KR101691953B1 - Method of Removing Organic Acid from Acidic Crude Oil or Hydrocarbons - Google Patents

Abstract

The method for removing organic acids from high acidity crude oil or hydrocarbon oil according to the present invention comprises extracting organic acids from a high acidity crude oil or a hydrocarbon oil into a diol compound using a diol compound having a liquid-liquid phase equilibrium with a high acidity crude oil or a hydrocarbon oil, It is possible to effectively remove organic acids from crude oils and hydrocarbon oils having high acidity by removing organic acids from crude oil or hydrocarbon oil fractions and to remove impurities and emulsions generated by removing organic acids and to recover the additives, This is possible.

Description

TECHNICAL FIELD The present invention relates to a method for removing organic acids from crude oil or hydrocarbon oil,

The present invention relates to a method for removing organic acids from high acidity crude oil or hydrocarbon oil, and more particularly, to a method for removing organic acids from high acidity crude oil or hydrocarbon oil using a diol compound having a liquid-liquid phase equilibrium with crude oil or hydrocarbon oil. To a method for removing organic acids from high acidity crude oil or hydrocarbon oil fractions.

Generally crude crude oil is called opportunity crude because it is very different from general crude oil and its components and properties are called mining crude oil. For example, in Africa, Sudanese Opportunity crude is called Dar Blend, and Chad Mountain Opportunity crude is called Doba Blend. Diversity and Toba Blend have almost similar properties.

The organic acid content in the crude oil is mainly in the form of naphthenic acid (NA), and is used to produce crude oil (Doba) in West Africa such as Chad, Brent crude oil (Griffon), Canadian crude oil (Shin Crud) The oil of high pH is produced compared to the existing crude oil.

This high acidity of crude oil causes corrosion and equipment failure in crude oil processing, storage facilities and distillation process, which causes the product quality to be lowered. The problem of corrosion requires replacing the existing crude oil treatment facility, and the metal compounds produced by the corrosion cause a solid blockage in the pipeline.

Since naphthenic acid has a cyclopentane structure and is a high molecular weight carboxylic acid, it has difficulties in determining the physical properties and treatment methods of naphthenic acid because it has various properties depending on the region where crude oil is produced. For this reason, crude oil with a high acidity is treated as low-grade crude oil, which is traded at a lower price than crude oil with low acidity, and the technology of removing organic acids from high-grade crude oil is attracting attention.

The most widely used method of indicating the concentration of organic acids in crude oil is TAN (total acid number, mg KOH / g), which is the milligram of calcium hydroxide (KOH) required to titrate 1 gram of crude oil. ISO 6619, KS M ISO 6618. In general, the TAN value of crude oil is lowered through the treatment of organic acids in crude oil, and crude oil of TAN 1 or more in general can be said to be corrosive.

Conventional techniques use a method of lowering the acidity of crude oil by neutralizing naphthenic acid in crude oil or using alcohol and converting the carboxylic acid functional group with a catalyst using a basic material to lower the acid value of crude oil .

Korean Patent Registration No. 10-1040966 discloses a reaction in which an alkaline earth metal cation or a transition metal cation is combined with an anion such as silicate or aluminate to lower the acidity by a decarboxylation reaction of an organic acid. A high reaction temperature (250 ° C) is required to remove acids using chemical reactions, and there is a naphthenate impurity problem caused by the reaction of the metal catalyst with naphthenic acid.

European Patent No. 1066360B1 discloses a method of extracting naphthenic acid into an aqueous phase using an alkyloxyamine having a high molecular weight, but an emulsion is formed by separation into an aqueous phase, and the resultant amine-naphthenic acid is an oil phase There is a problem of remaining as an impurity.

U.S. Patent No. 5,910,242 discloses a method of converting naphthenic acid present in an oil phase to hydrocarbons by hydrotreating. It is necessary to provide a facility for satisfying the reaction conditions that the reaction temperature is 200 to 370 ° C and the reaction pressure is 273 to 13900 kPa.

U.S. Published Patent Application 20060054538 A1 discloses a method for neutralizing an organic acid on a hydrocarbon oil phase using an alkaline earth metal and an ammonium hydroxide salt. However, it has a problem that the formed emulsion can not be completely removed.

U.S. Patent No. 2769768 discloses a method for removing naphthenic acid present in an oil phase using a low molecular weight alcohol and ammonia. However, the extraction efficiency of the acid is 66%, which shows low extraction efficiency.

U.S. Patent No. 2808431 discloses that naphthenic acid present in an oil phase is removed using an extractant using methanol, propanol, water, and ammonia, but a naphthenic salt is formed in the oil phase and there is a problem that an emulsion is formed on the oil phase do.

U.S. Patent No. 4634519 extracts were prepared by using methanol, water, and ammonia to produce extractives of specific composition, and naphthenic acid was obtained through distillation. However, since the extractant contains water, it has a problem of forming an emulsion on the oil.

