DE1071254B - Process for the dehydrogenation and dehydrocyclization of non-aromatic hydrocarbons - Google Patents

Description

GERMAN

The invention relates to dehydration or dehydrocyclization of non-aromatic hydrocarbons.

In the process according to the invention for the dehydrogenation or dehydrocyclization of whole or Starting materials consisting partly of non-aromatic hydrocarbons becomes the starting material treated at elevated temperatures with catalysts containing chromium oxide on a support. preferably contain aluminum oxide, as well as small amounts of a spinel.

“Spinel” is understood to mean a group of compounds with a face-centered cubic crystal structure of the general formula MM ' ₂ O ₄ , in which M and M' are metals. For example, M 'can be a monovalent metal and M a hexavalent metal (ie M' ₂ O · MO ₃ ) or M 'a divalent metal and M a tetravalent metal (ie 2M'Ö-MO) or M' a trivalent metal and M a divalent metal (i.e. MZ ₂ O ₃ MO).

Chromites, such as cobalt chromite with CoCr ₂ O ₄ , copper chromite CuCr ₉ O ₄ and liisichromite FeCr ₂ O ₄ , and titanates, for example zinc titanate Zri ₂ TiO _4, are particularly effective spinels. All spinels can be artificially produced and used in this form. Iron chromite also occurs naturally in the »chrome iron stone«. This ore canoe contains 50 per cent or more ice uchromite, and the ore can be used even without separating the pure iron chromite.

l) i> Catalysts can optionally also be small Other activating agents, e.g. B. alkali metals, preferably contain potassium.

The process according to the invention is preferably carried out at pressures of up to 4.55 kg / cm ² and without hydrogen returned to the reaction zone or added from outside. The process produces substantial amounts of hydrogen gas as a complete by-product. The expression "pressures up to 4.55 kg / cm ² " includes normal pressure and pressures below; normal pressure is preferred. Temperatures of 45 ° C. are preferred > is 580 ° C and at room airflow velocity from 0.1 to 1.OV / V / hour.

It has been found that, within the specified conditions, chromium oxide-aluminum oxide catalysts activated with spinel are particularly effective in the case of severe reaction conditions and give products with a research octane number (without addition) of 100 or more. At such high octane numbers, the reduction in the yield when the octane number is increased is less pronounced when using spin-activated chromium oxide-aluminum oxide catalysts instead of known processes for dehydrogenation, for example with cerium or potassium
and dehydrocyclization of non-aromatic hydrocarbons

Applicant:

The British Petroleum Company Limited, London

Representative: Dr.-Ing. A. v. Kreisler, patent attorney,
Cologne 1, Deichmannhaus

Claimed priority:
Great Britain February 19 and May 31, 1957

John Arthur Edgar Moy,

Peter Thomas White and Bernard Whiting Burbidge, Sunbury-on-Thames, Middlesex (Great Britain),

have been named as inventors

fourth chromium oxide-aluminum oxide catalysts is being worked on. Because of this, the yield is higher for a given octane number.

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.

Pure hydrocarbons, z. B. straight-chain paraffins or cycloparaffins or mixtures of hydrocarbons boiling in the light gasoline or gasoline range are used. In particular, non-aromatic hydrocarbons with 5 to 7 carbon atoms or predominantly mixtures consisting of non-aromatic hydrocarbons containing 5 to 7 carbon atoms used.

According to one embodiment of the invention, a straight-run gasoline, in particular a low-boiling straight-run fraction known as light gasoline is used. Through the Correct treatment can result from such Starting materials ien gasoline mixture components with high octane number and high volatility, in particular with Rcsearch octane numbers (without addition) of wcnig-

909 689/522

at least 90 and a volatility of at least 70% can be produced at 100 ° C.

According to another embodiment, the product of a preceding one can be used as the starting material more catalytic! Reforming processes can be used. The method according to the invention thus comprises a 2-stage reforming process, after the aromatic and benzene / infractions with a high octane number, preferably of about 100 (Research without addition), can be obtained. Any suitable reforming process can be used in the first stage be applied. One process is called platinum catalysts be used on an alumina support with or without a hound halogen, however, it is preferred. Such processes are called platforming processes and the products are called Platformatc called.

With such a 2-step process, the entire Reformat from the first stage to be reformed in the second stage. But since its higher boiling point If the fraction is rich in aromatics which cannot be further converted, the reformate is preferred fractionated and thereby a lower-boiling, relatively aromatic-free fraction obtained, the then subjected to further treatment. Optionally, the reformate can also be used in solvent extraction and the raffinate or a portion of the raffinate are wciterbchandclt. Possibly the product can also be mixed with the higher-boiling fraction or with the extract from the solvent extraction or with other components with high octane numbers, e.g. B. high-boiling, catalytically packed gasolines or alkylates.

