RU2258562C2 - Molded ionite catalyst and a method for preparation thereof - Google Patents

Abstract

FIELD: organic synthesis catalysts.

SUBSTANCE: invention relates to methods of preparing catalysts based on sulfurized styrene/divinylbenzene copolymer and thermoplastic polymer material, which are used in processes for preparing alkyl tert-alkyl ethers, hydration of olefins, dehydration of alcohols, preparation of esters, and the like. Invention provides molded ionite catalyst consisted of sulfurized styrene/divinylbenzene copolymer in the form of mixture of powdered copolymers with macroporous and gel structure and, as thermoplastic material, propylene polymers and propylene/ethylene copolymers. Preparation of catalyst is accomplished by extrusion at temperature of heating extruder cylinder 140-200°C and temperature of forming head equal to temperature of the last heated zone of heating cylinder.

EFFECT: increased catalytic activity.

10 cl, 3 tbl, 15 ex

Description

The invention relates to methods for the preparation of catalysts, in particular catalysts based on a sulfonated copolymer of styrene and divinylbenzene and a thermoplastic polymer material. These catalysts are widely used in the processes of producing alkyl tert-alkyl esters, hydration of olefins, dehydration of alcohols, production of esters, etc.

A known catalyst and method for its preparation based on ion-exchange resins and thermoplastic polymeric materials by mixing them, heating to the melting temperature of the thermoplastic and molding the finished product by extrusion (USSR Author's Certificate N 376984, class 01 J 11/00, 1970). The catalyst prepared in this way has a low activity. In addition, when swelling in water, an increase in the volume of the catalyst by two to three times and a decrease in its mechanical strength are observed.

A known catalyst and method for its preparation on the basis of ion-exchange resins and thermoplastic polymeric materials with the addition of an organic substance capable of combining with thermoplastics and dissolving in organic solvents (USSR Author's Certificate N 448664, class B 01 J 11/00, 1971). The disadvantage of this method is the introduction of an additional stage in the process of its preparation - treatment with an organic solvent.

The closest analogue is an ion-based catalyst based on a sulfonated styrene-divinylbenzene copolymer and a method for its preparation, comprising mixing a sulfonated styrene-divinylbenzene copolymer with a thermoplastic polymer material and water, heating the mixture to the melting temperature of the thermoplastic and molding the mixture by extrusion (USSR Author's Certificate No. 677191, C. B 01 J 37/00, B 01 J 31/08, 1972). At the molding stage, the temperature of the material cylinder is set to 20-40 ° C lower than the temperature of the forming head.

However, the catalyst obtained by this method has a relatively low activity in the processes of hydration of isobutene (IB) to trimethylcarbinol (TMK), dehydration of TMK to IB, and also in the synthesis of methyl tert-butyl ether (MTBE). So, the values of the specific productivity of the catalyst calculated from the examples of the method description in the process of TMC dehydration (example 5) do not exceed 0.021 mol of the product / (g cat · hour), in the process of hydration of IB (example 7) 0.01 mol of the product / (g cat · hour), in the synthesis of MTBE (example 8), 0.026 mol of MTBE / (g cat · hour).

The aim of the present invention is to obtain a catalyst with increased activity.

This goal is achieved by using an ion-exchange molded catalyst consisting of a sulfonated copolymer of styrene and divinylbenzene and a thermoplastic material - polymers of propylene or copolymers of propylene and ethylene, in which a mixture of powdered sulfonated copolymers of styrene and divinylbenzene with macroporium is taken as a sulfonated copolymer of styrene and divinylbenzene. In this case, the preparation of this catalyst is carried out by mixing sulfonated copolymers of styrene and divinylbenzene and a thermoplastic material, followed by molding the resulting mixture by extrusion, which is carried out at an extruder material cylinder temperature of 140-200 ° C and a forming head temperature equal to the temperature in the last heated zone of the extruder material cylinder.

Preferably, as a sulfonated styrene-divinylbenzene copolymer, a mixture of powdered sulfonated styrene-divinylbenzene copolymers of a macroporous and gel structure is taken with a mass ratio of (1 ÷ 9): (9 ÷ 1) based on the dry weight of the copolymers.

