Process for the purification of liquid organic compounds

Abstract

The present invention provides a method for effectively removing nitrogen-containing compounds and halogen-containing compounds from a liquid organic compound containing nitrogen-containing compounds and halogen-containing compounds, preferably a decomposition oil of waste plastics. The present invention includes a method for refining a liquid organic compound, which has a step of separating a monofunctional organic compound (A) and a polyfunctional compound (B) after bringing a liquid organic compound (RM) containing nitrogen-containing compounds, halogen-containing compounds, and hydrocarbon compounds, the monofunctional organic compound (A), and the polyfunctional compound (B) into contact. The method satisfies the following requirements (i) to (iv). (i) The monofunctional organic compound (A) is a compound containing carbon, hydrogen, and oxygen, and has a Hansen solubility parameter value [HSP-a] of 15 to 35 MPa 0.5 , (ii) The polyfunctional compound (B) is a compound containing two or more elements selected from carbon, hydrogen, and oxygen, and has a Hansen solubility parameter value [HSP-b] of 20 to 60 MPa 0.5 , (iii) The value of [HSP-b] - [HSP-a] is 3 to 40 MPa 0.5 , and (iv) The mass ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) is 10 / 90 to 95 / 5.

Description

Technical Field

[0001] This invention relates to a method for purifying liquid organic compounds. Background Technology

[0002] In recent years, there has been a growing emphasis on environmental issues. This includes mentioning global warming and marine pollution caused by plastics, and researching countermeasures such as reducing the use of fossil resources like oil and coal, preventing the disposal of waste plastics, and promoting recycling.

[0003] It is well known that general-purpose resins such as polyolefins and polyvinyl chloride, as well as functional resins such as polyamides, polyethers, and polysulfides, can be easily converted into oils through thermal decomposition, yielding decomposed oils. These oils are strong candidates for the reuse of already used resins. For example, a systematic method can be proposed to use these decomposed oils as naphtha for reuse in the existing petrochemical industry. Such methods are considered more effective for materials with low levels of sorting and recycling.

[0004] On the other hand, it is practically difficult to completely separate and recycle resins by type from everyday life. As a result, most plastic decomposition oils contain: polyamides, such as nylon; nitrogen-containing compounds derived from the reaction of nitrogen in the air with the plastic during the aforementioned oily decomposition process; and / or chlorine-containing compounds derived from polyvinyl chloride (PVC). Various stabilizing materials used in resin molding sometimes also become sources of such heteroatoms. These heteroatom-containing compounds sometimes act as catalyst poisons in downstream processes, cause equipment corrosion, etc., and therefore are usually required to be removed.

[0005] As a method for solving such problems, there are disclosed methods for hydrogenating the above-mentioned decomposed oil (Patent Document 1), methods for steam treatment (Patent Document 2), methods for contacting it with inorganic acids (Patent Document 3), methods for contacting it with alkaline compounds and water (Patent Document 4), and methods for contacting it with solid compounds such as metal oxides (Patent Document 5).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 9-48983

[0009] Patent Document 2: Japanese Patent Application Publication No. 9-48981

[0010] Patent Document 3: Japanese Patent Application Publication No. 9-48982

[0011] Patent Document 4: Japanese Patent Application Publication No. 2003-34794

[0012] Patent Document 5: Japanese Patent Publication No. 11-504672 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] The methods in Patent Documents 1-5 are effective in reducing compounds containing nitrogen, chlorine, and other heteroatoms from decomposed oils. However, the methods described above sometimes require relatively high energy. Furthermore, each method is difficult to completely remove unwanted substances. According to the inventors' research, the following results have been obtained: for specific heteroatom-containing compounds, such as compounds with carbon-nitrogen multiple bond structures like cyano groups, and nitrogen-containing cyclic compounds like pyrroles, the residue rate is sometimes relatively high when using the methods in Patent Documents 1-5. In such cases, it is sometimes combined with a simpler and more effective method for removing heteroatom-containing components, but there is still room for improvement.

[0015] In view of such problems, the objective of the present invention is to provide a method for more effectively removing the aforementioned nitrogen-containing compounds and halogen-containing compounds from liquid organic compounds (RM) containing carbon, hydrogen, nitrogen and halogens, such as polymer decomposition oils, using a simple method.

[0016] Methods for solving problems

[0017] The inventors conducted in-depth research and discovered that compounds containing specific multiple compounds can effectively extract and remove nitrogen-containing and halogen-containing compounds from the aforementioned liquid organic compounds, thus completing this invention. Therefore, this invention can be defined by the following structure.

[0018] [1] A method for purifying a liquid organic compound, comprising the following steps: contacting a liquid organic compound (RM) containing a nitrogen-containing compound, a halogen-containing compound and a hydrocarbon compound, a monofunctional organic compound (A) and a polyfunctional compound (B) together, and then separating the monofunctional organic compound (A) and the polyfunctional compound (B).

[0019] The above method satisfies the requirements (i) to (iv) below.

[0020] (i) The above-mentioned monofunctional organic compound (A) is a compound containing carbon, hydrogen and oxygen, and its Hansen solubility parameter [HSP-a] is 15~35 MPa. 0.5 ;

[0021] (ii) The above-mentioned multifunctional compound (B) is a compound containing two or more elements selected from carbon, hydrogen and oxygen, and the Hansen solubility parameter [HSP-b] is 20~60 MPa. 0.5 ;

[0022] (iii) The value of [HSP-b]-[HSP-a] is 3~40 MPa 0.5 ;

[0023] (iv) The mass ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) is 10 / 90 to 95 / 5.

