JP2002177960A - Ammonia treatment method for brine incidental to natural gas after iodine collection work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which is capable of efficiently treating the ammonia in brine incidental to natural gas by using a method of electrodialysis. SOLUTION: The ammonia in the brine incidental to the natural gas after iodine collection work is treated by a process step of removing undissolved matter from the brine incidental to the natural gas after the iodine collection work, a process step of concentrating the dissolved matter containing the ammonia in the brine incidental to the natural gas removed of the undissolved matter by the electrodialysis using an ion exchange membrane and a process step of underground reducing the condensate of the dissolved matter containing the ammonia.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating ammonia with natural gas accompanying irrigation after iodine sampling, and more particularly, to efficiently and inexpensively removing ammonia, one of the regulated substances, from natural gas accompanying brine after iodine sampling. On how to handle.

[0002]

2. Description of the Related Art Iodine is contained abundantly in natural gas accompanying brine buried in the ground, and is industrially mainly produced and extracted by an expulsion method. This mixes chlorine gas with natural gas accompanying brine pumped from underground,
The iodine is oxidized and liberated, and air is sent from the bottom of the tower containing the brine, the iodine is expelled from the liquid, the inside of the tower is moved to the absorption liquid side by air, and sodium hydrogen sulfite is added to this, and reduced. Then, iodine is dissolved in the absorbing solution, and the absorbing solution with the increased iodine ion concentration is sent to the next step to produce iodine.This method extracts iodine from a huge amount of natural gas accompanying brine. This is the best method.

[0003] On the other hand, natural water accompanying natural gas after iodine has been collected is usually discharged directly to the ocean without any special treatment. However, the irrigation water after iodine collection contains a small amount of ammonia. From the viewpoint of preventing eutrophication of the ocean, the release of this ammonia-containing brine into the ocean is being regulated as undesirable. In addition,
This regulatory movement is based on the hypothesis or concern that ammonia is decomposed into nitrogen in the sea by the action of marine microorganisms and the ocean is eutrophic by nitrogen oxides.

[0004]

As a method for treating ammonia dissolved in water, there are a zeolite adsorption method, a reverse osmosis method, a stripping method, and the like. When applying to the treatment of ammonia, there is a problem that the treatment capacity is reduced in the reverse osmosis method and the zeolite adsorption method because the salt coexisting in the brine has a high concentration. On the other hand, in the stripping method, a large amount of chemicals such as an alkali adjuster and a neutralizing agent for adjusting the pH must be used, which is extremely inferior in economical efficiency.

Further, there is an activated sludge method as a method for decomposing ammonia. However, this method requires a long time for treatment, requires a constant temperature, and requires an enormous amount of heat. Required a large area for installation. In addition, an enormous amount of sludge is generated, and its disposal requires enormous costs.

[0006] If the treatment of ammonia is carried out by these methods and the treatment cost is passed on to the production cost of iodine, it is inevitable that the price of iodine as a product will jump several times. It was impossible to adopt these methods at all. Therefore, either of these methods
It was unsuitable for treating ammonia with natural gas-associated brine in the iodine production process, which would handle huge quantities.

[0007] The present inventor has conducted intensive studies on a method for efficiently and inexpensively treating the enormous amount of ammonia generated in the iodine-producing process with ammonia in the brine accompanying natural gas. A method for efficiently treating ammonia in the natural gas-associated brine using an electrodialysis method that has not been used has been established, and is proposed herein as the present invention.

[0008]

[Means for Solving the Problems] A step of removing insolubles from the natural gas accompanying brine after the iodine sampling operation, and using an ion exchange membrane for the dissolved matter containing ammonia in the natural gas accompanying brine with the insolubles removed. The step of concentrating by electrodialysis and the step of underground reduction of a solution concentrate containing ammonia are used to treat ammonia in the brine supplied with natural gas.

FIG. 1 is a block diagram of a treatment plant used in the method for treating ammonia with natural gas accompanying brine after an iodine sampling operation according to the present invention.

