Method for producing cumene, phenol, and α-methylstyrene

Abstract

To provide a method for producing a liquid containing industrially useful cumene, phenol, and α-methylstyrene, which can inexpensively and efficiently recover cumene, phenol, and α-methylstyrene, regarded as industrially useful substances, from a liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol (for example, phenol distillation residue).SOLUTION: A liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol is thermally decomposed at 200-350°C in the presence of a catalytic component of at least one element selected from the group consisting of iron and zinc in a metallic or ionic state, to produce a liquid (B) having higher contents of cumene, phenol, and α-methylstyrene than the liquid (A).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing cumene, phenol, and α-methylstyrene, and more particularly to a method for producing a liquid containing enhanced amounts of useful substances such as cumene, phenol, and α-methylstyrene from a raw material liquid such as a reaction mixture containing by-products produced in a process for producing phenol and acetone by the oxidation of cumene with oxygen. [Background technology]

[0002] Phenol is a compound widely used as a synthetic intermediate for synthetic resins, surfactants, pharmaceuticals, etc. Various methods are known for producing phenol, but the most widely used is the cumene process, in which cumene is oxidized with oxygen to synthesize cumene hydroperoxide, which is then decomposed with an acid to produce phenol and acetone.

[0003] When attempting to produce phenol by the cumene process involving the oxygen oxidation of cumene as described above, the production of by-products such as dimethylphenylcarbinol, acetophenone, α-methylstyrene, α-methylstyrene dimer, and cumylphenol is unavoidable, and the reaction mixture obtained after the reaction contains these by-products in addition to phenol and acetone. Therefore, the distillation residue obtained after separating cumene, phenol, and acetone from such a reaction mixture by distillation (hereinafter sometimes referred to as "phenol distillation residue") contains by-products such as dimethylphenylcarbinol, α-methylstyrene dimer, and cumylphenol. Converting these by-products into useful substances and recovering them is extremely important for reducing the cost of phenol production by the cumene process.

[0004] Conventionally, useful substances such as cumene, phenol, and α-methylstyrene have been recovered from the phenol distillation residue by pyrolysis of the phenol distillation residue followed by distillation, etc. However, the conventional method of pyrolyzing the phenol distillation residue has the problems that it takes a long time to complete the decomposition and that the recovery rates of cumene, phenol, and α-methylstyrene are low.

[0005] In order to solve these problems, Patent Document 1 discloses a method for recovering useful substances such as cumene, phenol, and α-methylstyrene from a phenol distillation residue produced by a cumene process, which method comprises thermally decomposing the phenol distillation residue in the presence of an alumina catalyst such as γ-alumina or a silica-alumina catalyst such as silica-alumina, acid clay, or synthetic zeolite, or in the coexistence of such a catalyst with an acid.

[0006] Patent Document 2 discloses a method for recovering useful substances such as cumene, phenol, and α-methylstyrene from a phenol distillation residue, which comprises thermally decomposing the phenol distillation residue in the presence of a metal compound catalyst such as a metal chloride or metal oxide containing at least one element selected from Mg, Al, Si, Zn, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu and having a particle size of 0.02 to 10 μm in the phenol distillation residue in an amount of 10 to 1,000 ppm by mass. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 59-36892 [Patent Document 2] Patent No. 254307 Summary of the Invention [Problem to be solved by the invention]

[0008] According to the examples specifically disclosed in Patent Document 1, the silica-alumina catalyst used has a large particle size and an Al2O3 to SiO2 ratio of 10:90 to 50:50, and the reaction temperature is ultimately increased to 340 to 350° C. Furthermore, the recovery rate of α-methylstyrene from dimethylphenylcarbinol, α-methylstyrene dimer, ortho-cumylphenol, and para-cumylphenol was high at 70 to 100%, but the recovery rate of phenol was only 3 to 30%.

[0009] Furthermore, according to the examples disclosed in Patent Document 2, zinc chloride and iron chloride are used as the metal compounds of the catalyst. The phenol yield in these examples is improved compared to the comparative examples, but is at most 85 mol % and the calculation method is not disclosed. For this reason, it would be desirable to further increase the phenol yield from distillation residue.

[0010] That is, conventional production methods have room for improvement in terms of industrially recovering useful substances such as cumene, phenol, and α-methylstyrene from the phenol distillation residue.

