WO2007086661A1

WO2007086661A1 - Method of removing the calcium from hydrocarbonaceous oil

Info

Publication number: WO2007086661A1
Application number: PCT/KR2007/000179
Authority: WO
Inventors: Byong Sung Kwak; Ik Sang Yoo; Dong Hyon Sheen; Sang Chul Lim; Jin Kyu Choi; Tae Won Uhm
Original assignee: Sk Energy Co., Ltd.
Priority date: 2006-01-25
Filing date: 2007-01-10
Publication date: 2007-08-02

Abstract

Disclosed is a method of removing calcium from hydrocarbonaceous oil, and more particularly, a method of removing calcium from hydrocarbonaceous oil, including adding a lipophilic compound to hydrocarbonaceous oil including calcium-containing crude oil or hydrocarbon residue to thus prepare a homogeneous mixture, which is then hydrolyzed and reacted with the calcium compound present in the oil so that the calcium can be more easily and efficiently removed. Unlike conventional methods, since a compound soluble in hydrocarbonaceous oil, including high-calcium crude oil, is used, there is no need for a process of separating a lipophilic layer from an aqueous layer using an excessive amount of water, thus easily and efficiency removing calcium. Consequently, the method of the invention is advantageous in terms of industrial usefulness.

Description

[DESCRIPTION] [Invention Title]

METHOD OF REMOVING THE CALCIUM FROM HYDROCARBONACEOUS OIL [Technical Field]

The present invention relates to a method of removing calcium from hydrocarbonaceous oil, and more particularly, to a method of removing calcium from hydrocarbonaceous oil, in which a lipophilic compound, represented by Formula 1 below, is dissolved in hydrocarbonaceous oil, including calcium-containing crude oil or hydrocarbon residue, to thus prepare a homogeneous phase, from which calcium can then be efficiently removed:

Formula 1

wherein Rl and R2, which are the same as or different from each other, are hydrogen, methyl, ethyl, propyl, phenyl, bromo, chloro, trifluoromethyl, or 3-(4-chlorophenyl), or Rl and

R2 may be chemically bonded to each other to form a ring together, in which one or more members of the ring may be optionally substituted with a hetero atom, such as nitrogen, oxygen, or sulfur.

[Background Art] Calcium in crude oil is mainly present in the form of calcium naphthenate. Further, crude oil having a high calcium content is crude oil (Heidrum, Captain) native to the North Sea, crude oil (Bohai, Shangri) native to China, crude oil (Shering) native to Indonesia, and crude oil (San Joaquin Valley) native to North America, as well as crude oil (Doba, Quito) native to West Africa, including Chad and Sudan, where new oil wells are being drilled these days. hi the high-calcium crude oils, since calcium naphthenate functions as an emulsion stabilizer, problems related to the separation of an aqueous layer during a desalting process are caused, and thereby an excessive amount of water flows into a refining device, or an excessive amount of organic material is fed into a wastewater treatment plant, undesirably resulting in low efficiency of the overall process of crude oil treating. Further, calcium present in the residue of the crude oil passed through the refining device causes problems since it functions to inactivate the catalyst within a short time period in a catalytic cracking process using an FCCU (Fluid Catalytic Cracking Unit) or an RFCCU (Residue Fluidized Catalytic Cracking Unit). Moreover, when the residue is combusted in a boiler, a large amount of calcium sulfate is produced in the boiler, drastically reducing boiler efficiency. Therefore, high-calcium crude oil requires an additional calcium treatment process before a typical refining process is conducted. Furthermore, the demand for efficient calcium removal methods, capable of assuring economic benefits with respect to general crude oil, is increasing.

US Patent No. 4,778,589 discloses a method of removing calcium from hydrocarbonaceous oil using an aqueous solution of hydroxo carboxylic acid, in particular, citric acid. When calcium is removed, calcium citrate is produced. Calcium citrate has low solubility in water, and thus a large amount of precipitate remains in a desalting device, remarkably decreasing calcium removal efficiency. Further, upon the removal of calcium from hydrocarbonaceous oil containing high concentrations of calcium, the pH of the aqueous solution that is used becomes too high, leading to device corrosion problems.

