JP2022141390A - Heavy oil recovery method and recovery system - Google Patents

Abstract

To provide a method for efficiently recovering highly viscous heavy oil.SOLUTION: There is provided a recovery method of heavy oil, in which 10 to 45 wt.% of water and 0.5 to 5 wt.% of a surfactant are added to heavy oil, and the mixture is stirred to form an emulsion, thereby lowering the viscosity so as to recover the heavy oil.SELECTED DRAWING: Figure 1

Description

(1) Date of publication March 16, 2020 (2) Publisher The Japan Society of Mechanical Engineers (3) Publication name The Japan Society of Mechanical Engineers Kanto Branch 26th Annual General Meeting and Lecture Conference Proceedings, No. 200-1, 17B05

The present invention relates to a heavy oil recovery method and recovery system.

It is desirable to recover cargo oil and fuel oil loaded on ships that have sunk to the bottom of the sea due to maritime accidents, etc., as they may cause serious environmental damage if left unattended. In general, heavy oil loaded on ships such as tankers has a higher viscosity than kerosene or light oil, and the viscosity of the oil becomes even higher especially in a low-temperature environment such as in winter. Since heavy oil that has become highly viscous has poor fluidity, it is not easy to recover the heavy oil from the hull of a wrecked tanker or the like. In addition, if the hull is damaged due to grounding, etc., and seawater flows in, a water-in-oil (W/O) emulsion in which water particles are dispersed in the oil mixed with heavy oil and seawater will be used. becomes more viscous, and the viscosity becomes even higher. Due to the increase in viscosity due to the low temperature and the increase in viscosity due to W/O emulsion formation, it is assumed that recovery of heavy oil will be more difficult.

In general, in the event of an oil spill accident from a vessel such as a tanker, measures are taken such as placing an oil fence around the hull to prevent the spread of the spilled oil and mechanically recovering the oil with a recovery vessel. . In some cases, a dispersant is sprayed on the spilled oil to make the oil finer and decompose naturally.

A common method for recovering fuel oil and the like from a stranded ship or a sunken ship is to use an oil recovery pump to suck and recover the oil and the like in the tank. As described above, if the water depth during recovery is deep, the viscosity of the fuel oil or the like increases as described above, making the work difficult. Therefore, measures such as heating the fuel oil with steam or the like to lower its viscosity and make it fluid before recovering it are taken. However, steam has limitations in its handling, and development of a new recovery method is desired.

A technique for reducing the viscosity of a high-viscosity substance having a viscosity equivalent to that of heavy oil by making use of pressure waves caused by boiling of a liquid or rapid expansion of a vapor of a liquid has been disclosed (Patent Document 1). This technique enables efficient recovery of highly viscous substances such as heavy oil.

On the other hand, techniques for emulsifying an oil phase and an aqueous phase by using a surfactant have been disclosed (Patent Document 2, Non-Patent Document 1). Also, a technique for changing the viscosity of the oil phase by emulsification has been disclosed (Non-Patent Document 2).

JP 2017-170407 A Japanese Patent Publication No. 2018-536755

"Physicochemical Study on the Preparation and Physical Properties of Macro- and Micro-emulsions Using Various Surfactants", Cosmetology Research Promotion Foundation Research Report Vol.12 August 1994 "Influence of Droplet Diameter on Viscosity Characteristics of Emulsion", Research Report of Miyazaki Prefectural Industrial Technology Center/Miyazaki Prefectural Food Development Center, 2008, No. 53, pp 13-18

There is a need for improved techniques for rapid recovery of heavy oil left in the tanks of submerged ships in low temperature environments such as deep sea. Therefore, it is desired to develop a technology to prevent contamination of the marine environment due to spillage by recovering heavy oil from sunken ships by reducing the viscosity of heavy oil in some way to make it fluid. there is

A recovery method for emulsifying and recovering heavy oil corresponding to claim 1 includes water of 10% by weight or more and 45% by weight or less of the heavy oil and an interface of 0.5% by weight or more and 5% by weight or less. It is characterized by adding an activator and stirring to emulsify, thereby reducing the viscosity and recovering.

Here, it is preferable to recover the heavy oil whose viscosity has decreased and fluidity has increased through a pipe by means of a pump.

Further, it is preferable that the heavy oil, the water, and the surfactant are also stirred by the pump means.

Also, the heavy oil is preferably a substance having a viscosity of 50 mPa·s or more.

Also, it is preferable to pre-heat the heavy oil to reduce the viscosity before adding the water and the surfactant.

Further, it is preferable that the surfactant has low hydrophilicity and high lipophilicity. Specifically, the numerical value (HLB) indicating the balance between the hydrophilicity and the lipophilicity of the surfactant is preferably less than 20.

Further, it is preferable to stir the heavy oil after it is pulverized by spraying the water and the surfactant.

Moreover, it is preferable that the recovery is recovery from a heavy oil tank containing the heavy oil in a sunken ship existing under water.

A recovery system for emulsifying and recovering heavy oil corresponding to claim 10 includes a pipe in which the heavy oil flows, water in an amount of 10% by weight or more and 45% by weight or less with respect to the heavy oil, Adding means for adding a surfactant of 0.5% by weight or more and 5% by weight or less, stirring means for stirring the heavy oil, the water, and the surfactant, and stirring by the stirring means to form an emulsion and pump means for recovering the heavy oil that has been converted.

