EP3601487A1

EP3601487A1 - Method and purifying device for removing alkali, alkaline earth, and heavy metals from crude and heavy oils

Info

Publication number: EP3601487A1
Application number: EP18730248.4A
Authority: EP
Inventors: Markus Kinzl; Ansgar Kursawe
Original assignee: Siemens AG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2017-06-06
Filing date: 2018-05-23
Publication date: 2020-02-05
Also published as: WO2018224310A1

Abstract

The invention relates to a method and a purifying device for largely removing alkali, alkaline earth and heavy metals from crude or heavy oil (1). In the method, a largely or completely metal-free water (2) and an anti-solvent (3) are first added to the crude or heavy oil (1) and the resultant mixture is mixed in a mixing unit (A) in such a way that a multi-phase mixture (4, 4') is produced. In the multi-phase mixture (4, 4'), the water-soluble alkali and alkaline earth metals dissolve from the crude or heavy oil (1) in the form of their salts in the phase of the metal-free water (2), and water-insoluble heavy metals precipitate from the crude or heavy oil (1) by deasphalting with the anti-solvent (3) in the form of suspended asphalt particles. The multi-phase mixture (4, 4') is separated, by phase separation in a processing stage (F), into purified crude or heavy oil (100), which is desalinated and largely free from alkali, alkaline earth and heavy metals, into water (300), which is rich in alkali, alkaline earth and heavy metals, and into suspended asphalt particles (400) rich in heavy metals. According to the invention, the suspended asphalt particles obtained in the method are fed back by a return line (5) into the crude or heavy oil (1) in the region where the anti-solvent (3) is added.

Description

description

Process and cleaning device for removing alkali, alkaline earth and heavy metals from crude and heavy oils

Raw and heavy oils are only of limited use for power generation in gas turbines, since modern gas-cooled high-performance gas turbines, such as the H-class, only low concentrations of heavy metals, especially nickel and vanadium, and alkali and alkaline earth metals (eg sodium and potassium) tolerate in the fuel. For high-performance turbines, the upper concentration limit for the said heavy metals is in the range of 0.5 ppm. However, standard gas turbines, such as the E-Class, tolerate higher levels of heavy metals (floating limit up to 100 ppm), but an additive (magnesium salts) must be added to suppress the corrosive effects of heavy metals. These additives in turn lead to an increased service effort, since they form crusts together with the heavy metals and these must be removed regularly from the turbine blades during a shutdown.

The upper limits for alkali and alkaline earth metals are in the range of less than or equal to 0.5 ppm for all gas turbine classes. As raw and heavy oils typically significantly higher

Concentrations of heavy metals and alkali and alkaline earth metals, a reduction of these impurities is necessary to make the oils for gasification in gas turbines operational or to reduce the service cost and need for inhibitors in the operation of standard turbines. While alkali and alkaline earth metals are water-soluble and thus can be washed out by washing with water, a reduction of the heavy metal concentrations due to the lack of water solubility of the heavy metal compounds contained in the oil can not be achieved by this simple method. Already known are processes for deasphalting for the removal of heavy metals from crude and heavy oils.

From the prior art methods are known which describe a combination of desalination by water washing and deasphalting. However, the methods presented have clear disadvantages:

Patents GB 2145730 and FR 2550545 describe a process in which water and an anti-solvent (deasphalting agent) are added to the oil. As anti-solvent typically short-chain alkanes are used. After mixing the components, a phase separation takes place in a separator to form three phases: an oil phase consisting of the deasphalted oil and the antisolvent, an asphaltene phase and a water phase in which the alkali metal and alkaline earth metal salts removed from the oil are in dissolved form , To improve the phase separation of the mixture before entering the phase separator a

Deemulsifier be added.

Two disadvantages of the described method are immediately apparent: First, it comes immediately after mixing of oil, anti-solvent and water for phase separation, since the mixture is passed directly into the phase separator. There is no mixed residence container is provided in which the phases would be finely dispersed, a large exchange area for the mass transfer would be given and the deasphalting and desalination before the onset of phase separation could be given sufficient time. Our own investigations have shown that at least the deasphalting requires residence times in the range of a few minutes. This residence time depends on the respective substance system and can vary within certain limits. The disadvantage is that this process must be carried out in several successive process steps. The second drawback is that deasphalting leads to fouling because the asphaltenes that separate are attached to available surfaces, eg pipe or container surfaces. In the cited prior art asphalt particles are formed only by the addition of antisolvent and precipitation.

The patent US 2010/0089797 describes an "at least partial" deasphalting, by the taking place in the context of a water wash addition of water to raw or

Heavy oils is released. Addition of an additional anti-solvent is not disclosed here. It is described that after emulsification of water and oil, a phase separation is carried out to obtain a water phase containing the leached alkali metal and alkaline earth metal salts, a deasphalted oil phase and an asphaltene phase. These phases can then be separated. The process has significant disadvantages:

Although it is known from the patent RU 2000312, for example, that water added to the oil has a positive effect on deasphalting, because the strongly polar water attaches to the slightly polar surface of the asphaltenes and thus additionally polarizes this surface, so that the

Asphaltene solubility in non-polar oil is reduced. Our own investigations have shown, however, that no appreciable asphaltene separation from oils can be detected if no anti-solvent is added.

