JP4376700B2 - Sludge treatment method - Google Patents

Description

  The present invention relates to a method for treating sludge, and more particularly to a technique for recovering oil contained in sludge with high efficiency when sludge accumulated in a crude oil tank or the like is treated.

  In a crude oil tank that stores crude oil, a paste-like substance called sludge is accumulated. The components of sludge accumulated in the crude oil tank include wax, asphaltenes, resins, saturated components, aromatics, etc. caused by “oil fraction”, water, iron (rust), earth and sand caused by “contaminants” When the sludge component ratio is seen, wax (oil) and moisture account for more than 80%. There is a general concern that such sludge has the following effects on equipment. That is, if sludge accumulates in the crude oil tank and is sent to the downstream process of refining the crude oil, it may cause a failure of the crude oil supply pump, clogging of the heat exchanger or filter, adverse effects on the catalyst in the reactor, etc. May attract you. Moreover, since the sludge accumulated on the tank bottom plate also causes corrosion, it is necessary to remove the sludge.

  A common method for removing sludge from crude oil tanks that could adversely affect the oil refining process is to install a spray nozzle inside the crude oil tank and inject crude oil at high pressure (Crude Oil Washing).

  However, there is a need for a method for removing sludge inside a crude oil tank more efficiently than simply injecting crude oil, and many proposals have been made so far. For example, in order to remove sludge more efficiently, an internal cleaning method for asphalt and black oil tanks using a cracked light oil produced in a fluid catalytic cracking device as a cleaning solvent is proposed instead of cleaning with crude oil (patent) Reference 1).

  Also, as a method of removing sludge in the crude oil tank and recovering oil from the removed sludge, heat medium oil is introduced at a volume ratio within a predetermined range with respect to the sludge in the crude oil tank, and sludge is removed with heat medium oil. There has also been proposed a method of recovering oil from a mixture of heat medium oil and sludge after melting and transferring to a separately connected separation tank and letting it stand in the separation tank (see Patent Document 2).

JP-A-6-126262 JP 2002-338969 A

According to the internal cleaning method described in Patent Document 1, since the decomposed light oil itself has a dissolving power that functions as a solvent, this dissolving power can be expected to promote the dissolution of oil in the sludge as compared with cleaning with crude oil. . However, this document does not discuss how to efficiently recover a large amount of oil contained in sludge.
In the oil recovery method described in Patent Document 2, the sludge is melted by using heat medium oil heated to some extent, and the oil content in the sludge is recovered. However, since heat medium oil heated to a specific temperature is used, facilities such as heat insulation are required.

  The present invention has been made in view of the above-mentioned conventional situation, and this sludge treatment that pulverizes and dissolves sludge in a crude oil tank and recovers oil contained in the sludge with high efficiency without requiring major equipment changes. It aims to provide a method.

  As a result of intensive studies on a method for easily removing sludge in a crude oil tank and a method for recovering oil from the removed sludge with high efficiency, the inventors have smashed and dissolved sludge with a specific oil, and then identified the sludge. Finds a way to reduce the amount of sludge that is finally handled as industrial waste by efficiently dissolving the oil contained in the sludge by stirring the sludge together with the oil of the oil, and recovering the oil from the sludge The present invention has been reached.

That is, the present invention provides the following sludge treatment method in order to achieve the above object.
(1) A sludge treatment method for recovering oil contained in sludge in a crude oil tank ,
(A) a sludge pulverization step of pulverizing the sludge by injecting the crude oil at a pressure ratio of 0.6 to 0.7 MPa at a volume ratio of 2 to 5 times with respect to the bulk sludge in the crude oil tank ;
(B) a sludge dissolution step of supplying at least a part of the sludge by supplying a cracked light oil obtained from a fluid catalytic cracking device to a pulverized sludge , or a solution containing A heavy oil ;
(C) a sludge of the crude oil tank, a sludge transfer step for unloading the second tank of small capacity than the crude oil tank,
(D) A sludge agitation step for agitating the sludge by adding a solution containing the cracked light oil obtained from the fluid catalytic cracking device in a volume ratio of 2 to 4 times to the sludge transferred to the second tank;
(E) and oil recovery step of said mixture of sludge and the solution was precipitated separated to recover the liquid fraction containing dissolved oil of the sludge, only including, the steps of said (a) ~ (e) is A sludge treatment method characterized by being performed at room temperature .

