DE929186C - Process for the production of low-boiling hydrocarbons from higher-boiling hydrocarbons by catalytic cracking - Google Patents

Description

Process for the production of low-boiling hydrocarbons higher-boiling hydrocarbons through catalytic cleavage in patent 886 897 is a process for the production of low-boiling hydrocarbons from higher-boiling ones Hydrocarbons by catalytic cleavage in the presence of hydrogen elevated pressure, in particular from a to ioo at, and temperatures from 35o to 55o ' described, using a catalyst active in the preparation thereof Alumina or aluminum hydroxide with an iron group metal or a compound provided thereof and before or afterwards with fluorine or a volatile fluorine compound was treated. In addition, one or more metals can be added to the catalyst 5th, 6th or platinum group of the periodic table or their compounds added will. According to the procedure of the additional patent 898443 is in the production of the Alumina catalyst proceed in such a way that an aluminum salt or aluminate solution and a salt solution of an iron group metal together or separately from each other precipitates with a precipitant, whereupon the precipitate as such or with separate precipitation after prior mixing, expediently after heating, with Fluorine or volatile fluorine compounds is treated and heated. The catalyst one can then still with a metal of the iron group or its compounds, z. B. the oxide or fluoride provided.

According to the additional patent 915 330 , these catalysts are to be used for the refining hydrogenation of hydrocarbons at temperatures from Zoo to 475 ° and under normal or elevated pressure. In the case of the catalysts described, from 0.5 to 400/0, advantageously from 2 to 20%, of the metal of the iron group, based on the alumina, are generally used.

It has now been found that these catalysts are effective in the reactions mentioned are particularly effective, especially the duration of their usability up to Resuscitation is prolonged when the content of the catalyst on the compound of the metal of the iron group is at least 500/0, expediently more.

The finished catalyst therefore contains about 10 to 50 percent by weight, expediently 3o to 5o percent by weight, advantageously 40 to 50 percent by weight, active Alumina or aluminum hydroxide. As has also been shown, in this Case in addition to the aluminum compound, other earth metal compounds, such as. B. Use thorium or cerium, especially their oxides. -The earth metal compounds and those of the iron group can be precipitated separately or, more conveniently, together. In this case, it is advantageous to use elevated temperatures, e.g. B. 50 to 100 °. It is it is also expedient to carry out the precipitation at a pH above 7. As a precipitant ammonia and amines are well suited. In the case of separate precipitation, the mixture is intimately mixed the precipitation, advantageously when it is still damp. It is convenient that Peptize precipitates with a small amount of an acid, making a pulp or a paste is created. It can also be the moist precipitate of the compound Iron group with the earth metal compound, e.g. B. clay, or vice versa, mixed will.

As described in the main patent, the catalyst can also be small Amounts of active silica, activated fuller's earth or synthetically produced silicates, z. B. of aluminum, zinc, iron, nickel or cobalt.

The mixed metal compounds are then heated to a higher temperature, z. B. 30o to 50o °, heated and then with fluorine, hydrogen fluoride, ammonium fluoride or hydrofluoric acid treated at ordinary or elevated temperature. The catalyst can be deformed before or after.

The solid catalyst should be about 1 to 20%, advantageously 1 to 15% 0/0, contain fluorine.

The fluorine can also be partially replaced by other halogens, e.g. B. chlorine, or their ammonium compounds, as well as hydrogen halide or mineral acids, such as hydrochloric acid, sulfuric acid or nitric acid. Will be expedient the catalyst washed out and heated after this treatment.

As stated in the main patent, the catalyst is suitable excellent for splitting hydrocarbons in the presence of hydrogen under a pressure of: 2 to 100 atm and recirculation of the hydrogen-containing gases, z. B. in an amount of 0.5 to 6 cbm per kilogram of raw material. Here draws the long-term effectiveness of the catalyst until regeneration the end. Even at higher pressures, namely up to about iooo at, e.g. B. in the divisive Pressure hydrogenation, the catalyst has great advantages in that it has no or only very small amounts of metals of the 5th and 6th group are required to produce fission products, such as B. gasoline, in good yield and quality. The higher the pressure the lower the amount of valuable hydrogenating agents required by the catalyst Compounds of metals of the 5th and 6th group of the periodic table.

