JPS59172428A - Separation of ethylene through absorption - Google Patents

Abstract

PURPOSE:To obtain ethylene from a mixed gas easily and advantageously with respect to technology and economy, by using a liquid absorbent consisting of a silver halide, an aluminum halide, polystyrene or a polystyrene derivative and an aromatic hydrocarbon. CONSTITUTION:In separating ethylene from a mixed gas containing carbon monoxide, nitrogen, oxygen, methane, ethane, carbon dioxide, hydrogen, and ethylene, a liquid absorbent consisting of a silver halide such as silver chloride, silver fluoride, silver bromide, etc., an aluminum halide, such as aluminum chloride, aluminum fluoride, etc., polystyrene or a polystyrene derivative, and an aromatic solvent such as benzene, or toluene (preferably a molar ratio of aromatic residue of polystyrene or polystyrene derivative to silver halide is 1-5, a molar ratio of silver halide to aluminum halide is 1-1.5, and a molar ratio of aromatic solvent to silver halide is 3-10) is used.

Description

[Detailed description of the invention] The invention includes - carbon oxides, nitrogen, oxygen, methane.

] [Related to a method for separating ethylene from a mixed gas containing ethylene along with methane, carbon dioxide, hydrogen, etc.

Ethylene is also an important basic material in the chemical industry and is produced by pyrolysis of saturated hydrocarbons such as natural gas, refinery gas and petroleum fractions.

However, off-gas produced by fluid catalytic cracking equipment and purge gas from various processes can also contain a considerable amount of ethylene. However, in these cases, ethylene is usually -carbon, nitrogen, oxygen.

It is obtained as a mixed gas containing ethylene along with methane, ethane, carbon dioxide, hydrogen, etc.7.

In addition, this mixed gas usually has a range of 2, 1ooo to 2000
Contains 0 ppm of water. Therefore, in order to use ethylene as an ingredient in the chemical industry, it is necessary to separate the ethylene from the mixed gas.3 To obtain a large amount of high-purity ethylene, there is a cryogenic preparative method. This is a method of cooling and liquefying the mixed gas and fractionating it in a low stage 1 at -95 to -140°C, but it requires complicated refrigeration and heat recovery/stem, and requires high-grade equipment. is expensive and 9 cm.
Power/1! There are disadvantages such as high i-costs. Furthermore, if the mixed gas contains water, carbon dioxide, etc., a blockage accident may occur in the low temperature layer/system, so it is necessary to remove water and carbon dioxide to 1 ppm or less using pretreatment equipment. be.

According to U.S. Pat. No. 3,651,159, copper(I) aluminum chloride (7i) has been shown to have the ability to separate ethylene by complexing with ethylene, but , ΦAluminum chloride (I) reacts strongly with water and irreversibly loses its ability to absorb ethylene, so even with 1 ppm of water, the amount of deactivation gradually increases as the throughput of the mixed gas increases. -C has the disadvantage that equipment corrosion progresses due to hydrogen chloride generated in one reaction.

'! (I) Since aluminum absorbs not only ethylene but also carbon monoxide, carbon monoxide is mixed into the ethylene separated from the mixed gas containing -carbon oxide.

Other 7I, /z methods have been proposed, but there is no method to separate ethylene from a mixed gas that requires id:, 4 to be completely added to /i14.

Surprisingly from the standpoint of these prior art techniques, the present inventors have discovered that silver halide, aluminum halide,
．． A solution composed of polystyrene or a polystyrene derivative and an aromatic solvent has the ability to absorb and release ethylene under mild conditions, and is stable against water in the mixed gas and resistant to carbon monoxide. It was discovered that the material showed almost no absorption capacity. Based on this discovery, as a result of intensive (iJt) research, we succeeded in separating and purifying or separating and removing ethylene from a mixed gas in an easy and advantageous manner, both technically and economically.
The invention has been completed.

The liquid absorbent in the present invention is silver halide.

It can be prepared by dissolving aluminum halide and a polystyrene agent or a polystyrene derivative in an aromatic solvent, keeping the solution at 1° C. (usually 40 to 80° C.) for several hours, and stirring.

Regarding the silver halide, aluminum halide, and aromatic solvent used in the preparation of the liquid absorbent in the present invention, the silver halide may include halides such as silver chloride, silver fluoride, silver bromide, and silver iodide. For example, aluminum chloride, aluminum fluoride
Aromatic solvents such as aluminum, aluminum bromide and aluminum iodide are, for example, benzene, toluene, albinol, and trichloride.

