TW583167B - Decomposition of cumene oxidation product - Google Patents

Abstract

A process for decomposing a cumene oxidation product mixture containing cumene hydroperoxide (CHP) and dimethylphenyl carbinol (DMPC) to produce phenol, acetone and alpha-methyl styrene (AMS) with enhanced safety of operation and reduced by-product formation which comprises the steps: mixing the cumene oxidation product in a stirred or back-mixed reactor with an acid catalyst, with 10 to 100 percent acetone relative to the amount of acetone produced during the decomposition reaction, and with up to 4 weight percent additional amounts of water relative to the reaction mixture, at an average temperature between about 50 DEG C and about 90 DEG C for a time sufficient to lower the average CHP concentration of the reactor to between about 0.2 and about 3.0 weight percent, and wherein a portion of DMPC is converted to dicumyl peroxide (DCP); then reacting the reaction mixture from step (a) at a temperature between about 120 DEG C and 150 DEG C under plug-flow conditions for a time sufficient to decompose substantially all residual CHP and at least 90 percent of the DCP formed in step (a).

Description

583167 A7 ____B7 V. Description of the Invention (彳) This application is a continuation of US Patent Application No. 09 / 865,190, filed on July 23, 2001, and the latter is February 15, 1996. U.S. Patent Application No. 09 / 60,1,879 filed on the following day, which is a U.S. Patent Application No. 08 / 333,929 filed on November 3, 1994 No. of consecutive applications, which is a continuing application of U.S. Patent Application No. 08 / 203,845, filed on February 28, 1994, but has been suspended, which has been filed on July 24, 1992, but has been suspended US Patent Application No. 07 / 920,81 丨 continued application 'It is a subsequent application of US Patent Application No. 07 / 297,33, filed on January 17, 1989, but now suspended. Scope of the invention The present invention relates to a method for preparing phenol ', in which α-methylphenethylhydrazone (AMS) is obtained in a relatively high yield, which is a useful by-product. BACKGROUND OF THE INVENTION It is expected to be produced by the air oxidation reaction of anisin into anisin hydrogen peroxide (cHp) and the catalytic cracking of CHP acid into phenol and acetone. The chp decomposition reaction is a large exothermic reaction, which is generally carried out on a commercial scale in a continuous stirring or inverse mixing reactor. In such a reactor, at any selected time, only a small portion of CHP remains, and the reaction medium is basically the decomposition product of CHp (ie, Pan and acetone) and any solvent (such as: anisin) and CHP together with The composition of other substances in the reactor. During the oxidation reaction of anisin, a small amount of dimethylphenyl fluorenol (DMPC) and acetophenone were also formed. In the presence of an acid catalyst, DMPC is dehydrated to AMS (a useful by-product). Dehydrated on acid silica at 3 00 C, very high yields (such as: 98%) can be obtained from pure DMPC. 4 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 583167 A7 B7 V. Description of the invention (2) AMS. However, in the presence of phenol (especially phenol / acetone / anisole, which is the solvent for the decomposition reaction of the CHP / DMPC mixture), the AMS yield is usually about 50-60 mole% of DMPC. The main by-products are AMS dimer and anisol which have no commercial value. Formation of anisol also reduces phenol yield. G.G.Joris U.S. Patent No. 2,757,209 states that a two-stage reaction can substantially reduce the amount of AMS dimer and anisol formation. In the first stage, CHP is decomposed in a stirred or inverse mixing reactor in the presence of a small amount of sulfur dioxide (catalyst) and water (catalyst inhibitor). The preferred conditions are: temperature 4 5-6 5 ° C, sulfur dioxide 50-500 ppm, and water 2-5 wt%. Under these conditions, the CHP concentration in the reaction mixture discharged from the reactor is less than 5% by weight but higher than 1% by weight. In the second stage, the mixture discharged from the first reactor is heated in the second reactor, and optionally additional catalyst is used in the reactor to decompose the residual CHP and dehydrate the DMPC to AMS. This second reactor is a batch reactor or a continuous plug flow reactor. The preferred conditions are: temperature 1 10-120 ° C, and reaction time 5-15 minutes. Once AMS is fully formed, care must be taken to stop the high temperature reaction to minimize AMS dimerization or the reaction of AMS with phenol to form by-products.