According to this sludge treatment method, crude oil is injected at a pressure ratio of 0.6 to 0.7 MPa in a volume ratio of 2 to 5 times with respect to the lump sludge in the crude oil tank , and the sludge in the crude oil tank is crushed. Later, the oil content in the sludge is dissolved with a cracked light oil obtained from the fluid catalytic cracking device or a solution containing heavy oil A , and this is transferred from the crude oil tank to the second tank having a smaller capacity, from the fluid catalytic cracking device. By adding the stirring solution containing the obtained cracked light oil at a volume ratio of 2 to 4 times to the transferred sludge and stirring, the sludge in the crude oil tank can be easily removed to the transfer destination tank, Since it is sufficiently stirred in the tank of the transfer destination, the oil content of the sludge is surely dissolved in the solution, and the amount of the remaining sludge can be reduced finally. Furthermore, since this process can be performed at normal temperature, oil contained in the sludge can be recovered with high efficiency without requiring any change in equipment.

(2) A sludge treatment method for recovering oil contained in sludge in a crude oil tank,
(A) a sludge pulverization step of pulverizing the sludge by injecting the crude oil at a pressure ratio of 0.6 to 0.7 MPa at a volume ratio of 2 to 5 times with respect to the bulk sludge in the crude oil tank;
(B) a sludge dissolution step of supplying at least a part of the sludge by supplying a cracked light oil obtained from a fluid catalytic cracking device to a pulverized sludge, or a solution containing A heavy oil;
(C) The sludge in the crude oil tank is transported from the crude oil tank to the second tank having a smaller capacity by the transfer pump provided in the crude oil tank and movable in the crude oil tank. A sludge transfer process,
(D) A sludge agitation step for agitating the sludge by adding a solution containing the cracked light oil obtained from the fluid catalytic cracking device in a volume ratio of 2 to 4 times to the sludge transferred to the second tank;
(E) an oil component recovery step of precipitating and separating a mixture of the sludge and the solution and recovering a liquid component containing the dissolved oil component of the sludge, and each of the steps (a) to (e) is performed at room temperature. The sludge processing method characterized by being performed by this.
  According to this sludge treatment method, crude oil is injected at a pressure ratio of 0.6 to 0.7 MPa in a volume ratio of 2 to 5 times with respect to the lump sludge in the crude oil tank, and the sludge in the crude oil tank is crushed. Later, the oil component in the sludge is dissolved with a cracked light oil obtained from a fluid catalytic cracking device or a solution containing heavy oil A, and this is installed in a truck that is disposed in the crude oil tank and movable in the crude oil tank. The dissolved liquid containing cracked light oil obtained from the fluid catalytic cracking device by transferring to the second tank having a smaller capacity from the crude oil tank by the transfer pump was added at a volume ratio of 2 to 4 times the sludge transferred. By stirring the oil, the sludge in the crude oil tank can be easily removed to the transfer destination tank and sufficiently stirred in the transfer destination tank, so that the oil in the sludge is surely dissolved in the solution. , It is possible to reduce the amount of sludge that end to remain. Furthermore, since this process can be performed at normal temperature, oil contained in the sludge can be recovered with high efficiency without requiring any change in equipment.

Further , according to the sludge treatment methods (1) and (2) , the most efficient pulverization treatment can be performed by supplying crude oil in a volume ratio of 2 to 5 times that of the sludge.

Further , according to the sludge treatment methods of (1) and (2) above, the dissolved light oil or A heavy oil obtained by the fluid catalytic cracking apparatus is contained in the solution, so that the dissolving power is increased due to the aromatic content contained in the dissolved liquid. Is increased, and more oil in the sludge can be dissolved.