Although oils can be used in conventional standard gas turbines after water washing / desalination, it is always necessary to add inhibitors, since these oils still contain high concentrations of vanadium and nickel. A sufficient heavy metal separation by

Deasphalting always requires the addition of an anti-solvent. Added water can only yield the deasphalting yield and possibly the morphology of the asphalt Particles improve, which proves to be advantageous in the subsequent solid-liquid separation.

The patent specification US 2010/0089797 describes a deasphalting process. However, the fouling problem can also be expected in this deasphalting process, because at the moment of supersaturation, no surface other than that of the pipes or containers together with internals is available. The object of this invention is to provide a cost effective method and apparatus by which the depletion of both the water-soluble and the water-insoluble impurities, especially alkali, alkaline earth and heavy metals from crude or heavy oil, can be carried out efficiently. The known from the prior art disadvantages, especially fouling should be avoided.

The object of the invention is achieved by the independent device claim and the independent method claim.

The directed to a method object of the invention for the substantial removal of alkali, alkaline earth and heavy metals from crude or heavy oil is achieved by the independent method claim 1. Here, the raw or heavy oil, a largely or completely metal-free water and an antisolvent is added and the resulting mixture in a mixing unit mixed together such that a multi-phase mixture is formed. In the multiphase mixture, the water-soluble alkali metals and alkaline earth metals are dissolved from the crude or heavy oil in the form of their salts in the phase of the metal-free water, and water-insoluble heavy metals from the crude or heavy oil fall through

Deasphalting with the antisolvent in the form of suspended asphalt particles. The multiphase mixture is purified by phase separation in a working up step

Raw or heavy oil, which is desalted and substantially free of alkali, alkaline earth and heavy metals, in alkaline and alkaline earth metal-rich water, and in heavy metal-rich, suspended _.

suspended asphalt particles separated. According to the invention, the suspended asphalt particles obtained in the process are recycled through a return line into the crude oil or heavy oil in the area at which the antisolvent is added.

An essential aspect of the invention is that the crude or heavy oil desalted by water washing and simultaneously by

Deasphalting is depleted in heavy metals.

For this purpose, in addition to the crude or heavy oil, alkali metal and alkaline earth metal-free or water-free water and an antisolvent are added to the process. The products obtained are heavy metal-rich asphalt particles, alkaline and alkaline earth metal-rich water and purified oil, whereby at least one oil product stream is obtained which has reduced heavy metal concentrations and can therefore be used advantageously in vanadium-tolerant standard turbines. In a particular embodiment, another oil product stream can be obtained which has greatly reduced heavy metal concentrations in the range of less than or equal to 0.5 ppm so that it can be used in heavy metal sensitive high performance turbines. The product oils have been greatly depleted of alkali and alkaline earth metals, so that the remaining residual concentrations of these components do not limit the use in gas turbines.

The core of the invention is that already suspended asphalt particles are present at the point where the antisolvent is added to the crude or heavy oil. For this purpose, suspended asphalt particles are recycled to the crude or heavy oil which had previously been formed by the continuous process. As a result, the deasphalting step is not affected by fouling. To prevent fouling, the crude or heavy oil to be deasphalted and the antisolvent are intensively mixed with the aid of a mixing unit (eg a pump). With the help of a recycle stream of suspended asphalt particles is ensured that in place the supersaturation already solid asphalt particles are available on the surface of which can be deposited from the oil asphaltenes. The unwanted growth on pipe and container surfaces (fouling) which frequently occurs in conventional deasphalting is thus prevented. According to the invention, suspended asphalt particles are used, and no dry-solid particles.

The task of reducing the concentrations of alkali, alkaline earth and heavy metals in crude and heavy oils before the oils are used as gas turbine fuels is achieved by a combination of water washing (desalination) and deasphalting. The water wash removes the water-soluble alkali and alkaline earth metals in the form of their salts, while the water-insoluble heavy metals are separated together with the asphaltenes in which they occur in very high concentrations (deasphalting). The two

Washing processes complement each other. Both of them are necessary because heavy metals can not be removed by dewaxing from oils with water washes and alkali / alkaline earth metals.

The combined crude oil purification allows the use of crude and heavy oils as gas turbine fuels. Highly contaminated raw or heavy oils, which may not be used in the uncleaned state due to their high concentrations of corrosive metals or metal salts, are made usable by cleaning, and crude or heavy oils, which may be used only with high service costs, after Cleaning be emitted at significantly reduced operating costs.

Preferably, the multiphase mixture is maintained in intimate phase contact for a period of time prior to being phase separated until equilibration by bulk transport operations is about 95% complete. This will ensure that the concentration of heavy metals is in the range of less than 0.5 ppm and the alkali, alkaline earth metals have almost completely transferred into the aqueous phase.

