PL196901B1 - Method of selectively alkylating naphthalene and/or monoalkylnaphthalene - Google Patents

Abstract

A method of selective alkylation of naphthalene and / or monoalkyl naphthalene with a C1-C4 alkylating agent, using a zeolite catalyst characterized in that the reaction is towards isomers having substituents on the same naphthalene ring are carried out using a broad porosity zeolite catalyst containing metal ions in addition to hydrogen ions.

Description

(21) Filing Number: 350700 ^{(51) Int.Cl.}

C07C 15/24 (2006.01) C07C 2/54 (2006.01)

Patent Office of the Republic of Poland (22) Date of application: November 15, 2001 (54) Method of selective alkylation of naphthalene and / or monoalkyl naphthalene (73) Patent holder:

Industrial Chemistry Research Institute Prof. Ignacego Mościckiego, Warszawa, PL (43) Application was announced:

May 19, 2003 BUP 10/03 (72) Inventor (s):

Robert Brzozowski, Brwinów, PL Wincenty Skupiński, Warsaw, PL Stefan Szarlik, Warsaw, PL (45) The grant of the patent was announced:

29.02.2008 WUP 02/08 (74) Representative:

Anna Królikowska,

Industrial Chemistry Research Institute, Prof. I. Mościcki ⁽⁵⁷⁾ 1. The method of selective alkylation of naphthalene and / or monoalkyl naphthalene with a C1-C4 alkylating agent, using a zeolite catalyst, characterized in that the reaction towards obtaining isomers having substituents on the same naphthalene ring is carried out using a broad porous zeolite catalyst containing metal ions in addition to hydrogen ions.

PL 196 901 B1

Description of the invention

The present invention relates to a process for the selective alkylation of naphthalene and / or monoalkyl naphthalene to obtain a high isomeric dialkylnaphthalene (DAN) mixture with two alkyl substituents on the same naphthalene ring.

Substitution of two alkyl groups on naphthalene rings by an alkylation reaction of naphthalene and / or monoalkyl naphthalene results in a mixture of dialkyl naphthalene isomers in which the alkyl substituents may be in different positions on the same ring or on different naphthalene rings.

As catalysts in the alkylation reaction, substances of the Broensted acid (HF, H2SO4) or Lewis acid type, such as AlCl3 or BF3, and complexes, such as, for example, BF3-H3PO4, are used. In their presence, a product is obtained with a kinetic composition or similar to the composition in thermodynamic equilibrium. A kinetic or thermodynamic product is also obtained when using solid alkylation catalysts which do not have a homogeneous crystal structure, such as, for example, amorphous aluminosilicates.

There are also known methods of carrying out the naphthalene alkylation reaction by using zeolite catalysts of an acidic nature, i.e. aluminosilicates with a specific crystal structure, having defined voids and chambers inside the zeolite crystal. In addition to catalyzing the alkylation reactions, thanks to the presence of acidic centers on the surface, they show the effect of shape selectivity, which, in simplified terms, consists in the fact that as a result of steric obstacles in relation to the reactants, intermediate complexes or reaction products, related to the pore structure of the zeolite catalyst the composition of the product often differs significantly from the composition characteristic of a kinetic or thermodynamic product.

The comparison of the spatial dimensions of the dialkylnaphthalenes with the spatial dimensions of the pores of some zeolites shows that some isomers may be formed in the reaction of naphthalene alkylation inside the pores, while the formation of others is even excluded. As shown in the literature, the effect of shape selectivity in relation to dialkyl naphthalenes may be manifested by high β-selectivity, i.e. high content of 2-isomer in the monoalkylation product and 2,6- and 2,7- isomers in the mixture of dialkylnaphthalenes, as well as higher selectivity reaction to the 2,6- isomer than to the 2,7-dialkylnaphthalene isomer.

The patent literature describes methods of obtaining a mixture of dialkylnaphthalenes with a high content of 2,6-DAN isomer, i.e. with a molar ratio of 2,6- / 2,7-DAN isomers greater than 1. These issues are covered in WO 90/03961, WO 91/05751, DE 3703291. The methods described in these descriptions show that the use of a zeolite in the alkylation reaction of naphthalene or alkyl naphthalene showing the phenomenon of shape selectivity in relation to dialkyl naphthalene isomers produces a product with a high content of β, β isomers and, moreover, with a high content of isomer of 2.6 to the isomer of 2.7. This is due to steric obstacles inside the zeolite pores in relation to other spatially expanded isomers. The described methods lead to the maximum yield of dialkylnaphthalene isomers in which the alkyl substituents are located on different naphthalene rings with a predominance of the 2,6-isomer over the 2,7-dialkylnaphthalene isomer.

