MXPA05007911A - Process for reducing naphthenic acidity in oil or fractions thereof. - Google Patents

Abstract

Described is a process for reducing naphthenic acidity in petroleum oil or its fraction comprises: providing the oil supply (103)/ (203)/ (303) (0.1-99 wt.%) in water that is emulsified/dispersed in the oil, where the oil contain salts and naphthenic acid content is 0.1-10 mg that are measured by total acid number (TAN) measurement using KOH/g; sending the oil with the water towards a device, which is emitting microwave radiation, where the oil is subjected under the microwave radiations in liquid phase at 50-350[deg]C under 0.7-4.5 MPa in which the microwave radiations have influencing distance of 1 mm-30 cm of the oil, in the presence of salts, applied temperature and the high permittivity of the water droplets involve absorption of heat preferably heating water in the place of oil, the naphthenic compounds interface between the droplets, and the oil absorb the heat; decomposing carboxylic acids (that is responsible for naphthenic acidity) of 320[deg]C to liberate CO2; separating the formed gas, water and oil phases using separating device (106)/ (106')/ (112)/ (117)/(208)/ (208')/ (214)/(219)/ (310)/ (310')/ (316)/ (321); and recovering the oil (108)/ (113)/ (119)/ (210)/ (215)/ (221)/ (312)/ (317)/ (323) having reduced amount of naphthenic acids. The inventive process is applied for reducing naphthenic acid in oil or its fractions during the oil production-phase performed in refineries or any other industrial facility.

Description

PROCEDURE TO REDUCE THE NATIVE NATURAL ACIDITY OF OILS OR THEIR FRACTIONS FIELD OF THE INVENTION The present invention relates to a process for reducing the naphthenic acidity of oils or their fractions, more specifically to a process in which the naphthenic acidity is reduced by the contact of the oil with emulsified or dispersed water and in the presence of salts, with an electromagnetic field in the microwave spectrum, in liquid phase, for which the proportion of naphthenic acids in the oil charge or its fractions is reduced.

BACKGROUND OF THE INVENTION The new discoveries of increasingly heavy oils, with high naphthenic acidity and high viscosity, are an important challenge for the oil industry. Petroleum with high levels of organic acids are highly corrosive to the equipment used for processing. Currently, some Brazilian oil blends have proven to be considerably more corrosive than traditionally refined ones, forcing units, especially distillation, to undergo reforms to install more noble materials. As there is no reliable measure of the corrosivity of each oil, one can not know in a certain way which material of a precise unit is built for an acceptable corrosion index. The material chosen should be as suitable as possible, since excessive corrosion leads to risks associated with spills, premature equipment replacement and production stoppages. On the other hand, - chemically resistant materials such as stainless steel are expensive and are reflected in the fixed cost of the unit and the return on capital invested. The reduction of naphthenic acidity, in addition to avoiding the problems associated with corrosion, improves the desalting / electrostatic treatment efficiency of one of the most important equipment in production or refining units. The poor operation of this equipment or poor performance of this treatment causes serious damage to the processing units, limiting the useful life and increasing the cost of processing, having as main consequences: a) corrosion in equipment, the most affected being the units of fractionation, the condensers of head fractions, internal parts of the head area, tubulators, control valves, head and the tower's own lateral parad; b) deposition of salts in heat exchangers and furnaces, since for many of them the solubility decreases with the increase in temperature and / or vaporization of water occurs with precipitation of salts; as a consequence, there is an increase in the loss of charge in the preheating battery, reduction in heat exchange performance, which causes an increase in fuel consumption in the ovens, also contributing to the coke arrangement inside the tubes. oven and limiting the load of the unit; c) presence of excess water in the process stream, which causes an increase in fuel consumption to heat and vaporize it, in addition to the instability of the process due to the presence of water pockets; d) increased consumption of chemical products to control pH and corrosion inhibitors, in addition to hindering the control of the addition of these products due to the instability of the concentration of chlorides, generating additions sometimes excessive and qas insufficient; e) presence of salts, sediments and solids, which causes the poisoning of the catalyst and worsens the quality of the fuel oil or asphalt. Among the different solutions already adopted to reduce the naphthenic acidity of oils and their derivatives, the use of mixtures of oils with different levels of acidity, the application of corrosion inhibitors, thermal treatments and hydrotreatments can be cited.

In the case of heat treatment, US Pat. No. 6 may be given as examples., 086,751 that points to reductions of 90% in IAT (total acidity index) for some Venezuelan crudes. The oil is initially subjected to a flash for the removal of water and subsequently the effluent is subjected to temperatures between 340 and 420 ° C with pressures below 7.5 MPa and reaction times of up to 2 hours. Under conditions of conventional reduction of viscosity, the reduction is situated at 80%. This alternative implies expenses in equipment, such as ovens and maturation vessels. Another form of reduction of naphthenic acidity is the hydrotreatment of oil in soft conditions. However, the life of the unit can be limited by the contamination of the catalyst and the consumption of hydrogen becomes high at the end of the campaign, increasing the cost of refining. Another alternative consists in the esterification of naphthonic acids by the addition of alcohols, with or without the presence of catalysts. However, this solution consumes large amounts of alcohol, increasing the cost of this process. The application of corrosion inhibitors is another solution adopted to contain the problem of acidity. Also, U.S. Patent No. 5,182,013 teaches that organic polysulfides are effective inhibitors of naphthenic acid corrosion in distillation units in refineries. U.S. Patent No. 4,647,366 teaches the addition of petroleum-soluble products of an alkynediol and an alkyl polyamine as inhibitors of naphthonic corrosion. The reduction of acidity can also be obtained through the treatment of petroleum with basic solutions of NaOH or KOH according to that taught in the North American patent No. 4,199,440. While this attempt at solution requires the use of fairly concentrated basic solutions and a critical point is the formation of emulsions with separation difficulties. Therefore this solution would be applicable only for low base concentrations. The treatment with a basic detergent based on sulfonate or calcium naphthenate containing at least 3% calcium is taught in US Pat. No. 6,054,042 in order to contain the problem of emulsions. The oil