[0024] [2] According to the purification method of the liquid organic compound described in [1], wherein, in the above (i), [HSP-a] is 15~30 MPa. 0.5 .

[0025] [3] The method for purifying liquid organic compounds according to [1] or [2], wherein, in (ii) above, [HSP-b] is 25~50 MPa. 0.5 .

[0026] [4] A method for purifying a liquid organic compound according to any one of [1] to [3], wherein, in (iii) above, [HSP-b]-[HSP-a] is 3 to 35 MPa. 0.5 .

[0027] [5] A method for purifying a liquid organic compound according to any one of [1] to [4], wherein the monofunctional organic compound (A) is an alcohol having 1 to 5 carbon atoms, and the polyfunctional compound (B) is any one of a diol having 2 to 6 carbon atoms and water.

[0028] [6] A method for refining a liquid organic compound according to any one of [1] to [5], wherein the liquid organic compound (RM) is waste plastic decomposition oil.

[0029] Invention Effects

[0030] According to the present invention, a method can be provided to more effectively remove nitrogen-containing compounds and halogen-containing compounds from the above-mentioned liquid organic compounds (RM) through a simple method.

[0031] Furthermore, according to the present invention, it can be easily combined with conventional methods. Therefore, the present invention is a useful method for refining decomposed oil, for example, when the content of heteroatom compounds in the decomposed oil obtained by decomposing polymers such as waste plastics is low. Therefore, it is a useful method for obtaining ethylene, propylene, and aromatic compounds by introducing the obtained refined decomposed oil into a conventional naphtha cracker. Therefore, this method is powerful as a method for recycling, for example, waste plastics, and can be considered a useful technology from both industrial and environmental perspectives. Therefore, the present invention has significant industrial implications. Attached Figure Description

[0032] Figure 1 This is a chart summarizing the results of nitrogen compound extraction rates from Example 1, Comparative Example 1, and Comparative Example 2.

[0033] Figure 2 This is a chart summarizing the results of the extraction rates of chlorine compounds in Example 1, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0034] The present invention will now be described in further detail. It should be noted that, in this specification, the lower and upper limits of each numerical range can be arbitrarily combined.

[0035] <Methods for purifying liquid organic compounds>

[0036] The present invention is a method for purifying liquid organic compounds, comprising the following steps: contacting a liquid organic compound (RM) containing a nitrogen-containing compound, a halogen-containing compound, and a hydrocarbon compound, a monofunctional organic compound (A), and a polyfunctional compound (B), and then separating the monofunctional organic compound (A) and the polyfunctional compound (B).

[0037] The above method satisfies the requirements (i) to (iv) below.

[0038] (i) The above-mentioned monofunctional organic compound (A) is a compound containing carbon, hydrogen and oxygen, and its Hansen solubility parameter [HSP-a] is 15~35 MPa. 0.5 ;

[0039] (ii) The above-mentioned multifunctional compound (B) is a compound containing two or more elements selected from carbon, hydrogen and oxygen, and the Hansen solubility parameter [HSP-b] is 20~60 MPa. 0.5 ;

[0040] (iii) The value of [HSP-b]-[HSP-a] is 3~40 MPa 0.5 ;

[0041] (iv) The mass ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) is 10 / 90 to 95 / 5.

[0042] [Liquid Organic Compounds (RM)]

[0043] The liquid organic compound to be purified in the purification method of the present invention is not particularly limited as long as it is a liquid organic compound (RM) containing nitrogen-containing compounds, halogen-containing compounds, and hydrocarbon compounds. Preferably, it is an organic compound obtained by liquefying a carbon-containing polymer (resin, elastomer, etc.) through methods such as thermal decomposition.

[0044] The polymer described above is preferably waste material from plastic molded articles for various applications. The aforementioned plastic includes various plastics, such as any one of thermoplastic resins and thermosetting resins. Additionally, elastomers, waxes, oils, greases, etc., are also examples of the aforementioned polymer. Furthermore, so-called compositions comprising these various substances are, of course, also examples of the aforementioned polymer.

[0045] Examples of the aforementioned thermoplastic resins include polyolefins (PO) such as polyethylene (PE) and polypropylene (PP); styrene-based resins such as polystyrene (PS) and high-impact polystyrene (HIPS); copolymers of olefin monomers with small proportions of different monomers, such as ethylene-vinyl acetate copolymer (EVA); chlorine-containing resins such as polyvinyl chloride (PVC) and polyvinylidene chloride (PVDC); oxygen-containing resins such as acrylic resins such as polycarbonate, polymethyl acrylate, and polymethyl methacrylate resins; and nitrogen-containing resins such as various polyamides, polyimides, and ABS resins, with nylon (trademark name) as an example.

[0046] Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, alkyd resins, polyurethane (PU), epoxy resins, and thermosetting polyimides.

[0047] The above-mentioned polymers can be used alone or in combination with two or more of the above-mentioned thermoplastic resins and thermosetting resins.

[0048] Examples of compounds that can be categorized as elastomers, waxes, oils, and greases include the following.

[0049] Synthetic rubbers, for example, include ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), styrene-butadiene copolymer rubber (SBR), butadiene-acrylonitrile copolymer rubber (NBR), chloroprene rubber (CR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR), and their crosslinks (vulcanizates); and

[0050] Thermoplastic elastomers include, for example, partially cross-linked compositions of ethylene-propylene-nonconjugated diene copolymer rubber / polyethylene, styrene-butadiene copolymer hydrogenates, and synthetic hydrocarbon resins commonly referred to as "petroleum resins." Natural rubber can also be used.