In addition, US Patent No. 4,778,590 discloses a method of removing calcium using amino-carboxylic acid or salts thereof, in particular, EDTA (Ethylene Diamino Tetra Acetic Acid). However, since the EDTA, having low solubility in water, requires the use of an excessive amount of water to prepare it into a calcium removal agent in the form of an aqueous solution, it is disadvantageous in terms of transport and use, resulting in economic and industrial inefficiency.

In addition, US Patent No. 4,778,591 discloses a method of removing calcium from hydrocarbonaceous oil using aqueous carbonic acid and salts thereof, in particular, ammonium carbonate. However, the above method has been reported to be economically disadvantageous because ammonium carbonate should be used in an amount about 5 times as much as the amount of calcium in order to achieve calcium removal efficiency of 90% or higher. In addition, US Patent Nos. 4,778,592 and 4,789,463 disclose a method of removing iron from hydrocarbonaceous oil using EDTA and citric acid, respectively. Further, US Patent No. 4,853,109 discloses a method of removing calcium using dicarboxylic acid, in particular, oxalic acid. However, since the solubility of oxalic acid in water is typically low, it is difficult to prepare the acid in the form of a high-concentration aqueous solution. Thus, when the acid is formed into a calcium removal agent, it requires the use of an excessive amount of water, and therefore it is disadvantageous in terms of transport and use, incurring economic and industrial problems. Furthermore, the above patent discloses the use of 50% aqueous solution in a desalting extraction process, and is consequently difficult to use industrially.

US Patent No. 4,988,433 discloses the use of monocarboxylic acid and salts thereof for calcium removal. In particular, ammonium carboxylic acid is used. In order to achieve calcium removal efficiency of 80% or higher, acetic acid should be used in an amount about 30 times as much as the amount of calcium. Also, in a continuous process, acetic acid is used in an amount 3.3 times as much as the amount of calcium, but the removal efficiency is low, around 46%, and thus the above technique is not industrially important. Further, due to the thorough dissolution of acetic acid in hydrocarbonaceous oil, the upper portion of a distillation device may undesirably corrode in processes subsequent to a desalting process.

US Patent No. 5,593,573 discloses the use of sulfonic acid or its salts, in particular, ammonium sulfate, as a calcium removal agent. According to the above patent, for the optimal use of ammonium sulfate, the pH of the aqueous solution layer is controlled to be 6-8, and also, a 10% precipitation inhibitor is used therewith so as to prevent the production of a great amount of calcium sulfate in the desalting process. Thus, the above patent suffers because the use of the agent is complicated and economic benefits are negated. Further, to maintain the calcium removal efficiency at 70% or higher, ammonium sulfate should be used in an amount at least 6 times the amount of calcium, leading to negation of economic and industrial benefits. Furthermore, since sulfonic acid, which is a strong acid, remains in the hydrocarbonaceous oil, it causes problems of corrosion of the distillation device in processes subsequent to the desalting process.

US Patent Application Publication Nos. 2004-45875 and 2005-241997 disclose a method of removing metal and amine from hydrocarbonaceous oil using aqueous hydroxy acid. Examples of the hydroxy acid used include glycolic acid, glucolic acid, C2-C4 alpha-hydroxy acid, and polyhydroxy acid. Among these, the glycolic acid is problematic because it remains in the hydrocarbonaceous oil and consequently corrodes the upper portion of a distillation column at high temperatures in processes subsequent to the desalting process.

US Patent No. 6,905,593 discloses a method of removing calcium from hydrocarbonaceous oil by maintaining the pH of an aqueous layer in the range of 3.0~5.0 using acetic acid and aqueous ammonia. However, the control of the pH requires an excessive amount of water, and acetic acid should be used in an amount 9 times the amount of calcium so as to assure calcium removal efficiency of 98% or higher, and thus the industrial usefulness of the above method is limited. Further, in the case where a great amount of acetic acid is used, secondary corrosion of the distillation device is caused by the acetic acid dissolved in hydrocarbonaceous oil.

Japanese Unexamined Patent Publication No. Sho. 52-30284 discloses a method of removing various metals from crude oil using inorganic acid, alkyl phosphate ester and an oxidant. Japanese Unexamined Patent Publication No. Sho. 47-22947 discloses a method of removing metal using alkyl phosphate ester and alkyl carboxylic acid in the absence of inorganic acid, but it results in low metal removal efficiency.