is treated at temperatures between 100 ° C to 170 ° C with stoichiometric proportions of calcium for acid functionality in the crude from about 0.025: 1 to 10: 1 moles, or 0.25: 10: 1, or other proportions may be used. U.S. Patent No. 6,258,258 teaches the use of ammonium anhydride solutions. The proposed treatment can be carried out in two stages, with a first stage under conditions of temperature and time sufficient to form ammonium salts of the naphthenic acids and with a second stage in which those ammonium salts are treated under temperature conditions and suitable time to form the naphthenic acid amides. US Patent No. 6,281,328 teaches the use of solutions of polymeric amines, such as polyvinyl pyridine to solve the problem of naphthenic acidity. U.S. Patent No. 4,300,995 teaches the treatment of coal and liquids obtained from coal, in addition to oily vacuum gas and petroleum residues having acidic functionalities, with basic solutions of quaternary hydroxides in alcohol or water, such as tetramethylammonium hydroxide in a liquid like alcohol or water. WO 01/79386 teaches, for the reduction of naphthenic acids, a basic solution with group IA, IIA and ammonium hydroxides and the application of a phase transfer agent, such as non-basic quaternary salts and polyethers. In North American Patent No. 6,190,541 the bases of hydroxides and / or phosphates with an alcohol are used for the desired reduction in the concentration of naphthenic acids. In U.S. Patent No. 5,985,137, the naphthenic acidity and the sulfur concentration of the petroleum are reduced through the reaction with alkaline earth metal oxides, forming neutralized compounds and alkaline earth metal sulphides. The temperature must be greater than 150 ° C for the removal of carboxylic acids and greater than 200 ° C for the formation of the sulfide salts. The applied pressure must keep the material without vaporizing. In general, most of the methodologies for the reduction of naphthonic acidity, which include thermal treatments without or with the addition of basic solutions, demand the application of surfactants to contain the problem of emulsions. Yet another attempt at solution is the use of adsorbents to absorb naphthenic acids. Thus, the Brazilian application PI 0202552-3, teaches the reduction of naphthenic acidity of oils or their fractions that have to be subjected to desalination and dehydration through a process comprising the steps of: a) contacting the oils containing Naphthenic acid or its fractions with an adsorbent, the adsorbent / petroleum ratio or its fractions being comprised in the zone of 0.1 to 5, at temperatures between 200 ° C and 500 ° C, under pressures between 0.01 to 0.3 MPag, and residence time between 1 second and 2 hours, in order to effect the desired reduction in naphthenic acidity and obtain a treated load; b) in the treated cargo, separating the used adsorbent from the petroleum or its fractions so as to produce a treated and separate charge, with reduced naphthenic acidity; and c) direct the treated and separated cargo to an additional treatment. The adsorbent used in this Brazilian application is a material with a high specific surface, comprised between 100 and 200 m2 / g, the material surface being covered by a film of high molecular weight carbon compounds. The compounds useful as adsorbents are carbon black, spent FCC catalyst and FCC coke catalyst. U.S. Patent Nos. 4,582,629 and 4,853,119 propose the use of microwaves to break emulsions, although they do not teach about the removal or reduction of naphthenic acidity. US Pat. No. 6,454,936 Bl teaches the reduction of the proportion of naphthenic acids contained in oils by forming a petroleum / water (P / A) emulsion and using solids. The oil is initially treated with between 0.1 to 5% by weight in relation to the weight of oil, a solid capable of adsorbing the acids present in the oil. The solids useful for the treatment are silica, alumina, coke, montmorillonite, bentonite, kaolinite and the like. The solids must be amphiphilic in nature, that is they must have a hydrophilic / lipophilic character. The solids are added with 5 to 30: by weight of water in relation to the oil at temperatures between 20 ° C and 220 ° C, the most preferred area being 25 ° C to 80 ° C, for 3 to 30 minutes, under pressures between 413.7 kPa up to 6895 kPa. The water is added to form an emulsion and separated into a plurality of layers. The separation can be carried out by any process known as centrifugation, decantation by gravity, hydrocyclones, such as microwaves, electrostatic separation and combinations of these methods. Although US Pat. No. 6,454,936 Bl mentions the use of microwaves to separate the emulsion, the purpose of the technology set forth herein is not the use of microwaves to reduce the concentration of naphthenic acids in petroleum, but only to separate the emulsion. The solid mixed with the oil before forming the emulsion is intended to absorb the naphthenic acids, as indicated in column 3, line 2 of the cited patent. As the naphthenic acids have an amphiphilic character, the amphiphilic solid will be able to preferentially adsorb the naphthenic acids. Despite the good relative results, the reduction of the concentration of naphthenic acids reported in the literature using solid adsorbents, an unfavorable aspect of this technology is the introduction of an additional stage of separation of adsorbent solids. In addition to this, the very fact of adding to the load to be treated a foreign material (the solid adsorbent) represents costs and disturbances in the system. Another disadvantage is that the adsorbents are generally used under severe conditions of temperature and pressure, which makes the process more expensive. Another innovative relevant aspect of the present invention, not described or suggested by the state of the art, is that the known methods must subject the entire load to the proposed treatment, for example to the heating process, during a certain residence time, which in general is no less than an hour. Currently, in the invention the necessary energy is used to heat only a fraction of charge (water droplets emulsified or dispersed in the hydrocarbon phase) during a residence time lower than that necessary in other processes. Without being bound to any specific theory, it is assumed as a hypothesis that a further advantage of the present invention is based on the fact that the naphthenic compounds in which the chain has a reduced number of carbon atoms are relatively more polar and with higher acid strength than longer or more complex analogue chain compounds have higher affinity and will be concentrated at the interface of the aqueous phase, which will allow greater effectiveness in the intended reduction. Likewise, it is verified that despite the advance of the technique, there is still a need for a process to reduce naphthenic acids from oil charges or their fractions, which includes the treatment of these charges, in the desalination or dehydration stage, with energy electromagnetic spectrum in the spectrum of microwaves in liquid phase, at temperatures between 50 ° C and 350 ° C, with separation of any gaseous phase formed, said procedure being described and claimed in the present application.