In a particularly advantageous embodiment, desalting and deasphalting are carried out together in one step. In this case, the multiphase mixture is passed before the phase separation in a mixing unit downstream of the container, wherein a partial flow of the multiphase mixture with suspended asphalt particles from the container into the

Mixing unit is returned. The wash water is thus present in the deasphalting, which has a positive side effect: the expert is aware that the oil added to water positively influences deasphalting, because the highly polar water attaches to the slightly polar surface of the asphaltenes and thus polarized this surface additionally, so that the asphaltene solubility in the non-polar oil is reduced. As a result, the deasphalting yield can increase and the particle properties can be improved, resulting in improved separation in the subsequent solid-liquid separation. In addition, this integrated process saves a mixing stage for the combination of oil and water compared to the sequential variants, since the mixing devices (mixing pump and mixing tank) already present in the deasphalting stage can be used.

In those cases in which the deasphalting occurs spontaneously and no appreciable residence time is required, can be dispensed with the mixing vessel. The mixing function is then completely taken over by the mixing device. The separation of the desalted and deasphalted oil from the asphalt particles and the salt-laden water is carried out by phase separation in a work-up stage (separator), wherein the phase with the oil antisolvent with residues of asphalt particles and salt-laden water is fed to a separator in which the light oil antisolvent phase is separated from heavy components from the oil antisolvent phase. The phase of suspended asphalt particles is fed to a solid-liquid separation stage in which the asphalt particles are separated from their mother liquor.

The levels of the separate phases in the separator are controlled by suitable sensors to ensure that the discharges are each fed with the correct phase. Alternatively, the separation of the phases can take place in successive stages of separation. In a further advantageous further development of the method according to the invention, the mixing unit is preceded by a water wash device and a phase separator, wherein the crude or heavy oil and the largely or completely metal-free water are fed to the water wash device and mixed with each other to form an emulsion which is fed to the phase separator , In the phase separator, a phase of salt-laden water is separated, and a residual phase of desalted oil is fed to the mixing unit together with the antisolvent.

Preferably, the raw or heavy oil is supplied to a concentration stage before being fed into the water wash device, in which it is concentrated by evaporation and / or distillation, wherein volatile components are separated off. By the possibility of the vaporizable

Extracting crude oil components prior to the purification steps and thus recovering high-purity distillate, a large part of the crude oil can be obtained as a fuel for heavy metal-sensitive high-performance turbines. The remaining portion is fed to the purification steps described above and thus prepared for the power generation in heavy metal tolerant standard turbines, which can now be done with greater efficiency. The asphalt particles separated in all variants are also a valuable product of the process. These can be supplied to the production of road asphalt or electricity in thermal power plants. In order to bring about an improvement in the separation of the asphalt particles formed during the deasphalting, one or more additives can advantageously be added. The additives may be added before the mixing unit, and / or in the mixing unit, and / or in the circuit between mixing unit and phase separator. Alternatively or additionally, the additives may also be added in the container, and / or in the circuit between the mixing unit and the container. Advantageously suitable as additives are phosphoric acid and / or phosphorous acid.

The ratio between the crude or heavy oil (1) and the water (2) is preferably set in a range of 5: 1 and 50: 1. Further advantageous is a ratio of 10: 1.

In a further advantageous development, a de-emulsifier is added to the emulsion to improve the phase separations carried out in the phase separator.

In a particular embodiment of the invention, the three-phase mixture is divided into at least a first and a second product stream and separated. The first product stream is depleted in heavy metals to such an extent that it has vanadium and / or nickel concentrations of less than or equal to 0.5 ppm, and can be sent to a high performance gas turbine for combustion. The second product stream is only lightly stored on heavy metals, so it has a concentration of vanadium and / or nickel of more than 0.5 ppm, and can be fed to a standard gas turbine for combustion. In both cases, the product oils have been strongly depleted of alkali and alkaline earth metals, so that the remaining residual concentrations of these components do not limit the use in gas turbines.

The device-oriented object of the invention for the substantial removal of alkali, alkaline-earth and heavy metals. from crude and heavy oils is dissolved by a cleaning device with a mixing unit and a treatment stage. In this case, the crude or heavy oil, a largely or completely metal-free water and an antisolvent fed, and mixed in the mixing unit together to form a multi-phase mixture, that in the multiphase mixture, the water-soluble alkali and alkaline earth metals from the crude or heavy oil in Dissolve the form of their salts in the phase of the metal-free water, and precipitate water-insoluble heavy metals from the crude or heavy oil by deasphalting with the antisolvent in the form of suspended asphalt particles. In the work-up stage, the multiphase mixture can be separated into a purified crude or heavy oil, which is desalted and largely freed of alkali metals, alkaline earth metals and heavy metals, an alkali and alkaline earth metal-rich water and heavy metal-rich asphalt particles. According to the invention, the suspended asphalt particles obtained in the cleaning apparatus are returned to the crude oil or heavy oil by means of a return line, in the area where the antisolvent is located

can be fed, traceable.

The advantages of the cleaning device according to the invention are analogous to the method according to the invention.

In a further development of the cleaning device, the multiphase mixture is in intimate phase contact in a residence time before the processing step until the equilibration by material transport operations in about 95% is completed.