The Polish patent application no. P-322457 describes a method of producing a mixture of diisopropylnaphthalenes with a high content of the 2,7-isomer, thanks to the use of appropriate zeolite catalysts.

The aim of the invention was to obtain a mixture of dialkylnaphthalenes with a high content of isomers having both alkyl substituents on the same naphthalene ring, i.e. isomers

1,2-, 1,3-, 1,4-, 2,3-DAN.

It has been found that the use of a zeolite catalyst with an appropriate pore size in the naphthalene and / or monoalkylnaphthalene alkylation reaction causes the resulting mixture of dialkylnaphthalenes to contain a large number of isomers having both alkyl substituents on the same naphthalene ring.

Broad porosity zeolites have entry channels or ports to the internal empty chambers limited by 12 oxygen atoms (12-O). Their dimensions vary for different zeolites depending on the mutual arrangement of the silicate or aluminate tetrahedrons forming the zeolite crystal lattice, and thus on the shape of the window cross-section (e.g. circular or elliptical). The most commonly used broad porous zeolites are fojazites (zeolite X and Y), mordenites, beta zeolite, L zeolite, and ZSM-12 zeolite.

PL 196 901 B1

Mordenite has a network of straight channels (12-O) with an elliptical cross-section of 0.65X0.70 nm. Zeolite Y has an array of hollow chambers about 1.3 nm in diameter, accessed by empty circular windows 0.74 nm in diameter. Beta zeolite has a network of straight channels (12-O) with a diameter of 0.65 x 0.56 and perpendicular channels (12-O) with a diameter of 0.75 x 0.57 nm running sinusoidally. Zeolite L has a network of straight channels (12-O) with a diameter of 0.71 nm.

The above-mentioned broad porous zeolites in the hydrogen form show high β-selectivity and selectivity towards isomers having alkyl substituents on various naphthalene rings in the alkylation reaction.

For a zeolite catalyst to be active in the alkylation reaction, acid centers must be present on its surface. In the case of a catalyst that exhibits selectivity towards dialkylnaphthalene isomers having substituents on the same ring, it is necessary to narrow the pores and at the same time to have a high acidity of the zeolite.

In the process according to the invention, a wide porous zeolite catalyst was used, the diameter of the entrance windows was narrowed by the presence of metal ions in them.

Replacing the hydrogen ions present on the zeolite surface inside the entrance channels or windows with ions of monovalent or divalent metals reduces the effective diameter of the channel by up to 0.2 nm.

The method of selective alkylation of naphthalene and / or monoalkyl naphthalene with a C1-C4 alkylating agent using a zeolite catalyst, according to the invention, consists in that the reaction towards obtaining isomers having substituents on the same naphthalene ring is carried out using a broad porous zeolite catalyst containing in addition to hydrogen ions metal ions.

Preferably, a zeolite of the fotosite or mordenite type containing metal ions in addition to hydrogen ions is used as catalyst.

It is also preferred to use beta-type or L-type zeolite or Y-zeolite in the calcium-lanthanide form as catalysts, containing metal ions in addition to hydrogen ions.

An ion exchange method can be used to introduce metal ions into the zeolite, and such a catalyst is preferably used for the alkylation reaction.

The presence of monovalent, alkali metals inside the pores of the zeolite is beneficial as long as the hydrogen ions are present simultaneously. The alkali metal ions deactivate the zeolite acid centers.

The exchange of sodium ions present in zeolite with metals at least divalent causes that they are incorporated on the surface into the zeolite crystal lattice, and next to them, hydroxyl groups are formed, which are acid centers of the Broensted type. Examples of such metals are Ca, Mg, Cd, Zn, Fe, Co, Ni, Mn, lanthanides and also other metals.

The catalyst used in the process of the invention can be obtained by conventional ion exchange methods by washing the zeolite with an aqueous solution of the metal salt. For example, zeolite in sodium or hydrogen form can be treated with metal salts such as, for example, nitrates, halides, organic salts. It is best to ion exchange with aqueous solutions of chlorides or nitrates.

