DE1468982C - Process for the alkylation of aromatic hydrocarbons - Google Patents

Description

3 4

more than 3, η means the valence of the cation M rare earths can be used in the same way to produce

and Y is a value up to 8, depending on the identity of the position of the catalyst used.

Kations M and the. Degree of hydration of the silicate. Of the other aluminosilicates, a syn-

Zeolite X is present in both sodium and thetic zeolites that have the same crystalline structure Forms of calcium available commercially; the former is for 5 as has zeolite X and is referred to as zeolite Y,

preferred the purposes of the invention. also for the production of the catalysts for the

The preferred aluminosilicate catalysts from processes of the invention have been found to be useful. the

of the zeolite class are those that have a faujasite structure. Zeolite Y differs from zeolite X in that

to have. For the production of ethylbenzene there is more silicon dioxide and less aluminum oxide

Preferred aluminosilicate catalyst containing uniform io. Due to its higher silicon dioxide content

This zeolite has a higher resistance to pore openings of at least 10 angstrom units

Diameter and an activity constant according to the hydrogen ions than the zeolite X. Another AIu-

definition below between about 500 and about minosilicate material that is suitable for catalytic

1000 has. It has been shown to be from the sodium form of sator manufacture, and is known as a mordenite

Zeolite X naturally occurring zeolite known by one of the conventional treatments.

to partially replace the sodium in a gas- The cation-exchanged aluminosilicate catalyst

shaped or liquid medium. It will sator can be used directly as a catalyst,

a medium used for this purpose, which leads to ionization or it can be combined with a suitable carrier or binding agent

of the cation can be combined without affecting the crystalline structurants. The special chemical additive

door of the zeolite. After such a handling composition of the last-mentioned material is not

As a result, the zeolite that has been exchanged for drying is also critical. However, it is necessary that that used

Water washed, dried and dehydrated. The carrier or binder under the conditions at

Dehydration creates the characteristic of which the conversion reaction is carried out,

System of open pores, channels or cavities in the thermally resistant. So solid porous ad-

crystalline aluminosilicates. 25 sorbents, carriers and support materials of the type

As a result of the above treatment, as it has been used so far in catalytic modes of operation

with rare earth exchanged aluminosilicate in det, in combination with the crystalline,

whose structure rare earth cations are used in place of cation-exchanged aluminosilicate

Sodium ions have entered. The sodium content of the den.

activated catalyst is therefore a measure of the full understanding in the process according to the invention of cation exchange. The used cation-exchanged aluminosilicate catalyst The catalyst used in the invention may be in the form of a fine powder or Up to 5 percent by weight and preferably below it can be in the form of pellets with a size of at -1 Percent by weight of sodium after such a game, for example, have about 1.6 to 3.2 mm, the z. B. by Treatment. It should also be noted that the pelletizing of the crystalline Ahiminosüicats with a Pore size of the suitable rare earth exchanged binder such as clay have been obtained. Catalyst in the range of 6 to 15 Å and preferred A test method has been developed to determine the wise in the range of about 10 to 13 Å in diameter activity of the catalysts for the process of located. Measure Invention. When performing the test