For example, the styrene derivatives described in the specification γ(,).

α-methylstyrene, α-]ynylstyrene, 4J:
and stilbenes. Examples of ethylene derivatives used in combinations of styrenic agents or methylone derivatives include propylene, -butene, isobutyne, 3-methyl-1-butene, -pentene, and vinyl chloride. 3, ÷) L, dienes.

For example, isoprene and chloroprene can be used as a styrene agent (or copolymerized with a styrene derivative) and then hydrogenated to unsaturated bonds in the diene residue. The content of these copolymers is 6'', 1
0 to 99 moles, 30 to 90 moles. The degree of polymerization of the polymer and copolymer used is in the range of 2 to 10,000. .

Regarding the composition of the liquid absorbent used in the present invention, the molar ratio of aromatic ring residues of polystyrene and polystyrene derivatives to silver halide is 0.3 to 30. The molar ratio of silver halide to aluminum halide is preferably 0.5 to 20°, preferably 1.0 to 1.5.
It is. The molar ratio of aromatic solvent and Cl non-silver is:
0.5-30. Quiet L < r, J: 3-10
It is.

The absorption of ethylene in the present invention is as follows:
〜90℃, preferably at 0 to 40℃, Δ is formed, and the absorbent is 40-1.40℃! JJ'j:LI
The absorbed ethylene can be released by raising the temperature to 60 to 100°C or by removing the ethylene content IJ-. 1/ζ2 Liquid absorbent i of the present invention
qJ,.

As seen in implementation i ('ll 3, - carbon oxide!
Since it does not absorb, the selection +1+ before ethylene is diluted and high.

Six-shaped absorbent IJ1 according to the invention. Stable in water. As seen in Examples 1 and 2, the absorption capacity of the liquid absorbent remained unchanged even when repeated ethylene fractionation was performed from a mixture containing 0.6 mol% (6oooppn) of water. The low C of 7″Ll/I: Yes.

On the other hand, as shown in Comparative Example 1, an absorption liquid without adding polystyrene or a polystyrene derivative.

That is, when an absorption liquid composed of silver halide, aluminum halide, and an aromatic solvent is brought into contact with a mixed gas containing water, the ability to absorb ethylene is significantly reduced by 7 times. It is clear from this that the liquid absorbent of the present invention is superior.

The present invention will now be further explained with reference to Examples and Comparative Examples.

〔Example]〕

Aluminum chloride was obtained by dehydrating and purifying a special grade reagent manufactured by Kida Kagaku Kogyo Co., Ltd. using a vacuum sublimation method.

For silver chloride, use a special grade reagent manufactured by Kojima Chemical Co., Ltd.
Well, I used it. Toluene was used by distilling a first-class reagent manufactured by Hatahashi Fujiyoshi Shoten, dehydrating it with RJ thorium, and distilling it. Linear polystyrene 2. Polymerization degree 16 manufactured by Wako Junkuwa Co., Ltd.
After purifying the gelatinous reagent No. 00 to 1800 by reprecipitation using a chloroform-methanol system three times, the reagent was heated at 60°C.
It was dried under vacuum for 12 hours before use.

As the ethylene gas, a cylinder gas manufactured by Takachiho Chemical Co., Ltd. was used, and the water content was adjusted to 0.6 mol% (6oooppm). Nitrogen gas was manufactured by Suzuki Shokan Co., Ltd. (purity 99.9).
Immediately before use, the cylinder gas (99'%) was dried and purified by passing it through a packed column of Molecule Sieve 3A (manufactured by Nikka Seiko Co., Ltd.).

Under dry nitrogen, 6.97 g (52.3 mmol
) aluminum chloride, 8.249 (57,5 m
mol ) of silver chloride and 5.44 g (52.3 mmol per monomer residue) of linear polystyrene;
Add 50 ml of toluene to dissolve, and stir using a magnetic stirrer.

A liquid absorbent was prepared by heating and insulating at 80° C. for 4 hours.

1 o o rat 2]] eggplant flask at 20°C,
Mixed gas of 1 atm of ethylene (water content 0.6 mol%) and nitrogen 2980 le (ethylene 094 atm, nitrogen 00
6 atm) to absorb ethylene. For the initial 3 minutes of absorption, use BA-10 manufactured by Iwaki Co., Ltd.
A 6T type air pump was used to circulate the mixed gas over the liquid absorbent. The amount of ethylene absorbed is
It was measured at 20°C by the Rett method.