SUMMARY OF THE INVENTION In a general manner, the present invention relates to a method for reducing the concentration of naphthenic acids of a cargo of petroleum or its fractions, which comprises: a) providing a cargo of petroleum or its fractions with between 0.1 and 99% by weight of emulsified / dispersed water in the oil, said loading containing salts and a concentration of naphthenic acids measured as total acidity index between 0.1 and 10 mg KOH / g of oil; b) conduct the oil charge or its fractions with emulsified / dispersed water to a radiation emitting device in the microwave spectrum and subject said charge, in liquid phase, at a pressure comprised between 0.7 and 4.5 MPa, at temperatures between 50 ° C and 350 ° C, applying the microwave energy in the area of 1 mm to 30 cm to said oil load, so that the presence of salts, the applied temperature and the high dielectric constant of the water droplets, cause the heat is absorbed by the water in a localized way and that it warms preferably to the oil, whereas the naphthenic compounds that are in the interface between the droplets and the oil, receive this heat; c) effect the decomposition of the concentration of carboxylic acids that cause the naphthenic acidity in the oil charge or its fractions at temperatures around 320 °, generating CO2; d) separating any generated gas, water and oil phase by means of any driven device; e) recover oil with a reduced concentration of naphthenic acids, where: i) the cargo of oil or its fractions is free of any added solid; ii) the migration tendency of naphthenic acids towards the emulsified phase, concentrating these acids in a fraction of the total charge, allows the microwave radiation to be applied to a fraction lower than the total load. In the case of using a separation device that includes a microwave radiation emitter, the load will remain under the effect of this radiation during a residence time comprised between 20 seconds and 40 minutes. In case the radiation emitter is online, the residence time depends on the conditions of this project, such as flow rate and tubing diameter. Also, the invention provides a method of reducing naphthenic acids of hydrocarbon charges with emulsified or dispersed water, in the presence of salts, by the application to this charge, of energy in the microwave zone. The invention also proposes a process for reducing naphthenic acids from hydrocarbon fillers with emulsified or dispersed water, in the presence of salts, in which the naphthenic compounds found at the interface of the droplets and oil receive the heat absorbed by the water in localized form, preferably heating to oil. The present invention further provides a method of reducing naphthenic acids from hydrocarbon charges with emulsified or dispersed water, in the presence of salts, in which solid adsorbents and other chemical products are dispensed in addition to the process. The invention also provides a method of reducing naphthenic acids from hydrocarbon fillers with emulsified or dispersed water, in the presence of salts, with minimization of dilution water consumption and reduction of losses by dragging oil in the brine, significantly reducing generation of hydraulic effluents and improving their qualities, as well as a reduction in refining costs due to the reduction of expenses with the treatment of effluents and with expenses for internal coating of critical equipment subject to naphthenic corrosion, with more expensive materials, and resistant to the corrosion. The invention also provides a method of reducing naphthenic acids from hydrocarbon charges with emulsified or dispersed water, in the presence of salts, in which the migration tendency of naphthenic acids towards the emulsified phase concentrates those acids in a charge fraction total, facilitates the application of the proposed technique in the fraction lower than the total load.

BRIEF DESCRIPTION OF THE DRAWINGS The attached figure 1 is a schematic flow diagram of a first embodiment of the method of the invention, in which the microwave radiation is applied in the stage of phase separation. Figure 1A depicts a process configuration with three phase separation in a gas phase, an oil phase and an aqueous phase. Figure IB presents a configuration of the process with separation in a gas phase and a water / oil liquid phase. Figure 1C depicts a process configuration with separation of a gas and oil stream from an aqueous phase. The attached figure 2 is a schematic flow diagram of a second embodiment of the method of the invention, in which the microwave radiation is applied in line, after a mixing device and before a phase separation device. Figure 2A depicts a process configuration with three phase separation in a gas phase, an oil phase and an aqueous phase. Figure 2B represents a configuration of the process with separation of a gas phase and a liquid water / oil phase. Figure 2C depicts a configuration of a process with separation of a gas-oil stream and an aqueous phase. The enclosed figure 3 is a schematic flow diagram of a third embodiment of the method of the present invention, in which the microwave radiation is applied only in the residual emulsion phase after a first stage of separation of water and oil . Figure 3A depicts a process configuration with three phase separation of a gas phase, an oil phase and an aqueous phase. Figure 3B represents a process configuration with separation of a gas phase and a water / oil liquid phase. Figure 3C depicts a process configuration with separation of a gas and oil stream from an aqueous phase.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For the purposes of the present invention, the term "Naphonic acids" means naphthonic or naphthene-aromatic carboxylic acids. The naphthenic acid specimens removed by the process of the invention are monophasic carboxylic acids of the general formula RCOOH, where R is a naphthenic segment. Naphthenic acids are predominantly formed compounds of alkyl substituted cycloaliphatic carboxylic acids, with minor proportions of non-cycloaliphatic acids. As minor components aromatic, olefinic, hydroxylic and dibasic acids may be present. The molecular weight of the naphthenic acids present in crude oils, determined by mass spectrometry, varies in the area between 200-700. The process for reducing naphthenic acidity of oils or their fractions according to the present invention is suitable for application in production facilities. In this case the oil already contains water, that is, production water and / or formation water. The procedure is equally suitable to be applied in refineries. The cargo to be treated according to the present process may contain solids of natural occurrence in this type of cargo and procedures. Typical solids are mud, sediment, sand, silica, coke, or corrosion residues. However, the addition of these solids will not be intentional. The oil reaches the refinery with approximately one percent emulsified water. This water has a certain amount of salts that is removed in the plant. desalination In the desalting plant a new amount of water is added to the emulsion / dispersion in diluted form in the concentration of the salts in the aqueous phase, this emulsion / dispersion being subjected to an electric field that causes the formation of a dipole in the droplets, favoring their coalescence and consequently their sedimentation. The water may be emulsified or dispersed in the charge. The water to form the emulsion can be effluent water from other processes, being able to have components such as ammonium, chlorides, sulfides, phenols and sodium hydroxide, with pH in the zone of 5-14, more preferably in the zone of 10-11. Water strongly absorbs radiation in the microwave spectrum, defined as the region of radiation that extends between 1000 MHz and 300,000 MHz. One way to check the capacity of adsorption of microwave radiation by a material is by checking its dielectric properties. The factor of dielectric loss (loss factor or loss tanget) provides a good indication of how much material can be penetrated by an electric field and dissipate this energy in the form of heat.