Further , according to the sludge treatment methods of (1) and (2) above, the dissolved light oil or A heavy oil obtained by the fluid catalytic cracking apparatus is contained in the solution, so that the dissolving power is increased due to the aromatic content contained in the dissolved liquid. The oil content in the sludge can be dissolved more during stirring.

Moreover , according to the sludge treatment method of said (1) and (2), sludge processing can be implemented without requiring a heat retention installation because each process is performed at normal temperature. Moreover, a sludge transfer process etc. can also be easily performed manually.

According to the sludge treatment method of the present invention, a sludge pulverization step in which crude oil is injected at a pressure ratio of 0.6 to 0.7 MPa at a volume ratio of 2 to 5 times with respect to the lump sludge in the crude oil tank, and fluid contact The sludge in the crude oil tank can be easily removed by the sludge dissolution process using the dissolved light oil obtained from the cracking device or the cracked light oil containing A heavy oil , and the sludge is transferred from the crude oil tank to the second tank having a smaller capacity . By adding a solution containing cracked light oil obtained from a fluid catalytic cracker at a volume ratio of 2 to 4 times and stirring the sludge, the oil in the sludge can be dissolved and recovered with high efficiency, and finally industrial waste It becomes possible to reduce the amount of sludge.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a sludge treatment method according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic process chart showing a specific example of the sludge treatment method according to the present invention.
Schematically, a crude oil tank (first tank) 1 that performs cleaning has a plurality of (for example, around 20) injection devices 5, 5, 5 for injecting crude oil or a solution to be described later onto the floating roof portion 3. Are attached to a separate crude oil tank 7 or a solution tank (decomposed light oil or heavy oil A) 9, pumps P1, P2 and valves B1, B2. Connected through. Further, a recovery tank 11 that recovers the liquid in the crude oil tank 1 is connected to the crude oil tank 1 via a bubble B3 and a pump P3. The detailed configuration will be described in detail when explaining each process of the sludge treatment.

FIG. 2 shows a flowchart of the sludge treatment method according to the present invention. Hereinafter, each process will be sequentially described based on this flowchart.
First, prior to the sludge treatment, the crude oil tank 1 to be cleaned is filled with nitrogen to expel air. Thereby, the combustible vapor | steam density | concentration in the crude oil tank 1 becomes out of an explosion range.
<Sludge grinding process>
Next, the crude oil stored in another crude oil tank 7 or the crude oil present in the crude oil tank 1 is injected and supplied from the injection device 5 into the crude oil tank 1 to be cleaned. As injection conditions at this time, the pressure is about 0.6 to 0.7 MPa, the flow rate is about 150 to 200 kl / h, and the spraying is performed toward the sludge in the crude oil tank 1 for about 150 hours. Thereby, as shown in FIG. 3, the sludge S in the crude oil tank 1 is pulverized, and the sludge S is subdivided (step 1; hereinafter abbreviated as St1). Here, the sludge S is also dissolved in the crude oil.

Here, when the crude oil from the crude oil tank 7 is supplied by injection, the crude oil in the crude oil tank 7 is guided to the injector 5 by opening the discharge valve B1 of the crude oil tank 7 and driving the pump P1. In order to sufficiently pulverize the sludge S, it is preferable to add the crude oil at a volume ratio of 2 to 5 times the volume of the sludge S present in the crude oil tank 1. By introducing in this range, the sludge S is sufficiently pulverized, and the sludge dissolution in the sludge dissolution step which is the next step becomes good. If the crude oil is less than twice, the entire sludge S cannot be finely pulverized, and even if more than five times the crude oil is added, the pulverization effect does not increase, and the amount of recovered crude oil increases. The process is prolonged.
In parallel with this operation, the crude oil in which the sludge is dissolved is transferred to the recovery tank 11 by driving the pump P3 and operating the valves B3, B4, and B5.

