DE2261461A1 - METHOD OF TREATING A HYDROCARBON MIXTURE - Google Patents

Description

Registration number 2468 D

^sen · - Dr- E. A ^ smann DiM

p ° £ ^F "* ^un ? ^{eteIn sen} · - Dr- E. A ^ smann MLKoemgsbargar-DirM. f fiys. H. Holzbauer br. 1-. Zuriiot.i.) j _Jn _

Patent attorneys
β Munich 2, Bräuhausstraße 4 /: ί |

STAMI CARBON BV, HEERLEN (the Netherlands ) Process for treating a hydrocarbon gas in 1 sche.s

The invention relates to a method for treating a hydrocarbon mixture at elevated temperature and possibly at elevated pressure with a cylinder and catalyst containing molybdenum oxides.

It is known that an alkylene is used at elevated temperature and possibly at elevated pressure with a catalyst containing tin and molybdenum oxides treated, the catalyst alternating with a gaseous mixture, which in addition to the alkylene to be converted and steam relatively little or at all contains no oxygen, and with an alkylene-free, relatively oxygen-rich Gas mixture is brought into contact. This process is used for the reaction of n-alkylenes, for cycloalkylenes and for mixtures of both Substances in the corresponding alkanones.

It has now been found that alkanes are not converted and iso-alkylenes dimer and trimerize only to a small extent if they occur the manner described above with a tin and molybdenum oxide containing Catalyst are brought into contact.

According to the invention, these properties of the catalyst are used to achieve a separation between at least one hydrocarbon selected from alkanes and / or isoalkylenes and at least one hydrocarbon selected from n-alkylenes and / or cycloalkylenes.

Isoalkylenes are to be understood here as meaning those alkylenes whose Double bond between a tertiary carbon atom and a terminal one

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BAt)

C atom such as isobutylene and isopentylon; under n-AikyIonen liier are all n-alkylenes with more than two carbon atoms to understand, such as propylene, butylene-1, butylene-2, heptylene-3 and 3, 3-dimethyl-butylene -1.

As is known, show hydrocarbon mixtures which are apart from alkyls and / or cycloalkylenes also contain alkanes, a narrow boiling range, the constituent components not being easily separated from one another are separate. Is now such a hydrocarbon mixture, at least that a hydrocarbon selected from alkanes and / or isoalkylenes and at least a hydrocarbon chosen from n-alkylenes and / or CycioalkyIonen contains, in the manner described above with a tin and molybdenum-containing When the catalyst is brought into contact, the hydrocarbons are the last said group at least partially converted into the corresponding alkanones. Because the resulting alkanones have a much higher boiling point than the unreacted hydrocarbons is easily a separation between possible for them, e.g. by condensing and / or absorbing the reaction product and then the alkanones are separated by rectification.

The method of the present invention is useful for separating, among other things the n-alkylenes and cycloalkylenes of alkanes, which are obtained in hydrocarbon mixtures obtained by rectifying a slightly hydrogenated cracked gasoline available. The process is also suitable for the deposition of Isobutylene from cis- and / or trans-butylene, as they are in hydrocarbon mixtures, e.g. the C fraction, formed during thermal or catalytic cracking or the isomerization of hydrocarbons. It will the cis and / or trans compound converted into butanone, while isobutylene dimerized and trimerized to a small extent.

It should also be noted that the hydrocarbons not converted to alkanones can optionally be returned to the reaction zone.

The invention will now be explained in more detail with the aid of two examples.

The experiments took place by passing a mixture of hydrocarbons and steam, as well as air and steam, alternately at atmospheric pressure _{over a SnO 0 -MoO -SiO.-j catalyst.}

The catalysts used were described in accordance with the procedure in German patent application no. P 2.055.529.7 prepared under catalyst "A" and showed the following composition:

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Catalyst ¹ C ¹ : 41% by weight SnO, 36% by weight MoO and 23% by weight SiO ₀ ;

2 o 2t

Catalyst ¹ E ': 50% by weight SnO ₀ , 32% by weight MoO "and 18% by weight SiO ₀ .