As described above, in order to lower the acidity of crude oils and hydrocarbon oils having a high acidity, many of the documents such as patents and publications use carboxylic acid functional groups possessed by naphthenic acid and neutralize or decompose naphthenic acid in crude oil with a basic substance To lower the acidity of the crude oil through the treatment of carboxylic acid functional groups or mixing with lower crude oil.

In the method using a basic substance, an emulsion which is difficult to remove after the treatment is formed in the crude oil, and the naphthenate formed by the combination of the basic substance and the acidic substance remains as impurities in the crude oil. In addition, there is a problem with the temperature and pressure for the reaction to occur, and as the reaction is repeated, some catalysts react with the acid component to form naphthenate. There is a disadvantage in that the method of mixing with low-acidity crude oil can not use low-cost crude oil having high acidity.

Accordingly, the present inventors have made intensive efforts to solve the above problems. As a result, the present inventors have found that extraction with a diol compound not only eliminates organic acids from crude oils and hydrocarbon oils having high acidity, but also eliminates impurities and emulsions, It is possible to recover the additive and extract at a low temperature and a low pressure, and the present invention has been completed.

It is an object of the present invention to provide a method for effectively removing organic acids from crude oil and hydrocarbon oil having high acidity, and removing organic acids from crude oil or hydrocarbon oil which are capable of recovering additives without causing impurities and emulsions.

In order to accomplish the above object, the present invention provides a process for producing an organic acid, comprising the steps of: (a) extracting an organic acid by mixing a crude oil or a hydrocarbon oil containing an organic acid with a diol compound; (b) separating the crude oil or hydrocarbon oil and the organic acid-containing diol compound through liquid-liquid phase separation of the mixture; And (c) removing the organic acid from the organic acid-containing diol compound, wherein the organic acid is removed from the crude oil or hydrocarbon oil.

The method of removing organic acids from high acidity crude oil or hydrocarbon oil according to the present invention differs from the conventional method of removing organic acids by mixing a diol compound with a oil classification including an organic acid such as crude oil, The method of extracting organic acids from crude oil and other phases and recycling the diol compound solves the corrosion problem of the apparatus caused by using crude oil having a high organic acid content and the diol compound is recycled, It is possible to solve the problems in use and effectively remove the organic acid. In addition, drilling high alpine oil from oil wells. It is possible to effectively remove the pretreatment process of the crude oil before distillation or the organic acid contained in the hydrocarbon oil fraction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a method for removing organic acids from a high acidity crude oil or a hydrocarbon oil of the present invention.
2 is a graph showing the content of organic acid in crude oil after treatment with hexanediol according to an embodiment of the present invention.
3 is a graph showing the content of organic acids in crude oil after treatment with a diol compound according to an embodiment of the present invention.
Figs. 4 to 6 are photographs showing liquid-liquid equilibrium forms after extraction of diol, water and methanol, respectively.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

In the present invention, not only organic acids can be effectively removed from crude oils and hydrocarbon oils having a high acidity, but also impurities and emulsions generated when organic acids are removed can be recovered, and diol compounds can be recovered, It was confirmed that extraction was possible.

Accordingly, in one aspect, the present invention provides a process for producing an organic acid, comprising: (a) extracting an organic acid by mixing a diol compound with crude oil or hydrocarbon oil containing an organic acid; (b) separating the crude oil or hydrocarbon oil and the organic acid-containing diol compound through liquid-liquid phase separation of the mixture; And (c) removing the organic acid from the organic acid-containing diol compound, and a method for removing the organic acid from the aliphatic crude oil or the hydrocarbon oil fraction.

The present invention relates to a process for efficiently extracting an organic acid component from crude oil and hydrocarbon oil having high acid value and a diol compound such as ethylene glycol, propanediol, butanediol or hexanediol through liquid-liquid phase separation.

The present invention relates to a method for efficiently removing organic acids from hydrocarbon oils containing opportunity crude having high acidity, and the present invention is characterized by using a diol compound. More specifically, the organic acid present in the hydrocarbon oil fraction is extracted with a diol compound according to the affinity, and the diol compound has a liquid-liquid phase equilibrium with the hydrocarbon oil fraction, so that a hydrocarbon oil having a lowered acidity can be obtained by a simple process.

The method for removing organic acids according to the present invention comprises the steps of: 1) extracting an organic acid by mixing a diol compound with a hydrocarbon oil fraction containing an organic acid; 2) separating the hydrocarbon oil fraction and the diol compound through phase separation of the mixture; 3) removing the organic acid from the diol compound containing the organic acid to recycle the diol compound.

In the method for removing organic acids according to the present invention, each of the above steps will be described in detail as follows.

