JPS6216437A - Production of olefin rich in ethylene - Google Patents

Abstract

PURPOSE:To obtain the titled compound from methanol or dimethyl ether, by using a catalyst prepared by firing a crystalline aluminosiliate at a high temperature or exchanging alkali metal ions wholly or partially with multivalent metal ions, e.g. zinc or lanthanum. CONSTITUTION:A lower olefin rich in ethylene is produced from methanol or dimentyl ether as a raw material. In the process, a calayst obtained by firing a crystalline aluminosilicate of erionite/offretite based zeolite prepared by the presence of a seed solid material in an aqueous raw material mixture containing a silica source, alumina source, alkali metal salt and a choline compound or exchanging at least part of alkali metal ions with multivalent metal ions, e.g. zinc or lanthanum, is used as a catalyst, and regenerated for reuse by burning and removing periodically carbonaceous materials deposited on the catalyst.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing ethylene-rich lower olefins from methanol and/or dimethyl ether using crystalline aluminosilicate obtained by a new production method as a catalyst. It is.

In particular, the present invention uses as a catalyst a crystalline aluminosilicate which has been calcined at a high temperature to exchange all or part of the alkali metal ions with polyvalent metal ions such as zinc or lanthanum. This invention relates to a method for producing ethylene-rich lower olefins by periodically burning off carbonaceous materials deposited on top.

[Prior Art] Many natural and synthesized crystalline aluminosilicates such as zeolites are known. These crystalline aluminosilicates have pores forming a large number of three-dimensional structures and are used as molecular seeds for adsorbents and gas separation, and are also used industrially as catalysts for conversion of hydrocarbons.

Recently, many methods have been developed for producing lower olefins from methanol or dimethyl ether using various crystalline aluminosilicates as catalysts. For example, ZSM-5 zeolite manufactured by Mopil Oil Co., Ltd. is used to produce lower olefins from dimetatool by modifying with silane, manganese, calcium, etc., and ZSM-34 zeolite (Japanese Patent Application Laid-open No. 58499-1989) is used to produce lower olefins from methanol. Used to produce olefins.

[Problem that the invention seeks to solve]

However, although the ZSM-5 zeolite has a large pore size and is suitable for gasoline production, it has low selectivity for lower olefins, making it unsuitable for producing lower olefins.
Furthermore, although ZSM-34 zeolite exhibits high selectivity as a catalyst for producing ethylene, propylene, etc. from methanol, its activity deteriorates extremely quickly due to carbon deposits on the catalyst, and the deteriorated catalyst cannot be exposed to air, hydrogen, etc. Even with regeneration treatment, this deterioration could not be completely removed, and it could not be said that this type of catalyst was necessarily satisfactory.

[Failure to solve the problem]

The present inventors have conducted various studies to develop a method for efficiently producing ethylene-rich lower olefins using methanol and dimethyl ether as raw materials.
A crystalline aluminosilicate of erionite noophretite zeolite obtained by the presence of a seed solid in an aqueous raw material mixture containing an alumina source, an alkali metal salt, and a choline compound is calcined at high temperature or its alkali metal ions are By exchanging at least a portion of ethylene with polyvalent metal ions such as zinc or lanthanum and using it as a catalyst, it is possible to efficiently produce the desired ethylene-rich lower olefin, and further, during this process, the ethylene-rich olefin is precipitated on the catalyst. The present inventors have discovered that it is possible to stably produce lower olefins rich in ethylene by periodically burning and removing the carbonaceous materials, and have completed the present invention.

An object of the present invention is to provide a method for producing lower olefins rich in ethylene, which can efficiently and stably produce lower olefins such as ethylene, propylene, butene, which are key raw materials for petrochemistry, from methanol or dimethyl ether. It is in. That is, the present invention produces a solid material containing crystalline aluminosilicate by holding an aqueous raw material mixture containing a silica source, an alumina source, an alkali metal salt, and a choline compound under hydrothermal synthesis conditions in which the choline compound does not vaporize or decompose. A part of the solid material containing crystalline aluminosilicate obtained in the seed solid synthesis step is used as a seed, and an aqueous raw material mixture containing this, a silica source, an alumina source, an alkali metal salt, and a choline compound is mixed until the choline compound is vaporized or Aluminosilicate obtained by holding under hydrothermal synthesis conditions that do not decompose is calcined at a high temperature to convert at least a part of it into the H (proton) form, or at least a part of the alkali metal is converted into polyvalent metal ions. This is a method for producing ethylene-rich olefins, which is characterized by using an exchanged olefin as a catalyst and contacting it with methanol and/or dimethyl ether at high temperature and under normal pressure to extremely high pressure.

