JP6705112B2 - Demulsification apparatus and demulsification method - Google Patents

Description

The present invention relates to a demulsifying apparatus and a demulsifying method.

In recent years, emulsions in which fine droplets (dispersed phase) are dispersed in a liquid serving as a continuous phase have been used in various fields. For example, emulsions are used as industrial chemicals, cosmetics, food additives, pharmaceutical materials and the like. The basic components of the emulsion are water, oil and surfactant, but the emulsion actually used is a complex multi-component system. Emulsions are generally classified into oil-in-water emulsions (O/W emulsions) whose dispersed phase is an oil phase, and water-in-oil emulsions (W/O emulsions) whose dispersed phase is an aqueous phase.
On the other hand, waste water discharged in the manufacturing process of foods, agricultural chemicals, chemicals, paints, inks, adhesives, etc., cleaning waste water discharged in the cleaning of manufacturing equipment, waste water generated by metal processing using cutting oil, etc. It may be an emulsion. Since emulsions are stable, it is difficult to naturally separate waste water into water and oil, and most of them are incinerated as industrial waste. Therefore, it is desired to reduce the waste liquid treatment cost and reuse the waste liquid by demulsifying the emulsion and separating it into water and oil. In addition, demulsification refers to a process in which a system that is stable as an emulsion is actively destroyed and transferred to a phase separation system.
As the demulsification method, a method of applying centrifugal force/shearing force to the emulsion, a method of applying an electric field to the emulsion (see, for example, Patent Document 1), a method of adding an acidic substance or a basic substance to the emulsion, and a coagulant are used. The method of adding to an emulsion is mentioned.
The method of applying an electric field to the emulsion has the advantages that the emulsion can be continuously demulsified, that no coagulant is required, and that the quality of the separated liquid does not easily deteriorate.

JP, 2014-147913, A

Regarding the demulsification method of applying an electric field to the emulsion as described above, the present inventor has studied in more detail, and is effective for demulsification of a W/O emulsion having a large content of oil, but the content of oil is It was found that it was not very effective in demulsifying small O/W emulsions.
The present invention has been made in view of such circumstances, and provides a demulsifying apparatus and a demulsifying method suitable for demulsifying an O/W emulsion having a low oil content.

The present invention provides a slug flow, a parallel two-phase flow or a merging portion that forms a mixed flow of these flows by merging a flow of an emulsion and a flow of an organic solvent, and an electrode pair having a first electrode and a second electrode. A slender flow path sandwiched between the electrode pair and in which the parallel two-phase flow or the mixed flow flows, and a power supply circuit for applying a voltage to the electrode pair, provide.
The present invention also provides a demulsification method including a step of applying an alternating electric field to a slag flow consisting of an emulsion phase and an organic solvent phase, a parallel two-phase flow or a mixed flow of these flows.
The slag flow is a flow in which the emulsion phase and the organic solvent phase alternately flow in the elongated flow path, and the parallel two-phase flow is a flow in which the emulsion phase and the organic solvent phase flow in the elongated flow path in parallel. The mixed flow is a flow in which the slag flow and the parallel two-phase flow are mixed.

The demulsifier of the present invention is a slug flow that joins a flow of an emulsion and a flow of an organic solvent, a parallel two-phase flow or a merging portion that forms a mixed flow of these flows, the slag flow, and the parallel two-phase flow. Alternatively, since the slender flow path through which the mixed flow flows is provided, the emulsion as the liquid to be treated can be flown together with the organic solvent in the slender flow path as a slag flow, a parallel two-phase flow or a mixed flow.
Since the demulsification apparatus of the present invention includes an electrode pair having a first electrode and a second electrode and a power supply circuit that applies a voltage to the electrode pair, the AC voltage is applied between the electrode pair by the power supply circuit. Therefore, an AC electric field can be generated between the first electrode and the second electrode.
Since the elongated channel is sandwiched by the electrode pair, it is possible to apply an AC electric field to the slug flow, the parallel two-phase flow or the mixed flow consisting of the emulsion phase and the organic solvent phase flowing through the elongated channel by the electrode pair for a long time. it can. This allows the emulsion to be demulsified. This was proved by the experiment conducted by the present inventor.
The mechanism of demulsification is not clear, but it is considered as follows. It is considered that a circulating flow is generated in the emulsion phase in the minute space by the alternating electric field and the oil phase contained in the emulsion phase is united with the organic solvent phase by this circulating flow. Therefore, it is considered that the water phase and the oil phase contained in the emulsion phase are separated and the emulsion is demulsified.