Preferably, as a sulfonated styrene-divinylbenzene copolymer, a mixture of powdered sulfonated styrene-divinylbenzene copolymers of a macroporous and gel structure with a water content of 5-25% wt.

Preferably, fractions containing not more than 15 wt.% Are used as the sulfonated copolymer of styrene and divinylbenzene with macroporous and gel structures. particles of copolymers in terms of dry product with a size of more than 125 microns.

Preferably, fractions containing not less than 75 wt.% Are used as the sulfonated copolymer of styrene and divinylbenzene gel structure. particles of the copolymer in terms of dry product with a size of less than 100 microns.

Preferably, fractions containing not less than 50 wt.% Are used as the sulfonated copolymer of styrene and divinylbenzene of the macroporous structure. particles of the copolymer in terms of dry product with a size of less than 100 microns.

Preferably, fractions containing at least 99% by weight are used as the sulfonated copolymer of styrene and divinylbenzene of the macroporous structure. particles of the copolymer in terms of dry product with a size of less than 200 microns.

Preferably, propylene polymers or copolymers of propylene and ethylene are used as the thermoplastic material.

Preferably, the mixture is formed in an extruder having more than two heated zones.

Preferably, the temperature in each subsequent heated zone of the extruder is maintained at 5-15 ° C. higher than the temperature of the previous heated zone.

As the sulfonated copolymers of styrene and divinylbenzene, powdered gel and macroporous sulfocationites according to TU 2227-025-39659962-2003 can be used, as well as, in particular, sulfocationites according to GOST 20298-74 and TU95.981-93, crushed and dried to the above parameters.

As thermoplastic materials, polypropylene according to TU 2211-075-54155590-01 of grades 21007 and 21015 and a copolymer of propylene with ethylene of grades 23007 and 23015 can be used.

The following examples illustrate the method:

Preparation of the catalyst.

Example 1

In a drum-mixer with a volume of 1.5 m ³ through a special hatch load 37.5 kg of powdered polypropylene grade 21007, 15.0 kg of powdered macroporous sulfocationionite containing 25% wt. water, and 117.6 kg of powdered gel sulfocationite containing 14% wt. water. The mass ratio of powdered sulfocationic macroporous and gel structure is 1: 9 by dry weight. The content of sulfocathionites on dry weight in a mixture with polypropylene is 75% wt. in terms of dry weight.

The mass fraction of the fraction above 125 microns of powdered macroporous sulfocationionite is 15.0%, gel - 8.0%. The mass fraction of the fraction below 100 microns of powdered macroporous sulfocationionite is 58.0%, gel - 83.0%. The mass fraction of the fraction below 200 microns of powdered macroporous sulfocationionite is 99.2%.

After loading the components, the manhole cover is closed, the electric drive is turned on, and polypropylene and sulfocationionites are thoroughly mixed by rotating the mixer drum at a speed of 120 rpm for 4 hours. At the end of mixing, the mixture is unloaded through the open hatch from the mixer drum into the metering hopper, from where it is dosed with a screw into the CHOP-85 worm-squeezer press.

In a worm-squeezing press, with the help of two worm shafts of different lengths rotating towards each other, a mixture of sulfocationites with polypropylene is fed through four consecutively located and heated zones to the granulating head. The temperature in the housing of the first heated zone is supported by 155 ° C, the second by 170 ° C, the third by 185 ° C, the fourth and the granulating head by 200 ° C.

Having passed all the zones of the worm-squeezing machine, the catalyst mass is pressed through the die and comes out in the form of cylinders or tubes, depending on the design of the forming head. Outgoing cylinders or tubes are cut with a rotating knife to obtain granules of a certain length, which is controlled by the number of revolutions of the rotating knife. The catalyst granules are cooled with water to prevent sticking, washed off on a vibrating screen and loaded into 20 kg bags.

Examples 2-7.

Illustrate the method of preparation of the catalyst under other conditions: mass ratios of MPI / GI of sulfocathionites, the content of sulfocationionites in a mixture with thermoplastic material, the sizes of the used fractions of sulfocationionite particles, grades of thermoplastic material, the temperature of the heated zones and the number of heated zones.