[0011] The present invention has been made in view of the above circumstances, and provides a method for producing an industrially useful liquid containing cumene, phenol, and α-methylstyrene, which can recover industrially useful substances, cumene, phenol, and α-methylstyrene, from a liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol (for example, phenol distillation residue), at low cost and with high efficiency. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have found a method for efficiently obtaining a liquid containing useful substances such as cumene, phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol at a high content, i.e., a method for recovering useful substances, by thermally decomposing a liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, which is typically a phenol distillation residue obtained by oxidizing cumene with oxygen to synthesize cumene hydroperoxide and then acidically decomposing the cumene hydroperoxide to obtain a reaction mixture, and then separating phenol, acetone, and unreacted cumene from the resulting reaction mixture, in the presence of a catalyst component in the metallic or metallic ion state of elemental iron or zinc.

[0013] That is, according to the present invention, as shown below, there is provided a method for industrially recovering a liquid (B) having a high content of useful substances such as cumene, phenol, and α-methylstyrene from a liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, such as a phenol distillation residue.

[0014] That is, the present invention includes the following items [1] to

[10] . [1] A method for producing a liquid (B) having a higher content of cumene, phenol, and α-methylstyrene than that of the liquid (A), by thermally decomposing a liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol at 200 to 350°C in the presence of a catalyst component in the metal or metal ion state of at least one element selected from the group consisting of iron and zinc. [2] The method for producing the liquid (B) according to [1], wherein the catalyst component contains iron metal, and the content of iron metal in the catalyst component is 89.5 to 100 mass %. [3] The method for producing the liquid (B) according to [1], wherein the catalyst component contains zinc metal, and the content of zinc metal in the catalyst component is 95.0 to 100 mass %. [4] The method for producing the liquid (B) according to any one of [1] to [3], wherein the catalyst component is a particulate catalyst component. [5] A liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol; contacting the solution with at least one solid selected from the group consisting of iron compounds and zinc compounds; A method for producing a reaction solution (α) containing a liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, and iron and / or zinc. [6] The method according to [5], wherein the iron compound has an iron metal content of 89.5 to 100 mass %. [7] The method for producing the reaction solution (α) according to [5], wherein the contact of the liquid (A) with at least one solid selected from the group consisting of iron compounds and zinc compounds is carried out using a flow-through fixed bed of at least one solid selected from the group consisting of iron compounds and zinc compounds. [8] The method for producing the reaction solution (α) according to [5], wherein the liquid (A) is contacted with at least one solid selected from the group consisting of iron compounds and zinc compounds in a batch reaction tank. [9] The method for producing the reaction solution (α) according to [5], wherein the contact is carried out at 100°C or higher and lower than 200°C.

[10] The method for producing the reaction solution (α) according to [5], wherein the iron compound is iron metal. [Effects of the Invention]

[0015] According to the present invention, a method for industrially recovering useful substances from a liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, which is typically a phenol distillation residue obtained by distilling and separating cumene, phenol, and acetone from a reaction mixture obtained by oxygen oxidation of cumene to synthesize cumene hydroperoxide, and then acidolysis of this cumene, can be provided. For example, by using inexpensive iron metal and zinc metal as catalysts, cumene, phenol, and α-methylstyrene can be recovered from the phenol distillation residue with high recovery rates. This can significantly contribute to reducing the cost of phenol production. DETAILED DESCRIPTION OF THE INVENTION

[0016] <Method for producing liquid (B) from liquid (A)> Hereinafter, a method (hereinafter sometimes referred to as a "recovery method") according to the present invention for producing a liquid (B) having a high content of useful substances including cumene, phenol, and α-methylstyrene from a liquid (A) (e.g., phenol distillation residue) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, such as phenol distillation residue, will be specifically described.

[0017] As mentioned above, a typical example of the liquid (A) of the present invention is phenol distillation residue produced by the cumene process, but this is not limiting, and any liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol can be used as the liquid (A) without any problems. Other components that may be contained include cumene, α-methylstyrene, etc. Of course, the liquid (A) may also contain heavy substances. Furthermore, the cumylphenol may be any isomer, such as the para-isomer or the ortho-isomer.

[0018] As shown in the following formula (1), cumene is oxidized with oxygen to synthesize cumene hydroperoxide, which is then acidically decomposed to produce phenol and acetone. The resulting reaction mixture is distilled to separate cumene, phenol, and acetone. The resulting phenol distillation residue is typically a liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, cumylphenol, and the like. It is known that, for example, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol can be converted into cumene, phenol, and α-methylstyrene by thermally decomposing a liquid (A) typified by such phenol distillation residue. By applying the production method of the present invention, the above-mentioned phenol, cumene, and α-methylstyrene can be recovered with high efficiency even from the phenol distillation residue.