It is a schematic structure figure of the demulsification device of one embodiment of the present invention. It is a schematic sectional drawing of the electric field formation part in dashed line AA of FIG. It is a schematic sectional drawing of the electric field formation part in dashed line BB of FIG. It is a conceptual diagram of the demulsification apparatus of one Embodiment of this invention. (A) is a conceptual diagram of demulsification of an emulsion phase in a slag flow, and (b) is a conceptual diagram of demulsification of an emulsion in a parallel two-phase flow. (A) is a photograph of the liquid collected in the graduated cylinder of the sample that was successfully demulsified, and (b) is a photograph of the liquid collected in the graduated cylinder of the sample that was not successfully demulsified. It is a graph which shows the result of the demulsification experiment 2.

The demulsifier of the present invention includes a slug flow, a two-phase parallel flow or a merging portion that forms a mixed flow of these flows by combining the flow of the emulsion and the flow of the organic solvent, and the first electrode and the second electrode. An electrode pair having the same, an elongated channel sandwiched between the electrode pair and through which the slug flow, the parallel two-phase flow or the mixed flow flows, and a power supply circuit for applying a voltage to the electrode pair. ..
The demulsification method of the present invention is characterized by including a step of applying an AC electric field to a slag flow consisting of an emulsion phase and an organic solvent phase, a parallel two-phase flow or a mixed flow of these flows.

It is preferable that the merging section included in the demulsifier of the present invention is provided so as to merge the flow of the oil-in-water emulsion and the flow of the organic solvent to form a slag flow, a parallel two-phase flow or a mixed flow. As a result, the oil-in-water emulsion can be demulsified by the demulsifying apparatus of the present invention.
The elongated flow path included in the demulsifier of the present invention is preferably formed by an insulating flow path member. As a result, a large electric field can be applied to the slag flow, the parallel two-phase flow, or the mixed flow flowing in the elongated channel, and the emulsion can be efficiently demulsified.

The demulsifier of the present invention preferably comprises a storage tank into which the liquid flowing through the elongated channel flows. As a result, the liquid demulsified by the electric field treatment can be separated into the water layer and the oil layer in the storage tank, and the emulsion can be separated into water and oil for processing.
The demulsifying apparatus of the present invention preferably includes an addition unit that adds an additive to the emulsion. By adding an additive to the emulsion, it becomes possible to modify an emulsion that is difficult to demulsify into an emulsion that is easy to demulsify.

The demulsification method of the present invention preferably includes a step of combining the emulsion flow and the organic solvent flow to form the slag flow, the parallel two-phase flow, or the mixed flow. As a result, a slug flow, a parallel two-phase flow or a mixed flow that is the target of the electric field treatment can be formed.
The demulsification method of the present invention preferably includes a step of applying an alternating electric field to a slag flow, a parallel two-phase flow or a mixed flow composed of an oil-in-water emulsion phase and an organic solvent phase. This allows the oil-in-water emulsion to be demulsified.
The demulsification method of the present invention preferably further comprises a step of causing the slag flow, the parallel two-phase flow or the mixed flow after application of an alternating electric field to flow into a storage tank. As a result, the liquid demulsified by the electric field treatment can be separated into a water layer and an oil layer, and the emulsion can be separated into water and oil for processing.

An embodiment of the present invention will be described below with reference to the drawings. The configurations shown in the drawings and the following description are examples, and the scope of the present invention is not limited to those shown in the drawings and the following description.

1 is a schematic configuration diagram of the demulsifier of the present embodiment, FIG. 2 is a schematic cross-sectional view of an electric field forming portion taken along the broken line AA in FIG. 1, and FIG. It is a schematic sectional drawing of a formation part. FIG. 4 is a conceptual diagram of the demulsifier of the present embodiment, FIG. 5(a) is a conceptual diagram of demulsifying an emulsion phase in a slag flow, and FIG. 5(b) is a conceptual diagram of emulsion in a parallel two-phase flow. It is a conceptual diagram of demulsification.

The demulsifier 30 of the present embodiment includes a merging unit 7 that merges the flow of the emulsion 12 and the flow of the organic solvent 22 to form a slag flow 33, a parallel two-phase flow 34, or a mixed flow of these flows; An electrode pair 4 having an electrode 1 and a second electrode 2, an elongated channel 6 sandwiched between the electrode pair 4 and in which a slug flow 33, a parallel two-phase flow 34 or a mixed flow flows, and a voltage is applied to the electrode pair 4. And a power supply circuit 10.
The demulsification method of the present embodiment is characterized by including a step of applying an AC electric field to the slag flow 33 composed of the emulsion phase 13 and the organic solvent phase 23, the parallel two-phase flow 34, or a mixed flow of these flows.
Hereinafter, the demulsifying apparatus and the demulsifying method of this embodiment will be described.