The present invention relates to a process for removing organic acids contained in hydrocarbon oils, which is a crude oil having a high acid value among crude oil, which is a crude oil containing a large amount of impurities, and is capable of effectively removing organic acids have. The process of removing the organic acid according to the present invention is schematically shown in FIG.

1, crude oil or hydrocarbon oil (1) having high acidity and a diol compound are introduced into liquid-liquid extractor (100) to obtain crude oil or hydrocarbon oil fraction (2) having lowered acidity after treatment, The diol compound 3 including the diol compound 3 is recycled to the liquid-liquid extractor 100 after being sent to the solid-liquid extractor 200 and then reduced in the content of the organic acid through crystallization, The organic acid (5) removed from the compound is obtained.

The diol compound in the present invention is a diol compound in which one of ethylene glycol, 1,3-propanediol, 1,3-butadiol, 1,4-butanediol and 1,6-hexanediol or a structural isomer thereof is selected to remove an organic acid Into a hydrocarbon source or crude oil and mix. At this time, the diol compound can be directly introduced into the solid or liquid phase.

In the present invention, the addition amount of the diol compound is 0.1 to 5 times (weight ratio) of the crude oil or hydrocarbon oil, preferably 1 to 2 times. If the amount is less than 0.5 times, the removal efficiency of the organic acid becomes low. If the amount is more than 5 times, the treatment cost and the impurity content in the crude oil may be increased. The acid value of crude oil and hydrocarbon oil may be used when the TAN value is 1 or more and 1 to 5, but it is preferable to use two or more crude oils.

In the present invention, the diol compound is added to crude oil or hydrocarbon oil to perform mixing. Mixing can be carried out by any method between the melting point and the boiling point of each diol compound, preferably at a constant temperature of 60 to 90 DEG C for 10 minutes to 5 hours, preferably 1 hour to 2 hours, The stirring is carried out so that the contact between the oil and the diol compound occurs well. Since the diol compound is viscous, mixing is not likely to occur if the stirring speed is low. Therefore, it is necessary to maintain the stirring speed at 100 to 2000 rpm, preferably at the stirring speed of 500 to 1000 rpm. This process removes organic acids from crude oil and hydrocarbon oils.

After stirring, stirring is stopped so that phase separation occurs so as to cause liquid-liquid phase separation. In this process, the temperature is preferably kept constant at the above-mentioned mixing temperature, and the separation time is preferably maintained for 10 minutes to 2 hours, preferably 30 minutes to 1 hour. If the separation time is insufficient in this process, the diol compound remains as impurities on the separated crude oil and hydrocarbon fractions. Finally, physically separating the separated phases through liquid - liquid phase separation gives crude oils and hydrocarbon fractions with organic acids removed.

Diol compounds including organic acids are obtained through liquid - liquid phase separation, and organic acids can be removed through crystallization of diol compounds. The crystallization proceeds at a temperature below the melting point of the diol compound, preferably at about 10 ° C below the melting point of the diol compound. As the crystallization progresses, the diol compound is present as a solid, and the organic acid is present as a liquid, and thus the organic acid can be easily removed from the diol compound.

Although the above process has been described for the discontinuous process, the diol compound from which the organic acid has been removed can be applied to the continuous process in which the diol compound is recycled in the liquid-liquid phase separation process.

The above process is not greatly affected by the pressure, but it is preferable to proceed at a normal pressure.

Through the above process, a trace amount of water and hydrophilic salts contained in crude oil and hydrocarbon oil can be removed through the hydrophilic diol compound.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are for illustrative purposes only and that the scope of the present invention is not limited by these embodiments.

[Example]

Examples 1 to 4

Experimental hydrocarbon fractions of about TAN 5 were prepared by mixing naphthenic acid (Sigma Aldrich Co.) in diesel (Hyundai Oilbank) and TAN was measured by KS M ISO 6619.

10 g of experimental hydrocarbon oil was injected into a 50 ml glass vial and 5, 10, 15 and 20 g of solid 1,6-butanediol were injected. Thereafter, the temperature was elevated from room temperature to 60 DEG C by using a hot plate, and 1,6-butanediol was present as a liquid phase and stirred at 700 rpm using a stirring magnet. The mixing time was 1 hour.

After completion of the mixing, the stirring is stopped only on the hot plate to cause liquid-liquid phase separation at 60 ° C, and the separation time is set to 30 minutes. When the separation is completed, there are two liquid phases inside the glass vial, and the liquid at the upper end is hydrocarbon oil and the liquid at the lower end is 1,6-butanediol.

One gram of each sample was sampled and the TAN of each phase was measured using a potentiometric titrator according to the KS M ISO 6619 method. The automatic titrator was a G20 instrument manufactured by METTLER TOLEDO, and a suitable electrode was DGi116-Solvent. The results are shown in Table 1 and Fig.

