JPS60114339A - Production of absorbing and separating agent for unsaturated hydrocarbon - Google Patents

Abstract

PURPOSE:To obtain the titled solid separating agent having less deterioratability with water by bringing an org. solvent soln. of silver halide, Al halide and an org. compd. having arom. ring into thorough contact with porous inorg. oxide then removing the free org. solvent. CONSTITUTION:An org. solvent (e.g., toluene) soln. of silver halide (e.g., silver chloride), Al halide (e.g., Al chloride) and an org. compd. having >=2 arom. rings (e.g., straight chain polystyrene) is brought into thorough contact with porous inorg. oxide such as silica then the free org. solvent is removed thereby producing a solid absorbing and separating agent for unsatd. hydrocarbon. Such separating agent has highly selective absorbing and separating performance of unsatd. hydrocarbon such as ethylene and is extremely less deteriorative against water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an unsaturated hydrocarbon absorption and separation agent,
In particular, the present invention relates to a method for producing the above-mentioned solid separation agent that selectively absorbs unsaturated hydrocarbons and is less susceptible to water deterioration.

Conventionally, the formula M1M1rXn aromatic (Ml:
Group 1-B metals such as Cu, Ml: Summer of Az, etc.
Group A metals,
A liquid absorbent consisting of an aromatic hydrocarbon or hepgenated aromatic hydrocarbon solution of a dimetallic salt complex (JP-A-57-2
(Japanese Patent Publication No. 1328), bimetallic salts having auhtx4 (x : ) s rogen atom) (Japanese Patent Publication No. 48-35041)
However, in all of these, the effective gas absorption component itself is unstable, and the absorption performance deteriorates in a short period of time, especially if moisture is present in the gas to be treated.

In addition, recently, liquid or solid complexes such as silver halide, aluminum halide, and polystyrene have been announced as polymeric metal complexes that have the ability to separate ethylene from mixed gases (Japanese). Chemical Society Showa 5
(See ``Polymer metal complex with ethylene separation function'' by Hirai et al., Autumn Annual Meeting 2003, 2003). However, like the above-mentioned unsaturated hydrocarbon absorbent, this complex is highly susceptible to moisture deterioration in a liquid state, and cannot stably absorb and separate ethylene for a long period of time.

Furthermore, there are problems in that the water resistance is low even in the solid state, and the amount of silver halide and aluminum halide (I[l) that can be supported is small.

The present invention eliminates these drawbacks and proposes a method for producing a solid unsaturated hydrocarbon absorption and separation agent that has highly selective absorption and separation performance for unsaturated hydrocarbons and has extremely low deterioration with water. It is something to do.

That is, the present invention involves bringing an organic solvent solution of silver halide, aluminum 10 degenide (I[l) and an organic compound having two or more aromatic rings into sufficient contact with a porous inorganic oxide, and then removing the free organic solvent. The present invention relates to a method for producing an unsaturated hydrocarbon absorbing and separating agent.

Note that the unsaturated hydrocarbons in the present invention include ethylene,
It is a general term for olefins such as propylene and butene, dienes such as butadiene, and unsaturated hydrocarbons such as acetylenes (hereinafter referred to as ethylenes).

As the 710 g of silver halide in the method of the present invention, chlorine, bromine, iodine, and fluorine are all effective, but silver chloride is usually used due to cost and ease of availability.

Aluminum halide (Chlorine, bromine, iodine, and fluorine are all effective as halogens for El, but aluminum chloride is usually used for the same reason as above.) Aluminum halogenide (II) Since it generally contains impurities, it is used after being prepared by a sublimation method or the like, but it does not need to be purified to a high degree as in the conventional solution method described above ().

In addition, examples of the organic compound having two or more aromatic rings in the method of the present invention include those having a relatively low molecular weight such as diphenylmethane, and aromatic polymers having a relatively low molecular weight such as linear polystyrene. However, due to problems with the preparation method, linear polystyrene or its derivatives which are soluble in organic solvents are preferred. The molecular weight of such linear polystyrene is 200 or more, preferably 500 to 5000, and more preferably 800 to 10,000.

Further, the above-mentioned polystyrene modified product may be used as long as it is soluble in the organic solvent used in the method of the present invention.

Further, as the organic solvent in the method of the present invention, general-purpose solvents such as (7) aromatic compounds such as benzene, toluene, and xylene, carbon disulfide, and dichloromethane are used.

