The method of producing lactam

 

(57) Abstract:

The invention relates to the production of aliphatic lactams from dinitriles. The method comprises two stages, the first of which shall providerone of dinitrile hydrogen heterogeneous catalyst to the corresponding aminonitriles, and in the second stage, carry out the hydrolysis with water in the vapor phase in the presence of a catalyst with or without simultaneous cyclization to the lactam. Intermediate aminonitriles clear of the water and/or solvent and organic impurities by distillation under reduced pressure. As a catalyst for hydrolysis step can be used zeolite, silicate or other molecular sieve acidic or amphoteric type, or a metal phosphate of General formula (PO4)nHh(Imp)pwhere (Imp) - impregnating compound based on alkali or alkaline earth metal. As a result, increase the yield and purity of the final product. 14 C.p. f-crystals.

The present invention relates to a process for the preparation of lactams from dinitriles.

Aliphatic lactams such as Epsilon-caprolactam, are the main raw material for producing polyamides (polyamide-6 from caprolactam).

Industrial is in the presence of a strong acid, such as sulfuric acid, and the excess is then neutralized. This method has a great disadvantage in that form very large quantities of ammonium sulfate up to several tons per ton of caprolactam obtained.

Another way to get these lactams is to implement partial hydrogenation of dinitriles to the appropriate aminonitriles, mainly adiponitrile to aminoacetonitrile, then carefully cleaned aminonitriles from all impurities, such as various imine or amines formed during the hydrogenation, and the diamine, and polimerizuet to polyamide purified aminocaproate.

The above method is attractive at first glance, however, requires thorough cleaning of aminonitriles. In fact, polymerization is possible only if aminonitriles does not contain diamine, and especially different imine or amines as by-products, which limit the degree of polymerization and cause the appearance of stains and the formation of branched polymer. However, the proximity of the properties aminonitriles to remove Eminem or amines and, moreover, the existence of equilibrium between different forms of products de the, designed to transform Iminov, before deleting them. So, in the WIPO patent-And - 9316984 propose to add to the processed mixture to 10 wt.% carbonyl compound such as aldehyde or ketone. In the WIPO patent-And-9314064 recommended to introduce into the reaction mixture before distillation of the methylene compound, such as malonitrile, Dicyclopentadiene, cyclopentadiene, nitromethane, nitroethane, inden. Introduction connections to the already complex mixture is a disadvantage of this method.

The present invention relates to a process for the preparation of lactam, uniting two stages, one of which is providerone of dinitrile to aminonitriles, the other hydrolysis by cyclization of aminonitriles held only one cleanup operation.

More specifically, the method of producing lactam is that:

- hydronaut aliphatic dinitrile to aminonitriles using hydrogen and a catalyst;

- distilled received aminonitriles to keep the content of dinitrile less than or equal to 10 wt.%, and the content of by-products with imino - or aminopentyl less than or equal to 10 wt.%;

- surpassed aminonitriles in the vapor phase is injected into the interaction with water in the Pris the obsession of dinitrile 0,0050%, but it's a minor content was achieved at the expense of quantity of processed aminonitriles, because you would have to separate the intermediate fraction distillation, suitable for recirculatory, a new operation providerone. Therefore usually prefer to refer to the stage of hydrolysis by cyclization of aminonitriles containing 0.005-5 wt.% dinitrile.

Usually by distillation is difficult to reduce aminonitriles the total content of other by-products to less than 0.2%, but since this value is not lower critical limit for the method of the invention, at the stage of hydrolysis by cyclization using aminonitriles containing 0.2 - 5 wt.% products with imino - or aminopentyl.

Corresponding to the used dinitrile diamine does not prevent hydrolysis step with cyclization. In the present invention it is not viewed as above-mentioned by-product with aminopentyl.

Aliphatic dinitrile, which can be used in the first stage of the method of the invention, are denitely General formula (I):

NC - R - CN (I)

in which R denotes alkylenes or alkenylamine, a linear or branched group with 1-12 carbon atoms.

Pragmatical 1 6 carbon atoms.

As examples of such dinitriles can be called adiponitrile, methylglutaronitrile, ethylsuccinate, malononitrile, succinonitrile and glutaronitrile and their mixtures, for example mixtures of adiponitrile and/or methylglutaronitrile and/or ethylsuccinate, which may be formed in the same method of synthesis of adiponitrile.

Almost dinitrile where R=(CH2)4are the most typical, as they correspond to adiponitrile (ADN), used in this way.

Providerone of dinitrile to the appropriate aminonitriles using hydrogen is usually carried out in the presence of a catalyst based on Raney Nickel, Raney cobalt and Raney Nickel or Raney cobalt containing an activating element selected among the elements of groups IV b, VI b, VII b and VIII of the periodic system of the elements, as published in the Handbook of Chemistry and Physics, 51st ed. (1970 - 1971), and a strong inorganic bases, derived from alkali or alkaline earth metal.

Source environment for hydrogenation includes at least one solvent capable of at least partially solubilisate dinitrile as gidrirovanny is on water quantity, at least 0.5 wt.% from all the liquid compounds of the reaction medium.

In addition to the water or instead of water, the reaction medium may contain at least one other solvent, such as alcohol and/or amide and/or amine and/or ammonia. Mostly are alkanols, such as methanol, ethanol, propan-1-ol, propan-2-ol and butane-1-ol; diols, such as ethylene glycol and propylene glycol; polyols or mixtures of the aforementioned alcohols. If the solvent is an amide, then choose, in particular, dimethylformamide and dimethylacetamide. Of the amines that can be used as a solvent, can be applied, for example, diamine or aminonitriles corresponding to dinitrile that hydronaut.