Components of the catalysts used in the process according to the invention for their production In the context of this invention no protection is claimed based on the total at 550 ° C stable catalyst, are preferably present in the following proportions:

Chromium oxide 5 to 25%

Spinel 0.1 to 10%, especially 2 to 5% (but less than the chromium oxide)

Other activating agents

(as oxide) 0.1 to 5%

Alumiuiumoxid remainder

The catalysts can be in any suitable manner, for example impregnation or coprecipitation, getting produced.

example 1

A copper chromite - chromox) d - alumina catalyst is made as follows:

Copper chromite is made by roasting an intimate mixture of copper nitrate and chromium oxide for 2 hours produced at 700 ° C. The product is extracted with hot, dilute nitric acid, washed and dried.

4 g of copper chromite are suspended in a solution of 1326 g of aluminum nitrate in 1/1 of distilled water. 650 ecm of an analytically pure ammonia solution (specific weight 0.88) are added with vigorous stirring. The mass is filtered, washed with 6 l of warm distilled water and then with 1 l of a 4% acetic acid solution. The filter cake is dried overnight at 50 ° C., then for 3 hours at 120 ° C. and calcined at 550 ° C. for 2 hours. The calcined material is crushed into particles with a diameter of 4.76 mm and with 28 g of analytical grade. impregnated chromium trioxide dissolved in 80 ecm of distilled water. The catalyst is dried at 120 ⁰ C and calcined for 2 hours at 550 ° C.

Example 2

One by reforming a straight-run gasoline fraction over a halogen-containing platinum catalyst Reformate produced on an alumina support is separated into light and heavy fractions. The light fraction has a final boiling point of 108 ° C and a Rcsearch octane number (without addition) from 76.1. This lower fraction of the platform is further treated under the following conditions :

Pressure atmospheric pressure

Room flow velocity 0.2 V / V / hour.

Recirculated gas volume -
Expiry time 5 hours

The results are shown in the table below.

Tabel

catalyst / composition

Reaction temperature

⁰ C

Butane-free liquid product
Research Octane Number

yield

Weight percent without additive

Exit gas
Flowing

speed
mVm ³

Ho salary
Volume percentage

1. 10% Cr ₂ CyAl ₂ O ₃

2. 10% Cr ₂ O ₃ Ml ₀ O ₃

+ 1% CoCr ₂ Ct ₄

3. 10% Cr ₂ O ₃ Ml ₂ O., /
4-2% CoCr ₂ O _4. ' 1

4. Al ₂ O ₃ + 1% CoCr ₂ O ₄

5. Al ₂ O ₃ + 10% CoCr ₂ O ₄

475
530

475
530

475
530

475
530

475
530

94.2
100.1

94.7
102.5

95.5
104.4

74.4
82.7

82.1
94.0

158
333

203
392

204
399

10.7
109

93
467

80

77

75
67

68
63

<30
48

8 +
85

Au ;, the table shows that with the hot Trials Nos. 2 and 3 used catalysts containing both chromium oxide and cobalt chromite on an aluminum oxide carrier products with noticeably higher octane numbers than in experiment No. 1.4 and 5 are obtained, in which the catalysts on alumina supports only one of the chromium compounds, d. H. either chromium oxide or cobalt chromite, but not both components.

Example 3

A low boiling point straight-RuII gasoline with a final boiling point of 112 ⁰ C and a research Octauzahl (without additive) of 61.2 is treated under the following process conditions with an activated catalyst with 2% Kobaltchromit from 10% chromic oxide to alumina:

Pressure atinosphere pressure

Room flow velocity 0.2 V / V / hour.

Recirculated gas volume -

Duration of the procedure 5 hours

Catalyst chromium oxide and cobalt chromite on aluminum oxide support

The results are shown in Table 2 below.

Table 2

Reaction temperature

⁰ C

ßutanfrcic "!
liquid product

yield
Weight percent

Research

Octane number

without addition

Exhaust gas

Was called-

speed

m '/ m'

H2 content

Volume percentage

475 76 81.5 214 71 530 50 ^l 98.8 487 73

Example 4

A low boiling Fiaktion a through reforming of a straight-run Bcnzinfraktion over a halogen-containing platinum catalyst on a support of alumina reformate produced with a boiling range of Cj hydrocarbons to 110 ⁰ C and a research octane number (without the addition) of 72.9 is under the The following process conditions were treated with a catalyst made of 10% chromium oxide on an aluminum oxide support and activated with 2% copper chromite:

] huck atmospheric pressure

Room flow

speed 0.2 V / V / hour

Recirculated gas volume ■ -

Duration of the procedure 5 hours

Catalyst chromium oxide and copper chromite on aluminum oxide carrier

The results are shown in Table 3.

Table 3

Reaction temperature

Butane frcics
liquid product
Yield 'research weight j octane ahl
percent I without addition

475 79 91.4 189 75 530 48 102.3 396 61

Exit gas I ^; hot-

speed

Hj salary

Volume percentage

Example 5

The procedure of Example 4 is followed using the same starting material and the same Process conditions carried out, but a catalyst activated with 2% zinc titanate from 10% Chromium oxide used on an aluminum oxide carrier.