Studies showed that the presence of salts aids the absorption of microwave energy and facilitates the transformation of this energy into heat, since the loss factor of an aqueous solution at 5% NaCl is 6 times higher than the same factor for water pure In addition to this, as for pure water this factor decreases with the increase in temperature, it increases significantly when the water has a high content of salts. On the other hand, the oil absorbs to a very small extent the applied microwave radiation. The compounds that cause naphthenic acidity have surfactant characteristics, contributing to stabilize the emulsions. The migration of naphthonic acids and asphaltenes to the oil-water interface has been studied and often verified, according to an article by J. Sjóblom and others, "Our Current understanding of water-in-crude oil emulsions. pressure performance ". Advances in Colloid and Interface Science 100-102, 399-473 (2003). The film formed around the droplets of water dispersed in the oil is therefore rich in naphthenic acids and asphaltenes. The application of microwave radiation in emulsified water preferentially heats this water. According to the concept of the present invention, the naphthenic compounds that are found at the interface between the drop of water and the oil, receive the heat absorbed by the water in a localized manner, with the oil preferentially heating. The carboxylic acids, which cause naphthenic acidity, decompose at temperatures of around 320 ° C, generating CO2. The application of microwave radiation in a pressurized environment that can keep droplets in emulsion even at high temperatures allows the decomposition of carboxylic acid and the release of C02 reducing naphthenic acidity. Studies (Horeis and others, Fifth international Electronic Conference on Synthetic Organic Chemistry, 2001) showed that organic reactions can occur more rapidly when energy is used in the microwave zone than when heated by other means. The heating by microwave radiation is more uniform, not being influenced by the limitations of conduction or convection processes or by the high viscosity characteristics of the oil. According to the present invention, the oil charge contaminated with a concentration of naphthenic acids to be treated is a crude oil charge in the desalting or dehydration step or immediately before them. The hydrocarbon filler may be composed of oils, oil mixture, residual emulsions of other separation processes, process residues or mixtures thereof. Alternatively, the load is a fraction of oil, alone or in combination. Also alternatively, the filler is a mixture of petroleum or (mixtures) of petroleum with a petroleum fraction, alone or combined with other fractions. The concentration of naphthenic acids present in the oil charge emulsified with water and in the presence of salts can reach up to 10 mg KOH / g of oil. A typical zone is between 0.5 and 3 mg KOH / g of oil. The required power per gallon of oil to be treated is from 1 to 500 W. The process pressures are in the range of 0.7 to 4.5 MPa, which guarantees that the saline water does not pass into the gaseous state. Typical process temperatures are between 50 and 350 ° C. When a microwave emitter is comprised in a separation device, the residence times of the load to be treated are typically in the range of 20 seconds to 40 minutes. For an emitter of microwave radiation in line, that is, a microwave radiation emitter is an independent equipment of any phase separator, the residence time depends on certain parameters of the process such as flow rate of the load and diameter of the pipeline . When the process of the invention is applied to production facilities, there is no addition of water for the dilution of the concentration of salts, represented in the figures by the reference numbers (102), (202) and (302), nor is the mixing device (104), (204) provided. ) and (304) to form emulsified / dispersed water. Likewise, for the process in production facilities the load must be considered as being equivalent to the currents (105), (205) and (305). For the application of the procedure in refineries, the mixing device, which will be designated by the reference number (104), can be any device capable of causing swirls in the load. A typical mixing device is a valve. Another useful mixing device for this process is a static mixer. According to the embodiment of the present invention illustrated in Figure 1, the microwave radiation emitter is arranged in a device designated below by the reference number (106). This device is intended not only to subject a cargo of oil or its fractions to contact with microwave energy, but also to separate the water, oil and gas phases. The device (106) can be designed with various configurations, such as containers with internal coalescers or without these, depending on whether greater separation of the phases is desired. In this way, if there is no current downstream of the device (106) (Fig. 1A) other devices to aid phase separation, the device (106) must be provided therewith with means to facilitate phase separation, how to be coalescers. Alternatively other configurations are also possible, for example the presence of internal electrodes in the device (106) to generate an electrostatic field. The phase separation performed in the device (106) can be complemented downstream by centrifugation, gravity separation, ultrasound, hydrocyclones, electrostatic separation, filtration, membrane separation or combination of these techniques. Alternatively, the microwave radiation emitter is placed in line with the mixing equipment, according to the configuration of the process illustrated in Figure 2. According to what has been practiced in the art, the addition of the demulsifier is also part of the process of the invention. This addition can be made before, during or after the application of microwave radiation, in the step of phase separation. The microwave radiation is applied in the area of 1 rom to 30 cm at any oil load with water emulsified or dispersed in the presence of salts. Likewise, an oil load may originate from the fraction of petroleum or crude oil as produced in a production facility. The invention will be described below in more detail with reference to the accompanying figures. The flow diagram of Figure 1 schematically illustrates a first embodiment of the method of the invention, in which microwave radiation is applied during the step of phase separation. Figure 1A represents a configuration of the process with separation in a gas phase, an oil phase and in an aqueous phase in a single device designated with the reference number (106). Separation devices or separators useful for practicing the invention are three-phase or two-phase separators commonly used in the art. In FIG. 1A, the charging current (101) receives a stream (102) of water at a concentration of at least 3% v / v, with a typical zone comprised between 5 and 10% v / v, forming a current (103) conducted to the mixing device (104) in line, forming an emulsion / dispersion (105) of water and oil, which is conducted to the device (106) for the separation of the phases and which also contains a transmitter of microwave radiation from 1000 MHz to 300,000 MHz, heating the application of microwave