[0051] In addition, examples include ethylene-based waxy polymers or grease-like polymers, and propylene-based waxy polymers or grease-like polymers, such as atactic polypropylene. Furthermore, liquid low-molecular-weight olefin polymers and mineral oils, which are components of engine oils, are also included. The aforementioned elastomers, waxes, oils, and greases can be used individually or in combination of two or more.

[0052] Alternatively, all of the above-mentioned polymers can be used in the form of a composition in which they are appropriately combined.

[0053] From the viewpoint of heat conduction and decomposition efficiency during thermal decomposition, it is preferable for a composition containing a high-melting-point component (so-called resin) and a low-melting-point component and / or a liquid component.

[0054] The polymers used as raw materials for the decomposed oils in this invention are particularly preferably so-called polyolefin complexes comprising polyolefins such as polyethylene and polypropylene, the aforementioned polyolefins, and elastomers.

[0055] On the other hand, it is common for the polymers used as feedstocks for oil decomposition to contain a mixture of nitrogen-containing polymers and / or chlorine-containing polymers. Examples of such components include polymers such as those described below (including "resin" and "rubber", also known as "crystalline polymer" and "amorphous or low-crystallinity polymer").

[0056] Nitrogen-containing polymers: polyamide resin (also known as "nylon"), ABS resin, butadiene-acrylonitrile copolymer rubber (NBR).

[0057] Chlorine-containing polymers: Polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), chloroprene rubber (CR)

[0058] The purification method of the present invention is highly effective for polymers containing the above-mentioned nitrogen-containing polymers and / or chlorine-containing polymers in a mixture of 0.1 to 20% by weight, preferably 1 to 10% by weight (based on total polymer content).

[0059] The polymer described above can be thermally decomposed using known methods to obtain the decomposed oil.

[0060] According to the inventors' research, such decomposed oils contain components believed to originate from polymers containing heteroatoms. For example, if they are nitrogen-containing compounds, in addition to amine compounds, they sometimes contain nitrogen-containing cyclic compounds such as pyridine and pyrrole, or compounds with cyano groups. Most of these nitrogen-containing compounds are alkaline and can therefore be removed by contact with inorganic acids, but for compounds with cyano groups, it is sometimes difficult to remove them using the methods described in Patent Documents 1 to 5.

[0061] The decomposition oil described above can be used directly in this invention. Furthermore, the liquid organic compound (RM) is preferably waste plastic decomposition oil. The decomposition oil may also be decomposition oil that has undergone hydrogenation treatment using a catalyst, as described later, or contact treatment with adsorbents such as metal oxides.

[0062] [Monofunctional organic compound (A)]

[0063] In the purification method of the liquid organic compound of the present invention, a monofunctional organic compound (A) is used. In this specification, a monofunctional organic compound refers to a compound having one functional group within one molecule. Furthermore, the monofunctional organic compound (A) of the present invention is characterized in that it is a compound containing carbon, hydrogen, and oxygen, and its Hansen solubility parameter [HSP-a] satisfies 15 to 35 MPa. 0.5 The lower limit of [HSP-a] is preferably 18 MPa. 0.5 More preferably 20 MPa 0.5 More preferably 22MPa 0.5 On the other hand, the upper limit of [HSP-a] is preferably 33 MPa. 0.5 More preferably 31 MPa 0.5 More preferably 30MPa 0.5 These upper and lower limits can be combined arbitrarily. It is believed that if the Hansen solubility parameter value is within the lower range mentioned above, it has a high affinity for the nitrogen-containing and halogen-containing compounds in the liquid organic compound (RM), and tends to easily dissolve them. Depending on the situation, it may also have the property of easily separating from the liquid organic compound (RM). Furthermore, it is believed that by combining with the polyfunctional compound (B) described later, the nitrogen-containing and halogen-containing compounds become difficult to return to the liquid organic compound (RM) (reverse dissolution).

[0064] Examples of monofunctional organic compounds (A) include monohydric alcohols, monoketones, monoaldehydes, monothiols, and monocarboxylic acids. Specifically, examples include monohydric alcohols such as methanol, ethanol, and propanol; monocarboxylic acids such as acetic acid and propionic acid; and monoketones such as acetone and methyl ethyl ketone. Among these, monohydric alcohols are preferred, alcohols with 1 to 5 carbon atoms are more preferred, methanol, ethanol, and isopropanol are even more preferred, methanol and ethanol are particularly preferred, and methanol is especially preferred.

[0065] [Multifunctional compound (B)]

[0066] In the purification method of the liquid organic compound of the present invention, a multifunctional compound (B) is used. In this specification, a multifunctional compound refers to a compound having multiple functional groups within a single molecule. Furthermore, the multifunctional compound (B) of the present invention is characterized in that it is a compound containing two or more elements selected from carbon, hydrogen, and oxygen, and its Hansen solubility parameter [HSP-b] satisfies a value of 20 to 60 MPa. 0.5 The lower limit value of [HSP-b] is preferably 23 MPa. 0.5 More preferably 25 MPa 0.5 Further preferred is 28MPa 0.5 On the other hand, the upper limit of the aforementioned [HSP-b] is preferably 57 MPa.0.5 More preferably 55 MPa 0.5 More preferably 53 MPa 0.5 These upper and lower limits can be combined arbitrarily. It is believed that if the Hansen solubility parameter value is within the lower range mentioned above, it has a relatively high affinity for nitrogen-containing and halogen-containing compounds in the aforementioned liquid organic compound (RM). Furthermore, it tends to have a high affinity for the aforementioned monofunctional organic compound (A), while showing a low affinity for the liquid organic compound (RM) as a whole. Therefore, it is believed that it is easily separated from the liquid organic compound (RM), and by combining it with the aforementioned monofunctional organic compound (A), it tends to easily dissolve the aforementioned nitrogen-containing and halogen-containing compounds from the liquid organic compound (RM) into the monofunctional organic compound (A) and the polyfunctional compound (B). It is believed that, depending on the circumstances, there is a tendency to prevent backflow (reverse dissolution) into the liquid organic compound (RM).

