DE2255176A1 - CATALYTIC PREPARATIONS - Google Patents

Description

DR. BERG DIPL-ING. STAPF

8 MUNICH 8O, MAUERK1RCHER5TR. 45

Dr. Berg Dipl.-Ing. Stapf, 8 Munich 80, Mauerkircherstraße 45 Your sign, your writing Our sign date

10. Ncv, ffll

Attorney file 22 985
Be / Ro

Monsanto Company
St. Louis / üSA

"Catalytic Preparations"

The present invention "relates to the manufacture of Copper salt catalysts that are used in the oxidation of hydrogen chloride and in the oxidative chlorination of hydrocarbons are valuable. In particular, it relates to improved copper (II) halide catalysts and their use in an oxidative chlorination process.

The chlorination of hydrocarbon gases with hydrogen chloride and air or oxygen is a well-known one

0-08-19-0546 309 8 20/097

Procedure. Conventionally, suitable catalysts are used to accelerate the reaction. Usually The catalysts used contain salts, especially the halides of metals with different valences. These Salts have been used as such, together with various promoting substances and together with mineral substances or deposited thereon, such as asbestos, diatomaceous earth, pumice stone, clay, gravel, alumina, silicon dioxide and like used. A particularly effective catalyst contains a copper halide in combination with an activated one Alumina or deposited on it, or a catalyst preparation which uses the copper halide as an effective catalytic Contains agent impregnated on activated aluminum oxide. The procedure so far has been general in that way carried out that a mixture of hydrogen chloride, oxygen or air and the hydrocarbon by a Reaction chamber conducts which contains a stationary or plague bed of the catalyst. Recently, however, the catalyst is becoming in finely divided form according to the fluidized bed process referred to above used. One of the main disadvantages of copper halide catalysts is that they work with the required reaction temperatures are volatile, ils therefore the catalyst composition can no longer maintain its effectiveness Time is retained because of the loss of copper halide and it must be continuously replaced or recovered and the Reaction zone are fed back. The problem of catalyst losses is increased when the catalyst is in

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V / fluid bed is used, because because of the larger surface, which one through'die subdivision of the catalyst particles the loss of copper shark ο genid no.oh is more pronounced and the catalyst service life is even shorter.

Another disadvantage of the catalysts used hitherto is the sensitivity of the catalysts to them Iron pollution. The catalysts are usually used in a ferrous device and in normal operation, iron-containing corrosion products that introduced through the feed gas line or formed in the reaction vessel itself by the catalysts trapped, resulting in a loss of activity with a subsequent decrease in yields and a significant increase the abrasion speed leads. Occasionally, periods of abnormal work or disturbance conditions aggravate this problem.

The usual method of copper halide on an effective To apply carrier, is that you the carrier in In the form of granules, pellets or finely divided particles impregnated with an aqueous solution of the copper halide and then drying the mixture at the desired temperature. A much improved catalyst can be formed when the carrier is impregnated with a solution of the copper halide in an alcohol and then dried, as described in U.S. Patent 3,010,913.

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With this catalyst, the corrosion problems in the reaction vessel compared to those with catalysts, manufactured by the more common methods. However, this catalyst still suffers the disadvantages described above, especially if there are disruptions in working conditions.

A significant advance in this area is achieved by a superior catalyst that has high activity, lasting stability due to its excellent resistance to iron contamination and has significantly lower abrasion losses, and which is described in US Pat. No. 3,461,084. The procedure The preparation of this catalyst is also much easier because it can be carried out without a solvent. However, during the time will if Oxygen or air is absent in the reaction system and the catalyst exclusively by hydrocarbon and / or HCl streams is swirled, this catalyst is so disadvantageous

he
Lig affects that when reused in the oxidative chlorination reaction, its stability and abrasion resistance in the presence of iron impurities are seriously impaired. Because such periods of lack of oxygen, for example when starting and stopping the system, as well as in the event of unexpected malfunctions, where the air or oxygen supply is switched off for a certain time and tries to avoid complete shutdown,

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occur, it is particularly desirable that the catalyst not suffer from any degradation during such an operation. It has now been found that the tendency to decompose under the specified difficult conditions can be avoided if the aluminum oxide which is used for the catalyst prepared by the l'rookenmiseh method of US Pat. No. 3-461,084 is or is of a certain type has specific properties.