In the above patents, with the goal of removing calcium from hydrocarbonaceous oil including crude oil, inorganic acid or organic acid, in particular, monoacid, diacid, or hydroxy acid is used in such a manner that it is dissolved in water to thus prepare a high concentrate for a calcium removal agent, which is then diluted with a great amount of water in the desalting process. However, the process of adding diacid in the desalting process to remove calcium is disadvantageous because a great amount of water should be used to mitigate the problem of low solubility of the diacid in the aqueous layer, and the newly produced calcium salt precipitates due to the low solubility thereof. In the case of monoacid, since excess calcium removal agent should be used, there are problems related to the control of the pH of the aqueous layer and corrosion. Further, the use of hydroxy acid undesirably results in economic and industrial disadvantages concerning secondary corrosion and problems analogous thereto.

Moreover, the above methods are useful for rapidly mixing the lipophilic layer, comprising hydrocarbon oil, with the aqueous layer, in which the calcium removal agent is dissolved, so as to increase the calcium removal efficiency, and furthermore, for generating an interfacial reaction between the two layers, which are not mixed with each other. Hence, in the case of using the crude oil, having high concentrations of calcium, it is difficult to mix, attributable to the viscosity thereof, and thereby limitations are imposed on the use of the high- concentration mixing ratio. Ultimately, all the methods for increasing the calcium removal efficiency have the above-mentioned problems. [Disclosure] [Technical Problem]

As a result of conducting research to avoid the problems encountered in the related art, the present inventors have found that, when a lipophilic compound represented by Formula 1 is used, it can be directly added to hydrocarbonaceous oil to thus dissolve it and can consequently be provided in a homogeneous phase in which the compound is uniformly dissolved in crude oil or hydrocarbonaceous oil without the use of an excessive amount of water or another solvent, and furthermore, using only the water present in hydrocarbonaceous oil or a small additional amount of water, the compound is hydrolyzed to thus react with a calcium compound, thereby easily and efficiently removing calcium from hydrocarbonaceous oil, including high-calcium crude oil or hydrocarbon residue.

Accordingly, an object of the present invention is to provide a novel method of efficiently removing calcium from hydrocarbonaceous oil, including crude oil or hydrocarbon residue. [Technical Solution]

In order to accomplish the above object, the present invention provides a method of removing calcium from crude oil, comprising steps of:

1) adding a compound represented by Formula 1 below to a hydrocarbon source containing calcium, thus preparing a homogeneous mixture: Formula 1

wherein Rl and R2, which are the same as or different from each other, are hydrogen, methyl, ethyl, propyl, phenyl, bromo, chloro, trifluoromethyl, or 3-(4-chlorophenyl), or Rl and R2 may be chemically bonded to each other to form a ring together, in which one or more members of the ring may be optionally substituted with a hetero atom, such as nitrogen, oxygen, or sulfur;

2) hydrolyzing the compound represented by Formula 1 in the homogeneous mixture, thus producing a compound represented by Formula 2 below:

Formula 2

R1 R2

OHHO

wherein Rl and R2 are as defined above; 3) subjecting the compound represented by Formula 2 along with calcium naphthenate present in the homogeneous mixture to metal substitution, thus producing calcium dicarboxylate; and

4) desalting the calcium dicarboxylate to thus remove it. [Advantageous Effects] Unlike conventional calcium removal methods, in the method of removing calcium according to the present invention, a lipophilic dicarboxylic anhydride compound is completely dissolved in calcium-containing oil, such as crude oil, to form a homogeneous phase, which is then subjected to hydrolysis to thus produce an aqueous compound having a carboxylic group, after which the aqueous compound is reacted with calcium so that the calcium is deposited as an insoluble material for easy removal, thereby effectively removing calcium while solving problems related to the limited mixing ratio of crude oil having high concentrations of calcium, pH control, and transport and use thereof due to the use of excessive amount of water. Thus, the method of the present invention can be advantageously applied to the extraction of high-calcium crude oil from an oil well, the pretreatment of crude oil before distillation, the removal of calcium from hydrocarbon mixtures, and the efficient removal of calcium from other oils containing calcium, and is therefore expected to be industrially useful. [Best Mode]

Hereinafter, a detailed description will be given of the present invention.