[0067] Examples of such compounds include water, polyols, polyketides, polyaldehydes, polythiols, and polycarboxylic acids.

[0068] Specifically, examples include water, polyols such as ethylene glycol, propylene glycol, and glycerol, polycarboxylic acids such as maleic acid and fumaric acid, and polycarboxylic acid esters such as maleate diester and fumarate diester. Among these, water and polyols are particularly preferred. As alcohols, they are diols with 2 to 6 carbon atoms, more preferably ethylene glycol and propylene glycol, and even more preferably ethylene glycol. Water is especially preferred as a multifunctional compound.

[0069] In this invention, water is defined as an inorganic compound containing two OH groups, belonging to a type of multifunctional compound (B).

[0070] [The relationship between monofunctional organic compounds (A) and polyfunctional organic compounds (B)]

[0071] The difference between the Hansen solubility parameters of the monofunctional organic compound (A) and the polyfunctional compound (B), "[HSP-b]-[HSP-a]", satisfies 3~40 MPa. 0.5 The upper limit of the above difference is preferably 35 MPa. 0.5 More preferably 30MPa 0.5 More preferably 25MPa 0.5 The lower limit of the above difference is preferably 4 MPa. 0.5 More preferably 6MPa 0.5 Further preferably 8MPa 0.5 10 MPa is particularly preferred. 0.5In this invention, it is believed that the difference in the above-mentioned Hansen solubility parameter values ​​being within a specific range has the following effects: it is easy to separate from the above-mentioned liquid organic compound (RM), and it is easy for nitrogen-containing compounds and halogen-containing compounds in the liquid organic compound (RM) to move to the above-mentioned monofunctional organic compound (A) and the above-mentioned polyfunctional compound (B), and it is difficult for them to return.

[0072] The ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) used may vary depending on the compound used. In this invention, the ratio of [monofunctional organic compound (A) / polyfunctional compound (B)] by mass is 10 / 90 to 95 / 5, preferably 13 / 87 to 92 / 8, more preferably 15 / 85 to 92 / 8, and even more preferably 15 / 85 to 90 / 10.

[0073] When the aforementioned multifunctional compound (B) is an organic compound, the ratio of [monofunctional organic compound (A) / multifunctional compound (B)] is preferably 13 / 87 to 80 / 20, more preferably 15 / 85 to 70 / 30, and even more preferably 15 / 85 to 60 / 40.

[0074] When the aforementioned multifunctional compound (B) is an inorganic compound, preferably water, the [monofunctional organic compound (A) / multifunctional compound (B)] is preferably 15 / 85 to 92 / 8, more preferably 30 / 70 to 92 / 8, and even more preferably 40 / 60 to 90 / 10.

[0075] The ratio of the sum of the aforementioned monofunctional organic compound (A) and the aforementioned polyfunctional compound (B) to the aforementioned liquid organic compound (RM) can be appropriately set according to the purpose and circumstances. Generally, the ratio is in the range of 1 / 99 to 99 / 1 by mass, preferably 5 / 95 to 95 / 5, more preferably 10 / 90 to 90 / 10, and even more preferably 20 / 80 to 80 / 20.

[0076] The monofunctional organic compound (A) and the polyfunctional organic compound (B) are typically mixed and then contacted with the liquid organic compound (RM). After stirring and shaking to ensure sufficient contact between the compounds, they are allowed to stand for phase separation. Following phase separation, the liquid organic compound layer is separated from the functional compound layer using conventional methods such as liquid-liquid separation to remove the lower layer and decantation to remove the upper layer.

[0077] In addition to the contact sequence described above, other methods may be employed, such as: contacting the polyfunctional compound (B) with the liquid organic compound (RM) followed by contacting the monofunctional organic compound (A); contacting the monofunctional organic compound (A) with the liquid organic compound (RM) followed by contacting the polyfunctional compound (B); or contacting all three components simultaneously. These methods can be appropriately selected based on the components used.

[0078] The temperature for performing the above operations can be appropriately selected considering the boiling point and melting point of each main component. A preferred temperature range is typically 10°C to 100°C. The lower limit of this temperature range is more preferably 15°C, further preferably 20°C, and particularly preferably 25°C. When phase separation is difficult, the preferred lower limit is 5°C, further preferably 8°C, and particularly preferably 10°C. On the other hand, from a safety perspective, the upper limit of this temperature range is more preferably 80°C, further preferably 70°C, and particularly preferably 60°C.

[0079] The above operation can be repeated as needed.

[0080] Furthermore, if the method of the present invention is used, as shown in the examples described later, cyanide-containing compounds (nitrile compounds, etc.) and pyrroles that are difficult to thermally decompose can also be effectively removed, thus making it suitable for obtaining thermally decomposable oils that can be used in conjunction with naphtha, etc.

[0081] The present invention is characterized by using the monofunctional organic compound (A) and the polyfunctional compound (B) in combination, while taking into account the Hansen solubility parameter value, as described above. As can be seen from the results of the embodiments described later, the method of the present invention, which uses both the monofunctional organic compound (A) and the polyfunctional compound (B), sometimes exhibits an unexpected tendency to show higher removal efficiency from liquid organic compounds (RM) containing nitrogen-containing compounds, halogen-containing compounds, and hydrocarbon compounds, compared to either the case where only the monofunctional organic compound (A) is contacted with the liquid organic compound (RM) or the case where only the polyfunctional compound (B) is contacted with the liquid organic compound (RM). The reason for this effect has not yet been determined. The inventors have made the following conjecture.