In a further advantageous further development of the cleaning device, a container is provided between the work-up stage and the mixing unit, the container being connected to the mixing unit by the return line, so that a partial stream of the multiphase mixture with suspended acids phalt particles from the container in the mixing unit is traceable.

Preferably, the work-up stage is followed by a separator and a solid-liquid separation stage, wherein the phase with the oil-antisolvent with residues of asphalt particles and salt-laden water can be fed to the separator, in which the light oil antisolvent phase of heavy Components from the light oil antisolvent phase is separated,

and the phase of suspended asphalt particles is deliverable to the solid-liquid separation stage where asphalt particles (400) are separated from their mother liquor.

Further advantageously, the water wash device is a

Upstream concentration level, the raw or

Heavy oil can be fed so that volatile components can be separated by evaporation and / or distillation and thus the crude or heavy oil can be concentrated. Advantageously, the mixing unit and / or in the

Mixing unit and / or in the circuit between the mixing unit and phase separator one or more additives can be introduced, which bring about an improvement in the separation of the asphalt particles formed in the deasphalting. Alternatively or in addition thereto, additives can be introduced into the container and / or in the circuit between the mixing unit and the container. As additives, phosphoric acid and / or phosphorous acid are preferably added. Advantageously, a ratio between the crude or heavy oil and the water is set between 5: 1 and 50: 1. Preferably, the ratio is about 10: 1.

In a further improvement of the cleaning device, a de-emulsifier can be added to improve the phase separations of the emulsion carried out in the phase separator. In a further development of the cleaning device, the crude oil can be separated off at least into a first and a second product stream. The first product stream is heavily depleted in heavy metals, so it has vanadium and / or nickel concentrations of less than or equal to 0.5 ppm, and is combustible in a high-performance gas turbine. The second product stream is only lightly stored on heavy metals, and has a vanadium and / or nickel concentration of greater than 0.5 ppm, and is combustible in a standard gas turbine.

In the following the invention will be explained in more detail with reference to figures. 1 shows a circuit diagram of the invention with the educt and

Product streams;

FIG. 2 shows a first embodiment of the invention with sequentially sequential process steps;

FIG. 3 shows a second embodiment of the invention with sequentially sequential process steps with concentration stage;

FIG. 4 shows a further embodiment of the invention with integrated method steps;

5 shows a further, simplified embodiment of the invention with integrated method steps.

Figure 1 shows a schematic diagram of the process according to the invention with the educt and product streams of the process. The cleaning device H, a crude or heavy oil 1, a substantially or completely metal-free water 2 and an anti-solvent 3 are added. The antisolvent does not need to be added separately because it is generated within the cleaning device H. The purifier leaves a purified crude oil or heavy oil 100, volatile components 200, salt laden wastewater 300 and an asphalt particle end product 400.

For the invention is essential that the place of the

Asphalt particles are already available as asphalt particles, so that no fouling occurs due to asphaltenes precipitating from the oil, which could deposit on pipe or container walls in the absence of particles.

The stream of purified crude oil or heavy oil 100 may be fed to gas turbines and thus used for the production of electric power, while the asphalt particles 400 are sent for recovery (production of road asphalt or power generation in thermal power plants) and the salt laden wastewater 300 (aqueous salt solution) is subjected to a wastewater treatment.

The processes for the purification of crude and heavy oil 1 can be subdivided into two groups. On the one hand a sequential execution of water washing and deasphalting and on the other hand an integrated execution of these purification steps.

FIG. 2 shows a first embodiment of the invention, with process steps taking place sequentially one behind the other. In the sequential process, the water washing for oil desalting and the deasphalting take place in succession in separate steps. The water 2 added to the oil wash, which extracts the alkali metal and alkaline earth metal salts from the oil, is again separated in a stream 300 before deasphalting occurs.

A line, with a stream of crude or heavy oil 1, is supplied without prior concentration of a water purifier T2. The water purifier T2 is a mixed unit, in which the crude or heavy oil 1 is mixed with a stream of substantially or completely metal-free water 2, wherein a water-in-oil emulsion 1 'is formed. The ratio between the crude or heavy oil and the water 2 is about 10: 1. Due to the fine distribution of the phases insoluble in one another (emulsification), a large phase interface is generated, via which all water-soluble salts, in particular alkali metal and alkaline earth metal salts, are wholly or partially extracted from the oil into the water. From the water scrubber T2, the water-in-oil emulsion 1 'is fed to a phase separator T3 which separates the phases to form a salt laden waste water 300 and a desalted oil 1 " The desalted oil is fed to a mixing unit A in power plants.

To improve the phase separations carried out in the phase separator T3, a de-emulsifier can be added to the emulsion 1 '. As long as the phases are thoroughly mixed in the mixing unit T2, the phases do not yet separate macroscopically. These remain in the emulsified state, which allows an intensive mass transfer over the large phase interface. As soon as mixing energy is no longer introduced and instead there are conditions which favor phase separation in the phase separator T3, the action of the de-emulsifier prevails, whereby the phases separate out. The mixing unit A is next to the desalted oil 1 "a

Antisolvent 3 stream and a stream of 5 recycled asphalt particles recycled. The liquids are mixed. Antisolvent 3 is a solvent which has already been recovered from crude or heavy oil 1 within the process. The desalted oil 1 ", the antisolvent 3 and the stream 5 are intensively mixed by the mixing unit A (eg a mixing pump) using a mixture 4 of desalted oil, antisolvent and asphalt particles arises. Mixture 4 is fed to vessel B, where a residence time is provided for the deasphalting initiated by the addition of anti-solvent 3. Due to the residence time, the de-Asphaltierung begins, which forms a mixture of crude or heavy oil 1, antisolvent 3 and already failed asphalt particles.

