JP2018002899A - Recover method of oil content in crude oil sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recovery method of an oil component in a crude oil sludge capable of increasing a treatment amount in recovery of the oil component form the crude oil sludge.SOLUTION: There is provided a recovery method of an oil component in a crude oil sludge having a second process for supplying a heating stirring treated article of the crude oil sludge (A) and a crude oil (B) to a decanter type centrifugal separator at 40 to 200°C, separating the same to a first layer consisting of a recovered oil component, a second layer consisting of heavy hydrocarbon, a water layer and a solid article in a separation zone of the decanter type centrifugal separation by centrifugal separation, extracting the first layer from a light side of one edge side of the separation zone to outside of the separation zone to recovery the recovered oil component and extracting the water layer from a heavy side of one edge of the separation zone to outside of the separation zone to recover a moisture content and the heavy hydrocarbon and the solid article are made to a mixture of the heavy hydrocarbon and the solid article in a solid shape at another edge of the separation zone, then discharging the same to outside of the separation zone and recovering the mixture of the heavy hydrocarbon and the solid article.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for recovering oil from crude oil sludge accumulated in a crude oil tank in which crude oil is stored.

  After the crude oil sludge accumulated in the crude oil tank is taken out from the crude oil tank, it is generally treated as industrial waste, but its disposal requires high costs. On the other hand, since crude oil sludge often contains about 30 to 80% by volume of oil, there is a great need for recovery of oil in crude oil sludge.

  Thus, conventionally, attempts have been made to recover oil from crude oil sludge by vacuum distillation, heating separation, centrifugation, or the like (for example, Patent Documents 1 to 3).

International Publication No. 2012/141024 JP-A-3-226482 JP 2004-243300 A

  However, the above-mentioned methods, for example, the vacuum distillation method and the heat separation method, require a large amount of investment in collecting equipment. In addition, there is a problem that a multi-stage separation step is required when a substance separated into four layers by centrifugation is centrifuged.

  Accordingly, an object of the present invention is to provide a method for recovering oil content in crude oil sludge that can recover the oil content in crude oil sludge with simple equipment and fewer steps in recovering the oil content from crude oil sludge.

The above problems are solved by the present invention described below.
That is, according to the present invention, the ratio of the crude oil sludge (A) and the crude oil (B) is 10 to 95% by mass with respect to the total of the crude oil sludge (A) and the crude oil (B). Then, the mixture of crude oil sludge (A) and crude oil (B) is heated and stirred at 40 to 200 ° C. to obtain a heated and stirred processed product of crude oil sludge (A) and crude oil (B). When,
The heated and stirred product is supplied to a decanter type centrifuge at 40 to 200 ° C., and centrifuged, whereby a first layer composed of recovered oil and a heavy oil are separated in the separation region of the decanter type centrifuge. (I) From the light side at one end side of the separation region, while separating the second layer made of hydrocarbons, the water layer, and the solid, and supplying the heated and stirred product to the separation region, Discharging the first layer out of the separation region to recover the recovered oil; and (ii) discharging the aqueous layer out of the separation region from the heavy side at one end of the separation region. And (iii) forming a mixture of solid heavy hydrocarbons and solids with the heavy hydrocarbons and solids at the other end of the separation region, The solid heavy hydrocarbon and solids mixture is discharged out of the separation zone to mix the heavy hydrocarbons and solids A second step of recovering,
The present invention provides a method for recovering an oil content in crude oil sludge.

  ADVANTAGE OF THE INVENTION According to this invention, in the collection | recovery of the oil component from crude oil sludge, the recovery method of the oil component in the crude oil sludge which can collect | recover the oil component in a crude oil sludge can be provided with simple equipment and few processes.

It is typical sectional drawing of the example of a form of the decanter type centrifuge used in order to perform a 2nd process. It is a figure which shows the outer cylinder fixing member 25 in FIG. It is a schematic diagram which shows the isolation | separation state after centrifuging the heating stirring processed material 29 using a batch-type centrifuge. FIG. 4 is a schematic diagram showing a state where layers are separated in a separation region 6. It is a figure which shows the range of the isolation | separation area | region 6 in FIG.

In the method for recovering oil in the crude oil sludge according to the present invention, the ratio of the crude oil sludge (A) to the crude oil (B) is obtained by combining the crude oil sludge (A) and the crude oil (B). The mixture of crude oil sludge (A) and crude oil (B) is heated and stirred at 40 to 200 ° C., and the crude oil sludge (A) and crude oil (B) are heated and stirred. A first step of obtaining a processed product;
The heated and stirred product is supplied to a decanter type centrifuge at 40 to 200 ° C., and centrifuged, whereby a first layer composed of recovered oil and a heavy oil are separated in the separation region of the decanter type centrifuge. (I) From the light side at one end side of the separation region, while separating the second layer made of hydrocarbons, the water layer, and the solid, and supplying the heated and stirred product to the separation region, Discharging the first layer out of the separation region to recover the recovered oil; and (ii) discharging the aqueous layer out of the separation region from the heavy side at one end of the separation region. And (iii) forming a mixture of solid heavy hydrocarbons and solids with the heavy hydrocarbons and solids at the other end of the separation region, The solid heavy hydrocarbon and solids mixture is discharged out of the separation zone to mix the heavy hydrocarbons and solids A second step of recovering,
It is the recovery method of the oil content in the crude oil sludge characterized by having.