The rare earth cations can be fed η-hexane from the salt 40 to a reactor which contains the catalyst to be investigated into a single metal or preferably from mixtures. The Fließgeschen of metals, z. B. a rare earth chloride speed of η-hexane, the size of the catalysis or didymium chlorides originate. Such a Gemizer sample and the temperature in the reactor are usually preselected as a rare earth chloride to denote conversion levels in the range of solution; below this, in particular, 5 to 50 percent by weight is obtained below. The hexane is fed to the reactor, a mixture of rare earth chlorides, until the catalyst hexane, which is essentially composed of the chlorides in a ratio (volume basis) about 4, is obtained. At this time lanthanum, cerium, praseodymium and neodymium with lower amounts of samarium, gadolinium and yttrium are sampled and analyzed by gas chromatography,
stands. This solution is commercially available and contains 50 The cleavage of η-hexane, which is determined by a chromatographic analysis of the chlorides of the rare earths in the following graphic analysis, has the Andean composition: 48 percent by weight cerium (as if a reaction took the first Order or pseudo-CeO ₂ ), 24 percent by weight lanthanum (as La ₂ O ₃ ), first order converted into a reaction rate _{-5 percent by weight praseodymium (as Pr 6} O ₁₁ ), 17 constant. A few percent by weight of neodymium (as Nd ₂ O ₃ ), 3 percent by weight of tests and faulty samples may be required to select particularly samarium (as Sm ₂ O ₃ ), 2 percent by weight of gaddene conditions. As a general rule, linium (as Gd ₂ O ₃ ), 0.2 percent by weight yttrium (as the space velocity and temperature Y ₂ O ₃ ) and 0.8 percent by weight of other rare earths can be varied until the conversion in the pre-oxide. Didymium chloride is also a mixture from the specified range. It consists of the following deposition at low conversion, should led to rare earths, determined as oxides; 45 until the severity of the reaction conditions is reduced, 46 percent by weight of lanthanum, 1 to 2 percent by weight. The value obtained is normalized or stan-cerium, 9 to 10 percent by weight praseodymium, 32 to dardized by calculating the reaction rate by 33 percent by weight neodymium, 5 to 6 percent by weight 65 constant for a conventional silicon samarium, 3 to 4 percent by weight gadolinium, dioxide -Aluminum oxide catalyst, which contains about 10 Ge-0.4 percent by weight of yttrium and 1 to 2 percent by weight of aluminum oxide and a CAT percent of other rare earths. Has other mixtures of Α activity of 46 (described in National Petro-

Leum News, Vol. 36, Page PR 537, August 2, 1944). Such a catalyst is hereinafter referred to as a 46-Al-silica-alumina catalyst. This value is then corrected to 538 ° C using an Arrhenius equation if the test was carried out at a different temperature. The results are therefore reported as relative rate constants at 538 ⁰ C. :

The ranges of operating conditions for this * ° Test are as follows:

Temperature in the reactor .. 371 to 538 ° C

Hourly room flows ¹ p

ming speed:

■ the liquid 0.2 to 60 V / V / hour,

n-hexane flow rate. ·. 2 to 30 cm ³ / hour,

Catalyst volume in
Reactor 0.5 to 10 cm ³ .

The test conditions are usually chosen so that the operating time is between 15 seconds and 30 minutes and is preferably between 30 seconds and 15 minutes.

The aluminosilicate catalysts used in the process of the invention are prepared so that they have sufficient activity to allow low temperature alkylation with high conversion. A catalyst with a relative activity constant greater than 10 and preferably greater than 50, in accordance with the test described above, results in an effective alkylation in a tortous manner at temperatures below 316 ° C and hourly liquid space velocities of 5 to 25. For the production of ethylbenzene, the aluminosilicate catalyst used should have an activity constant of about 500 and about 1000. It is particularly preferred that in the process Catalysts used according to the invention have an activity constant greater than 1500.

The table below shows a comparison of the reaction rate constants for aluminosilicate catalysts, the different weight percentages of sodium after the acid and base exchange contained in the material, with silica-alumina serving as the base. ...... ·.

- From the table below it can be seen that the relative reaction rate constant is reversed to that in the remaining ^catalyst: increased amount of sodium. For example, a residual sodium ion content of less than 0.7 percent by weight in the catalyst gives a reaction rate constant of 4000.

■ An acid mordenite with a low sodium content also leads to a high reaction rate constant.

The operating conditions used in the method according to the invention, such as the temperature, the pressure, the space velocity, the molar ratio of the reactants and the presence of inert diluents, are on

■ Hand of the exemplary embodiments further explained.