[0082] It is believed that the monofunctional organic compound (A) is essentially the main component from which nitrogen-containing and halogen-containing compounds are extracted from the liquid organic compound (RM). On the other hand, the polyfunctional compound (B) has a high Hansen solubility parameter value and is easily separated from the liquid organic compound (RM). Therefore, it may exhibit the effect of hindering the retrodissolution of nitrogen-containing and halogen-containing compounds dissolved in the monofunctional organic compound (A) into the liquid organic compound (RM). Furthermore, it is believed that it may act as an auxiliary agent for the migration of nitrogen-containing and halogen-containing compounds from the liquid organic compound (RM) to the monofunctional organic compound (A). Regarding this effect, it is believed that the Hansen solubility parameters of both the monofunctional organic compound (A) and the polyfunctional compound (B) are within a specific numerical range and a specific range of difference, thus exhibiting this unexpected effect.

[0083] The aforementioned liquid organic compound (RM) is preferably waste plastic decomposition oil. Furthermore, depending on the circumstances, it is sometimes preferable to treat the aforementioned waste plastic decomposition oil with a catalyst, as shown in the hydrogenation treatment method described below, or to treat it with an adsorbent, etc.

[0084] [Hydrogenation catalyst]

[0085] In the purification method of the present invention, the catalyst (hydrogenation catalyst) used for hydrogenating the above-mentioned liquid organic compound (RM) can be any known catalyst for hydrogenation. As a preferred example, a transition metal catalyst is used; as a more preferred example, a transition metal oxide catalyst used in the catalytic hydrogenation purification of petroleum is an example. Particularly preferred catalysts include molybdenum oxide, nickel oxide, and cobalt oxide. Multiple of these components can also be used in combination.

[0086] Furthermore, from the perspective of catalytic efficiency, it is preferable that these transition metal oxides are supported on the surface of a suitable particulate support composed of one or more selected from alumina, silica, silica-alumina, titanium dioxide, and zeolite as solid acids, and magnesium oxide as a solid base. That is, since the transition metal oxides that exert catalytic performance can be selectively distributed on the support surface, a specified amount of catalyst can be utilized as efficiently as possible.

[0087] In the purification method of the present invention, as a preferred method to exhibit the desired effect, examples include using the various transition metal oxide catalysts described above supported on a carrier composed of a solid acid and / or a solid base, and having the following properties. Examples of such carriers include those with an average particle size range of 50 to 50,000 μm, preferably 500 to 5,000 μm, and a specific surface area (based on the BET method) of 0.1 to 1,000 m². 2 / g, preferably 10~300m2 / g carrier.

[0088] [Hydrogenation Process]

[0089] In the refining method of the present invention, when performing the hydrogenation process, various reaction methods (apparatus) can be used, such as (tank-type) batch reaction or semi-batch reaction, continuous reaction, fixed bed, tubular reaction, fluidized bed or moving bed, etc.

[0090] The hydrogenation process described above is carried out at a reaction temperature of 150~800℃. The lower limit of this temperature range is preferably 170℃, more preferably 180℃, and the upper limit is preferably 600℃, more preferably 450℃. These upper and lower limits can be combined arbitrarily, but it is preferably carried out at 170~600℃, and more preferably at 180~450℃.

[0091] For example, when the above-mentioned hydrogenation process is carried out in a batch reaction manner, the following method can be used: relative to 1 kg of the above-mentioned decomposed oil, in the presence of 5 to 500 g, preferably 20 to 200 g, of the above-mentioned hydrogenation catalyst (transition metal oxide basis), and with hydrogen present at a partial pressure of 0.1 to 15 MPa, preferably 0.3 to 10 MPa, the mixture is heated at a reaction temperature of 150 to 800°C, preferably 170 to 600°C, more preferably 180 to 450°C for 0.5 to 10 hours, preferably 1 to 3 hours, to decompose nitrogen-containing compounds and / or chlorine-containing compounds.

[0092] When the above-mentioned hydrogenation process is carried out in a continuous reaction manner, an example method is to continuously supply the decomposed oil and hydrogen by filling the hydrogenation catalyst in a fixed bed. Regarding operating conditions, the reaction temperature is 150~800°C, preferably 170°C, more preferably 180°C, and preferably 600°C, more preferably 450°C. The preferred reaction pressure is 0.1~15 MPa, preferably 0.3 MPa, further preferably 0.4 MPa, and preferably 10 MPa, more preferably 8.0 MPa. The preferred weight space velocity (WHSV) is 0.1~100 h⁻¹. -1 The lower limit is more preferably 0.5h. -1 Further preferably 0.8h -1 1.0h is particularly preferred. -1 The upper limit is more preferably 50h -1 Further preferred is 10h -1 5h is particularly preferred -1 3h is particularly preferred -1(The “h” above represents hour.) The preferred hydrogen excess is 1 to 100 times, the lower limit is more preferably 2 times, further preferably 3 times, particularly preferably 5 times, the upper limit is more preferably 50 times, further preferably 30 times, and particularly preferably 20 times.

[0093] In the case of the continuous reaction method and the semi-batch method described above, the decomposed oil and hydrogen can of course be recycled to the hydrogenation catalyst.