  In the first step of the method for recovering oil in crude oil sludge of the present invention, crude oil sludge (A) and crude oil (B) are mixed, and then a mixture of crude oil sludge (A) and crude oil (B) This is a step of heating and stirring at ˜200 ° C. to obtain a heated and stirred processed product of crude oil sludge (A) and crude oil (B).

  Crude oil sludge (A) according to the first step is sludge generated from the crude oil in which the crude oil is stored and deposited on the bottom of the crude oil tank. Crude oil sludge (A) is removed from solids, moisture, etc. after crude oil extraction, stored in a crude oil tank, generated from crude oil in the crude oil tank before being shipped to a refinery, and deposited at the bottom of the crude oil tank Crude oil sludge; crude oil sludge accumulated at the bottom of a crude oil tank of a crude oil tanker; crude oil sludge generated from crude oil in a crude oil tank for storage before being refined at a refinery, and deposited at the bottom of the crude oil tank. Crude oil sludge (A) may be generated from one type of crude oil or may be generated from a plurality of types of crude oil.

  Crude oil sludge (A) contains oil, asphaltene, iron, sand, water and the like. The oil in the crude oil sludge (A) is mainly paraffins and aromatic hydrocarbons having 40 or more carbon atoms. And the oil content in this crude oil sludge (A) is a component collect | recovered from crude oil sludge (A) by the recovery method of the oil content in the crude oil sludge of this invention.

  The method of taking out the crude oil sludge (A) deposited in the crude oil tank is not particularly limited. For example, the crude oil deposited in the crude oil tank after the crude oil in the crude oil tank is extracted out of the crude oil tank. A method of injecting high-pressure crude oil into sludge (A) and pushing crushed or partially dissolved crude oil sludge (A) out of the crude oil tank with crude oil (COW: Crude Oil Washing). Crude oil in the crude oil tank is taken out of the crude oil tank. Examples include a method of manually extracting the crude oil sludge (A) accumulated in the crude oil tank after the extraction.

  The crude oil (B) to be mixed with the crude oil sludge (A) is not particularly limited, and may be a crude oil before removing solids or moisture after the crude oil is mined and stored in the crude oil tank. The crude oil that has just been stored in the crude oil tank after removing water and moisture, etc., may be crude oil before the crude oil sludge is generated, or the crude oil sludge at the bottom of the crude oil tank by storing it in the crude oil tank for a certain period of time. It may be the crude oil in the crude oil tank after the occurrence of. Crude oil (B) may be the same type of crude oil as the source of crude sludge (A) or a different type of crude oil.

  When removing crude oil sludge (A) from the crude oil tank, if the crude oil sludge (A) is taken out by pushing the crude oil sludge (A) out of the crude oil tank with crude oil (for example, COW), it is removed from the crude oil tank. This is a mixture of crude oil sludge (A) and crude oil used to remove crude oil sludge (A). In this case, the crude oil used to remove crude oil sludge (A) is crude oil (B). include.

  In the first step, first, the ratio of crude oil sludge (A) to the total of crude oil sludge (A) and crude oil (B) is 20 to 95 mass%, preferably 40 to 90 mass%, more preferably 60 to 90 mass%. Crude oil sludge (A) and crude oil (B) are mixed so that it may become the mass%. If the ratio of crude oil sludge (A) to the total of crude oil sludge (A) and crude oil (B) is less than the above range, the processing amount in the second step will increase, resulting in a decrease in economic efficiency, If it exceeds, recovery of oil from the crude oil sludge (A) will be insufficient.

  When the crude oil sludge (A) is taken out from the crude oil tank, when the crude oil sludge (A) is taken out by pushing the crude oil sludge (A) out of the crude oil tank with crude oil (for example, COW washing), the crude oil sludge ( The crude oil used for taking out A) is included in crude oil (B), and the ratio of crude oil sludge (A) to the total of crude oil sludge (A) and crude oil (B) is calculated. Therefore, in this case, the ratio of the crude oil sludge (A) accumulated in the bottom of the crude oil tank and the crude oil sludge (A) to the total crude oil used to take out the crude oil sludge (A) is a predetermined mixing ratio, that is, the crude oil Use crude oil in such an amount that the ratio of crude sludge (A) to the sum of sludge (A) and crude oil (B) is 20 to 95 mass%, preferably 40 to 90 mass%, more preferably 60 to 90 mass%. Then, the crude oil sludge (A) is taken out of the crude oil tank, and the extracted crude oil sludge (A) and crude oil mixture may be used as a mixture of crude oil sludge (A) and crude oil (B) used for heating and stirring as they are. Alternatively, the crude oil sludge (A) accumulated at the bottom of the crude oil tank is taken out of the crude oil tank using a small amount of crude oil, and the mixture of the extracted crude oil sludge (A) and the crude oil is further mixed with the crude oil sludge (A). ) The same or different types of crude oil used for the extraction of crude oil are mixed, and the predetermined mixing ratio, that is, the ratio of crude oil sludge (A) to the total of crude oil sludge (A) and crude oil (B) is 10 to 95% by mass, preferably 40 to 90% by mass, more preferably 60 to 90% by mass, and the resulting mixture may be a mixture of crude oil sludge (A) and crude oil (B) used for heating and stirring. .