Table I.
Cracking of n-hexane

Na content Activity catalyst Weight constant percent at 538 ° C Silica Aluminum oxide ¹ ) .. 1.0 (Base) Sodium zeolite X 14.4 1 with rare earths exchanged zeolite X 0.39 4100.0 with rare earths exchanged zeolite X 0.52 4000.0 with rare earths exchanged zeolite X 0.74 2400.0 Acid mordenite 600.0 Acid zeolite Y 1.22 570.0 with rare earths exchanged zeolite X 1.7 320.0 with rare earths exchanged zeolite X 2.7 72.0 with rare earths exchanged zeolite X 6.2 10.2

P) This conventional catalyst, which is assigned an activity of 1.0, gives 13.0% conversion of normal hexane at 538 ° C. using a 1.5 cm ³ catalyst with a grain size of about 0.25 to 0.6 mm a gas flow rate of 10 cm ³ / min helium, saturated with n-hexane vapors at room temperature and pressure, the instantaneous conversion being measured in the fifth minute of the operating time.

Table II

Comparison of the catalyst activity
in the alkylation of benzene with ethylene

Conditions:

Temperature 213 ° C

Pressure atmospheric

Benzene-ethylene ratio (molar) 12: 1
Benzene space velocity,
Volume of benzene / volume
Catalyst / hour 12

With rare earths
exchanged
Zeolite XO Silicon
dioxide-
Ainmininm-
oxide Operating time, min ...
Product analysis,
Weight percent
benzene
Ethylbenzene ...
Other alkyl
benzenes ^)
Conversion of
Ethylene to ethyl
benzene,% 90
91.2
8.4
0.4
100.0
91.5 90
100.0
0.0
0.0
100.0
0.0

O 26.5 percent by weight (SE) ₂ O ₃ ; 0.22 percent by weight Na,

13-X zeolite.
( ^a ) Diethylbenzenes, and toluene.

example 1

The high conversion achieved by a rare earth exchanged aluminosilicate catalyst is described below for the alkylation of benzene with ethylene. Like in the Table II above, occurred in the presence of a conventional silica-alumina cracking catalyst with an activity index of 46, benzene does not react with ethylene at temperatures of about 213 ° C. In contrast, benzene and ethylene react when they interact with the catalyst are brought into contact according to the invention, with the formation of ethylbenzene and others Alkylbenzenes, the conversion of ethylene to ethylbenzene being of the order of 90%.

4V

~~ example 2

The alkylation of benzene with propylene to form cumene occurs above that with rare earths exchanged aluminosilicate catalyst similar to the benzene-ethylene reaction, the operating temperature ranging from about 38 to 316 ° C. As an an example the following experiment was carried out over an extended period of time in a fixed bed reactor atmospheric pressure: Benzene and propylene were carried out at a molar ratio of 3: 1 and with a benzene hourly space velocity of 2 to form cumene and others Alkylation products, e.g. B. diisopropylbenzene reacted.

Table III

Vapor phase alkylation of benzene-propylene
over a rare earth catalyst

Operating time, min. 50
Temperature, ° C 149

Product composition,
Weight percent

Cumene

75
149

other

... 9.0
... 0.3
Total 9.3

7.5
0.5

115
227

23.0
9.5

150
227

10.5
6.5

8.0 32.5 17.0

55

Example 3

Benzene was alkylated with ethyl chloride at relatively low temperatures.

In the comparison with a conventional silica-Aluminiumoxydkatalysator the catalyst used according to the method of the invention showed high activity listed below at a temperature of 218 ⁰ C and atmospheric pressure, wherein the molar ratio of benzene to ethyl chloride 12: 1. _j

Table IV

Comparison of the catalytic activity
in the alkylation of benzene with ethyl chloride

Operating time, min. 50 100 200 350

Ethylbenzene in

the products,

Weight percent:
with rare
Earth exchanged

Zeolite .... 5.5 7.2 8.2 8.2 silica-aluminum
oxide 0.3 0.3 - -

From the above data it can be seen that the activity of the rare earth aluminosilicate is much higher than that of the silica-alumina. The alkylation of benzene with ethyl chloride can be carried out at a temperature of 38 to 316 ° C. _Λ

Example 4

At a temperature of 218 ° C and atmospheric pressure, naphthalene was combined with propylene Formation of isopropylnaphthalene alkylated.