According to the invention, improved catalytic preparations containing a copper (II) halide as the active catalytic constituent together with an activated aluminum oxide or supported thereon can be obtained by adding, in the dry state, a water-falling copper (II) halide with an activated one 'alumina mixed and heated, wherein the alumina has the following properties: (1) a loss on ignition at 1UOO ⁰ O from 3 up to 8 "/>, (2) a sodium content of less than 0,055a" measured as sodium oxide, (3) a Crystal structure derived from a mixture of boehmite and gamma alumina, the mixture being shown by an X-ray diffraction pattern with lines at 138 to 140 & \ 2.33 to 2.38 %, 1.96 to 2.00 £, 6 , 1 to 6.2 i, 1.83 to 1.88 i, and 3.1 to 3.2 &, and the strongest line is 1.38 to 1.40 % , and (4) an average crystal size of LiO - $ 100 based on the line width at 3.1 to

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3.2 ft and from 30 to 40 Å based on the strip width at 1.96 to 2.00 &. With such an activated alumina as a catalyst support, the above-mentioned process disadvantages are avoided in an oxidative Ohlorierungsverfahren, ils may further include the minimum temperature to which the catalyst is heated, to be reduced from the conventionally used 35O ⁰ O ⁰ C to 3UO. I) the catalyst made with this alumina shows remarkable improvements in resistance to attrition in the presence of iron, even when exposed to hydrocarbon and / or HGl contact without oxygen in the system during fluidization is. Furthermore, the loss in converting capacity of HGl that occurs when iron is present in the normal oxidative chlorination process is reduced when using the improved catalyst of the present invention.

To prepare the catalyst of the invention, anhydrous Copper (II) halide in finely divided i'orm and activated alumina dry at any temperature from room temperature to the temperature of the heat treatment stage mixed by any device and then subjected to the heat treatment. This method is suitable himself, the iv.;. to produce ulyser in the reaction vessel, in to which it is to be reserved or, if desired, in a simple extinguishing device to produce.

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As described above, the minimum temperature at which the catalyst mixture is heat-treated, 3OO ⁰ C, although temperatures can be used up to about 600 ⁰ O. The duration of the treatment of the catalyst changes depending on the temperature at which the treatment is carried out. Less time is required at higher temperatures than at lower temperatures. The minimum treatment time at minimum temperatures is at least 2 hours. In general, in order to obtain satisfactory results, the heat treatment is carried out at a temperature of 300-350 ° for 2 to 16 hours. Particularly preferred treatment conditions are heating at 300 ⁰ G _{0 for 6 hours}

The hydroxyl content of the alumina is an important factor in the preparation of the catalyst. Without looking up. any theoretical discussions regarding the exact mechanism of formation of the improved catalyst of the invention through the improved dry mash process set, it is believed that the superiority of the catalyst from the deposition of monomeric copper (II) halide molecules on the alumina surface in the form of -0-OuX bonds, where X is halogen. It is known, that the surface of aluminum oxide with different amounts of hydroxyl groups, depending on the manufacturing and Burning conditions is covered. These hydroxyl groups are linked to the surface aluminum atoms. The reaction such hydroxyl groups with the monomeric form of a copper

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Fer-II-halide forms the species -0-GuX with elimination of hydrogen halide, which can associate with the clone and catalyze the reaction. The hydroxyl content is measured by determining the percentage burn loss (LOI) at 1000 ° C. The minimum LOI to ensure a sufficient number of hydroxyl groups on the alumina surface to react with the cupric halide to form the effective catalytic species is about $ 3. A LOI value above 8p indicates the presence of free absorbed water on the surface of the aluminum oxide, which causes hydration of the copper (II) halide and consequently the contact between the copper (II) halide and the hydroxyl groups on the surface of the aluminum oxide with impairment can delay or inhibit the formation of the active catalytic species. The alumina used in the dry mixing stage should therefore have an LOI between about y-β> and about 8 ^J / o , but preferably the alumina used for the catalyst support should have an LOI of about 5 to about I / o .

