DE1054624B - Process for the dehydrocyclization and dehydrogenation of starting materials consisting entirely or partially of non-aromatic hydrocarbons - Google Patents

Description

The invention relates to the dehydrocyclization and dehydrogenation of petroleum hydrocarbons for the production of aromatics or petrol.

It is known to use petroleum fractions, e.g. B. in the gasoline boiling range, through catalytic reforming treatments to increase their octane number. Various catalysts have been proposed for this purpose, whereby often metal compounds of VI. or VIII. Group of the Periodic Table on one completely or partially made of aluminum oxide can be used. So was the conversion from aliphatic to aromatic. Hydrocarbons using catalysts described, which consists of a small amount of chromium oxide on a carrier of a larger amount of aluminum oxide exist. It has also been suggested, paraffinic and olefinic hydrocarbons in convert aromatic compounds by bringing them into contact with catalysts that are cyclizing active compound, such as chromium oxide, contained on an aluminum oxide carrier and with 2.5 to 20% a rare earth and 6 to 30% potassium, rubidium or cesium, each based on the weight of the cyclizing metal compound, are activated.

It has already been proposed to use boron-containing catalysts for the dehydrogenation of naphthenes, i. H. from saturated ring-shaped compounds with simultaneous conversion into the corresponding aromatic to use unsaturated ring-shaped compounds. The invention relates to this to dehydrocyclization, d. H. on the formation of new ring systems from open hydrocarbon chains in the starting material.

The invention is a further improvement of reforming processes with Chromium oxide-aluminum oxide catalysts. be performed.

According to the invention, a starting material consisting entirely or in part of non-aromatic hydrocarbons is used at temperatures between 450 and 580 ° C. and pressures up to 4.55 kg / cm ² without hydrogen fed back into the reaction zone or added externally over catalysts made of chromium oxide, aluminum oxide and a small +5 amount of boron and converted into a product whose aromatic content is higher than that of the starting material.

In the process according to the invention, in addition to the product which is liquid under normal conditions and has a significant content of aromatics and some olfins, a considerable amount of hydrogen-rich gas is obtained as a valuable by-product. The expression "at pressures up to 4.55 kg / cm ² " encompasses processes for the dehydrocyclization and dehydrogenation of starting materials consisting entirely or in part of non-aromatic hydrocarbons

Applicant:

The British Petroleum Company Limited, London

Representative:

Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald, Dr.-Ing. Th. Meyer and Dipl.-Chem. Dr. phil. H. Siebeneicher, Patent attorneys, Cologne 1, Deichmannhaus

Claimed priority; Great Britain 7 December 1956

John Arthur Edgar Moy and Bernard Whiting Burbidge, Sunbury-on-Thames, Middlesex (Great Britain), have been named as inventors

Normal pressure and pressures below. Normal pressure is preferred. Preferably one works at Temperatures in the vicinity of 525 ° C. and with room flow rates of the liquid starting material of in particular 0.1 to 1.0 V / V / hour.

The boron is preferably present in the catalyst as an oxide. The catalyst preferably contains also a small amount of an alkali metal compound, e.g. potassium, especially as an oxide.

The constituents of the catalyst are preferably present in the following proportions on the entire catalyst stable at 550 ° C:

Chromium oxide 5 to 25%

Boron (as oxide) 0.1 to 5%

Alkali metal (as oxide) 0.1 to 5%

Alumina remainder

809 789/458

The catalysts can be used in the form of fixed bed, fluidized bed or fluidized bed catalysts will. Since the catalytic converters burn off the carbonaceous deposits in a Allowing streams of oxygen-containing gas to be easily regenerated are particularly suitable for the process Fluidized bed or fluidized bed catalysts.

As previously indicated, the process drops large amounts of hydrogen-rich gas as valuable By-product.

The raw material used should be in the light petrol or petrol sector (light or heavy petrol) boil. In particular, fractions that 'predominantly consist of a mixture of hydrocarbons with 5 to 7 carbon atoms are preferred.

According to one embodiment of the invention, a straight-run gasoline, in particular a low boiling fraction of a, commonly referred to as the primary rapid distillate Direct distillation used. The treatment according to the invention can produce gasoline blending components with a high octane number from such starting materials and high volatility, especially with research octane numbers (without addition) of at least 90 and a volatility of at least 70% at 100 ° C.