If you use water, the solvent exceeds by weight in 2-4 times the weight of the water.

According to a preferred variant implementation stage providerone of dinitrile, the initial reaction medium contains a diamine and/or aminonitriles, which may be formed from gidrirovannogo of dinitrile and neprevyshenie dinitrile in the amount of 80 to 99.5%.

The degree of transformation of dinitrile is preferably at least 70%.

Strong inorganic base outputfile choose among hydroxides, carbonates and alkanoates alkali metal. Mainly used strong inorganic base is chosen among the following compounds: LiOH, NaOH, KOH, RbOH, CsOH and mixtures thereof.

Almost often use NaOH and KOH, which provide a good compromise between cost and result, although RbOH and CsOH can give very good results.

The reaction medium has a composition varying depending on the type of method.

So, if the process is carried out periodically, for example, in the laboratory or in small cyclical industries, the original medium is gradually enriched by aminonitriles and, to a lesser extent, diamine, whereas the concentration of dinitrile can either be reduced if you download the whole amount or most of the above dinitrile since providerone, or remain relatively constant if dinitrile introduced gradually during the reaction.

On the contrary, if the process is carried out continuously, the composition of the reaction medium at the outlet of the reactor depends on the selectivity of the reaction.

Water is usually present in amounts less than or equal to 20%. Preferably the water content in rederive the process average composition is determined by the ratio of selectivity to aminonitriles to the selectivity of the diamine and the rate of introduction of dinitrile.

The number of strong inorganic bases, preferably greater than or equal to 0.1 mol/kg of catalyst. Preferably it is 0.1 to 3 mol per kg of catalyst and even more preferably 0.3 to 2 mol/kg of catalyst.

The catalyst may be Raney Nickel and Raney cobalt, which contain in addition to the Nickel or cobalt and the residual amount of metal that is removed from the original alloy upon receipt of a catalyst, usually aluminium, one or more elements, often called activators, such as, for example, chromium, titanium, molybdenum, tungsten, iron, zinc. The most preferred activating elements are chromium and/or iron and/or titanium. These activators are usually present in an amount of 0-15 wt.%, preferably 0-10 wt.% by weight of Nickel.

The amount of catalyst may vary within wide limits and depends on the type of the method or from the selected reaction conditions. So, if dinitrile introduced gradually into the reaction medium, the mass ratio of catalyst/GearWay dinitrile much higher than if the whole dinitrile was introduced at the beginning of the reaction. So, you can use 0.5 to 50 wt.% catalyst in recontesting turning dinitrile output aminonitriles passes through a maximum, determined by the ratio of base/Ni or base/.

The optimal output aminonitriles at a constant degree of conversion of dinitrile depends on the nature and quantity of the activator, the amount of water in the reaction mixture and the temperature.

Stage providerone according to the invention is usually carried out at a temperature below or equal to 150oC, preferably lower than or equal to 120oC and, more preferably, less than or equal to 100oC.

More specifically, this temperature is estimated at between room temperature (about 20oC) and 100oC. Without technological problems, you can work at temperatures below 20oC, however, this is not of interest in connection with the lower productivity of the reaction.

Previously, simultaneously, or after heating in the vessel, where they spend their reaction, sets the corresponding hydrogen pressure from 1 bar (0,10 MPa) to 100 bar (10 MPa), and preferably 5 bar (0.5 MPa) 50 bar (5 MPa).

The duration of the reaction varies depending on the reaction conditions and catalyst.

When the periodic method of implementation duration of the reaction may vary from a few mine is a second form of the industrial implementation of the method, duration of course is not a constant parameter.

Before you send the under providerone aminonitriles on stage hydrolysis is necessary to remove most of the water and/or solvent, which in certain cases are present, as well as unreacted dinitrile formed diamine and the reaction by-products, such as connections imine or amine type.

This treatment can be carried out by conventional surgery distillation is preferably carried out at a pressure below atmospheric. First, distilled water and/or solvent, then the resulting diamine such as hexamethylenediamine were. After this comes aminonitriles, for example, 6-amino-cupronickel (DCA). Unreacted dinitrile can also be separated by distillation.

Obtained by this distillation aminonitriles may contain, as mentioned above, up to 10 wt.%, and preferably up to 5 wt.% dinitrile and up to 10 wt. percent, and preferably up to 5 wt.% other by-products formed during the hydrogenation of dinitrile. When dinitrile is adiponitrile, these byproducts can be in particular hexamethylenimine (GMO), aminomethyl(hexamethylendiamine) (BGG), the product of condensation of azacycloheptane with 6-amino-kapronasia [6- (6'-amino-hexamethylene-imino)hexanetriol], or, if providerone carried out in alcohol, various compounds formed by the reaction of the alcohol with an intermediate reaction products.

Stage hydrolysis by cyclization of purified aminonitriles order to obtain the corresponding lactam is in the interaction, in the vapor phase, the above-mentioned aliphatic aminonitriles General formula (I):

N C-R-CH2-NH2(II)

in which R denotes alkalinity or alkenylamine, linear or branched radical with 1-12 carbon atoms, with water, preferably in the presence of the solid catalyst.

Preferably in formula (II) aminonitriles R denotes alkalinity, linear or branched radical with 1-6 carbon atoms.

The solid catalyst can be very diverse nature. You can use a molecular sieve (crystalline compound with mikroporistogo about 3-10 angstroms), nazerite molecular sieve, the phosphate monolithic metal or oxide, acidic or amphoteric.

Molecular sieves are silicates and acidic zeolites.