The absorption amount reached 24.7 mmol (43 moles of charged silver chloride).

The liquid absorbent was heated to 100°C at 1 atm while cooling the corrugated reflux device above the three-day eggplant flask with tap water.
was heated to release the absorbed ethylene. The amount released is 2
It reached 3.3 mmo+.

After cooling, the liquid absorbent was stirred again at 20°C using a magnetic stirrer, and 2980 m/(ethylene 0.94 The mixture was connected to a container containing nitrogen (0.06 atm), and the mixed gas was circulated through the liquid absorbent using an air pump to absorb ethylene. Absorption of ethylene is rapid, with 17.5 mmol after 3 minutes.
Absorbs ethylene (30 mol% of the charged silver chloride), and
The amount of ethylene absorbed after 0 minutes reached 24.7 mmol (43 moles of silver chloride charged).

That is, even when water is brought into contact with a mixed gas containing 0.6 molt, the absorption rate and absorption amount of ethylene by this liquid absorbent hardly change. A special grade reagent manufactured by Kida Kagaku Kogyo Co., Ltd. was dehydrated and purified using a vacuum sublimation method.

Silver chloride is a special grade reagent manufactured by Kojima Chemical Co., Ltd.
11''i! was used. Toluene was used by dehydrating a first class reagent manufactured by Takahashi Fujiyoshi Shoten with sodium thorium and then distilling it.

Linear polystyrene has a polymerization degree of 16 manufactured by Wako Pure Chemical Industries, Ltd.
00-1800 pelleted reagent.

After purification by Fq precipitation using a chloroporum-methanol system three times, the product was vacuum dried at 60° C. for 12 hours and used.

Ethylene gas was a cylinder gas manufactured by Takachiho Chemical Co., Ltd., and the water content was adjusted to 0.6 mol% (6000 ppm). Nitrogen gas was manufactured by Suzuki Shokan Co., Ltd. (purity 99.
Immediately before use, the gas cylinder (999%) was dried and purified by passing it through a packed column of Molecule Sieve 3A (manufactured by Nikka Seiko Co., Ltd.).

Under dry nitrogen, add 100 ml of two (
] 3.07 jj (23,0 mmo
l ) aluminum chloride, 3.309 (23,
0 mmol) of silver chloride ν and 2.40 g (23.0 mmol per monomer residue) of linear polystyrene,
Add 23ml of toluene and dissolve, stirring using a magnetic stirrer.

A liquid absorbent was prepared by heating and moisturizing at 50° C. for 4 hours.

That is, this liquid absorbent (/i) was prepared in the same manner as the liquid absorbent described in Example except that it contained silver chloride in the same molar amount as aluminum chloride.

A 100 ml three-day eggplant flask was heated to 20°C with a mixture of ethylene (06 mol of water) and nitrogen at 1 atm.
980+n/' (1 inch) 70.94 atm, nitrogen 0
．． 06 atm) to absorb ethylene. Initial stage of absorption: 3 minutes + d, B manufactured by Iwaki Co., Ltd.
A model A-1061 air bonzo was used to circulate the gas mixture past the liquid absorbent. The yield of ethylene was measured at 201C by the gas beet method.

Ethylene absorption is rapid, with 9.2 mmol (9.2 mmol) being absorbed after 3 minutes.
Absorbs ethylene (39 mol% of the charged silver chloride).

After 60 minutes, the amount of ethylene absorbed reached 11.4 mmol (49 moles of silver chloride charged). at 1 atm and 100℃
was heated to release the absorbed ethylene.

After cooling, this liquid absorbent was stirred again at 20° C. using a magnetic stirrer, and a mixed gas of ethylene (water content: 0.6 moles) and nitrogen at 1 atm was added to the mixture gas 2980 i+/! (
Add ethylene (0.94 atm, nitrogen 0.06 atm) and
It was connected to a vessel and an air pump was used to circulate the gas mixture over the Liquid 1 absorbent to absorb the ethylene. Absorption of ethylene is rapid, with 10.2 mmo after 3 minutes.
The amount of ethylene absorbed after 60 minutes is 1], 4. mmol (
The silver chloride charge reached 49 moles.

Again, while cooling the corrugated reflux device attached above the Nironas flask with tap water, add the liquid absorbent at 1 atm.
It was heated to 00°C to release the absorbed ethylene.

