JPS5854857B2 - Sansonojiyokiyohouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing trace amounts of molecular oxygen present in a fluid.

In chemical industry processes, trace amounts of molecular oxygen present in raw materials can inhibit normal chemical reactions, reduce the function of catalysts, or cause serious damage to equipment due to corrosive effects. This often has undesirable effects.

For example, in a chemical reaction using an organometallic compound such as triethylaluminum as a catalyst, the presence of a trace amount of oxygen easily causes deactivation of the catalyst.

For example, in radical polymerization reactions, oxygen often acts as a polymerization inhibitor or induces reactions other than the intended ones, making it difficult to control the reaction or degrading the quality of the product.

Furthermore, metal catalysts such as nickel, cobalt, and copper are altered by oxygen, resulting in a decrease in activity or an increase in side reactions.

Another example is the effect of oxygen in boiler water; in this case, the permissible concentration of oxygen is strictly regulated because trace amounts of oxygen can cause material corrosion.

Various strategies are employed to remove oxygen from feed fluids in chemical industrial processes where the presence of trace amounts of oxygen has an undesirable effect.

For example, in order to remove oxygen from a liquid, there are methods such as degassing by reducing the pressure, passing an inert gas such as nitrogen gas, and also adding a suitable reducing agent such as hydrazine or sodium sulfite to remove it by reaction. There are known methods to do this.

In order to remove oxygen from the gas, for example, in the case of nitrogen gas, it is common to bring it into contact with a heated piece of copper or a copper wire mesh.

However, these methods have not always had a sufficient oxygen removal rate, and some of the reagents used for oxygen removal remain in the pond.

The present invention provides an improved method for removing molecular oxygen present in a fluid.

That is, in the present invention, by bringing a fluid into contact with a copper-containing resin obtained by reducing a polymer complex compound of a polymer compound containing a pyridine skeleton in its structure and a copper salt,
The present invention relates to a method for removing trace oxygen from a fluid.

A method of removing oxygen from a fluid by utilizing the combination of metallic copper with molecular oxygen is known.

However, the reaction between metallic copper and molecular oxygen does not proceed at a practical rate at low humidity and must be accelerated by heating.

Furthermore, when the fluid from which oxygen is to be removed is water, copper oxides or hydroxides are eluted into the water, and therefore a separate step is required to remove them.

The present inventors have developed a copper-containing oxygen scavenger that can remove oxygen at a rate sufficient for industrial use even at low temperatures.

The oxygen scavenger used in the method of the present invention is a copper-containing resin (hereinafter simply a copper-containing resin) prepared by reducing a polymer complex compound of a polymer compound containing a pyridine skeleton in its structure and a copper salt. ).

The polymer compound containing a pyridine skeleton in its structure used in the method of the present invention is a polymer compound containing a pyridine skeleton in its main chain or side chain, for example, polymerization of a vinyl monomer having a pyridine skeleton. adjusted by.

Further, it is preferable that such a polymer compound is crosslinked with a suitable crosslinking agent to become infusible and insoluble.

Examples of vinyl monomers having a pyridine skeleton include 2
-vinylpyridine, 4-vinylpyridine, 2-methyl-
4-vinylpyridine, 2-methyl 2-vinylpyridine,
Examples include 5-vinylquinoline, (1) vinylisoquinoline, 3-vinylisoquinoline, and 8-vinylisoquinoline.

An example of a suitable crosslinking agent is divinylbenzene.

Monomers having a pyridine skeleton such as those exemplified above can also be copolymerized with suitable vinyl monomers such as styrene, acrylonitrile, or N-vinylpyrrolidone.

A polymer compound containing a pyridine skeleton in its structure can also be made into a macroporous type by adopting an appropriate adjustment method.

This macroporous resin gives particularly good results when carrying out the method of the invention.

The copper salt used in the method of the present invention may be a monovalent or divalent copper salt, as long as it can be chemically bonded to the nitrogen atom in the pyridine skeleton through a coordinate bond or an ionic bond.

Specific examples of such copper salts include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, copper nitrate, copper sulfate, copper formate, copper acetate, and copper propionate. be.

These copper salts and a polymer complex of a polymer compound containing a pyridine skeleton in its structure can be subjected to an appropriate reduction treatment to give a copper-containing resin.

Examples of the reduction treatment methods used in the method of the present invention include reduction treatment using a reducing agent and, in the case of specific copper salts, such as organic copper salts such as copper formate and copper oxalate, thermal decomposition treatment.

The reducing agents used here include hydrogen, carbon monoxide,
Examples include hydrazine, sodium borohydride, and sodium hydrosulfide.

The fluid to which the method of the present invention is applied does not matter whether it is gas or liquid.