Under the zeolite sovani three-dimensional connection tetrahedral units of SiO4and TO4where T denotes a trivalent element, such as aluminum, gallium, boron and iron, preferably aluminum. Most commonly used zeolites are aluminosilicate type.

In the crystal lattice of the zeolite have a system of cavities interconnected by channels of a certain diameter, which are called pores.

Zeolites can be one-dimensional, two-dimensional or three-dimensional crystal lattice.

From zeolites can be used natural zeolites, such as, for example, offretite, clinoptilolite, erionite, chabazite, filipcic.

Well established synthetic zeolites.

As examples of synthetic zeolites with one-dimensional lattice can be called, in particular, zeolite ZSM-4, zeolite L, zeolite ZSM-12, ZSM-22, ZSM-23, ZSM-48.

As examples of zeolites with a two-dimensional crystal lattice, which are used preferably, can be called a beta-zeolite, mordenite, ferrierite.

As for zeolites with three-dimensional lattice, then mostly you can specify zeolite Y, zeolite X, zeolite ZSM-5, ZSM-11, offretite.

Synthetic zeolites preferred trail
- mordenite with a molar ratio Si/Al = 5-15;

- ferrierite with molar ratio Si/Al = 3-10;

- offretite with molar ratio Si/Al = 4-8,5;

- beta zeolite with a molar ratio Si/Al = 15-25;

- Y zeolites, especially zeolite obtained after metaluminous processing (for example, hydrobromide, washing with hydrochloric acid or processing using SiCl4), mainly zeolites US-Y with molar ratio Si/Al higher than 3, preferably 6-60;

zeolite X porasitelo type with a molar ratio Si/Al = 0,7-1,5:

the zeolites ZSM - 5 or silicalite aluminum with a molar ratio Si/Al = 10-2000;

zeolite ZSM-11 with molar ratio Si/Al = 5-30.

Used in this way, the zeolites are known products described in the literature [see "Atlas of zeolites structure types, W. M. Meier and D. H. Olson, published by the Structure Commission of the International Zeolite Association (1978)].

You can use zeolites are commercially available, or synthesizing them are described in the literature methods.

You can refer to the above Atlas and mainly to obtain the following can be referenced:

zeolite L is a publication Barrer, R. M. and others, Z. Kristallogr. 128, S. 352 and subsequent (1969);

zeolite ZSM-12-on the R., Zeolites, 5, S. 349 and subsequent (1985);

zeolite ZSM-23 - U.S. patent 4076842 and article Rohrman A. S. and others, Zeolites, 5, S. 352 and subsequent (1985);

zeolite ZSM - 48 - in work Schlenker, J. L., and others, Zeolites, 5, 355 S. and subsequent (1985);

- beta zeolite in U.S. patent 3308069 and article Caullet, P. and others, Zeolites, 12, 240 C. and subsequent (1992);

- mordenite - on work Itabashi and others, Zeolites, 6, 30 C. and subsequent (1986);

- zeolites X and Y, respectively, U.S. patent 4076842 and 3130007;

zeolite ZSM -5 - U.S. patent 3702886 and article Shiralkar V. P., and others, Zeolites, 9, S. 363 and subsequent (1989);

zeolite ZSM-11 - on the work of I. D. Harrison and others, Zeolites, 7, S. 21 and subsequent (1987).

Zeolites can be used in various forms: powder, molded products, such as granules (for example, cylinders or balls), tablets, monoliths (blocks in the form of honeycomb), which is produced by extrusion, casting, pressing or any other known method. Practically in industry use of the form of granules, pellets or monoliths, which have advantages in terms of efficiency and in terms of ease of use.

The invention does not preclude the use of the binder during formation of the zeolite, for example of aluminum oxide or clay.

Whatever your chosen the classical treatments.

So, you can exchange the cations of alkali metals, subjecting the zeolite processing, which is carried out using ammonia solution and which leads therefore to the exchange of the cation of an alkaline metal ion, ammonium, then the calcination of the zeolite with ammonium ions to decompose the ammonium cation and replaced by ion H+.

The number of solution of ammonia, at least equal to the amount required for the redemption of all of the cations are alkali metal ions and ammonium. Therefore, enter at least 10-5- 510-3mol ammonia solution per gram of zeolite.

Of the silicates used mainly silicalite type I patterns similar to ZSM - II and beta-silicalite.

The term "molecular nazerite sieve, or NCMS, in this text means the molecular sieve SAPO described in U.S. patent 4440871; ELAPSO molecular sieves described in European patent A-O 159624, and some crystalline alumophosphate, metalloaluminophosphates (MeAPO), ferroaluminum (FeAPO), titanomagnetite (TAPO), described in the following patents. Crystalline alumophosphate described in U.S. patent 4310440; crystalline metalloaluminophosphates MeAPO, where Me denotes at least one metal,ne USA 4554143: titanomagnetite TAPO described in U.S. patent 4500651; other neoreality ELAPO molecular sieves are described in European patent A-O 158976 and a-0 158349.

Phosphate metal more specifically may be a metal phosphate of General formula (III):

(PO4)nHhM, (Imp)p(III)

where:

M denotes a divalent, trivalent, tetravalent or pentavalent element, selectable in groups 2A, 3b, 4B, 5B, 6b, 7b, 8, 2B, 3A, 4A and 5A of the periodic system of elements, or a mixture of several of these elements, or M=0, where M denotes some pentavalent elements;

Imp denotes impregnating the connection of the main character, formed of alkali or alkaline earth metal, or a mixture of several of these metals are associated with protivoiona to ensure electroneutrality;

"n" represents 1, 2 or 3;

"h" represents 0, 1 or 2;

"p" denotes a number from 0 to 1/3, and corresponds to the molar ratio between the impregnating compound Imp and imprintirovannymi connection (PO4)nHhM

From aminonitriles formula (II), the most important are those which lead to lactams, employees source material for obtaining polyamides-4, -5, -6, and -10, i.e., such that in the formula which the symbol R (II) is 6-amino-cupronickel (or Epsilon-cupronickel), which leads to caprolactam, the polymerization of which results in a polyamide-6.

