COMPONENT SEPARATION SYSTEM

Abstract

A component separation system, comprising: a first separation unit configured to: add a component C to a single-phase mixed component αβ containing a component A and a component B; and separate a mixed component αβγ containing the component A, the component B, and the component C at a temperature T1 into a separated component αγ containing the component A and the component C as a main component, and a separated component β containing the component B as a main component;and a second separation unit configured to change a temperature of the separated component αγ to a temperature T2 for separating the separated component αγ into a separated component α containing component A as a main component and a separated component γ containing component C as a main component, in which component C has a miscible behavior with respect to component A at temperature T1 of the mixed component αβγ, a separation behavior with respect to component B at temperature T1 of the mixed component αβγ, and a separation behavior with respect to component A at temperature T2 of the separated component αγ.;

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a component separation system. BACKGROUND

[0002] In recent years, a demand for reuse to reduce environmental impact has emerged, and various techniques for separating components have been studied.

[0003] For example, Patent Document 1 discloses that "A method for purifying a reclaimed polypropylene is disclosed. In one embodiment, the method involves obtaining reclaimed polypropylene, contacting the reclaimed polypropylene with a first liquid solvent to produce an extracted reclaimed polypropylene; then dissolving the extracted reclaimed polypropylene in a solvent to produce a first solution containing polypropylene. The first solution is allowed to settle and then filtered. A purer polypropylene is separated from the resulting solution."

[0004] In addition, Patent Document 2 discloses a “method for reducing a volume of expanded polystyrene, comprising: dissolving expanded polystyrene in a dissolving solvent selected from the group consisting of glycol ether acetate compounds, glycol ether compounds, acetylacetone, diethyl carbonate, and ethyl orthoformate.” Patent Document 1: Japanese National Phase Publication (JP-A) No. 2021-526575 Patent Document 2: Japanese Patent Application Laid-Open (JP-A) No. H11-80418 SUMMARY OF THE INVENTIONTechnical Problem

[0005] In Patent Document 1, high-purity recycled polypropylene is obtained by dissolving recycled polypropylene in a low-boiling-point solvent under high pressure and separating the polypropylene from impurities. By reducing the pressure after removing impurities, the low-boiling-point solvent can be easily separated from the polypropylene.

[0006] However, the process of Patent Document 1 requires processing under high pressure conditions, resulting in increased equipment costs. Furthermore, since the solvent is easily evaporated after use under normal pressure, recovery or reuse of the solvent becomes difficult. To reduce recycling costs, there is a need for a process that can be carried out under normal pressure and can efficiently recover and reuse the solvent.

[0007] On the other hand, in Patent Document 2, the volume of polystyrene can be reduced by dissolving it in a good solvent, and the polystyrene can be reused by reprecipitating it with a poor solvent. Furthermore, in Patent Document 2, a mixed solvent remaining after reprecipitation is separated by distillation and reused.

[0008] However, although the distillation method used in Patent Document 2 is often used as a component separation method in a mixed solvent, the heating costs are known to be high. A low-cost method for separating the mixed solvent after reprecipitation is needed.

[0009] Therefore, it is an object of the disclosure to provide a component separation system capable of performing component separation with energy saving under normal pressure without using distillation. Solution to the problem

[0010] Means for solving the problems described above include the following embodiments. <1> Component separation system, with: a first separation unit configured to: add a component C to a single-phase mixed component αβ containing a component A and a component B; and separate a mixed component αβγ containing component A, component B, and component C at a temperature T1 into a separated component αγ containing component A and component C as a main component, and a separated component β containing component B as a main component; and a second separation unit configured to change a temperature of the separated component α to a temperature T2 for separating the separated component αγ into a separated component α containing component A as a main component and a separated component γ containing component C as a main component, in which component C has a miscible behavior with respect to component A at the temperature T1 of the mixed component αβγ, a separation behavior with respect to component B at the temperature T1 of the mixed component αβγ and exhibits a separation behavior with respect to component A at the temperature T2 of the separated component αγ. <2> Component separation system according to <1> , wherein the first separation unit is a separation unit configured to: add the component C as an extractant for the component A to the mixed component αβ in which the component A in a liquid state and the component B in a liquid state are uniformly mixed, to extract the component A with the component C; and carry out liquid-liquid separation of the separated component αγ and the separated component β. <3> Component separation system according to <2> , in which the mixed component αβ is a mixed system after reprecipitation of a solid substance and is a mixed component in which component A as a poor solvent for the solid substance and component B as a good solvent for the solid substance are uniformly mixed. <4> Component separation system according to <3> , in which: the solid substance is a styrene resin, component A is an alcohol, component B is a terpene, and component C is ethylene carbonate. <5> Component separation system according to <1> , wherein the first separation unit is a separation unit configured to: add component C in a liquid state as a poor solvent for component B to the mixed component αβ in which component B in a solid state is dissolved in component A in a liquid state which is a good solvent for component B, to reprecipitate component B; and carry out liquid-liquid separation of the separated component αγ and the separated component β. <6> Component separation system according to <5> , in which: component A is an aromatic hydrocarbon, component B is a polyolefin resin, and component C is ethylene carbonate. <7> Component separation system according to one of <2> until <6> , in which the temperature T2 is set based on a proportion of component A or component C in the separated component αγ. <8> Component separation system according to one of <2> until <6> , in which the temperature T2 is set based on a composition of component A or component C in the separated component αγ. <9> Component separation system according to <8> , in which: component A is at least one selected from the group consisting of aromatic hydrocarbons and alcohols, component B is a polyolefin resin, and component C contains ethylene carbonate. <10> Component separation system according to <9> in which component A is two aromatic hydrocarbons or two alcohols. <11> Component separation system according to <9> or <10> wherein component C is ethylene carbonate and at least one selected from the group consisting of cyclic carbonates other than ethylene carbonate and polyhydric alcohols. Advantageous effects of the invention