However, the above silver halide, aluminum halide (
[1] and solvents that do not have the ability to dissolve organic compounds having two or more aromatic rings, or solvents that decompose, reduce, or oxidize these compounds are not preferred. For example, carbon tetrachloride and chloroform have significantly lower solubility of aluminum halide (III) than the above-mentioned aromatic compounds, making them unsuitable for use in the method of the present invention.Also, the solvent generally contains water. aluminum halide (I)
Water should be strictly avoided in the solvent used, since [Il is partially decomposed to generate solid content and hrogonic acid].

In addition, the absorption/separation agent obtained by the method of the present invention is a product in which a complex salt and an inorganic oxide as a carrier are integrated as described below, and the aluminum halide side of the complex salt is an inorganic oxide as a carrier and an aromatic ring. It is presumed that hydrophobicity is maintained due to the cooperative action of an organic compound having two or more of these and an organic solvent. (■), aromatic ring 2
It is preferable to use an organic solvent that has the ability to sufficiently dissolve not only organic compounds having 1 or more organic compounds but also compounds (complex salts) formed from these by the heating operation described below.

Therefore, in the method of the present invention, benzene, toluene,
Aromatic compounds such as xylene are mentioned as preferred organic solvents.

In the method of the present invention, the above-mentioned silver halide and aluminum halide (Il) are dissolved separately or together in an organic solvent, and an organic compound having two or more aromatic rings is added and dissolved. The contact method is impregnation method, immersion method, spray method, etc., and in particular, do not use more organic solvent than necessary, and use an amount almost corresponding to the pore volume of the inorganic oxide. An impregnation method is generally used, in which the amount of solution is sufficient.

Incidentally, the ability of the method of the present invention as an absorption/separation agent is that when silver acts in a monovalent state, it exhibits remarkable ethylene selectivity and absorbability.

Aluminum halide (I[) has the function of holding this silver in a monovalent state, and in particular, both are present in equimolar amounts in the complex salt described below [for example, AgA7X4 (X: halogen,
It is thought that the ability is at its maximum when it exists.

Therefore, in the method of the present invention, in order to form such a complex salt, after bringing the above-mentioned organic solvent solution into sufficient contact with the porous inorganic oxide, the solution is heated for 40 min in the absence of water, preferably in an inert gas. ~601Z', a heating operation is performed for 8 to 6 hours. By this heating operation, Ag (11, A7 (
A complex salt consisting of llrl, an organic compound caused by an organic solvent, and It is estimated that By this heating operation, a portion of the free organic solvent is also removed.

Note that the above heating operation may be performed before the organic solvent solution is brought into contact with the porous inorganic oxide.

As mentioned above, the molar ratio of silver halide to aluminum halide (Shu) is preferably 1:1, and it is desirable that no excess aluminum halide (11) be present.

The concentration of the organic solvent solution may be such that silver halide, aluminum halide) and an organic compound having two or more aromatic rings can be dissolved therein. It is necessary to dissolve it in Generally, the solution concentration and amount may be such that the total amount of silver halide, aluminum halide (1), and an organic compound having two or more aromatic rings is supported by 5 to 50 wt% based on the inorganic oxide. . Also, aromatic ring 2
The weight ratio of the organic compound having at least 100% to silver halide or aluminum halide (nIl) is preferably in the range of 0.2 to 5, particularly 0.4 to 2.

The porous inorganic oxide used is one that has the ability to sufficiently disperse silver halide, aluminum halide (] [l, and an organic compound having two or more aromatic rings. However, Ag (114r: The R element must not be oxidized and must not decompose aluminum halide (Il).

Such porous inorganic oxides preferably do not contain free water and have a sufficient surface area. If the surface area is too large, silver or aluminum is fixed and inactivated more than necessary, and the pores become too small, reducing the dispersibility of the complex salt. Therefore, 110-1200c
, preferably 450 to +1 OQi: 1, more preferably 5
Baked at 00-900C, BICT surface area -40
~400m2/11, preferably 50~350m27y, is used. Specific examples include alumina, silica, silica alumina, titania, silica magnesia, zirconia, alumina magnesia, and the like. Among them, those showing excellent dispersion compatibility are alumina, silica, and silica-alumina. In particular, because of their adjustable pore structure, they uniformly disperse and immobilize organic compounds having two or more aromatic rings. Alumina has the best ability to do this.

