JPS58135118A - Absorption and separation of carbon monoxide - Google Patents

Abstract

PURPOSE:To separate CO from a water-containing mixed gas, economically, in an industrial scale, by usung a CO-absorption liquid composed of 2-20-mer of styrene or its derivative, a Cu(I) halide and an Al(1A73) halide. CONSTITUTION:The objective CO-absorption liquid can be prepared by mixing a 2-20-mer of styrene or its derivative with Cu(I) halide and AlIII halide, and stirring the mixture at about 20-90 deg.C for several hours. When the absorption liquid is brought into contact with a CO-containing mixed gas, CO is rapidly absorbed and separated from the mixture. The absorbed CO can be released rapidly by heating the liquid at about 110-150 deg.C. Since the absorption liquid is stable against water, it can be used in the separation of CO from a mixed gas containing >=1ppm of water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating -carbon oxide from a mixed gas containing carbon monoxide along with nitrogen, oxygen, methane, carbon dioxide, hydrogen, and the like.

- Carbon oxide is a basic raw material in synthetic chemistry, and is produced from coke and coal using generator furnaces, water gas furnaces, Winkler furnaces, Lurgi furnaces, Kotspers furnaces, etc. It is also produced from natural gas and petroleum hydrocarbons by steam reforming and partial oxidation methods. In these methods, the product is obtained as a mixture of gases such as carbon oxide, hydrogen, carbon dioxide, methane and nitrogen. This mixed gas also contains a small amount of water. For example, for water gas,
- Carbon oxide 35-40%, hydrogen 45-51%.

4-5% carbon dioxide, 0.5-1.0% methane, 4% nitrogen
It has a composition of 1000 to 20000 ppm of water. Carbon monoxide, a by-product of steel mills, oil refineries, and petrochemical plants, is similarly obtained as a mixed gas.

In order to use these -carbon oxides as raw materials for synthetic chemicals,
It is necessary to separate carbon monoxide from the mixed gas.

Hydrogen is an important raw material in the chemical industry, and can be used as the various mixed gases mentioned above or in 2. It is separated from the waste gas of petrochemical plants, for example from the hydrocarbon dehydrogenation process, and often contains small amounts of carbon monoxide. Since this carbon oxide becomes a catalyst poison for the catalyst of a reaction using hydrogen, it is necessary to separate and remove it. Also, in these waste gases.

It usually contains a small amount of water.

According to British Patent No. 1,318,790, when a toluene solution of copper aluminum tetrachloride (Cu (AI C14)) is brought into contact with a mixed gas containing 30 mo1% of carbon monoxide at 25°C, -oxidation occurs. It is stated that by absorbing carbon and heating it to 80°C, 95 Ti of carbon monoxide can be recovered. This absorption liquid has advantages such as being unaffected by hydrogen, carbon dioxide, methane, nitrogen, and oxygen contained in the mixed gas and having a low absorption pressure. However, the separation method using this absorption liquid is: 1) Copper aluminum tetrachloride.

Since it irreversibly reacts with water in the mixed gas to inactivate it, + D, J, Haas is required for industrial implementation.
Chemica
l Engineering Progress Magazine, No. 7
As stated in Volume 0, No. 5, May 1974, page 76, water in the mixed gas must be strictly controlled to 1 ppm or less; 2) - Carbon oxide absorption is - 10℃ to 40℃ or lower 2 Usually carried out at 25℃, so it is common.

It is necessary to cool the mixed gas obtained at 60°C or higher to 25°C, and 3) the carbon monoxide released by heating to 80°C in the recovery process is saturated with the vapor of toluene, which is a solvent. Therefore, it has drawbacks such as the need for a step to separate toluene.

Two other methods have been proposed, but these methods for separating carbon monoxide from mixed gases are still far from completely satisfactory.

The inventors of the present invention have conducted extensive research to solve these problems, and have found that they are stable against water in the mixed gas.

Discovered a carbon monoxide absorbing liquid that can absorb carbon monoxide at temperatures of 50 to 100°C or higher, and does not require a process to recover solvent vapor.

The invention has been completed.

The purpose of the present invention is to industrially advantageously separate and purify or separate and remove carbon monoxide from a mixed gas containing water. ) and aluminum halide as a carbon monoxide absorbing liquid.

To explain the present invention in more detail, the carbon monoxide absorption liquid used in this method contains 20 or 20 mer of styrene, rene or their derivatives together with copper (1) halide and aluminum halide (20). ~90℃
It can be prepared by keeping it warm for several hours and stirring it.

Describe it in the specification. What are styrene derivatives? :t
For example, α-methylstyrene, 1,1-diphenylethylene, 1 or 2 methyl groups at the 2, 3 or 4 position,
These include aromatic substituted styrene having an ethyl group or a halogen. If non-aromatic carbon-carbon double bonds are present in these n41 bodies, side reactions may occur during the preparation of the carbon oxide absorption liquid or the separation of carbon monoxide. , it is desirable to make it unsaturated by hydrogenation etc. in advance.

Examples of the copper halide used in the present invention include:

Chlorinated steel (1), copper fluoride (1), copper bromide (1), etc. Aluminum halide (1) used in the present invention
) is, for example, aluminum chloride (rin).