From metals of groups 2A, 3b, 4B, 5B, 6b, 7b, 8, 2B, 3A, 4A and 5a of the periodic system of the elements is can be called beryllium, magnesium, calcium, strontium, barium, aluminum, boron, gallium, indium, yttrium; lanthanides such as lanthanum, cerium, Presidium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium; zirconium, titanium, vanadium, niobium, iron, germanium, tin, bismuth.

Among the lanthanide phosphates can distinguish the first group, which includes orthophosphate light rare earth elements, also called cerium rare earths, including lanthanum, cerium, praseodymium, neodymium, samarium and europium. These orthophosphate are dimorphic. They have a hexagonal structure and evolve to the monoclinic crystal structure, if they are heated at a temperature of 600 - 800oC.

The second group of lanthanide phosphates form the orthophosphate of gadolinium, terbium and dysprosium. These orthophosphate have the same structure as the orthophosphate cerium rare earths, but, in addition, contain a third crystal phase quadratic structure at high temperature (about 1700oC).

Of the various families mentioned above orthophosphate rare earths it is preferable to use cerium orthophosphate rare earths.

You can use the phosphates of metals of the formula (II), which are mixtures of phosphates more of the above metals or mixed phosphates of several of the above metals or mixed phosphates containing one or more of the above metals and one or more other metals, such as alkaline or alkaline earth metals.

Protivoanemi included in the formula impregnating compounds Imp are the main character. Especially you can use hydroxide, phosphate, hydrogen phosphate, dihydrophosphate-, chloride, fluoride, nitrate, benzoate, oxalate ions, and this list is not restrictive.

The molar ratio of "p" is preferably of 0.02 to 0.2.

If you refer to the common methods of obtaining phosphates (such as described in particular in "PASCAL P. Nouveau traité de chimie minerale" so X (1956), S. 821-823; and in "GMELINS Handbuch der anorganischen Chemie" (8th edition), T. 16 (C), C. 202-206 (1965)), we can distinguish two main p is state ammonium or phosphoric acid; on the other hand, dissolution of the oxide or metal carbonate (insoluble) using phosphoric acid, usually by heating, followed by presidenial.

The above phosphate obtained according to one of the specified paths, can be dried, treated with organic (such as ammonium hydroxide) or inorganic (such as a hydroxide of an alkali metal) of the Foundation and may be subjected to annealing, and these three operations can be implemented in the order shown or in a different order.

Phosphates of metals of the formula (III), for which the symbol "p" is greater than 0, can be obtained by impregnating compounds (PO4)nHhM, obtained according to one of the above methods, using a solution or suspension Imp in a volatile solvent such as preferably water.

Results the better, the more soluble the compound Imp and the more freshly prepared is the compound (PO4)nHhM.

Thus the preferred method of obtaining phosphates of the formula (II) is that:

a) carry out the synthesis of compounds (PO4)nHhM; then, preferably without isolation (PO4)nHpossible residual liquid from the resulting reaction solids;

g) dried and, if necessary, calcined.

Characteristics of the catalyst of formula (III) and especially its resistance to deactivation can be improved by annealing. The temperature of calcination is preferably 300-1000oC and preferably 400-900oC. the duration of the calcination may vary within wide limits. For information, it is usually from 1 hour to 24 hours.

Of the preferred in the method of the invention catalysts of the formula (III) can be called predominantly lanthanum phosphate; calcined phosphate of lanthanum; phosphate of lanthanum, associated with the derived caesium, rubidium or potassium: calcined cerium phosphate; phosphate of cerium associated with the connection of cesium, rubidium or potassium; samarium phosphate associated with the connection of cesium, rubidium or potassium hydroxide; aluminum phosphate; aluminum phosphate associated with the connection of cesium, rubidium or potassium hydroxide, calcined phosphate niobium; niobium phosphate associated with the connection of cesium, rubidium or potassium; calcined phosphate zirconium; zirconium phosphate, associated with the connection of cesium, rubidium or potassium.

Acidic solid oxides, which can serve as a solid cut the metals or metal oxides, modified to make them sour, especially by the impact of halogen, halide ammonium or acid, such as sulfuric acid or halogen acids. Halogen, if necessary input for acidification monolithic oxide, is preferably chlorine or fluorine.

Amphoteric monolithic oxides are amphoteric oxides with nature or those that purchase the amphoteric character in the process of retrieval method or by subsequent processing.

As non-limiting examples of acidic or amphoteric solid oxides can be called a mixture of SiO2/Al2O3, SiO2/Ga2O3; SiO2/Fe2O3; SiO2/B2O3; halogenated oxides of aluminum, such as chlorinated and fluorinated alumina; sulfated Zirconia; niobium oxide; tungsten oxide; the oxide of thorium; zirconium dioxide; titanium dioxide; cerium dioxide; silica; aluminum oxide.