radiation to water emulsified or preferentially dispersed this water, whereby the naphthenic compounds at the interface between the drop of water and the oil receive the heat absorbed by the water in a localized manner, preferentially heating the oil. The carboxylic acids, which cause naphthenic acidity, decompose at temperatures of around 320 ° C, generating C02. The application of microwave radiation in a pressurized environment that can keep the droplets in emulsion or dispersion without evaporating at high temperatures, allows the decomposition of the carboxylic acid and the release of C02, reducing the naphthenic acidity. The residence time in the device (106) is between 20 seconds and 40 minutes. In FIG. 1A, three-phase separation of the gaseous (107), organic (108) and aqueous (109) streams is carried out in the device (106). A current (107) represents a gaseous current rich in C02 generated by the degradation of the carboxylic acids present in the charge, in addition to light hydrocarbons. The stream (107) can be collected in a collector head common to the relief streams or any other destination. The stream (108) represents an organic stream of hydrocarbons with a concentration now reduced in naphthenic acids, that is, the desired product of treatment with microwave radiation. This stream may contain a smaller proportion of water, entrained solids and gases dissolved with C02. When the process is applied in the production stage, the stream (108) follows the conventional path of oil production. When either the process is used in refineries, the stream (108) continues for further fractionation. Both in the application in production plants, as well as in refineries, depending on the initial concentration of naphthenic acids in stream (101), the concentration of naphthenic acids remaining in the product stream (108) is analyzed. According to this remaining concentration, the possibility of a new naphthenic acid removal cycle can be considered. In the case of application in refineries, the current (108) can receive a new current of water equivalent to the current (102), with the same or a different percentage of water in relation to the load, being the water coming from it source or not, having in series a new mixing module, application of microwave radiation and phase separation. The processing conditions of this new cycle can be the same or different from those practiced in the first cycle, according to the necessary severity. It is also possible to consider a third stage of treatment, according to the concentration of salts or naphthenic acids initially present in the filler (101). It must be made clear that now the product stream (108) is represented as a lateral output of the device (106), the configuration adapted to this extraction being not critical and depending on the specific characteristics of the device (106). The stream (109) represents an aqueous stream leaving the device (106), constituted by water coming from the charging current (103), and may also contain a smaller proportion of hydrocarbons, entrained solids and dissolved gases such as C02. The stream (109) is conducted for disposal or recycled for the process. In Figure IB, the device (106 ') has two-phase separation. In this figure IB, the currents and devices (101) to (105) have the same meanings as in figure 1A. After subjecting the current (105) to the microwave radiation, the phase separation of the biphasic separation device (1061) is carried out as follows. The stream (110) represents a gaseous stream whose fate and composition are analogous to the gaseous stream (107). The stream (111) represents a liquid stream of hydrocarbons and water, which can also carry a smaller proportion of dissolved solids and gases. The current (111) is conducted to any separation device (112), wherein the separation takes place in an organic stream rich in hydrocarbons (113), product stream, and in an aqueous stream (114). The described procedures for these currents (108) and (109) can be applied in the same way to the currents (113) and (114). In Figure 1C, the device (106 ') has two-phase separation. In this figure 1C, the currents and devices (101) to (105) have the same meaning as in figures 1A and IB. After subjecting the current (105) to microwave radiation, phase separation is carried out in the biphasic separation device (106 ') as follows. The stream (115) represents an aqueous stream whose destination and composition are analogous to the aqueous stream (109). The stream (116) represents a stream of gas and hydrocarbons, which can also carry a smaller proportion of water. The stream (116) is conducted to any separation device (117), where it is separated into an organic stream rich in hydrocarbons (119), product stream, and a gaseous stream (118). The described procedures for currents (108) and (109) can also be applied to currents (119) and (115). In Figure 2 a second embodiment of the method of the invention is illustrated, wherein the microwave radiation emitter is placed in line, downstream of the mixing device and upstream of a separation device. Figure 2A depicts a process configuration with three phase separation of a gas phase, an oil phase and an aqueous phase. In Figure 2A the separation of a gas phase, an oil phase and an aqueous phase in a single device, designated by the reference number (208) takes place. In Figure 2A, the charging current (201) receives a stream (202) of water in concentration of at least 3% v / v, with a typical zone comprised between 5 and 20 v / v, forming a stream (203). ) conducted to the mixing device (204) in line, forming an emulsion / dispersion (205) of water in oil, conducted to the device (206) containing a microwave radiation emitter in the spectrum of 1000 Hz to 300,000 MHz, wherein the emulsion / dispersion water will be preferentially heated, whereby the naphthenic compounds at the interface between the water drop and the oil receive the heat adsorbed by the water in a localized manner, preferably heating the oil. The pressurized environment maintains droplets in emulsion / dispersion at high temperatures and allows the decomposition of carboxylic acid and the release of CO2, reducing naphthenic acidity. The stream (207) containing hydrocarbons with reduced concentration in naphthenic acids is then conducted to the three-phase separation device (208) for the separation of the respective phases. In FIG. 2 ?, the phase separation is similar to that described for FIG. 1A, the three-phase separation device with the reference number (208) being indicated, and representing the currents (209), (210) and (211) ) respectively a gas stream, a stream of hydrocarbons, a product that may contain a lower proportion of water, entrained solids and dissolved gases, such as CO2, and a stream consisting mainly of water, which may also contain a smaller proportion of hydrocarbons , entrained solids and dissolved gases as C02. Figure 2B represents a configuration of the process with a separation of a gas phase and a water / oil liquid phase. In Figure 2B, the device (208 ') has a two-phase separation. In this Figure 2B, the currents and devices (201) through (207) have the same meanings as Figure 2A. In the same way, the currents (212) and (213) correspond respectively to