Here, it is preferable that the addition means has a high-pressure injection nozzle for injecting the water and the surfactant toward the heavy oil flowing inside the pipe.

Further, the adding means has a mixing tank for pre-mixing the water and the surfactant, and the liquid mixture of the water and the surfactant mixed in the mixing tank is injected at high pressure via a high-pressure pump. It is preferred to lead to a nozzle.

In addition, it is preferable that the agitating means has a agitator having a propeller disposed inside the pipe on the downstream side of the adding means.

Further, as the stirring means, it is preferable that the pump means also has a stirring function.

Further, it is preferable to provide preheating means for preheating the heavy oil at the tip of the pipe that sucks the heavy oil.

Further, a flow rate detecting means for detecting a flow rate of the heavy oil passing through the inside of the pipe, and an addition amount of the water and the surfactant by the adding means is detected by the flow rate detecting means. It is preferable to provide control means for controlling according to the flow rate.

Further, the pipe is attached to a heavy oil tank containing the heavy oil in a sunken ship existing under the water surface, and the adding means, the stirring means and the pump means are connected to the pipe on the side of the heavy oil tank. is provided at the tip of the tank, and the recovered heavy oil is preferably conveyed to and stored in a heavy oil recovery ship facing the water surface.

Moreover, it is preferable that the heavy oil recovery ship has transfer means for transferring the contained heavy oil to a heavy oil carrier.

According to the recovery method of emulsifying and recovering heavy oil of the present invention, 10% to 45% by weight of water and 0.5% to 5% by weight of surface activity with respect to the heavy oil By adding an agent, stirring, and emulsifying to lower the viscosity and recovering the heavy oil, the viscosity of the heavy oil is lowered, and processing such as recovery of the heavy oil can be facilitated. In particular, when the heavy oil, water, and surfactant are mixed and emulsified, the viscosity of the heavy oil drops rapidly and emulsification can be performed within the range where transition occurs, so the effect of effectively reducing the viscosity is large. . In addition, it can lead to efficiency improvement of work, cost reduction, and environmental protection.

Here, by recovering the heavy oil whose viscosity has decreased and fluidity has increased through a pipe by means of a pump, the heavy oil whose viscosity has decreased can be recovered more quickly. be able to.

Further, the heavy oil, the water, and the surfactant are stirred by the pump means, so that the heavy oil, the water, and the surfactant are stirred by the pump means for recovering the heavy oil. Agitation of the surfactant can be efficiently performed. Moreover, means for stirring the heavy oil, the water, and the surfactant can be simplified.

Further, the heavy oil is a substance having a viscosity of 50 mPa·s or more, so that the heavy oil having a relatively high viscosity corresponding to the “highly viscous substance” can be easily recovered.

In addition, before adding the water and the surfactant, the heavy oil is heated in advance to reduce the viscosity, thereby further reducing the viscosity of the heavy oil and recovering the heavy oil. can be processed more easily.

Further, the surfactant has low hydrophilicity and high lipophilicity, and specifically, the numerical value (HLB) showing the balance between the hydrophilicity and the lipophilicity of the surfactant is less than 20. By promoting the emulsification of the heavy oil, the viscosity of the heavy oil can be more effectively reduced.

In addition, after the heavy oil is finely divided by spraying the water and the surfactant, the heavy oil is stirred, thereby promoting emulsification of the heavy oil and increasing the viscosity of the heavy oil more effectively. can be lowered.

In addition, since the recovery is recovery from a heavy oil tank containing the heavy oil in a wreck existing under water, the recovery of the heavy oil from the wreck can be performed more quickly. .

According to the recovery system for emulsifying and recovering heavy oil of the present invention, a pipe in which the heavy oil flows, 10% by weight or more and 45% by weight or less of water with respect to the heavy oil, and 0 addition means for adding 5% by weight or more and 5% by weight or less of a surfactant, stirring means for stirring the heavy oil, the water and the surfactant, and stirring by the stirring means to emulsify. By providing the pump means for recovering the heavy oil, the viscosity of the heavy oil can be reduced, and processing such as recovery of the heavy oil can be facilitated. In particular, when the heavy oil, water, and surfactant are mixed and emulsified, the viscosity of the heavy oil drops rapidly and emulsification can be performed within the range where transition occurs, so the effect of effectively reducing the viscosity is large. . In addition, it can lead to efficiency improvement of work, cost reduction, and environmental protection.

Here, the addition means has a high-pressure injection nozzle for injecting the water and the surfactant toward the heavy oil flowing inside the pipe, so that the heavy oil is finely divided. Emulsification is promoted, and the viscosity of the heavy oil can be reduced more effectively.

Further, the adding means has a mixing tank for pre-mixing the water and the surfactant, and the liquid mixture of the water and the surfactant mixed in the mixing tank is injected at high pressure via a high-pressure pump. By guiding the water and the surfactant through the nozzle, the mixing ratio of the water and the surfactant can be appropriately adjusted before being added to the heavy oil. This makes it possible to effectively emulsify the heavy oil.

In addition, as the stirring means, a stirrer having a propeller disposed inside the pipe on the downstream side of the adding means promotes emulsification of the heavy oil and increases the viscosity of the heavy oil. can be effectively reduced.

Further, as the stirring means, the pump means also has a stirring function, so that the heavy oil, the water, and the surfactant are efficiently stirred by the pump means for recovering the heavy oil. can be done. Moreover, means for stirring the heavy oil, the water, and the surfactant can be simplified.