A part of the present mixture is fed to the mixing unit A in the form of a backflow 5, so that there are suspended asphalt particles at the point of mixing, at which the asphalts precipitating from the supplied desalted oil 1 "can grow up, whereby the fouling becomes successful The container B leaves a stream of the mixture 6 at the top and a stream of the mixture 9 at the bottom.

The stream with the mixture 6 is fed to a separator C in which there is a phase separation based on density differences. Optionally, the phase separation can be enhanced by centrifugal action (hydrocyclone). In this case, a light, depleted of asphalt particles oil antisolvent phase 100 'is separated, which is fed to the antisolvent recovery. The antisolvent recovery can be carried out advantageously by distillation.

The purified crude or heavy oil 100 remaining in the anti-solvent recovery, which still contains heavy metal residues (the concentrations are, however, in the tolerable range) can now be supplied as a product of a standard turbine. Separator C also produces a mixture 7 of concentrated, solid asphalt particles in a 01 antisolvent mixture, which is recycled in a stream into container B.

The withdrawn from the container B stream with the mixture 9 is fed to the separator E. The function of the separator E is likewise based on a density-dependent separation, which can be partially reinforced by centrifugal action (eg hydrocyclone). In the container E, a light oil anti-solvent phase 8 is formed, which is returned to the container B. The solid asphalt particle enriched phase 10 is fed as a stream to the solid-liquid separation stage G, where the solid asphalt particles are separated from adherent mother liquor 14. The liquid phase 14 is returned to the container B. The asphalt particles 400 recovered in the solid-liquid separation step G and the above-mentioned sewage 300 are end products of the process, the oil antisolvent stream 100 'may be supplied for anti-solvent recovery. The purified crude or heavy oil 100 remaining after separation of the antisolvent is supplied as power to a standard turbine.

Figure 3 shows a second embodiment of the invention with sequential successive process steps with an additional concentration level.

This further development of the invention is based on the embodiment of FIG. 2. According to the further development in FIG. 3, a concentration stage T1 is connected in the pipeline for crude oil or heavy oil 1, by means of which readily volatile components from the crude or heavy oil 2 are introduced Concentrate can be deducted. The concentration stage T1 is preferably carried out in the form of an evaporation and / or distillation. In the embodiment shown in FIG. 3, the asphalt particles 400 and the above-mentioned waste water 300 obtained from the solid-liquid separation stage G are obtained as end products of the process, while the oil anti-solvent stream 100 'is supplied to the anti-solvent recovery in which the antisolvent is recovered to be re-deasphalted into the mixing unit A after mixing with the C4-C6 low boilers. The after separation of the anti-insulating remaining purified crude or heavy oil 100 is supplied as power to a standard turbine.

In the concentration stage T1, the crude or heavy oil 1 is deprived of the readily volatile components (low-boiling components, typically C4-C6 components) before washing the water in the water-washing device T2. This is preferably done by a distillation process, which is not shown in the figure. These low boilers are combined with the distillate stream obtained in the later antisolvent recovery and then used as an anti-solvent in the deasphalting by being fed as anti-solvent 3 to the mixing unit A. The concentration stage T1 leaves a stream of vaporized, volatile components 200 which are virtually metal-free and can be delivered to heavy metal sensitive high performance gas turbines. The sequential methods have the advantage that no three-phase mixtures occur, whereby the phase separation is facilitated. For the water washing step, standard apparatuses available on the market can be used. On the other hand, however, the positive effect of water on deasphalting, which is an advantage of the integrated process, is eliminated.

FIG. 4 shows a further embodiment of the invention with integrated method steps. In the integrated process, in contrast to the sequential processes, water is present during the deasphalting process.

The stream shown in FIG. 4 with crude oil or heavy oil 1 may already have been advantageously concentrated by prior withdrawal of the volatile components in a concentration stage (not shown here). One used here

Concentration level is similar to the

Concentration stage Tl, which in the sequential method of Figure 3 is shown. The low boilers (typically C4 -C6 components) obtained in this concentration step, together with the distillate stream obtained in the antisolvent recovery, are used as antisolvents for the

Deasphalting used. The higher boiling point components that are also vaporized are virtually metal-free and can be delivered as a stream of volatile components 200 for use in high-performance turbines. A mixing unit A becomes a stream of crude or heavy oil

1, a stream of substantially or completely metal-free water 2, and a stream of antisolvent 3 supplied, the Antisolvent 3 as described above, is recovered within the process of the crude oil. The streams fed to the mixing unit A are intensively mixed, whereby a fine distribution of the components results and a large phase boundary is created for the mass transfer necessary in water washing and deasphalting. The resulting three-phase mixture 4 'is fed to the intensively mixed container B, where residence time is provided for the two purification processes without the phases separating from each other. The resulting deasphalting (separation of solid asphalt particles) is favorably influenced by the presence of water, while at the same time the desalting of the oil takes place by a migration of the water-soluble salts into the water phase. A portion of the present emulsion, which now contains suspended asphalt particles, is fed to the mixing unit A in the form of a recycle stream 5. Thus, at the point of supersaturation, there are still solid asphaltene particles at which the fresh asphaltenes precipitated from the supplied oil 1 can grow up. This successfully prevents fouling.