1. Formation of Slag Flow or Parallel Two-Phase Flow The liquid to be treated for demulsification by the demulsification device 30 and the demulsification method of this embodiment is an emulsion 12. The liquid to be treated may be an oil-in-water emulsion or a water-in-oil emulsion. The oil-in-water emulsion is an emulsion in which an oil phase 32 which is a dispersed phase is dispersed in an aqueous phase 31 which is a continuous phase. The water-in-oil emulsion is an emulsion in which an aqueous phase 31 which is a dispersed phase is dispersed in an oil phase 32 which is a continuous phase.
The emulsion 12 is metal-processed using, for example, waste water discharged in the manufacturing process of foods, agricultural chemicals, chemicals, paints, inks, adhesives, etc., cleaning waste water discharged in the cleaning of manufacturing equipment, cutting oil, etc. For example, generated wastewater. Further, the emulsion 12 may include a water-soluble chloride.

The emulsion 12 is supplied to the merging section 7 at a substantially constant flow rate. As a result, the slug flow 33, the parallel two-phase flow 34, or the mixed flow can be formed at the confluence portion 7. For example, like the demulsifier 30 shown in FIG. 1, the emulsion 12 can be stored in the emulsion tank 14, and the emulsion 12 can be supplied to the merging part 7 by the pump 16a. Moreover, you may supply the emulsion 12 to the confluence|merging part 7 with the syringe pump 17a like the demulsification apparatus 30 shown in FIG.

A filtering unit 15 that allows the emulsion 12 to pass therethrough may be provided before the emulsion 12 is supplied to the merging unit 7. As a result, the solid matter contained in the emulsion 12 can be removed.
The demulsifier 30 of the present embodiment may include an addition unit 25 that adds an additive to the emulsion 12. The emulsion 12 is easily demulsified by adding the additive. The additive is, for example, a water-soluble chloride such as sodium chloride, calcium chloride or lanthanum chloride.

The organic solvent 22 is a solvent that absorbs the oil phase contained in the emulsion 12. The organic solvent 22 is not particularly limited as long as it can dissolve the oil phase contained in the emulsion 12 and is insoluble in water, and examples thereof include p-xylene, toluene and kerosene.
The organic solvent 22 is supplied to the merging section 7 at a substantially constant flow rate. As a result, the slug flow 33, the parallel two-phase flow 34, or the mixed flow can be formed at the confluence portion 7. For example, like the demulsifier 30 shown in FIG. 1, the organic solvent 22 can be stored in the organic solvent tank 24, and the organic solvent 22 can be supplied to the merging part 7 by the pump 16b. Further, as in the demulsifier 30 shown in FIG. 4, the organic solvent 22 may be supplied to the joining section 7 by the syringe pump 17b.

The merging portion 7 is a portion that joins the flow of the emulsion 12 and the flow of the organic solvent 22 to form a slag flow 33, a parallel two-phase flow 34, or a mixed flow. The confluence part 7 can be provided so that the slag flow 33 flows through at least a part of the elongated flow path 6.
In the confluence part 7, an emulsion flow path 36 in which the emulsion 12 flows into the confluence part 7, an organic solvent flow path 37 in which the organic solvent 22 flows into the confluence part 7, a slag flow 33 formed in the confluence part 7, and a parallel two-way structure. The elongated flow path 6 through which the phase flow 34 or the mixed flow flows is connected.
This elongated channel 6 is sandwiched between the first electrode 1 and the second electrode 2 and an AC electric field is applied to the slug flow 33, the parallel two-phase flow 34 or the mixed flow, which will be described later.

The slag flow 33 is a flow in which the emulsion phase 13 and the organic solvent phase 23 flow alternately in the elongated flow path 6. When the slag flow 33 is formed by the confluence portion 7, the emulsion phase 13 can be confined between the two adjacent organic solvent phases 23 in the elongated channel 6. Further, many interfaces between the emulsion phase 13 and the organic solvent phase 23 can be formed. For example, as shown in FIG. 4 and FIG. 5A, the slag flow can be passed through the flow path 6 in the flow path member 8. In the elongated channel 6, the flow form may change from the slug flow to the parallel two-phase flow. In this case, the flow form is a mixed flow in which the slag flow 33 and the parallel two-phase flow 34 are mixed.