[0011] According to the disclosure, a component separation system capable of performing energy-saving component separation under normal pressure without using distillation can be provided. SHORT DESCRIPTION OF DRAWINGS Fig. 1 is a block diagram illustrating an example of a component separation system of the disclosure. Fig. Figure 2 shows miscibility and phase separation behavior diagrams in a two-component system composition. Fig. 3 is a block diagram illustrating an example of a first separation unit according to a first embodiment of the disclosure. Fig. 4 is a block diagram illustrating another example of the first separation unit according to the first embodiment of the disclosure. Fig. 5 is a block diagram illustrating an example of a first separation unit according to a second embodiment of the disclosure. Fig. 6 is a block diagram illustrating another example of the first separation unit according to the second embodiment of the disclosure. Fig. 7 is a block diagram illustrating an example of a second separation unit according to the embodiment of the disclosure. Fig. 8 is a block diagram illustrating another example of the second separation unit according to the embodiment of the disclosure. Fig. 9 is a block diagram illustrating an example of a solid substance purification system according to the first embodiment of the disclosure. Fig. 10 is a block diagram illustrating an example of a solid substance purification system according to the second embodiment of the disclosure. Fig. Figure 11 is a table showing solubility of a polystyrene resin in a mixed ethanol-limonene solvent. Fig. Figure 12 is a graph showing an energy consumption calculation result of the component separation system. Fig. 12(A) is a graph showing a calculation result of a component separation system of Example 1, and Fig. Figure 12(B) is a graph showing a result of the component separation system according to a conventional distillation process. Fig. Figure 13 is a liquid-liquid equilibrium diagram of an ethylene carbonate-xylene system. Fig. Figure 14 is a table showing solubility of a polypropylene resin in a mixed ethylene carbonate-xylene solvent. Fig. Figure 15 is a graph showing an energy consumption calculation result of the component separation system. Fig. 15(A) is a graph showing a calculation result of a component separation system of Example 2, and Fig. Figure 15(B) is a graph showing a result of the component separation system according to a conventional distillation method. Fig. Figure 16 is a table showing solubility of a polyethylene resin in an ethylene carbonate-xylene mixed solvent. Fig. Figure 17 is a graph showing an energy consumption calculation result of the component separation system. Fig. 17(A) is a graph showing a calculation result of a component separation system of Example 3, and Fig. Figure 17(B) is a graph showing a result of the component separation system according to a conventional distillation process. Fig. Figure 18 is a graph showing a phase change temperature of a (toluene + xylene)-ethylene carbonate system. Fig. Figure 19 is a graph showing a phase change temperature of an (ethanol + 1-propanol)-ethylene carbonate system. Fig. Figure 20 is a graph showing a phase change temperature of a xylene (ethylene carbonate + propylene carbonate) system. Fig. Figure 21 is a graph showing a phase change temperature of a p-cymene (ethylene carbonate + propylene carbonate) system. Fig. Figure 22 is a graph showing a phase change temperature of a xylene (ethylene carbonate + ethylene glycol) system. Fig. Figure 23 is a graph showing the energy consumption calculation result of the component separation system. Fig. 23(a) is a graph showing the calculation result of the component separation system of Example 2, and Fig. Figure 23(b) is a graph showing the result of a component separation system of Example 4. DESCRIPTION OF EMBODIMENTS

[0012] Embodiments of the disclosure are described below. These descriptions and examples represent embodiments and do not limit the scope of the invention.

[0013] In the numerical ranges described in stages in this specification, the upper limit or lower limit specified in a numerical range may be replaced by the upper limit or lower limit of another numerical range described in stages. Furthermore, in the numerical range specified in this specification, the upper limit or lower limit of a numerical range may be replaced by a value shown in examples.

[0014] In this specification, each component may contain a plurality of corresponding substances.

[0015] In addition, when reference is made to the amount of each component in the composition, if there is a plurality of substances corresponding to each component in the composition, it means the total amount of the plurality of substances present in the composition, unless otherwise stated.

[0016] In addition, “normal temperature” means 25°C, and “normal pressure” means 1 atm. <Komponentenseparationssystem (oder Komponentenseparationsverfahren)>

[0017] As in Fig. 1, a component separation method (or a component separation method, the same applies hereinafter) according to the present embodiment includes: a first separation unit (or a first separation process) designed to: adding a component C to a single-phase mixed component αβ containing a component A and a component B; and separating a mixed component αβγ containing component A, component B and component C at a temperature T1 into a separated component αγ containing component A and component C as a main component and a separated component β containing component B as a main component; and a second separation unit (second separation unit) configured to change the temperature of the separated component αγ to a temperature T2 for separating the separated component αγ into a separated component α containing the component A as a main component and a separated component γ containing the component C as a main component.

[0018] As in Fig. 1, the separated component γ can be reused as the component C in the first separation unit (or the first separation process).

[0019] Furthermore, component C has a miscible behavior with respect to component A at the temperature T1 of the mixed component αβγ, has a separation behavior with respect to component B (in particular, in a case that component B is a liquid, component B is phase-separating, or in a case that component B is a solid, component B is insoluble) at the temperature T1 of the mixed component αβγ, and has a separation behavior with respect to component A at the temperature T2 of the separated component αγ.

[0020] In other words, component A exhibits a miscible behavior with respect to component C at temperature T1 of the mixed component αβγ and exhibits a separation behavior with respect to component C at temperature T2 of the separated component αγ.

[0021] On the other hand, component B exhibits a separation behavior with respect to component C at the temperature T1 of the mixed component αβγ.

[0022] Here, as in Fig. 2, the miscible behavior and the phase separation behavior in the composition of the two-component system are classified into behaviors such as (i) a case that an upper critical solution temperature (UCST)-like behavior is observed, (ii) a case that a lower critical solution temperature (LCST)-like behavior is observed, and (iii) a case that a critical temperature is not observed.

[0023] The behavior of the composition of the two-component system with component A and component C corresponds to the behavior of (i) or (ii), and the behavior of the composition of the two-component system with component B and component C corresponds to the behavior of (iii).

[0024] As described above, in the component separation system according to the present embodiment, by using component C having separation behavior for component B and temperature-dependent separation behavior for component A, component B can be separated from the mixed component αβ under normal pressure, and component A can be separated from the separated component αγ. That is, by utilizing the equilibrium shift of component A and component C, a series of separation operations can be carried out under normal pressure, and each component can be separated without distillation.

