JPS6084194A - Treatment or recovery of alkali hydrosulfide solution - Google Patents

Abstract

PURPOSE:To obtain an alkali hydrosulfide solution having no bad odor by the extractive removal of a minute amount of the acidic oil component dissolved therein, by adding and dispersing a hardly water soluble or insoluble solvent in the alkali hydrosulfide solution formed in a petroleum factory. CONSTITUTION:A hardly water soluble or insoluble solvent such as ketone, alcohol, ether or ester or a solvent mixture thereof is added to the alkali hydrosulfide solution or the reaction system of the alkali hydrosulfide solution formed in a petroleum relating factory. This solvent is dispersed throughout the solution to be treated by a stirring means to perform the extractive removal of a munite amount of the acidic oil component dissolved in the alkali hydrosulfide solution. By this method, not only mercaptans but also thioethers can be removed almost perfectly as well as COD of evaporated drain generated in a concn. process can be almost all removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating or recovering an alkaline hydrosulfide solution produced in a petroleum-related factory or by adding a solvent to an alkali hydrosulfide solution or its production reaction system to extract and remove dissolved acidic oil. be.

Cracking gas and fuel gas at oil-related factories.

Alkali-soluble acidic oil coexists in waste gas, soot, kerosene, and diesel oil, and is dissolved in alkaline liquid when washed with alkaline liquid for the purpose of desulfurization, deoxidation, purification, etc. Therefore, since such alkaline cleaning waste liquid contains a large amount of acidic oil dissolved therein, it is difficult not only to utilize it, but also to treat pollution, and it is generally treated by a neutralization method. However, this method not only requires a large amount of chemical solution for neutralization, but also generates acidic gases such as H2S during the neutralization process, and also generates bad odors caused by mercaptans. , tertiary treatment is now indispensable, and those involved are struggling because the treatment process is complex and requires a large amount of cost.

Under these circumstances, it is known to those concerned that the numerous technologies developed by the present inventors for producing alkaline hydrosulfide liquid from alkaline waste liquid and H, S-containing gas, etc. have been put into practical use and are proving effective. This is something that I am very familiar with. (Patent No. 4
No. 01527.

Same No. 404799, Same No. WJ417114, Same No. 41
(See No. 8472, No. 800401, No. 900772) However, in the alkaline hydrosulfide solution produced by these methods, there is a trace amount of acidic oil dissolved in the alkaline hydrosulfide solution that is separated and removed in the production process (because the bath dissolution limit is not exceeded). Although the composition of the trace amount of acidic oil dissolved in the alkali hydrosulfide solution varies depending on the alkaline waste liquid that produces the alkali hydrosulfide solution and H2S-containing scum, phenols, thiophenols, mercaptans, etc. (i or two or more types are included, causing a bad odor.

Therefore, the present inventors have developed an extraction method using petroleum fractions such as kerosene and their refined fractions, and Φ or these extracted fractions as a countermeasure and treatment method for the bad odor of alkaline hydrosulfide liquid containing a trace amount of acidic oil dissolved in it. We have developed a method to remove foul-smelling acidic oil by adding activated carbon to the oil, and it has been effective. (See Patent No. 638775.) However, in this method, although mercaptans can be easily removed, acidic oils such as phenols and thiophenols that have relatively high solubility in water or are highly acidic still remain hydrosulfurized. These alkaline hydrosulfides may remain in the alkaline solution.Although the odor from the acidic oil is slight, they remain in the alkaline solution.If this method is used to remove phenols and thiophenols from the alkali hydrosulfide solution, In order to remove it almost completely, an extremely large amount of extracted fractions such as petroleum fractions and their refined fractions (several tens of times more than the amount of alkaline hydrosulfide solution) is required, and these fractions and activated carbon must coexist. In the case of treatment, although the effect of removing acidic oil components is improved, activated carbon adsorbs a large amount of these fractions, making the regeneration process complicated (increasing regeneration costs).

When this alkali hydrosulfide solution containing a small amount of dissolved acidic oil is concentrated and made into a product (alkali hydrosulfide solution approximately 70 wt%), the acidic oil transfers to the evaporation drain during the concentration process, and even if dissolved H and S are removed, In addition, since the drain has a high 00D, pollution treatment using Na0tO, oxygen, etc. is essential, but this pollution treatment requires a large amount of chemicals and significantly complicates the treatment and operation steps.