Alumina with a LOI lower than the specified minimum can be hydrated according to known methods, for which it is simply exposed to the humid atmosphere, subjected to steam treatment, etc. while alumina is included can be easily dehydrated with a LOI above the maximum value. Dehydration is easy by heating

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of the aluminum oxide at temperatures of about 200 to about 6OQ ⁰ G for 2 to about 6 hours. In general, the heating supplies of alumina containing freely absorbed water, at temperatures of 350 to 45O ⁰ O during a period of about 4 hours, a satisfactory support material,

The invention is illustrated in the following example, without thereby limiting the scope of the invention target. All parts are parts by weight, unless otherwise stated. The X-ray diffraction patterns were obtained with alumina samples which were ground to a particle size of 0.074 mm mesh size, whereby one a Phillips-Norelco X-ray diffractometer with a Copper radiation source (OuKcc) and a focusing monochromator used, which scans at 1 deg / kinute. the Conversion of 2 θ angles into d-spacings is done using the usual tables,

The crystallite size is an estimate that can be obtained from the Width of the indicated diffraction peak using the following Scherrer equation is obtained

K λ

D =

Oos θ
2

where D is the crystallite size and
'K = the shape factor = 0.9
λ ■ = GuKct wavelength = 1.542 Å

bV2 = the width of the tip at half the height

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θ = the 3-spectrometer angle at which the peak occurs,

modified for the instrument as follows K λ

D =

0.1) Cos θ using 0.1 as

Correction factor

example

Different batches of copper-chloride-on-alumina catalysts were made as Catalysts A, B and C using different samples of activated alumina. The catalyst A prepared by vmrde oxide with Aluini ni containing 0.4 "/ ° sodium as sodium oxide, as vmrde determined by emission spectroscopy, and the one having the boehmite ici substantially similar crystalline structure (alpha alumina monohydrate, or aluminum oxide hydroxide), wherein some Jhi aluminum oxide was mixed in, the mixture exhibiting the following X-ray diffraction pattern »

"d" distance (i) intensity (l / l _Q ) (tip area)

1.38 - 1.40 100 6.1 - 6.2 77 3.1 - 3.2 52 1.83 - 1.88 45 2.33 - 2.38 37 1.96 - 2.00 16

The average crystallite size, determined by means of X-ray diffraction, was about 273 i based on a diffraction rate at 3.1 to 3.2 % and 192 S based on one

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Fringes at 1.96 to 2.00 L Approximately 1200 parts of alumina were first for two hours at 250 - dried to ensure 2.80 ⁰ O that the LOI at 1000 ° 0 in the range of 3 to Q ° ß>. Drying was effected by bubbling heated nitrogen gas through the alumina which is in a fluidized bed reaction vessel while maintaining a fluidized state. Thereafter, the alumina was heated to 300 ⁰ C and 300 parts of finely divided anhydrous copper chloride and 200 parts of alumina were mixed thoroughly mit'dem treated alumina at this temperature by continuing fluidization with heated nitrogen in the reaction vessel. The mixture was then heated in a similar manner at a controlled temperature of 35O ⁰ C for about 8 hours. The final catalyst contained approximately 6.7 ^ copper as determined by X-ray fluorescence analysis.

The alumina used to make Catalyst B. contained $ 1.0 sodium as sodium oxide and had one Crystal structure that is essentially that of gamma aluminum oxide and shows the following X-ray diffraction pattern:

"d" distance (i) ■ intensity (1 / I ₀ )

1.38 - 1.40 100

1.96-3.00'77.8

The average crystallite size was determined by means of X-ray, diffraction analysis determined to be approximately 35 ft. Approximately

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225517Θ

1000 parts of this aluminum oxide were ^{dried for seventeen hours at 250 °} C. in a fluidized bed reaction vessel, the fluidization being effected by heated nitrogen. The alumina was then transferred to a mixing vessel and 360 parts of finely divided anhydrous copper chloride were thoroughly mixed with this alumina in the vessel. The mixture was then introduced into a fluidized bed Reaktionegefäß, brought to a temperature of 35O ⁰ C and heated for 6 hours at this temperature under fluidization conditions. The final catalyst contained approximately 11.7 # copper.