[0025] Therefore, the component separation system according to the present embodiment can perform energy-saving component separation under normal pressure without using distillation.

[0026] Here, the “mixed component αγ containing component A and component C as a main component” indicates a mixed system containing component A and component C in an amount of 51 mass% or more with respect to the total separated component αγ.

[0027] The “component α containing component A as a main component” indicates a component containing component A in an amount of 51 mass% or more with respect to the total component α.

[0028] The “separated component β containing component B as a main component” indicates a separated component containing component B in an amount of 51 mass% or more with respect to the total separated component β.

[0029] The “separated component γ containing component C as a main component” indicates a separated component containing component C in an amount of 51 mass% or more with respect to the total separated component γ.

[0030] That is, “component C exhibits miscible behavior with respect to component A at temperature T1 of the mixed component αβγ and exhibits separation behavior with respect to component B at temperature T1 of the mixed component αβγ” means that the mixed component αβγ is separated into a separated component αγ in which a total proportion of component A and component C to the total separated component αγ is 51 mass% or more, and a separated component γ in which a proportion of component B to the total separated component β is 51 mass% or more.

[0031] Also, “component C exhibits separation behavior with respect to component A at temperature T2 of the separated component αγ” means that the separated component αγ is separated into a separated component α in which the proportion of component A in the total separated component α is 51 mass% or more, and a separated component γ in which the proportion of component C in the total separated component γ is 51 mass% or more.

[0032] A liquid component is used as component A. If component A is solid at normal temperature, it can be liquefied and used by heating.

[0033] Examples of component A include aromatic hydrocarbons, alcohols, esters, carbonates, ethers, ketones, halogenated hydrocarbons, amides and sulfoxides.

[0034] Examples of aromatic hydrocarbons include benzene, ethylbenzene, toluene, xylene, mesitylene, cymene, cumene and pseudocumene.

[0035] Examples of the alcohols include aliphatic alcohols (methanol, ethanol, propanol, butanol, hexanol and the like) and aromatic alcohols (benzyl alcohol and the like).

[0036] Examples of the esters include aliphatic carboxylic acid esters (methyl acetate, ethyl acetate, butyl acetate, vinyl acetate, ethyl propionate, ethyl butyrate and the like).

[0037] Examples of the carbonates include chain carbonates (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, dipropyl carbonate and the like) and cyclic carbonates (propylene carbonate, ethylene carbonate, butylene carbonate and the like).

[0038] Examples of the ethers include chain ethers (diethyl ether, ethyl propyl ether, ethyl isopropyl ether and the like) and cyclic ethers (tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran and the like).

[0039] Examples of ketones include acetone, methyl ethyl ketone, pentanone, hexanone, heptanone and cyclohexanone.

[0040] Examples of halogenated hydrocarbons include dichloroethane and trichloromethane.

[0041] Examples of the amides include N-methyl-2-pyrrolidone and N,N-dimethylformamide.

[0042] Examples of sulfoxides include dimethyl sulfoxide.

[0043] Both liquid and solid components can be used as component B. If component B is solid at normal temperature, it can be liquefied and used by heating.

[0044] Examples of liquid component B include terpenes (terpene hydrocarbons such as myrcene, limonene, pinene, camphor, sabinene, phellandrene, paracymene, ocimene, terpinene, carene, zingiberene, caryophyllene, bisabolene and cedrene; terpene aldehydes such as citronellal, citral, cyclocitral, safranal, phellandral, perillaldehyde, geranial, neral; and terpene ketones such as camphor and thujone).

[0045] Examples of the solid component B include polyolefin resins (polymers such as polypropylene, polyethylene and cycloolefins), polystyrene resins and rubbers (ethylene propylene rubber and the like).

[0046] A liquid component is used as component C. If component C is solid at normal temperature, it can be liquefied and used by heating.

[0047] Examples of component C include carbonates, polyhydric alcohols and water.

[0048] Examples of carbonates include those described above for component A.

[0049] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, diethylene glycol, dipropylene glycol and glycerin.

[0050] Among them, from the viewpoint of separability and ease of adjustment of T2, component C is preferably at least one selected from the group consisting of cyclic carbonates and polyhydric alcohols, preferably at least two selected from the group consisting of cyclic carbonates and polyhydric alcohols, more preferably ethylene carbonate and at least one selected from the group consisting of cyclic carbonates other than ethylene carbonate and polyhydric alcohols, and particularly preferably ethylene carbonate and at least one selected from the group consisting of propylene carbonate and ethylene glycol.

[0051] In particular, ethylene carbonate has a highly symmetric molecular structure, exhibits strong intermolecular interactions, and in a mixed system, causes a phase change of uniform mixing and separation at a relatively high temperature. Due to the nature of ethylene carbonate, each component can be easily separated by a mild cooling process in a mixed system of ethylene carbonate and other components. Furthermore, ethylene carbonate is known as a highly polar solvent used in electrolytic solutions and the like, and has the property of being easily dissolved in a polar substance.Therefore, even in a mixed system of a polar solvent and a non-polar solvent that does not originally contain ethylene carbonate, the non-polar solvent can be separated by extracting the polar solvent with ethylene carbonate, and the ethylene carbonate and the polar solvent can be separated by a cooling process.

[0052] Therefore, component C preferably comprises ethylene carbonate and is more preferably ethylene carbonate.

[0053] Next, details of the component separation system (or the component separation method) according to the present embodiment will be described. <Erste Separationseinheit (oder erster Separationsprozess, dasselbe gilt nachfolgend)>(First embodiment)

[0054] The first separation unit according to the first embodiment is, for example, as shown in Fig. 3, a separation unit configured to: add the liquid component C as an extractant for the component A to the mixed component αβ in which the liquid component A and the liquid component B are uniformly mixed, to extract the component A with the component C; and perform liquid-liquid separation of the separated component αγ and the separated component β.

[0055] In the first separation unit according to the first embodiment, the mixed component αβ is prepared. The ratio of component A to component B (component A / component B) in the mixed component αβ is, for example, 10 / 1 to 1 / 10 in terms of a mass ratio. Component A and component B can be mixed to prepare the mixed component αβ while being adjusted to a temperature at which component A and component B are uniformly mixed.