Next, the method for producing the crystalline aluminosilicate catalyst used in the present invention will be described in detail. As a silica source, silica powder, silicic acid, colloidal silica, dissolved silica, etc. are used, and as an alumina source, aluminum sulfate, nitrate, etc., nylium aluminate, colloidal alumina, alumina, etc. are used, and alkali metal Hydroxides such as sodium, potassium, and rubidium are used as salts, and choline compounds such as choline, choline chloride, and choline hydroxide are used as organic additives.

In the seed solid synthesis step, the mother liquor gel raw material as described above is used and the choline compound is not vaporized or decomposed under hydrothermal synthesis conditions, that is, the aqueous raw material mixture consisting of the silica source, alumina source, alkali metal salt, and choline compound is heated at 50°C to 1
A solid containing crystalline aluminosilicate is produced by holding at 70°C for 1 to 12 days. The solid obtained in this case is a low-crystalline aluminosilicate having erionite and oletite with low crystallinity. A part of the solid material containing this crystalline aluminosilicate is used as a seed in the next step, and it may be in the form of a mother liquor gel, dried product, or fired product.

Next, a part of the solid material containing the crystalline aluminosilicate thus obtained is used as a seed, and an aqueous mixture containing this and the above-mentioned silica source, alumina source, alkali metal salt, and choline compound is prepared. Highly crystalline aluminosilicates of erionite and offretite zeolites are obtained by maintaining the zeolites under the same hydrothermal synthesis conditions as described above.

That is, a highly crystalline aluminosilicate can be obtained by using a solid material containing low crystalline aluminosilicate as a seed. Further, the highly crystalline aluminosilicate obtained by hydrothermal synthesis in this manner can be used as a seed. In any process, an amount of about 0.01 to 3% by weight of the aqueous raw material mixture based on the olide is sufficient.

If the amount of rice crystals is too small, a product with high purity cannot be obtained, and if there are too many rice crystals, the yield will be lowered, which is undesirable. The crystalline aluminosilicate thus obtained is used as a catalyst in the method of the present invention, but it is preferable that at least a part of the exchangeable cations of the crystalline aluminosilicate are hydrogen ions (proton type). It is preferable.

On the other hand, if the amount of hydrogen ion exchange is too large, the hydrogen transfer reaction becomes noticeable in the methanol conversion reaction, the selectivity for lower olefins is significantly reduced, and furthermore, carbon precipitation is promoted and catalyst deterioration is accelerated. Therefore, in the present invention, a hydrogen ion exchange amount in the range of several tens of inches is desirable.

This crystalline aluminosilicate contains nitrogen compound ions in addition to alkali metal ions as part of the cations in its crystals, so in order to convert nitrogen compound ions to hydrogen ions, the crystalline aluminosilicate must be passed through air circulation. Lower, 400-800℃, preferably 500-600℃
Further, the crystalline aluminosilicate is produced as a powder, but when used as a catalyst, it may be molded into an appropriate shape. This molding may be carried out by a conventional method, such as extrusion molding, tablet molding, spray drying granulation, or the like. At that time, a binder or a molding aid that is normally added can be added.

For example, silica, alumina, silica, alumina, clays, graphite, stearic acid, starch, polyvinyl alcohol, etc. can be added in an amount of 80% or less, preferably in the range of 2 to 40%. The molded product thus obtained is fired and used as a catalyst in the present invention.

In addition to the above-mentioned catalysts, the catalyst used in the present invention preferably exchanges all or part of the alkali metal ions of the crystalline aluminosilicate with polyvalent ions such as zinc or lanthanum.

This exchange may be carried out by a known method. For example, the crystalline aluminosilicate formed into the molded product is ion-exchanged in an aqueous solution containing ammonium ions, such as a monovalent ammonium nitrate aqueous solution, to convert it into an ammonium type, and then zinc nitrate or lanthanum nitrate is used. All or part of the dialkali metal ions may be exchanged with polyvalent ions such as zinc or lanthanum by ion exchange again in an aqueous solution of . This ion exchange may be performed before making the crystalline aluminosilicate into a molded product.

The process of the invention is carried out by contacting methanol and/or dimethyl ether with the crystalline aluminosilicate catalyst at elevated temperatures.