Analogous to the embodiment of the invention described in FIGS. 2 and 3, a stream of a mixture 6 is fed to the separator C. Separation according to density takes place in the separator, for example by a phase separation based on density differences, which is produced by centrifugal action. can be strengthened (hydrocyclone). In this case, a light oil antisolvent phase 100 'is separated off, which is fed as a stream of antisolvent recovery (advantageously by distillation). The resulting in separator C heavy mixture 7 with concentrated solid asphalt particles is returned to the container B.

Furthermore, a stream 9 is withdrawn from the container B with solid asphalt particles, which consists of a light oil antisolvent phase and the water phase containing the water-soluble salts. The stream 9 of solid asphalt particles is fed to the separator E, whose function is also based on a separation by density, which can be enhanced by centrifugal action (hydrocyclone). A light oil antisolvent phase 8 is returned to the container B, while a heavy phase with water and asphalt - particles with remaining residues of the oil antisolvent phase as mixture 10/13 fed to a solid-liquid separation stage G for further processing becomes.

This can be done in a three-phase separator. The three phases (solid asphalt particles, oil with antisolvent and water) are advantageously finally separated from each other in a single workup stage F. In the three-phase separator F, residues of the light oil antisolvent phase, which is not completely separated in the separator E, separate out as the upper phase. Furthermore, a water phase is formed, which contains the water-soluble salts, which were previously washed out of the oil, as well as the phase of the water-and oil-insoluble asphalt particles.

The water phase 300 is supplied as a stream of wastewater treatment while the still oil wet asphalt particles 15 are supplied as a stream to the solid-liquid separation stage G, where the solid asphalt particles are separated from adherent mother liquor 14, which is again fed to the phase separation stage F. , The levels of the three mentioned in the separator phases are controlled by suitable sensors, for example, based on conductivity, so that it is ensured that the derivatives are each fed with the correct phase. The oil antisolvent phase formed in the separator F contains residues of asphalt particles and salt-laden water 11. These are fed as stream for further purification to the separator D whose separation effect is likewise based on density differences (preferably the separator is designed as a hydrocyclone). , The light oil antisolvent phase 100 "deposited there is fed to the anti-solvent recovery, while the heavy components 12 are fed as stream again to a phase separator F. Alternatively, the separation of the three-phase mixture 10

(solid asphalt particles, oil with antisolvent and water) also occurs sequentially. The three existing phases are not separated simultaneously in a single three-phase separator but in succession. Thus, first the light oil antisolvent phase can be separated in a separator before the remaining asphaltene particles are separated from the water phase by solid-liquid separation, or else a different order is selected for the separation of the three-phase mixture 10.

Which of the alternatives for separating the three-phase mixture 10 leads to better separation results depends significantly on the separation behavior of the phases. A three-phase separator is simple in terms of apparatus, but can only be used if the separation behavior is favorable, so that the three-phase mixture 10 separates well from one another and the phases can be discharged separately.

Whether the separation of the three-phase mixture 10 takes place in a three-phase separator or sequentially in a plurality of separators, a de-emulsifier can be added to the mixing unit A or the container B to improve the phase separations carried out in the subsequent stages. As long as the Phases are thoroughly mixed by the mixing unit A and within the container B, the phases do not separate macroscopically yet. They remain in the emulsified state, which enables an intensive substance exchange over the large phase interface. As soon as mixing energy is no longer introduced and instead there are conditions which favor phase separation (in the separators C, D, E and in the phase separator F), the action of the emulsifier prevails, whereby the phases separate out.

The asphalt particles 400 recovered in the solid-liquid separation and the waste water 300 are end products of the process, while the oil antisolvent streams 100 'and 100 "are fed to the antisolvent recovery, in which the antisolvent is recovered Mixing with the C4-C6

Leichtsiederm again deasphalting to be supplied.

Figure 5 describes a further advantageous embodiment of the invention, in which the described method can be carried out in a simplified apparatus form, when the deasphalting and the water washing done instantaneously, so do not require any significant residence time. In this case, the residence time container B is dispensed with. The mixing unit A continues to produce three-phase mixture (4M from the oil, water and antisolvent streams (1, 2, 3).) The three-phase mixture (4) is fed directly to a phase separator F, where the phases This can advantageously be accelerated by the addition of a de-emulsifier As described above, after deasphalting and desalting, the three phases oil / antisolvent, aqueous salt solution and asphalt particles, which are already present in the embodiments of the invention according to FIGS. Among other things, the backflow 5 required to prevent fouling is provided to the mixing unit A, as well as the further purification of the oil antisolvent phase in separator D and the residual wet asphalt particles in the solid-liquid Separation stage G. The asphalt particles 400 and the effluent 300 are the final products of the process while the oil antisolvent stream 100 "is fed to the anti-solvent recovery 16. As already described in connection with the embodiments of Fig. 4, the separation of the three-phase mixture 4, it is also possible to separate the light oil antisolvent phase in a separator before the remaining asphalt particles are separated from the water phase by solid-liquid separation , or a different order is chosen for the separation of the three-phase mixture.

