferred embodiments of the two-step process for preparing 1,1,1,2-tetrafluoroethane from trichloroethylene described above are (A) hydrogen chloride and 1,1,1, Mixture of fluorinated catalyst with 1-chloro-2,2,2-trifluoroethane and hydrogen fluoride at a temperature ranging from about 280 to about 450 ° C. in the first reaction zone to obtain a product containing 2-tetrafluoroethane. Contacting; (B) about 180 to obtain a product containing hydrogen fluoride and unreacted trichloroethylene, 1-chloro-2,2,2-trifluoroethane, 1,1,1,2-tetrafluoroethane and hydrogen chloride Passing the product of step (A) together with trichloroethylene to a second reaction zone containing a fluorination catalyst at a temperature in the range of about 400 ° C., but lower than the temperature in step (A); (C) separating hydrogen chloride and 1,1,1,2-tetrafluoroethane from 1-chloro-2,2,2-trifluoroethane, unreacted hydrogen fluoride and unreacted trichloroethylene Treating the product of c); And (D) supplying 1-chloro-2,2,2-trifluoroethane obtained from step (C) with hydrogen fluoride to the first reaction zone of step (A) above and mentioned in the foregoing. One chromium-free fluorination catalyst is used in at least one of steps (A) and (B).

In step (A) of this preferred embodiment at least a stoichiometric amount of hydrogen fluoride is usually used. Typical amounts of hydrogen fluoride per mole of 1-chloro-2,2,2-trifluoroethane are 1-10 moles, preferably 1-6 moles. Thus, the product of this reaction step will usually contain unreacted hydrogen fluoride in addition to 1,1,1,2-tetrafluoroethane, hydrogen chloride and by-products. The preferred reaction temperature in step (A) of the process is in the range of 325-385 ° C. under a contact time of 1-100 seconds, preferably 5-30 seconds, at 5-20 bar pressure.

10-100 moles, preferably 15-60 moles of hydrogen fluoride per mole of trichloroethylene are generally used in step (B). Again, the reaction product at this stage will usually contain unreacted hydrogen fluoride. Generally a contact time of 1-100 seconds, preferably 5-30 seconds, at 220-350 ° C. and 5-20 bar pressure will be used.

The method according to the invention, including preferred embodiments, is preferably operated continuously. In practice, however, continuous operation of the process will not be possible due to the catalyst inactivation, which involves periodic catalyst regeneration or reactivation. Supplying air to the catalyst during the practice of this method will prevent catalyst deactivation and reduce the frequency at which the process is stopped due to catalyst regeneration or reactivation.

The invention is further illustrated by the following non-limiting examples.

4.79 g of 0.5-1.4 mm granule-shaped alumina (from Harshaw Ltd) with a surface area of 180 m 2 / g was added to an aqueous solution of zinc chloride (0.21 g) in distilled water (10 ml) and then stirred to soak the solution in the solid. To listen. The mixture was directly heated to dryness, and the obtained solid was sieved to obtain a finished catalyst consisting of about 2.0% w / w zinc on alumina and having a particle size of 0.5-1.4 mm. Aside from increasing the concentration of the zinc chloride solution, the above procedure was repeated to produce a series of finished catalysts with up to 6.6% w / w zinc in the finished catalyst. The fluorination activity of zinc-promoted alumina was measured using an atmospheric pressure microreactor. The catalyst (2 g) was placed in a 1/4 "diameter microreactor, placed in an HF stream at 300 ° C. for 1 hour, heated to 350 ° C., and then placed in air / HF (ratio 1:20) for approximately 15 hours.

The microreactor was then fed a mixture of HF feed and 1-chloro-2,2,2-trifluoroethane 133a at a molar feed ratio of 1.0: 3.5 with a contact time of 2 seconds at 300 ° C.

Unpromoted alumina was also tested for comparison with promoted alumina.

The results are shown in Table 1 as% yield of 1,1,1,2-tetrafluoroethane, which means that the addition of zinc on alumina increases the yield of 1,1,1,2-tetrafluoroethane 134a. Demonstrate the beneficial effects of

The activity of the zinc impregnated alumina catalyst reached a peak in the range of about 2-about 3% w / w of zinc.