[0094] If hydrogenation is performed under the conditions described above, components containing multiple bonds in the decomposed oil are effectively hydrogenated or decomposed. For example, in the case of unsaturated hydrocarbon compounds such as alkenes and dienes, saturated hydrocarbon compounds are generated, which is therefore preferred. In addition, compounds containing heteroatoms, such as nitrogen-containing compounds, are decomposed into volatile nitrogen-containing compounds and low-molecular-weight amine compounds. Such components can be easily removed by methods such as volatilizing them under low pressure.

[0095] On the other hand, according to the inventors' research, the hydrogenated decomposition oil also contains nitrogen-containing cyclic compounds with high molecular weights, such as pyrroles, but in most cases, it effectively reduces compounds containing carbon-nitrogen multiple bonds such as cyano groups.

[0096] [Processes involving contact with metal oxides]

[0097] The liquid organic compound (RM) used in this invention can be subjected to a contact process with metal oxides after the temperature is appropriately adjusted by methods such as cooling or heating. In this contact process, the decomposed oil is brought into contact with a solid component containing metal oxides. Such a method can be applied without limitation using known methods such as batch methods or continuous methods.

[0098] The above-described contact process is performed at a temperature below 150°C, preferably above room temperature and below 150°C. The lower limit of the temperature range is preferably 50°C, more preferably 60°C, further preferably 70°C, and particularly preferably 80°C. On the other hand, the upper limit is preferably 140°C, more preferably 130°C, further preferably 125°C, and particularly preferably 120°C.

[0099] When the aforementioned decomposed oil is brought into contact with the metal oxides described later at such a temperature, compounds containing heteroatoms can be effectively removed.

[0100] [Metal Oxides]

[0101] The aforementioned metal oxides can be used without limitation as long as they exhibit the effect of removing heteroatom-containing compounds such as nitrogen-containing compounds like amines and pyrroles. Examples of such metal oxides include alumina, aluminosilicates (represented by zeolites), iron oxide, zirconium oxide, and titanium oxide. Other examples include silicon dioxide, magnesium oxide, zinc oxide, copper oxide, calcium oxide, and sodium oxide. Among these, alumina, aluminosilicates (represented by zeolites), iron oxide, zirconium oxide, and titanium oxide are preferred, and alumina and aluminosilicates are further preferred examples. Alumina is particularly preferred. These metal oxides can be used individually or in combination. By combining these metal oxides, acidity, alkalinity, etc., can be adjusted, or by configuring multiple oxides in multiple layers, compositions suitable for various heteroatom-containing compounds can be achieved.

[0102] The aforementioned metal oxide can be in the form of a metal oxide or in the form of a composition containing other components. Other components can include, without limitation, known substances such as porous resins as so-called carriers. By using such carriers, it is possible, for example, to form a shape suitable for filling the aforementioned metal oxide into a column, increase the surface area of ​​the aforementioned metal oxide, and effectively improve its performance per unit weight.

[0103] Examples of commercially available products of metal oxides having the manner described above include molecular sieves, activated alumina, activated zirconium oxide, activated clay, kaolin, and activated clay.

[0104] In this invention, when considering the aforementioned metal oxides, in addition to their performance, molecular sieves, activated alumina, and activated clay are preferred examples from the perspectives of ease of acquisition and reusability based on calcination, etc. Particularly preferred examples are activated alumina and activated clay, with activated clay being particularly preferred. (It is known that activated clay contains iron oxide, magnesium oxide, etc., in addition to alumina and silicon dioxide.)

[0105] The ratio of the aforementioned decomposed oil to the aforementioned metal oxide (metal oxide ratio = decomposed oil / metal oxide) is preferably 2 to 1000 by weight. The lower limit is more preferably 4, further preferably 5, and particularly preferably 6. On the other hand, the upper limit is more preferably 500, further preferably 100, and particularly preferably 50.

[0106] The contact time between the decomposed oil and the metal oxide is preferably 1 minute to 24 hours. A lower limit of 5 minutes is more preferred, further preferred is 8 minutes, and particularly preferred is 10 minutes. On the other hand, an upper limit of 18 hours is more preferred, further preferred is 12 hours, and particularly preferred is 6 hours.

[0107] If there is too little of the aforementioned metal oxide or the contact time is too short, it may be insufficient to remove components containing heteroatoms. On the other hand, if there is too much of the aforementioned metal oxide or the contact time is too long, it tends to lead to high costs. In addition, depending on the conditions, the decomposed oil may sometimes deteriorate due to the aforementioned metal oxide.

[0108] As described above, the refining method of the present invention preferably involves performing a hydrogenation treatment step before the above-described contact step.

[0109] Provided the above conditions are met, the hydrogenation process and the contact process with the metal oxide can be performed multiple times. Furthermore, other processes may be included without impairing the effects of the present invention. For example, methods including known processes for removing heteroatom-containing compounds such as treatment with inorganic acids or steam treatment may be used.

[0110] As described above, it is believed that in the aforementioned hydrogenation process, compounds with multiple bonds, such as cyano groups (e.g., nitriles), which are presumed to be difficult to remove, are converted into pyrroles, amines, etc., through the hydrogenation reaction. Therefore, it is believed that by contacting the decomposed oil obtained in the aforementioned hydrogenation process with the aforementioned metal oxide, heteroatom-containing compounds, such as the aforementioned nitrogen compounds, may be adsorbed or decomposed and removed from the decomposed oil. In addition, when the aforementioned metal oxide has the properties of an adsorbent, it is generally believed that compounds with carbon-carbon multiple bonds, such as alkenes, are also easily adsorbed. Therefore, it is possible that the adsorption efficiency of the aforementioned heteroatom-containing compounds may be reduced. It is speculated that in the aforementioned hydrogenation process, since the content of such compounds with multiple bonds, such as alkenes, may be reduced, this is the main reason why the aforementioned heteroatom-containing compounds are easily adsorbed and removed.