Further, by providing a preheating means for preheating the heavy oil at the tip of the pipe that sucks the heavy oil, the viscosity of the heavy oil is further reduced, and processing such as recovery of the heavy oil is facilitated. can be made easier.

Further, a flow rate detecting means for detecting a flow rate of the heavy oil passing through the inside of the pipe, and an addition amount of the water and the surfactant by the adding means is detected by the flow rate detecting means. By providing the control means for controlling according to the flow rate, it is possible to appropriately adjust the amounts of the water and the surfactant to be added according to the properties of the heavy oil and then add them to the heavy oil. can. Thereby, the emulsification of the heavy oil for reducing the viscosity can be effectively realized.

Further, the pipe is attached to a heavy oil tank containing the heavy oil in a sunken ship existing under the water surface, and the adding means, the stirring means and the pump means are connected to the pipe on the side of the heavy oil tank. is provided at the tip of the wreck, and the recovered heavy oil is conveyed to and stored in a heavy oil recovery ship facing the water surface, so that the recovery of the heavy oil from the wreck can be performed more quickly. can.

Further, the heavy oil recovery ship has transfer means for transferring the stored heavy oil to a heavy oil carrier, thereby recovering the heavy oil by the heavy oil recovery ship, The heavy oil can be efficiently transported by the heavy oil carrier.

It is a figure which shows the usage condition of the recovery system of the heavy oil in embodiment of this invention. 1 is an external view showing the configuration of an emulsion unit according to an embodiment of the present invention; FIG. 1 is a conceptual diagram showing the configuration of an emulsion unit according to an embodiment of the present invention; FIG. It is a figure which shows the example of arrangement|positioning of the injection nozzle in embodiment of this invention. It is a figure which shows the example of arrangement|positioning of the stirrer in embodiment of this invention. FIG. 4 is a diagram showing changes in viscosity of heavy oil due to the addition of water and surfactant in the embodiment of the present invention; It is a figure which shows the mode of mixing of water and heavy oil by addition of water and an oil treatment agent in embodiment of this invention. It is a figure which shows the mode of mixing of water and heavy oil by addition of water and surfactant in embodiment of this invention. FIG. 4 is a diagram showing changes in viscosity of heavy oil due to the addition of water and surfactant in the embodiment of the present invention;

A heavy oil recovery system 100 according to an embodiment of the present invention, as shown in FIG. used for In addition, the heavy oil that has flowed out of the heavy oil tank of the vessel 300 to be recovered and has accumulated in the cabin or the like can also be recovered. Furthermore, it can be applied to recovery of heavy oil from fuel oil tanks of the recovery target ship 300, oil tanks that have fallen into the water, broken oil transport pipes in the water, etc., and can be applied to uses other than underwater.

The heavy oil recovered by the heavy oil recovery system 100 may be stored in a tank provided on the recovery ship 200 and transported, or may be stored in a tank provided on the heavy oil carrier 400. It may be transferred.

The heavy oil recovery system 100 supplies water and a surfactant to the heavy oil and mixes the emulsified oil before recovery. As will be described later, by emulsifying the heavy oil, the viscosity of the heavy oil can be reduced and the recovery of the heavy oil becomes easier.

In the present embodiment, heavy oil is oil with a high specific gravity of about 0.82 to 0.95 and high viscosity, such as fuel oils such as A heavy oil, B heavy oil and C heavy oil. Heavy oil includes heavy oil and asphalt. Heavy oil falls under the category of "highly viscous substances" in the "Ministerial Ordinance Concerning Pretreatment Methods for Discharge of Hazardous Liquid Substances from Ships" (Prime Minister's Office/Ministry of Transport Ordinance No. 1 of 1987). High-viscosity substances refer to X-class substances listed in Appended Table 1 of the Enforcement Order of the Law Concerning the Prevention of Marine Pollution and Maritime Disasters or Y-class substances listed in Appended Table 2, and the temperature at the time of unloading is , which has a viscosity of 50 mPa·s or more. Also, the following URL %8F%9B%E7%AE%97%E8%A1%A8%27), according to the viscosity conversion table obtainable, "high viscosity" means 70 mmPa·s or more. In the present embodiment, heavy oil is oil having a viscosity of 50 mPa·s or more, which is defined as a “highly viscous substance” defined by ministerial ordinance.

The heavy oil recovery system 100 includes an emulsion unit 102, a recovery pipe 104, a pump 106, a liquid supply pipe 108 and an electric wire 110, as shown in the external view of FIG.

The emulsion unit 102 is installed in the heavy oil tank of the recovery target ship 300 . Further, when the emulsion unit 102 cannot be installed in the heavy oil tank of the recovery target ship 300, as shown in FIG. A recovery hose or the like may be extended from the heavy oil tank 300 to the emulsion unit 102 .

The emulsion unit 102, as shown in the cross-sectional view of FIG. Configured. The emulsion unit 102 is used to emulsify the heavy oil to increase fluidity. The liquid supply pipe 12 , the injection nozzle 14 and the pump 16 function as adding means for adding water and surfactant to the heavy oil in the heavy oil recovery system 100 . The injection nozzle 14 and the stirrer 18 also function as stirring means for stirring and mixing the heavy oil, water, and surfactant in the heavy oil recovery system 100 .