  In the first step, the mixture of crude oil sludge (A) and crude oil (B) is then heated and stirred at 40 to 200 ° C., preferably 50 to 150 ° C., more preferably 60 to 100 ° C. to obtain crude oil sludge (A). And a heated and stirred product of crude oil (B). When the heating and stirring temperature is less than the above range, oil recovery from the crude oil sludge (A) becomes insufficient, and when it exceeds the above range, disadvantages due to loss of light fractions occur. The method of heating and stirring the mixture of crude oil sludge (A) and crude oil (B) is not particularly limited. For example, in a tank in which crude oil sludge (A) taken out from the crude oil tank is stored, crude oil sludge ( The method of heating and stirring the mixture of A) and crude oil (B) is mentioned. The heating and stirring time is not particularly limited and is selected according to the stirring conditions so as to obtain a uniform mixed state.

  Although content in particular of oil content in crude oil sludge (A) is not restrict | limited, Usually, it is 30-80 mass%. And the oil content in this crude oil sludge (A) is a mixture of crude oil sludge (A) and crude oil (B) in a 1st process, 40-200 degreeC, Preferably it is 50-150 degreeC, More preferably, it is 60-100 degreeC Dissolve in crude oil (B) by stirring with heating.

  In the second step according to the method for recovering the oil content in the crude oil sludge of the present invention, the heated and stirred crude oil sludge (A) and crude oil (B) obtained in the first step are decanted at 40 to 200 ° C. By supplying to the centrifugal separator and centrifuging, in the separation region of the decanter centrifugal separator, the first layer made of recovered oil, the second layer made of heavy hydrocarbons, the water layer, and the solid matter (I) discharging the first layer out of the separation region from the light side on one end side of the separation region and supplying the recovered oil And (iii) draining the water layer out of the separation region from the heavy side at one end of the separation region to collect moisture, and (iii) at the other end side of the separation region, After forming a mixture of solid heavy hydrocarbons and solids with heavy hydrocarbons and solids, The mixture of heavy hydrocarbons and solids, is discharged to the outside of the isolation region, a step of recovering the mixture of heavy hydrocarbons and solid.

  A decanter centrifuge used for performing the second step will be described. The decanter centrifuge used for performing the second step is at least an inner cylinder in which a workpiece supply port for discharging the workpiece from the inside to the outside and supplying it to the separation region is formed, An outer cylinder that is provided outside the inner cylinder so as to surround the inner cylinder, has a solid content discharge port for discharging the solid content from the inner side to the outer side, and forms a separation region with the inner cylinder And a screw plate spirally wound on the outer wall of the inner cylinder, provided on one end side of the separation area (the side where the first layer and the water layer are discharged from the separation area), and lighter toward the inner cylinder And a partition wall in which a heavy discharge path is formed near the outer cylinder.

  A decanter centrifuge used for performing the second step will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an example of a decanter centrifuge used for performing the second step. In FIG. 1, a decanter centrifuge 1 includes an inner cylinder 2, an outer cylinder 3, an inner cylinder rotating shaft 23, an outer cylinder rotating shaft 24, a gear box 13, a screw plate 7, a partition wall. 10 and an outer cylinder fixing member 25.

  The inner cylinder 2 is a cylindrical member, and is attached so as to be rotatable about a rotation axis. A hollow object supply pipe 27 for supplying an object to be processed (heat-stir processed object in the present invention) 29 into the inner cylinder 2 is connected to the object supply side of the inner cylinder 2. Further, the inner cylinder 2 has an inner side for closing the inner cylinder 2 opposite to the workpiece supply side and fixing the inner cylinder 2 to the inner cylinder rotating shaft 23 on the opposite side of the inner cylinder 2 from the workpiece supply side. A tube fixing member 26 is provided. In the inner cylinder 2, a plurality of object supply ports 4 are formed in the circumferential direction of the inner cylinder 2 for discharging the object 29 supplied to the inside from the inside to the outside and supplying it to the separation region 6. ing.

  The outer cylinder 3 is a cylindrical member and is provided outside the inner cylinder 2 so as to surround the inner cylinder 2. The outer cylinder 3 is attached so as to be rotatable about a rotation axis. On the opposite side of the outer cylinder 3 from the workpiece supply side, an outer cylinder is fixed to close the opposite side of the outer cylinder 3 from the workpiece supply side and fix the outer cylinder 3 to the outer cylinder rotating shaft 24. A member 25 is provided. The outer cylinder 3 is formed with a solid content discharge port 5 for discharging the solid content.

  Then, by disposing the inner cylinder 2 inside the outer cylinder 3, a separation region 6 is formed between the inner cylinder 2 and the outer cylinder 3.

  A screw plate 7 that is spirally wound is provided on the outer wall of the inner cylinder 2. The screw plate 7 rotates the inner cylinder 2 relative to the outer cylinder 3 so that the solid material existing between the inner cylinder 2 and the outer cylinder 3 is transferred to the solid content outlet 5 of the outer cylinder. It is a member for conveying. Therefore, the screw plate 7 rotates so that the inner cylinder 2 rotates relative to the outer cylinder 3, so that the solid content between the inner cylinder 2 and the outer cylinder 3 is changed to the solid content discharge port 5 of the outer cylinder. It has a spiral shape that can be transported to

  The partition wall 10 is a member for partitioning the light and heavy discharge sides of the separation region 6 formed between the inner cylinder 2 and the outer cylinder 3. In the partition wall 10, a light discharge path 38 and a heavy discharge path 37 are formed. The partition wall 10 is installed in the circumferential direction of the inner cylinder 2 and the outer cylinder 3. In the embodiment shown in FIG. 1, the partition wall 10 is formed integrally with the outer cylinder fixing member 25.