Among these solid oxides aluminium oxides, which can be used as a solid catalyst for hydrolysis step with cyclization, have a very diverse structure. However, preferably chosen from the oxides of aluminum, having a specific surface area measured by BET method, of greater than or equal to 5 m2/g and even more preferably equal to 10 m2/,

Preferably the aluminum oxide used in the method according to the invention has a specific surface area equal to or below 500 m2/,

Oxides of aluminum, which can be used in the present method, are the oxides of aluminum, having a specific surface greater than or equal to 10 m2/g and less than or equal to 280 m2/g and pore volume with a diameter of more than 500 angstroms above or equal to 10 ml/100 g

Specific surface area determined by BET method, is a specific surface area determined by nitrogen adsorption in accordance with standard ASTM D 3663-78, based on the method of BRUNAUER - EMMETT - TELLER described in the periodical "The Journal of the American Society", 60, 309 (1938).

The volume of pores with a diameter of more than 500 indicates the total amount generated by all pores having a diameter above 500 This amount is measured by the method of mercury penetration, which apply the law Kelvin.

Preferably the oxides of aluminum, this first group have the volume of pores with a diameter above 500 above or equal to 20 ml/100 g or more preferably enter the percent of the surface above or equal to 50 m2/,

Oxides of aluminum, which can be used in this way are also aluminum oxide having a specific surface area of greater than or equal to 50 m2/g and less than or equal to 280 m2/g and pore volume, the diameter of which is greater than 70 angstroms, greater than or equal to 30 ml/100 g

Preferably, the oxides of aluminum, this second group had a volume of pores with a diameter above 70 above or equal to 45 ml/100 g

Also preferably, the oxides of aluminum, this second group had a specific surface area greater than or equal to 80 m2/,

Oxides of aluminum, which can be used in the present method, are also aluminum oxide having a specific surface greater than or equal to 2802/g and a total pore volume greater than or equal to 15 ml/100 g

Preferably, the oxides of aluminum, this third group have a total pore volume greater than or equal to 22 ml/100 g and more preferably higher than or equal to 30 ml/100 g

Aluminum oxide is also characterized by its acidity.

This acidity can be measured by the test of isomerization of 1-butene to 2-butene.

This test is based on the reaction of isomerization of 1-butene to a mixture of CIS-2-butene and TRANS-2-ravnovesie. It can be defined by two constants:

- theoretical equilibrium constant KT(T) determined by the calculation:

< / BR>
where [butene] (equal.) denotes the concentration of each of the isomers in equilibrium at temperature T;

real equilibrium constant K (T) determined from the result of measurements:

< / BR>
where [butene] denotes the concentration of each of the isomers at the exit of the reactor at the temperature T.

Isomerizing the ability And oxides of aluminum is determined by the activity regarding balance:

< / BR>
In practice, the test is carried out in a vapor-phase reactor operating in pulse mode, which is administered 500 mg of pulverized aluminum oxide (particle size of 400-500 μm). The aluminum oxide was incubated for 2 hours at 250oC in an atmosphere of helium supplied at a speed of 2.5 l/h. Then the alumina is brought to a temperature of 400oC and injected through the injection over him 1 ml of 1-butene in a stream of helium. Analysis of effluent gases is carried out by chromatography in gas phase and determine recuperated quantity of 1-butene and CIS - and TRANS-2-butene.

This isomerizing ability And adjusted by definition isomerizing ability obtained in those Photo above of aluminum oxide.

If the content of alkali or alkaline earth metal present in the aluminum oxide, below 60 mmol per 100 g of aluminum oxide, the higher the value of Acthe more acidic alumina.

Usually aluminum oxide is produced by dehydration of gibbsite, bayerite, nordstrandite or their mixtures. You can refer to, for example, the encyclopedia KIRK-OTHMER, so 2, S. 291-297.

Used in this way aluminum oxide can be obtained by bringing into contact of hydrated aluminum oxide in finely ground form with a stream of hot gas at a temperature of 400 - 1000oC, then maintain contact between the hydrate and gas in the course of time from a fraction of a second to 10 seconds and the Department partially digidratirovannogo of aluminum oxide from the hot gases. In this respect especially, you can reference the method described in U.S. patent 2915365.

You can also autoclaving videolooking agglomerates of aluminum oxide, in an aqueous medium, if necessary in the presence of acid, at temperatures above 100oC and preferably at 150-250oC, during preferably 1 to 20 hours, then dried and calcined.

The temperature of annealing the reg is.

In accordance with their main methods of obtaining aluminium oxides often contain sodium, the content of which is usually expressed in mass fractions of Na2About based on the weight of alumina.

The catalyst may be used in various forms such as powder, balls, food crushing, extrudates, tablets, and the shape may be, if necessary, is implemented using a binder.

First of all we are talking about the balls of aluminum oxide obtained by the method of coagulation in the drop. This type of beads may be, for example, prepared according to the method described in the European patents NN A-O 015801 and A-O 097539. Control over the porosity can be carried out according to the method described in European patent A-O 097539 by coagulation in a drop of the aqueous suspension or dispersion of alumina or of a solution of basic aluminum salts, in the form of an emulsion, which is formed of an organic phase, an aqueous phase and surface-active agent or emulsifier. The above organic phase can be hydrocarbon.

It may also be the products of crushing aluminum oxide. These products crushing can be obtained by crushing of any type of material n the filing drum) or extrudates. Control over the porosity of these fragmented products is accomplished by selecting a material based on aluminum oxide, which are crushed to produce these products.

It can also go on the extrudates of alumina. They can be obtained by kneading, and then the extrusion material based on aluminum oxide, and the above-mentioned material may be a product of the rapid dehydration of hydrargillite or gel deposition of aluminum oxide. Control over the porosity of these extrudates can be implemented by use of aluminum oxide and due to the conditions of receiving this aluminum oxide or by kneading conditions of the alumina prior to extrusion. For example, the alumina may be mixed at the time of kneading with the pore. As an example, the extrudates can be obtained by the method described in U.S. patent 3856708.