& f ο 2

The preparation of the catalyst ¹ C 'took place as follows:

2 -1 0.76 kg of silicon dioxide (AEROSIL, specific surface area 200 mg) were dissolved in a solution of 2.66 kg of SnCl ₀ . 5 aq. Suspended in 30 liters of water. Then 4.6 kg of urea were added, after which the suspension was boiled with thorough stirring until the pH had risen from a value of about 0.5 to 2.2 over a period of 24 hours. The suspension was then cooled, the pH increasing further to a value of 3. 1.38 kg of MoO were added to the suspension, after which the suspension was stirred for a further 2 hours. The solid material was then centrifuged off from the liquid, washed and dried. The dry mass was compressed to form cylindrical tablets 3 mm in cross section and 3 mm long. After calcination of the tablets at a temperature of 450 ° C., steam was passed over at this temperature for 16 hours. The finely distributed zinc oxide is covered with a thin layer of molybdenum oxide.

The preparation of the catalyst ¹ E 'was carried out in a corresponding manner. ■

Example I.

Oxidation of hydrocarbon fractions of slightly increased crackbenain

Table I summarizes the results of the oxidation of three cracked fractions. .

Table I.

No. of the partial pressure in at Kata- R Temp. Implementation of effect test -; lysa- -1 ο alkylenes too grad

KW HO N ₂ tor alkanones in%

1 9.19 0.42 0.39 C 250 230 17> 37

2 0.10 0.47 0.43 C 250 230 15> 31

3 0.12 0.44 0.44 C 200 230 10> 38

R = space velocity

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In experiment 1, slightly hydrogenated cracked gasoline (boiling range 33-41 C) assumed which fraction contained useful components for alkanone formation: 3 methylbutylene-1, 2 methylbutylene-2, pentylene-1, Pentylene-2 and cyclopentylene, a total of 24% of the feed amount; the rest were saturated or doubly unsaturated.

In experiment 2, a fraction of a slightly hydrogenated cracked gasoline with a boiling range of 45-51 ° C. was assumed, which was found to be useful Components for alkanone formation contained: 2 methylbutylene-1, pentylene-1, pentylene-2, and cyclopentylene, a total of 41% of the fraction; the rest was saturated or doubly unsaturated.

In experiment 3, a fraction of a slightly hydrogenated cracked gasoline with a boiling range between 25 and 38 ° C was assumed. This faction contained as components useful for alkanone formation; Pentylene-1, trans-pentylene-2 and cis-pentylene-2, a total of 72.5% of the fraction; the rest was also saturated or doubly unsaturated.

The resulting alkanones are in experiments 1 and 2; 3-methylbutanone-2, Pentanone-2, pentanone-3, cyclopentanone and acetone and in the experiment .3: pentanone-2 and pentanone-3.

Example II

Oxidation of Gemischen_yon ^ Trans-_and _e Isobuty.l§n Table II contains an overview of Oxydationsergebnisae of mixtures of trans and isobutylene.

Table II

Partial pressure
in at

^C 4V ^C 4 ^H 8 ~ ^H 2 °
trans iso

Catal
gate

Temp. Conversion of o-transbutylene to butanone

Conversion of isobutylene to di ^ and tri-iso-butylene

0.30 0.0 0.70 E 110 230 21.2

0.29 0.01 0.70 E 110 230 19.7

0.27 0.031 0.70 E 110 230 19.7

0.15 0.15 0.70 E 110 230 23.6

0.3 0.5 3.5

R =! Running speed

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Looking at the results of the experiments in Table II so is it is clear that the method according to the invention is excellent for processing of the C. fraction, formed after the cracking of naphtha butadiene has been removed from this gasoline fraction. The crowds present on butylene-1 and butylene-2 (both in the cis and in the trans figuration) are then converted to butanone, the isobutylon oligomerized to one small part and the saturated hydrocarbons are unreacted let through. The butanone can easily be removed from the remaining part by condensation or absorption with subsequent fractional distillation separate.

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Claims (2)

PATENT CLAIMS . Process for treating a hydrocarbon mixture at elevated temperature and possibly elevated pressure with a catalyst containing tin and molybdenum oxides, which alternates with a gaseous mixture containing, apart from hydrocarbons and steam, relatively little or no oxygen at all, and with an anem hydrocarbon-free, relatively oxygen-rich gas mixture is brought into contact, characterized in that the hydrocarbon mixture consists of at least one alkylene and / or isoalkylene and of at least one n-alkylene and / or cycloalkylene, the hydrocarbons of the last-mentioned group being at least partially converted into the corresponding alkanones and that the alkanones thus obtained are separated from the unreacted hydrocarbons. 2. The method according to claim 1, characterized in that the resulting Alkanones are separated from the unreacted hydrocarbons, by condensing and / or absorbing the reaction product and then rectifies the condensate or absorbate. 309826/1195