No. 1,6-hexanediol mass ratio The acidity (TAN) Removal rate (%) Example 1 0.3865 2.5801 48.40 Example 2 0.9544 1.4089 71.82 Example 3 1.4267 1.0323 79.35 Example 4 1.9082 0.7599 84.80

As shown in Table 1 and FIG. 2, the acidity of the hydrocarbon oil after the 1,6-hexanediol treatment increased with increasing the mass ratio of 1,6-hexanediol, and the organic acid removal rate was 84.8% when the mass ratio was about 1.9 , Which corresponds to a relatively high organic acid removal rate.

Examples 5 to 8

Experiments were conducted to confirm the removal of organic acids on the hydrocarbon fractions of other diol compounds other than 1,6-hexanediol. In the same manner as in the experimental procedure of Example 1, 10 g of 1,3-propanediol, 1,3-butanediol, 1,4-butanediol and 1,6-hexanediol in a liquid state were added to 5 g of hydrocarbon oil , 10, 15 and 20 grams were injected.

Comparative Example 1

The procedure of Example 5 was repeated except that water was used instead of the diol compound in Example 5.

Comparative Example 2

The procedure of Example 5 was repeated except that methanol was used instead of the diol compound in Example 5.

The organic acid removal efficiency was confirmed, and the experimental results are shown in Table 2 and FIG.

As shown in Table 2 and FIG. 3, the acidity of the hydrocarbon oil after the treatment with the diol compound increased with the mass ratio of the diol, and 1,6-hexanediol had the highest organic acid removal efficiency.

In the case of the water of Comparative Example 1, it was confirmed that the acidity after treatment did not further decrease at around 5. Therefore, it was confirmed that the addition of water could not remove the organic acid in the oil phase. The formation of an emulsion on oil was also confirmed in Fig. Therefore, in the case of water, it is difficult to use it as an organic acid extracting agent in comparison with a diol material in terms of efficiency and emulsion generation.

In addition, the methanol of Comparative Example 2 showed similar efficiency to that of the diol except for a low mass ratio. However, methanol has another problem that can not be used for extraction of organic acids apart from extraction efficiency. FIGS. 4 and 6 show liquid-liquid equilibrium forms after extraction of diol and methanol, respectively. In the case of methanol, the phase is present at the upper part because it is lower in density than the oil phase, and in the case of the diol, the phase is present at the lower part because the density is higher than the oil phase. As shown in Fig. 6, it was confirmed that turbidity was retained in the case of the oil phase present at the bottom. This indicates that methanol is included as an impurity on the oil phase because methanol is added in an oil phase. Conversely, in the case of the diol, the boundary between the oil phase and the diol phase is clearly separated and the impurities are not present in the oil phase. In the case of methanol, the organic acid removal efficiency is similar to that of the diol, but it is confirmed that it is difficult to remove organic acid as compared with the diol material because of the same reason as the other mixture because it is contained as impurities in the oil phase at the phase separation.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the invention will be defined by the claims and their equivalents.

1: High acidity crude oil or hydrocarbon oil
2: Crude oil or hydrocarbon oil with lowered acidity after treatment
3: Diol compound containing organic acid after treatment
4: Diol compound whose content of organic acid is lowered through crystallization
5: The organic acid removed from the diol compound through crystallization
100: liquid-liquid extractor
200: Solid-liquid extractor

Claims (11)

A method for removing organic acids from a high acidity crude oil or hydrocarbon oil comprising the steps of:
(a) preparing a mixture by mixing crude oil or hydrocarbon oil containing organic acids with 1.5 to 5.0 times (weight ratio) of 1,6-hexanediol of said crude oil or hydrocarbon oil;
(b) separating crude oil or hydrocarbon oil and 1,6-hexanediol containing organic acid through liquid-liquid phase separation of said mixture; And
(c) removing the organic acid from 1,6-hexanediol containing organic acid.
delete The method of claim 1, wherein the high acidity crude oil or hydrocarbon oil has a total acid number (TAN) of 1 or more.
The method of claim 1, wherein the step (c) comprises crystallizing 1,6-hexanediol containing organic acid to remove the organic acid.
The method of claim 1, further comprising recycling the organic acid-free 1,6-hexanediol to the step (a).
The method of claim 1, wherein the 1,6-hexanediol is in a solid or liquid phase.
delete The method of claim 1, wherein the step (a) is carried out at a temperature ranging from the melting point of the 1,6-hexanediol to the boiling point.
The method of claim 8, wherein the step (a) is carried out at a stirring speed of from 100 to 2000 rpm for 10 minutes to 5 hours at a temperature of 60 to 90 ° C.
The method of claim 1, wherein the step (b) is carried out at 60 to 90 ° C for 10 minutes to 2 hours without stirring.
The method according to claim 1, wherein the step (c) is carried out at a temperature of less than 10 ° C. of the melting point of the 1,6-hexanediol.

Images