TABLE 1

Example 8

4.39 g of alumina (from Harshaw Ltd) in the form of granules of 0.5-1.4 mm in size and having a surface area of 180 m 2 / g was dissolved in distilled water (5 ml) with nickel (II) chloride hexahydrate (0.41 g) and zinc chloride (0.21 g) The solution was then soaked in to solid and soaked. The mixture was directly heated to dryness, and the solid obtained was sieved to obtain a finished catalyst of about 2.0% w / w zinc and about 2% w / w nickel on alumina and having a particle size of 0.5-1.4 mm.

2 g of this catalyst were tested at atmospheric pressure following the procedure of Examples 1-7.

The activity of the catalysts consisting of 2% by weight and 3.8% by weight of nickel on alumina, also prepared from aqueous solutions of nickel (II) chloride as described above for comparison, was also measured. The atomic loading of 3.8% nickel on the alumina catalyst is the same as that of the catalyst containing 2% zinc and 2% nickel.

The results are shown in the yield of 1,1,1,2-tetrafluoroethane in Table 2, which was obtained when the addition of nickel alone and the inferior effect of adding zinc / nickel compared to the addition of zinc alone. Despite the worse effects, however, the beneficial effect of zinc / nickel on alumina is demonstrated over alumina alone.

TABLE 2

Example 9

4.39 g of 0.5-1.4 mm granular alumina (Harshaw Ltd) with a surface area of 180 m 2 / g was added to an aqueous solution of cobalt (II) chloride hexahydrate (0.40 g) and zinc chloride (0.21 g) in distilled water (5 ml). Addition and stirring allowed the solution to soak in the solid. The mixture was directly heated to dryness, and the obtained solid was sieved to obtain a finished catalyst consisting of 2.0% w / w zinc and 2% w / w cobalt on alumina and having a particle size of 0.5-1.4 mm.

2 g of this catalyst were tested at atmospheric pressure following the procedure of Examples 1-7.

The activity of the catalysts, consisting of 2% by weight and 3.8% by weight of cobalt on alumina, also prepared from an aqueous solution of cobalt (II) chloride as described above for comparison purposes was also measured. The atomic loading of 3.8% cobalt on the alumina catalyst is the same as that of the catalyst containing 2% zinc and 2% cobalt.

The results are shown in Table 3 as% yield of 1,1,1,2-tetrafluoroethane, which was obtained when cobalt alone and inferior effects obtained when zinc / cobalt was added as compared to zinc alone. Despite the worse effect, however, the beneficial effect of zinc / cobalt on alumina is demonstrated compared to alumina alone.

TABLE 3

Example 10

4.43 g of 0.5-1.4 mm granular alumina (Harshaw Ltd) with a surface area of 180 m 2 / g was added to an aqueous solution of manganese (II) chloride tetrahydrate (0.36 g) and zinc chloride (0.21 g) in distilled water (5 ml). Addition and stirring allowed the solution to soak in the solid. The mixture was directly heated to dryness, and the obtained solid was sieved to obtain a finished catalyst consisting of 2.0% w / w zinc and 2% w / w manganese on alumina and having a particle size of 0.5-1.4 mm.

2 g of this catalyst were tested at atmospheric pressure following the procedure of Examples 1-7.

The activity of the catalysts consisting of 2% by weight and 3.6% by weight of manganese on an alumina prepared from an aqueous solution of manganese (II) chloride was also measured as described above for comparison purposes. The atomic loading of 3.68% manganese on the alumina catalyst is the same as that of the catalyst containing 2% zinc and 2% manganese.

The results are shown in the yield of 1,1,1,2-tetrafluoroethane in Table 4, which is obtained when the addition of manganese alone and the inferior effect of adding zinc / manganese compared to the addition of zinc alone. Despite the worse effect, however, the beneficial effect of zinc / manganese on alumina is demonstrated compared to alumina alone.

TABLE 4

Example 11-20

4.40 g of 0.5-1.4 mm granular alumina (Harshaw Ltd) with a surface area of 180 m 2 / g was added to an aqueous solution of iron (II) chloride (0.07 g) and zinc chloride (0.63 g) in distilled water (10 ml). It was then stirred to soak the solution in the solid. The mixture was directly heated to dryness, and the obtained solid was sieved to obtain a finished catalyst consisting of 6.0% w / w zinc and 0.5 w / w iron on alumina and having a particle size of 0.5-1.4 mm. Aside from varying concentrations of iron (II) chloride and zinc chloride solutions, the above procedure was repeated to obtain a series of finished catalysts with zinc and iron loadings given in Table 5.