[0056] Next, component C is added to the mixed component αβ to obtain the mixed component αβγ.

[0057] Then, the temperature of the mixed component αβγ is controlled to temperature T1. For example, temperature T1 is within a range of 40°C or higher and the boiling point of each component or lower.

[0058] The process of tempering the mixed component αβγ to temperature T1 can be a process of raising the temperature of the mixed component αβγ or a cooling process. Furthermore, the temperatures of the mixed component αβ and component C can be set in advance such that the temperature of the mixed component αβγ becomes temperature T1 when component C is added to the mixed component αβ.

[0059] In the mixed component αβγ to which component C is added, the separated component αγ and the separated component β are phase-separated by extracting component A with component C. Then, the separated component αγ and the separated component β are separated by a liquid-liquid separation process. A known method, such as a method using a separatory funnel, can be used as the liquid-liquid separation process.

[0060] The number of times of the extraction process and the liquid-liquid separation process and the addition amount of the component C are determined, for example, from the distribution coefficient of the component A in the mixed component αβγ and the amount of the mixed component αβ.

[0061] Here, in the first separation unit according to the first embodiment, in a case where the proportion of component B in the mixed component αβ is small, the influence of component A becomes dominant, and in the mixed component αβγ, phase separation between the separated component αγ and the separated component β can hardly occur. In this case, as shown in Fig. 4, the separated component β may be reused, the separated component β may be added in addition to the mixed component αβ, and the proportion of component B in the mixed component αβ may be increased to be in the above range.

[0062] Incidentally, the component B may be prepared separately, and the component B may be further added to the mixed component αβ to increase the proportion of the component B in the mixed component αβ. (Second embodiment)

[0063] In the first separation unit according to the second embodiment, for example, as shown in Fig. 5, the first separation unit is a separation unit configured to: add the liquid component C, which is a poor solvent for the component B, to the mixed component αβ in which the solid component B is dissolved in the liquid component A, which is a good solvent for the component B, to precipitate the component B; and perform solid-liquid separation of the separated component αγ and the separated component β.

[0064] In the first separation unit according to the second embodiment, the mixed component αβ is prepared. The ratio of component A to component B (component A / component B) in the mixed component αβ is, for example, 1000 / 1 to 10 / 1 in terms of a mass ratio. The mixed component αβ can be prepared by adjusting the temperature so that component B dissolves in component A.

[0065] Next, component C is added to the mixed component αβ to obtain the mixed component αβγ.

[0066] Then, the temperature of the mixed component αβγ is controlled to be the temperature T1. The range of the temperature T1 and the method for adjusting the temperature of the mixed component αβγ to the temperature T1 are the same as those of the first separation unit according to the first embodiment.

[0067] In the mixed component αβγ to which component C is added, the solubility of component B changes, and component B precipitates. Then, the separated component αγ and the separated component β are separated by a solid-liquid separation process. Well-known methods such as filtration, centrifugation, and decantation can be used for the solid-liquid separation process.

[0068] Here, in the first separation unit according to the second embodiment, in a case that impurities are mixed into the mixed component αβ as shown in Fig. As shown in Figure 6, before component C is added to the mixed component αβ, impurity removal processing is performed. As a method for removing impurities, known methods such as a method using an adsorbent, filtration, centrifugation, and decantation can be used. <Zweite Separationseinheit (zweiter Separationsprozess, dasselbe gilt nachfolgend)>

[0069] As in Fig. 7 and Fig. 8, the second separation unit according to the present embodiment is a separation unit configured to change the temperature of the separated component αγ to a temperature T2 for separating the separated component αγ into the separated component α containing the component A as a main component and the separated component γ containing the component C as a main component.

[0070] In the second separation unit according to the present embodiment, the temperature of the separated component αγ is controlled to the temperature T2, but in a case where component A and component C exhibit the UCST-like separation behavior, the temperature T2 of the separated component αγ is made lower than the temperature T1. That is, the temperature T2 is set to be lower than the temperature T1 by cooling the separated component αγ so that the relationship of temperature T1 > temperature T2 is established.

[0071] On the other hand, in a case where component A and component C exhibit LCST-like separation behavior, the temperature T2 of the separated component αγ is set higher than the temperature T1. That is, the temperature T2 is set higher than the temperature T1 by increasing the temperature of the separated component αγ so that the relationship of temperature T1 < temperature T2 is established.

[0072] Here, the temperature T2 can be adjusted by the proportion of component A or component C, preferably the proportion of component C, in the separated component αγ. Therefore, in the first separation unit according to the first and second embodiments described above, it is preferable to adjust the types of component A and component C and the addition amount of component C to achieve the target temperature T2.

[0073] For example, the difference (absolute value) between temperature T1 and temperature T2 is within a range of 10°C or higher.

[0074] When the temperature of the separated component αγ reaches the temperature T2 through tempering, the separated component α and the separated component γ are phase-separated due to equilibrium shift. Then, the separated component αγ and the separated component γ are separated by a liquid-liquid separation process (see Fig. 7). As the liquid-liquid separation process, a known method such as a method using a separatory funnel can be used.

[0075] However, if the temperature of the separated component αγ is adjusted to be the temperature T2 by tempering operation, the component A or the component C precipitates when the temperature T2 falls below the melting point of the component A or the component C (see Fig. 8). In this case, the separated component αγ and the separated component γ are separated by a solid-liquid separation process. Well-known methods such as filtration, centrifugation, and decantation can be used for the solid-liquid separation process.

[0076] In addition, the temperature T2 can be adjusted by the composition of component A or component C in the separated component αγ.

[0077] By controlling the temperature T2 through the composition of component A or component C in the separated component αγ, the component separation energy can be reduced. For example, in a case where component A and component C exhibit the UCST-like phase change behavior, it is necessary to satisfy T1 > phase change temperature > T2. However, by bringing the phase change temperature close to T1, T2 can also be increased, and the consumed energy corresponding to the temperature change between T1 and T2 can be reduced. In addition, controlling the phase change temperature is also effective in a case where it is desired to set T1 and T2 to be equal to or lower than the boiling point and equal to or higher than the freezing point of each component.

