DE955587C - Process for the production of metal oxide catalysts - Google Patents

Description

ISSUED JANUARY 3, 1957

St 5369 IVa 112 g

The invention relates to a process for the production of catalysts which are made from metal oxide gels, z. B. aluminum oxide gel, zinc oxide gel, chromium oxide gel exist.

According to the invention, a phenol or cresol or substituted phenol or cresol in an im essential anhydrous form with a metal such as aluminum, magnesium, zinc, titanium, calcium, Chromium, manganese or alloys of these metals, brought into reaction to form a metal phenolate or cresylate. Mixtures of phenol and cresols can also be used. Used advantageously a small amount of a catalyst to promote the reaction.

The metal phenate or cresylate, e.g. B. aluminum or zinc phenate or cresylate, is hydrolyzed. The resulting water-containing metal oxide is dried and calcined.

The products manufactured according to the claimed process are characterized by a large surface and of such a high degree of purity that it is not necessary to remove harmful ions.

Since the phenols or cresols are only sparingly water-soluble, they are hydrolyzed by the phenolate or

Cresylates are excreted, whereupon they can be recovered and reused in the process. That regenerated phenol or the cresols contain some dissolved water. You will get from this for example freed by heating to give essentially anhydrous phenol or cresol. In the Hydrolysis gives an aqueous sludge of the hydrous metal oxide.

To make an alumina or zinc oxide gel, the slurry of the hydrous Metal oxide dried and activated in the usual way. You can also use the slurry of the Before drying, treat metal oxide with solutions of catalytic substances, e.g. B. Solutions from Ammonium molybdate, chromic acid, etc.

Instead of hydrolyzing the metal phenate or cresylate with water, you can do it with a Hydrolyze silicic acid hydrosol, a silicic acid hydrogel or an impregnation solution, which have a contains catalytically active substance, so that mixed catalysts are formed when the resulting Mixture is dried and activated. If you use silicic acid hydrosol, some water, which is consumed in the hydrolysis, extracted from the as silicic acid hydrosol, whereby the formation is accelerated by silica hydrogel.

For the production of aluminum oxide gel, metallic aluminum is used e.g. B. in the form of chips, Grist, turnings or ingots in reaction with an essentially anhydrous phenol or a cresol brought. Small amounts of catalytically active substances can be added, such as mercury salts, Iodine or aluminum halide, preferably mercury chloride. This catalyst can work together with added to the metal or separately. When using mercury chloride one takes about 0.01 to 1, preferably about 0.1 part by weight of mercury chloride per part by weight of aluminum. The reaction can be carried out at atmospheric or elevated pressure will.

It is necessary to adjust the reaction mixture to about 177 to 204 degrees, advantageously about 180 degrees when using phenol and. to 190 ⁰ when using cresol mixtures to initiate the reaction between aluminum and phenol. During the reaction, the mixture is maintained at a temperature of about 177-204 ^0th Aluminum and phenol or cresol together form aluminum phenolate or cresylate and hydrogen, which is essentially pure and can be used as such. The overhead vapors from the reaction mixture can be cooled and the condensed liquid and hydrogen recovered.

The reaction products, which are a solution of aluminum phenolate or aluminum cresylate in phenol or Represent cresol can be hydrolyzed in the reaction zone itself or in a suitable hydrolyzing zone as which a mixing nozzle, centrifugal pump or similar arrangement can be used. The hydrolysis stage is water, Steam or an aqueous colloidal solution such as a silica or other hydrosol, silica hydrogel or an aqueous impregnation solution supplied to the phenolate or cresylate solution with formation of hydrolyze hydrous aluminum oxide and the formation of phenol or cresol. While During hydrolysis, the temperature is between about 1.7 and 204 °. During hydrolysis with silicic acid hydrosol or hydrogel, aluminum phenolate or cresylate is hydrolyzed and water from the silicic acid hydrosol or hydrogel removed, resulting in a mixture of silica and aluminum oxide, which can be dried and used as a cracking catalyst for hydrocarbons.