  With reference to FIG. 2, the discharge path 38 for light and the discharge path 37 for heavy will be described. 2 is a view showing the outer cylinder fixing member 25 in FIG. 1. FIG. 2 (a) is a view of the outer cylinder fixing member 25 in FIG. 1 as viewed from the separation region 6 side. It is an AA 'line sectional view of (a). In the outer cylinder fixing member 25, a portion facing the space between the outer cylinder and the inner cylinder is the partition wall 10. In the embodiment shown in FIG. 2, the partition wall 10 is formed integrally with the outer cylinder fixing member 25. A light component discharge port 381 is formed concentrically on the surface of the outer tube fixing member 25 on the partition wall 10 side, and the light connection port 381 is connected to the light component discharge space 142 inside the outer tube fixing member 25. A passage 382 is formed. The light component discharge port 381 and the communication passage 382 become the light component discharge path 38. In addition, a heavy component discharge port 371 is formed concentrically outside the light component discharge port 381 on the surface of the outer tube fixing member 25 on the partition wall 10 side, and the heavy component discharge port is formed inside the outer tube fixing member 25. A communication passage 372 connecting the 371 and the heavy discharge space 141 is formed. The heavy component discharge port 371 and the communication passage 372 serve as a heavy component discharge path 37.

  The outer cylinder 3 is connected to a driving device (not shown), the workpiece supply side is supported by the bearing 21, and the opposite side to the workpiece supply side is fixed via the outer cylinder fixing member 25. The rotary shaft 24 is supported by the bearing 22 so that it can be rotated. Further, the inner cylinder 2 is rotatably mounted by being supported by the bearing 18 on the workpiece supply side and supported by the bearing 19 on the side opposite to the workpiece supply side.

  The outer cylinder rotating shaft 24 is hollow, one end side is connected to the gear box 13, and the outer cylinder fixing member 25 is fixed to the other end side. Further, the inner cylinder rotating shaft 23 is disposed inside the outer cylinder rotating shaft 24, one end side is connected to the gear box 13, and the inner cylinder fixing member 26 is fixed to the other end side. Then, the gear box 13 causes a rotational speed difference from the outer cylinder 3 to the inner cylinder 2 to transmit power. Therefore, when the outer cylinder 3 is rotated by the driving device, the inner cylinder 2 rotates at a slightly lower rotational speed than the outer cylinder 3.

  A casing 20 is provided so as to surround the outer side of the outer cylinder 3. A solid content discharge space 16 for discharging the solid content from the outer cylinder 3 is provided on the workpiece supply side in the housing 20, and the solid content is discharged out of the decanter centrifuge 1. For this purpose, a solid content outlet 17 is formed. On the side opposite to the workpiece supply side in the housing 20, a light component discharge space 142 for discharging light components from the outer tube 3 and a heavy component discharge space for discharging heavy components from the outer tube 3. 141 is provided. In the housing 20, the light component discharge space 142 and the heavy component discharge space 141 are partitioned so that the light component and the heavy component are not mixed. Further, a light component discharge port 152 for discharging the light component out of the decanter centrifuge 1 and a light component discharge port 151 for discharging the heavy component out of the decanter centrifuge 1 are formed. Yes.

  Next, the 2nd process performed using the decanter-type centrifuge 1 shown in FIG. 1 is demonstrated. Crude oil sludge (A) and crude oil (A) and crude oil (A) and crude oil (A) and crude oil (A) having a predetermined processing temperature in a state where the temperature in the decanter centrifuge 1 is maintained at a predetermined processing temperature and the inner cylinder 2 and the outer cylinder 3 are rotated at a predetermined rotation speed. The heated and stirred processed material 29 of B) is supplied to the inside of the inner cylinder 2 from the processing object supply pipe 27. The heated and stirred processed product 29 supplied into the inner cylinder 2 passes through the workpiece supply port 4 and is supplied to the separation region 6 formed between the inner cylinder 2 and the outer cylinder 3.

  The heated and stirred processed product 29 supplied to the separation region 6 is centrifuged in the separation region 6. Here, the centrifugation in the second step will be described with reference to FIGS. FIG. 3 is a schematic view showing a separated state after the heated and stirred processed product 29 of crude oil sludge (A) and crude oil (B) is centrifuged at a predetermined processing temperature using a batch-type centrifuge. . FIG. 4 is a schematic diagram showing a state in which each layer is separated in the separation region 6. FIG. 5 is a diagram showing the range of the separation region 6 in FIG. As shown in FIG. 3, in the centrifuge tube 30, the heated and stirred processed material 29 is, by centrifugation, in order from the top, a first layer 34 made of recovered oil 31 and a second layer made of heavy hydrocarbon 32. 35, an aqueous layer 36, and a solid material 28. Therefore, as shown in FIG. 4, in the separation region 6 (the portion shown by hatching in FIG. 5), from the inner cylinder 2 side, in other words, from the one having a smaller specific gravity, the first layer 34, the second layer 35, and The water layer 36 is separated into three layers, and the solid matter 28 settles on the outer cylinder 3 side in the vicinity of the formation position of the workpiece supply port in the water layer 36.

  In the second step, the first layer 34, the second layer 35, the water layer 36, and the solid material 28 are separated in the separation region 6 by centrifugal separation. The first layer 34 is discharged out of the separation area 6 from the light discharge path 38 formed in the partition wall 10 and the outer cylinder fixing member 25 while supplying the heated and stirred processed material 29 to the area 6. In addition, the water layer 36 is discharged out of the separation region 6 from the heavy discharge path 37 formed in the partition wall 10 and the outer cylinder fixing member 25, and the heavy layer constituting the second layer 35 is formed. The hydrocarbon 32 and the solid 28 form a solid heavy hydrocarbon and solid mixture 40, and the solid heavy hydrocarbon and solid mixture 40 is discharged out of the separation region 6. To do.