Under these circumstances, the present inventors searched for extraction solvents that can effectively remove 7 enols and thiophenols from alkali hydrosulfide solution, and as a result of various experimental studies, we found that It has been discovered that a solvent consisting of 1a or two or more of ether-based and ester-based solvents has a remarkable effect on removing acidic oil compared to petroleum fractions and their 4W'Jll fractions. We have also discovered that by adding one or more of these solvents to the reaction system for producing alkaline hydrosulfide, it is possible to recover alkaline hydrosulfide with almost no acidic oil dissolved therein.

That is, the present inventors have used isobutyl methyl ketone and butyl methyl ketone as ketone bath agents that are sparingly f8 or insoluble in water and stable against alkalis for hydrosulfurized alkaline liquid or its production reaction system.

2 as an alcohol-based solvent such as methylglovirkedone.
- Ethylhexanol, n-octatool, n-heptatool, etc., dibutyl ether as an ether solvent,
After adding one or more solvents such as inglovir ether, n-butyl acetate, +, +, +-) dichloroethane (in a broad sense, ester type λ) as an ester solvent, use an appropriate method such as stirring or shaking. By dispersing and extracting in the treatment liquid, acidic oils including mercaptans, phenols, and thiophenols can be removed very easily, and the bad odor caused by acidic oils can also be removed. It was discovered that the COD of evaporative condensate generated as alkali liquid is concentrated can be significantly reduced.

It has also been confirmed that when extracting and removing only mercaptans using these solvents, the amount used in the case of petroleum fractions and their FF# fractions can be sufficiently removed.

Next, the present inventors investigated the treatment or recovery conditions for the alkaline hydrosulfide solution using the bath agent as described above, and found that the proportion of alkali sulfide is high (the pH of the alkali hydrosulfide solution or its production reaction system is Although there is a tendency for the removal effect of acidic oil to decrease with high V), if the alkali sulfide content is less than 7 mole, preferably less than 5.5 mole relative to the alkali hydrosulfide, the concentration of alkali hydrosulfide will not be affected and the temperature will be kept at room temperature. It was confirmed that it could be removed effectively. Note that the amount of extraction solvent to be added can be estimated based on the desired removal rate if the concentration of acidic oil is known. If the amount is too small relative to the amount of processing liquid, the contact efficiency will decrease and stirring, Since dispersion operations such as shaking are required for a long time, it has been confirmed that it is preferable to set the volume to at least 2 times the amount of processing liquid.

In addition, it was confirmed that the solvent used to extract acidic oil can be easily regenerated with caustic alkaline solution by a conventional method, and can be reused for acidic oil extraction. It was also confirmed that the pH of the caustic alkaline solution used for regenerating the solvent used is preferably at least 12 or higher, and that the acidic oil can be concentrated in a very high concentration in the regenerating solution with a small amount if it is concentrated.

Furthermore, the present inventors have found that when these solvents are used in the hydrosulfide alkali solution or the production reaction system, and the condensate generated when the treated or recovered alkali hydrosulfide solution is concentrated, there is still a slight amount of CO.
As the phenomenon of increasing D was observed, we investigated the cause and arrived at the idea that the solvent used in the present invention dissolves in a very small amount in the hydrosulfide alkali solution during treatment or recovery. In order to suppress and prevent the contamination of solvents, we conducted various experiments and found that the treatment or recovery operation of alkali hydrosulfide solutions was carried out with a concentration of 2 to 50 volumes of chlorotic, alcohol-based, ether-free, and ester-based solvents. Water-insoluble solvents (hereinafter referred to as
By using these solvents (referred to as "insoluble solvents"), it is possible to suppress or prevent a trace amount of the solvent from dissolving in the alkali hydrosulfide solution without impairing the acidic oil removal effect, and to evaporate when the alkali hydrosulfide solution is concentrated. It was confirmed that most of the 00D in the drain could be removed. Furthermore, the effect of preventing solvent contamination was also observed by re-treating the alkaline hydrosulfide solution, which had been treated or recovered using a ketone, alcohol, ether, or ester solvent, with an insoluble solvent.

That is, the present inventors added one or more of ketone, alcohol, ether, and ester solvents that are poorly soluble or insoluble in water to the alkaline hydrosulfide solution or its production reaction system produced in petroleum-related factories. Mercaptuffs, phenols, and thiols can be extracted by adding a bath agent or a mixed bath agent of these solvents and an insoluble solvent, and dispersing it in the treatment liquid using stirring, shaking, or other methods. It was confirmed that because phenols can be almost completely removed, an alkaline hydrosulfide solution free of bad odors caused by acidic oil can be obtained, and that most of the COD from evaporative condensate generated during the cotton-making process can be removed.

hJi-H+n BE14F et W-4 Go 5CLR day Jr. jd+rljl: 3hT÷QIy to the hydrosulfurized alkaline solution or its production reaction system as an extraction solvent for acidic oil, a ketone type that is sparingly soluble or insoluble in water. , a solvent consisting of one or more of alcohol, ether, and ester solvents, or a mixed solvent of these solvents and other insoluble bath agents. This is an economical method for treating or recovering a hydrosulfurized alkali solution, which makes it possible to easily remove acidic oils, including phenols and thiophenols, which are difficult to remove using conventional methods.