According to another embodiment, the product of a preceding can be used as the starting material catalytic reforming processes can be used. The inventive method comprises thus a 2-stage reforming process, according to which aromatics and gasoline fractions with a high research octane number, preferably of about 100 (without addition) can be obtained. In the first stage any suitable reforming method can be used. A process. In which platinum catalysts be used on an aluminum oxide carrier with or without bound halogen, however, it is preferred. Such processes are called the platinum reforming process and the products referred to as platinum reformates.

In such a 2-stage process, the entire reformate can be transferred from the first stage to the second Stage to be reformed. But since its higher-boiling end fraction is rich in aromatics, it doesn't go any further can be converted, the reformate is preferably fractionated and a lower-boiling, relatively aromatic-free fraction obtained, which is then fed to further treatment.

Optionally, the reformate can also be subjected to solvent extraction and the raffinate or some of the raffinate can be treated further. If necessary, the product can also be used with the higher-boiling Fraction or with the extract from the solvent extraction or else with others Components with high octane ratings, e.g. B. high-boiling, catalytically cracked gasoline or Alkylates are mixed.

The catalysts can be used in any suitable manner, e.g. B. by impregnating the aluminum oxide with a solution containing chromium, boron and preferably potassium. The invention will explained in the examples below.

example 1

A platform is separated into low-boiling and high-boiling fractions, with the low-boiling Frakao tion has a final boiling point of 108 ° C and a research octane number (without addition) of 76.1. This light fraction of the Platformats will be further reformed under the following conditions:

Pressure normal pressure

Room flow rate .... 0.2 V / V / hour.

Recirculated gas volume ■ -

Duration of the procedure 5 hours

Reaction temperature 530 ° C.

There are four runs under the above conditions with the following different catalysts carried out:

1. 10% chromium oxide on aluminum oxide.

2. 10% chromium oxide on aluminum oxide with 1% ceria and 1% potassium oxide.

3. 10% chromium oxide on aluminum oxide with 1% boron oxide.

4. 10% chromium oxide on aluminum oxide with 1% boron oxide and 1% potassium oxide.

All percentages relate to a material stable at 550 ° C. The comparison values for the four attempts are listed in the table below.

Tabel

Butane-free liquid product Exit gas Catalyst composition yield Research octane number Flow velocity age H ₂ content Weight percent (without addition) m ³ / m ³ Volume percentage 1. 10% Cr ₂ 0 ₃ / Al ₂ 0 ₃ , not activated 67 100.0 335.7 77 2. 10% Cr ₂ 0 ₃ / Al ₂ O ₃ +1% Ce +1% K 62 102.2 322.2 81 3. 10% Cr ₂ O ₃ / Al ₂ O ₃ + 1% B 64 101.2 297.2 77 4th 10% Cr ₂ 0 ₃ / Al ₂ O ₃ + 1% B + 1% K 68 103.3 342.7 73

A straight run, low boiling point gasoline with an ASTM boiling range of 41 to 87 ° C and a research octane number of 63.3 (without addition) is treated under the following conditions:

Pressure normal pressure

Room flow velocity .... 0.2 V / V / hour.

Recirculated gas volume -

Duration of treatment 5 hours

Claims (5)

5 6 Tests are carried out at different temperatures. The results are listed in the doors with the catalysts of experiments 2 and 14 of the table below. Table butane-free productExhaust gasCatalystTemperatureYieldResearch-flow-H2-content0CWeight octane number velocity percent (without addition) m3 / m3Volume percent47586,182,015282,752468,494,632477,04758780,8137865306394,636081,5 Patent claims: 1. A process for the dehydrocyclization and dehydrogenation of starting materials consisting entirely or partially of non-aromatic hydrocarbons using boron-containing catalysts, characterized in that the starting materials are at temperatures in the range from 450 to 580 ° C, pressures up to 4.55 kg / cm ² and be passed over catalysts containing chromium oxide, aluminum oxide and small amounts of boron without hydrogen returned to the reaction zone or added from outside. 2. The method according to claim 1, characterized in that in addition small amounts of alkali metals, preferably potassium-containing catalysts are used. 3. Process according to Claims 1 and 2, characterized in that 5 to 25% chromium oxide, 0.1 containing up to 5% boron (as oxide) and preferably 0.1 to 5% of an alkali metal (as oxide) Catalysts are used. 4. The method according to claims 1 to 3, characterized in that space flow velocities of the liquid starting material from 0.1 to 1 V / V / hr. be used. 5. The method according to claims 1 to 4, characterized in that a starting material Mixture of hydrocarbons with predominantly 5 to 7 carbon atoms, such as a Straight-run distillate or part of a catalytic reformate, in particular a platform, be used. Considered publications:
German patent specifications No. 814 293, 855 705. © 809 789/458 3.59