According to the present invention, the method of efficiently removing calcium from hydrocarbonaceous oil including calcium-containing crude oil or hydrocarbon residue is provided. The method of the present invention is characterized in that it selectively uses a lipophilic compound represented by Formula 1 below:

Formula 1

wherein Rl and R2, which are the same as or different from each other, are hydrogen, methyl, ethyl, propyl, phenyl, bromo, chloro, trifluoromethyl, or 3-(4-chlorophenyl), or Rl and R2 may be chemically bonded to each other to form a ring together, in which one or more members of the ring may be optionally substituted with a hetero atom, such as nitrogen, oxygen, or sulfur.

More specifically, a lipophilic dicarboxylic anhydride compound, which may be converted into an aqueous compound having a carboxylic group through hydrolysis, is selected, and then a homogeneous mixture is prepared. Thereafter, a compound having a carboxylic group, produced through hydrolysis, is reacted with calcium in the oil, yielding an insoluble compound, capable of being deposited, whereby the calcium can be effectively removed through the simple and easy process of the invention.

The method of removing the calcium according to the present invention comprises 1) adding a lipophilic compound represented by Formula 1 to a hydrocarbon source containing calcium, thus preparing a homogeneous mixture; 2) hydrolyzing the compound represented by Formula 1 in the homogeneous mixture, thus producing a compound represented by Formula 2 below:

Formula 2

wherein Rl and R2 are as defined above; 3) subjecting the compound represented by Formula 2 and calcium naphthenate present in the homogeneous mixture to metal substitution, thus producing calcium dicarboxylate; and 4) desalting the calcium dicarboxylate to thereby remove it. Below, individual steps are described in detail.

The present invention is intended to remove calcium from a hydrocarbon source, not limited to high-calcium crude oil and hydrocarbon residue, including atmospheric residue or vacuum residue, which is a semi-finished product obtained in a crude oil refining process, but also including other hydrocarbon oils, such as shale oil, shale sands, liquefied coal oil, and tar sands. Accordingly, the method of the present invention enables the effective removal of calcium from a hydrocarbon source containing 10 to 3,000 ppm calcium. First, an appropriate lipophilic dicarboxylic anhydride compound represented by

Formula 1, which may be converted into an aqueous compound having a carboxylic group through hydrolysis, is selected and added to a hydrocarbon source including calcium-containing crude oil or hydrocarbon reside from which the calcium should be removed.

Upon the addition thereof, the compound may be directly added in a solid phase or in a liquid phase, or alternatively, may be added in the form of a high-concentration solution through dissolution in a diluting agent. As the diluting agent, any solvent may be used, as long as it may dissolve the dicarboxylic anhydride compound represented by Formula 1, with the exception of water. Examples of a general organic solvent include, but are not limited to, acetone, benzene, xylene, kerosene, 1,4-dioxane, chloroform, carbon tetrachloride, ethylacetate, dimethylforrnamide, tetrahydrofuran, dimethylsulfoxide, sulfolane, methylethylketone, and/or diethyleneglycol dimethylether, and preferably, xylene, dimethylformamide, tetrahydrofuran, dimethylsulfoxide, diethyleneglycol dimethylether and/or 1,4-dioxane. As such, although the concentration of the compound to be diluted varies with the solvent, it preferably falls within the range from 5 to 80 wt%, and more preferably from 20 to 60 wt%.

The compound represented by Formula 1 is used in a molar ratio ranging from 0.5 to 20, and preferably 1.0 to 10 relative to the amount of calcium contained in the crude oil. When the molar ratio is less than 0.5, the removal efficiency is decreased in terms of the equivalent reaction. On the other hand, when the ratio exceeds 20, the disposal cost is increased, and furthermore, the cost of post-treatment in a wastewater disposal plant after the desalting process is greatly increased.