[0019] [ka]

[0020] More specifically, the phenol distillation residue, which is a typical example of the liquid (A), usually contains, as by-products, dimethylphenylcarbinol represented by the following formula, α-methylstyrene, an α-methylstyrene dimer having an olefin structure, ortho-cumylphenol, para-cumylphenol, acetophenone, or other high-boiling products.

[0021] [ka]

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] The method of the present invention for recovering a liquid (B) containing useful substances from the liquid (A) (e.g., phenol distillation residue) is characterized in that the liquid (A) is thermally decomposed at 200 to 350°C in the presence of a catalyst component in the metal or metal ion state of at least one element selected from the group consisting of iron and zinc.

[0027] The catalyst component is characterized by containing iron metal, zinc metal, or iron or zinc ions. When the iron or zinc is in a metallic state, i.e., solid state, its content is 20% by mass or more. The iron metal or zinc metal may be in the form of a pure metal or an alloy with other elements. When the catalyst contains the above elements as metals, if the catalyst is iron metal, the iron metal content is preferably 89.5 to 100% by mass, and if the catalyst is zinc metal, the zinc metal content is preferably 95% to 100% by mass, and more preferably 97.0% to 100% by mass. When the catalyst is an iron alloy, the lower limit of the iron content is preferably 90% by mass, more preferably 92% by mass, and even more preferably 93% by mass.

[0028] As described above, the iron metal, including the alloy used as the catalyst, preferably has an iron content of 89.5 to 100 mass%. Trace amounts of carbon, silicon, manganese, phosphorus, and sulfur may be included as other components. An industrially advantageous example of such an alloy material is carbon steel, which is easy to process, inexpensive, and commonly available, and has a carbon content of 0.02 to 2.14 mass%. The shape of the iron metal-containing catalyst component may be any shape as long as it efficiently contacts with liquid (A) during the reaction, but a particulate shape is preferred from the viewpoint of surface area, etc. More specifically, powder, spheres, plates, shavings, etc. are preferred. From an industrial perspective, prior to the thermal decomposition step, it is desirable to dissolve part or all of the iron metal-containing catalyst component in liquid (A) (e.g., phenol distillation residue), more preferably homogenize it, and then carry out the thermal decomposition reaction. In this case, when the iron metal solution concentration is 1 to 5,000 mass ppm, preferably 10 to 500 mass ppm relative to the liquid (A), the useful liquid (B) tends to be recovered at a high recovery rate.

[0029] The zinc metal used as the catalyst preferably has a zinc content, including alloy forms, of 95% to 100% by mass, more preferably 97.0% to 100% by mass. Its shape may be any shape as long as it efficiently contacts with liquid (A) during the reaction; however, from the viewpoint of surface area, a particulate form is preferred, and more specifically, a powder or flower-like form is desirable. Industrially, prior to the thermal decomposition step, it is desirable to dissolve part or all of the catalyst containing zinc metal in liquid (A) (e.g., phenol distillation residue), more preferably homogenize it, and then carry out the thermal decomposition reaction. The dissolved zinc metal concentration in this case should be 1 to 5,000 ppm by mass, preferably 10 to 500 ppm by mass, relative to liquid (A), allowing for a high recovery rate of the useful product, liquid (B).

[0030] The content of each metal in the catalyst can be calculated by a known method. A typical method is inductively coupled plasma atomic emission spectroscopy (ICP-AES), which is used in the present invention. Examples of measuring devices include the ICPS-8100 (product name) manufactured by Shimadzu Corporation.

[0031] It is obvious that the dissolved iron and zinc are dissolved in the form of ions in principle.

[0032] When the catalyst component of the present invention is solid, it may be in the form of a composition with other components such as a known carrier. In such a case, the content of the metal component contained in the catalyst component is preferably 20% by mass or more, as described above. It is more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The carrier may be a known component such as a metal oxide, a metal chloride, or a polymer of an organic compound. Of course, it is preferable that the other components do not dissolve in the liquid (A).

[0033] In the present invention, the mass ratio of the liquid (A) to the catalyst component is preferably 1 to 1 × 10 6A more preferred lower limit is 5, even more preferred is 8, and particularly preferred is 10. On the other hand, a more preferred upper limit is 100,000, even more preferred is 50,000, and particularly preferred is 20,000.