Next, the method of the present invention will be specifically explained using examples to make it clearer.

Example 1 1 ton of Nr-8H solution produced in an oil refinery and having the composition and properties shown in 1 and the ketone solvent isobutyl used as an extraction solvent to remove the acidic oil in the NaBH solution. 80 ml of methyl ketone was placed in a 2 t flask equipped with a stirring device, stirred for 5 minutes, and then the solvent was separated by a standing method to obtain a treatment liquid containing almost no acidic oil as shown in Table 2.

Note that this treated liquid also had odor caused by acidic oil removed, and the COD of the drain generated by concentration was low.

Furthermore, the isobutyl methyl ketone used here, which was regenerated using a standard caustic alkaline solution, was suitable for repeated use for the extraction of acidic oils.

Table 1 Nail (fi, composition, properties Na5H26, 80wt% Na2S 2.01s Na2co31.00 # Ha2BO3 (1,65# Na2S2O30, 20'tr Acidic oil content 450 ppm COD of drain Note) 10/+ [I ITNa2F3/
Na5H (5,59 moles) Table 2 Composition and properties of treatment liquid Na5H26,79 wt% Na18 2.02, r Na200g 0.99 # Na2803 0.65 x Na2S203 [1201 Acidic oil content 15 ppm COD of drain 38 # Note) Dissolved H and S are removed from the evaporation drain generated when the masH solution is concentrated to 70 wt%.

Example 2 A Na5H solution produced in a petrochemical factory and having the composition and properties shown in Table 3 was treated using the same equipment as in Example 1.
Adding 1 t of a5H liquid and 60 g of 2-ethylhexanol, an alcoholic solvent, as an acidic oil extracting solvent, the same operations and methods as in Example 1 were carried out to obtain a treatment containing almost no acidic oil as shown in Table 4. Liquid 75 (obtained).

This treatment solution was the same as in the previous example (it was able to remove the bad odor of fleas (75%), and the COD of the tren was also small due to concentration).

Table 5 Composition and properties of NaBH liquid Na5H22, 50wt'% Na2S 1.52y Na2C! 03 i, 40 p Na2So30.46 # Na2S2O5O, + 2 # Acidic oil content 96 ppm Na2S / Naf9H (4,25 mortise) Composition of treatment liquid, properties Na5H22,3+ wt% Na2S'.!+2 p Na, Co, 1 .40 # Na2SO30, 45N Na2S2O30, + 1 1 Example 6 A Na5H solution with the composition and properties shown in Table 5, which was produced in a petroleum N factory, was treated with 1 t of NaEIH solution using the same equipment and method as in Example 1. 1,301 nt of diptyle ether, an ether bath agent, was used as the acidic oil extraction solvent, and a treatment liquid containing almost no acidic oil as shown in Table 6 was obtained.

Similar to Examples 1 and 2, this treatment liquid was able to remove bad odors, and the COD of the drain due to concentration was also low.

Table j Composition and properties of Na5H liquid NaE3H25,59wt% Na, 8 1.181 Na2GO30,921 ua, 5o30.55 # NaxSz"s O, 52# Acidic oil content 295 Ppm NazS/Na5H (&5S mole).

Table 6 Composition and properties of treatment liquid Na5H25,6Q *t% Na, 8 1.19 # Na2co30.901 Na2So, 0.551 Na2S203 o, 30 N Acidic oil 2 ppm Example 4 Composition used in Example 2, The Na5H solution 11 having the same properties was treated using the same equipment and method as in Example 1, using the ester solvent n-butyl 60-acetate as the acidic oil extracting solvent, and a treated solution equivalent to that in Example 2 was obtained. The same effect as in Example 1 was observed.

Example 5 1 t of Na5H solution having the composition and properties used in Example 6 was treated using the same equipment and 2 methods as in Example 1 using a mixed solvent of isobutyl methyl ketone 4Ω and 2-ethylhexanol 40 ml as the acidic oil extraction solvent. A treatment solution equivalent to that of Example 3 was obtained using the same method as in Example 3, and the same effects as in Example 1 were observed.