The parallel two-phase flow 34 is a flow in which the emulsion phase 13 and the organic solvent phase 23 flow in parallel in the elongated channel 6. By forming the parallel two-phase flow 34 by the merging portion 7, the interface between the emulsion phase 13 and the organic solvent phase 23 can be widened. For example, as shown in FIG. 5B, the parallel two-phase flow 34 can be passed through the flow path 6 in the flow path member 8. In the elongated channel 6, the flow form may change from parallel two-phase flow to slug flow. In this case, the flow form is a mixed flow in which the slag flow 33 and the parallel two-phase flow 34 are mixed.

The confluence part 7 can have a T-shaped channel or a Y-shaped channel consisting of two inflow channels and one outflow channel. Moreover, the confluence|merging part 7 can have a bead inserted in the outflow channel. Thereby, the slag flow can be easily formed.
The confluence part 7 may be, for example, a T-shaped tube or a Y-shaped tube. In this case, the slug flow 33, the parallel two-phase flow 34, or the mixed flow can be made to flow in the elongated flow path 6. In addition, when the flow form of the elongated channel 6 is a mixed flow, the flow form may change from the slag flow 33 to the parallel two-phase flow 34, or the flow form may change from the parallel two-phase flow 34 to the slag flow 33. ..
Further, the confluence part 7 may be a bead-insertion type microreactor. In this case, the flow form of the elongated channel 6 can be a slug flow 33 of about 1 mm.

2. Formation of Electric Field The demulsifier 30 of this embodiment includes an electrode pair 4 having a first electrode 1 and a second electrode 2, and a power supply circuit 10 for applying a voltage to the electrode pair 4. The first electrode 1 and the second electrode 2 are provided so that an alternating electric field is generated therebetween. For example, the plate-shaped first electrode 1 and the plate-shaped second electrode 2 can be arranged so as to overlap with each other with the flow path member 8 interposed therebetween. Further, the first electrode 1 and the second electrode 2 can be arranged in parallel. Moreover, the first electrode 1 or the second electrode 2 can be formed in a flat plate shape. In such a configuration, when an AC voltage is applied between the first electrode 1 and the second electrode 2 by the power supply circuit 10, an AC electric field can be generated between the first electrode 1 and the second electrode 2. ..
Further, the first electrode 1 or the second electrode 2 may be a rectangular metal plate or a square metal plate. The material of the first electrode 1 or the material of the second electrode 2 is not particularly limited as long as it is a conductive material, and examples thereof include metallic copper, metallic silver, metallic aluminum and the like.
Further, the first electrode 1 or the second electrode 2 may have an electrode terminal. As a result, the power supply circuit 10 can be connected via the electrode terminals.

The power supply circuit 10 is not particularly limited as long as it can apply an AC voltage between the first electrode 1 and the second electrode 2, but can include, for example, a high voltage generator 18. Thereby, a strong electric field can be generated between the first electrode 1 and the second electrode 2. Further, the power supply circuit 10 may include both the high voltage generator 18 and the function generator 19. As a result, an AC voltage having an arbitrary frequency and waveform can be applied between the first electrode 1 and the second electrode 2.
Further, the power supply circuit 10 applies a voltage to the electrode pair 4 so that an electric field of 10×10 ⁴ V/m or more and 500×10 ⁴ V/m or less is generated between the first electrode 1 and the second electrode 2. be able to. Further, the power supply circuit 10 can apply an alternating voltage of 10 Hz or more and 500 Hz or less between the first electrode 1 and the second electrode 2. When an AC voltage is applied between the first electrode 1 and the second electrode 2 by the power supply circuit 10, the waveform of the AC voltage may be a sine wave, a rectangular wave, or a triangular wave. May be.

The electric field strength (V/m) of the electric field generated between the first electrode 1 and the second electrode 2 is the same as the voltage applied between the first electrode 1 and the second electrode 2 when the voltage applied between the first electrode 1 and the second electrode 2 is the same. It can be represented by a value divided by the distance D from the electrode 2. The distance D between the first electrode 1 and the second electrode 2 can be, for example, 0.2 mm or more and 40 mm or less. As a result, an electric field having a high electric field strength can be generated between the first electrode 1 and the second electrode 2 with a relatively low applied voltage.
The distance D between the first electrode 1 and the second electrode 2 can be made constant by providing a spacer 26 having a constant thickness between the first electrode 1 and the second electrode 2. Further, the distance D between the first electrode 1 and the second electrode 2 can be made constant by making the thickness of the flow path member 8 constant.
The material of the spacer 26 may be an insulating material, for example, plastic having good electrical insulation. The material of the spacer 26 can be, for example, acetal resin.