2 g of this catalyst were tested at atmospheric pressure according to the procedure of Examples 1-7.

The activity of the catalyst consisting of 2% by weight of iron on alumina, also prepared from an aqueous solution of iron (II) chloride, as described above for comparison, was also measured. The atomic loadings of 6% w / w zinc and 0.5% w / w iron on alumina are the same as those of 6.6% w / w zinc on Example 7 (Aluminum 7) and the catalytic activity of Example 7 and Examples 3.5 and 6 Together for comparison purposes.

The results are shown in the yield percentage of 1,1,1,2-tetrafluoroethane in Table 5, and alumina with a relatively high zinc loading and a zinc and iron ratio of 2: 1 or more compared to iron alone or zinc alone. Demonstrates the beneficial effects of adding zinc / iron to

TABLE 5

Example 21-25

In the following examples, only iron among the metal species tested in combination with zinc was able to obtain more active catalyst than 6.6 wt% zinc on the alumina catalyst.

A catalyst was prepared according to the method described in Examples 1-12 above except that the solution to which alumina was added was as follows.

Example 21

Same as Example 12

Example 22

4.07 g of alumina was added to an aqueous solution of CoCl ₂ hexahydrate (0.3 g) and ZnCl ₂ (0.63 g) in 10 ml of water.

Example 23

4.07 g of alumina was added to an aqueous solution of NiCl ₂ hexahydrate (0.3 g) and ZnCl ₂ (0.63 g) in 10 ml of water.

Example 24

4.04 g of alumina was added to an aqueous solution of Mn (CH ₃ CO ₂ ) tetrahydrate (0.34 g) and ZnCl ₂ (0.63 g), either 10 ml of water.

Example 25

4.17 g of alumina was added to an aqueous solution of CuCl ₂ dihydrate (0.2 g) and ZnCl ₂ (0.63 g) in 10 ml of water.

2 g of each of these catalysts was tested at atmospheric pressure following the procedure of Examples 1-7.

The results are shown in Table 6 as% yield of 1,1,1,2-tetrafluoroethane and demonstrate the beneficial effect of adding zinc / iron to alumina compared to adding some other metal zinc to alumina. Let it be.

TABLE 6

Examples 26 and 27

4.98 g of aluminum fluoride in a granule form with a surface area of 13 m 2 / g and 0.5-1.4 mm, obtained by reacting hydrogen fluoride with alumina (manufactured by Harshaw Ltd) at 340 ° C. for 48 hours, was dissolved in distilled water (5 ml). (0.02 g) was added to the aqueous solution and stirred to allow the solution to soak into the solid. The mixture was directly heated to dryness, and the obtained solid was sieved to obtain a finished catalyst consisting of 0.2% w / w zinc on aluminum fluoride and having a particle size of 0.5-1.4 mm. The procedure was repeated except that the concentration of zinc (II) chloride solution was increased to give a finished catalyst of 0.5% w / w zinc on aluminum fluoride.

2 g of each of these catalysts was tested at atmospheric pressure following the procedure of Examples 1-7.

Unpromoted aluminum fluoride was also tested for the purpose of comparison with promoted aluminum fluoride catalyst.

The results are shown in% yield of 1,1,1,2-tetrafluoroethane.

TABLE 7

[Examples 28 and 29]

In these examples, the procedure described below was carried out using the catalysts prepared in Example 7 (Example 28) and Example 11 (Example 29).

0.67 g of catalyst was placed in a 1/4 "diameter Inconel reactor tube and dried at 300 ° C. and activated by heating in a hydrogen fluoride stream flowing at 20 ml / min for 1 hour. 1 second of contact time and trichloro Trichloroethylene and hydrogen fluoride were fed to the reactor under atmospheric pressure with an ethylene: hydrogen fluoride ratio of 1: 20.The activity of the catalyst was adjusted at a temperature in the range 210-250 ° C. and the result is “initial activity” in Table 8. Indicated.

The temperature was then raised to 350 ° C. for 3 hours. After 3 hours the temperature was lowered to 210-250 ° C. and catalytic activity was adjusted over this temperature range. This result is shown as "activity after 3 hours" in Table 8. The trichloroethylene and hydrogen fluoride feeds were then stopped and regenerated by heating the catalyst at 350 ° C. in an air stream flowing at a flow rate of 10 ml / min for 2 hours. After 2 hours, hydrogen fluoride and trichloroethylene were reflowed at 20 ml / min and 1 ml / min, respectively, and the catalytic activity was adjusted over a temperature range of 210-250 ° C. The results are shown in Table 8 as "activity after regeneration". All these results are shown in% yield of 1-chloro-2,2,2-trifluoroethane in Table 8, demonstrating the beneficial effect on the regeneration of zinc-promoted catalysts with the addition of iron.