In all embodiments of the invention, it is possible to add one or more additives before the deasphalting, which bring about an improvement in the properties of the asphalt particles formed in the deasphalting and thus positively influence the subsequent separation of the asphalt particles. These additives may be added before the mixing unit A, in the mixing unit A, in the tank B or in the circuit between the mixing unit A and the tank B. Depending on the properties of the additives and the preferred addition point, they can be admixed with the crude oil 1, the water 2, the anti-solvent 3 or mixtures formed in the process.

Examples include phosphoric acid and phosphorous acid. It is known that both additives, which are water-soluble and thus can preferably be mixed into the water stream 2, influence the properties of the asphalt particles formed.

Claims

claims

1. Process (H) for the substantial removal of alkali, alkaline earth and heavy metals from crude or heavy oil (1), wherein

the raw or heavy oil (1) a largely or completely metal-free water (2) and an antisolvent (3) are added, and the resulting mixture in one

Mixing unit (A) is mixed together such that a multiphase mixture (4, 4 is formed,

in the multiphase mixture (4, 4, the water-soluble alkali and alkaline earth metals from the raw or

Dissolve heavy oil (1) in the form of its salts in the phase of the metal-free water (2), and water-insoluble heavy metals from the crude or heavy oil (1)

Deasphalting with the antisolvent (3) in the form of suspended asphalt particles,

the multiphase mixture (4, 4M by phase separation in a workup stage (F) in purified crude or heavy oil (100), which is desalted and largely of alkali metal,

Alkaline earth metals and heavy metals, is separated into alkaline and alkaline earth metal-rich water (300), and into heavy metal-rich, suspended asphalt particles (400),

characterized in that

the suspended asphalt particles recovered in the process are recycled through a return line (5) into the crude or heavy oil (1) at the area where the antisolvent (3) is added.

2. Method (H) according to claim 1, wherein the multiphase mixture (4, 4M, before it is subjected to the phase separation, is kept in intimate phase contact in a residence time until the equilibration by material transport operations in about 95% completed is.

3. Method (H) according to one of claims 1 or 2, in which the multiphase mixture (4, 4M before the phase separation in a NEN the mixing unit (A) downstream container (B) is passed, wherein a partial flow 5 of the multiphase mixture (4, 4 with suspended asphalt particles from the container (B) in the mixing unit (A) is fed back.

4. Process (H) according to any one of claims 1 to 3, wherein the phase separation takes place in the work-up stage (F), wherein the phase with the oil-antisolvent (11) with residues of asphalt particles and salt-laden water a separator (D) in which the light oil antisolvent

Phase (100 ") of heavy components (12) is separated from the oil antisolvent phase, and

the phase of suspended asphalt particles (15) is fed to a solid-liquid separation stage (G), in which the asphaltene particles (400) are separated from their mother liquor (14).

5. The method (H) according to any one of claims 1 to 4, wherein the mixing unit (A) a water wash device (T2) and a phase separator (T3) are connected upstream, wherein the raw or heavy oil (1) and the substantially or completely metal-free water (2) are supplied to the water washing device (T2) and mixed together to form an emulsion (I) which is supplied to the phase separator (T3) in which a salt-laden water phase (300) is separated, and a remaining phase desalted oil (1 "), together with the antisolvent (3) to the mixing unit (A).

6. The method (H) according to claim 5, wherein the raw or

Heavy oil (1) is supplied to a concentration stage (Tl) before being fed into the water scrubber (T2), in which it is concentrated by evaporation and / or distillation, wherein the volatile components (200) are separated.

7. Method (H) according to one of claims 1 to 6, wherein one or more additives are added to the antisolvent (3). those who improve the separation of the

Deasphalting formed asphalt particles, wherein the additives before the mixing unit (A), and / or in the mixing unit (A), and / or in the circuit between mixing unit (A) and phase separator (F) are added.

8. The method (H) according to any one of claims 3 to 6, wherein the antisolvent (3) one or more additives are added, which improves the separation of the in the

Deasphalting formed asphalt particles, wherein the additives in the container (B), and / or in the circuit between mixing unit (A) and container (B) are added.

9. Method (H) according to claim 7 or 8, in which phosphoric acid and / or phosphorous acid is added as additive.

10. The method (H) according to any one of claims 1 to 9, wherein the ratio between the crude or heavy oil (1) and the water (2) between 5: 1 and 50: 1, preferably 10: 1.

Process (H) according to any one of claims 5 to 10, wherein a de-emulsifier is added to improve the phase separation of the emulsion in the phase separator (T3).