The reaction method may be fixed bed, fluidized bed or moving bed, and the shape of the catalyst can be selected accordingly. The reaction temperature is 300 to 500°C, preferably 350 to 400°C, and the pressure is not particularly limited, but is usually in the range of 1 to 30 atm, preferably 1 to 20 atm.

The raw materials methanol and/or dimethyl ether may be fed onto the catalyst as they are, or may be fed directly onto the catalyst using water, nitrogen, helium, carbon dioxide, hydrogen, argon, etc. or methane, ethane,
An inert carrier gas or diluent can be added at the same time to the conversion reaction of pro-zone, etc., and the addition of water is particularly preferred. At this time, it is desirable that the concentration of methanol and/or dimethyl ether in the raw material is 10 or more. Furthermore, 1cLH3V (liquid hourly space velocity) is 0.01~
30 hr-'', preferably in the range of 0.1 to IQhr.

As a reaction method, methanol may be dehydrated using a known catalyst such as r-alumina and converted into dimethyl ether, and then passed over the aluminosilicate catalyst. Of course,
Unreacted methanol and/or recovered in this conversion reaction
Alternatively, there is no problem in recycling dimethyl ether as a raw material again.

In the method of the present invention, part or all of the catalyst whose activity has decreased over time is periodically circulated in a normal manner, that is, at a high temperature of 400 to 800°C containing oxygen such as air, to precipitate it on the catalyst. By burning off the carbonaceous material, it becomes possible to regenerate and reuse it.

The present invention will be explained below with reference to Examples, but it is not limited to these Examples.

In the examples, all reactions were carried out under normal pressure using a fixed bed flow microreactor (10 x 200 m).

Example 1 Sodium aluminate (special grade Mα atomic ratio 0°78, manufactured by Wako Tsugyaku Kogyo) 26.76.9. Sodium hydroxide (special grade manufactured by Wako Tsumugi Pharmaceutical Industries) 11.9511 and potassium hydroxide (special grade manufactured by Wako Tsumugi Pharmaceutical Industries) 13.01! i = 266.14g of water
dissolved in. To this solution, add chlorinated purine (special grade manufactured by Tokyo Chemical Industry Co., Ltd.) 112.37 F, and then add silica sol solution (Snowtex 30 manufactured by Nichikagaku Kogyo Co., Ltd.) 384.4
3N was added and mixed to prepare a mother liquid gel.

This mother liquor gel was placed in a Pyrex autoclave and maintained under self-generated pressure at 150° C. for 8 days to convert it into zeolite. After the reaction was completed, the product was filtered and washed three times with 11 portions of distilled water each time. Then 120℃
After drying, the product was calcined in an air stream at 550° C. for 3 hours, thereby obtaining a crystalline product (A).

Powder X-ray diffraction results of this product show low erionite/o7
It was a retite-based zeolite.

Next, the above crystalline product (A) 311 was added and mixed to the mother liquor gel obtained in exactly the same manner as above, and the same was set in a Pyrex autoclave and zeolite formation was carried out at 150°C under self-generated pressure. The reaction stopped within days. Thereafter, crystal formation (total) was obtained in the same manner.

X-ray diffraction of this powder revealed that it was an erionite/offretite zeolite with very high crystallinity.

35% by weight of alumina binder was added to this powder to form a molded product, which was dried again and then calcined in an air stream at 550° C. for 3 hours to obtain a catalyst.

This catalyst 5d was filled in an atmospheric pressure flow reactor, and the methanol conversion reaction was continued for 4 hours at LH8V I Aτ and a reaction temperature of 350° C. using raw materials to which water had been added so that the methanol concentration was 30% by weight.

Table 1 shows the reaction results up to 4 hours from the start of the reaction.

Example 2 Catalyst II produced in Example 1 was made into a sheath-supported ammonium type by subjecting it to natural reflux for 2 hours in 5 d of a 2.2N ammonium nitrate aqueous solution and repeating the process four times. Thereafter, it was dried and left to stand at 88° C. for 4 hours in a 1N aqueous solution of zinc nitrate, thereby ion-exchanging it into a zinc type.

This catalyst was dried and then calcined to carry out the same reaction as in Example 1. The results are shown in Table-1.

Example 3 The same operation as in Example 2 was carried out except that zinc nitrate in Example 2 was changed to lanthanum nitrate, and the reaction results are shown in Table 1.

Examples 4 to 7 The spent catalyst of Example 1 was blown with air for 20 minutes at 550°C.
wIL/TrLix was introduced and calcination was continued until no carbon dioxide was observed in the gas exiting the reaction tube.