[0078] In a case where the temperature T2 is adjusted by the composition of the component A in the separated component αγ, the component A is preferably two or more compounds, more preferably at least two selected from the group consisting of aromatic hydrocarbons, alcohols, halogenated hydrocarbons, amides and sulfoxides, even more preferably at least two selected from the group consisting of aromatic hydrocarbons and alcohols, and particularly preferably two aromatic hydrocarbons or two alcohols, from the viewpoint of separability and ease of adjustment of T2.

[0079] As the aromatic hydrocarbons, when two or more kinds are used as the component A, from the viewpoint of separability and ease of adjustment of T2, two or more kinds selected from the group consisting of benzene, ethylbenzene, toluene, xylene, mesitylene, cymene, cumene and pseudocumene are preferable, two or more kinds selected from the group consisting of toluene, xylene, mesitylene, cymene and cumene are more preferable, and toluene and xylene are particularly preferable.

[0080] As the alcohols in the case of using two or more kinds as the component A, from the viewpoint of separability and ease of adjustment of T2, two or more kinds of aliphatic alcohols are preferable, two or more kinds selected from the group consisting of methanol, ethanol, propanol, butanol and hexanol are more preferable, and ethanol and 1-propanol are particularly preferable.

[0081] Fig. 18 and Fig. 19 shows phase change temperatures in a case where aromatic hydrocarbons and alcohols are used as component A, ethylene carbonate is used as component C, and the composition of component A is changed. The phase change temperature is a value when the mass ratio of component A to component C is 1:1. Furthermore, the mixed solvent of component A and component C was stirred while changing the temperature, and the phase change temperature was recorded by observing the change in the brightness of the solvent.

[0082] First, in the case of aromatic hydrocarbons, a solvent obtained by mixing toluene and xylene was used, and, as in Fig. As shown in Figure 18, it was confirmed that the phase change temperature increased as the xylene content increased. Furthermore, the behavior of the phase change temperature can be approximated by a quadratic curve with respect to the xylene content, and it is shown that the phase change temperature can be predicted even in an unmeasured composition.

[0083] Subsequently, in the case of alcohols, a solvent obtained by mixing ethanol and 1-propanol was used and, as in Fig. 19, it was confirmed that the phase change temperature increases as the proportion of 1-propanol increases, and the result that the behavior of the phase change temperature can be approximated by a quadratic curve with respect to the proportion of 1-propanol, as in the case of aromatic hydrocarbons, was obtained.

[0084] By applying these results and adjusting the composition of component A, the phase change temperature can be controlled. In this example, a combination of toluene and xylene and a combination of ethanol and 1-propanol were described, but it is also possible to control the phase change temperature over a wider range using substances from other aromatic hydrocarbons and alcohols.

[0085] In a case where the temperature T2 is adjusted by the composition of the component C in the separated component αγ, the component C is preferably two or more compounds, more preferably ethylene carbonate and at least one selected from the group consisting of cyclic carbonates other than ethylene carbonate and polyhydric alcohols, and particularly preferably ethylene carbonate and at least one selected from the group consisting of propylene carbonate and ethylene glycol, from the viewpoint of separability and ease of adjustment of T2.

[0086] The phase change temperature in a case that xylene or p-cymene is used as the component A, a mixed solvent of ethylene carbonate (EC) and propylene carbonate (PC) or a mixed solvent of ethylene carbonate and ethylene glycol (EG) is used as the component C, and the composition of the component C is changed is Fig. 20 to 22. The phase change temperature is a value when the mass ratio of component A to component C is 1:1. Furthermore, the mixed solvent of component A and component C was stirred while changing the temperature, and the phase change temperature was recorded by observing the change in the brightness of the solvent.

[0087] First, in the case of using a mixed solvent of ethylene carbonate and propylene carbonate, it has been confirmed that the phase change temperature increases as the proportion of ethylene carbonate increases, as shown in Fig. 20 and Fig. 21. This is because propylene carbonate is a solvent miscible with xylene and p-cymene, and separation becomes difficult due to a decrease in the proportion of propylene carbonate.

[0088] Subsequently, in the case where a mixed solvent of ethylene carbonate and ethylene glycol was used, it was confirmed as in Fig. As shown in Figure 22, the phase change temperature decreases as the proportion of ethylene carbonate increases. This is because ethylene glycol is a solvent that separates from xylene, and separation becomes easy as the proportion of ethylene glycol decreases.

[0089] By applying these results and adjusting the composition of component C, the phase change temperature can be controlled. In this example, the combination of ethylene carbonate and propylene carbonate and the combination of ethylene carbonate and ethylene glycol have been described. However, by selecting a suitable substance according to its phase equilibrium behavior with component A, the phase change temperature can be controlled over a wider range. It can also be combined with the composition adjustment of component A. <Andere Aspekte> (First embodiment)

[0090] The component separation system having the first separation unit according to the first embodiment can be applied to a solid substance purification system (hereinafter, the “solid substance purification system according to the first embodiment”).

[0091] In the solid substance purification system according to the first embodiment, as shown in Fig. 9, a solid substance mixed with impurities is subjected to a dissolving process by adding the liquid component B, which serves as a good solvent for the solid substance, to dissolve the solid substance in the component B. Thereby, a solution containing the component B, the solid substance, and the impurities is obtained.

[0092] Next, component A as a poor solvent for the solid substance is added to the solution, and the solid substance is precipitated through a reprecipitation process to separate the solid substance and impurities. In other words, in the component separation system having the first separation unit according to the first embodiment, the mixed component αβ corresponds to a mixed system after reprecipitation of the solid substance and is a mixed component in which component A as a poor solvent for the solid substance and component B as a good solvent for the solid substance are uniformly mixed.

[0093] Then, separation is carried out by the component separation system having the first separation unit according to the first embodiment using the remaining mixed component αβ containing the component A and the component B as a main component.

[0094] Accordingly, in the solid substance purification system according to the first embodiment, each component can be separated together with the purification of the solid substance.