U.S. Patent No. 4,358,61 8 to Sifniades et al. States that a three-stage CHP decomposition reaction is used to minimize the amount of AMS dimer and anisol formation. In the first stage, the CHP concentration was reduced to 0.5 to 5% by weight, and DMPC was converted to difenylated peroxygen (DCP) to an extent of at least 40 mole%. This reaction is carried out in a stirred or back-mixed reactor. The preferred conditions are: temperature 50-90 ° C, water 0.4-4.5% by weight, acid 50-75 ppm. In the second stage, the reaction mixture was passed through a plug flow reactor with a temperature substantially the same as that in the first stage. ^ _ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 583167 A7 B7 5. Description of the invention (3) Reduce the CHP concentration to less than 0.4% by weight. In the third stage, the reaction mixture is heated to 120-150 ° C in a plug flow reactor, which decomposes DCP and the remaining DMPC and CHP. In the two aforementioned patents, the main key is that a relatively high concentration of residual CHP is present in the first-stage reactor. In fact, we have found that in the three-stage process of U.S. Patent No. 4,358,618, the ultimate yield from 01 ^ 1? (: 8% 3 is usually increased with the increase of the residual CHP concentration in the first step. Unfortunately, the higher the CHP concentration in a stirred or back-mixed reactor, the more unstable the operation of the reactor, especially in large-scale reactors. This is because CHP decomposition is highly exothermic, and at the same time, due to increased temperature, Acceleration. Therefore, in the presence of relatively high concentrations of residual CHP, if the reaction is accelerated due to hot spots (local catalyst aggregation or other poorly controlled conditions), a large amount of thermal energy will be released. In a typical commercial inverse mixing reactor, the average Stable operation is difficult when the residual CHP concentration is higher than 2-3% by weight.

British Patent No. 1,202,687 of Societa1 Italiana Resine SP · A. States that the CHP decomposition reaction is performed at 30 ° to 70 ° C with acetone and 10 to 75% by weight sulfuric acid aqueous solution, so that the reaction product contains 37 to 48 weight. % Acetone and 0.0 5 to 1.0% by weight sulfuric acid, which can inhibit the formation of anisol and other undesirable concentrates. This reaction proceeds in a single stage. We have found that under the broad conditions indicated in the patent, it is possible to obtain reaction products containing large amounts of residual CHP. For example, if the reaction is performed at 30 ° C with a 10% sulfuric acid aqueous solution, the resulting reaction product contains 0.5% by weight sulfuric acid and 48% by weight acetone. However, it should be understood that mixtures containing highly reactive compounds (such as CHP) are not suitable for subsequent separation of reaction products by conventional means (such as distillation). Obviously, the patent case intends to apply the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 583167 A7 B7 to this paper size. 5.83 Description of the invention (4) The CHP decomposition reaction is substantially completed before the product is separated. We found that when all CHPs are decomposed in a single stage under the operating conditions specified in the patent, a large amount of anisol and AMS dimers are formed. In addition, DCP is also formed, here, there is no second stage to decompose DCP, which will further reduce the yield of useful products. If the operating conditions are modified with lower reactivity (eg, less acid, lower temperature) to inhibit the formation of anisol and AMS dimers, the DCP formation rate increases. Therefore, from some viewpoints, the method proposed in this patent cannot be used to improve the yield of useful products. SUMMARY OF THE INVENTION The present invention relates to the decomposition of the anisin oxidation reaction product into age, acetone, and AMS in high yields, and particularly to perform such a decomposition reaction in a relatively stable and economical manner. Adding acetone to the reaction product of the anisin oxidation reaction product, in addition to the acetone generally obtained by the decomposition reaction of CHP, obtains a relatively high yield of AMS, even if the residual CHP is as low as 0.2% by weight. An adiabatic flash treatment downstream of the crude product of the process is the most convenient way to obtain additional acetone. In this way, the thermal energy of the crude product is used to make recycled acetone and save energy. The overhead vapor produced in the first stage reactor or series of reactors can be re-distilled to obtain additional acetone. The acetone obtained in these ways may also contain a large amount of water. An embodiment of the present invention includes a method for decomposing a mixture of anisin oxidation reaction products containing CHP and DMPC to produce phenol, acetone, and AMS, and to improve the safety of operations and reduce the formation of by-products. The steps include: China National Standard (CNS) A4 (210X 297 mm)