Next, after sufficiently purging oxygen with nitrogen gas, a reaction was carried out under the same conditions as in Example 1, and then the same operation was repeated three times.

The results of these reactions are shown in Table-1.

Comparative Example 1 Sodium aluminate (special grade A4/Nα atomic ratio 0.78, made by Wako Tsumugi Kogyo) 26.76 J, sodium hydroxide (special grade made by Wako Tsumugi Kogyo) 11.95 II, and potassium hydroxide (wako Tsumugi Kogyo Kogyo) (special grade) 13.01g in water 26
6.1411. To this solution was added 112.37 g of choline chloride (special grade manufactured by Tokyo Chemical Industry Co., Ltd.), and then a silica sol solution (Snowtex 30 manufactured by Yasan Kagaku Kogyo Co., Ltd.) 3
84.43II'' was added and mixed to prepare a mother liquor gel.

This mother liquor gel was placed in an autoclave manufactured by Nozo Irex and maintained at 150° C. under self-generated pressure for 8 days to convert it into zeolite. After the reaction was completed, the product was filtered and washed three times with 11 portions of distilled water each time. then 12
After drying at 0° C., it was calcined at 550° C. for 3 hours in a stream of air, thereby obtaining a crystalline product (Al).

As a result of powder X-ray diffraction of this product, it was found to be a low erionite/offretite zeolite.

This crystalline aluminosilicate was catalyzed and reacted in the same manner as in Example 1. The results are shown in Table-2.

Comparative Example 2 Highly crystalline aluminosilicate was obtained by performing the same operation as in Comparative Example 1, except that the zeolization temperature in Comparative Example 1 was 180°C and the zeolization time was 6 hours. Catalytic reaction was carried out in the same manner as in Example 1. The results are shown in Table-2.

Comparative Example 3 The catalyst obtained in Comparative Example 2 was subjected to the same operation as in Example 3 to make it into a lanthanum type and a reaction was carried out. The results are shown in Table-2.

Comparative Example 4 The zeolization temperature and time of Comparative Example 1 were changed to 180°C, 8
A highly crystalline aluminosilicate was obtained by carrying out the same operation as in Comparative Example 1, except that the time was changed and the organic additive was changed to tetramethylammonium.

This highly crystalline aluminosilicate was catalyzed and reacted in the same manner as in Example 1. The results are shown in Table 1.

Table-1 *l Conversion rate from methanol to hydrocarbons *2 Total composition of ethylene, propylene, and butene-2 [Effects of the invention] As is clear from the above results, when the present invention is used,
Lower olefins such as ethylene, propylene, and butene can be obtained from methanol at high conversion rates. This also applies when dimethyl ether is used in place of methanol.

Claims (4)

[Claims] (1) A solid material containing crystalline aluminosilicate is produced by holding an aqueous raw material mixture containing a silica source, an alumina source, an alkali metal salt, and a choline compound under hydrothermal synthesis conditions in which the choline compound does not vaporize or decompose. A part of the solid material containing crystalline aluminosilicate obtained in the seed isomorph synthesis step is used as a seed, and an aqueous raw material mixture containing this, a silica source, an alumina source, an alkali metal salt, and a choline compound is vaporized. or the crystalline aluminosilicate obtained from the crystalline aluminosilicate production process maintained under hydrothermal synthesis conditions that do not decompose, is calcined at a high temperature to convert at least a part of it into the H (proton) form, or at least a part of the alkali metal is converted into the H (proton) form. 1. A method for producing ethylene-rich olefins, which comprises using a catalyst partially exchanged with polyvalent metal ions and contacting it with methanol and/or dimethyl ether at high temperature and under normal to high pressure. (2) the crystalline aluminosilicate production step includes at least two steps, and only the first step uses as a seed a part of the solid material containing the crystalline aluminosilicate obtained in the seed solid material synthesis step; The method for producing ethylene-rich olefins according to claim 1, wherein a part of the crystalline aluminosilicate-containing solid material obtained in the production process is used as a seed for the production process thereafter. (3) Claim No. (3) characterized in that the carbonaceous material deposited as a catalyst through a catalytic reaction is periodically burned and removed.
The method for producing ethylene-rich olefins according to item 1) or (2). (4) The crystalline aluminosilicate manufacturing process includes at least two steps, and only the first step uses a part of the solid material containing the crystalline aluminosilicate obtained in the solid material synthesis step as a seed. Thereafter, a part of the solid material containing crystalline aluminosilicate obtained in the manufacturing process is used as a seed for the manufacturing process. manufacturing method.