  At this time, since the heated and stirred product 29 is continuously supplied into the separation region 6, the recovered oil component is continuously separated by centrifugation in the separation region 6, so that the first layer 34 is correspondingly separated. And the increased amount of recovered oil 31 is discharged out of the separation region 6 from the light discharge path 38.

  In addition, since the heated and stirred processed material 29 is continuously supplied into the separation region 6, the water is continuously separated by centrifugation in the separation region 6, so that the water layer 36 increases by that amount. Thus, the increased amount of water 33 is discharged out of the separation region 6 from the heavy discharge path 37.

  Further, by continuously supplying the heated and stirred processed product 29 into the separation region 6, the solid matter 28 is continuously separated by centrifugation in the separation region 6, and the separated solid matter 28 is separated. It sinks to the outer cylinder 3 side in the water layer 36 in the region 6. In addition, since the heated and stirred processed product 29 is continuously supplied into the separation region 6, heavy hydrocarbons are continuously separated by centrifugation in the separation region 6. Layer 35 increases. Then, the settled solid matter 28 is conveyed to the other end side 39 of the second layer 35 by the screw plate, where it comes into contact with the heavy hydrocarbon 32 and is a mixture of solid heavy hydrocarbon and solid matter. 40 is formed. Further, the heavy hydrocarbon and solid mixture 40 is conveyed to the solid portion discharge port 5 of the outer cylinder by the screw plate, and is discharged out of the separation region 6, and is discharged from the solid portion discharge port 5 of the outer cylinder. 3 is discharged outside.

  That is, in the second step, (i) the first layer 34 is discharged out of the separation region 6 from the light side on one end side of the separation region 6, the recovered oil 31 is recovered, and (ii) the separation region 6, the water layer 36 is discharged out of the separation region 6 from the heavy side at one end side, and the moisture 33 is recovered. (Iii) On the other end side of the separation region 6, the heavy hydrocarbon 32 and After the solid 28 forms a solid heavy hydrocarbon and solid mixture 40, the heavy hydrocarbon and solid mixture 40 is discharged out of the separation region 6 to form a solid heavy. A mixture 40 of solid hydrocarbons and solids is recovered.

  In this manner, the second step is performed using the decanter type centrifuge 1 to recover the recovered oil, moisture, and the mixture of solid heavy hydrocarbon and solid matter.

  In the second step, the temperature when the heat-stirred processed product of crude oil sludge (A) and crude oil (B) is centrifuged is 40 to 200 ° C, preferably 50 to 150 ° C, more preferably 60 to 100 ° C. is there. If the centrifugation temperature is less than the above range, some of the heat-stirred products of crude oil sludge (A) and crude oil (B) will solidify during centrifugation, or the fluidity of the heat-stirred products will greatly decrease. Therefore, the centrifugal separation cannot be performed, and if it exceeds the above range, a demerit due to loss of the light fraction occurs. Further, in the second step, the temperature at which the crude oil sludge (A) and the crude oil (B) are heated and stirred is centrifuged at the temperature of the mixture of the crude oil sludge (A) and the crude oil (B) in the first step. It is about the same as the heating and stirring temperature.

  The heated and stirred processed product of crude oil sludge (A) and crude oil (B) obtained by performing the first step is a mixture of recovered oil, heavy hydrocarbons, moisture and solids. In the second step, In the separation region of the decanter type centrifuge, the first layer made of recovered oil, the second layer made of heavy hydrocarbons, the water layer, and the solid matter are separated by the specific gravity difference. The recovered oil that forms the first layer is a liquid obtained by dissolving the oil in the crude oil sludge (A) in the crude oil (B) in the first step. That is, the recovered oil basically consists of crude oil (B) and oil in the crude oil sludge (A) dissolved in the crude oil (B). The heavy hydrocarbon forming the second layer is a component in the crude oil sludge (A) that did not dissolve in the crude oil (B) in the first step, and did not dissolve in the crude oil (B) such as asphaltenes. It is a heavy hydrocarbon. The water that forms the water layer is the water in the crude oil sludge (A). Solids are iron, sand, moat etc. in crude oil sludge (A).

  In the second step, the centrifugal separator for centrifuging the heated and stirred processed product has at least a processed product supply port for discharging the processed product from the inside to the outside and supplying the processed product to the separation region. The inner cylinder is provided outside the inner cylinder so as to surround the inner cylinder, and a solid content discharge port for discharging the solid content from the inside to the outside is formed, and a separation region is formed between the inner cylinder and the inner cylinder. For the outer cylinder, a screw plate spirally wound on the outer wall of the inner cylinder, and one end side of the separation region, and a light discharge path is formed closer to the inner cylinder and closer to the outer cylinder. A decanter centrifuge having a partition wall in which a discharge path for heavy components is formed.

  The inner cylinder is a cylindrical member, and is attached so as to be rotatable about a rotation axis. A hollow object supply pipe for supplying a heated and stirred process object, which is an object to be processed, into the inner cylinder is connected to the object supply side of the inner cylinder. The inner cylinder is formed with a workpiece supply port for discharging the workpiece supplied to the inside from the inside to the outside and feeding it to a separation region formed between the inner cylinder and the outer cylinder. . The position, number, and size of the workpiece supply port formed in the inner cylinder are appropriately selected. Further, both ends of the inner cylinder are closed by appropriate means, and one end side of each of the inner cylinders is fixed to an inner cylinder rotating shaft connected to a member that causes a rotational speed difference from the outer cylinder.