The main body 10 is a housing for arranging the injection nozzle 14, the stirrer 18, the temperature sensors 20a and 20b, the preheating means 22, and the like in the emulsion unit 102. As shown in FIG. In the present embodiment, the main body 10 has a tubular shape, and collects heavy oil through an internal space.

It is preferable to provide flanges 10a and 10b at the front end and the rear end of the main body 10, respectively. By providing the flange 10a at the tip, it becomes possible to attach a recovery hose or the like from the emulsion unit 102 and recover the heavy oil from a position farther than the position where the emulsion unit 102 is installed. By providing the flange 10b at the rear end, the recovery pipe 104 can be connected from the emulsion unit 102 to the recovery vessel 200. FIG.

The liquid supply pipe 12 is a pipe for supplying water and surfactant within the emulsion unit 102 . The liquid supply pipe 12 is connected to a liquid supply pipe 108 that connects a water tank and a surfactant tank provided on the recovery vessel 200 to the emulsion unit 102 . That is, the liquid supply pipe 12 connects from the liquid supply pipe 108 to the injection nozzle 14 in the emulsion unit 102 .

In this embodiment, water and surfactant are separately supplied from the recovery vessel 200, and a mixing tank 12a is provided in front of the injection nozzle 14 to mix the water and the surfactant in the mixing tank 12a. In this case, a flow meter (not shown) for measuring the flow rate of water and surfactant is provided in front of the mixing tank 12a, and the mixing ratio of water and surfactant is controlled according to the measured value of the flow meter. should be However, the present invention is not limited to this, and a liquid mixture of water and surfactant mixed at a predetermined mixing ratio in the recovery vessel 200 may be supplied to the injection nozzle 14 . Alternatively, an injection nozzle 14 for separately injecting water and a surfactant may be provided, and the water and the surfactant may be separately injected from the injection nozzle 14 . In this case, a flow rate control valve may be provided on the injection nozzle 14 side for adjusting the mixing ratio of the water to be injected and the surfactant. Furthermore, the water and the surfactant may be guided separately to the injection nozzle 14, mixed by the injection nozzle 14, and injected.

The temperature at which the mixture of water and surfactant is sprayed ranges from a temperature close to room temperature (20°C ± 5°C), which is higher than the temperature of heavy oil, to about 60°C (the temperature at which heavy oil is heated when it is transferred, etc.). , and it is preferable to inject. The temperature control of the mixed liquid can be realized by a heater provided in the mixing tank 12a, a heating means provided in the liquid supply pipe 12, or the like.

The injection nozzle 14 is a means for injecting water and surfactant to the heavy oil inside the main body 10 . It is preferable that each of the injection nozzles 14 can be opened and closed by a control signal from the recovery ship 200 . For example, it is preferable to provide a motor-operated valve in the injection nozzle 14 and perform control to open and close the solenoid valve by a control signal from the recovery ship 200 . By injecting water and a surfactant from the injection nozzle 14 onto the heavy oil, the heavy oil can be made finer. This makes it easier to agitate the heavy oil, water, and surfactant, and promotes emulsification of the heavy oil.

Here, the injection nozzle 14 is preferably a high-pressure injection nozzle. By using the injection nozzle 14 as a high-pressure injection nozzle, the heavy oil can be made finer by injecting water and surfactant into the heavy oil at a high pressure. Therefore, emulsification of heavy oil with water and a surfactant can be promoted more.

As shown in FIG. 4, it is preferable to arrange a plurality of injection nozzles 14 at even angles along the inner periphery of the main body 10 so that water and surfactant can be injected into the main body 10. is. FIG. 4A shows an example in which injection nozzles 14 are arranged at intervals of 60° along the inner circumference of the cylindrical main body 10. FIG. FIG. 4(b) shows an example in which injection nozzles 14 are arranged at intervals of 90° along the inner periphery of the main body 10 in the shape of a rectangular tube. It is preferable that the injection angle of the water and the surfactant from the injection nozzle 14 is, for example, 60° or more.

The mixing ratio and injection amount of water and surfactant are preferably adjusted by proportional control or PID control based on the flow rate and flow velocity of the heavy oil inside the main body 10 . The flow rate and flow velocity of the heavy oil can be measured by providing a flow meter 24, which will be described later, on the main body 10. FIG. In addition, the flow rate and flow velocity of the heavy oil can be estimated from the pressure difference between the pressure values of the heavy oil by providing a plurality of pressure gauges in the main body 10. It may be estimated from the relationship, or estimated from the relationship between the discharge amount of heavy oil and time. As control of the injection amount of water and surfactant, for example, when the viscosity of heavy oil is estimated to be 100 mPa s or less from the flow rate and flow velocity of heavy oil, water and surface active agent from the injection nozzle 14 Control such as stopping injection of the agent may be performed. Further, control may be performed so as to change the mixing ratio of water and surfactant according to the viscosity of the heavy oil.

Temperature sensors 20a and 20b, which will be described later, may be used to measure the temperature of the heavy oil before and after emulsification, and the mixture ratio and injection amount of water and surfactant may be adjusted by PID control or the like according to the measured temperature. For example, when the temperature of the heavy oil is above a predetermined temperature, injection of water and surfactant from the injection nozzle 14 is stopped, and when the temperature is below a predetermined temperature, the injection amount of water and surfactant is controlled. It is also possible to perform control such as injecting the water and surfactant from the injection nozzle 14 at the beginning. Further, control may be performed so as to change the mixing ratio of water and surfactant according to the temperature of the heavy oil.