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583167 A7 R7 5. Description of the invention (5 (a) The oxidation reaction of boswellin in the first reactor (such as: stirring or reverse mixing reaction preparation) with acid catalyst, relative to the acetone produced during the decomposition reaction Amounts of 10 to 100% acetone and an effective amount of water are mixed at an average temperature between about 50% and about 90% until the average CHP concentration in the reactor drops to between about 0.2 and about 3.0% by weight Among them, a part of * DMpc is converted into DCP; after that, (b) the reaction mixture from step (a) is reacted at a temperature between about 120 and 150 ° C under plug flow conditions until substantially All residual CHp and at least 90% DCP formed in step (a) are decomposed. In a preferred embodiment, the product from step (b) is subjected to an adiabatic flash treatment to recover the acetone-rich distillate, which Cycle to step & to obtain the acetone. In a preferred method, the acetone-rich vapor from the anisin oxidation product reaction mixture of step (a) is condensed in a condenser or heat exchanger to obtain the Acetone. In a preferred method, the effective amount of water is as high as the reaction mixture In a preferred method, an effective amount of water is up to about 4% by weight of the reaction mixture. In one embodiment, step (a) further comprises bringing the average CHp concentration between about 0.2 and The reaction mixture between 3.0 weight I / ❶ is reacted under plug flow conditions between 50 and about 90 ° C. until a reaction mixture having a CHP concentration of not more than about 0.4% by weight is produced. In one embodiment, this The invention includes a method for controlling variables in a reactor or a series of reactors to eliminate or mitigate changes in process operating conditions. These variables include residence time, temperature, acetone, and water content. One embodiment; One reactor content. In one embodiment

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5. Description of the invention (6) 'This method includes: supplying excess acetone to the reaction mixture in the first reactor, detecting the content of the acetone addition stream, and adjusting the feed rate of at least one of the input streams to compensate the acetone Flow content change; and controlling the residence time of the first reactor ° In one embodiment of the present invention, the method includes reacting the reaction mixture in the first reactor (or series of reactors) to cause the anisin oxidation product to CHP is decomposed into acetone and acetone, and DMPC in the oxidation product of anisin is converted to DCP, and the first reaction is performed in a second reactor with plug flow conditions and a temperature higher than that of the first reactor. The DCP formed in the reactor is converted into AMS and water. In addition, the method includes adding an excess of acetone to the reaction mixture (10 to 100% excess relative to the amount of acetone produced during the decomposition reaction), and optionally adding water in an adjustable feed stream. This example also includes detecting the amount of acetone added to the reaction mixture and adjusting the amount of water added to the reaction mixture based on the amount of acetone to maintain a substantially stable amount of water and acetone in the first reactor or series of reactors . In one embodiment, the acetone is recycled in a phenol plant (e.g., the acetone solution is recovered from the crude product stream after the DCP is decomposed into AMS or other effluent fluids) to provide a propylene solution. In one embodiment, the acetone solution is recovered and recycled from the outflow to the first reactor. In one embodiment, the average temperature in the first reactor (or series of reactions) is between about 50 ° C and 90 ° C. The temperature in the plug flow reactor used to dewater the DCP is The average temperature is higher than the average temperature in the first reactor, but the second average temperature is not--" — 一 _- 9 -__— This paper is suitable for size @ S 家 标准 (CNS) A4 specifications (21GX297 public love) '---

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583167 A7 B7 V. Description of the invention (7) Over 150 ° C. In one embodiment, the acetone-rich steam is back distilled in a first stage reactor or a series of reactors to obtain acetone. In one embodiment, the acetone recovery step includes cooling the acetone-rich vapor into an acetone-containing mixture, collecting the acetone-containing mixture in a container, and returning the acetone-containing mixture to the anisin oxidation product reaction mixture. In one embodiment, this method includes automatically adjusting the amount of additional water added to the reaction mixture to mitigate changes in the water mass composition of the circulating mixture added to the reaction mixture from the downstream steamhouse area. The amount of acetone added in this cycle is such that the amount of acetone is excessive and the amount of acetone in the reaction mixture is maintained to be about 500,000 / 0 to ιοο / 〇 higher than the amount of acetone produced during the decomposition reaction. In one embodiment, the reaction mixing level in the first stage cracking reactor or series of reactors is varied to control the residence time in the reactor or series of reactors. In one embodiment, the method includes controlling the concentration of CHP and DCP in the reaction mixture and controlling the residence time in the reactor. In one embodiment, the standard deviation of the temperature increase (herein referred to as d (T)) after the acid is added to the flow is lower. In one embodiment, this standard deviation falls below about 0.5. Brief description of the figure The one shown in Figure 1 is the first example of equipment used to implement the method of the present invention and includes a circulating acetone stream. Figure 2 shows the relationship between the AMS yield and the CHP concentration in the stirred reactor at 60%, 40%, and no acetone cycle. The paper shown in Fig. 3 is a second paper example of a device for carrying out the method of the present invention.