In the figure, 1 is an insoluble material removal tank, 2 is a de-insoluble material liquid tank, 3 is a dissolved substance concentration chamber, 4 is a de-dissolved substance chamber, 5 is a dissolved substance concentrated liquid tank, and 9 is a treated water storage tank. In addition, the lysate concentration chamber 3 and the delysate chamber 4 are formed in an electrodialysis tank 10.

After the iodine has been collected by the flushing method or the like, the brine attached to the natural gas is sent to the insoluble matter removal tank 1.

[0012] Natural water accompanying brine contains insolubles such as organic decomposed products. In the insolubles removal tank 1, the insolubles are removed by a sand filter or the like. Thereafter, the de-insoluble material liquid is once stored in the de-insoluble material liquid tank 2 and then sent to the electrodialysis tank 10.

As shown in FIG. 2, the electrodialysis tank 10 includes a plurality of strong acid cation exchange membranes 11 and strong basic anion exchange membranes 12 arranged alternately, and a plurality of lysate concentrating chambers 3 and desolubilizing chambers 4. Are alternately formed, and a pair of plus electrodes 13 and minus electrodes 14 are disposed at both ends thereof. A DC voltage is applied between the two electrodes 13 and 14 to ionize the ionized cations and anions every other room. The formed product accumulates in the dissolved material concentrating chamber 3 and concentrates the dissolved material in the brine with natural gas. The lysate is iodine, ammonia, sodium,
Calcium, magnesium and the like.

That is, in the electrodialysis tank 10,
In the dissolving chamber 4 in which the strongly basic anion exchange membrane 12 is present on the plus electrode 13 side and the strongly acidic cation exchange membrane 11 is present on the minus electrode 14 side, the ionized cations move toward the minus electrode 14 side, and the strong acid After passing through the neutral cation exchange membrane 11 and reaching the adjacent lysate concentration chamber 3, the passage through the next strongly basic anion exchange membrane 12 is prevented, but the anions move toward the plus electrode 13 in the opposite direction, The permeate through the basic anion exchange membrane 12 to the adjacent lysate concentration chamber 3,
The next strong acid cation exchange membrane 11 blocks the passage. Therefore, ionized dissolved substances such as ammonia are accumulated in the alternately formed dissolved substance concentrating chamber 3, and as a result, the dissolved substances in the natural gas accompanying brine are concentrated.

Since the material of the exchange membrane of the electrodialysis tank 10 has an amine group, there is a concern that it may be bonded to iodine ions. However, the irrigation with the natural gas accompanying the natural gas sent to the electrodialysis tank 10 is carried out by a purge method or the like. It is intended the after, the iodine concentration for a not only about 10 ppm, no effect on the exchange membrane, IO ₃ to about 100 ppm ^- is concentrated in the lysate concentrate in our state.

The lysate concentrate chamber 3 of the electrodialysis tank 10 is connected to a lysate concentrate tank 5, and the lysate concentrate concentrated in the lysate concentrate chamber 3 is temporarily stored in the lysate concentrate tank 5. Is stored. In this electrodialysis tank 10, the ammonia concentration in the iodine-containing brine is concentrated about 10 to 15 times, and the liquid volume is reduced to about 1/20.

The dissolved liquid concentrate containing ammonia once accumulated in the liquid concentrated liquid tank 5 is first sent into the ground where natural water accompanying brine is pumped, and is reduced underground.

Since the concentrated solution of the lysate concentrated by the electrodialysis tank 10 was originally contained in the brine accompanying natural gas pumped from underground, there is no problem if it is directly reduced to underground.

On the other hand, the de-dissolved liquid accumulated in the de-dissolved substance chamber 4 of the electrodialysis apparatus 10 is temporarily stored in the treated water storage tank 9 and then discharged to the ocean.

[0020] Since this de-dissolved liquid contains almost no ammonia, there is no problem even if it is discharged into the ocean. Alternatively, a part of the de-dissolved liquid may be reduced to the underground.