[0095] In the solid substance purification system according to the first embodiment (and the component separation system having the first separation unit according to the first embodiment), a preferable example is a combination in which the solid substance is a resin (particularly, a styrene resin), component A is an alcohol, component B is a terpene, and component C is ethylene carbonate.

[0096] In the solid substance purification system according to the first embodiment (and the component separation system having the first separation unit according to the first embodiment), the separated components α, β and γ can be reused, respectively. (Second embodiment)

[0097] The component separation system having the first separation unit according to the second embodiment can be applied to a solid substance purification system (hereinafter, the “solid substance purification system according to the second embodiment”).

[0098] In the solid substance purification system according to the second embodiment, as shown in Fig. 10, the solid component B mixed with impurities is subjected to a dissolving process by adding the liquid component A, which serves as a good solvent for the solid substance, to dissolve the component B in the component A. As a result, the component B is dissolved in the component A to obtain the mixed component αγ containing impurities.

[0099] Next, impurity removal processing is performed on the mixed component αγ to remove impurities.

[0100] Then, separation is carried out by the component separation system having the first separation unit according to the second embodiment using the remaining mixed component αβ containing the component A and the component B.

[0101] Accordingly, in the solid substance purification system according to the second embodiment, each component can be separated together with the purification of the solid component B.

[0102] In the solid substance purification system according to the second embodiment (and the component separation system having the first separation unit of the second embodiment), a preferable example is a combination in which component A is an aromatic hydrocarbon, component B is a resin (particularly, a polyolefin resin), and component C is ethylene carbonate.

[0103] In the solid substance purification system according to the second embodiment (and the component separation system having the first separation unit according to the second embodiment), the separated components α and γ can be reused, respectively. EXAMPLES

[0104] Below, the disclosure is described in more detail with reference to examples, but the disclosure is not limited to these examples. Furthermore, examples were carried out under normal pressure. [Example 1: Reprecipitation of polystyrene resin and component separation]

[0105] An example in which the component separation system of the disclosure is applied to a polystyrene resin purification system is described.

[0106] First, 300 mg of a polystyrene resin was completely dissolved in 15 g of d-limonene (an example of component B) as a good solvent at room temperature to obtain a polystyrene resin solution.

[0107] Next, 15 g of ethanol (an example of component A) as a poor solvent was added to the polystyrene resin solution, and the solution was stirred well to precipitate a polystyrene resin.

[0108] Next, a polystyrene resin precipitate was separated from the polystyrene resin solution by centrifugation. To a remaining mixed solvent αβ (an example of mixed component αβ) containing d-limonene and ethanol in a mass ratio of 1:1, 10 g of ethylene carbonate (an example of component C) liquefied by heating at 40°C was added, and the mixture was shaken well to obtain a mixed solvent αβγ (an example of mixed component αβγ).

[0109] Then, the temperature of the mixed solvent αβγ became a temperature T1=40°C, and the phase was separated into the upper layer liquid and the lower layer liquid. A liquid-liquid separation process was carried out to separate the upper layer liquid and the lower layer liquid using a separatory funnel. 12 g of ethylene carbonate was added again to the remaining upper layer liquid and the lower layer liquid. After stirring, the liquid-liquid separation process was carried out on the upper layer liquid and the lower layer liquid using a separatory funnel. The same process was repeated two more times. The liquid temperature during the process was fixed at a temperature T1=40°C.

[0110] The upper layer liquid after the extraction process was a separated solvent β (an example of the separated component β) containing ethylene carbonate, ethanol, and d-limonene with a mass ratio of 3.5:15.6:80.9, and with d-limonene as a major component. The separated solvent β contains 15.6 mass% of ethanol, but in a case where the proportion of ethanol is 20 mass% or less, as shown in Fig. As shown in Figure 11, the mixed solvent of d-limonene and ethanol was assumed to act as a good solvent for the polystyrene resin. When 300 mg of the polystyrene resin was actually added to the separated solvent β, the polystyrene resin was completely dissolved, and it was demonstrated that the separated solvent β recovered through this series of operations could be reused for the reprecipitation process of the polystyrene resin.

[0111] On the other hand, the underlayer liquid after the extraction process was a separated solvent αγ (an example of the separated component αγ) containing ethylene carbonate, ethanol and d-limonene in a mass ratio of 62.2 : 34.5 : 3.3.

[0112] Next, the separated solvent αγ was allowed to stand and cool at 4°C for 15 minutes. When the temperature of the separated solvent αγ reached a temperature T2=4°C, a precipitate γ of component C (an example of the separated component γ) was deposited on the bottom of the container. Then, the separated solvent α and the precipitate γ of component C were subjected to solid-liquid separation by filtration and centrifugation.

[0113] The separated solvent α was a liquid consisting mainly of ethanol, containing ethylene carbonate, ethanol, and d-limonene in a mass ratio of 7.8:58.7:33.5. The separated solvent α was recovered in a state that made it reusable as a poor solvent in the reprecipitation process of the polystyrene resin.

[0114] Subsequently, the energy consumed per 1 kg of polystyrene resin for component separation during the polystyrene resin reprecipitation process, including solvent recovery after reprecipitation, was calculated. This calculation was performed assuming that d-limonene and ethanol were used in a mass ratio of 50 times, and ethylene carbonate was used in a mass ratio of 150 times to the polystyrene resin, the thermal efficiency of each process was 25%, and the separation process efficiency was 100%. Furthermore, the values ​​described in the NIST databook were used for the thermophysical properties of each component.

[0115] This calculation does not take into account the specific heat and the heat of solution of the polystyrene resin and the heat for uniform mixing of the solvents.

[0116] The calculation results are in Fig. 12 shown. Fig. 12(A) shows a calculation result of the component separation system of Example 1, and Fig. Figure 12(A) shows a result of the component separation system according to a conventional distillation process.

[0117] The calculation results that while the consumed energy according to the conventional method was about 643 [MJ / kg-PS], the consumed energy was reduced to about 281 [MJ / kg-PS] using the component separation system of Example 1 were obtained.