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583167 A7 _______ B7 V. Description of the invention (8) Schematic diagram 'which includes circulating acetone and back-distilling acetone streams. Detailed Description of the Invention The methods and procedures of the present invention comprise the following steps. In the first step, the anisin oxidation product is mixed with the acid catalyst, acetone, and the selected I water in the first cracking or decomposition reactor (basically a stirred or inverse mixing reactor) and maintained in the reactor. The CHP content decreases to between about 0.2 and about 3.0% by weight. In the second step, the effluent from step (a) is reacted in a plug flow reactor at an elevated temperature (between about 120 and 15 °. (Preferably between)) until it is completely decomposed into phenol, acetone and AMS. In the selected third step, it is better to collect acetone 'from the effluent from step (b) so that the effluent enters the evaporation step, and more preferably enters the adiabatic flash evaporation step. After the liquid is discharged from this library, it is recycled to step (a). Preferably, the effluent from the first reactor in step (a) is also maintained in the plug flow reactor until the CHP content is reduced to less than 0.4 weight before step (b) is performed. %. In these examples, the decomposition or cracking of CHP into phenol and acetone occurred in a series of reactors (such as: stirred reactor, inverse mixing reactor or plug flow reactor). Same or different. The acid catalyst used in the method is selected from the group consisting of sulfur dioxide, inorganic strong acids (such as: sulfuric acid, perchloric acid, etc.), strong organic acids (such as: toluenesulfonic acid), and Lewis acids (such as boron trifluoride). Or aluminum chloride The amount should be between 30 and 5ΰρριη (0.003-0.50% by weight). Preferred catalysts include sulfuric acid and sulfur dioxide. Salty acetone or acetone and aqueous solutions will be diluted / phase separated as Louis Reduce the strength of the acid catalyst and adjust the response by testing or both. But this ---------- · This paper size is applicable to the standard (CNS) A4 size (2K) × 297 public love) 583167 A7 B7 5 2. Description of the invention (9 places do not adhere to or rely on these theories to improve the specificity of the reaction. The acetone used in this method can come from any convenient source and can contain different amounts of water. The preferred source is acetone that has been prepared in a phenol production facility. Such as: adiabatic flash treatment of the effluent from (In addition, the flash treatment of the effluent cools the flash slag. Because generally the effluent stream must be cooled before being neutralized by the acid catalyst. Cooling will also reduce the cost of cooling, otherwise the production process will have to include this expense. Other sources used to make recycled acetone in phenol equipment include the top of the first reactor (or series of reactors) used to decompose CHP Distilled acetone-rich The steam or distillation is the acetone or waste stream. The evaporation of the reaction mixture helps to cool the reaction and control the reactor temperature. The acetone has a relatively high volatility. The steam basically contains a relatively high concentration of acetone and can be condensed and returned to the reaction mixture. It is known that these sources can be used to increase the amount of acetone in the reaction mixture prepared by the aforementioned reaction and can save energy, otherwise it is necessary to cool the reaction mixture or evaporate the added acetone. It is also known that these sources can be used alone or in combination. The amount of acetone added to the reaction mixture is from about 10% to about 100% of the amount produced during the reaction period. In a decomposition reaction of a bacillin oxidation product typically containing 80% by weight of CHP, the amount of circulating acetone is about 3% of the oxidation product. To about 30 weight 0/0. When the amount produced during the reaction is less than 10%, there is no obvious advantage for the reaction. Volumes above 100% are not economically attractive. Water is also generally produced during the dehydration and condensation reactions of DMPC. The additional amount of water is introduced into the plug flow reactor together with the circulating acetone, especially when it is obtained by flash evaporation of the second-stage decomposition reaction product. Acetone produced from this -12- This paper is sized for China National Standard (CNS) A4 (210X297 mm)