Example 6 1 ton of Na5H solution having the composition and properties used in Example 1 was treated using the same equipment and method as in Example 1, using 8° of isobutyl methyl ketone as the acidic oil extraction solvent and 50° of n-hexane as the insoluble bath agent. (7) Performed using a mixed solvent, Table 7V
A treatment solution containing almost no acidic oil as shown in C was obtained.

This treatment liquid was able to remove bad odors as in Examples 1 to 5, and the COD of the drain was significantly reduced due to the effect of n-hexane.

Table 7 Composition and properties of Na5H liquid Na5H26, 79wt% Na, 8 2.00 1 Na2co31.02 #Ha2Sos' 0.67 N Na2B2030.20 1 Acidic oil 3 ppm7 Drain I:! OD /, Example 7 1 ton of Na5H solution with the composition and properties used in Example 1 was treated using the same equipment and method as in Example 1, and the 15th regeneration of isobutyl methyl ketone with caustic alkaline solution was used as an acidic oil extraction bath agent. A treatment solution equivalent to that in Example 6 was obtained by using a mixed solvent with -150% hexane, and the bad odor was also removed in the same manner as in Examples 1 to 6.

Example 8 0.85 t of alkaline waste liquid discharged from a 1 t'r petroleum factory and having the composition and properties shown in Table 8, 200 m of inbutyl methyl ketone as an extraction bath agent for acidic oil, and n-hexane as an insoluble bath agent. 550- is placed in a 2t three-bottle flask equipped with a stirrer, a gas inlet, and an outlet for unreacted gas, and while operating the stirrer, H2S gas is introduced from the gas inlet until the NazS content is approximately 2 compared to the NaSH content.
After absorbing the solution into molar strips to generate a NaSH 2 solution, the bath agent was separated by a standing method, and a NaSH 2 solution containing almost no acidic oil as shown in Table 9 was recovered.

In addition, this recovered liquid was able to remove the bad odor caused by acidic oil, and the COD of the drain obtained by concentrating the recovered liquid was also low.

Table 8 Composition and properties of alkaline waste liquid NaOH, +5.90 wt% Na2S 5.60 N Acidic oil 6400 ppm Table 9 Composition and properties of recovered liquid NaSH 2 5,20 wt% Na2S O. 75 # Na2003 0.89 1 Na2SOs O. I 2 N Na2S203 θ. 08I Acidic oil content 5 ppm Drain COD6I Na,s/NaSH (21) 8 mol%) Example 9 In Example 8, only isobutyl methyl ketone 220d was used as the extraction solvent, and the rest was carried out in the same manner as in Example 8. However, a Na5H solution as shown in Table 10 was recovered.

Table 10 Composition and properties of recovered liquid Na5H25,07wt% Na2S 0g2# Na2CO30,891 Na2SO30,+ Or Na2S203 0.07'1 Acidic oil content 5 ppm These examples are merely examples for specifically explaining the present invention. Of course, it includes many elements of modification and improvement within limits, and does not limit the technical 2M idea of the present invention.

As explained above, the present invention is directed to a hydrosulfurized alkali solution produced in a petroleum-related factory or a ketone system that is sparingly soluble or insoluble in water to the production reaction system thereof.

An alkali hydrosulfide characterized by extracting and removing acidic oil by adding a solvent consisting of one or more alcohol-based, ether-based, or ester-based M agents, or a mixed solvent of these solvents and other insoluble solvents. It is a method of processing or recovering liquid.

By implementing the method of the present invention, the following effects can be expected.

■ A high-grade alkaline hydrosulfide solution with almost no dissolved acidic oil can be obtained, and the quality of the concentrated product is significantly improved.

■ Since it is possible to obtain an alkaline hydrosulfide solution that does not have a bad odor due to acidic oil, it is possible to prevent environmental pollution due to bad odor, which is useful for preventing pollution, and has a remarkable social effect.

■ In the process of concentrating alkaline hydrosulfide, the COD of the evaporated condensate generated is significantly reduced, which not only simplifies the pollution equipment required for condensate treatment but also significantly reduces operating costs, which has no social or economic effects. It's a huge amount.

■ Conventional separate document processing equipment can be reused and no special processing equipment is required, further increasing the economic effect.

Among agents: 1) Akira Agent Ryo Hagi Hara -

Claims (1)

[Claims] (1) One or more types of a-bath or insoluble ketone-based, alcohol-based, ether-based, and ester-based solvents are added to the production reaction system of alkaline hydrosulfide or alkaline hydrosulfide generated in petroleum-related factories. or a mixed solvent of these solvents and a water-insoluble solvent is added and dispersed in the treatment solution to extract and remove trace amounts of acidic oil dissolved in the alkaline hydrosulfide solution. A method for treating or recovering an alkali hydrosulfide solution having 4f-characteristics.