When carrying out the reaction between metal and phenolate, the mixture can be heated to the boiling point of the phenol, which is allowed to flow back into the reaction vessel by reflux cooling. When the reaction is complete, in one embodiment of the invention 'steam is passed through the mixture at a temperature of about 100-204 ⁰ to hydrolyze the aluminum alkoxide and aluminum hydroxide to leave the reaction vessel, while water and phenol flow off via the top. In this embodiment of the invention, the phenol is essentially completely separated from the aluminum hydroxide. Phenol or cresol is separated from the water in the vapors leaving the reaction vessel, for example by condensation, cooling, settling and separation of the aqueous layer. This can then be _{saturated with CO 2} -containing gas in order to still win the relatively little phenol or cresol dissolved in it.

As an example of making a zinc aluminate or spinel catalyst that is useful for flavoring or hydroforming reactions, an alloy of 54 weight percent zinc was used and 46 weight percent Aluminduia partly with Phenol, partly reacted with cresol.

example 1

400 g of zinc-aluminum alloy in the form of chips were reacted with 2500 g of phenol in a reflux condenser, using ig HgCl ₈ as a catalyst or pathogen. The reactants were held at atmospheric pressure at the temperature of the boiling phenol until virtually all of the metal had dissolved, with the phenol being reused. The reaction mixture was then hydrolyzed with 101% of hot water. The precipitate was filtered off and washed with distilled water. The washed-out product, which contains zinc and aluminum hydroxide, was heated for 3 hours with 190 g of glacial acetic acid which had been diluted with 1 cm of water. To this solution, 200 cc of an ammoniacal solution of an NH ₃ content of about 4 ° / ₀ added, were dissolved in 51.5 g of ammonium molybdate, and the iao resulting mixture was thoroughly worked through. The product was dried at 120 ^0, then calcined at 650 ⁰ hours and placed in a spherical shape. The resulting catalyst contained 40 percent by weight ZnO, 49 percent by weight Al ₂ O ₃ and 135 percent by weight Mo O ₃ . In this approach were

2δο ecm catalyst in dried and calcined Form won.

Example 2

2500 ecm cresol were reacted with 400 g of an alloy of 46 ⁰ I ₀ aluminum and 54% zinc in a reflux condenser, using HgCl ₂ as the pathogen. The reaction mixture was kept at the temperature of the boiling cresol at atmospheric pressure until the alloy had dissolved with refluxing cresol. The mixture contained in the reaction vessel was hydrolyzed with 301 distilled water. The resulting mixture was steam distilled to recover the cresol. The dry precipitate, which contains zinc and aluminum hydroxide, was worked through with an ammoniacal solution of ammonium molybdate, which had been prepared according to Example 1. The mixture was then dried at 120 °, calcined at 650 ° for 3 hours and finally shaped into spheres. The composition of the catalyst corresponded to that of the product according to Example 1. In Example 2, about 180 ecm of dried and calcined catalyst were obtained.

The catalysts prepared according to Examples 1 and 2 were used with a fixed catalyst bed in a hydroforming, the starting material of which was a 66 ° to 12 ° fraction of untreated East Texas oil; the average catalyst temperature was 510 °, the feed rate (liquid) 1.2 parts by volume / parts by volume / hour, the molar ratio of H ₂ to hydrocarbon 2: 1 and the reaction time 4 hours. The reaction vessel had a capacity of 500 ecm and was under a pressure of 3.4 atm. operated. The following results were achieved:

Amount of catalyst, ecm

Produced gasoline

Octane number, CFR-Res.

Yield, percent by volume

Gas, weight percent

Carbon,
Weight percent ..

Catalyst,

made of

Phenolate | Cresylate

280.0

89.0

86.0 8.0

2.3

180.0

86.0

88.0 7.6

2.0

Normal catalyst

500.0.

83.0 '

94.0 4.8

0.7

The normal catalyst was prepared by stirring zinc sulfate and sodium aluminate solutions together to precipitate zinc and aluminum hydroxide, followed by filtering and washing to remove the sodium and 5μ ^ ίίοηβη. The moist filter cake was worked through with an ammoniacal solution of ammonium molybdate, dried at 120 °, calcined for 3 hours at 650 ° and then shaped into pills. The catalyst contained 90 percent by weight ZnO · Al ₂ O ₃ and 10 percent by weight MoO ₃ .