The pump 16 is provided in the middle of the liquid supply pipe 12 and is means for applying pressure to the water and surfactant supplied to the injection nozzle 14 . The pump 16 is preferably configured so that the pressure applied to the water and surfactant can be adjusted by control signals from the recovery vessel 200 . However, since it is preferable that the water and surfactant injected from the injection nozzle 14 have high pressure, the pump 16 is preferably a high-pressure pump. In this embodiment, the pump 16 is provided outside the main body 10 , but the pump 16 may be provided inside the main body 10 .

The agitator 18 is means for agitating and mixing the heavy oil, water, and surfactant within the main body 10 . The stirrer 18 can be configured to include a motor and a propeller. The agitator 18 agitates the water and surfactant injected into the main body 10 from the injection nozzle 14 and the heavy oil flowing through the main body 10 by rotating the prober with a motor. This emulsifies the heavy oil, water and surfactant.

As shown in the cross-sectional view of FIG. 5A, the stirrer 18 preferably has propellers provided at equal angles (every 120° in the drawing) along the inner circumference of the cylindrical main body 10 . Further, as shown in the cross-sectional view of FIG. 5(b), it is preferable to provide propellers over the opposing inner surfaces of the main body 10 in the shape of a rectangular tube. However, the arrangement of the propellers of the stirrer 18 is not limited to these examples, as long as the heavy oil, water, and surfactant are appropriately stirred within the main body 10 .

The stirrer 18 is preferably provided downstream of the injection nozzle 14 along the flow direction of the heavy oil in the main body 10 . By arranging the stirrer 18 downstream of the injection nozzle 14, the heavy oil, water and The surfactant can be efficiently stirred.

The stirrer 18 may not be provided if the heavy oil, water, and surfactant can be sufficiently stirred and emulsified by jetting the water and the surfactant from the jet nozzle 14 or by the pump 106, which will be described later.

Temperature sensors 20 a and 20 b are provided to measure the temperature of heavy oil in emulsion unit 102 . The temperature sensor 20 a is arranged upstream of the injection nozzle 14 along the flow direction of the heavy oil in the main body 10 . The temperature sensor 20 b is arranged downstream of the stirrer 18 along the flow direction of the heavy oil in the main body 10 . The temperature of the heavy oil measured by the temperature sensors 20 a and 20 b is used to control emulsification of the heavy oil in the emulsion unit 102 . The temperature of the heavy oil measured by the temperature sensors 20a and 20b is transmitted to the recovery ship 200 by wire or wirelessly.

The preheating means 22 is a means for preheating the heavy oil flowing through the body portion 10 . The preheating means 22 is preferably arranged upstream of the injection nozzle 14 along the flow direction of the heavy oil in the main body 10 . A high-frequency heating device, for example, can be applied to the preheating means 22 . In the high-frequency heating device, a cylindrical heating coil is installed near the suction area at the tip of the main body 10, and the pipe is heated to raise the temperature, thereby removing the heavy oil inside the main body 10. It can be configured to heat. A heating device using steam, for example, can be applied to the preheating means 22 . The heating device using steam can be configured to heat water in the external environment to steam using an electric heater or the like, and directly inject the steam into the heavy oil near the suction area at the tip of the main body 10 . A heating device using steam is preferably used as an auxiliary high-frequency heating device in the case of heavy oil or the like mixed with water in a relatively shallow water depth to form a W/O type emulsion. However, the preheating means 22 is not limited to these, and an electric heater, a radiation heater, or the like may be applied. The heating temperature of the preheating means 22 is controlled by a control signal from the recovery vessel 200 . For example, it is preferable to control the temperature of the preheating means 22 according to the temperature measured by the temperature sensor 20a. Also, for example, it is preferable to control the temperature of the preheating means 22 according to the temperature measured by the temperature sensor 20b.

By preheating the heavy oil with the preheating means 22, the viscosity of the heavy oil can be reduced. In addition, emulsification of heavy oil can be promoted. In particular, when the heavy oil with a viscosity of 800 mPa·s and the heavy oil with a viscosity of 3000 mPa·s are to be recovered, the combined use of preheating by the preheating means 22 makes recovery easier.

The flowmeter 24 measures and outputs the flow rate and flow velocity of the heavy oil in the main body 10 . The flow rate and flow velocity measured by the flow meter 24 can be used to control the mixing ratio and injection amount of water and surfactant. Also, the flow rate and flow velocity measured by the flow meter 24 may be used to control the stirring by the stirrer 18 and the preheating of the heavy oil by the preheating means 22 . The flow rate and flow velocity of the heavy oil measured by the flow meter 24 are transmitted to the recovery vessel 200 by wire or wirelessly.

The recovery pipe 104 is a pipe for connecting the emulsion unit 102 and the recovery vessel 200 to flow the heavy oil. The tip of the recovery pipe 104 is connected to the flange 10 b on the rear end side of the main body 10 . The rear end of the recovery pipe 104 is connected to a pipe for sending the heavy oil to the recovery tank of the recovery vessel 200 or further to the recovery tank of the heavy oil carrier 400 .