[0118] Here, the conventional process was considered as a system in which 1) a polystyrene resin (PS) is dissolved in d-limonene at 25°C, 2) ethanol is added to a polystyrene resin solution to precipitate and separate the polystyrene resin, and 3) d-limonene and ethanol are separated by distillation. [Example 2: Reprecipitation of polypropylene resin and component separation]

[0119] An example in which the component separation system of the disclosure is applied to a purification system of a polypropylene resin (an example of component B) will be described.

[0120] 300 mg of the polypropylene resin (an example of component B) was completely dissolved in 15 g of xylene (an example of component A) as a good solvent at 130°C to obtain a polypropylene resin solution αβ (an example of the mixed component αβ).

[0121] Next, 15 g of ethylene carbonate (an example of component C) liquefied by heating at 40°C was added to the polypropylene resin solution αβ, and the mixture was thoroughly stirred at a temperature T1=88°C to obtain a mixed solution αβγ (an example of the mixed component αβγ). The precipitate β of the polypropylene resin (an example of the separated component β) was precipitated. The precipitate β of the polypropylene resin was precipitated at the moment when ethylene carbonate was added to the polypropylene resin solution αβ.

[0122] Then, the precipitate β of the polypropylene resin was recovered by filtration.

[0123] Next, the remaining mixed solvent αγ (an example of the separated component αγ), containing xylene and ethylene carbonate in a mass ratio of 1:1, was left at room temperature. Separation gradually occurred when the temperature of the mixed solvent αγ reached 70°C or lower, and a clear liquid-liquid interface appeared when the temperature T2 reached 40°C or lower, thus resulting in phase separation between the upper-layer liquid and the lower-layer liquid.

[0124] Next, the liquid-liquid separation process was carried out to separate the upper layer liquid and the lower layer liquid using a separatory funnel.

[0125] From the liquid-liquid equilibrium diagram of the ethylene carbonate-xylene system shown in Fig. 13, it is estimated that the upper layer liquid is the separated solvent α (an example of the separated component α) containing xylene as a main component and about 10 mass% of ethylene carbonate, and the lower layer liquid is the separated solvent γ (an example of the separated component γ) containing ethylene carbonate as a main component and about 20 mass% of ethylene.

[0126] In Fig. 13 represents M EC represents the mass of ethylene carbonate, M Xylol represents the mass of xylene, and represents T C the temperature of the system.

[0127] Here, as in Fig. 14, in a case that the content of ethylene carbonate is 20 mass% or less, since the mixed solvent of ethylene carbonate and xylene acts as a good solvent for polypropylene, it can be assumed that the separated solvent α can be reused as a good solvent for the polypropylene resin.

[0128] Next, similar to Example 1, the energy consumed in the reprecipitation process of the polypropylene resin was also calculated. This calculation considered that xylene and ethylene carbonate were used in a mass ratio of 50 times that of the polypropylene resin, and the other conditions were the same as those of Example 1.

[0129] The calculation results are in Fig. 15 shown. Fig. 15(A) shows a calculation result of the component separation system of Example 2, and Fig. Figure 15(B) shows a result of the component separation system according to a conventional distillation process.

[0130] The calculation results that while the consumed energy according to the conventional method was about 480 [MJ / kg-PP], the consumed energy was reduced to about 63 [MJ / kg-PP] using the component separation system of Example 2 were obtained.

[0131] Here, the conventional method was adopted as a system in which 1) a polypropylene resin (PP) is dissolved in xylene at 130°C, 2) a polypropylene resin solution is cooled to 40°C, 3) acetone is added at 40°C to the polypropylene resin solution to precipitate and separate the polypropylene resin, and 3) xylene and acetone are separated by distillation. [Example 3: Reprecipitation of polyethylene resin and component separation]

[0132] An example in which the component separation system of the disclosure is applied to a purification system of a polyethylene resin (an example of component B) will be described.

[0133] 300 mg of the polyethylene resin (an example of component B) was completely dissolved in 15 g of xylene (an example of component A) at 115°C to obtain the polyethylene resin solution αβ (an example of the mixed component αβ).

[0134] Next, 15 g of ethylene carbonate (an example of component C) liquefied by heating at 40°C was added to the polyethylene resin solution αβ, and the mixture was thoroughly stirred at a temperature T1=80°C to obtain the mixed solution αβγ (an example of the mixed component αβγ). The precipitate β of the polyethylene resin (an example of the separated component β) was precipitated. The precipitate β of the polyethylene resin was precipitated at the moment when ethylene carbonate was added to the polyethylene resin solution αβ.

[0135] Then, the precipitate β of the polyethylene resin was recovered by filtration.

[0136] The remaining mixed solvent αγ (an example of the separated component αγ), containing xylene and ethylene carbonate in a mass ratio of 1:1, was left at room temperature. Separation gradually occurred when the temperature of the mixed solvent αγ reached 70°C or lower, and a clear liquid-liquid interface appeared when the temperature T2 reached 40°C or lower, thus resulting in phase separation between the upper-layer liquid and the lower-layer liquid.

[0137] Next, the liquid-liquid separation process was carried out to separate the upper layer liquid and the lower layer liquid using a separatory funnel.

[0138] From the liquid-liquid equilibrium diagram of ethylene carbonate-xylene, which is shown in Fig. 13, it is estimated that the upper layer liquid is the separated solvent α (an example of the separated component α) containing xylene as a main component and about 10 mass% of ethylene carbonate, and the lower layer liquid is the separated solvent (an example of the separated component γ) containing ethylene carbonate as a main component and about 20 mass% of xylene.

[0139] Here, as in Fig. 16, in a case that the content of ethylene carbonate is 20 mass% or less, since the mixed solvent of ethylene carbonate and xylene acts as a good solvent for the polypropylene resin, it can be considered that the separated solvent α can be reused as a good solvent for the polyethylene resin.

[0140] Next, the energy consumed in the reprecipitation process of the polyethylene resin was calculated similarly to the case of Example 2. The calculation conditions were exactly the same as in Example 2. The calculation results are shown in Fig. 17 shown. Fig. 17(A) shows a calculation result of the component separation system of Example 3, and Fig. Figure 17(B) shows a result of the component separation system according to a conventional distillation process.

[0141] The calculation results that while the consumed energy according to the conventional method was about 470 [MJ / kg-PE], the consumed energy was reduced to about 52 [MJ / kg-PE] using the component separation system of Example 3 were obtained.