[0034] As described above, the inventors speculate that the catalytic component containing iron or zinc dissolves in liquid (A) and becomes ionic, thereby exerting its catalytic effect. From the perspective of dissolution, the iron or zinc component, which is the catalyst component specified in the present invention, is an important point. It is conceivable that a metallic reactor containing iron could function as a catalyst in the production of phenol by the so-called cumene process. However, because an acid catalyst is used to decompose cumene peroxide and the product phenol is acidic, the reactor is made of acid-resistant materials such as glass coating or acid-resistant stainless steel alloy. Therefore, iron does not substantially elute as ions, and therefore it cannot be considered a catalytic component. Furthermore, because the reactor's shape limits the area of ​​contact with liquid (A), even if metal elution did occur, its catalytic function would not be apparent.

[0035] The above embodiment will be explained in more detail. Iron metal and zinc metal ionize upon reaction with phenol, respectively, and this ionization can be considered to contribute as a catalyst to convert phenol by-products into desirable compounds, such as raw materials for phenol production. The method of generating such ions is not limited to contacting iron metal and zinc metal with phenol during the phenol production process. For example, a suitable method involves contacting iron metal and zinc metal with various acids, preferably in an organic compound liquid environment, in a separate reactor to generate metal ions, and then introducing this reaction solution into the phenol production process. Examples of acidic compounds that can be reacted with the iron metal and zinc metal include organic compounds such as aromatic hydroxy compounds such as the above-mentioned phenol; aliphatic monocarboxylic acid compounds or aliphatic polycarboxylic acid compounds such as formic acid, acetic acid, propionic acid, and butanoic acid; aromatic carboxylic acid compounds such as benzoic acid and various phthalic acids; and sulfonic acid compounds such as benzenesulfonic acid. From the standpoint of acidity, such organic compounds preferably have 1 to 20 carbon atoms, more preferably 1 to 15, even more preferably 1 to 10, and particularly preferably 1 to 8 carbon atoms.

[0036] In addition to the organic acid compounds described above, methods for obtaining metal ions using inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid can also be used. Since the production of phenols and the like is generally carried out in a system essentially consisting mainly of organic compounds, it is preferable that the metal ions prepared by the above methods be soluble in the organic compound system. From this perspective, a method using an oxygen-containing acidic compound is preferred as a method for obtaining the metal ions. More specifically, a method selected from the method using the organic acid described above and the method using an aromatic hydroxy compound is a preferred example.

[0037] <Method for producing reaction solution (α)> As described above, in the present invention, to obtain the liquid (B), it is preferable to produce a reaction solution (α) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, as well as the iron compound and / or zinc compound. That is, in this embodiment, the iron compound and / or zinc compound is dissolved in the liquid (A) (in the present invention, the iron compound includes iron metal, and the zinc compound includes zinc metal). The iron compound and / or zinc compound dissolved in the liquid (A) is not particularly limited as long as it is a compound that is easily soluble in the liquid (A), but iron metal, an alloy containing iron, zinc metal, or an alloy containing zinc metal is preferred. As described above, the iron compound preferably has an iron metal content of 89.5 to 100 mass%, more preferably 95 to 100 mass%. Iron metal is particularly preferred. The iron metal content in the iron compound can be measured by known elemental analysis. For example, after cutting a part of the sample and dissolving it in an inorganic acid such as sulfuric acid, the sample can be analyzed by the ICP-AES method, or by ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry). Other methods include flame AAS, frameless AAS (Frame-Less Atomic Absorption Spectrometry), and ICP-MS (Inductively Coupled Plasma Mass Spectrometry (PSP) can be used depending on the purpose. When using commercially available stainless steel materials, if the composition is determined by a standard, the numerical values ​​can be used.

[0038] The method for producing the reaction solution (α) is a method of contacting a liquid (A) (e.g., a phenol distillation residue) with the iron compound or zinc compound. The method for dissolving the iron compound or zinc compound in the liquid (A) by such contact may be carried out by either a batch system or a flow system. In the former case, a method using a batch system reaction vessel is preferred. In the latter case, a method using a fixed bed of the iron compound or zinc compound is preferred.

[0039] When the reaction is carried out batchwise, the solubility of the iron compound or zinc compound can be adjusted by the ratio of the iron compound or zinc compound to the liquid (A), the contact temperature, and the contact time. In the case of a flow-through system, the solution concentration of the iron or zinc compound can be adjusted by the weight of the iron or zinc compound, the flow rate of the liquid (A), the residence time, and the contact temperature. Of course, the specific surface area of ​​the iron or zinc compound (which is affected by the shape and size of the solid) is also an important factor.