In some cases it is advisable to at least a portion of the free volume of the reactor was busy with an inert solid substance, such as quartz, with the aim of favouring evaporation and dispersion of the reactants.

As the oxides of aluminum, and in General the solid catalyst stage guy is than giving the above form, if necessary, can be implemented using a binder.

For hydrolysis by cyclization requires the presence of water. The molar ratio of water to aminonitriles that type is usually 0.5 to 50, and preferably 1-20. The higher value of this ratio is not critical for the invention, however, a higher ratio of almost no interest for economic reasons.

Aminonitriles and water can be introduced into the reactor in the form of their mixtures in the form of vapour or separately. You can pre-evaporation of the reagents, which are then sent to the mixing chamber.

You can use any inert gas as a transporting agent, such as nitrogen, helium or argon.

The temperature at which phase hydrolysis with cyclization, should be sufficient to ensure that the reagents were in the form of vapor. It is usually 200-450oC and preferably 250-400oC.

The contact time between aminonitriles and the catalyst is not critical. It may vary depending on equipment. This contact time is preferably 0.5 to 200 seconds, and more preferably 1-100 seconds.

Pressure is not critical to this study and a pressure of 0.1-20 bar.

Not exclude the use of inert under reaction conditions solvent, such as, for example, alkane, cycloalkane, aromatic hydrocarbons or their halogenated derivatives, in order to ensure the presence of a liquid phase in the reaction stream.

The resulting lactam can be cleaned, usually by distillation, prior to polymerization. This cleanup is much easier to lactam than aminonitriles. In addition, it was found that the by-products contained in aminonitriles introduced at the stage of hydrolysis, mostly decomposed during this stage and can be easily removed.

Distillation of the lactam can be done in the presence of a strong base, such as hydroxide of alkali metal, and the presence of this Foundation facilitates separating the lactam from by-products and aminonitriles, which was not browseinterval. Particularly well suited sodium hydroxide or potassium hydroxide.

The following examples illustrate the invention.

Example 1

In the reactor of stainless steel with a capacity of 3.6 liters equipped with a stirring cavitating type (rushtone cavitator), means for introducing reactants and hydrogen and system for temperature regulation, sagrajas 1,7% Cr) - 30,3 g Ni

In this example, you have to 0.4 mol of KOH/kg Ni.

After purging the reactor with nitrogen, then with hydrogen, the reaction mixture is heated to 50oC; then install a pressure of 2 MPa at this temperature with continuous addition of hydrogen. The reaction course is monitored by the absorption of hydrogen. When consumed 2.2 equivalents of hydrogen in relation to the downloaded adiponitrile, the reaction is stopped by stopping the stirring and cooling the reaction mixture. By chromatography in the vapor phase quantify residual adiponitrile (ADN) and the resulting 6-amino - cupronickel (DCA) and calculate the degree of transformation (TT) ADN and out of DCA in relation to developed ADN (RT).

Get the following results:

duration of response = 118 minutes; TT ADN = 81%; RT DCA = 60,3%.

This operation is repeated 7 times, and the combined reaction mixture, after separation of the catalyst by filtration, collected for distillation. Aminocaproate distilled at 120oC at a pressure 2660 PA using a column with a diameter of 70 mm, with a nozzle made of stainless steel, with efficiency, which corresponds to 30 theoretical plates.

The thus obtained aminocore-cupronickel;

1.5 wt.% various amines and Iminov, the main of which is 6-(6'-amino-hexamethylene-imino) hexanenitrile.

Stage hydrolysis by cyclization of the thus obtained 6 - aminocaproate (DCA) is carried out in a cylindrical reactor with a capacity of 20 ml of pericoloso glass, located vertically and provided with means for heating, holes for input and output gas flow and system administration by injection of reagents.

In this reactor sequentially load 10 ml of quartz, 1 ml of aluminum oxide in the form of a powder with a grain size distribution 400-500 microns and again 10 ml of quartz.

So loaded reactor is heated at 400oC in air flow (with flow rate of 1.5 liters/hour) for 2 hours. Then the reactor is cooled to 320oC (selected reaction temperature) and incubated in a stream of nitrogen (flow rate to 17.6 ml/min).

After that by means of the pump Inuktitut mixture of DCA with water (mass ratio of 50/50, or the molar ratio of water/AKN = 6,2). The flow rate of the injection mixture is 1,14 g/hour.

At the exit of the reactor vapors are condensed in a glass trap at room temperature.

The final reaction mixture was analyzed by chromatography in apreferendum aminoacetonitrile.

Using different methods of analysis (chromatography in the vapor phase in combination with mass spectrometry, particularly nuclear magnetic resonance) state the complete disappearance of side products in the form of amines and Iminov present in the used aminoacetonitrile.

Get these stable characteristics for the duration of the reaction 50 hours: TT DCA is 99%;

RT KPL is 98%.

Example 2

In a metal reactor equipped with a stirring cavitating type, means for introducing reactants and hydrogen and various regulatory systems, enter the following boot:

adiponitrile - 2856 kg

hexamethylenediamine were - 1151 kg

water - 588 kg

CON - 0.83 kg

the Raney-Nickel (from 1.7% Cr) - 37 kg

In this example, there is a 0.4 mol KOH/kg Ni.

Working under the conditions described in example 1. Get the following results: duration of response = 3.5 hours; TT ADN = 86%;

RT DCA = 64%.

After separation of the catalyst by filtration, about 6 kg of the reaction mixture is distilled at 120oC at a pressure 2660 PA using a column with a diameter of 75 mm, with a nozzle made of stainless steel, which has a capacity corresponding to 11 in theory is t; 0.02 wt.% adiponitrile; 0.36 wt.% diamine; to 97.1 wt.% 6-amino-cupronickel; 2.5 wt.% various amines and Iminov, the main of which is 6- (6'-amino-hexamethylene-imino) hexanenitrile.