The results are shown in Table 4.

Table 4

»5 Feedback 30th 475 Butane free Rescarch Exit gas ty / ^ "U 1" temperature 530 liquid product Octane number Flowing ri2-Cjenak yield without addition cspeed Volume ⁰ C Weight speed percent percent 91.2 m '/ rn' 101.9 85 81 166 79 58 382

B e i s ρ i e 1 6

Naturally occurring *. Chromei.senerz with a Iron chromite spinel content of 50% is ground to a particle size of less than 40 μm in diameter. 10 g of it are in a solution of 1326 g of aluminum nitrate in IV21 distilled water suspended. With vigorous stirring, 650 ecm of analytically pure ammonia solution (specific weight 0.88) was added. The mass is filtered and washed with 6 l of warm distilled water. The filter cake is left to dry overnight at 50 ° C and then 3 hours at 120 ° C and 2 hours calcined at 550 ° C. The calcined material is mixed with 28 g of analytically pure water in 80 ecm of distilled water impregnated with dissolved chromium trioxide. The catalyst is dried at 120 ° C and 2 hours at Calcined 550 ° C.

Example 7

A low-boiling platform with the same boiling range and octane number of Example 4 is used treated under the following conditions:

Reaction temperature .... 530 ° C

Pressure atmospheric pressure

Room flow velocity 0.2 V / V / hour.

Recirculated gases .... -

Duration of treatment 5 hours

Comparative tests are carried out using different catalysts. The used Catalysts and the results obtained with them are listed in Table 5 below.

Tabel

catalyst

Butane-free liquid product
Yield rescarch

Weight octane number

percent without addition

Flow rate

m '/ m ¹

Exit gas

H2 content percentage by volume

10%> Cliromoxide on aluminum oxide, activated with 1% cerium and 1% potassium

10% chromium oxide on aluminum oxide, activated with 5% chrome iron stone (produced according to example 6)

67.0

50.4

100.6

103.9

329

381

83.2

74.8

Example 8

Further experiments are carried out using the low-boiling platinum reformate of Example 7 same pressing. Space flow rates and process time and in the absence of recycled Gas carried out. However, a wider temperature range is used. It will investigated two catalysts, a chromium oxide-aluminum-oxide catalyst activated with synthetic iron chromite, which was produced according to the method of Example 1 and one with 5% chrome iron stone and 1% potassium oxide activated catalyst

ao chromium oxide — aluminum oxide.

The temperatures used and the results are shown in Table 6 below.

Tabel

catalyst

temperature

⁰ C Butanfreics liquid product
Yield I Rcscardi weight octane / steel
pro / ent without addition

Exit gas flow rate

m ^s / m ^J

H ₂ content percent by volume

10% Cr ₂ CyAl ₂ O ₃ + 5 _{% synthetic FeCr 2} O ₄ j 10% Cr, O ₃ / Al ₂ O ₃ + 5% chrome iron stone

475 530

475 530 550 81.3
59.4

81.6
67.3
62.4

90.4
101.6

93.1
100.7
102.0

154 306

183 375 387

79.5 79

89.3 82.9 78.8

Claims (9)

Patent claims: 1. Process for the dehydrogenation or dehydrocyclization of wholly or partly non-aromatic Starting materials consisting of hydrocarbons, characterized in that the starting material at elevated temperatures with chromium oxide on a carrier material and contacting a small amount of a catalyst containing spinel. 2. The method according to claim 1, characterized in that the carrier material is aluminum oxide is used. 3. Process according to Claims 1 and 2, characterized in that catalysts with a content from 5 to 25% Cliromoxyd and 0.1 to 10% of a spinel can be used. 4. Process according to Claims 1 to 3, characterized in that in addition small amounts Catalysts containing an alkali metal, in particular potassium, can be used. 5. Process according to Claims 1 to 4, characterized in that pressures of up to 4.55 kg / cm ² are used and there is no externally added or recycled hydrogen. 6. The method according to claim 5, characterized in that temperatures of 450 to 580 ° C and space air velocity ei from 0.1 to 1 V / V / hour be used. 7. Process according to Claims 1 to 6, characterized in that the starting material is at least is treated up to a Rescarch octane number (without addition) of 100. 8. Process according to Claims 1 to 7, characterized in that the starting material is non-aromatic Hydrocarbons with 5 to 7 carbon atoms or one of these hydrocarbons, predominantly containing mixture and in particular a straight-run distillate and / or a catalytic one Reformat, preferably a platformat, is used. 9. The method according to claim 8, characterized in that the catalytic ^ reformate in the Way is used as a starting material that the reformate by distillation or solvent extraction in a lower boiling and a higher boiling portion or in raffinate and extract is separated, then only the lower-boiling portion or the raffinate is subjected to the treatment and the resulting product then optionally with the higher-boiling portion or mixed with the extract or with other components with a high octane number will. O 909 689/522 12.