[0040] In the method for producing the reaction solution (α) of the present invention, the concentration adjusting factor can be adjusted as desired, but the temperature is preferably 100°C or higher and lower than 200°C, more preferably 130°C or higher and 180°C or lower.

[0041] The dissolution reaction of the liquid (A) can be carried out under any of reduced pressure, normal pressure, and increased pressure conditions, but is usually carried out under normal pressure in the batch system and under increased pressure in the flow system.

[0042] In the case of a batch reaction, the dissolution time is usually 2 to 15 hours, and preferably about 3 to 10 hours. In the case of a flow reaction, the residence time is 0.02 to 0.25 hours, and preferably 0.2 to 0.25 hours.

[0043] The liquid (A) containing the metal components obtained in the dissolution reaction can be used directly in the next thermal decomposition reaction. It may also be used in the next thermal decomposition reaction after a filtration step using a filter or the like. In the case of a batch reaction, the insoluble components may be allowed to settle and separated, and the supernatant liquid may be used in the next thermal decomposition reaction.

[0044] (thermal decomposition reaction) The thermal decomposition reaction of the liquid (A) with the catalyst component, that is, the thermal decomposition reaction using the reaction solution (α), may be carried out either batchwise or through-flow.

[0045] In the method for producing liquid (B) of the present invention, the thermal decomposition reaction is carried out in a temperature range of 200 to 350° C. The temperature range is more preferably 250 to 310° C. Under such temperature conditions, useful substances (liquid (B)) such as cumene, phenol, and α-methylstyrene can be recovered with high efficiency.

[0046] The thermal decomposition reaction of the liquid (A) can be carried out under any of reduced pressure, normal pressure, and increased pressure, but is usually carried out under normal pressure.

[0047] The reaction time varies greatly depending on the reaction temperature in both batch and flow systems. In the case of a batch system, it is usually 2 to 15 hours, preferably about 3 to 10 hours. In the case of a flow system, the residence time is 3 to 30 hours, preferably 10 to 20 hours.

[0048] In this way, when a liquid (A), such as a phenol distillation residue, is reacted in the presence of a catalyst component in the metal or metal ion state of at least one element selected from the group consisting of iron and zinc at a temperature of 200 to 350°C, preferably 250 to 310°C, the dimethylphenylcarbinol and α-methylstyrene dimer contained in the distillation residue are converted to α-methylstyrene with high selectivity. Specifically, the dimethylphenylcarbinol is dehydrated to α-methylstyrene (Equation 2), and the α-methylstyrene dimer is depolymerized to α-methylstyrene (Equation 3). Furthermore, ortho-cumylphenol and para-cumylphenol are decomposed to α-methylstyrene and phenol (Equation 4). The hydrogen generated in the reaction system hydrogenates the α-methylstyrene to produce cumene.

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. The thermal cracking efficiency, cumene recovery rate, phenol recovery rate, and α-methylstyrene recovery rate described in the examples and comparative examples are defined as follows.

[0054] Thermal decomposition efficiency (mass%) = 100 × ([Cum] + [PH] + [αMS]) / ([Cumf] + [PHf] + [αMSf] + [DPCf] + [CPHf] + [αMS2f]) Cumene recovery rate (mol%) = 100 × <cum> / ( <cumf> + <dpcf> + <cphf>+2×<αMS2f>) Phenol recovery rate (mol%) = 100 x <ph> / ( <phf> + <cphf>) α-Methylstyrene recovery rate (mol%) = 100 × <αMS> / (<αMSf> + <dpcf> + <cphf>+2×<αMS2f>)

[0055] The symbols in the above formula are defined as follows: [Cum]: Mass of cumene in the distillate [PH]: Mass of phenol in the distillate [αMS]: Mass of α-methylstyrene in the distillate [Cumf]: Mass of cumene in the charged phenol distillation residue [PHf]: Mass of phenol in the charged phenol distillation residue [αMSf]: Mass of α-methylstyrene in the charged phenol distillation residue [DPCf]: Mass of dimethylphenylcarbinol in the charged phenol distillation residue [CPHf]: Mass of cumylphenol in the charged phenol distillation residue [αMS2f]: Mass of α-methylstyrene dimer in the charged phenol distillation residue <cum>: Amount of cumene moles in the distillate <ph>: Molar amount of phenol in the distillate <αMS>: Molar amount of α-methylstyrene in the distillate <cumf>: Molar amount in the charged phenol distillation residue <phf>: Molar amount in the charged phenol distillation residue <αMSf>: Molar amount of α-methylstyrene in the charged phenol distillation residue <dpcf>: Molar amount of dimethylphenylcarbinol in the charged phenol distillation residue <cphf>: Molar amount of cumylphenol in the charged phenol distillation residue <αMS2f>: Molar amount of α-methylstyrene dimer in the charged phenol distillation residue