In the case where the compound represented by Formula 1 is added to the crude oil or hydrocarbon oil to thus prepare a homogeneous mixture, any method which is known to those skilled in the art may be applied. For example, the added compound is stirred at a predetermined temperature of 20~80°C, and preferably 30~50°C, for a time period ranging from 1 sec to 2 hours, and preferably from 0.2 min to 0.5 hours, so as to realize complete dispersion and sufficient dissolution thereof. Thereby, a homogeneous mixture, in which the anhydride compound represented by Formula 1 is completely dissolved, may be obtained. Thereafter, the compound represented by Formula 1 is hydrolyzed using water which is already present in the crude oil, thereby producing the compound represented by Formula 2. hi the crude oil, since water is typically present in an amount of 0.1 to 0.5%, the compound may be hydrolyzed even without the use of additional water. However, in the case of vacuum residue having no water, water is further added in an amount not less than the minimum amount required to hydrolyze the compound represented by Formula 1. As such, water is used in a molar ratio ranging from 1 to 10, and preferably 1.5 to 5, relative to the amount of the compound represented by Formula 1. The hydrolysis is performed at a reaction temperature of 30~90°C, and preferably 40~80°C, for a reaction time of 1-30 min, and preferably 5-10 min. The compound thus produced, represented by Formula 2, is present in a dissolved and homogeneous state. hi the homogeneous mixture, the compound represented by Formula 2 and the calcium naphthenate are subjected to metal substitution, thus producing calcium dicarboxylate. As such, in order to efficiently realize metal substitution between calcium metal which is present in a very small amount and viscous crude oil or hydrocarbon residue, it is very important that the stirring speed of the reactor be controlled. For example, a stirring speed of 100-4,000 φm, and preferably 200-3,000 rpm, should be maintained to assure a desired mixing state. In particular, in the case of a continuous process, the stirring speed of an impeller is increased when a mixing pump and a centrifugal pump have the same mixing capability. For efficient metal substitution, it is preferred that a reaction temperature of 30-180°C, and preferably 50~140°C, and a reaction time ranging from 1 sec to 4 hours, and preferably from 1 min to 60 min, be maintained.

Finally, the produced calcium dicarboxylate is removed through a desalting process. To this end, a general production process may be applied, hi the present invention, the process was performed using a PED (Portable Electronic Desalter, available from Inter Av.). For example, at a DC voltage of 3,000 Volts, the desalting process was performed for a time period ranging from 10 min to 2 hours, and preferably 1 hour, and at 50~100°C, and preferably 9O⁰C. In this case, water may be used in an amount of 5~50%, and preferably 10%. Further, an additive is used to increase oil-water separation efficiency, and any additive typically known in the art may be used. For example, a commercially available demulsifier (Prochem 2X24, Petrolite) may be used in an amount of 1-100 ppm, and preferably 2—10 ppm.

In the present invention, the method of removing the calcium is preferably conducted at a reaction pressure ranging from atmospheric pressure to 20 atm.

In this way, according to the method of the present invention, since a lipophilic compound that is soluble in hydrocarbonaceous oil, such as crude oil or hydrocarbon residue, is used, it is possible to directly dissolve the calcium removal agent in the oil layer, thereby solving conventional problems related to the use of a calcium removal agent which is not oily but aqueous, that is, the use of excessive amounts of water, pH control, corrosion, and the limited mixing ratio of crude oil containing high concentrations of calcium. Furthermore, calcium can be easily and economically removed at high efficiency.

Therefore, the method of the present invention is expected to be variously applicable to diverse fields requiring the removal of calcium, in particular, the extraction of high-calcium crude oil from oil wells, the pretreatment of crude oil before distillation, and the removal of calcium from hydrocarbon mixtures and other oils. [Mode for Invention]

Below, the present invention is more specifically described through the following examples, but the scope of the present invention is not limited thereto.

Example 1 : Model Reaction using Xylene

In order to evaluate the effectiveness of the present invention for removing calcium from crude oil using a lipophilic dicarboxylic anhydride compound, a simulation test was performed using naphthenic acid having 3% calcium naphthenate dissolved therein (available from Wako).

For the model reaction, into a 500 ml round bottom flask, 10 g of naphthenic acid containing 3% calcium was added, and 330 ml of xylene was then added, after which they were strongly stirred using a mechanical stirrer to thus produce a homogeneous solution. As the lipophilic compound, maleic anhydride was used. 877 mg of maleic anhydride was added, and the temperature was increased to 5O⁰C, followed by performing a stirring process for 10 min. Water was added in a molar ratio of 1.8 relative to the added amount of the maleic anhydride (hereinafter, referred to as "MAN"). Subsequently, to confirm the metal substitution of calcium depending on temperature, the temperature of the reaction solution was variously increased, and the reaction time was varied.