Pump 106 is a means for applying pressure to the heavy oil. The pump 106 can be, for example, but not limited to, a jet pump or an ejector (vacuum) pump. The ejector pump includes a heating part and a jet part, and by ejecting heated working oil as steam at high speed, the fluid on the high vacuum side is involved in the ejected steam from the upper jet part to the lower jet part. It is a pump that compresses the fluid by transporting it and exhausts it from the exhaust port. When a jet pump or an ejector (vacuum) pump is used, the pump 106 and the emulsion unit 102 can be combined, and the injection nozzle 14 can also be combined. By using a jet pump or an ejector (vacuum) pump in this way, it is possible to integrate a stirring function, a pump function, and an injection (addition) function. In addition, as the driving fluid, a mixture of water and surfactant pressurized by the pump 16, water and surfactant separately supplied, pressurized water, and heating separately generated are also used. It can be steam or the like. The pump 106 is preferably arranged downstream of the injection nozzle 14 of the emulsion unit 102 along the flow direction of the heavy oil. The pump 106 is provided, for example, at the tip or in the middle of the recovery pipe 104 . By pressurizing the heavy oil with the pump 106, a flow is formed in the heavy oil from the emulsion unit 102 to the recovery vessel 200 via the recovery pipe 104, and the heavy oil is recovered. Also, the pump 106 may be used as one of stirring means for stirring the heavy oil, water, and surfactant within the main body 10 . The rating of the pump 106 may be appropriately determined according to the type and amount of heavy oil to be recovered.

The liquid supply pipe 108 is a pipe for supplying water and surfactant to the emulsion unit 102 . The liquid supply pipe 108 is connected from the water tank and surfactant tank provided on the recovery ship 200 to the liquid supply pipe 12 of the emulsion unit 102 .

The electric wire 110 is an electric wiring that connects the emulsion unit 102 and the recovery vessel 200 . Electrical line 110 includes power wiring that supplies power to emulsion unit 102 . Electrical line 110 also includes communication wiring for communication between emulsion unit 102 and recovery vessel 200 . That is, the electric line 110 is used to transmit control signals for controlling the injection nozzle 14 , the pump 16 and the stirrer 18 from the recovery vessel 200 to the emulsion unit 102 . Also, the electric line 110 is used to transmit information such as the temperature measured by the temperature sensors 20 a and 20 b and the flow rate and flow velocity of the heavy oil measured by the flow meter 24 to the recovery vessel 200 .

The heavy oil recovery system 100 is configured as described above. In the heavy oil recovery system 100, the heavy oil is emulsified by mixing the heavy oil with water and a surfactant to reduce the viscosity of the heavy oil, and then the heavy oil is recovered.

[Emulsification of heavy oil]
A method for emulsifying heavy oil using water and a surfactant will be described below. In the present invention, it was found that when water and a surfactant are mixed with a heavy oil in a predetermined ratio to form an emulsified mixture, a transition occurs in which the viscosity of the heavy oil sharply decreases.

Surfactants are used to emulsify the recovered heavy oil. A surfactant is a substance that has a water-friendly portion (hydrophilic group) and an oil-friendly portion (lipophilic group/hydrophobic group) in its molecule. Surfactants are sometimes referred to as amphipathic molecules. The surfactant in the present embodiment is preferably one that is relatively soluble in water, and more preferably has low hydrophilicity and high lipophilicity. Examples of surfactants include alkylsulfonic acids and polyethylene glycol fatty acid esters. Alkyl sulfonic acid is an anionic surfactant with very high wetting and penetrating power, and is excellent in acid resistance and hard water resistance, and is used as a penetrant and dispersant. Alkyl sulfonic acid is sometimes referred to as diethylhexyl sulfosuccinate in the labeling name of cosmetic ingredients, and examples thereof include NIKKOL OTP-75 (manufactured by Nikko Chemicals). The HLB value of NIKKOL OTP-75 is 20 or more (calculated value). Polyethylene glycol fatty acid esters are substances obtained by addition polymerization of ethylene oxide to fatty acids, and are used as hydrophilic emulsifiers and emulsifiers for cleansing oils. Polyethylene glycol fatty acid esters are sometimes called lauric acid PEG-10 in cosmetic ingredient labeling names, and examples include NIKKOL MYL-10 (manufactured by Nikko Chemicals). The HLB value of NIKKOL MYL-10 is 12.5. The HLB value is a value that indicates the balance between the hydrophilicity and lipophilicity of a surfactant to water and oil (a water-insoluble organic compound).

FIG. 6 shows the results of measurement of changes in viscosity of heavy oil (mixed liquid) when a small amount of surfactant and water are added to heavy oil and the mixture is stirred. In FIG. 6, the horizontal axis indicates the weight ratio of water to the weight of heavy oil, and the vertical axis indicates the viscosity of the mixture. The viscosity of the heavy oil (mixed liquid) was confirmed by the difference between the measured values of the pressure gauges installed at two points of the pipe in the experimental apparatus, the current value of the pump, and the discharge amount of the recovered heavy oil. In addition, heavy oil with a viscosity of 1000 mPa·s was used in the test.

In FIG. 6, Case 1 (circle) is when only water is added to heavy oil, Case 2 (square) is when water and an existing oil treatment agent are added to heavy oil, Case 3 (triangle) Mark) is when water and surfactant S1 (NIKKOL OTP-75) are added to heavy oil, Case 5 (diamond mark) is water and surfactant S2 (NIKKOL MYL-10) for heavy oil is added. In Case 2, 10% by weight of oil dispersant is added to heavy oil, in Case 3, 2% by weight of surfactant S1 is added to heavy oil, and in Case 5, water and surfactant are added to heavy oil. 2% by weight of S2 was added.