The starting material can be present in the presence of the treatment described or absence of hydrogen initially via adsorbent, sulfur-binding Metals or hydrogenating catalysts and silicates of the iron group passed before it comes into contact with the described catalyst. One can also a high-boiling starting material, e.g. B. crude oil or crude oil residue, with this Crack the catalyst in a finely divided state and then, for. B. with the same Catalyst, pressure hydrogenate in the bottom phase.

As has been found, the catalyst is also for dehydrogenation and reforming suitable. Example i 5560 g of commercial aluminum sulfate (A12 [p 0413. 18 H2 O) with 2o% aqueous ammonia at 9o to 95 ° and with a pH 8.2 to 8.5 precipitated, washed free of sulfate with hot water and still moist Homogenized with freshly precipitated iron hydroxide in a Retsch mill for one hour. the Paste is spread on metal sheets, dried at 100 ° and heated at 400 ° for 6 hours. After cooling, the oxide mixture is granulated (4 to 6 mm) with 10% hydrofluoric acid soaked, dried and heated at 400 ° for 8 hours. The finished catalyst contains around 66 0/0. Fee 03, 28% A12 03 and 6% F. To produce the iron hydroxide is a solution of 7400 g of commercial ferrous sulfate (Fe S 04 - 7 H2 O) with concentrated Nitric acid oxidized at 6o to 70 °, precipitated with 2o to 25% ammonia water, the precipitate was left to stand hot for 2 hours, filtered and washed.

1 liter of this catalyst is installed in a high pressure furnace and heated to 40o ° without prior reduction. During the hour you pass 0.5 liters of a paraffinic petroleum middle oil with a specific gravity of 0.833, an aniline point of 70.5 °, an initial boiling point of 2o5 ° 'and from which 85% to 35o ° boil, together with 500 liters of hydrogen ( measured cold) at a total pressure of 50 at over the catalyst. The reaction product, which is obtained in a yield of 97 percent by volume, contains 480/0 gasoline with a final boiling point of 200 ° and an octane number according to the engine method of 73. The residual medium oil has an aniline point of 66 °. If the activity of the catalyst decreases after a while, the temperature is gradually increased by about 10 °. Reaction times up to regeneration of 200 hours are achieved at a maximum temperature of 480 °. The catalyst regains its initial activity through subsequent regeneration with oxygen-containing gas.

Example e 556o e commercial aluminum sulfate (A12 [S 0413 i 8 H2 O) and 20409 iron-3-chloride are dissolved in water and at 9o to 95 ° with 2o% aqueous ammonia precipitated at a pH of 8.2 to 8.5, sulfate-free with hot water washed, dried and heated for 6 hours at 400 ". The iron oxide-aluminum oxide mixture has a weight ratio of i: i and is impregnated with 10% hydrofluoric acid and dried and heated to 4oo °. The finished catalyst contains 47%, Fee 03, 43% Ale 03 and i o% HF.

The same amount of the oil mentioned in Example i is passed over this catalyst at 400 ° and 100 at total pressure together with the same amount of hydrogen. After 8 days of uninterrupted operation, the catalyst still shows no loss of activity. The reaction product, which is obtained in an amount of 98 percent by volume with a specific gravity of 0.765 , contains 57% gasoline (final boiling point 200 °, octane number 72 according to the engine method); the residual oil has an aniline point of 68 ".

Will the same oil at 41o ° and a throughput of 1.5 kg per hour together with 25oo 1 hydrogen per kilogram of oil and hour at 25o at total pressure Passed over 1 l of this catalyst, it is obtained with a yield of 100 Percent by volume a reaction product with a specific gravity of 0.757, which is 62% gasoline contains.

Claims (2)

PATENT CLAIMS: i. Process for the production of low-boiling hydrocarbons from higher boiling hydrocarbons by catalytic cleavage according to patent 886 897, characterized in that the catalyst used has a content of the Compound of the metal of the iron group of at least So%, expediently more. 2. The method according to claim i, characterized in that the finished catalyst Contains i to 20%, advantageously i to 15%, fluorine.