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583167 A7 B7 V. Description of the invention (10 may contain about 1 to about 5% by weight of water. Generally, the water produced by the reaction and the acetone are sufficient to adjust the activity of the acid catalyst. In the best case, the addition is small篁 Extra! Water to further adjust the catalyst activity, and in a better case, a controlled amount is used to compensate for the change in the amount of water introduced with the acetone. This is achieved by detecting the content of C = flow, and based on maintaining substantial stability The water T feed rate was adjusted by adding water and propionium to the reaction mixture of the first reactor or series of reactors. The total amount added should not exceed the weight of the reaction mixture: r%. Excessive Water makes the catalyst less active and slows down the reaction. The average temperature in step (a) is from about 50 t to about 9 rc. The temperature is maintained by a heat exchanger or by evaporative cooling. In the latter, the reactor pressure It can be substantially lower than atmospheric pressure to reach the desired temperature. When evaporative cooling is used, acetone is preferably obtained by condensing this vapor into a solution rich in acetone, and returns it to the reaction mixture. Residence time About 5 minutes to 2 hours. The goal is to maintain the average CHP concentration in the first reactor at about 0.2% by weight and about 3% by weight. Keeping in mind the following principles, changing the reaction conditions within the aforementioned range can achieve this goal: (a) The concentration of sulphuric acid catalyst, reactor temperature and residence time will reduce CHP concentration. (B) Increasing acetone concentration and water concentration will increase CHP concentration. If step (a) is performed in a well-stirred reactor, each reactor The difference between the temperature and CHP concentration of the point and its individual average is small. In such a reactor, detection at only one point is sufficient. However, when using an inverse mixing reactor, there are temperature and CHP concentration gradients, and their sizes It will depend on the shape of the reactor and the circulation ratio. In such a reactor, the average temperature and CHP concentration are -13- This paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 mm) gutter 583167 A7 B7 _____ V. The description of the invention is sufficient to mean the temperature and concentration of the homogenized matter in the reactor. To estimate the average value: the temperature and CHp concentration must be detected at multiple points. Detecting which are the basic elements for the success of this method. For stable and safe operation, it is better to analyze CHP simultaneously. This can be done by using a% hydrogen automatic titrator or measuring foot in a strongly acidic ion exchange resin (as described in Mitsui's Japanese Patent No. 7'446,278). ) The temperature of the reactor effluent in the upper cycle is increased, or the temperature is reached. US Patent No. 4,358,6 18 states that it is desirable to ensure that the CHP content in the reaction mixture is lower than 0 before completing the reaction of step ⑻. 4% by weight. This is because the relatively high-temperature heating of a good step will slightly increase the formation of by-products. By using the step, further complete the "decomposition reaction" step in the step "Step" Usually using a tube, the residence time does not exceed a few minutes . In the method of the present invention 4, the CHp content in the effluent from step (a) can be lower than 0 2 2%. Step (d) is not required at this time. Even when the CHp content is high, a large amount of decomposition occurs during the heating period of the heat exchanger (part of step (b)), which satisfies the function of step (d), so step (d) can be omitted. An embodiment of the present invention using cyclic acetone is shown in FIG. 1, which can be compared with FIG. I of US Pat. No. 4,358,618. The step is carried out in the reverse mixing reactor 1 at a temperature between 50 ° C and 90 ° T, and the residence time is 5-120 minutes. Industrial-grade CHP, propylene glycol, acid catalyst, and water are led to the reactor through inlets 2, 3, and bucket 5, respectively. The desired temperature is maintained by circulating through the cooler 6. Since the CHP decomposition reaction is exothermic, the minimum residence time in reactor 1 (including the time in cooler 6) depends on the design of the cooler and the nature of the coolant. When the coolant is water, the actual lower limit is about 5 minutes. When using the refrigeration system ___ _ -14- This paper is applicable to the standard (CNS) μ size (2iGX2 · love) ---; 583167 A7