The conditions for the preparation of catalysts are shown in table 1.

Testing of catalyst samples in the synthesis of methyl tert-butyl alcohol, isobutene hydration, and trimethylcarbinol dehydration.

Example 8

Synthesis of methyl tert-butyl ether (MTBE) is carried out in a continuous facility using an ionized molded catalyst obtained in experiment 3. 30 g of catalyst are charged into a tubular reactor with an inner diameter of 21 mm and a length of 1 m, equipped with a thermostatic jacket. Methanol with a basic substance content of 99.95% wt. continuously at a speed of 280 ml / hour (221.5 g / hour, 6.92 mol / hour) served in the line of isobutylene with a basic substance content of 99.9% wt. The feed rate of isobutylene is 320 ml / hour (191.0 g / hour, 3.41 mol / hour). The molar ratio of methanol: isobutylene in the initial mixture at the inlet to the reactor is 2: 1. The temperature in the reactor is maintained at 90 ° C by supplying a coolant from the thermostat to the jacket, pressure 2.0 MPa. Leaving the reactor, the reaction mass contains,% wt .: MTBE 66.76; methanol 29.38; isobutylene 3.71; trimethylcarbinol (TMK) 0.15. The degree of conversion of isobutylene 92%. The productivity of the catalyst is 0.104 mol MTBE / (g cat · hour) compared with 0.026 mol MTBE / (g cat · hour) in the prototype.

Example 9

The synthesis of MTBE is carried out using the catalyst obtained in example 5, according to the technology described in example 8. Methanol with a basic substance content of 99.95% wt. continuously at a speed of 135 ml / hour (107 g / hour, 3.34 mol / hour) fed into the line of the isobutane-isobutylene fraction with an isobutylene content of 45% wt. The feed rate of the isobutane-isobutylene fraction is 365 ml / hour (299.5 g / hour, 1.68 mol / hour of isobutylene). The molar ratio of methanol: isobutylene in the initial mixture at the inlet to the reactor is 2: 1. The temperature in the reactor is maintained at 90 ° C and a pressure of 2.0 MPa. Leaving the reactor, the reaction mass contains,% wt .: MTBE 42.95; methanol 18.17; isobutylene 2.40; isobutane 36.40; trimethylcarbinol 0.08. The degree of conversion of isobutylene 92%. The productivity of the catalyst is 0.051 mol of MTBE / g cat · hour compared to 0.026 g of MTBE / g cat · hour in the prototype using 100% isobutylene.

Example 10

Hydration of isobutylene is carried out in a continuous installation using an ionized molded catalyst obtained in experiment 2. 30 g of catalyst are charged into a tubular reactor with an inner diameter of 21 mm and a length of 1 m, equipped with a thermostatic jacket. In the lower part of the reactor isobutylene is continuously fed with a basic substance content of 99.95% by weight. at a rate of 40 ml / hour (23.9 g / hour, 0.43 mol / hour), water at a rate of 280 ml / hour (280 g / hour, 15.54 mol / hour) to the upper part. The volumetric ratio of water: isobutylene 7: 1. The temperature in the reactor is maintained at 90 ° C by supplying a coolant from the thermostat to the jacket, pressure 2.0 MPa. From the bottom of the reactor comes the reaction mass of the following composition,% wt .: TMK 10.05; water 89.69; isobutylene 0.24; isobutylene dimers 0.02. The degree of conversion of isobutylene 97%, the selectivity of 99.74. The productivity of the catalyst is 0.014 mol TMK / (g cat · hour) compared with 0.0103 mol TMK / (g cat. · Hour) in the prototype.

Examples 11-14.

Illustrate the activity of the catalysts obtained in examples 1, 4, 6 and 7. The results are shown in table 2.

Example 15

Trimethylcarbinol dehydration is carried out in a batch unit using molded ionite catalysts obtained in experiments 1-7. In a glass flask with a capacity of 500 cm ³ equipped with a reflux condenser, 10 ± 0.1 g of dried at a temperature of 100-105 ° C are placed to a constant mass of the catalyst and 50 cm ^{3 of} trimethylcarbinol are poured with a cylinder. The dehydration process is carried out at the boiling temperature of TMK (80 ° C), which is maintained using a boiling water bath.