TABLE 8

Claims (17)

One or more other than zinc selected from the group consisting of nickel, cobalt, manganese, iron and copper, supported on an alumina, halogenated alumina or aluminum oxyhalide support, containing as much metal and zinc as the activity promoting amount Chromium fluorination catalyst. The catalyst of claim 1 wherein the amount of zinc is about 0.5-30% by weight of the catalyst. The catalyst of claim 2 prepared by impregnating alumina, halogenated alumina or aluminum oxyhalide with a water soluble zinc salt and comprising about 0.5- about 10% by weight of zinc. The catalyst of claim 1, wherein the catalyst is prepared by co-precipitation of zinc hydroxide and aluminum hydroxide followed by conversion of the hydroxide to an oxide, wherein the amount of zinc is about 3- about 30 weight percent of the catalyst. The catalyst of claim 1 wherein the amount of metal other than zinc is at most 2.0% by weight of the catalyst. The catalyst of claim 1 wherein the metal is iron. The catalyst of claim 1 wherein the amount of zinc is at least 3% by weight of the catalyst. The catalyst of claim 6 wherein the weight percent ratio of zinc to iron is about 2: 1 to about 80: 1. The catalyst of claim 3 comprising at least 3% zinc by weight of the catalyst and further comprising about 0.1-about 2% iron by weight. 4. The catalyst of claim 3 further comprising iron and wherein the ratio of zinc to iron (% by weight based on catalyst weight) is 16: 1-2: 1. The catalyst of claim 4 further comprising iron and wherein the ratio of zinc to iron (% by weight based on catalyst weight) is about 16: 1-about2: 1. A process for producing a fluorinated hydrocarbon comprising reacting hydrogen fluoride and a hydrocarbon or halogenated hydrocarbon in the vapor phase in the presence of a fluorination catalyst as defined in claim 1. The method of claim 12, wherein the halogenated hydrocarbon comprises an alkane or alken having at least one chlorine atom and C _1-4 . The method of claim 13 wherein the halogenated hydrocarbon is in the group consisting of 1-chloro-2,2,2-trifluoroethane, trichloroethylene, 1-chloro-2,2-difluoroethylene and perchloroethylene The method chosen. 15. The process of claim 14 wherein (a) trichloroethylene is reacted with hydrogen fluoride to produce 1-chloro-2,2,2-trifluoroethane, and (b) 1-chloro- obtained in (a). Reacting 2,2,2-trifluoroethane with hydrogen fluoride to produce 1,1,1,2-tetrafluoroethane, wherein the catalyst as claimed in claim 1 is prepared by step (a) And (b) at least one of the steps. The process of claim 15 wherein (A) the 1-chloro-2,2,2-trifluoroethane and hydrogen fluoride mixture is contacted with a fluorination catalyst in a first reaction zone at a temperature in the range from about 280 to about 450 ° C. Preparing a product containing hydrogen chloride and 1,1,1,2-tetrafluoroethane with unreacted starting materials; (B) at a temperature in the range from about 200 to about 400 ° C., but lower than the temperature in step (A), the product of step (A) was treated with trichloroethylene in a second reaction zone containing a fluorination catalyst. Passing together to produce a product containing 1-chloro-2,2,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, hydrogen chloride and unreacted trichloroethylene and hydrogen fluoride; (C) treating the product of step (B) to obtain hydrogen chloride and 1,1,1,2-tetra from 1-chloro-2,2,2-trifluoroethane, unreacted hydrogen fluoride and unreacted trichloroethylene Separating the fluoroethane; And (D) feeding 1-chloro-2,2,2-trifluoroethane obtained from step (C) with hydrogen fluoride to the first reaction zone (step (A)) above, wherein Wherein the fluorination catalyst used in at least one of steps (A) and (B) is a chromium free fluorination catalyst as claimed in claim 1. The method of claim 12, wherein the catalyst is periodically regenerated by contact with air at a temperature of about 300 ° C. to about 500 ° C. 18.