<Sludge dissolution process>
Next, since the pulverized sludge S contains a large amount of oil, the oil in the sludge S is dissolved after pulverizing the sludge S by spraying crude oil (St2). At that time, as shown in FIG. 4, the sludge S pulverized with a solution containing hydrocarbon oil at a pressure of about 0.6 to 0.7 MPa and a flow rate of about 150 to 200 kl / h for about 50 hours. Spray on. As a result, the sludge S, which has been crushed and has an increased surface area, is efficiently dissolved in the solution.

As the hydrocarbon oil that is the main component of the solution used here, cracked light oil distilled off from a fluid catalytic cracking apparatus that performs catalytic cracking with a catalyst, or A heavy oil is preferably used. The aromatic component contained in the cracked light oil or A heavy oil has a strong dissolving power and a high effect of dissolving the oil component in the sludge, and therefore can be suitably used as a sludge solution.
The cracked light oil distilled from the fluid catalytic cracking unit is a fluid catalytic cracking method (UOP method, shell two-stage method, flexi cracking method, ultra ortho flow method, texaco method). , Distillate obtained using a solid acid catalyst (eg, silica / alumina, or silica / alumina blended with zeolite) by the Gulf method, the Altracite cracking method, the RCC method, the HOC method, etc. And a boiling point range of 160 to 380 ° C.

Heavy oil is classified into 1 type (A heavy oil), 2 types (B heavy oil), and 3 types (C heavy oil) according to kinematic viscosity, flash point, residual carbon content, etc., as defined in JIS K 2205. . A heavy oil is a flash point of 60 ° C or higher, a kinematic viscosity of 20mm ² / S or less at 50 ° C, a pour point of 5 ° C or less, a residual carbon content of 4% by mass or less, a water content of 0.3% by volume or less, an ash content Is a hydrocarbon oil of 0.05 mass% or less. A heavy oil is further subdivided into No. 1 with a sulfur content of 0.5% by mass or less and No. 2 with 2.0% by mass or less. No. 1 is used as the A heavy oil used in the sludge treatment method according to the present invention. No. 2 may be used.

<Sludge transfer process>
The sludge in the crude oil tank 1 immersed in the solution containing hydrocarbon oil by the above-described sludge dissolving step is softened by dissolving the oil in the sludge with the cracked light oil or the A heavy oil in the solution. After the sludge softening improves the sludge handling, the sludge is transferred from the crude oil tank 1 to another tank (second tank) (St3). Here, as an example, a case where sludge is manually removed using a transfer pump used for transferring powder or the like will be described. FIG. 5 shows how the sludge is transferred from the crude oil tank 1 to another tank.

First, the manhole 13 of the crude oil tank 1 is opened so that the worker can enter the interior of the crude oil tank 1, and the inside of the tank is sufficiently replaced with air. Thereafter, the sludge removal operation of transferring all the sludge existing in the crude oil tank 1 to another tank (sludge dissolution tank 15) is performed.
The transfer pump 17 used here is a pump that transfers solid matter containing oil, but a commercially available powder pump can be used. In order to easily transfer the sludge existing inside the tank, the transfer pump 17 is placed on a moving means such as a carriage 19 and a sludge transfer hose 23 is provided on the discharge nozzle 21 from which the sludge is discharged. An attached transfer unit 25 may be used. By using this transfer pump 17, it is possible to move freely inside the tank, and the working efficiency is improved. This sludge removal work can be automated by using a self-propelled robot or the like that can automatically draw and remove sludge, and the work cost can be further reduced.

<Sludge stirring process>
Next, the solution is added to the sludge transferred to the sludge dissolution tank 15 using the transfer pump 17 or the like and stirred (St4).
As shown in FIG. 5, the sludge dissolution tank 15 includes a stirrer 29 that agitates the sludge by rotating the blades 27 by the motor M, and adds and dissolves the solution to the transferred sludge Sa.