[0142] Here, the conventional method was adopted as a system in which 1) the polyethylene resin (PP) is dissolved in xylene at 115°C, 2) the polyethylene resin solution is cooled to 40°C, 3) acetone is added to the ethylene resin solution at 40°C to precipitate and separate the polyethylene resin, and 3) xylene and acetone are separated by distillation. [Example 4: Reprecipitation process of polypropylene]

[0143] 300 mg of polypropylene was completely dissolved in 15 g of xylene at 130°C. When 13 g of ethylene carbonate and 3 g of ethylene glycol were added to this polypropylene solution and stirred thoroughly, the polypropylene precipitated. This polypropylene precipitate was recovered by filtration, and the remaining mixed solution of xylene, ethylene carbonate, and ethylene glycol was allowed to stand until the temperature reached 80°C, and a clear liquid-liquid interface was formed. This solution was separated into an upper layer liquid and a lower layer liquid using a separatory funnel. When 300 mg of new polypropylene was completely dissolved in the recovered upper layer liquid at 130°C, this polypropylene solution was added to the recovered lower layer liquid, and the mixture was stirred thoroughly, the polypropylene precipitated.In the same manner as in the first procedure, a polypropylene precipitate was recovered by filtration, and the remaining mixed solvent was allowed to stand until the temperature reached 80°C, and a distinct liquid-liquid interface was formed. This solution was separated into an upper layer liquid and a lower layer liquid using a separatory funnel. As a result, it was confirmed that the solvent system used in this test can be used repeatedly by separating it by phase change. The yield of the polypropylene precipitate recovered in the first and second procedures was 90% or more.

[0144] Subsequently, in the reprecipitation process of polypropylene in Example 2 and Example 4, the energy consumed per 1 kg of polypropylene in the process, including solvent recovery after reprecipitation, was calculated. In this calculation, the calculation was performed assuming that a mixed solvent containing xylene, ethylene carbonate, and ethylene glycol in a ratio of 4:1 (mass ratio) was used at 50 times the mass ratio of polypropylene, the thermal efficiency of each process was 25%, and the separation process efficiency was 100%. Furthermore, for the thermophysical properties of each substance, reference was made to the values ​​described in the NIST data book. This calculation does not take into account the specific heat or heat of solution of polypropylene, nor the heat of uniform mixing of the solvents. The calculation results are shown in Fig. 23 shown. Fig. 23(a) shows a calculation result of a case of Example 2, and Fig. 23(b) shows a result of a case of Example 4. This time, the calculation results were obtained that while the consumed energy in Example 2 was about 63 [MJ / kg-PP], the consumed energy in Example 4 was reduced to about 35 [MJ / kg-PP].

[0145] From the above, it can be understood that the component separation system of the present example is capable of separating components under normal pressure without using distillation and with energy saving.

[0146] In addition, it can be understood that the component separation system of the present example can carry out component separation together with purification of solid substance.

[0147] The disclosures of Japanese Patent Application No. 2023-015498 filed on February 3, 2023, and Japanese Patent Application No. 2023-184258 filed on October 26, 2023, are incorporated herein by reference in their entirety.

[0148] All publications, patent applications, and technical standards cited in this specification are incorporated herein by reference to the same extent as if each individual publication, patent application, or technical standard were specifically and individually indicated to be incorporated by reference. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2021-526575

[0004] JP 2023-015498

[0147] JP 2023-184258

[0147]

Claims

[1] Component separation system, with: a first separation unit configured to: add a component C to a single-phase mixed component αβ containing a component A and a component B; and separate a mixed component αβγ containing component A, component B, and component C at a temperature T1 into a separated component αγ containing component A and component C as a main component, and a separated component β containing component B as a main component; and a second separation unit configured to change a temperature of the separated component αγ to a temperature T2 for separating the separated component αγ into a separated component α containing component A as a main component and a separated component γ containing component C as a main component, in which component C has a miscible behavior with respect to component A at the temperature T1 of the mixed component αβγ, a separation behavior with respect to component B at the temperature T1 of the mixed component αβγ and exhibits a separation behavior with respect to component A at the temperature T2 of the separated component αγ. [2] The component separation system according to claim 1, wherein the first separation unit is a separation unit configured to: add the component C as an extractant for the component A to the mixed component αβ in which the component A in a liquid state and the component B in a liquid state are uniformly mixed, to extract the component A with the component C; and perform liquid-liquid separation of the separated component αγ and the separated component β. [3] A component separation system according to claim 2, wherein the mixed component αβ is a mixed system after reprecipitation of a solid substance and is a mixed component in which component A as a poor solvent for the solid substance and component B as a good solvent for the solid substance are uniformly mixed. [4] A component separation system according to claim 3, wherein: the solid substance is a styrene resin, component A is an alcohol, component B is a terpene, and component C is ethylene carbonate. [5] The component separation system according to claim 1, wherein the first separation unit is a separation unit configured to: add the component C in a liquid state as a poor solvent for the component B to the mixed component αβ in which the component B in a solid state is dissolved in the component A in a liquid state which is a good solvent for the component B, to precipitate the component B; and carry out solid-liquid separation of the separated component αγ and the separated component β. [6] A component separation system according to claim 5, wherein: component A is an aromatic hydrocarbon, component B is a polyolefin resin, and component C is ethylene carbonate. [7] A component separation system according to claim 2 or 5, wherein the temperature T2 is adjusted based on a proportion of the component A or the component C in the separated component αγ. [8] A component separation system according to claim 2 or 5, wherein the temperature T2 is adjusted based on a composition of the component A or the component C in the separated component αγ. [9] A component separation system according to claim 8, wherein: component A is at least one selected from the group consisting of aromatic hydrocarbons and alcohols, component B is a polyolefin resin, and component C contains ethylene carbonate. [10] A component separation system according to claim 9, wherein component A is two aromatic hydrocarbons or two alcohols. [11] A component separation system according to claim 9, wherein component C is ethylene carbonate and at least one selected from the group consisting of cyclic carbonates other than ethylene carbonate and polyhydric alcohols.

Images