the currents (110) and (111) of the figure IB. A stream (213), rich in hydrocarbons and water, is conducted to any two-phase separation device (214), where it is separated into a current product (215) analogous to current (113), and in an aqueous stream (216) analogous to current (114). The procedures relating to one or more new treatment cycles for the reduction of the naphthenic acid concentration described for the currents (108) / (113) and (109) / (114) can also be applied to the currents (215) and (216). Figure 2C depicts a process configuration with a separation of a gas-oil stream and an aqueous phase. In this figure 2C, the currents and devices (201) to (207) have the same meanings as in figures 2A and 2B. From the two-phase separator (208 ') a gas and oil stream (218) analogous to the stream (116) of Figure 1C is obtained, said stream being directed towards a separator (219). The stream (217) represents an aqueous stream whose fate and composition are analogous to the aqueous stream (109) / (115). A liquid stream of hydrocarbons (218) can also carry a smaller proportion of water, solids and dissolved gases. The stream (218) is conducted to any separation device (219), where it is separated into an organic stream rich in hydrocarbons (221), product stream, and in a gaseous stream (220). The processes relating to one or more new treatment cycles for reducing the concentration of naphthenic acids described for streams (119) and (115) can be applied respectively to streams (221) and (217). In Figure 3 a third embodiment of the process of the invention is illustrated in which microwave radiation is applied only in the residual emulsion phase after a first stage of separation of water and oil. Figure 3A depicts a process configuration with three phase separation of a gas phase, an oil phase and an aqueous phase. According to FIG. 3A, a charging current (301) receives a stream (302) of water at a concentration of at least 3% v / v, with a typical area comprised between 5 and 10% v / v, forming a current (303) conducted to the mixing device (304) in line, forming an emulsion / dispersion (305) of water in oil, conducted to any phase separation device (306). In the device (306) are separated a stream (308) rich in water, which may contain a smaller proportion of solids and entrained hydrocarbons, a stream (307) of hydrocarbons that may contain a smaller proportion of water and entrained solids, and a stream (309) of residual emulsion, conducted to a device (310), three-phase separator that includes in its interior a microwave radiation emitter in the spectrum of 1000 MHz to 300,000 MHz, where the emulsion / dispersion water it will preferably be heated, during a residence time comprised between 20 seconds and 40 minutes, whereby the naphthonic compounds at the interface between the water drops and the oil receive the heat absorbed by the water in a localized manner, preferably heating the oil, maintaining the pressurized environment between 0.7 and 4.5 droplets in emulsion / dispersion at high temperatures and allowing the decomposition of carboxylic acid and at release of C02, reducing naphthenic acidity. The carboxylic acids that cause naphthenic acidity are decomposed by the action of microwave radiation, at temperatures of around 320 ° C, generating C02. After the necessary resistance time for the reduction of the concentration of naphthenic acids and the separation of phases in the device (310), a stream (312) of hydrocarbon product, and streams (311) and (313) analogous to the currents (107) and (109) of Figure 1A. Figure 3B presents a process configuration with separation of a gas phase and a water / oil liquid phase. In Figure 3B the currents (301) and (309) are as in Figure 3a. The separator (310 ') is a two-phase separator that includes a microwave radiation emitter. After subjecting the residual emulsion stream (309) to the microwave radiation for a necessary period, are obtained, analogously to the arrangement according to Figure IB, the gas streams (314), corresponding to the current (110), and (315), of hydrocarbon and water, analogous to the current (111). The stream (315) is nevertheless driven towards a separator (316) analogous to the separator (112). A stream (317) is the desired product stream, with hydrocarbons with reduced concentration in naphthenic acids and a stream (318) is an aqueous stream analogous to stream (114). The procedures relating to one or more new treatment cycles for reducing the concentration of naphthenic acids described for streams (113) and (114) can also be applied to streams (317) and (318). Figure 3C depicts a process configuration with separation of a gas and oil stream from an aqueous phase. In Figure 3C the streams (301) to (309) are as in Figures 3A and 3B. The residual emulsion stream (309) is conducted to the separator (310 ') which includes the microwave radiation emitter. After a necessary period in contact with the radiation and consequent reduction of the concentration of naphtanic acids, a separation takes place in an aqueous stream (319), the fate and composition of this stream being analogous to the aqueous streams (109) / (115). The current (320) represents a stream of gas and hydrocarbons, which can also carry a smaller proportion of water and solids. The current (320) is conducted to a device (321) of any separation, wherein an organic stream rich in hydrocarbons (323), product stream, and a gaseous stream (322) is separated. The procedures relating to one or more new treatment cycles to reduce the concentration of naphthenic acids described for currents (108) / (119) and (109) / (115) can also be applied to currents (323) and (319) ). An alternative process configuration for the present invention is one in which, due to the nature of the treated cargo or any other reasons, there is no need to have prevention for the separation of any gaseous phase. In this case, the separation devices used in the various configurations will be three-phase for the separation of the oil and water phases. As an advantageous derivation of the application of the present process of reduction of naphthenic acids of hydrocarbon loads, we can mention the minimization of the corrosion indices in the equipment with increased reliability and minimization of the risks associated with spills and / or emergency stops. . In addition to this, the process of the present invention decreases the consumption of chemical products for the control of pH and of corrosion inhibitors, as well as the risks inherent to this type of product and also does not require the use of any other raw material, involving the elimination of dangerous products. The oil with reduced concentration of naphthenic acids obtained by the process of the present invention allows its use with the purpose of dispensing with an adaptation of the metallurgical characteristics of the refining plant through the use of special materials of high cost. Having been the method of the present invention described more specifically in relation to the application in production and in refinery, it is obvious to the specialists that the inventive concept can also be applied to any industrial facility where it is desired to effect a reduction treatment of naphthenic acids in hydrocarbon loads.