3. The elongated channel 6 in which the slag flow 33, the parallel two-phase flow 34, or the mixed flow formed in the demulsification merging section 7 by the electric field flows is sandwiched between the first electrode 1 and the second electrode 2. Therefore, an alternating electric field can be applied to the slug flow 33, the parallel two-phase flow 34, or the mixed flow composed of the emulsion phase 13 and the organic solvent phase 23 flowing in the elongated channel 6 by the electrode pair 4 for a long time. As a result, the emulsion 12 can be demulsified. This was proved by the experiment conducted by the present inventor.
The mechanism of demulsification is not clear, but it is considered as follows. It is considered that a circulating flow is generated in the emulsion phase 13 in the minute space by the alternating electric field, and the oil phase contained in the emulsion phase 13 is united with the organic solvent phase by this circulating flow. Therefore, it is considered that the water phase 31 and the oil phase 32 contained in the emulsion phase 13 are separated and the emulsion is demulsified.
For example, as shown in FIGS. 5A and 5B, the oil phase 32 contained in the emulsion phase 13 is considered to be absorbed by the organic solvent phase 23 under an AC electric field.

The flow path member 8 forming the elongated flow path 6 may be in the form of a tube having the flow path 6 inside, or may be in the form of a plate having the elongated flow path 6 inside. Further, at least a part of the flow path member 8 is sandwiched between the first electrode 1 and the second electrode 2. As a result, an AC electric field between the electrode pair 4 can be applied to the slug flow 33, the parallel two-phase flow 34 or the mixed flow in the elongated channel 6, and the slug flow 33, the parallel two-phase flow 34 or the mixed flow can be applied to the electric field. Can be processed. Further, this makes it possible to continuously subject the slag flow 33, the parallel two-phase flow 34 or the mixed flow in the flow path 6 to electric field treatment. Further, the first electrode 1, the second electrode 2, and the flow path member 8 may form an electric field forming portion 11.

The elongated channel 6 may be provided in a linear shape, may be provided with a bent portion, or may be provided so as to meander. For example, as shown in FIGS. 1 to 3, the flow path member 8 has a tubular shape, and the flow path 6 can be provided so as to meander. By providing the flow path 6 in a meandering manner, it is possible to prevent the demulsification device 30 from increasing in size even if the distance of the flow path 6 is increased.
One end of the flow path member 8 (elongate flow path 6) can be connected to the merging portion 7, and the other end can be connected to the storage tank 21. As a result, the slag flow 33, the parallel two-phase flow 34, or the mixed flow formed at the confluence portion 7 can be flowed through the elongated channel 6 to be subjected to the electric field treatment, and the liquid after the electric field treatment can be caused to flow into the storage tank 21. it can.
The length of the elongated channel 6 between the electrode pair 4 can be, for example, 10 cm or more and 50 m or less, and preferably 10 cm or more and 10 m or less. In addition, when a part of the elongated channel 6 protrudes from the electrode pair 4, the total length of the portion sandwiched by the electrode pair 4 of the elongated channel 6 can be 10 cm or more and 50 m or less, It is preferably 10 cm or more and 10 m or less. Further, by changing the length of the elongated channel 6, the flow rate such as the slag flow, or both, the time for electric field treatment of the slug flow 33 or the parallel two-phase flow 34 can be changed.
When the flow path member 8 is a flexible tube, the spacer 26 may be provided so that the position where the flow path member 8 is arranged is determined, as shown in FIGS. Thereby, the flow path member 8 can be stably arranged between the first electrode 1 and the second electrode 2. In the electric field forming unit 11 shown in FIGS. 1 to 3, a spacer 26 is provided between the first electrode 1 and the second electrode 2 with a space in which the flow path member 8 is arranged in a meandering manner. Has been.

The elongated channel 6 may be provided on the same plane between the electrode pairs 4. As a result, even when the flow path 6 is long, the distance between the first electrode 1 and the second electrode 2 can be narrowed, and a strong electric field can be generated between the first electrode 1 and the second electrode 2. Can be generated. The elongated channel 6 can be provided on a plane including the broken line B-B like the electric field forming unit 11 shown in FIGS.
Further, the flow path member 8 can be provided so as to contact both the first electrode 1 and the second electrode 2. As a result, the distance between the first electrode 1 and the second electrode 2 can be narrowed, and a large electric field can be applied to the slag flow 33, the parallel two-phase flow 34 or the mixed flow flowing in the flow path 6.