A third sample of activated alumina supporting no detectable Men _t e sodium contained, the catalyst C was used for the preparation. The crystallite structure of this aluminum oxide corresponded to that of a mixture of boehmite and gamma aluminum oxide, the mixture exhibiting the following X-ray diffraction pattern »

"d) Distance (ft) Intensity (l / l _Q )

1.38 - 1.40 100 2.33 - 2.38 91.9 1.96 - 2.00 85.5 6.1 - 6.2 78.5 1.83 - 1.88 57.5 3.1 - 3.2 56.6

The average crystallite size, determined from the tip at 3.1 bia 3.2 α in the diffraction image, was about 61 ft, while at 1.96 to 2.00 ft it was about 35 ft,

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After drying for two hours at 25Q ⁰ G 660 parts of this alumina were mixed with 160 parts of finely divided anhydrous copper chloride and v / Eiteren 150 parts of alumina in a fluidized bed reaction vessel mixed, heated nitrogen was passed through the bed to the formation of fluidization. The mixture was then 8 hours at a temperature of 30ü - heating 35O ⁰ G under constant vortexing. The final catalyst had a copper content of 7 »6 & ew» / o.

A number of experiments were carried out in which ethylene was converted into 1,2-dichloroethane by oxidative chlorination using catalysts A, B and G. Each catalyst was first tested as it was freshly prepared to determine the basic activity in the oxidative chlorination reaction and with regard to catalyst attrition. Thereafter, after adding 3.0 $ iron as leJ ^ -z and after treatment with ethylene and HCl without oxygen, the catalyst was examined again in the oxidative chlorination process. For this purpose, about 1000 ecm of each catalyst were introduced into each of 3 identical fluidized bed reaction vessels with jackets of about 1.5 m length and 54 mol diameter, which were then electrically heated via a wire wrapping made of nichrome tape on the outside of the jacket. was added to the catalyst bed via an outer bed of fluidized alumina, which circulates within the reaction vessel jacket.

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rolls, fed. A pyrex glass filter that is electric with about 6 m Uichromba, nd was heated, was used for collection the catalyst dust or the fines are used. The exhaust gas from the reaction vessel was covered with catalyst dust separated by means of a glass frit sintered to medium porosity within the filter.

The reaction vessels were operated in parallel. After loading of the catalyst was at 180 - 200 ⁰ C heated while being held with air under fluidized bed conditions. The filter was weighed to an approximate value of 0.1 g. HCl and ethylene were then introduced and the flow rate of HCl, CgH. and air were regulated so that the catalyst was kept under fluidized conditions and a molar ratio HGIiCgH ^ iOg of 1, Qi1: 0.58 was maintained. The reaction temperature was maintained between 235 and 245 ^° C. during the reaction time, the pressure being approximately atmospheric. The contact time between the reactants and the catalyst in the fluidized bed system was approximately 5 »0 seconds.

After stable conditions, ie high activity and low particle abrasion of the catalyst, the reaction was stopped. The catalyst was sieved and 3 $ iron as iron oxide (Fe ₂ O- *) was added to it. The catalyst was then returned to the vessel, brought to the desired temperature and only charged with C ₂ H. and HCl and treated in this way for 2 to 4 hours. After this treatment

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lungszeit became the normal working process of the oxidative Chlorination procedure as described above, again applied.

Dichloroethane and unreacted HCl were released from the gaseous Waste stream recovered by cooling and passing through a series of water washers. The product conversion was calculated according to the HCl feed and the HCl remaining in the exhaust gas was determined by titrating the aqueous phase from the water by means of an alkaline standard solution certainly. The abrasion was determined by the difference in the filter weights and as a percentage / day as is calculated as follows:

(Weight) (weight

(Catalyst + filter) "of the filter)

$ / Day ⁼ —— χ 24 hours /

(Weight of the catalyst (hours from day χ TCO gate charge) of the last

Measurement)

The test results are shown in Table I below. The data obtained here clearly show that the catalyst C made with alumina and containing no sodium, and from a particular mixture of Boehmite and gamma-alumina are the ones used, as determined by an X-ray diffraction pattern is far superior to other catalysts, both in terms of its resistance to degradation and in terms of its activity for converting HCl in the oxidative chlorination reaction, since it is the least is affected by iron contamination.