Aluminum fluoride (厘) and aluminum bromide (1
) etc.

Regarding the composition of the absorption liquid used in the present invention, the molar ratio of 2- to 20-mer monomer residues of styrene or its derivatives and copper (1) halide is 0.02 to 10.
．． Preferably it is 0.5 to 3, and the molar ratio of copper(I) halide to aluminum halide is 0.01 to 3.
10. Preferably it is 0.5 to 1.5.

The carbon monoxide absorbing liquid according to the present invention was added at 20 to 10
When brought into contact with a mixed gas containing carbon monoxide at 0°C, preferably 60-80°C, carbon monoxide is rapidly absorbed. - Carbon oxide is rapidly released by heating the absorption liquid to 110-150°C, preferably 115-140°C. -Absorption of carbon oxide reduces the pressure of the mixed gas to 1
By setting the temperature to be at least atmospheric pressure, it is possible to carry out the process even at 100° C. or higher.

The carbon monoxide absorption liquid according to the present invention is stable to water. For example, as seen in the Examples.

First, the absorption liquid was brought into contact with a nitrogen stream containing 8,700 ppm of water at 70°C for 10 minutes, and then brought into contact with high-purity carbon monoxide to absorb carbon monoxide.

- Almost no decrease in carbon oxide absorption capacity is observed.

In the present invention, the step of recovering 2- or 20-mer of styrene or its derivatives is often carried out because the vapor pressure of these compounds is low.

do not need.

Next, the present invention will be further explained by examples.

[Example 1] Aluminum chloride (1) was used by dehydrating and purifying a special grade reagent manufactured by Kishida Chemical Industry Co., Ltd. using a vacuum sublimation method.

The polystyrene oligomer is A made by Toyo Soda Co., Ltd.
-300 (degree of polymerization: 2.3, 4, 5.6, molar fractions of polymers 7 and 8, respectively.

24chi, 32%, 22%, 13chi, 6chi, 2chi and 1
(mixture) was used. As copper chloride (1), a special grade reagent manufactured by Koso Chemical Co., Ltd. was used. - Carbon oxide gas and nitrogen gas were manufactured by Takachiho Chemical Co., Ltd. (
(purity 99.95%) and Suzuki Shokan Co., Ltd. (purity 9
Immediately before use, Pombe gas (9.999%) was dried and purified by passing it through a packed column of Molekiller Sheep 3A (manufactured by Nikka Seiko Co., Ltd.).

Under dry nitrogen, 2.4. ! i' (18 mmol) of aluminum chloride (I), 1.8 g (18 mmol) of copper chloride (
(2) and 10.0 g (106 mmol residue equivalent) of polystyrene oligomer were added and stirred using a magnetic stirrer.

An absorption liquid was prepared by heating and keeping at 70°C for 4 hours.

200mA! The absorption liquid was stirred using a magnetic stirrer at 70°C in a 1st m
Mixed gas of carbon monoxide and nitrogen (-carbon oxide partial pressure 0.9
Atm, nitrogen partial pressure 0.1 atm) Il was combined with a container containing -carbon oxide e, l' (2).For the initial 10 minutes of absorption, a BA-106T air pump manufactured by Iwaki Co., Ltd. was used. Then, the mixed gas was circulated and passed over the absorption liquid. - The carbon oxide absorption gas was measured at 20°C by the gas bead method. - The absorption of carbon oxide was rapid, and after 3 minutes, 4.6 mmol was absorbed. The amount of carbon monoxide absorbed after 20 minutes is 6.3 mmol.
Equilibrium absorption was reached.

The absorption liquid was heated to 125° C. at 1 atm, and the amount of gas released was measured by the gas buret method. - Carbon oxide was rapidly released, the amount released reached 6.3 mmol after 5 minutes.

Next, separately, 1 atm of nitrogen gas containing 32 mp (1,8 mmol) of water (water concentration 8,700
ppm) 5 l was prepared. Connect this container containing nitrogen gas to the Nironas flask of 2001111.
It was circulated using a BA-106T air pump manufactured by Iwaki Co., Ltd., and passed over the absorption liquid stirred by a magnetic stirrer at 70° C. for 10 minutes.

Thereafter, while stirring this absorption liquid at 70°C using a magnetic stirrer, a mixed gas of carbon monoxide and nitrogen at latm (- carbon oxide partial pressure 0.9 atm, nitrogen partial pressure 0.1
Atm) 11 was connected to a container, and an air pump was used to circulate the absorption liquid over the absorption liquid to absorb carbon oxide. - Carbon oxide absorption is rapid.

The absorption amount after 20 minutes was 6.3 mmol, which almost reached the equilibrium absorption amount. That is, the absorption rate and amount of -carbon oxide hardly changed from the values before contacting the absorption liquid with a gas containing 8,700 ppm of water. When this absorption liquid is heated to 125°C at 1 atm, -
Carbon oxide is released quickly, and the amount released is 6.3 m after 5 minutes.
reached mol.

Patent applicant Hidefumi Hirai

Claims (1)

[Claims] Copper halide (1), aluminum halide)
. It is characterized by using an absorption liquid composed of n-mers of styrene or its derivatives. A method for separating carbon monoxide from a mixed gas containing 1 ppm or more of water. Here, n is an integer from 2 to 20.