The exchange of metal ions into hydrogen ions can be carried out by known methods by washing the zeolite with solutions of mineral acids or solutions of ammonium chloride or nitrate, and then thermal decomposition of ammonium ions formed on the surface of the zeolite to hydrogen ions and ammonia.

The ion exchange can be carried out once or it can be repeated several times in order to obtain a higher degree of exchange.

In the process according to the invention, it is advantageous to use a zeolite in which several metal ions are present inside the pores, which can be achieved by washing with solutions of several metals.

Prior to ion exchange, the zeolite may be dealuminated in a known manner, e.g. by hydrothermal treatment and / or with mineral acids.

The naphthalene and / or monoalkyl naphthalene alkylation process according to the invention can be carried out in any reactor used in the alkylation processes, both with fixed and moving bed catalysts. A catalytic distillation reactor may also be used.

In the process of the invention, the alkylation of naphthalene and / or monoalkyl naphthalene is carried out under conventional alkylation conditions. The process temperature may range from 80 to about 600 ° C. Most often, the alkylation reaction is carried out in the range of 150 to 480 ° C.

PL 196 901 B1

By changing the reaction temperature, the content of the individual isomers in the product can be changed. It was found that the alkylate obtained at the lower temperature contained the most of the 1,4-isomer, while the product obtained at the higher temperature was enriched in the 2,3-isomer. In the case of steric obstacles resulting from the immediate vicinity of two large substituents (e.g. isopropyl), the product is enriched in the 1,3 isomer.

The alkylation process according to the invention can be carried out at pressures ranging from atmospheric to 10 MPa. It is preferable to pressurize to ensure that a liquid or supercritical phase is present in the reactor.

Dialkylnaphthalene isomers having substituents on the same naphthalene ring, after being separated from the reaction mixture by means of known methods, such as distillation or crystallization, are used to produce new plastics. They can be oxidized to the corresponding naphthalene dicarboxylic acids, and these in turn are used as starting materials in chemical synthesis, e.g. for the production of new polyester resins with very valuable properties. Dialkylnaphthalenes such as e.g. diisopropylnaphthalenes or di-sec-butylnaphthalenes are oxidized to the corresponding hydroperoxides and further processed to dihydroxynaphthalenes, also used in the production of new polyester resins.

The high content of the mixture of diisopropyl naphthalene isomers having both alkyl substituents on the same naphthalene ring is also advantageous when used as a solvent in printing, due to the low content of undesirable high pour point isomers.

The following examples illustrate the process of the invention to prepare a high isomeric dialkylnaphthalene mixture with two substituents on the same naphthalene ring.

Example I. Y-zeolite with a silicon modulus 6 and sodium content as Na2O 12.3%, obtained by 1-time ion exchange of the starting zeolite in the sodium form with 1N ammonium chloride solution at 80 ° C for 6 hours . After filtration, the zeolite was dried and calcined in flowing air at 550 ° C for 3 hours. 5 g of the catalyst thus obtained were poured into the metal pressure reactor, and after the temperature of the reactor stabilized at 200 ° C, dosing of the naphthalene-propylene mixture with a molar ratio of 1.5 / 1 was started at a rate of 9 g / g cat / hour. The pressure in the reactor was kept at 3 MPa.

After 1 hour, a liquid sample was taken and subjected to chromatographic analysis. The mixture of diisopropylnaphthalenes obtained by the alkylation contained 12.6% 1,3-DIPN and 31.4% 1,4-DIPN, and the total content of isomers having both substituents on the same naphthalene ring was 44.8%.

A mixture of diisopropylnaphthalenes prepared under the same conditions in the presence of an amorphous aluminosilicate contained only 14.5% of isomers having both substituents on the same naphthalene ring.

P r z x l a d II. Zeolite Y in the calcium-lanthanide form was obtained from NaY zeolite with silicon module 5. The zeolite was ion exchanged first by washing it with an aqueous solution of calcium chloride (conc. 20 g / l) at the temperature of 80 ° C for 6 hours. The zeolite was then washed with a 2% solution (calculated as lanthanum) of a hydrated ammonium lanthanide nitrate mixture which contained (calculated as oxides) 25% La2O3, 6% CeO2, 13% Pr6On and 30% Nd2O3. Ion exchange was carried out at 80 ° C for 6 hours and it was repeated three times. After filtration, the zeolite was dried and calcined. The obtained zeolite contained sodium as Na2O 2.1%, calcium (CaO) 2.2% and rare earth metals (Ln2O3) 4.9% by weight.