After cooling, the liquid absorbent was mixed with 1 atm of ethylene (containing 0.6 mol of water) and nitrogen at 20° C. while stirring using a magnetic oven. gas 2
980n+6 (x chilli l/: 10.94 atm, nitrogen 0.
The ethylene absorption amount was 8.9 mmol (138 mol% of the silver chloride charged) by circulating the mixed residue over the liquid absorbent using an air pump.
of ethylene, and the amount of ethylene absorbed after 60 minutes is 11
, 6 mmol (50 moles of silver chloride charged) was reached.

That is, even when brought into contact with a mixed gas containing 0.6-1 mol of water, the absorption rate and absorption amount of ethylene by this liquid absorbent hardly changed.

[Example 3] Aluminum chloride was obtained by dehydrating and purifying a special grade reagent manufactured by Gishida Chemical Industry Co., Ltd. using a vacuum sublimation method.

For silver chloride, a special grade reagent manufactured by Kojima Chemical Co., Ltd. was used. Toluene was used by dehydrating a first-class reagent manufactured by Takahashi Fujiyoshi Shoten with metallic sodium and then distilling it. Linear polystyrene has a polymerization degree of 1600 to 1 manufactured by Wako Pure Chemical Industries, Ltd.
800 pelleted reagents.

After purification by reprecipitation using a chloroform-methanol system three times, the product was dried under vacuum at 60° C. for 12 hours and used.

Carbon monoxide gas and nitrogen gas were gas cylinders manufactured by Takachiho Chemical Co., Ltd. (purity: 99.95%) and Suzuki Shokan Co., Ltd. (purity: 99.999%), respectively.

Immediately before use, it was dried and purified by passing it through a packed tower of Molecuy Lanbu 3A (manufactured by Nikka Seiko Co., Ltd.). .

= 100 mg covered with aluminum foil under dry nitrogen.

4.95 g (37.1 mmol
) of aluminum chloride, 5.32 g (37,1 mm
ol) of silver chloride and 3.87.9 (37.1 mmol per monomer residue) of linear polystyrene;
37 ml of toluene was added and dissolved, and while stirring using a magnetic stirrer, the mixture was heated and kept at 50° C. for 4115 minutes to prepare a liquid absorbent.

That is, this liquid absorbent was prepared in the same manner as the liquid absorbent described in Example 2.

The carbon monoxide absorption measurement method described below was also carried out in the same manner as the ethylene absorption measurement method in Example 2.

A 100 m/l three-day eggplant flask was combined with a container containing 298 Qml of a mixed gas of 1 atm of carbon monoxide and nitrogen (-094 atm of carbon oxide, 0.06 atm of nitrogen) at 20°C. Carbon oxide was absorbed. Absorption first 1 1 3
The mixed gas was circulated and passed through the absorption liquid for 2 minutes using a BA-106T type air bong manufactured by Iwaki Co., Ltd. 5I. -The carbon oxide absorption amount was measured at 20°C by the gas B-lett method. This liquid absorbent did not absorb carbon monoxide, and the amount of carbon monoxide absorbed after 120 minutes was Om(').

[Comparative example 1] The same reagents as described in Example 2 were used.

2.95 g (22,1 m 111
01 ) of aluminum chloride and 3.17 g (22,1
In the chlorination of tηn101), add t]4 and toluene 22
Add tJ and dissolve f'+Ql 1. , while stirring using a magnetic stirrer s 411, '11ifl +
jJll thermal insulation at 50℃! , then absorb the liquid 1.゛1 made,
Ta.

A 100 ml eggplant flask was heated at 20°C with a mixed gas of 1 atm I32 ethylene (water content 06 mol%) and nitrogen 2 (li80 m/+ (ethylene 0.94 atm, nitrogen 0.06 atm). ) to absorb ethylene /ζ.For the first 3 minutes of absorption, a 13A-106T air pump manufactured by Iwaki Co., Ltd. is used to circulate the mixed gas over the absorption liquid. The ethylene yield was measured at 20°C by the gas beet method.

Absorption of ethylene is rapid, after 3 minutes Ir:J-,8,9
Absorbs m m o 1 (40 mol% of charged silver chloride) of ethylene, and the ethylene absorption amount after 60 minutes is il + 1.11
,3 nuno I (51 mol% of the charged silver chloride) was reached.

Next, the absorption liquid was heated to 1 atm and 100 m
℃ to completely absorb/release ethylene.