  The size of the sludge dissolution tank 15 can be arbitrarily selected with a smaller capacity than the crude oil tank 1, but a large dissolution tank requires a large agitator and a large transfer pump, leading to an increase in equipment and cost. The amount of sludge Sa to be stirred at one time is generally about 800 to 1200 kg, although it depends on the size of the crude oil tank 1 and the amount of sludge deposited. The stirring time is 20 to 40 minutes, preferably about 30 minutes, with respect to the amount of the sludge Sa. Even if stirring is performed for a longer time, there is no significant change in the dissolution rate of the sludge Sa. Moreover, it is preferable that the solution to be added contains a hydrocarbon oil having a volume 2 to 4 times that of the sludge Sa. And as for the rotational speed of the blade | wing 27 of the stirrer 29, 200-400 rpm is preferable.

  The dissolved hydrocarbon oil used in this stirring step is preferably a cracked light oil distilled from a fluid catalytic cracker. Decomposed light oil generally contains about 60 to 85% by volume of aromatics, has a high dissolving power due to the large amount of aromatics, and has a relatively high flash point of 60 to 75 ° C. Easy.

  Specifically, as shown in FIG. 1 and FIG. 6 (a), sludge is fed from the transfer unit 25 to the sludge dissolution tank 15 in which the stirrer 29 is installed, while from the solution tank 9 through the pump P4 and the valve B6. A solution containing hydrocarbon oil is added to the sludge dissolution tank 15, and the blades 27 are rotated by the drive of the motor M and stirred as shown in FIG. As a result, the oil content in the sludge Sa is further dissolved in the hydrocarbon oil of the solution, and the amount of sludge finally remaining is greatly reduced.

In addition, when the solution in the aforementioned sludge dissolving step is the same as the solution in the stirring step, the solution in the solution tank 9 can be used as it is. However, when the main component of the dissolving liquid in the sludge dissolving step is A heavy oil, a dissolving liquid tank 31 storing the dissolving liquid containing the decomposed light oil is connected separately, and the decomposed light oil is changed by switching the valves B6 and B7. The dissolved solution is supplied to the sludge dissolution tank 15.
Here, the sludge dissolution tank 15 is preferably a rounded cylindrical tank rather than a square tank with a square corner at the bottom because the stirring operation is performed up to the corner in the tank and the stirring efficiency is improved.

<Oil recovery process>
After adding the solution containing hydrocarbon oil to the sludge Sa and stirring, the stirrer 29 is stopped to precipitate and separate the mixture of the sludge Sa and the solution, and the resulting liquid is recovered.
That is, after the stirrer 29 is stopped, the sludge dissolution tank 15 is allowed to stand for about 5 to 10 minutes to precipitate the remaining sludge. As a result, as shown in FIG. 6 (c), the solution A containing the oil dissolved from the sludge Sa is separated from the remaining sludge and accumulated in the upper portion of the sludge dissolution tank 15, and dissolved in the lower portion. Residual sludge such as oil B (wax, asphaltene, resin, saturated content, aromatic content, etc.) and inorganic components C such as iron (rust) and earth and sand accumulate. Therefore, the valve B8 is opened, the pump P5 connected to the sludge dissolution tank 15 is driven, and only the oil component A separated in the upper part of the sludge dissolution tank 15 is transferred to the recovery tank 11.

  On the other hand, the sludge (B + C) remaining in the sludge dissolution tank 15 is packed in a drum or the like and transferred to be processed as industrial waste. The amount of the remaining sludge (B + C) is reduced by the amount corresponding to the dissolved oil from the amount of sludge Sa first transferred to the sludge dissolution tank 15. That is, the oil is further removed from the sludge after the previous sludge treatment, that is, the sludge Sa that has been transferred from the crude oil tank to the recovery tank and processed without stirring, and the amount of the remaining sludge is finally reduced. . Thereby, generation | occurrence | production of industrial waste can be reduced.

  Each step of the sludge treatment according to the present invention described above is performed at room temperature (25 ± 15 ° C.). Crude oil, cracked light oil, and heavy oil A used in this treatment method are handled at room temperature and do not require heat insulation equipment, and good sludge treatment results can be obtained even in this room temperature atmosphere. Here, cracked light oil is more expensive and causes economic loss than atmospheric residue oil, but in this treatment method, in order to reduce the amount of cracked light oil used, a small volume separate from that of crude oil tank 1 is required. Only the sludge is transferred to the tank, and the sludge is agitated in a plurality of times in this small capacity tank. Thereby, the quantity of the decomposition | disassembly light oil required at the time of stirring can be reduced.