[0056] (Iron materials used: components other than iron) SS400: Carbon content 0.02~2.14% by mass SUS316L: Carbon content: 0.03% by mass or less Silicon content: 1.00% by mass or less Manganese content: 2.00% by mass or less Phosphorus content: 0.045% by mass or less Sulfur content: 0.03% by mass or less Nickel content: 12-15% by mass Chromium content: 16-18% by mass Molybuten content: 2~3% by mass

[0057] (Method for measuring iron concentration) In the examples, the iron concentration in the phenol distillation residue was determined by a conventional method using an ICP-AES measuring device.

[0058] The phenol distillation residue used in the examples and comparative examples has the following composition, but the production method of the present invention can be applied to any liquid containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, such as a phenol distillation residue obtained by the cumene process, even if it has a composition other than this.

[0059] Phenol distillation residue composition: acetophenone 15 to 30 mass%, dimethylphenylcarbinol 1 to 10 mass%, phenol 15 to 25 mass%, paracumylphenol 10 to 20 mass%, α-methylstyrene dimer 10 to 20 mass%, orthocumylphenol 1 to 10 mass%, and heavy fractions

[0060] [Example 1] A 300 mL five-neck flask equipped with a stirring device with a stirring blade made of SUS316L, a condenser connected to a distillate receiver, a nitrogen inlet, and a temperature detector was charged with 180.0 g of phenol distillation residue obtained by the cumene process and 9.0 g of iron powder. The batch reaction was gradually heated with stirring, and low-boiling substances were distilled off. The final reaction temperature was raised to 300°C and maintained at this temperature for 3 hours. The resulting distillate was analyzed by gas chromatography. Cumene, α-methylstyrene, and phenol, which were decomposition products of the initial feed (dimethylphenylcarbinol, α-methylstyrene dimer, para-cumylphenol, and ortho-cumylphenol), were obtained with a thermal decomposition efficiency of 77%, a cumene recovery of 18%, a phenol recovery of 83%, and a α-methylstyrene recovery of 65%. (Cumene is formed by hydrogenation of α-methylstyrene with hydrogen generated in the reaction system.)

[0061] [Example 2] Using the same method as in Example 1, 180.0 g of phenol distillation residue and 9.0 g of shavings obtained when a plate of carbon steel SS400 was drilled were charged. The same operations as in Example 1 were carried out, and the resulting distillate was analyzed by gas chromatography. As a result, cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 85%, a cumene recovery rate of 21%, a phenol recovery rate of 89%, and an α-methylstyrene recovery rate of 65%.

[0062] [Example 3] Using the same method as in Example 1, 180.5 g of phenol distillation residue and 18.1 g of zinc powder were charged. The same operation as in Example 1 was repeated, and the resulting distillate was analyzed by gas chromatography. The results showed that cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 85%, a cumene recovery rate of 15%, a phenol recovery rate of 94%, and an α-methylstyrene recovery rate of 68%.

[0063] [Example 4] 180.1 g of phenol distillation residue and 9.5 g of zinc oxide were charged in the same manner as in Example 1. The same operations as in Example 1 were carried out, and the obtained distillate was analyzed by gas chromatography. As a result, cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 81%, a cumene recovery rate of 15%, a phenol recovery rate of 90%, and an α-methylstyrene recovery rate of 63%.

[0064] [Comparative Example 1] Using the same apparatus as in Example 1, 180.4 g of phenol distillation residue was charged, but no metal compound was charged. The same operation as in Example 1 was carried out, and the obtained distillate was analyzed by gas chromatography. The results showed that cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 65%, a cumene recovery rate of 16%, a phenol recovery rate of 79%, and an α-methylstyrene recovery rate of 40%.

[0065] Comparative Example 2 In an apparatus similar to that of Example 1, 180.1 g of phenol distillation residue and 9.1 g of shavings obtained when a plate-shaped SUS316L was drilled were charged. The same operation as in Example 1 was carried out, and the obtained distillate was analyzed by gas chromatography. As a result, cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 64%, a cumene recovery rate of 17%, a phenol recovery rate of 82%, and an α-methylstyrene recovery rate of 36%. The results of Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1 below.