The shape of the cross section of the elongated flow path 6 included in the flow path member 8 is not particularly limited, but may be, for example, a circular shape or a square shape. Further, the elongated channel 6 can be provided so that the shortest distance d between the facing inner walls is 0.1 mm or more and 30 mm or less. When the cross section of the elongated channel 6 is circular, the diameter d of the elongated channel 6 can be 0.1 mm or more and 30 mm or less. Further, when the flow paths 6 are provided on the same plane between the electrode pairs 4, the flow is made so that the distance d between the facing inner walls of the flow paths 6 in the direction perpendicular to this plane is 0.1 mm or more and 30 mm or less. A channel 6 can be provided. For example, the flow path member 8 may be a fluororubber tube having an inner diameter of 1 mm and an outer diameter of 3 mm.
With such a configuration, a strong AC electric field can be applied to the slag flow 33, the parallel two-phase flow 34, or the mixed flow flowing in the minute space.

The material of the flow path member 8 can be an insulating material. As a result, even if the distance between the electrode pairs 4 is narrowed, it is possible to prevent the leak current from flowing between the electrode pairs 4. Further, the distance between the first electrode 1 and the second electrode 2 can be narrowed, and a large AC electric field can be applied to the slug flow 33, the parallel two-phase flow 34 or the mixed flow of the flow path 6.
Further, the material of the flow path member 8 can be a material having corrosion resistance to the emulsion 12 and the organic solvent 22. The material of the flow path member 8 is, for example, glass, silicon resin, fluororesin or the like.

4. Oil-Water Separation The demulsification device 30 of the present embodiment can include a storage tank 21 into which the liquid flowing through the elongated channel 6 flows. The slag flow 33, the parallel two-phase flow 34, or the mixed flow subjected to the electric field treatment by the electrode pair 4 flows into the storage tank 21.
Since the emulsion phase 13 contained in the slag flow 33, the parallel two-phase flow 34 or the mixed flow has been demulsified by the electric field treatment, the storage tank 21 is substantially oil-soluble with the organic solvent phase in which the oil phase of the emulsion is dissolved. A slug flow 33, a parallel two-phase flow 34 or a mixed flow with a phase-free aqueous phase flows in. By storing the inflowing liquid in the storage tank 21, the water is separated into the lower layer and the organic solvent into the upper layer due to the difference in specific gravity between the water and the organic solvent. Therefore, it becomes possible to treat water and the organic solvent separately. Further, the separated organic solvent can be reused as the organic solvent 22 for demulsifying the emulsion 22. The surfactant contained in the emulsion 22 is separated as the surfactant-containing substance 29 between the upper organic solvent layer and the lower aqueous layer.

Demulsification experiment 1
A demulsification experiment was conducted using the demulsifier 30 shown in FIGS. However, to supply the emulsion 12 and the organic solvent 22 to the merging portion 7, syringe pumps 17a and 17b as shown in FIG. 4 were used.
The confluence section 7 was a bead-inserted microreactor or a Y-tube. When a bead-insertion type microreactor is used for the confluence part 7, the slender flow path 6 has a flow form of about 1 mm.
When a Y-shaped tube is used for the confluence part 7, the flow form of the elongated channel 6 becomes a slug flow, a parallel two-phase flow or a mixed flow. When the flow form is a mixed flow, the flow form may change from a slug flow to a parallel two-phase flow or a parallel two-phase flow to a slug flow. When the flow form is a slag flow, the length of each phase of the slag flow is longer than when a bead-insertion type microreactor is used.

In the electric field forming unit 11, a copper plate of 100 mm×100 mm is used for each of the first electrode 1 and the second electrode 2, a spacer 26 made of acetal resin is provided between the first electrode 1 and the second electrode 2, and a flow path member is provided. A space was provided between the first electrode 1 and the second electrode 2 so that 8 were arranged in a meandering manner. The distance between the first electrode 1 and the second electrode 2 was 3 mm. In addition, a cover made of acetal resin is provided so as to sandwich the first electrode 1 and the second electrode 2 in order to suppress a leak current and improve safety. A tube made of fluororesin (outer diameter 3 mm, inner diameter 1 mm) was used as the flow path member 8, and the flow path member 8 was placed in the space formed by the spacer 26. The length of the tube located between the first electrode 1 and the second electrode 2 is about 760 mm. Further, one end of the flow path member 8 was connected to the merging portion 7, and the other end of the flow path member 8 was arranged in the graduated cylinder which is the storage tank 21.