In the method of the present invention, after the above-mentioned contacting and heating operations, the free organic solvent is removed under reduced pressure. At this time, heating (
That is, heating at 40 to 6 oC in a moisture-free state, preferably in an inert gas, can also be added. It is important to carry out this removal operation until the organic solvent in the liquid phase is exhausted. This is because the solid absorption and separation agent produced by the method of the present invention exhibits sufficient water resistance when Ag (11 and AI!
This is the case when IJ is completely immobilized on the porous inorganic oxide support and the organic compound having two or more aromatic rings is dispersed and immobilized, and the free organic solvent is retained in the pores in a liquid phase. This is because, if it is present, the selective absorption performance of ethylene will be easily deteriorated by water, as seen in the conventional liquid absorbent mentioned above.

Hereinafter, the method of the present invention will be explained in more detail with reference to Examples.

[Example 1] Aluminum chloride (IJ is a commercially available special grade reagent (in this case, manufactured by Kishida Kagaku Kogyo C Co.)) was purified by the sublimation method and the cotton material was removed, and toluene was used as a commercially available special grade reagent. reagent(
Here, Wako Tsumugi Kogyo Co., Ltd. (manufactured by Co., Ltd.) was used after dehydration with metallic sodium and distillation. As silver chloride, a commercially available special grade reagent (here, manufactured by Kojima Chemical Co., Ltd.) was used as it was.

The above aluminum chloride (@0.81/(6va m
ol), the above silver chloride 0. a I (6mn+o/
) and polystyrene II with a molecular weight of 2200 were added, and 201 g of toluene was added to dissolve them, and the mixture was heated and kept warm at 50 C for 6 hours while stirring by rotating a tetra-tar. In addition, the above nitrogen is commercially available nitrogen (here, manufactured by Teikoku Sanso C Co., Ltd. with a purity of 99.999%), and immediately before use, commercially available Molecular Sieve 3A (here, manufactured by Nikka Seiko C Co., Ltd.) is used. The product was purified by passing it through a packed column.

On the other hand, another (1) commercially available alumina A carrier (manufactured by Catalysts Kasei, with an average pore diameter of 108A,
After putting 101 pieces of BIET (surface area 230 II + 2/i) into the eggplant flask and thoroughly deaerating the inside of the eggplant flask using a vacuum pump, using a dropping funnel, add I! A toluene solution of aluminum chloride CI[+, silver chloride and polystyrene was added. After stirring for 10 minutes, the pressure inside the rotary evaporator was reduced (66 Hg) and the mixture was left to stand day and night to sufficiently remove toluene and prepare an absorbent.

To confirm the performance of this absorbent, the absorbent was placed in a 200-cm rotary evaporator and heated with a mixed gas of 1 atm of ethylene and nitrogen (ethylene partial pressure: 0.80 atm).
, nitrogen partial pressure 0.20 atm) 14, and ethylene absorption operation was carried out at 26C while rotating and agitating the rotary evaporator. This absorption operation was carried out by circulating a mixed gas of ethylene and nitrogen at a rate of 1.4 rpm over the absorbent using an air pump. The mixed gas of ethylene and nitrogen is a commercially available product (purity ethylene: 79.99%, nitrogen: 20.01% manufactured by Tetsu Seikagaku Kogyo Co., Ltd. 3).
Immediately before use, add a commercially available oxygen scavenging group (Nikka Seiko C strain 3!It!
The purified product was used.

Ethylene absorption was measured at 26C using the gas buret method. Ethylene absorption is rapid, and the amount of ethylene absorbed after 10 minutes is 2. It was Omrnol.

The absorbent was then heated to 90C at latm to release the absorbed ethylene.

On the other hand, nitrogen gas (refined commercial product mentioned above) 1! By combining a container containing distilled water with an air washing bottle containing distilled water, and passing nitrogen gas through the air washing bottle with an air pump,
Water (20,000 ppm) with a saturated steam fraction of 1:' was mixed into nitrogen gas, and the gas was circulated for 10 minutes at 0.8 J3/win over the above absorbent after ethylene release (hereinafter referred to as This operation is called water treatment).

Thereafter, this absorbent was heated to 26C, and while the evaporator was not rotating, it was heated to a mixed gas of ethylene and nitrogen at latm (ethylene partial pressure 0.80 atm, nitrogen partial pressure 0.20 atm).
m) (purified product from the above-mentioned commercial product) was combined with a container containing No. 1, and the mixture was circulated over the absorbent using an air pump to perform the ethylene absorption operation again.