Table V

Operating time,
Minutes

50
100
150

Product composition,

Weight percent
Isopropyl naphthalene

18.5
14.0
11.0

Other

1.5
1.0
0.5

total

20.0
15.0
11.5

40

45 The hourly space velocity of naphthalene was about 1 with a naphthalene to propylene ratio of about 3: 1. The other alkylated products of this reaction were primarily di- and triisopropylnaphthalenes.

Comparative experiments

Comparative tests were carried out using benzene with ethylene among those described below Alkylation conditions in the presence of various catalysts including by rare Earth-exchanged zeolite X (SEX), with rare earth-exchanged zeolite Y (SEY) Hydrogen exchanged zeolite Y (HY), sodium zeolite X (NaX, Linde 13X), calcium zeolite X (CaX, Linde 10X), zeolite replaced by magnesium X (MgX) and magnesium exchanged zeolite Y (MgY). the Examples were carried out as follows:

A non-calcined sample of the above aluminosilicates (0.6 to 1.25, 2.36 to 1.17 mm grain size) was diluted with annealed quartz particles (2.36 to 1.17 mm grain size) to 5 ml and in a electrically heated, tubular reactor made of refractory glass. After calcining After the catalyst sample, the reactor and the catalyst bed were flushed with nitrogen for 15 minutes then brought to the reaction temperature. The nitrogen supply was turned off and

209 585/525

ίο

the respondents, d. H. Ethylene and benzene, added in the appropriate ratio.

The conversions given in the table below correspond to those in a sample with an operating time of 135 minutes, using the various specified aluminosilicates were obtained under the given reaction conditions.

table

temperature Pressure I. • Befazol'ethylene- ■■ " ...., Conversion of catalyst v. y * j ,. 4 ratio ■ LHSV *) Ethylene to ethyl 177 atmospheric ., ·. (molar) ·. _ _ ■ benzene in ° / o SEX 177 atmospheric 12th 5.4 67 HY 177 atmospheric 12th 5.4 65 SEY 218 atmospheric 12th 5.4 58 NaX (13X) 218 to 316 atmospheric 12th 13.6 none NaX (13X) 218 atmospheric 5 3.4 none CaX (10X) 177 to 218 atmospheric 12th 13.6 none CaX (10X) 177 to 218 atmospheric 12th 6.5 none MgX 177 to 218 atmospheric 12th 7.2 none MgY 12th 5.2 none

*) Room flow rate / hours, liquid.

From these comparative values it can be seen that those to be used in the method of the invention, by rare earth exchanged zeolites X (SEX) as well as the rare earth exchanged zeolites Y (SEY) and the hydrogen exchanged zeolites Y (HY) are highly effective catalysts for the Alkylation of aromatics are and an extraordinarily high conversion of ethylene to ethylbenzene cause. The other crystalline aluminosilicates (NaX, CaX, MgX, MgY) are under the same conditions or those due to the higher reaction temperature and a lower space flow velocity were even cheaper, ineffective, d. That is, there was no conversion of ethylene to ethylbenzene.

Claims (1)