  The outer cylinder is a cylindrical member, and is provided outside the inner cylinder so as to surround the inner cylinder. The outer cylinder is attached to be rotatable about the same rotation axis as the inner cylinder. A solid content discharge port for discharging the solid content is formed on one end side of the outer cylinder. The position, number, and size of the solid content outlet formed in the outer cylinder are appropriately selected. Further, the end of the outer cylinder on the side where the solid content outlet is formed is closed by an appropriate means. In addition, a partition wall is formed at the end of the outer cylinder opposite to the side on which the solid content outlet is formed, and the outer side is connected to a member that causes a difference in rotational speed from the inner cylinder. It is fixed to the rotating shaft for the outer cylinder. The outer cylinder is rotationally driven by a driving device.

  And an isolation | separation area | region is formed between an inner cylinder and an outer cylinder by arrange | positioning an inner cylinder inside an outer cylinder.

  A screw plate wound in a spiral shape is provided on the outer wall of the inner cylinder. A screw board is a member for conveying the solid thing which exists between an inner cylinder and an outer cylinder to a solid content discharge port, when an inner cylinder rotates relatively with respect to an outer cylinder. Therefore, the screw plate conveys the solid object existing between the inner cylinder and the outer cylinder to the solid content outlet of the outer cylinder by rotating the inner cylinder relative to the outer cylinder. It is only necessary to have a spiral shape so that

  The partition wall is a member for partitioning the discharge side of the light component and the heavy component in the separation region formed between the inner tube and the outer tube. In the partition wall, a light discharge path is formed near the inner cylinder, and a heavy discharge path is formed near the outer cylinder. The partition walls are installed in the circumferential direction of the inner cylinder and the outer cylinder. In the second step, the first layer is discharged out of the separation area from the lighter discharge route, and the recovered oil that formed the first layer passes through the lighter discharge route into the lighter discharge space. The water layer is discharged out of the separation region from the heavy discharge route, and the water that formed the water layer passes through the heavy discharge route into the heavy discharge space. Discharged.

  In the second step, the separation region depends on the formation position of the light discharge path 38 of the partition wall 10, the formation position of the heavy discharge path 37, and the formation position of the solid content discharge port 5 of the outer cylinder 3. The discharge of the first layer 34 from 6, the discharge of the aqueous layer 36 from the separation region 6, and the discharge of the heavy hydrocarbon and solid mixture 40 from the separation region 6 are controlled. Therefore, in the second step, the separation of the first layer 34, the second layer 35, the water layer 36 and the solid material 28 in the separation region 6, the discharge of the first layer 34 from the separation region 6, and the separation region 6 The formation position of the light portion 38 and the heavy portion of the partition wall 10 so that the water layer 36 from the separation wall 6 and the heavy hydrocarbon and solid mixture 40 from the separation region 6 are appropriately discharged. The formation position of the discharge path 37 and the formation position of the solid content discharge port 5 of the outer cylinder 3 are adjusted as appropriate.

  For example, in the embodiment shown in FIG. 4, the position closest to the inner cylinder (the position indicated by reference numeral 41 in FIG. 4) of the light discharge path 38 formed in the partition wall 10 and the solid content of the outer cylinder 3. If the position of the reference numeral 43 is closer to the inner cylinder than the position of the reference numeral 41 in relation to the position of the discharge port 5 closest to the first layer (the position indicated by the reference numeral 43 in FIG. 4), the solid Since the first layer 34 is discharged from the object discharge port 5, the position of the reference numeral 41 must be closer to the outer cylinder than the position of the reference numeral 43. Also, if the position closest to the outer cylinder (the position indicated by reference numeral 42 in FIG. 4) of the heavy discharge path formed in the partition wall 10 is too close to the inner cylinder, the heavy discharge path The second layer 34 is discharged from 37.

  The inner cylinder rotating shaft has one end connected to the inner cylinder and the other end connected to a member that causes a difference in rotational speed between the inner cylinder and the outer cylinder. The outer cylinder rotating shaft has one end connected to the outer cylinder and the other end connected to a member that causes a rotational speed difference between the inner cylinder and the outer cylinder. And the power from an outer cylinder produces | generates a rotational speed difference and is transmitted to an inner cylinder through the member which produces a rotational speed difference between an inner cylinder and an outer cylinder. Thus, the inner cylinder and the outer cylinder can be rotated with a slight rotational speed by rotating the outer cylinder with the driving device.

  The outer cylinder is surrounded by an appropriate casing, and light and heavy components discharged from the outer cylinder are respectively formed on the light emission path and heavy discharge path inside the casing. There are provided a light discharge space and a heavy discharge space that are discharged in a separated state, and each of the recovered oil and moisture is decanted from the light discharge space and the heavy discharge space. A light component outlet and a heavy component outlet for discharging out of the mold centrifuge are formed. In addition, on the side where the solid content discharge port is formed in the housing, a discharge space for solids discharged from the outer cylinder is provided, and further, the solid content is discharged from the solid content discharge space of the decanter centrifuge. A solid content outlet is formed for discharge to the outside.