Alkylation of naphthalene with propylene was carried out in a pressure reactor, under conditions as in example I. The mixture of diisopropylnaphthalenes obtained in the alkylation reaction contained as much as 12.3%

1,3-DIPN and 44.0% 1,4-DIPN. The total content of isomers having both substituents on the same naphthalene ring was 56.6%.

P r x l a d III. Naphthalene alkylation with propylene was carried out using the catalyst as in Example 2 while maintaining the process temperature at 250 ° C. The obtained mixture of diisopropylnaphthalenes contained 24.5% 1,3-DIPN and 17.5% 1,4-DIPN, and the total content of isomers having both substituents on the same naphthalene ring was 42.8%.

P r x l a d IV. The alkylation of naphthalene with propylene was carried out at a temperature of 200 ° C, pressure of 3 MPa, using mordenite with a silicon module of 10 and a sodium content of 0.3% as a catalyst. The resulting mixture of diisopropylnaphthalenes contained 15.7% 1,3-DIPN and 22.8% 1,4-DIPN.

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The total content of isomers having both substituents on the same naphthalene ring was 39%.

Example 5 Alkylation of isopropylnaphthalene (with 45% 2-isomer content) with propylene was carried out at a temperature of 200 ° C, under a pressure of 2MPa with a molar ratio of isopropylnaphthalene / propylene = 2/1 in the presence of Y zeolite in the calcium-lanthanide form as in the example II. A mixture of diisopropylnaphthalenes was obtained which contained 27.6% 1,3-DIPN and 24.7% 1,4-DIPN. The total content of isomers having both substituents on the same naphthalene ring was 52.6%.

P r x l a d VI. Naphthalene alkylation was carried out using ethylene as the alkylating agent and NaY zeolite as the catalyst as in Example 1. The reaction was carried out at a temperature of 270 ° C and a pressure of 3 MPa. The obtained mixture of diethylnaphthalenes (DEN) contained 21.5% 1,3-DEN and 21.9% 1,4-DEN, the total content of isomers having both substituents on the same naphthalene ring was 49.4%.

For comparison, the product obtained under the same conditions in the presence of an amorphous aluminosilicate contained 29% of isomers with substituents on the same ring.

P r o x l a d VII. Naphthalene alkylation was carried out using methanol as the alkylating agent, NaY zeolite as catalyst as in Example 1. The reaction was carried out at a temperature of 450 ° C, under a pressure of 3MPa. The obtained mixture of dimethylnaphthalenes (DMeN) contained 32.1% 1,3-DMeN and 13.8%

1,4-DMeN. The total content of isomers having both substituents on the same naphthalene ring was 49.3%.

For comparison, the product obtained under the same conditions in the presence of ZSM-5 zeolite contained 22% of isomers with substituents on the same ring.

Claims (7)

Patent claims 1. The method of selective alkylation of naphthalene and / or monoalkyl naphthalene with a C1-C4 alkylating agent, using a zeolite catalyst, characterized in that the reaction towards obtaining isomers having substituents on the same naphthalene ring is carried out using a broad porous zeolite catalyst containing ions in addition to hydrogen ions metals. 2. The method according to p. The process of claim 1, wherein the catalyst is a photoite-type zeolite containing metal ions in addition to hydrogen ions. 3. The method according to p. The process of claim 1, wherein the catalyst is a mordenite type zeolite containing metal ions in addition to hydrogen ions. 4. The method according to p. The process of claim 1, wherein the catalyst is beta zeolite containing metal ions in addition to hydrogen ions. 5. The method according to p. The process of claim 1, wherein the catalyst is an L-type zeolite containing metal ions in addition to hydrogen ions. 6. The method according to p. The process of claim 1, wherein the catalyst is Y zeolite in the calcium-lanthanide form. 7. The method according to p. The process of claim 1, wherein the reaction is carried out using a zeolite catalyst in which metal ions have been introduced by ion exchange.