[0111] The liquid organic compound obtained by the refining method of the present invention is in a state where nitrogen-containing compounds, halogen-containing compounds, etc., are reduced. Therefore, for example, if it is fed into a naphtha cracking process, it can be expected to be converted into unsaturated hydrocarbons such as ethylene, propylene, 1-butene, butadiene, isoprene, benzene, toluene, xylene, and styrene, which are useful as petrochemical feedstocks. Among these, ethylene and propylene are preferred in that they can be used as feedstocks for a wide range of products.

[0112] Polymers such as synthetic plastics are used in a wide range of applications, but most end up in landfills, incineration, or are simply discarded as waste at the end of their usefulness. There is room for improvement in terms of their efficient utilization. On the other hand, if the refining method of this invention is used, these polymers can be utilized as resources, just like crude oil.

[0113] <Methods for manufacturing refined liquid organic compounds>

[0114] One embodiment of the present invention is a method for manufacturing a refined liquid organic compound, comprising the following steps: contacting a liquid organic compound (RM) containing a nitrogen-containing compound, a halogen-containing compound, and a hydrocarbon compound, a monofunctional organic compound (A), and a polyfunctional compound (B), and then separating the monofunctional organic compound (A) and the polyfunctional compound (B).

[0115] The above method satisfies the requirements (i) to (iv) below.

[0116] (i) The above-mentioned monofunctional organic compound (A) is a compound containing carbon, hydrogen and oxygen, and its Hansen solubility parameter [HSP-a] is 15~35 MPa. 0.5 ;

[0117] (ii) The above-mentioned multifunctional compound (B) is a compound containing two or more elements selected from carbon, hydrogen and oxygen, and the Hansen solubility parameter [HSP-b] is 20~60 MPa. 0.5 ;

[0118] (iii) The value of [HSP-b]-[HSP-a] is 3~40 MPa 0.5 ;

[0119] (iv) The mass ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) is 10 / 90 to 95 / 5.

[0120] The meanings of the terms in the above manufacturing method are the same as those in the above <Refining Method of Liquid Organic Compounds>.

[0121] The refined product obtained by the refining method and manufacturing method of the present invention can, of course, be further processed by other refining methods. As preferred examples, the above-described hydrogenation treatment and contact treatment with an adsorbent are examples of preferred examples.

[0122] Example

[0123] The present invention will now be described in detail with reference to embodiments and comparative examples, but the present invention is not limited thereto.

[0124] [Waste plastic pyrolysis oil]

[0125] Prepare waste plastic pyrolysis oil (main component: hydrocarbon) with the composition shown in Table 1.

[0126] [Table 1]

[0127]

[0128] In addition, the above-mentioned waste plastic thermal decomposition oil was distilled, and the nitrogen and chlorine content in the recovered fractions were determined according to the boiling point. The cumulative results of the nitrogen and chlorine yields of each fraction relative to the raw material are shown in Table 2.

[0129] [Table 2]

[0130]

[0131] The results show that the above-mentioned waste plastic pyrolysis oils exhibit the following trends: they contain nitrogen compounds and chlorine compounds over a wide boiling point range, with nitrogen compounds being more abundant in the high-boiling-point region and chlorine compounds being more abundant in the low-boiling-point region.

[0132] In addition, analysis of the above-mentioned nitrogen compounds using methods such as gas chromatography revealed that they contained cyano compounds and pyrroles.

[0133] [Hansen solubility parameter (HSP) values ​​of the compounds used in the extraction]

[0134] Water (HSP: 47.8MPa 0.5 )

[0135] Methanol (MEOH) (HSP: 29.4 MPa) 0.5 )

[0136] Ethanol (ETOH) (HSP: 26.5 MPa) 0.5 )

[0137] Propylene glycol (PG) (HSP: 29.1 MPa) 0.5 )

[0138] Isopropanol (IPA) (HSP: 23.6 MPa) 0.5 )

[0139] The HSP of the mixture in the examples was calculated using conventional methods.

[0140] [Example 1]

[0141] [Solvent Extraction]

[0142] Extraction was performed using a methanol / water mixed solvent (methanol / water mass ratio of 16 / 84 to 88 / 12).

[0143] 10 ml of the above-mentioned waste plastic decomposition oil and 10 ml of methanol / water mixed solvent (methanol / water mass ratio of 16 / 84~88 / 12) as the extraction agent were added to the reaction apparatus and stirred for 1 minute at room temperature and pressure. After stirring, the mixture was allowed to stand for 1 hour, and the raffinate (equivalent to waste plastic thermal decomposition oil in this experiment) and the extract (equivalent to methanol-water solution in this experiment) were separated. The weight of the added raffinate and the weight of the recovered raffinate were measured, and the oil recovery rate (raffinate recovery amount / raffinate input amount) was calculated. The nitrogen and chlorine content of the raffinate were determined by chemiluminescence. The nitrogen and chlorine extraction rates from the decomposition oil were calculated by subtracting the amount of nitrogen and chlorine dissolved together with the oil when dissolved in the extractant. The results are shown in Table 3. The methanol concentration was 88% by weight (HSP: 31 MPa). 0.5 The highest extraction rates were observed (65% nitrogen extraction and 39% chlorine extraction) at that time.

[0144] [Table 3]

[0145]

[0146] [Example 2]

[0147] Extraction was performed using the above-mentioned pyrolysis oil and a mixed solvent of ethanol / water (ethanol / water mass ratio of 16 / 84 to 87 / 13) as the extraction agent, following the same method as in Example 1. The results are shown in Table 4. The ethanol concentration was 87% by weight (HSP: 29 MPa). 0.5 The highest extraction rates were observed (50% nitrogen extraction and 37% chlorine extraction) at that time.