From the values given above it can be seen that when using products prepared according to the invention Catalytic converters are given a gasoline with a higher octane rating. ■

Example 3

81 g of aluminum turnings were refluxed with 1000 g of anhydrous phenol using 0.1 g of HgCl ₂ as a catalyst. The reactants were held at the temperature of the boiling phenol with the refluxing phenol. The product was then hydrolyzed by pouring 101 water into it and stirring. The A1 (OH) ₃ precipitate was filtered off and washed free of phenol with distilled water. The washed-out precipitate was homogenized with washed-out silica hydrogel, dried and then calcined at 538 ° for 3 hours. The resulting product had the following composition (percent by weight, dry): 87% SiO ₂ + 13 ° / ₀ Al ₂ O ₃ . The yield was 94% of the starting materials used.

Example 4

A catalyst according to Example 3 was prepared by hydrolyzing aluminum cresylate, which by treating aluminum turnings with boiling cresol using HgCl ^ as Catalyst and hydrolyzing with steam was made to precipitate aluminum hydroxide, which in the form of coarse pieces was removed from the flask and washed out. The washed out precipitate was homogenized with washed out silica hydrogel, dried and as in Example 3 at Calcined at 538 °.

Example 5

A catalyst was prepared which corresponds to the product prepared according to Example 3, by mixing aluminum hydroxide, which was obtained from the 100 phenolate, with a pure silica sol mixed, which of sodium ions by percolation through the bed of a cation exchange resin was cleaned. The slurry of aluminum hydroxide and silica sol became Evaporated to dryness and then calcined at 538 ° for 3 hours.

Example 6

A catalyst corresponding to that prepared according to Example 4 was obtained by mixing aluminum hydroxide obtained from the cresylate with a pure silica sol, the sodium ions of which had been removed by percolation through the bed of a cation exchange resin. The slurry of aluminum hydroxide and silica sol was evaporated to dryness and then calcined for 3 hours at 538 ^0th

Suitable cleavage catalysts can also be produced by a hydrolysis of Aluminum phenolate or cresylate produced aluminum hydroxide with mixed sodium silicate acid solutions or mixed with silica sols which have been produced in any way. One can also hydrolyze an anhydrous aluminum phenolate or cresylate with the help of a silicic acid hydrosol

sieren, which is prepared in the usual way or by treatment with a cation exchange resin so that water was removed from the silica sol during hydrolysis and silica hydrogel is formed. You can also use the aluminum phenolate or cresylate in the presence of silicon alcoholate, such as an alkyl silicate, or with a silicon halide, e.g. B. silicon tetrachloride, hydrolyze.

ίο If you have catalytic converters, which in the above Wise prepared, used to crack a heavy gas oil at 510 °, one obtains a gasoline yield of about 36 percent by volume, this gasoline having a research octane number (neat) of about 96.4 Has.

Crude or impure phenolic compounds can be treated in dilute or concentrated mixtures or solutions of hydrocarbons with aluminum or the other metals and the phenolates formed can be separated from the impurities and hydrolyzed, whereby essentially pure phenolic compounds are recovered. In order to obtain pure phenol or cresol from crude or impure mixtures, the impure mixture is treated with aluminum at a temperature at or above the boiling point of phenol or cresol, HgCl ₂ being advantageously used as the pathogen. Other metals, such as zinc, can also be used in place of aluminum. The phenolate or the cresylates are separated from the remaining hydrocarbon mixture, e.g. B. by cooling to below about + 4.4 ° and then filtering. The crystals of aluminum phenolate or cresylate are treated with a suitable solvent, e.g. B. light paraffins such as n-heptane, n-pentane or mixtures thereof or with light hydrocarbon distillate oils washed out. The leached metal compounds or crystals are then hydrolyzed with steam or water in order to regenerate the phenol or the cresols and to precipitate an active adsorptive form of aluminum oxide, such as the hydroxide, which is further treated in a known manner, e.g. By drying or calcining to form aluminum oxide. It is also possible to separate phenol from the cresols and to separate the individual cresols themselves by dissolving the aluminum phenolate and the cresylates in a suitable hot solvent such as toluene and dam? the individual aluminum cresylates and then the phenolate precipitate in a fractionated manner by gradually cooling the toluene solution in order to precipitate the various aluminum salts, filtering off after each cooling stage and then cooling further to precipitate the next lower melting compound. The separated cresylates and the phenolate are then hydrolyzed separately in order to obtain phenol and the individual cresols. This process can be used in particular when the impurities have approximately the same boiling range as the phenol or the cresols, so that simple distillation cannot be used.