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Table I.

Ver Cataly- Ha in iron Real- Hand- Through- Cataly-

such sator aluminum traction- sectional sator-

No oxide give time time wall abrasion

A. t Gewo? S Weight ° / o (hours) (Hours.) ment % /,/Day 1 A. 0.4 0 47 99.7 1.2 2 B. 0.4 3 55 2.0 84.8 40 3 B. 1.0 0 379 - 99.5 0.18 4th 0 1.0 '3 14th 3.0 90.3 32 5 C. HD ^X 0 45 - 98.1 0.37 6th G ND 3 119 2.0 98.0 0.75 7th C. ND 0 55 - 99.3 0.07 8th ND 3 435 2.0 99.3 0.83 footnote

χ not determined

Although the invention has been described with respect to a specific copper chloride catalyst, it is not limited thereto. The method of catalyst preparation is also applicable in cases where the active ingredient of the catalyst is a cupric halide other than cupric chloride, for example cupric bromide or cupric fluoride, although these catalysts are generally somewhat less effective. The catalysts can also contain various amounts of copper halide. In general, the amount of catalyst used is so great that about 3 to about 12% by weight of copper are present in the catalyst preparation. the alkali metal and alkaline earth metals and 3 0 9 8 2 0/0978 ~ ¹⁷ ~

_ ₁₇ _ 22.5517Θ

the like deposited on alumina are produced by the process and show the same improvements over the catalysts when used according to the state of the art.

In the same way, the conditions under which the oxidative chlorination reaction using copper (II) halide, which have been prepared by the process of the invention, proceeds, can be changed considerably without deviating from the concept of the invention, or can live in addition to ethylene a number of other unsaturated organic compounds are chlorinated, for example propylene, 1-butene, 2-butene, 1-pentene, 2-pentene, 3-methyl-1-butene, 1-methyl-2-butene, 2-methyl-3 -butene, 1-hexene, 2-hexene, 4-methyl-1,3-pentene, 3-dimethyl-1-butene, 4-methyl-1,3-pentene, 3-dimethyl-1-butene, 4-methyl-2-pentene , .1-0ctene, O / clopentene, cyclohexene, 3-methyl-cyclohexene ,. 1,3-butadiene, 1,3-pentadiene, 1o4-pentadiene, 1 «4-hexadiene, 1,3-hexadiene, acetylene, propyne, 1-butyne, 2-pentyne, 1-hexene, etc., so / ie their homologues and analogs . Halogenated, unsaturated organic compounds which have one or more halogen atoms and one or more olefinic and / or acetylenic bonds can also be chlorinated using the catalysts of the invention = Examples include: vinyl halide, allyl halides, 2-halopropylene, Crotylhalogenide, 2-halo-butene 1-, methallyl, 2-halo-2-butene, monohalogenated acetylenes, 1 ■ 1-Oihalogenäthyleh;. -halo-1-pentene, 3-halo-cyclopentene and 3-Halogeh- 309,820 / 0978 * " ¹⁸ "

cyclohexene, 3-halo-i.4-pentadiene and the like, their Homologues and analogs.

Saturated hydrocarbons such as methane, ethane, propane, η-butane, isobutane and the like can also be used the oxidative chlorination process with the here produced catalysts are chlorinated. These hydrocarbons generally have higher temperatures than required for the corresponding unsaturated materials. The hydrocarbons and others mentioned here Compounds can be treated individually or as mixtures with one another. When mixtures of saturated and unsaturated Hydrocarbons are used, it is possible to selectively halogenate one or the other by suitable control of the reaction conditions. The hydrogen chloride, Oxygen, oxygen-containing gases or air, and the organic compound intended for chlorination, can at the bottom of the reaction vessel containing the catalyst contains in a finely divided state, "are introduced" Gases of the reactants are then used to swirl the Catalyst. The three reactants can but auoh be introduced into the reaction vessel in separate streams or it can be air or oxygen in admixture with the Hydrocarbon and the hydrogen chloride are introduced. For reasons of the risk of explosion one should use different Hydrocarbons no mixture of hydrocarbons and oxygen the reaction temperature without chlorine