[0148] [Table 4]

[0149]

[0150] [Example 3]

[0151] Extraction was performed using the above-mentioned thermally decomposed oil and a mixed solvent of isopropanol (IPA) / propylene glycol (PG) as the extraction agent (IPA / PG mass ratio of 16 / 84 to 34 / 66), following the same method as in Example 1. The results are shown in Table 5. The IPA concentration was 16% by weight (HSP: 28 MPa). 0.5 The highest nitrogen extraction rate (58%) was observed at an IPA concentration of 25% by weight (HSP: 27 MPa). 0.5 The highest chlorine extraction rate was shown when (chlorine extraction rate: 33%).

[0152] [Table 5]

[0153]

[0154] [Comparative Example 1]

[0155] The above-mentioned thermally decomposed oil and water as the extraction agent were used for extraction in the same manner as in Example 1. The results are shown in Table 6 (nitrogen extraction rate using water: 12%, chlorine extraction rate: 8%).

[0156] [Table 6]

[0157]

[0158] [Comparative Example 2]

[0159] The above-mentioned thermally decomposed oil and methanol as the extraction agent were used for extraction in the same manner as in Example 1. The results are shown in Table 6 (nitrogen extraction rate using methanol: 22%, chlorine extraction rate: 15%).

[0160] [Comparative Example 3]

[0161] The above-mentioned thermally decomposed oil and PG as the extraction agent were used for extraction in the same manner as in Example 1. The results are shown in Table 6 (nitrogen extraction rate using PG: 19%, chlorine extraction rate: 15%).

[0162] (Note: ETOH and IPA do not separate when mixed with decomposed oil.)

[0163] [Example 4]

[0164] A substance identical to the decomposition oil (nitrogen content 230 ppm, containing cyano compounds and pyrroles) obtained by thermal decomposition of waste plastics as described in Example 1 of Japanese Patent Application Publication No. 2024-061111 was prepared. The decomposition oil was treated with an extractant having a composition of MEOH / water = 65 / 35 (mass ratio) using the same method as in Example 1. This treatment was repeated four times (a total of five treatments). Otherwise, extraction was performed using the same method as in Example 1. The nitrogen content of the resulting treated solution was 10 ppm.

[0165] [Comparative Example 4]

[0166] [Metal Oxide Contact Treatment]

[0167] 10 ml of the above-mentioned pyrolysis oil (nitrogen content 230 ppm) and 0.7 g of activated clay prepared by Dongxin Chemical were added and stirred at 100°C and normal pressure for 30 minutes. Then, the activated clay was filtered out using conventional methods. The resulting pyrolysis oil (filtrate) had a nitrogen content of 110 ppm, making it difficult to extract cyanide compounds.

[0168] The above results demonstrate that the method of the present invention also has excellent removal capabilities for cyanide-containing compounds and pyrroles.

[0169] As described above, the following unexpected result was obtained: in the case of a combination of monofunctional organic compounds (methanol was used in Example 1) and polyfunctional compounds (water was used in Example 1), the extraction rates of nitrogen-containing and chlorine-containing compounds from the decomposition oil were higher compared to either monofunctional organic compounds alone or polyfunctional organic compounds alone. This is believed to be because the polyfunctional compound (B), which is easily separated from the decomposition oil, exhibits an effect that hinders the reverse dissolution of nitrogen-containing and chlorine-containing compounds dissolved in the monofunctional organic compound (A) in the decomposition oil. This unexpected result is attributed to the Hansen solubility parameters of both monofunctional organic compound (A) and polyfunctional compound (B) falling within a specific numerical range and a specific range of differences.

Claims

1. A method for purifying a liquid organic compound, comprising the following steps: contacting a liquid organic compound (RM) containing a nitrogen-containing compound, a halogen-containing compound, and a hydrocarbon compound, a monofunctional organic compound (A), and a polyfunctional compound (B), followed by separating the monofunctional organic compound (A) and the polyfunctional compound (B). The method satisfies the following requirements (i) to (iv). (i) The monofunctional organic compound (A) is a compound containing carbon, hydrogen, and oxygen, and has a Hansen solubility parameter [HSP-a] of 15–35 MPa. 0.5 , (ii) The multifunctional compound (B) is a compound containing two or more elements selected from carbon, hydrogen, and oxygen, and the Hansen solubility parameter [HSP-b] is 20~60 MPa. 0.5 , (iii) The value of [HSP-b]-[HSP-a] is 3~40 MPa 0.5 , (iv) The mass ratio of the monofunctional organic compound (A) to the polyfunctional compound (B) is 10 / 90 to 95 / 5.

2. The method for purifying liquid organic compounds according to claim 1, wherein, In (i), [HSP-a] is 15~30 MPa. 0.5 .

3. The method for purifying liquid organic compounds according to claim 1, wherein, In (ii), [HSP-b] is 25~50 MPa. 0.5 .

4. The method for purifying liquid organic compounds according to claim 1, wherein, In (iii), [HSP-b]-[HSP-a] is 3~35 MPa. 0.5 .

5. The method for purifying liquid organic compounds according to claim 1, wherein, The monofunctional organic compound (A) is an alcohol having 1 to 5 carbon atoms, and the polyfunctional compound (B) is any one selected from diols having 2 to 6 carbon atoms and water.

6. The method for purifying liquid organic compounds according to claim 1, wherein, The liquid organic compound (RM) is waste plastic decomposition oil.

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