Claims (49)

1. CLAIMS 1. Procedure for reducing the naphthenic acidity of oils or their fractions, characterized in that it comprises the operative stages of: a) providing a cargo of oil or its fractions with between 0.1 and 99% by weight of water emulsified / dispersed in the petroleum, said loading containing salts and a concentration of naphthenic acids measured as total acidity index between 0.1 and 10 mg KOH / g of petroleum; b) conducting the oil charge or its fractions with emulsified / dispersed water to a radiation emitting device in the microwave spectrum and subjecting said charge, in liquid phase, at a pressure comprised between 0.7 and 4.5 MPa, at temperatures between 50 ° C and 350 ° C, applying the microwave energy in the area of 1 mm to 30 cm to said oil load, so that the presence of salts, the applied temperature and the high dielectric constant of the droplets of water, they cause the heat to be absorbed by the water, in a localized way and that this heat preferentially to the oil, whereas the naffénicos compounds that are in the inferíase between the droplets and the oil, receive this heat; c) carry out the decomposition of the carboxylic acids that cause the naphthenic acidity in the oil charge or its fractions at temperatures around 320 ° C, generating C02; d) separating any generated gas, water and oil phase by means of any driven device; e) recover the oil with reduced concentration of naphthenic acids, where: i) the oil charge or its fractions is free of any added solid; ii) the migration tendency of naphthenic acids towards the emulsified phase, concentrating these acids in a fraction of the total charge, allows the microwave radiation to be applied to a fraction lower than the total load. Method according to claim 1, characterized in that the microwave radiation emitter is included in a phase separation device. Method according to claim 1, characterized in that the microwave radiation emitter is an independent device of any phase separator. Method according to claim 1, characterized in that in step d), the phase separation device separates only water and oil. Method according to claims 1 and 2, characterized in that it comprises the following operating steps: a) combining a charging current and a water stream in concentration of at least 3% v / v, forming a current conducted to a on-line mixing device, forming an emulsion / dispersion of water in oil conducted to a device, during a residence time comprised between 20 seconds and 40 minutes, at temperatures between 50 ° C and 350 ° C under pressure between 0, 7 and 4.5 Pa, in liquid phase, said device being for the separation of the phases and comprising a microwave radiation emitter from 1000 MHz to 300,000 MHz, heating the application of microwave radiation in water emulsified preferably to water, for which the naphthenic compounds that are found at the interface between the drops and the oil receive the heat absorbed by the water in a localized way. Preferably the oil is located; b) decompose by the action of microwave radiation the carboxylic acids that cause the naphthenic acidity, at temperatures around 320 ° C, generating C02; c) effect the separation of oil, gas and water currents; d) recovering the oil stream with reduced concentration of naphthenic acids, where: i) the hydrocarbon charge is free of any added solid; ii) the migration tendency of the naphthenic acids towards the emulsified phase, concentrating these acids in a fraction of the total charge, allows the microwave radiation to be applied in a fraction lower than the total load. 6. Method according to claim 5, characterized in that the device is a three-phase separator. 7. Process according to claim 6, characterized in that the separation produces a gaseous current rich in C02 generated by the degradation of the carboxylic acids present in the charge, in addition to light hydrocarbons. Method according to claim 6, characterized in that the separation produces a product stream, namely an organic stream of hydrocarbons with a reduced concentration of naphthenic acids. Method according to claim 6, characterized in that the stream is an aqueous stream conducted for its elimination or recycled for the process and is constituted by water coming from the charging stream, a smaller proportion of hydrocarbons, entrained solids and dissolved gases as C02 . Method according to claim 5, characterized in that alternatively the charging current is conducted to a two-phase separator generating a gaseous current and a stream of hydrocarbons and water, conducted to a second two-phase separation device in which a current of hydrocarbon product and an aqueous stream. 11. Method according to claim 5, characterized in that alternatively the charging current is conducted to a two-phase separator generating an aqueous stream and a stream of hydrocarbons and gas, conducted to a second two-phase separator where a gas stream and a current are separated. of hydrocarbons product. Method according to claims 5, 10 and 11, characterized in that alternatively the process load is the current. Method according to claims 1 to 3, characterized in that it comprises the following operative steps of: a) combining a charging current and a water stream in a concentration of at least 3% v / v, forming a current conducted to a online mixing device, forming an emulsion / dispersion of water in oil, conducted to a device containing a microwave radiation emitter in the spectrum of 1000 MHz to 300,000 Hz, the emulsion / dispersion water being preferentially heated, so which the naphthenic compounds found at the interface between the drops and the oil receive the heat absorbed by the water in a localized manner, preferentially heating to the oil, maintaining the pressurized environment between 0.7 and 4.5 MPa at temperatures between 50 ° C and 350 ° C the droplets in emulsion and allowing the decomposition of the carboxylic acid and the release of C02, reducing naphthenic acidity AC; b) decompose by the action of microwave radiation the carboxylic acids that cause the naffénica acidity, at temperatures around 320 ° C, generating CO2; c) separate oil, gas and water streams in phase separator; and d) recovering oil with reduced concentration of naphthenic acids, where: i) the hydrocarbon charge is free of any added solid; ii) the migration tendency of naphthenic acids towards the emulsified phase, concentrating these acids in a fraction of the total charge, allows the microwave radiation to be applied in a fraction lower than the total load. Method according to claims 3 and 13, characterized in that the residence time of the oil charge or its fractions in the microwave radiation emitter varies according to the flow rate or the diameter of the pipe. 15. Method according to claim 13, characterized in that the oil, gas and water streams are separated in a three-phase separator. 16. Process according to claim 13, characterized in that the separation produces a gaseous current rich in C02 generated by the degradation of the carboxylic acids present in the charge, in addition to light hydrocarbons. Process according to claim 13, characterized in that the separation produces a stream of product, namely an organic stream of hydrocarbons with a reduced concentration of naphthonic acids. Method according to claim 13, characterized in that the stream is an aqueous stream conducted for its elimination or recycled for the process and is constituted by water coming from the charging current, a smaller proportion of hydrocarbons, entrained solids and dissolved gases as CO2 . Method according to claim 13, characterized in that alternatively the charging current is conducted to a two-phase separator generating a gaseous current and a stream of hydrocarbons and water, conducted to a second two-phase separation device where a product hydrocarbon stream is separated. and an aqueous stream. Method according to claim 13, characterized in that alternatively a charging current is conducted to a two-phase separator generating an aqueous stream and a stream of hydrocarbons and gas conducted to a second two-phase separator where a gas stream and a stream of gas are separated. hydrocarbons product. 21. Method according to claims 13, 19 and 20, characterized in that alternatively the process load is a current. 