In order to better show that the method according to the invention allows the use of on-stage hydrolysis by cyclization of relatively purified 6-amino-cupronickel, the fraction of amino-cupronickel (DCA), which surpassed add again a variety of additional impurities. So get AKN containing; 1 wt.% adiponitrile; 1 wt.% diamine; 2,5 wt. % various amines and Iminov, from which the main is 6-(6'-amino-hexamethylene-imino) hexanenitrile; 1 wt.% 1-imino-2-cyano-cyclopentane; 1 wt. % of hexamethylenimine (GMO); 1 wt.% bis-(hexamethylendiamine) (OSH); of 92.5 wt.% 6-amino-kapronasia.

Stage hydrolysis by cyclization of the thus obtained DCA is carried out in a cylindrical reactor with a capacity of 20 ml of pericoloso glass, vertical and provided with means for heating, holes for input and output gas flow and injection of reagents.

In this reactor sequentially load 3 ml quartz, 2 ml (0.87 g) aluminum oxide (u ml quartz.

So loaded reactor is heated at 400oC in air flow (with flow rate of 1.5 liters/hour) for 2 hours. Then the reactor is cooled to 320oC (selected reaction temperature) and incubated in a stream of nitrogen (flow rate of 88 ml/min).

After that by means of the pump Inuktitut mixture of DCA with water (molar ratio of water/DCA = 1,1). The flow rate of the injection mixture is 11 g/hour.

At the exit of the reactor vapors are condensed in a glass trap at room temperature.

The final reaction mixture was analyzed by chromatography in the gaseous phase. Determine the degree of transformation (TT) amino-kapronasia, output (RT) caprolactam (CPL) in relation to developed aminoacetonitrile.

Using different methods of analysis (chromatography in gas phase in combination with mass spectrometry, particularly nuclear magnetic resonance) state the complete disappearance of side products in the form of amines and Iminov present in the used aminoacetonitrile.

Get these stable characteristics for the duration of the reaction 7 hours: TT AKN = 63%,

RT KPL = 100%.

1. The method of producing lactam hydrolysis by cyclization of aminonitriles obtained by the use of hydrogen and in the presence of a catalyst, the resulting aminonitriles distilled to the content of dinitrile less than or equal to 10 wt.% and by-products with imino - or aminopentyl less than or equal to 10 wt.%, then distilled aminonitriles subjected to hydrolysis in the vapor phase by cyclization in the presence of water and possibly of the catalyst.

2. The method according to p. 2, characterized in that used in the first stage aliphatic dinitrile choose among dinitriles General formula I

NC-R-CN,

in which R denotes alkylenes or alkenylamine, linear or branched group with 1 to 12 carbon atoms and preferably 1 to 6 carbon atoms.

3. The method according to any of paragraphs.1 and 2, characterized in that providerone of dinitrile to the appropriate aminonitriles carried out in the presence of a catalyst based on Raney Nickel, Raney cobalt and Raney Nickel or Raney cobalt containing an activating element selected among the group members IV, VI, VII and VIII of the Periodic system of elements, and a strong inorganic bases, derived from alkali or alkaline earth metal.

4. The method according to p. 3, wherein the used catalyst, in which a strong inorganic base is chosen among hydroof, carbonates and alkanoates alkali metal.

5. The method according to p. 3, characterized in that the amount used of the catalyst is 0.5 - 50 wt.% catalyst based on the total weight of the reaction medium, preferably 1 to 35%.

6. The method according to any of paragraphs.1 to 5, characterized in that the stage of providerone the reaction is carried out at a temperature below or equal to 150°C., preferably lower than or equal to 120°C. and more preferably lower than or equal to 100°C.

7. The method according to any of paragraphs.1 - 6, characterized in that the stage of providerone carried out at a hydrogen pressure in the range of 1 bar (0,10 MPa) - 100 bar (10 MPa), preferably 5 bar (0.5 MPa) 50 bar (5 MPa).

8. The method according to any of paragraphs.1 to 7, characterized in that the front of the stage hydrolysis by cyclization of aminonitriles after providerone clear of a large part of the water and/or solvent, unreacted dinitrile, and from the resulting diamine and side reaction products by conventional surgery distillation is preferably carried out at a pressure below atmospheric, to content dinitrile to 10 wt.%, preferably up to 5 wt.%, and other by-products up to 10 wt.%, preferably up to 5 wt.%, in aminonitriles Plaut by reacting in the vapor phase of aliphatic aminonitriles General formula II

N C-R-CH2-NH2,

in which R denotes alkalinity or alkenylamine, linear or branched radical with 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, with water, preferably in the presence of the solid catalyst.

10. The method according to p. 9, characterized in that the solid catalyst using molecular sieves, such as acidic zeolite or silicalite, neoreality molecular sieves, metal phosphate or solid oxides acidic or amphoteric character.

11. The method according to p. 10, characterized in that the metal phosphate is used as a compound of General formula III

(RHO4)nHpM(lmp)p,

in which M denotes a divalent, trivalent, tetravalent or pentavalent element, selectable in groups 2A, 3b, 4B, 5B, 6b, 7b, 8, 2B, 3A, 4A and 5A of the Periodic system of elements, or a mixture of several of these elements; or M = 0, where M denotes some pentavalent elements;

lmp indicates impregnating the connection of the main character, formed of alkali or alkaline earth metal, or mixtures of several of these metals are United with protivoiona to ensure electroneutrality;

n is the compared between the impregnating compound lmp and imprintirovannymi connection (RHO4)nHpM

12. The method according to p. 10, wherein the solid oxide is aluminum oxide.

13. The method according to p. 12, characterized in that use activated alumina with a specific surface area of 5 to 200 m2/g, preferably 10 to 500 m2/,

14. The method according to any of paragraphs.1 and 9 to 13, characterized in that the molar ratio between the supplied water and aminonitriles is 0.5 to 50, preferably 1 to 20 and more preferably 2 to 20.