1 2 'Activity depends on either the extent of the metal claim: exchange within the aluminosilicate catalyst with rare earth metals or with hydrogen or Process for the alkylation of aromatic from both processes. Those with rare earths Hydrocarbons with olefins, alkylhalogeni- 5 exchanged aluminosilicates and those with water den or alcohols at elevated temperatures' have exchanged substances, as have the com- and in the presence of a cation-exchanged combination of rare earth and hydrogen crystalline aluminosilicates of a uniform cation-exchanged aluminosilicate catalysts Pore size from 6 to 15 Å diameter as a catalytic converter. Particularly advantageous for the alkylation of Analyzers, characterized in that io aromatics according to the process of the invention the alkylation in the presence of alumi- wiesen. nosilicates whose cations are replaced by rare earths and / or hydrogen are exchanged, with Tem- can, it is aromatic compounds, temperatures of about 38 to 316 ° C. such as benzenes, naphthalenes or anthracenes and sub- 15 substituted derivatives thereof; alkyl substituted aroma ■: th, for example toluene, xylene and their homologues, '. . are favored. Furthermore, other non- The invention relates to a process for alkylating polar substituent groups, which may also be bound to the nucleus of aromatic hydrocarbons with olefins, of the aromatic ring; or tert-butyl, the cyclohexyl, methylcyclohexyl, th crystalline aluminosilicates of a uniform cyclopentyl, bicyclohexyl, cycloalkyl group or _Λ pore sizes of 6 to 15 Å diameter as catalyst aryl groups, such as phenyl or naphthyl.
sators. The preferred acylating agents are olefins. In the process of the invention, the alkylation is, for example, ethylene, propylene or dodecylene, and of aromatic hydrocarbons in the presence of alkyl halides or alcohols; the alkyl portion of those carried out by catalysts made from synthetic same contains 1 to 20 carbon atoms. However, numerous other acyclic compounds can also be produced by naturally occurring aluminosilicates; the 30 alkylating agents are used. It has been found that aluminosilicates of the kind exhibit high catalytic properties that polymerize as well as side reaction activity in the alkylation of aromatic ions of the alkylating agent to the lowest level of hydrocarbons. . In US Pat. No. 2,904,607, the introduction of the reactants in the drive for the alkylation of aromatic carbons is regulated in the reactor. Thus the compound to be alkylated hydrogen with olefins is described, in which this is expediently introduced first and saturated with the catalyst feedstock in the presence of a crystalline metal before the alkylating agent is added to the metallic aluminosilicates with a uniform pore reactor. size of 6 to 15 Å at a temperature of about The alkylation process according to the invention 149 to 445 ° C is brought into contact. 40 becomes at temperatures not higher than 316 ° C In the US Pat. No. 2,971,903 an alumino is carried out, which causes many undesirable reactions Silicate catalyst for hydrocarbon conversion such as breakdown and formation of tarry development described for cracking processes, reforming residues, which in the catalytic alkylation process, the aromatization, isomerization, poly of hydrocarbons at higher temperatures merization and being suitable for alkylation processes 45 occur. As a result of the high should and the conversion of the sodium form of an activity, the aluminum used according to the invention The alkylation can also be carried out in aluminosilicate with suitable metal salts will provide. Carried out in the presence of inert diluents These known processes or catalysts are produced. proved for the alkylation of aromatic carbons. The naturally occurring or syn- lenhydrogen with olefins, alkyl halides or thetic aluminosilicates for the production of the alkyl Alcohols are used for the process as ineffective or because of insufficient precipitation catalyst, spoil as unsatisfactory. Among the usable naturally occurring critical The object of the invention is to create a verstalline aluminosilicates include z. B. Faujasite, for the alkylation of aromatic carbon heulandite, clinoptilolite, mordenite and dachiardite. Hydrogen, in which the desired alkylation- These silicates have the ability of benzene and products are obtained in high yield. larger aromatic hydrocarbons to be adsorbed According to the invention, this object is thereby achieved. solves that the alkylation in the presence of aluminum One of the crystalline aluminosilicates, 'that with minosilicates, the cations of which can be used by the rare earth and / 60 methods of the invention or hydrogen are exchanged, at temperatures the synthetic faujasite referred to as zeolite X; from about 38 to 316 ° C. this can, expressed as molar ratios of It has been found that the use of an aluminum oxide is illustrated in the following manner minosilicate catalyst, the cations of which become rare: Earth and / or hydrogen are exchanged, a 65 high yield of alkylation products produced, ins- ^{1> υ} ±. ^υ ' ^{2 Μ} ± ^υ · ^Α1 * ^υ * · ² ' ⁵ ± ^υ ' ^{3 blU} * ■ ^{γ Η} » ^υ especially at low temperatures and both in ⁿ liquid as well as mixed phases. The level of M herein is a cation with a valence of not