After cooling, this absorption liquid was stirred at 20°C using a magnetic stirrer and heated to 1 atm of ethylene (water content 0.
Mixed gas of 6 moles 2 stones) and nitrogen 2980 m/! (0.94 atm of ethylene, 0.06 atm of nitrogen) was connected to the vessel and the mixed gas was circulated over the absorption liquid using an air pump to absorb the ethylene. Ethylene adsorption f□J: Rapid, 8.1 mm I (intrusion chloride) 36 mol% of the animal after 3 minutes, 9.9 mm after 60 minutes
The solution was vortexed with 45 mol % of silver chloride injected into the solution. Add 0.6 mol% of water to the water.
The ethylene absorption capacity of the absorbing liquid decreases by 13% due to contact with the mixed ethylene residue.

Next, take rJ 1 degree above the two-necked eggplant flask.
While cooling the girder-shaped corrugated pipe reflux device with tap water, the absorption liquid was heated to 100°C (1 atm) to absorb and completely release the ethylene.

After cooling, use a magnetic stirrer at 20℃ in Yamaga.
Since it is 1 atm, ethylene at 1 atm (amount of water a' is 0.
The mixture is combined with a container containing 2,980 ffle (0.94 atm of Egurene, 0.06 atm of nitrogen) of a mixture of 6 mol %) and nitrogen, and an air pump is used to circulate the mixed scum over the absorption liquid to produce ethylene. was absorbed. Absorption of Evulene is rapid, reaching 7.8 rnmo after 3 minutes.
Absorbs ethylene (35 mol% of silver chloride),
60 minute wave ethylene absorption amount (l-1: 8.6 mmo
I (39 mol % of the charged silver chloride) was reached. The ethylene absorption capacity (d:
Zara K 13Qoa・It's going to be a little messy.

Patent applicant Hideshi Hirai Procedure Ura iE (spontaneous) [l/'l
December 28, 1995 [To the Director General of the Japan Patent Office, Mr. Kazu Wakasugi, 16 1 Display of the matter 111 (Special Fraud No. 46163 2 of 1999, Issued (] 11
Name of Ethylene Absorption NE Method 3, Person who will correct 1 - Relationship with publication 4. Soviet Union 1iriri people
'(JE-Ni, "ir capital f'l black ward? 7i heaven i'
jl 14-10 Name Inui Hirai 4, Agent 158 Tunge 03 (720)
5058 Address 2-33-15 Higashi Tamagawa, l111'i-I Tani-ku, Tokyo゛""'""゛"IJ -
, , , ,H,:x.

, 3, ・gahe 6, Details of the amendment l () At the end of page 18, line 13, 1-1 onward >A
Add example 4 and ratio of bite example 2.

[Example 4] In the same manner as described in Example 1, 4.95 g (37,
aluminum chloride, 5゜32g (3
7.1 mmo, Q) 1! An ethylene absorption solution was prepared from 87 g (inside was leftovers; 37.1 mmon per 1i1i) of linear polystyrene and 37 ml of toluene. Pour this absorption liquid into a 100 mfL two-piece eggplant flask, and stir the absorption liquid with a magnetic stirrer (heater) at 16°C. When the N2 gas that passed was analyzed by gas chromatography (Vorapack Q sword ram, 2 m, 60 °C), the water content was 5.5%. That is, even after passing over the absorption liquid, the water content (1) remained almost unchanged from before passing.

[Comparative Example 2] In the same manner as described in Example 1, 4.95 g/37.
1 mmo, (j) aluminum chloride, 5゜32 g (
An ethylene absorption solution was prepared from 37.1 mmoJL of silver chloride and 3'm of toluene.

That is, this absorption liquid contains 3.87 g (3.87 g per monomer residue).
This was the same as the ethylene absorption liquid used in Example 4, except that it did not contain linear polystyrene (7.1 mmo).

Pour this absorption liquid into a 100 m double eggplant flask and
While stirring the absorption liquid with a magnetic stirrer at 6°C, 16°C N2 gas saturated with water (water content 5.5%) was added for 5 minutes.
Passage was performed for 1 min at a rate of 0 ml/s. Gas chroma the passing gas! - When analyzed graphically, the content of 9 pieces was 0.011%. That is, r! 8! It passes over the liquid collecting liquid (the water content is clearly small).

In other words, in the present invention, ice is not absorbed by the liquid absorbent and passes through it, so even if water is included in the mixed gas, the absorption capacity of the liquid absorbent is not reduced. Ethylene can be separated well from

that's all

Claims (1)

[Claims] 4. Using a liquid absorbent composed of silver halide, aluminum halide, polystyrene/- still polystyrene derivatives, and aromatic hydrocarbons.
'l: Sign. 'Method to separate ethylene from tfls gas.