[0066] [Table 1]

[0067] [Example 5] 3,603 g of phenol distillation residue and 362 g of shavings obtained when a plate of carbon steel SS400 was cut with a drill were added to a 5 L three-neck flask equipped with a stirrer, a condenser, a nitrogen inlet, and a temperature detector, and the mixture was stirred at 130°C for 44 hours. The shavings were then filtered to produce a phenol distillation residue solution with an iron concentration of 3,200 ppm by mass.

[0068] [Example 6] A 600 mL SUS316L reactor equipped with a stirring device with a stirring blade, a condenser connected to a receiver for the distillate, a nitrogen inlet, a temperature detector, and a reaction liquid outlet was continuously pumped into the reactor. Low-boiling compounds, including cumene, α-methylstyrene, and phenol, were continuously distilled off. Simultaneously, the reaction liquid was continuously withdrawn to maintain a constant liquid level. A flow test was conducted for over 80 hours at a reaction temperature of 300 °C and a residence time of 16.5 hours. The resulting distillate was analyzed by gas chromatography. Cumene, α-methylstyrene, and phenol were obtained with a pyrolysis efficiency of 82%, a cumene recovery of 49%, a phenol recovery of 83%, and an α-methylstyrene recovery of 31%.

[0069] [Example 7] Using the same apparatus as in Example 6, a flow reaction was carried out in the same manner as in Example 6, using phenol distillation residue with an iron concentration adjusted to 260 ppm by mass. The obtained distillate was analyzed by gas chromatography. The results showed that cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 86%, a cumene recovery rate of 54%, a phenol recovery rate of 87%, and an α-methylstyrene recovery rate of 30%.

[0070] [Example 8] Using the same apparatus as in Example 6, a flow reaction was carried out in the same manner as in Example 6, using phenol distillation residue with an iron concentration adjusted to 520 ppm by mass. The obtained distillate was analyzed by gas chromatography. As a result, cumene, α-methylstyrene, and phenol were obtained with a thermal decomposition efficiency of 85%, a cumene recovery rate of 52%, a phenol recovery rate of 87%, and an α-methylstyrene recovery rate of 31%.

[0071] Comparative Example 3 The same flow reaction as in Example 6 was carried out using the same apparatus and iron-free phenol distillation residue. The obtained distillate was analyzed by gas chromatography. The results showed that cumene, α-methylstyrene, and phenol were obtained with a thermal cracking efficiency of 72%, a cumene recovery rate of 43%, a phenol recovery rate of 80%, and an α-methylstyrene recovery rate of 19%. The results of Examples 6 to 8 and Comparative Example 3 are shown in Table 2 below.

[0072] [Table 2]

[0073] [Example 9] A 600 mL SUS316L reactor equipped with a stirring device with a 400mm diameter carbon steel stirring blade, a condenser connected to a receiver for the distillate, a nitrogen inlet, a temperature detector, and a reaction liquid outlet was continuously pumped into the reactor. Low-boiling compounds, including cumene, α-methylstyrene, and phenol, were distilled off. Simultaneously, the reaction liquid was continuously withdrawn to maintain a constant liquid level in the reactor. A flow test was conducted for over 80 hours at a reaction temperature of 300°C and a residence time of 16.5 hours. The resulting distillate was analyzed by gas chromatography. The reaction results were a pyrolysis efficiency of 75%, a cumene recovery of 44%, a phenol recovery of 83%, and an α-methylstyrene recovery of 21%. The iron concentration in the reaction liquid after the reaction was 40 ppm by mass.

[0074] The following examples show examples of the method for producing the reaction solution (α). [Example 10] A 500 mL five-neck separable flask equipped with a stirrer, a condenser, a nitrogen inlet, and a temperature detector was charged with 378.8 g of phenol distillation residue, and 67.2 g of SS400 carbon steel plate was fixed inside the reactor so as not to come into contact with the stirring blade. The mixture was stirred at 150°C for 101 hours to produce a phenol distillation residue solution with an iron concentration of 2,200 ppm by mass.

[0075] [Example 11] A pipe with an inner diameter of 21.2 mm was packed with 5 mm diameter SS400 iron balls to a bed height of 90 mm, and phenol distillation residue obtained by the cumene process was passed through the pipe. While the phenol distillation residue was passing through, it was gradually heated, ultimately reaching a temperature of 165°C and a pressure of 0.2 MPaG. The phenol distillation residue was passed through at a flow rate of 10 mL / min at 150°C and 0.2 MPaG, and the liquid generated from the pipe outlet was collected, yielding a phenol distillation residue solution with dissolved iron.