15. The method according to any of paragraphs.1 and 9 to 14, characterized in that the temperature at which phase hydrolysis with cyclization is 200 - 450°C, preferably 250 to 400°C.

 

Same patents:
The invention relates to the production of caprolactam, which is used to produce polymeric products

The invention relates to the production of aliphatic lactams, in particular E-caprolactam used in the production of polyamides

The invention relates to the production of modified layered silicates and can be used in the manufacture of paints, coating of enamel, plaster, household paints, ceramic industry for obtaining anhydrous molding compounds, as active fillers in polymers and rubbers, for lubricating and cooling fluids, drilling fluids oil-based

-alkoxyalkyl)caprolactam with protecting and aerorepublica activity" target="_blank">

The invention relates to new biologically active compounds, namely N-(-alkoxyalkyl)caprolactam General formula

NH - OC6H13where R is H, CH3with insect - and aerorepublica activity

-alkoxyalkyl)caprolactam with insectrepellent activity" target="_blank">

The invention relates to new biologically active compounds, namely N-(-alkoxyalkyl)caprolactam General formula

NH - OR1where R=C3H7when R1=C2H5-C4H9with insectrepellent activity

The invention relates to a method for continuous purification of crude caprolactam obtained by the interaction of 6-aminocaproate with water
The invention relates to the production of caprolactam, which is used to produce polymeric products

The invention relates to the production of aliphatic lactams, in particular E-caprolactam used in the production of polyamides

The invention relates to a new process for the preparation of cyclic lactams by reacting NITRILES aminocarbonyl acid with water in the presence of catalysts

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for preparing caprolactam by the cyclization reaction of derivatives of aminocaproic acid. Method is carried out by cyclizing hydrolysis of compound chosen from the group comprising aminocaproic acid esters or amides, or their mixtures. The process is carried out in the presence of water, in vapor phase at temperature 200-450°C in the presence of a solid catalyst comprising of aluminum oxide that comprises at least one macroporosity with pores volume corresponding to pores with diameter above 500 Å taken in the concentration 5 ml/100 g of above. Preferably, the specific square of catalyst particles is above 10 m2/g and the total volume of pores is 10 ml/100 g or above wherein pores volume corresponds to pores with diameter above 500 Å is 10 ml/100 g or above. Invention provides improving the process indices due to the improved properties of the solid catalyst.

EFFECT: improved preparing method.

5 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of caprolactam from alkylcyanovalerate which involves bringing alkylcyanovalerate into contact with hydrogen in gaseous state in the presence of a hydrogenation catalyst and a ring formation catalyst, and treatment after condensation of a gaseous stream containing the formed lactam in order to separate ammonium which may be present, the formed alcohol and/or the caprolactam solvent and extraction of caprolactam, where the hydrogenation catalyst includes a metal element or a mixture of metal elements selected from a group containing an active metal element in form of iron, ruthenium, rhodium, iridium, palladium, cobalt, nickel, chromium, osmium and platinum or several metals from this list, and the ring formation catalyst is porous aluminium oxide.

EFFECT: obtaining caprolactam without intermediate separation of alkylaminocaproate.

10 cl, 5 ex, 1 tbl

FIELD: chemistry of lactams' derivatives.

SUBSTANCE: the present innovation deals with obtaining N-(2-chloroalkyl)- and N-alkyl-aromatic derivatives of lactams of the following general formula: , where R=H, Cl, R'=(CH2)3, (CH2)5 which could be modifiers of unsaturated carbon-chain caoutchoucs and rubber mixtures based upon them. The suggested method for obtaining the mentioned N-substituted lactams deals with combining N-chlorolactams and allyl benzene, moreover, as N-lactams one should apply either N-chlorobutyrolactam or N-chlorocaprolactam. The process should be carried out at molar ratio of N-chlorolactam to allyl benzene being equal to 1-1.15:1, at availability of a catalyzer as mono-tertiary-butylperoxy-α-methylmethoxyethoxyethyl ether of ethylene glycol taken at the quantity of 0.4-4.0% weight, in the medium of inert solvent, for example, chlorobenzene at 100-125° C for about 15-20 min. The innovation enables to shorten terms of reaction by 20-30 times, simplify the way for obtaining target products and widen the assortment of the obtained compounds, as well.

EFFECT: higher efficiency.

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for preparing caprolactam by the cyclization reaction of derivatives of aminocaproic acid. Method is carried out by cyclizing hydrolysis of compound chosen from the group comprising aminocaproic acid esters or amides, or their mixtures. The process is carried out in the presence of water, in vapor phase at temperature 200-450°C in the presence of a solid catalyst comprising of aluminum oxide that comprises at least one macroporosity with pores volume corresponding to pores with diameter above 500 Å taken in the concentration 5 ml/100 g of above. Preferably, the specific square of catalyst particles is above 10 m2/g and the total volume of pores is 10 ml/100 g or above wherein pores volume corresponds to pores with diameter above 500 Å is 10 ml/100 g or above. Invention provides improving the process indices due to the improved properties of the solid catalyst.

EFFECT: improved preparing method.

5 cl, 2 ex

Up!