  In addition, the crude oil tank 1 is also equipped with a mixer for stirring the crude oil to make the temperature and properties uniform, but this mixer is very large and is stirred using the mixer. In that case, a large amount of solution is required. Therefore, the method of stirring using a mixer cannot reduce the amount of cracked light oil used, and a sufficient stirring effect cannot be expected. Therefore, even if this method is used for stirring, the oil content of sludge is recovered. Efficiency is difficult to increase.

  In addition, when using high-temperature oil, it is necessary to insulate the pipes in order to prevent the temperature from being lowered, which increases the cost of heat insulation equipment, but this sludge treatment method is performed at room temperature. There is no need for heat insulation equipment. And this sludge processing method includes the process of transferring the sludge S inside the crude oil tank 1 to the sludge dissolution tank 15, and in this process, it is necessary for a machine or a person to enter the inside of the tank and collect the sludge. Therefore, in the method of treating sludge using high temperature oil, it is necessary to cool the inside of the tank in order to finally perform sludge collection work and internal inspection by humans (to enter the tank) Workability becomes worse. On the other hand, according to the present sludge treatment method, the workability of each process is not impaired without significant change of equipment.

  Then, the sludge accumulated in the crude oil tank 1 is transferred to the sludge dissolution tank 15 as a solid, and stirred together with the solution in the sludge dissolution tank 15 so that the sludge can be conveyed with high efficiency and the oil content contained in the sludge. Can be dissolved in the solution with high efficiency. As a result, the amount of finally remaining sludge can be greatly reduced, which can contribute to the reduction of industrial waste.

  The sludge treatment method according to the present invention is not limited to the above embodiment, and appropriate design changes can be made. For example, the same effect can be obtained by using other stirring means such as a vibration stirring device instead of using a stirrer using a rotary blade.

In order to verify the effect of the present invention, a comparison between the treatment result obtained by applying this sludge treatment method to the actual sludge treatment of a crude oil tank and the treatment result obtained by the conventional method will be described below.
The crude oil tank used for the comparison was a crude oil tank having a capacity of 130,000 kl, and the amount of sludge accumulated in this crude oil tank was about 4100 t.

(Sludge treatment of the present invention)
Sludge was pulverized by spraying crude oil at room temperature at a pressure of 0.7 MPa at a flow rate of about 180 kl / h for about 100 hours. Subsequently, A heavy oil at room temperature was sprayed at a pressure of 0.7 MPa at a flow rate of about 150 kl / h for about 50 hours to dissolve sludge. After dissolving the sludge, it entered the crude oil tank, and the dissolved sludge was transferred to a sludge dissolution tank using a powder dedicated pump. About 1 t of sludge was transferred to the sludge dissolution tank at a time, and about 3 kl of cracked light oil was fed at room temperature and stirred at a stirring speed of 245 rpm for about 30 minutes. After stirring, the mixture was allowed to stand for about 5 minutes to precipitate the sludge remaining in the sludge dissolution tank. The oil at the top of the sludge dissolution tank was transferred to the recovery tank, and the sludge that had settled at the bottom of the sludge dissolution tank was scraped out of the sludge dissolution tank and discarded as industrial waste.

(Sludge treatment by conventional method)
On the other hand, sludge is pulverized by spraying crude oil at room temperature at a pressure of 0.7 MPa at a flow rate of about 180 kl / h for about 100 hours to the above crude oil tank. Sludge was melted by spraying at a pressure of 7 MPa at a flow rate of about 150 kl / h for about 50 hours. After the sludge was dissolved, it entered the crude oil tank, the dissolved sludge was scraped and transferred to a recovery tank, and finally the remaining sludge was discarded as industrial waste.
The amounts of industrial waste obtained by these methods are shown in Table 1.