The isobutylene released during the decomposition of TMK is condensed in a graduated ampoule cooled in a Dewar vessel filled with a mixture of acetone and solid carbon dioxide. Every 30 minutes, the volume of isobutylene obtained is recorded. At the end of the experiment (after 2 hours), the temperature of the cooling mixture is measured to accurately determine the mass of isobutylene accumulated in the ampoule.

The activity of the catalyst is determined in percent as the ratio of the mass of isobutylene released to the theoretically possible. The results are shown in table 3.

Table 3
Tests of catalyst samples in the process of trimethylcarbinol dehydration. Catalyst Isobutylene volume measurement time, hour Activity,% The performance of the catalyst, mol / (g cat · h) According to example 1 1,5 75 0.0264 According to example 2 1,5 81 0.0285 For example 3 1.0 80 0.0422 For example 4 1,5 78 0,0274 For example 5 1,0 76 0,0401 For example 6 2.0 79 0,0208 For example 7 2.0 81 0.0214

The use of the proposed ionized molded catalyst and the method for its preparation allows to increase the productivity of processes for the production of alkyl tert-alkyl ethers, hydration of olefins, dehydration of alcohols, production of esters, etc., to increase the degree of conversion of the starting reagents and, as a result, to reduce energy costs.

Claims (10)

1. Ionite molded catalyst, consisting of a sulfonated copolymer of styrene and divinylbenzene and a thermoplastic material - polymers of propylene or copolymers of propylene and ethylene, characterized in that a mixture of powdered sulfonated copolymers of styrene and divinylbenzene with macroporon structure is used as a sulfonated copolymer of styrene and divinylbenzene. 2. The method of producing the ionized molded catalyst according to claim 1 by mixing a sulfonated copolymer of styrene and divinylbenzene and a thermoplastic material and molding the resulting mixture by extrusion at elevated temperatures of the material cylinder of the extruder and the forming head, characterized in that the mixture is molded at a temperature of the material cylinder of the extruder 140 -200 ° C and the temperature of the forming head equal to the temperature in the last heated zone of the material cylinder of the extruder. 3. Ionized molded catalyst according to claim 1, characterized in that as a sulfonated copolymer of styrene and divinylbenzene, a mixture of powdered sulfonated copolymers of styrene and divinylbenzene with a macroporous and gel structure is used at a mass ratio of (1 ÷ 9): (9 ÷ 1) based on dry weight of copolymers. 4. The ionized shaped catalyst according to claim 1, characterized in that a mixture of powdered sulfonated styrene-divinylbenzene copolymers of macroporous and gel structure with a water content of 5-25 wt.% Is used as a sulfonated styrene-divinylbenzene copolymer. 5. The molded catalyst according to claim 1, characterized in that fractions containing not more than 15 wt.% Of the particles of the copolymers in terms of a dry product with a size greater than 125 μm are used as a sulfonated styrene-divinylbenzene copolymer of a macroporous and gel structure. 6. Ionite molded catalyst according to claim 1, characterized in that fractions containing at least 75 wt.% Of the copolymer particles in terms of a dry product with a size of less than 100 μm are used as a sulfonated styrene-divinylbenzene gel gel structure. 7. Ionite molded catalyst according to claim 1, characterized in that fractions containing at least 50 wt.% Of the copolymer particles in terms of dry product with a size of less than 100 μm are used as a sulfonated styrene-divinylbenzene macroporous copolymer. 8. The molded catalyst according to claim 1, characterized in that fractions containing not less than 99 wt.% Of the copolymer particles in terms of a dry product with a size of less than 200 μm are used as a sulfonated styrene-divinylbenzene copolymer of a macroporous structure. 9. The method according to claim 2, characterized in that the mixture is formed in an extruder having more than two heated zones. 10. The method according to claim 2, characterized in that the temperature in each subsequent heated zone of the extruder is maintained at 5-15 ° C higher than the temperature of the previous heated zone.