An aqueous phase and an oil phase were mixed at a volume ratio of 10:1, a predetermined amount of a surfactant was added, and the mixture was stirred at 24000 rpm for 60 seconds using a homogenizer to prepare emulsions of Samples 1 to 24 shown in Table 1. (Oil content of emulsion: about 9%). Pure water, an aqueous solution of NaCl, an aqueous solution of CaCl ₂ or an aqueous solution of LaCl ₃ was used for the aqueous phase. The ionic strength of each aqueous solution was 0.27 mol·L ⁻¹ . For the oil phase, p-xylene or toluene was used. As the surfactant, sorbitan monooleate (Span80), polyoxyethylene sorbitan monolaurate (Tween20) or sodium linear alkylbenzene sulfonate (LAS) was used. The prepared emulsion is considered to be an oil-in-water emulsion.

The prepared emulsion was put in the syringe pump 17a as shown in FIG. 4, and the organic solvent shown in Table 1 was put in the syringe pump 17b. The same solvent as the oil phase of the emulsion was used as the organic solvent.
The emulsion pump and the organic solvent were mixed with the syringe pumps 17a and 17b in a state where an AC voltage having a frequency of 100 Hz was applied between the first and second electrodes so that the electric field strength between the first and second electrodes was 1000 kV·m ^−1. The slag flow, the parallel two-phase flow, or the mixed flow formed in the merging part 7 was supplied to the merging part 7 at a ratio of 50:50, and was made to flow in the elongated channel 6 between the first and second electrodes. Then, after applying an AC electric field to the slag flow, the parallel two-phase flow or the mixed flow flowing through the elongated channel 6, the slug flow, the parallel two-phase flow or the mixed flow was poured into the graduated cylinder. The liquid collected in the graduated cylinder was naturally separated, and the success or failure of demulsification was visually judged. In addition, the supply flow rates of the emulsion and the organic solvent to the merging section 7 were adjusted so that an AC electric field was applied for about 215 seconds while the slag flow, the parallel two-phase flow or the mixed flow flowed through the elongated channel.

Table 1 shows the success or failure of the demulsification in the demulsification experiment. In the demulsification experiment, those marked with ◯ in Table 1 were judged to be successful in demulsification, while those marked with x in Table 1 were judged to be unsuccessful in demulsification. The experiment indicated by the horizontal line was not performed. Further, FIG. 6(a) is a photograph of the liquid collected in the graduated cylinder of the sample 3 that was successfully demulsified (using a bead-insertion type microreactor for the confluence part 7), and FIG. 6(b) is for demulsification. It is a photograph of the liquid collected in the graduated cylinder of the sample 10 that failed (using a bead-insertion type microreactor in the confluence part 7).
In the sample successfully demulsified, as shown in the photograph of FIG. 6A, the lower layer of transparent water and the upper layer of transparent p-xylene were separated with the surfactant-containing substance sandwiched therebetween. In the sample in which the demulsification failed, as shown in the photograph shown in FIG. 6( b ), the emulsion became cloudy in the lower layer and transparent p-xylene in the upper layer.

In the samples using p-xylene for the organic solvent and the oil phase of the emulsion, Samples 3, 7, and 11 succeeded in demulsification. In these samples, an aqueous solution of CaCl ₂ is used for the water phase.
In Samples 3, 7, and 11 that succeeded in demulsification, the demulsification was successful in both cases where the bead-inserted microreactor was used in the confluence part 7 and the case where a Y-shaped tube was used. On the other hand, in Samples 1, 2, 4 to 6, 8 to 10 and 12 in which the demulsification failed, the demulsification failed even when the bead insertion type microreactor was used in the confluence part 7 or the Y-shaped tube was used. did. Therefore, it is considered that the success or failure of demulsification does not depend on the flow form.
Samples using toluene as the oil phase of the organic solvent and emulsion succeeded in demulsification in Samples 14, 15, 16, 20, and 24. In Samples 14, 15 and 16, Span 80 is used as a surfactant, and in Samples 20 and 24, an aqueous LaCl ₃ solution is used as an aqueous phase.
Therefore, according to the results of Table 1, depending on the type of emulsion and the type of organic solvent, it may or may not be able to be demulsified. It can be seen that applying an alternating electric field while flowing is effective for demulsification of the emulsion.
Further, from the results shown in Table 1, it is considered that the emulsion can be demulsified by adding an additive to the emulsion and selecting an appropriate organic solvent.