22. Method according to claims 5 and 13, characterized in that in step c), the phase separation device separates only water and oil. Method according to claims 1 and 2, characterized in that it comprises the following operating steps: a) combining a charging current with a stream of water in concentration of at least 3% v / v, forming a current conducted to a device mixing in line, forming an emulsion / dispersion (305) of water in oil, conducted to any device for phase separation; b) separating in said device a water stream, a hydrocarbon stream and a residual emulsion stream; c) driving said residual emulsion stream towards a separating device, comprising within it a microwave radiation emitter in the spectrum of 1000 MHz to 300,000 MHz, the emulsion / dispersion water preferably being heated during a residence time between 20 seconds and 40 minutes, for which the naphthenic compounds found at the interface between the drops and the oil receive the heat absorbed by the water in a localized manner, preferentially heating the oil, the atmosphere being pressurized by 0.7 and 4.5 MPa and the temperature between 50 ° C and 350 ° C, keeping droplets in emulsion and allowing the decomposition of carboxylic acid and the release of CO2, reducing naphthenic acidity; d) decompose by the action of microwave radiation the carboxylic acids that cause naphthenic acidity, at temperatures around 320 ° C, generating CO2; e) separate the oil, gas and water streams in phase separator; and f) recovering oil with reduced concentration of naphthenic acids, where: i) the hydrocarbon charge is free of any added solid; ii) the migration tendency of naphthenic acids towards the emulsified phase, concentrating these acids in a fraction of the total charge, allows the microwave radiation to be applied in a fraction lower than the total load. Method according to claims 2, 5 and 23, characterized in that the residence time of the oil charge or its fractions in the microwave radiation emitter varies between 20 seconds and 40 minutes. Method according to claims 5, 13 and 23, characterized in that the concentration of water of the stream / (202) / (302) combined to the stream / (201) / (301) is comprised between 5 and 10% v / v. 26. Process according to claim 23, characterized in that the separation produces a gaseous current rich in C02 generated by the degradation of the carboxylic acids present in the charge, in addition to light hydrocarbons. Method according to claim 23, characterized in that the separation produces a product stream, namely an organic stream of hydrocarbons with a reduced concentration of naphtanic acids. Process according to claim 23, characterized in that the stream is an aqueous stream conducted towards its elimination or recycled for the process and is constituted by water coming from charge current, a smaller proportion of hydrocarbons, entrained solids and gases dissolved as CO2. 29. Method according to claim 23, characterized in that alternatively the residual emulsion stream is conducted to a two-phase separator generating a gaseous current and a stream of hydrocarbons and water, conducted to a second biphasic separation device in which a current of hydrocarbon product and an aqueous stream. 30. Method according to claim 23, characterized in that alternatively the residual emulsion stream is conducted to a two-phase separator generating an aqueous stream and a hydrocarbon and gas stream, conducted to a second two-phase separator where a gas stream and a gas stream are separated. hydrocarbon product stream. 31. Method according to claims 23, 29 and 30, characterized in that alternatively the process load is a current. 32. Method according to claim 23, characterized in that in step d), the phase separation device separates only water and oil. 33. Process according to claims 1, 5, 13 and 23, characterized in that the pH of the water emulsified / dispersed in the oil charge or its fractions is between 5 and 14. 34. Method according to claim 33, characterized in that the pH of the water emulsified / dispersed in the oil charge or its fraction is between 10 and 11. 35. Process according to claims 33 and 34, characterized in that additionally the water emulsified / dispersed in the oil charge or its fractions contain phenols, chlorides , sulfur, ammonium hydroxide and sodium hydroxide. 36. Method according to claims 1, 5, 13 and 23, characterized in that it is applied in the production of petroleum. 37. Method according to claims 1, 5, 13 and 23, characterized in that it is applied in refineries. 38. Method according to claims 1, 5, 13 and 23, characterized in that it is applied in any industrial installation. - 39. Method according to claims 1, 5, 13 and 23, characterized in that the oil charge or its fractions is a load of crude oil or a mixture of oils. 40. Method according to claims 1, 5, 13 and 23, characterized in that the oil charge or its fractions is an oil cut, alone or combined with other cuts. 41. Method according to claims 1, 5, 13 and 23, characterized in that the oil charge or its fractions is a load of crude oil or a mixture of oils combined with an oil cut alone or combined with other cuts. 42. Process according to claims 1, 5, 13 and 23, characterized in that the oil charge or its fractions is a petroleum processing residue. 43. Method according to claims 1, 5, 13 and 23, characterized in that the concentration of naphthonic acid of the load measured as the total acid value is between 0.5 and 3 mg OH / g of oil. 44. Process according to claims 1, 5, 13 and 23, characterized in that it additionally includes a demulsifier. 45. Method according to claim 44, characterized in that the demulsifying addition is carried out before, during or after the application of microwave radiation, in the stage of separation of the phases. 46. Process according to claims 1, 5, 13 and 23, characterized in that additionally the product of hydrocarbons with reduced concentration of naphthenic acids is analyzed for the determination of the remaining naphthenic acid concentration. 47. Process according to claim 46, characterized in that for naphthenic acid concentrations in the product stream higher than the desired, a new naphthenic acid removal cycle is carried out, for which the hydrocarbon stream can receive a new water current equivalent to the initial current used to prepare the emulsion / dispersion, with the same or with different percentage of water in relation to the load, providing the water from the same source or not, so as to form a new cycle of mixing process, application of microwave radiation and phase separation. 48. Method according to claim 47, characterized in that the process conditions of said new cycle can be the same or different from those practiced in the first cycle, according to the necessary severity. 49. Method according to claims 1, 5, 13 and 23, characterized in that the phase separation carried out in the phase separation device is completed downstream by centrifugation, separation by gravity, ultrasound, hydrocyclones, electrostatic separation, filtration, membrane separation. or combination of these techniques. SUMMARY A method is described for reducing the naphthenic acidity of oils or their fractions comprising providing a load (103) / (203) / (303) of hydrocarbons with between 0.1 and 99% by weight of water emulsified / dispersed in petroleum , said loading containing salts and a concentration of naphthenic acids measured as total acidity index, comprised between 0.1 and 10 mg KOH / g of petroleum, driving the oil charge with emulsified / dispersed water towards an energy emitting device in the microwave area and submit said load (103) / (203) / (303), in liquid phase, under pressure between 0.7 and 4.5 Pa, at temperatures between 50 ° C and 350 ° C to microwave radiation , applied in the area of 1 mm to 330 cm in the load, so that the presence of salts, the temperature applied and the high dielectric constant of the water droplets, cause the heat to be absorbed by the water in a localized manner and that it preferentially heat oil, while after the naphthenic compounds, which are at the interface between the droplets and the oil, receive this heat; effect the decomposition of the carboxylic acids that cause the naphthenic acidity in the oil charge at temperatures around 320 ° C, generating C02; separate by any known device (106) / (106") / (112) / (117) / (208) / (208 ') / (214) / (219) / (310) / (310') / (316) / (321) any generated gas phase, water and oil, and recover the flow of oil (108) / (113) / (119) / (210) / (215) / (221) / (312) / (317) / (323) with reduced concentration of naphthonic acids. The procedure is applied for the reduction of naphthenic acids in petroleum charges or their fractions in the oil production phase, in refineries or in any industrial facility.