  Then, in the second step, in the separation region of the decanter centrifuge according to the second step, the heated and stirred processed product is divided into a first layer made of recovered oil, a second layer made of heavy hydrocarbons, water The first layer consisting of recovered oil is discharged out of the separation region from the lighter discharge route while supplying the heated and stirred processed material continuously to the separation region. Furthermore, the recovered oil discharged outside the separation area is discharged outside the decanter centrifuge, the recovered oil is recovered, and the aqueous layer is separated from the heavy discharge path. Further, the water discharged out of the separation area is discharged out of the decanter centrifuge, the water is collected, and the solid is transported to the other end of the separation area. A mixture of solid heavy hydrocarbons and solids at the other end of the separation region with heavy hydrocarbons and solids After the formation, the mixture of heavy hydrocarbons and solid matter is discharged out of the separation region, and further transported to the solid content discharge port of the outer cylinder, from the solid content discharge port of the outer cylinder to the outside of the outer cylinder. And the heavy hydrocarbon and solid mixture is discharged out of the decanter centrifuge to recover the solid heavy hydrocarbon and solid mixture.

The physical properties of the recovered oil collected in the second step are not particularly limited, but the density is preferably 0.80 to 0.95 g / cm ³ , more preferably 0.80 to 0.88 g / cm ³ , The melting point is preferably 40 to 150 ° C., more preferably 40 to 110 ° C., still more preferably 40 to 90 ° C., and the freezing point is preferably 30 to 140 ° C., more preferably 30 to 100 ° C., and further preferably 30 to 80 ° C. The oil content is 60% by mass or more.

  Thus, in the method for recovering oil in crude oil sludge of the present invention, oil, heavy hydrocarbons, moisture and solids dissolved in crude oil (B) in crude oil sludge (A) are converted into crude oil (B). In the dissolved state, it can be separated into an oil component dissolved in the crude oil (B), moisture, and a mixture of heavy hydrocarbons and solids, and each can be recovered.

  The oil and the crude oil (B) dissolved in the crude oil (B) in the crude oil sludge (A) have properties that can be used as crude oil. Moreover, in the method for recovering the oil content in the crude oil sludge according to the present invention, the centrifugal separation can be continuously performed using a decanter type centrifugal separation. Therefore, according to the method for recovering the oil content in the crude oil sludge of the present invention, it is possible to recover the effective oil content as the crude oil in the crude oil sludge (A) and increase the throughput of the crude oil sludge (A). .

  Further, since the heavy hydrocarbon in the crude oil sludge (A) is a component that lowers the quality of the crude oil, the component that lowers the quality of the crude oil is selectively removed or reduced by the method for recovering the oil content in the crude oil sludge of the present invention. The oil content effective as crude oil can be recovered from the crude oil sludge (A).

  Moreover, the water | moisture content isolate | separated from crude oil sludge (A) with the recovery method of the oil component in the crude oil sludge of this invention can be suitably processed with a waste water treatment method. In addition, the heavy hydrocarbons and solids, which are unnecessary components in the crude oil sludge (A), can be recovered in solid form together. Therefore, according to the method for recovering the oil content in the crude oil sludge of the present invention, the disposal of the crude oil sludge (A) is facilitated.

  Moreover, since water | moisture content can be isolate | separated from a crude oil sludge (A) in the state which can be processed with the oil component and waste water treatment method effective as a crude oil, what is necessary is just to discard a heavy hydrocarbon and solid as industrial waste. Therefore, according to the method for recovering oil in the crude oil sludge of the present invention, the amount of industrial waste can be reduced.

  Further, after the method for recovering oil in the crude oil sludge according to the present invention is performed, the recovered oil is mixed with the crude oil (C) by mixing the recovered oil with the recovered oil (C) in the crude oil transfer pipe, for example. be able to. The crude oil transfer pipe is a transfer pipe for transferring the crude oil (C), and since the crude oil (C) flows therethrough, mixing the recovered oil with the crude oil (C) in the crude oil transfer pipe means that the crude oil transfer It refers to mixing the recovered oil with crude oil (C) that is flowing in the pipe.

  The crude oil (C) with which the recovered oil is mixed is not particularly limited, and may be crude oil before removing the solid content or moisture after crude oil mining and storing it in the crude oil tank. The crude oil that has just been stored and stored in the crude oil tank may be the crude oil before the crude oil sludge was generated, or the crude oil sludge was generated at the bottom of the crude oil tank by storing it in the crude oil tank for a certain period of time. It may be the crude oil in the crude oil tank later. Crude oil (C) may be the same type of crude oil as the source of crude oil sludge (A) or a different type of crude oil, and may be the same type of crude oil as crude oil (B). Or different types of crude oil.

  Examples of the method for introducing the recovered oil into the crude oil (C) in the crude oil transfer pipe include mixing by line mixing, a static mixer, an injection nozzle, a mixing valve, and the like.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

<Crude oil sludge (A)>
Crude oil sludge recovered from crude oil tank a
Analytical values: oil content 64.3% by weight, asphaltene content 11.4% by weight, moisture 21.0% by weight, sediment content 3.3% by weight
<Crude oil (B)>
Crude oil b with the following analytical value
API 38.1 °, water mud content 0.05% by volume