[0076] [Example 12] A phenol distillation residue solution having dissolved iron was obtained in the same manner as in Example 11, except that the phenol distillation residue was passed through the piping at a flow rate of 5 mL / min.

[0077] [Example 13] A phenol distillation residue solution having dissolved iron was obtained in the same manner as in Example 11, except that the phenol distillation residue was passed through the piping at a flow rate of 1 mL / min.

[0078] The results of Examples 11 to 13 are shown below.

[0079] [Table 3]

[0080] [Example 14] A 300 mL four-neck flask equipped with a stirrer, a condenser, a nitrogen inlet, and a temperature detector was charged with 200 g of phenol distillation residue obtained by the cumene process and 0.5 g of SS400 iron powder. The mixture was gradually heated with stirring, ultimately reaching 150°C. After heating at 150°C for 13 hours, stirring was stopped and the supernatant was collected, yielding a phenol distillation residue solution in which iron had dissolved.

[0081] [Example 15] A phenol distillation residue solution in which iron had been dissolved was obtained in the same manner as in Example 14, except that 1.0 g of iron powder was used and heated at 150°C for 11 hours.

[0082] [Example 16] A phenol distillation residue solution in which iron had been dissolved was obtained in the same manner as in Example 14, except that 2.0 g of iron powder was used and heated at 150°C for 12 hours.

[0083] [Example 17] A phenol distillation residue solution in which iron had been dissolved was obtained in the same manner as in Example 14, except that 5.0 g of iron powder was used and heated at 150°C for 11 hours.

[0084] [Example 18] The same procedure as in Example 14 was carried out except that heating was carried out at 130°C, and a phenol distillation residue solution in which iron had been dissolved was obtained.

[0085] [Example 19] The same procedure as in Example 14 was carried out except that heating was carried out at 180°C, and a phenol distillation residue solution in which iron had been dissolved was obtained.

[0086] [Example 20] In Example 17, 200 g of phenol distillation residue and 0.5 g of iron powder were added to the residue remaining after recovering the supernatant, and the mixture was heated for 9 hours in the same manner as in Example 13, to obtain a phenol distillation residue solution in which iron had dissolved.

[0087] The results of Examples 14 to 20 are shown below.

[0088] [Table 4]

[0089] The production method of the present invention makes it possible to efficiently obtain components such as cumene, phenol, and α-methylstyrene in high yield using inexpensive catalyst components. Furthermore, this method also enables highly efficient recovery using a solution system rather than a solid catalyst component. From these perspectives, it can be said that this invention has industrially advantageous features.< / cphf> < / dpcf> < / phf> < / cumf> < / ph> < / cum> < / cphf> < / dpcf> < / cphf> < / phf> < / ph> < / cphf> < / dpcf> < / cumf> < / cum>

Claims

1. The method comprises thermally decomposing a liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol at 200 to 350°C in the presence of a catalyst component of at least one element selected from the group consisting of iron and zinc in a metal or metal ion state, to produce a liquid (B) having higher contents of cumene, phenol, and α-methylstyrene than the liquid (A).

2. 2. The method for producing liquid (B) according to claim 1, wherein the catalyst component contains iron metal, and the content of iron metal in the catalyst component is 89.5 to 100 mass %.

3. 2. The method for producing liquid (B) according to claim 1, wherein the catalyst component contains zinc metal, and the content of zinc metal in the catalyst component is 95.0 to 100 mass %.

4. The method for producing the liquid (B) according to any one of claims 1 to 3, wherein the catalyst component is a particulate catalyst component.

5. A liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol; contacting the solution with at least one solid selected from the group consisting of iron compounds and zinc compounds; A method for producing a reaction solution (α) containing a liquid (A) containing phenol, α-methylstyrene dimer, dimethylphenylcarbinol, and cumylphenol, and iron and / or zinc.

6. The method according to claim 5, wherein the iron compound has an iron metal content of 89.5 to 100 mass%.

7. 6. The method for producing reaction solution (α) according to claim 5, wherein the liquid (A) is contacted with at least one solid selected from the group consisting of iron compounds and zinc compounds using a flow-through fixed bed of at least one solid selected from the group consisting of iron compounds and zinc compounds.

8. 6. The method for producing the reaction solution (α) according to claim 5, wherein the liquid (A) is contacted with at least one solid selected from the group consisting of iron compounds and zinc compounds in a batch reaction tank.

9. The method for producing the reaction solution (α) according to claim 5, wherein the contact is carried out at 100°C or higher and lower than 200°C.

10. The method for producing the reaction solution (α) according to claim 5, wherein the iron compound is iron metal.

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