Specific examples include gaseous fluids such as nitrogen gas, carbon dioxide gas, argon gas, carbon monoxide gas, ammonia, ethylene, propylene, butenes, butene, water,
alcohols (e.g. methanol, ethanol, propatools), amines (e.g. methylamine, ethylamine, diethylamine, triethylamine, pyridine)
, aliphatic and aromatic hydrocarbons (e.g. hexane, heftane, cyclohexane, benzene, toluene, xylene, styrene), esters (e.g. ethyl acetate, vinyl acetate, methyl acrylate, methyl methacrylate), carboxylic acids (e.g. formic acid). , acetic acid, propionic acid), ethers (e.g. diethyl ether, etrahydrofuran), nitriles (e.g. acetonitrile, acrylonitrile), aldehydes and ketones (e.g. acetaldehyde, acrolein, acetone, methyl ethyl ketone).

Although the method of the present invention can be carried out by a batch method, it is more practical to carry it out by a distribution method.

Although room temperature is sufficient for carrying out the method of the present invention, it is also possible to select a lower temperature or higher humidity if necessary.

However, it is not preferable to employ a high temperature of 200° C. or higher because it causes thermal deterioration of the polymer compound.

The oxygen scavenger used in the method of the present invention is easily regenerated after use and can be used repeatedly.

Regeneration is achieved by reducing the oxygen-oxidized copper-containing resin with the above-mentioned reducing agent.

Alternatively, the oxidized copper-containing resin is brought into contact with formic acid to form a polymer complex of copper formate and a polymer compound containing a pyridine skeleton in its structure, and then regenerated by heat treatment. You can also do that.

The present invention will be explained below with reference to Examples.

The flask of Reference Example 21 was charged with 5609 g of water, 156.9° sodium chloride, 240 g of a 1.8% aqueous solution of hydroxyethyl cellulose, 5.9 g of a 1% aqueous solution of polyvinyl alcohol, and 2.96 g of sodium nitrite.

To this, 4-vinylpyridine 204.1. ? , divinylbenzene (approx. 50% purity) 136g, isooctane 59.
5 g 1 lauroyl peroxide 3.4 g and benzoyl peroxide 2. A liquid solution consisting of Og is added.

Without stirring, raise the internal temperature to 95°C, and keep it at that temperature for 8
Keep time.

After cooling, the solid is separated in a furnace, washed with water, methanol, and dried to obtain white beads of macroporous poly-4-vinylpyridine.

Example 1 10 parts of beads of poly-4-vinylpyridine having a particle size of 32 to 48 mesh prepared according to the reference example were mixed with 4 parts of poly-4-vinylpyridine beads of copper formate.
10 parts of water salt (Cu(OCCH)2.4H20) and 1 part of formic acid
0 part was dissolved in 100 parts of water, added to the prepared aqueous solution, and stirred at room temperature for 10 hours.

The solid was separated in a furnace, washed with water, washed with methanol, and dried to obtain a blue polymer complex compound.

As a result of analysis, this material contained 9% by weight of copper.

Next, 300 CC (170 g) of this polymer complex compound was filled into a glass tube with an inner diameter of 25 mm, and heated and decomposed at 150° C. for 1 hour under reduced pressure.

After cooling to room temperature, water saturated with oxygen in air (containing about 9 ppm oxygen) was passed through at a flow rate of 1.51 per hour.

When the oxygen concentration of the treatment liquid was measured, no oxygen was detected.

Although 2001 waters were continuously treated, no oxygen was detected in the treated liquid even at the final point.

Further, when the copper content in the treatment solution was measured, no copper was detected.

Example 2 The same operation as in Example 1 was performed except that methanol saturated with oxygen in air was used instead of water.
No oxygen was detected in the treatment solution.

Example 3 The same operation as in Example 1 was performed except that acrylonitrile saturated with oxygen in air was passed at a flow rate of 100 rIll/hour instead of water, and no oxygen was detected in the treated liquid.

Example 4 When the same operation as in Example 1 was performed except that nitrogen gas containing 0.1% oxygen was passed at a flow rate of 31% per hour instead of water, no oxygen was detected in the passing gas. Ta.

Example 5 10 parts of poly-4-vinylpyridine having a particle size of 32 to 48 mesh prepared according to the reference example was mixed with cupric chloride dihydrate (
It was added to an aqueous solution prepared by dissolving 12.2H20) parts of CuC in 100 parts of water, and the mixture was stirred at room temperature for 10 hours.

The solid was separated in a furnace, washed with water, methanol, and dried to obtain a blue polymer complex compound.

Next, this polymer complex compound 2 Qcc (11.5 g) and 100 cc of water were placed in a 200 CC flask, 3 g of sodium borohydride was added while nitrogen gas was passed through the flask, and the mixture was stirred at room temperature for 5 hours.

The thus obtained copper-containing resin was filled into a glass tube with an inner diameter of 10 mm so as not to be exposed to air, and thoroughly washed with deaerated water.

After that, 50 TLl of water saturated with oxygen in the air is added per hour.
No oxygen was detected in the treatment liquid when it was passed through the treatment liquid at a flow rate of .

Claims (1)

[Claims] 1. A method for removing trace amounts of oxygen in a fluid, which comprises bringing a fluid into contact with a copper-containing resin obtained by reducing a polymer complex compound of a polymer compound containing a pyridine skeleton in its structure and a copper salt. .