  As described above, according to the sludge treatment method of the present invention, the amount of sludge that becomes industrial waste can be reduced to about 1/4 of the conventional amount. As described above, the present sludge treatment method is performed after the sludge is softly dissolved by the sludge pulverization step by the injection of crude oil and the sludge dissolution step by the solution containing hydrocarbon oil, and the softened sludge is further transferred to the sludge dissolution tank. By adding a solution containing hydrocarbon oil and stirring, the oil in the sludge can be dissolved and recovered with high efficiency. Therefore, the oil recovery rate from the sludge becomes 99% or more, and the amount of sludge that becomes industrial waste can be greatly reduced.

It is a schematic process diagram which shows one specific example of the sludge processing method which concerns on this invention. The flowchart of the sludge processing method which concerns on this invention was shown. It is explanatory drawing which showed a mode that the crude oil was sprayed toward the sludge in a crude oil tank, and sludge was grind | pulverized. It is explanatory drawing which showed a mode that the solution was sprayed on sludge and the oil component in sludge was dissolved. It is explanatory drawing which shows a mode that sludge is transferred to another tank from a crude oil tank. It is a figure which shows the stirring process of sludge, (a) is a state which added the solution to the sludge dissolution tank in which the sludge was transferred, (b) is a state which drives the motor and is stirring, (c) is left still It is explanatory drawing which shows a mode that the remaining sludge is settled and separated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crude oil tank 3 Roof part 5,5, ... Injection apparatus 7 Crude oil tank 9 Dissolution tank 11 Recovery tank 13 Manhole 15 Sludge dissolution tank 17 Transfer pump 19 Cargo 21 Discharge nozzle 23 Hose 25 Transfer unit 27 Blade 29 Stirrer 31 Solution tank B1, B2, B3, B4, B5, B6, B7, B8 Valve P1, P2, P3, P4, P5 Pump S, Sa Sludge

Claims (2)

A sludge treatment method for recovering oil contained in sludge in a crude oil tank ,
(A) a sludge pulverization step of pulverizing the sludge by injecting the crude oil at a pressure ratio of 0.6 to 0.7 MPa at a volume ratio of 2 to 5 times with respect to the bulk sludge in the crude oil tank ;
(B) a sludge dissolution step of supplying at least a part of the sludge by supplying a cracked light oil obtained from a fluid catalytic cracking device to a pulverized sludge , or a solution containing A heavy oil ;
(C) a sludge of the crude oil tank, a sludge transfer step for unloading the second tank of small capacity than the crude oil tank,
(D) A sludge agitation step for agitating the sludge by adding a solution containing the cracked light oil obtained from the fluid catalytic cracking device in a volume ratio of 2 to 4 times to the sludge transferred to the second tank;
(E) and oil recovery step of said mixture of sludge and the solution was precipitated separated to recover the liquid fraction containing dissolved oil of the sludge, only including, the steps of said (a) ~ (e) is A sludge treatment method characterized by being performed at room temperature . A sludge treatment method for recovering oil contained in sludge in a crude oil tank,
(A) a sludge pulverization step of pulverizing the sludge by injecting the crude oil at a pressure ratio of 0.6 to 0.7 MPa at a volume ratio of 2 to 5 times with respect to the bulk sludge in the crude oil tank;
(B) a sludge dissolution step of supplying at least a part of the sludge by supplying a cracked light oil obtained from a fluid catalytic cracking device to a pulverized sludge, or a solution containing A heavy oil;
(C) The sludge in the crude oil tank is transported from the crude oil tank to the second tank having a smaller capacity by the transfer pump provided in the crude oil tank and movable in the crude oil tank. A sludge transfer process,
(D) A sludge agitation step for agitating the sludge by adding a solution containing the cracked light oil obtained from the fluid catalytic cracking device in a volume ratio of 2 to 4 times to the sludge transferred to the second tank;
(E) an oil component recovery step of precipitating and separating a mixture of the sludge and the solution and recovering a liquid component containing the dissolved oil component of the sludge, and each of the steps (a) to (e) is performed at room temperature. The sludge processing method characterized by being performed by this.

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