[0021]

EXAMPLE An ammonia concentration of 240 ppm after iodine sampling by a stripping tower, and NaCl as another dissolved substance component
31900 ppm, Ca ion 0.24 ppm, M
g ion 0.50 ppm, SO ₄ ^2- Ion 0.2
Brine with natural gas containing 5 ppm and 10 ppm of I ^- ion was passed through a filter to remove insolubles. The degree of removal is FI (fouling index) ≤
And 4. After the iodine collection work from which the insoluble matter was removed, the brine attached with natural gas was sequentially passed through an electrodialysis apparatus to perform electrodialysis treatment. Electrodialysis was carried out at a liquid temperature of about 30 ° C. using Pt as an electrode by alternately combining a strongly basic anion exchange membrane and a strongly acidic cation exchange membrane. The ammonia concentration of the de-lysate obtained by electrodialysis is 100 pp
m, which is much lower than what is considered a drainage standard. Further, other dissolved components were NaCl 19400 pp.
m, Ca ion 20ppm, Mg ion 150pp
m, SO ₄ ^2- The ion became 230 ppm. On the other hand, the ammonia concentration of the concentrate was 2580 ppm.
The dissolved component is NaCl 240,000 ppm, Ca
Ion 3900ppm, Mg ion 6300ppm,
SO ₄ ^2- Ion 500ppm, I ^- ion 60
ppm. This lysate concentrate is a mere concentration of the lysed components in the brine with natural gas, and has no other contaminants. It was confirmed that there was no problem in mixing a part of the de-lysate solution with this concentrate and diluting the diluted concentrate to the underground.

[0022]

The ammonia treatment method for natural gas accompanying brine according to the present invention has the configuration as described above. After the iodine is collected by an existing method, the natural gas accompanying brine is concentrated by electrodialysis to remove ammonia. It is designed to reduce the concentration of dissolved solution containing water underground, and it is economically possible to process wastewater containing ammonia in accordance with the regulations for ocean discharge, and from the viewpoints of global environmental protection and effective use of underground resources. Extremely practical.

[Brief description of the drawings]

FIG. 1 is a block diagram of a plant used for an ammonia treatment method for watering accompanying natural gas after iodine collection according to the present invention.

FIG. 2 is an explanatory view of an electrodialysis tank used in the ammonia treatment method for brine with natural gas after iodine collection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insoluble matter removal tank 2 De-insoluble substance liquid tank 3 Dissolved substance concentration chamber 4 De-dissolved substance chamber 5 Dissolved substance concentrated liquid tank 9 Treatment water storage tank 10 Electrodialyzer 11 Strongly acidic cation exchange membrane 12 Strongly basic anion exchange membrane 13 plus electrode 14 minus electrode

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA18 HA47 JA41A JA42A JA42C JA43A JA44A KA01 KA31 KA64 KB15 MA03 MA13 MA14 MB07 PA01 PB08 PB28 PC80 4D061 DA08 DB18 EA09 EB01 EB04 EB13 EB19 EB30 FA13 FA17

Claims (4)

[Claims] Claims: 1. A step of removing insolubles from natural gas accompanying brine after an iodine sampling operation, and a step of subjecting a dissolved substance containing ammonia in the natural gas accompanying brine from which insolubles have been removed to electrodialysis using an ion exchange membrane. A method for treating ammonia with natural gas accompanying brine after an iodine collection operation, comprising: a step of concentrating; and a step of underground reducing a dissolved concentrate containing ammonia. 2. The method of claim 1, wherein the concentration of iodine in the natural gas-associated brine that is electrodialyzed by the ion exchange membrane is about 10 ppm. 3. The concentration of ammonia in natural water accompanying brine is concentrated 10 to 15 times by electrodialysis, and the liquid volume is reduced to 1/15.
2. The method of claim 1, wherein the water is reduced to about 20. 4. The method of claim 1, wherein the de-lysate separated by electrodialysis is discharged directly into the ocean current.