Demulsification experiment 2 (comparative example)
A demulsification experiment was conducted in which an emulsion was flowed through a narrow channel and an alternating electric field was applied without forming a slag flow, a parallel two-phase flow or a mixed flow. In this experiment, the emulsion was directly supplied from the syringe pump to the elongated channel 6 without using the merging portion 7, and an AC electric field was applied to the emulsion. Pure water was used as the water phase of the emulsion, p-xylene was used as the oil phase, and Span 80 was used as the surfactant. Further, demulsification experiments were carried out on four types of emulsions having different oil contents. Other conditions were the same as those in Demulsification Experiment 1.
The experimental results are shown in FIG. FIG. 7 is a graph showing the relationship between the oil content of the emulsion used in the experiment and the demulsification rate. The demulsification rate (%) was calculated using the formula (volume of oil phase demulsified by electric field application (ml))÷(total volume of oil phase in emulsion used in experiment (ml))×100. ..
It was found that when the oil content was more than 20 vol%, the emulsion could be demulsified with a high demulsification rate, but when the oil content was 17 vol% or less, the emulsion could not be demulsified.

On the other hand, in the demulsification experiment 1 in which an alternating electric field was applied to the slag flow, the parallel two-phase flow or the mixed flow, the emulsion having an oil content of about 9% could be demulsified. Therefore, it was found that the demulsification method in which an alternating electric field is applied to a slag flow, a parallel two-phase flow or a mixed flow is effective for demulsification of an emulsion having a low oil content.

1: 1st electrode 2: 2nd electrode 4: Electrode pair 6: Elongate flow path 7: Confluence part 8: Flow path member 10: Power supply circuit 11: Electric field formation part 12: Emulsion 13: Emulsion phase 14: Emulsion tank 15: Filtration part 16a, 16b: Pump 17a, 17b: Syringe pump 18: High voltage generator 19: Function generator 20: Electric wire 21: Storage tank 22: Organic solvent 23: Organic solvent phase 24: Organic solvent tank 25: Addition part 26: Spacer 27: Water phase 28: Organic solvent phase 29: Surfactant-containing material 30: Demulsifier 31: Water phase 32: Oil phase 33: Slag flow 34: Parallel two-phase flow 36: Emulsion flow path 37: Organic solvent flow Road

Claims (8)

A slug flow, a parallel two-phase flow or a merging portion that forms a mixed flow of these flows by combining the flow of the emulsion and the flow of the organic solvent, an electrode pair having a first electrode and a second electrode, and the electrode pair. An elongated flow path sandwiched between the slug flow, the parallel two-phase flow or the mixed flow, and a power supply circuit for applying a voltage to the electrode pair ,
The length of the portion of the elongated channel sandwiched by the electrode pair or the total thereof is 10 cm or more and 50 m or less,
The elongated channel is provided such that the shortest distance d between the opposing inner walls is 0.1 mm or more and 30 mm or less,
The combination of the emulsion and the organic solvent, the aqueous phase of the emulsion is a CaCl ₂ aqueous solution, the oil phase of the emulsion is p-xylene and the organic solvent is p-xylene, or the aqueous phase of the emulsion is LaCl ₃ is an aqueous solution and is the oil phase is toluene demulsification apparatus wherein the organic solvent is characterized in toluene der Rukoto. The demulsifier according to claim 1, wherein the emulsion is an oil-in-water emulsion. The demulsifier according to claim 1 or 2, wherein the elongated channel is formed of an insulating channel member. The demulsification device according to any one of claims 1 to 3, further comprising a storage tank into which the liquid flowing through the elongated channel flows. The demulsifier according to any one of claims 1 to 4, further comprising an addition unit that adds an additive to the emulsion. A demulsification method for demulsifying an emulsion using the demulsification device according to claim 1.
A demulsification method comprising a step of applying an alternating electric field to a slag flow consisting of an emulsion phase and an organic solvent phase, a parallel two-phase flow or a mixed flow of these flows. Further comprising the step of combining the flow of emulsion and the flow of organic solvent to form the slag flow, the parallel two-phase flow or the mixed flow,
The demulsification method according to claim 6, wherein the emulsion is an oil-in-water emulsion. The demulsification method according to claim 6 or 7, further comprising the step of causing the slag flow, the parallel two-phase flow, or the mixed flow after application of an alternating electric field to flow into a storage tank.