FIG. 7 is a photographed image showing how heavy oil and water are mixed when water and an existing oil treatment agent (10% by weight) are added to heavy oil in Case 2. FIG. In the photographed image of FIG. 7, the dark black area indicates water, and the light gray area indicates heavy oil. FIG. 8 is a photographed image showing how heavy oil and water are mixed when water and surfactant S2 (2% by weight) are added to heavy oil in Case 5. As shown in FIG. In the photographed image of FIG. 8, the dark black area indicates water, and the light gray area indicates heavy oil.

As shown in Cases 3 and 5 of FIG. 6, when heavy oil is mixed with water and surfactant S1 or surfactant S2 to form an emulsified mixture, a transition occurs in which the viscosity of the mixture rapidly decreases. rice field.

It was also found that, as an additive to be added to heavy oil, using only a surfactant is more efficient for emulsification than using an oil treatment agent containing a surfactant. In particular, if the conditions of the oil dispersant fluctuate slightly, the weight ratio of water that lowers the viscosity will exceed 45% by weight. There is a problem that the amount of emulsion to be recovered becomes very large and recovery becomes difficult. In this regard, the amount of surfactant added and the amount of water required for emulsification are small, and recovery is efficient.

In addition, as the type of surfactant, it is suitable for emulsifiers or dispersants, and is less hydrophilic than surfactant S1 (NIKKOL OTP-75), which has an HLB value of 20 or more. NIKKOL MYL-10) was more efficient for emulsification to reduce the viscosity of heavy oil (mixed liquid).

Next, the influence of the addition ratio of the surfactant was confirmed. FIG. 9 shows the heavy oil ( The results of examining the change in viscosity of the mixed liquid) are shown. In FIG. 9, the horizontal axis indicates the weight ratio of water to the weight of heavy oil, and the vertical axis indicates the viscosity of the mixture.

In FIG. 9, Case 4 (triangle marks) is when 1% by weight of surfactant S2 is added to heavy oil, and Case 5 (diamond marks) is 2% by weight of surfactant S2 to heavy oil. Case 6 (square mark) shows the case where 4% by weight of surfactant S2 is added to the heavy oil.

As shown in FIG. 9, when the surfactant S2 was added in an amount of 1% by weight, the viscosity of the heavy oil (mixed liquid) decreased sharply when the ratio of water to the heavy oil was 0.35 or more. Further, when the surfactant S2 was added in an amount of 2% by weight, the viscosity of the heavy oil (mixed liquid) decreased sharply when the ratio of water to the heavy oil was set to 0.22 or more. When the surfactant S2 was added in an amount of 4% by weight, the viscosity of the heavy oil (mixed liquid) decreased sharply when the ratio of water to the heavy oil was 0.16 or more.

Based on these experimental results, it was found that the addition ratio of surfactant to heavy oil was 0.5% by weight or more and 5% by weight or less, and the addition ratio of water was 10% by weight or more and 45% by weight or less. It was confirmed that a transition phenomenon occurs in which the viscosity of the crude oil (mixed liquid) drops sharply. In particular, when the addition ratio of the surfactant is 1% to 4% by weight and the addition ratio of water is 15% to 40% by weight, the viscosity of the heavy oil (liquid mixture) is rapidly reduced. was confirmed to occur. Furthermore, when the addition ratio of the surfactant is 1.5% by weight or more and 2.5% by weight or less, the viscosity of the heavy oil (mixed liquid) increases more rapidly when the addition ratio of water is about 20% by weight or more and 30% by weight or less. It was confirmed that a declining transition phenomenon occurred. That is, by setting the addition ratio of water and surfactant in such a manner, the transition phenomenon in which the viscosity of the heavy oil (mixed liquid) is rapidly reduced with a small amount of surfactant added can be stably and efficiently generated. I was able to In addition, when the addition ratio of the surfactant was around 2% by weight, even if the addition ratio of water was increased to 20% by weight or more, there was no change in the transition state in which the viscosity of the heavy oil (mixture) decreased. .

In addition, it is presumed that even if the addition ratio of the surfactant is increased to 5% by weight or more, the addition ratio of water does not change significantly. Therefore, sufficient emulsification occurs by setting the addition ratio of the surfactant to 0.5% by weight or more and 5% by weight or less and the addition ratio of water to 10% by weight or more and 45% by weight or less with respect to the heavy oil. The effect can be expected.

Considering environmental protection and influence on fisheries, it is preferable to use the surfactant as little as possible. Therefore, also from this point of view, it is preferable that the addition ratio of the surfactant is 1% by weight or more and 4% by weight or less, and the addition ratio of water is 15% by weight or more and 40% by weight or less. is more preferably 1.5% by weight or more and 2.5% by weight or less, and the addition ratio of water is more preferably about 20% by weight or more and 30% by weight or less.

As described above, according to the heavy oil recovery system and recovery method of the present embodiment, the fluidity is improved by reducing the viscosity of the heavy oil, and the recovery of the heavy oil becomes easier. In particular, when the heavy oil, water, and surfactant are mixed and emulsified, the viscosity of the heavy oil drops rapidly and emulsification can be performed within the range where transition occurs, so the effect of effectively reducing the viscosity is large. .