During the reaction, insoluble material having a very small size was seen to be deposited in the reaction solution. The reaction solution was transferred into a separator funnel, after which the organic solution was washed with 50 ml of water. From the organic solution thus obtained, a small portion was taken and thus the calcium removal efficiency was measured through an ICP test. The results of Ca removal efficiency depending on changes in temperature and reaction time are shown in Table 1 below.

TABLE l

As is apparent from Table 1, the calcium was efficiently and thoroughly removed using the lipophilic compound according to the present invention.

Examples 2 to 11 and Comparative Examples 1 and 2 Test for 20% Doba Blend

85% Doba crude oil, native to West Africa (Chad), was blended with general crude oil, to thus prepare crude oil for a test having a concentration of 20%, which is referred to as 20% Doba blend. As a result of analysis through ICP, the concentration of calcium was measured to be an average of 56 ppm. Into a 500 ml high-pressure reactor, 250 g of 20% Doba blend was added. 68.6 mg of

MAN was added in solid phase or in liquid phase, in which it was dissolved in an organic solvent, after which the stirring speed was set at 1,000 rpm and the reaction temperature was increased to 4O⁰C, followed by performing the stirring process for 10 min. 25.2 μl of water was added thereto, and the reaction temperature was increased to 90°C, followed by performing the stirring process for 2 hours.

The reaction solution was removed from the high-pressure reactor, and 90 g thereof was placed in a 100 ml reactor. 10 ml of water was added thereto and 1 mg of a demulsifier

(Prochem 2x24, Petrolite) was then added, followed by performing a stirring process at 9O⁰C for 1 hour. After the stirring process, the reaction solution was transferred into the glass tube of a PED (Portable Electric Desalter) in order to conduct a desalting process.

As the PED, EDPT (Electrostatic Dehydration & Precipitation Tester)-228, made by

Inter Av Inc (San Antonio, Texas, USA), was used. The glass tube containing the sample was placed in the PED, and then the PED was operated at 90⁰C for 1 hour at 3000 Volts to realize good oil-water separation. After the completion of the oil- water separation, 20 g of the sample was removed from the middle layer of the separated oil and then subjected to an ICP test. The results of the removal efficiency depending on the type of MAN that was added (solid, and solutions of xylene, 1,4-dioxane, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, and diethyleneglycol dimethylether) and on the molar ratio thereof are shown in Table 2 below. In Table 2, regardless of whether the MAN was added in solid phase or in liquid phase, in which it was diluted with a solvent, the calcium removal efficiency was superior.

TABLE 2

Examples 11 to 13 Comparison of Calcium Removal Efficiency depending on Mixing Ratio of Doba Crude Oil

To compare the reactivity at high concentrations with a 20% Doba mixing ratio, samples having 50% and 85% Doba mixing ratios were prepared. All reaction conditions and processes were the same as in Example 2.

TABLE 3

As is apparent from Table 3, even when the crude oil containing high calcium was mixed at high ratios, the calcium removal efficiency was high.

Examples 14 to 18

Comparison of Removal Efficiency depending on Substituent The reaction was conducted in the same manner as in Example 2, with the exception that the substituents Rl and R2 of the compound represented by Formula 1 were changed, other than the MAN.

TABLE 4

Examples 19 and 20

Change of Removal Efficiency with Pressure

The calcium removal reaction was conducted in the same manner as in Example 2, with the exception that the reaction was performed under atmospheric pressure and high pressure.

TABLE 5

Examples 21 to 25

Change of Removal Efficiency with Temperature and Time

In a production site equipped with a distillation device, the period of time required to increase the temperature of crude oil from room temperature to 140°C was 10 min. Thus, in order to evaluate the commercial application efficiency of the method of the present invention, the reaction was conducted in the same manner as in Example 2, with the exception that the reaction time and temperature were adjusted to be suitable for the production site, and a 20% Doba blend was used, and thus the reaction conditions were simulated.