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let hydrogen reach. The use of a fluidized bed is preferred over the fixed bed ", although this the latter can be used if desired. The minimum gas velocity required to create turbulence is is low. Linear gas velocities on the order of 0.030-0.30 m / second are generally satisfactory and avoid excessive blowdown of the catalyst fines. A certain depth or density of the catalyst in the reactor bed is required and should be sufficient to provide satisfactory fluidization conditions of the catalyst is reached and there should be sufficient contact time available for the substantial transformation of the desired product when used To reach temperature. A surface contact time of 0.5 to 10 seconds or more is below sufficient for normal working conditions.

The relative proportions of hydrocarbon or halogenated organic compound, hydrogen chloride and oxygen, Air or oxygen-containing gas can easily be calculated will. To convert ethylene into dichloroethane, for example, the ratio of the reactants according to the can be determined using the following equation:

2HC1 + C ₂ H ₄ + 1 / 2O ₂

The theoretical amount of oxygen required is therefore 0.5 moles per 2 moles of hydrogen chloride. There can be stoichi

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metric amounts of the reactants are used in the respective reaction, but the equilibrium be shifted in the oxidation reaction using excesses of one or the other of the reactants can. For example, if you get a saturated chlorinated compound from a non-saturated hydrocarbon Desires to produce, for example, a very small excess of oxygen may be preferred, the stoichiometric Amounts of hydrocarbon to hydrogen chloride to oxygen are 1: 2: 0.50. When air instead of oxygen is used, the preferred ratio of hydrocarbon hydrogen chloride: air is 1: 1.8: 2.75. It can, however other ratios may be used depending on the particular catalyst used and the product desired will.

In general, temperatures may be used in the products according to the invention catalysts in the range of about 180 to about 45O ⁰ C. The particularly preferred temperature in this broad possible range may vary to some extent with the nature of the catalyst and the hydrocarbon reactant used. In the oxidative chlorination of ethylene with the copper chloride on aluminum catalyst made in accordance with the invention, conversions of HCl as high as $ 100 can be achieved at as low as 220 ° C in the reaction zone. When other SaI-

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ze are used with copper chloride, the operating temperature range is usually higher, but also provides here the improved catalyst of the invention increased conversions at lower temperatures and with significantly lower abrasion speeds.

The invention is not limited to the implementation of the Ohlorwasseratoffoxidationsreaktion in the presence of an organic Chlorakzeptors, but they can also be used for the oxidation of hydrogen chloride, if no acceptor is present, d _o h. it can be used in the Deacon reaction referred to above.

Claims : -22-

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Claims (2)

Patent claims: hy catalytic preparations contain copper (II) halide as an effective catalyst component together with activated aluminum oxide, produced by mixing anhydrous copper (II) halide with an activated aluminum oxide in the dry state and heating, characterized in that the activated aluminum oxide (1) has a burning loss of 1000 ⁰ C from 3 to 8 ° / o, (2) a sodium content of less than 0.05 wt. ^, (3) a crystalline structure derived from a mixture of boehmite and gamma-alumina, the mixture having an X-ray diffraction pattern Stripes at 1.38 to 1.40 , 2.33 to 2.38, 1.96 to 2.00, 6.1 to 6.2 Ϊ, 1.83 to 1.88, and 3.1 up to 3.2 X, and the strongest stripe occurs in the range between 1.38 to 1.40 pounds, and (4) an average crystallite size of 50 to 100 Å based on the width of the diffraction stripes at 3.1 to 3, 2 & and from 30 to 40 & based on the width of the diffraction strips from 1.96 to 2.00 1 has » 2. Catalyst preparation according to claim 1, characterized in that the copper (II) halide is copper (II) chloride, and that the preparation is produced by heating at 300 ⁰ O for about two to sixteen hours. 309820/0978