12. The method (H) according to any one of claims 1 to 11, wherein from the crude oil (1) at least a first and a second product stream are separated, wherein

the first product stream is so rich in heavy metals that it has concentrations of vanadium and / or nickel of less than or equal to 0.5 ppm, and can be fed to a high-performance gas turbine for combustion, and

the second product stream is only slightly depleted of heavy metals, that it has a concentration of vanadium and / or nickel of more than 0.5 ppm, and can be fed to a standard gas turbine for combustion.

13. cleaning device (H) for the substantial removal of alkali, alkaline earth and heavy metals from raw and

Heavy oils (1) comprising a mixing unit (A) and a working stage (F), wherein

the raw or heavy oil (1), a largely or completely metal-free water (2) and an antisolvent (3) can be supplied, and in the mixing unit (A) in such a way to a multi-phase mixture (4, 4 are miscible in that multiphase mixture (4, 4 solve the water-soluble alkali and alkaline earth metals from the crude or heavy oil (1) in the form of their salts in the phase of the metal-free water (2), and water-insoluble heavy metals from the crude or heavy oil (1) by deasphalty - tion with the antisolvent (3) in the form of suspended

Asphalt particles fail,

a work-up stage (F) in which the phases of the multiphase mixture (4, 4M are separable, so that a purified crude or heavy oil (100), which is desalted and substantially free of alkali, alkaline earth and heavy metals, an alkali and alkaline-earth-rich water (300), and heavy-metal-rich asphalt particles (400) are separable,

characterized in that

by a return line (5) in the cleaning device (H) recovered, suspended asphalt particles in the crude or heavy oil (1), in the area where the anti-insulating (3) can be fed, is traceable.

14. Cleaning device (H) according to claim 13,

characterized in that

the multiphase mixture (4) is in intimate phase contact for a period of time prior to the work-up step (F) until the equilibration by mass transfer operations is approximately 95% complete.

15. Cleaning device (H) according to claim 13 or 14, characterized in that between the processing step (F) and mixing unit (A), a container (B) is provided, wherein the container (B) with the mixing unit (A) through the return line (5) is connected, so that a partial stream of the multiphase mixture (4, 4 with suspended asphalt particles from the container (B) in the

Mixing unit (A) is traceable.

16. Cleaning device (H) according to one of claims 13 to 15, wherein the work-up stage (F), a separator (D) and a solid-liquid separation stage (G) are connected downstream, wherein

the phase with the oil antisolvent (11) with residues of asphalt particles and salt-laden water can be fed to the separator (D), in which the light oil antisolvent phase (100 ") of heavy components (12) from the light oil -Antisolvent phase can be separated, and the phase of suspended asphalt particles (15) of the solid-liquid separation stage (G) can be fed in the asphalt particles (400) are separated from their mother liquor (14).

17. Cleaning device (H) according to claim 13 to 16, characterized in that

the mixing unit (A) is preceded by a water wash device (T2) and a phase separator (T3), wherein the crude or heavy oil (1) and the largely or completely metal-free water (2) can be fed to the water wash device (T2) and mixed with one another in such a manner, in that an emulsion (I which can be fed to the phase separator (T3) and in which a phase can be separated off with salt-laden water (300) and a residual phase of desalted oil (1 ") together with in the anti-solvent event (3) the mixing unit (A) can be fed.

18. Cleaning device according to claim 17,

characterized in that

the water washing device (T2) is preceded by a concentration stage (Tl), the raw or heavy oil (1) can be supplied, so that the volatile components (200) are separated by evaporation and / or distillation and thus the crude or heavy oil can be concentrated.

19. Cleaning device according to one of claims 13 to 18,

characterized in that

the mixing unit (A), and / or in the mixing unit (A), and / or in the circuit between mixing unit (A) and phase separator (F) one or more additives are introduced, which improve the separation of the formed during the deasphalting Asphalt particles cause.

20. Cleaning device according to one of claims 15 to 18,

characterized in that

the container (B), and / or in the circuit between the mixing unit (A) and container (B) one or more additives are introduced, which improves the separation of the in

Deasphalting formed asphalt particles cause.

21. Cleaning device according to one of claims 15 or 16,

characterized in that

as an additive phosphoric acid and / or phosphorous acid is added.

22. Cleaning device according to one of claims 13 to 21,

characterized in that

the ratio between the crude or heavy oil (1) and the water (2) is between 5: 1 and 50: 1, preferably 10: 1.

23. Cleaning device according to one of claims 17 to 22, characterized in that to improve in the

Phase separator (T3) carried out phase separation of the emulsion is a Deemulgator zusetzbar.

24. Cleaning device according to one of claims 13 to 23,

characterized in that

the crude oil (1) at least in a first and in a second

Product flow is separable, wherein

the first product stream is very heavily depleted in heavy metals so that it has vanadium and / or nickel concentrations of less than or equal to 0.5 ppm, and is combustible in a high-performance gas turbine, and the second product stream is only slightly soluble in heavy metals. is enriched, and has a concentration of vanadium and / or nickel of more than 0.5 ppm, and is combustible in a standard gas turbine.