The absorption of ethylene in this case was also rapid, with 2.2 mmol of ethylene being absorbed after 10 minutes.

The absorbent was then heated to 9 (IC) at latm to release the absorbed ethylene.

Thereafter, the water treatment, absorption, and release described above were repeated, and the amount of ethylene absorbed was measured. The results are shown in Table 2 below.

[Examples 2 to 7] The same operations as in Example 1 were performed except that the organic solvent, polystyrene, and inorganic oxide of Example 1 were replaced with those shown in Table 1. The amount of ethylene absorbed is also shown in Table-2.

Table-1 X silica: Product name ID GEL (5
5011: Calcined product, BET surface area 300 m2/I) Mine*Alumina B carrier: Alumina λ carrier (used in Example 1) further calcined at 800 C (B+rr surface area tsom2/#) [Example 8] Implementation The same absorbent as in Example 1 was prepared, and the mixed gas to be absorbed was replaced with a mixed gas of 1 atm of acetylene and nitrogen (acetylene partial pressure 0.78 atm).
Similar adsorption/desorption experiments were repeated using a gas with a nitrogen partial pressure of 0.22 atm) to obtain the results shown in Table 3.

Table 3 The mixed gas of acetylene and nitrogen is commercially available acetylene (
Nitrogen (100% purity manufactured by Japan Special Gas Co., Ltd.) and commercially available nitrogen (same as the one manufactured by Teikoku Sanso Co., Ltd. used in Example 1) were mixed, and the mixture was prepared in the same manner as in Example 1 immediately before use. The product was purified by passing it through an oxygen removing group.

[Comparative Example 1] Under dry nitrogen, 0.0.
811 (6 m mol of aluminum chloride (8).

0.81/(6ya gnat) of silver chloride and p+
Polystyrene II (molecular weight 2200) was added and dissolved in toluene 201, and heated and kept at 60C for 2 hours while stirring using a magnetic stirrer to prepare a liquid absorbent.

The above liquid absorbent was placed in a No. 2001 Nironas flask, and a mixed gas of ethylene and nitrogen at 1 atm (ethylene partial pressure 0.80 atm, nitrogen partial pressure 0.20 a) was added.
tm ) (The same purified commercial product as in Example 1 was used; the same applies hereinafter) 1! The mixture was combined with a container containing ethylene and stirred using a magnetic stirrer to absorb ethylene at 26C. The mixed gas of ethylene and nitrogen was circulated at 1.4 Jl/win using an air bong and passed over the absorbent.

Ethylene absorption was measured at 26C using the gas burette method. Ethylene absorption was rapid, and the amount of ethylene absorbed after 10 minutes was 5.5 trr mol.

The absorbent was then heated to 9 DC at + atm n to release the absorbed ethylene.

On the other hand, a container containing nitrogen gas (purity 99.999%) (used the same purified commercial product as in Example 1) 1-13 was combined with an air washing bottle containing distilled water, and an air pump was used to fi26t by passing gas through the air washing bottle? Water (20,000 ppm) at a saturated vapor pressure of
Circulated for 10 minutes at e/ll1in.

After that, this absorbent was heated to 26C and the evaporator was rotated, and a mixed gas of ethylene and nitrogen of 1 aim (ethylene partial pressure 0.80 atm, nitrogen partial pressure 0.20 atm
) It was combined with a container containing 1-e and circulated over the absorbent using an air pump to absorb ethylene again.

The amount of ethylene absorbed at this time was 0.8 mmol.

As is clear from the above Examples and Comparative Examples, the ethylene absorption and separation agent produced by the method of the present invention has extremely low deterioration with water and can be stably used for absorption and separation of ethylene for a long period of time. be.

Claims (1)

[Claims] (11) An organic solvent solution of silver halide, aluminum halide (NJ) and an organic compound having two or more aromatic rings is brought into sufficient contact with a porous inorganic oxide, and then the free organic solvent is removed. A method for producing an unsaturated hydrocarbon absorption/separation agent characterized by: (2) using linear polystyrene, a derivative thereof, or a modified product thereof that is soluble in an organic solvent as the organic compound having two or more aromatic rings; Claims characterized in (
1) The method described. (3) The method according to claim (1) or (2), characterized in that alumina, silica, or silica-alumina is used as the porous inorganic oxide.