TABLE 6

According to the examples, in the distillation process, the period of time required to transfer the crude oil to the desalter was 10 min. As such, during the first 3 min, the temperature was increased from room temperature to 140°C, and, for the next 7 min, the reaction temperature was maintained at 140°C before the oil was added into the desalter. As is apparent from Table 6, which shows the results of testing to determine the time and temperature required for treating the crude oil used in an actual distillation plant, when the method of the present invention was applied at a production site, excellent efficiency could be realized.

Claims

[CLAIMS]

[Claim 1]

A method of removing calcium from hydrocarbonaceous oil, comprising steps of: 1) adding a compound represented by Formula 1 below to a hydrocarbon source containing calcium, thus preparing a homogeneous mixture: Formula 1

wherein Rl and R2, which are the same as or different from each other, are hydrogen, methyl, ethyl, propyl, phenyl, bromo, chloro, trifluoromethyl, or 3-(4-chlorophenyl), or Rl and R2 may be chemically bonded to each other to form a ring together, in which one or more members of the ring may be optionally substituted with a hetero atom, including nitrogen, oxygen, or sulfur;

2) hydrolyzing the compound represented by Formula 1 in the homogeneous mixture, thus producing a compound represented by Formula 2 below: Formula 2

wherein Rl and R2 are as defined above;

3) subjecting the compound represented by Formula 2 and calcium naphthenate present in the homogeneous phase to metal substitution, thus producing calcium dicarboxylate; and

4) desalting the calcium dicarboxylate, to thus remove it. [Claim 2]

The method according to claim 1, wherein the compound represented by Formula 1 in the step 1) is used in a molar ratio of 0.

5 to 20 relative to an amount of calcium contained in the hydrocarbon source. [Claim 3]

The method according to claim 1, wherein the step 2) is performed through stirring at a reaction temperature ranging from 20 to 80°C for a reaction time ranging from 1 sec to 2 hours. [Claim 4]

The method according to claim 1, wherein the compound represented by Formula 1 in the step 1) is added in solid phase or in liquid phase. [Claim 5]

The method according to claim 1, wherein the compound represented by Formula 1 in the step 1) is added in a state of being diluted to a concentration of 5 to 80 wt% with an organic solvent.

[Claim 6]

The method according to claim 5, wherein the organic solvent is one or more selected from a group consisting of acetone, benzene, xylene, kerosene, 1,4-dioxane, chloroform, carbon tetrachloride, ethylacetate, dimethylformamide, tetrahydrofuran, dimethylsulfoxide, sulfolane, methylethylketone, and diethyleneglycol dimethylether.

[Claim 7]

The method according to claim 1, wherein the step 2) further comprises adding water in a molar ratio of 1 to 10 relative to the amount of the compound represented by Formula 1.

[Claim 8] The method according to claim 1, wherein the step 3) is performed at a stirring speed of 100^,000 rpm, a reaction temperature of from 30 to 180°C, and a reaction time of from 1 sec to 4 hours.

[Claim 9] The method according to claim 1, wherein the hydrocarbon source contains 10-3,000 ppm calcium. [Claim 10]

The method according to claim 1, which is performed at a reaction pressure ranging from atmospheric pressure to 20 arm. [Claim 11]

The method according to claim 1, wherein the step 4) further comprises adding an additive to increase separation efficiency. [Claim 12]

The method according to claim 1, wherein the hydrocarbon source is crude oil, atmospheric residue, vacuum residue, shale oil, shale sands, liquefied coal oil, or tar sands. [Claim 13]

A method of removing calcium from hydrocarbonaceous oil, comprising: 1) selecting a lipophilic dicarboxylic anhydride which is converted into an aqueous compound having a carboxylic group through hydrolysis; 2) adding the selected lipophilic dicarboxylic anhydride to a hydrocarbon source, thus forming a homogeneous mixture;

3) hydrolyzing the lipophilic dicarboxylic anhydride in the homogeneous mixture, thus forming a compound having a carboxylic group;

4) subjecting the compound having a carboxylic group and calcium naphthenate in the homogeneous mixture to metal substitution, thus producing calcium dicarboxylate; and ) desalting the calcium dicarboxylate to thus remove it.