Therefore, it is possible to expedite the work of recovering heavy oil from tanks of wrecks and the like, which may cause marine pollution, thereby preventing environmental pollution. In addition, since the fluidity of the heavy oil is improved, it is possible to reconsider the recovery system using a conventional recovery pump or the like, and the size of the recovery pipe or the like in the recovery system can be reduced. Along with this, the capacity of the electric motor for driving the pump or the like can be changed to be smaller, and the size and weight of the recovery system can be reduced. As a result, recovery work is also simplified, and in case of emergency, it is possible to respond more quickly, leading to shortening of recovery work time and cost reduction.

The above embodiment can be applied to the recovery of heavy oil and the like stored in a liquid tank (tank) of a ship, but is not limited to this, and can be applied to the refinement and fluidization of various heavy oil. can do. For example, it can be applied to prevent or eliminate clogging in a pipe due to a solid phase (hydrate wax) in a flow line in flow assurance.

10 main body, 10a, 10b flange, 12 liquid supply pipe, 12a mixing tank, 14 injection nozzle, 16 pump, 18 stirrer, 20a, 20b temperature sensor, 22 preheating means, 24 flow meter, 100 recovery system, 102 emulsion unit, 104 recovery pipe, 106 pump, 108 liquid supply pipe, 110 electric wire, 200 recovery vessel, 300 recovery target vessel, 400 heavy oil carrier.

Claims (18)

A recovery method for emulsifying and recovering heavy oil,
10% by weight or more and 45% by weight or less of water and 0.5% by weight or more and 5% by weight or less of a surfactant are added to the heavy oil, and the viscosity is lowered by stirring and emulsifying. A method for recovering heavy oil, characterized by recovering. The method for recovering heavy oil according to claim 1,
A method for recovering heavy oil, wherein the heavy oil whose viscosity has decreased and fluidity has increased is recovered through a pipe by means of a pump. The method for recovering heavy oil according to claim 2,
A method for recovering heavy oil, characterized in that the heavy oil, the water, and the surfactant are also stirred by the pump means. The method for recovering heavy oil according to any one of claims 1 to 3,
The heavy oil recovery method, wherein the heavy oil is a substance having a viscosity of 50 mPa·s or more. The heavy oil recovery method according to any one of claims 1 to 4,
A method for recovering heavy oil, wherein the heavy oil is preheated to reduce the viscosity before adding the water and the surfactant. The heavy oil recovery method according to any one of claims 1 to 5,
A method for recovering heavy oil, wherein the surfactant has low hydrophilicity and high lipophilicity. The heavy oil recovery method according to claim 6,
A method for recovering heavy oil, wherein the numerical value (HLB) indicating the balance between the hydrophilicity and the lipophilicity of the surfactant is less than 20. The method for recovering heavy oil according to any one of claims 1 to 7,
A method for recovering heavy oil, characterized in that the heavy oil is pulverized by spraying the water and the surfactant, and then stirred. The method for recovering heavy oil according to any one of claims 1 to 8,
A method of recovering heavy oil, wherein the recovery is recovery from a heavy oil tank containing the heavy oil in a sunken ship existing under water. A recovery system for emulsifying and recovering heavy oil,
a pipe through which the heavy oil flows;
adding means for adding 10% by weight or more and 45% by weight or less of water and 0.5% by weight or more and 5% by weight or less of a surfactant with respect to the heavy oil;
a stirring means for stirring the heavy oil, the water, and the surfactant;
and pump means for collecting the heavy oil emulsified by stirring with the stirring means. The heavy oil recovery system according to claim 10,
The heavy oil recovery system, wherein the adding means has a high-pressure injection nozzle for injecting the water and the surfactant toward the heavy oil flowing inside the pipe. A heavy oil recovery system according to claim 11,
The adding means has a mixing tank for pre-mixing the water and the surfactant, and the liquid mixture of the water and the surfactant mixed in the mixing tank is supplied to the high-pressure injection nozzle via a high-pressure pump. A heavy oil recovery system, characterized by: The heavy oil recovery system according to any one of claims 10 to 12,
A heavy oil recovery system comprising, as the stirring means, a stirrer having a propeller disposed inside the pipe downstream of the adding means. The heavy oil recovery system according to any one of claims 10 to 13,
The heavy oil recovery system, wherein the pump means also serves as the stirring means. The heavy oil recovery system according to any one of claims 10 to 14,
A heavy oil recovery system comprising preheating means for preheating the heavy oil at the tip of the pipe that sucks the heavy oil. The heavy oil recovery system according to any one of claims 10 to 15,
flow rate detection means for detecting the flow rate of the heavy oil passing through the inside of the pipe;
A heavy oil recovery system comprising control means for controlling the amounts of the water and the surfactant added by the addition means according to the flow rate of the heavy oil detected by the flow rate detection means. . The heavy oil recovery system according to any one of claims 10 to 16,
The piping is attached to a heavy oil tank containing the heavy oil in a submerged wreck,
The addition means, the stirring means, and the pump means are provided at the tip of the pipe on the heavy oil tank side,
A heavy oil recovery system, characterized in that the recovered heavy oil is conveyed to a heavy oil recovery ship facing the water surface and stored therein. A heavy oil recovery system according to claim 17,
A heavy oil recovery system, wherein the heavy oil recovery ship has transfer means for transferring the contained heavy oil to a heavy oil carrier.

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