(Example 1)
Crude oil sludge a and crude oil b were added to a stirring vessel so that the ratio of crude oil sludge a to the total was 50% by mass, and the mixture was heated and stirred at 80 ° C.
Next, while maintaining the temperature at 80 ° C., the heated stirring process product is supplied to the decanter centrifuge 1 shown in FIG. 1 set at 80 ° C., and the heating stirring process is performed at 80 ° C., 3500 G, the rotation speed of the inner cylinder 5 rpm. Centrifugation was performed under the condition of a product supply rate of 0.5 kL / hour to separate and collect the recovered oil, moisture and solid matter. At this time, the recovered oil content was 75.6% by mass, the water content was 10.6% by mass, and the solid product was 13.8% by mass with respect to the total amount of the recovered product. The composition of the recovered oil was 94.1% by mass of oil, 4.9% by mass of asphaltene, 0.2% by mass of moisture, and 0.8% by mass of sediment.
Next, the recovered oil was mixed with the crude oil b so that the ratio of the recovered oil to the total was 5% by mass to obtain a mixed crude oil. When the API and water mud content of the obtained mixed crude oil were measured, the properties were at a level that could be used as crude oil. The recovered water was at a level that could be treated as waste water. Further, in the recovered solid material, the oil content was 48.8% by mass, the asphaltene content was 27.7% by mass, the water content was 14.0% by volume, and the solid material was 9.5% by mass.

(Comparative Example 1)
A two-phase screw decanter was used as the decanter type centrifuge. Crude oil sludge a and crude oil b were added to a stirring vessel so that the ratio of crude oil sludge a to the total was 60 mass%, and the mixture was heated and stirred at 80 ° C.
Next, while maintaining the temperature at 80 ° C., the heated and stirred processed product is supplied to a two-phase decanter centrifuge, and the heating rate of the heated and stirred processed product is 0.4 kL / 80 ° C., 3000 G, the rotation speed of the inner cylinder is 5 rpm. Centrifugation was performed under the conditions of time, and the recovered oil and the viscous material in a state where water and solid matter cannot be separated were recovered. At this time, the recovered oil content was 76.0% by volume and the viscous material was 24.0% by volume with respect to the total amount of the recovered material. The composition of the recovered oil is 79.1% by weight of oil, 5.7% by weight of asphaltene, 13.0% by weight of water, and 2.1% by weight of sediment. It turned out that the thing was mixed. Therefore, even if the recovered oil is mixed with crude oil, there is a concern about the generation of sludge, which is not a level that can be used as crude oil. In the recovered viscous material, the oil content was 79.1% by mass, asphaltene 5.7% by mass, moisture 13.0% by mass, and solids 2.1% by mass.

DESCRIPTION OF SYMBOLS 1 Decanter type centrifuge 2 Inner cylinder 3 Outer cylinder 4 To-be-processed object supply port 5 Outlet solid content discharge port 6 Separation area 7 Screw plate 10 Partition wall 13 Gear box 16 Solid content discharge space 17 Solid content of housing Discharge port 18, 19, 21, 22 Bearing 20 Housing 23 Inner cylinder rotating shaft 24 Outer cylinder rotating shaft 25 Outer cylinder fixing member 26 Inner cylinder fixing member 27 Processed object supply pipe 28 Solid object 29 Processed object (heating) Stir processed product)
30 Centrifugal tube 31 Recovered oil 32 Heavy hydrocarbon 33 Moisture 34 First layer 35 Second layer 36 Water layer 37 Heavy portion discharge path 38 Light portion discharge path 39 Second layer other end side 40 Heavy carbonization Mixture 141 of hydrogen and solid matter Exhaust space 142 for heavy part Exhaust space 151 for light part Heavy part outlet 152 of casing 152 Light part outlet 371 of casing Heavy part outlet 372 Communication path 381 Light part outlet 382 communication passage

Claims (2)

Crude oil sludge (A) and crude oil (B) are mixed so that the ratio of crude oil sludge (A) to the sum of crude oil sludge (A) and crude oil (B) is 10 to 95% by mass, A first step of heating and stirring a mixture of crude oil sludge (A) and crude oil (B) at 40 to 200 ° C. to obtain a heated and stirred processed product of crude oil sludge (A) and crude oil (B);
The heated and stirred product is supplied to a decanter type centrifuge at 40 to 200 ° C., and centrifuged, whereby a first layer composed of recovered oil and a heavy oil are separated in the separation region of the decanter type centrifuge. (I) From the light side at one end side of the separation region, while separating the second layer made of hydrocarbons, the water layer, and the solid, and supplying the heated and stirred product to the separation region, Discharging the first layer out of the separation region to recover the recovered oil; and (ii) discharging the aqueous layer out of the separation region from the heavy side at one end of the separation region. And (iii) forming a mixture of solid heavy hydrocarbons and solids with the heavy hydrocarbons and solids at the other end of the separation region, The solid heavy hydrocarbon and solids mixture is discharged out of the separation zone to mix the heavy hydrocarbons and solids A second step of recovering,
A method for recovering an oil content in crude oil sludge.   An inner cylinder in which an object supply port for discharging the object to be processed from the inside to the outside and supplying it to the separation region is formed, and the inner cylinder is provided outside the inner cylinder so as to surround the inner cylinder. The solid content discharge port for discharging the gas from the inside to the outside is formed, and is wound spirally around the outer cylinder for forming a separation region between the inner cylinder and the outer wall of the inner cylinder. A screw plate, a partition wall provided on one end side of the separation region, wherein a light discharge path is formed near the inner cylinder and a heavy discharge path is formed near the outer cylinder, 2. The crude sludge according to claim 1, wherein the second step is performed by supplying the heated and stirred processed product at 40 to 200 ° C. and centrifuging the decanter type centrifuge having Oil recovery method.