The aluminum oxide obtained as a by-product is used as an adsorbent and / or as a catalyst or catalyst support of value. During the reaction of metal and phenates, it becomes hydrogen developed.

In 'another embodiment of the invention higher reaction rates are achieved by using heated, evaporated, low-boiling water-soluble alcohols or phenols are used with heated metals, or one wins the heat through the heat of formation of the alcoholate or phenolate. If the respondents have a have a low boiling point, the reaction rate is extremely slow. This is especially true when methyl alcohol reacts with aluminum or other metals or alloys as well as in general if other metals such as zinc, chromium, manganese, zinc-aluminum alloys, Aluminum-chromium alloys and aluminum-manganese alloys, with the lower boiling aliphatic alcohols are implemented. According to this embodiment, methyl alcohol evaporated, the vapors are heated to about 163 to 204 °. The metal or metal alloy will also heated to approximately the same temperature to initiate the reaction. The heat of reaction holds that Metal to reaction temperature without additional heat supply. In this embodiment, you can cheap alcohols, such as methyl alcohol, can be used without applying pressure to remove the To increase the temperature of the reaction mixture. You can also bring other metals into reaction.

Essentially anhydrous methyl alcohol is evaporated to produce aluminum methylate. The vapors are passed through an insulated heated column containing a load of aluminum scrap treated _{with a suitable catalyst such as HgCl 2.} The temperature of the metal is adjusted so that it is below the decomposition temperature of the aluminum methylate formed, which flows down to the base of the column. The heat of reaction supplies the majority of that amount of heat which is required to heat the methyl alcohol vapors to the reaction temperature. The hydrogen generated in the course of the reaction and the alcohol vapors flowing up the column are cooled to condense and recover the alcohol and then return it to the base of the reaction column. The aluminum methylate can be used as such or hydrolyzed with water. To win aluminum hydroxide, which is dried and calcined, whereby a strongly adsorptive aluminum oxide is obtained, which as such or z. B. can be used as a catalyst in combination with molybdenum oxide or silica.

Claims (8)

PATENT APPLICATIONS: i. Process for the production of metal oxide catalysts, characterized in that a metal with an anhydrous phenol or cresol or its substitution products or with vapors of a low-boiling water-soluble one Treated alcohol at a higher temperature, the The metal alkoxide formed is hydrolyzed and the resulting hydrous metal oxide is dried and is calcined. 2. The method according to claim i, characterized in that that aluminum or an alloy of aluminum and zinc is used as the metal. 3. The method according to claim i, characterized in that treating the metal with phenol or cresol at its boiling point. 4. The method according to claim 1, characterized in that that the vapors of the low-boiling alcohol to a temperature above the boiling point of the same to be heated. 5. The method according to claim 1, characterized in that that the metal alkoxide is hydrolyzed with silicic acid hydrosol. 6. The method according to claim 1, characterized in that that the metal alkoxide is hydrolyzed with an aqueous solution, which is a catalytic one active substance, e.g. B. molybdenum. " 7. The method according to claim 1, characterized in that that the hydrous MetaJloxyd with a metal or silicon compound, z. B. Ammonium molybdate, silica hydrogel or hydrosol, added. 8. The method according to claims 1 to 6, characterized in that one consists of a zinc-aluminum alloy washes out hydrous metal alkoxide obtained with anhydrous phenol or cresol and after mixing with acetic acid with an ammoniacal solution of ammonium molybdate mixed up. Considered publications:
German patent specification No. 820 893. © 609549/470 T. (609 726 12. 56)