Time can be shorter. The upper residence time depends on the temperature of the reaction mixture, the 2 :, acetone content and water content. The maximum residence time is approximately 120 minutes. The preferred residence time is between 10 and 60 minutes. 2 The product from reactor 1 is then pumped to heater 8 via tube 7. The reaction step ⑷ can be carried out in the tube 7, which can have sufficient capacity so that the dwell time is between 0.1 and 5 minutes. The temperature in the tube 7 is about the same as that in the tube. It was not used for cooling because the only significant reaction that occurred at this step was the decomposition of residual CHP (which had been reduced to 0.2-3% in step ⑷). Heater 8: The product is heated to 120-150 ° C, and then pumped through the isolation line 9 to a flash of 10 °. Step (b) is performed in the heater 8 and the line 9, that is, the DCP decomposition reaction and the DMPC dehydration reaction for turning AMP into AMP and any residual chp complete decomposition reaction. Because of these reactions, the outlet temperature of line 9 is usually slightly higher than the temperature of the thermal parent to 8 outlet temperature. Compared with the residence time in line 9 (at least 30 seconds), the residence time in heater 8 is relatively short (eg, less than 30 seconds), because most of the residual DMPC and DCP are higher. Temperature decomposition, which is favorable for the formation of AMS, so the best amS yield can be obtained. Line 9 is equipped with sampling ports at the inlet 9A, the intermediate point 9B and the outlet 9C to detect the DCP concentration. The reaction product at 'step (c)' at 10 flashes was cooled for 10-60 minutes. It was further cooled to 30-50 ° C by a cooler U, and then sent to anion exchange resin bed 12 to neutralize the acid catalyst. The neutralized product then enters the distillation system through line 3 to branch and recover various components. The acetone-rich column overhead from the flasher was recycled via inlet 3 into the inverse mixing reactor. It has been found that the method of the present invention is beneficial for improving the stability of the decomposition reaction and reducing the change in AMS yield encountered with the commercial production of phenol from the oxidation product of bacillin. This paper size applies to China National Standard (CNS) A4 (210 X 297 public love)

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583167 A7 B7 V. Description of the invention (13) It is also believed that the present invention substantially reduces the procedures caused by the poor control of the first decomposition reactor (or multiple reactors) or their auxiliary systems in many commercial anisin oxidation product decomposition systems Instability. Examples of these instabilities include high local concentrations of acid catalysts, shocks in the acetone stream that are recycled or re-distilled, and changes in the reactor feed stream content. This instability will cause the rate of decomposition in the first reactor to change, which will cause the amount of residual CHP present in these reactors and the amount of DCP produced by these reactors to vary. Current operating methods for these systems detect the temperature of the reaction mixture and the reaction mixture d (T) at one or more points in the reactor. These parameters are detected periodically and adjusted to control the decomposition reaction. However, these methods are not sufficient to control the reaction. Changes in the concentration of CHP and DCP in the mixture will lose the AMS yield and increase the aforementioned by-products. In addition, a large amount of the reaction mixture is recycled in one or more reactors, and cooling / retorting acetone for evaporation or acetone is circulated in the reactor system for evaporation. These changes in CHP and DCP concentrations start system feedback. In the long run, The average concentrations of CHP and DCP deviate unexpectedly, and the d (T) measured from the reaction mixture is worth knowing. Following these instabilities, the phenol plant operator establishes a maximum amount of CHP (and DCP), which can be contained in the reaction mixture and sent to the dehydration reactor. Because the d (T) value is used to detect the concentration of CHP and DCP to prevent damage to the equipment system downstream, the upper limit of d (T) of the reaction mixture is set. When this value is exceeded, the equipment operator must correct it (eg, increase the residence time in the reactor, increase the acid concentration to an optimum level, or even shut down the reactor), thereby significantly reducing the equipment's phenol, acetone, and AMS levels. Operator corrections can also only delay the response. A typical lag time between completion and effecting dT can range from 1 to 30 minutes. Too much or lack ___- 16-_ This paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm) 583167 A7 B7 5. Description of the invention (14) CHP will reduce the yield of AMS, phenol and acetone. Therefore, to maintain the safety margin, the actual operator of the equipment must maintain the average CHP concentration and d (T) value far below the maximum allowable amount, so that the program instability can be measured by the d (T) value without having to bear the reactor shutdown Or risk of damage. This amount must also take into account the delay between unstable conditions (causing d (T) to rise or fall) and its detection. Statistically speaking, the value of d (T) changes greatly (standard deviation is greater than 1), and the operator must set the reaction conditions of the first reactor below the optimal d (T) to prevent this change from increasing sharply or exceeding the maximum allowable amount. In practice, this will reduce the AMS yield. In addition, it has been found that commercial equipment also operates with a reactor having a set reactor level, where the total volume of reactants in the first reactor is stable. Because process instability may require the operator to adjust the feed rate of the fluid into the first reactor, these instabilities can have an additional impact on the residence time of the reaction mixture in the first reactor, in continuous or recirculation systems Even more so in China. These variables include the residence time of the reaction mixture in the first stage reactor or series of reactors, the reactor temperature in the first stage reactor, and the acetone and water concentrations in the first stage reactor. By reducing or eliminating these variable changes, the process becomes more stable, increasing the amount of DCP used to convert to AMS in the second-stage reactor. This increase can be indirectly counted as a differential card. After the acid catalyst is added to the flow from the system (preferably from the first stage or plug flow reactor), the temperature change from the small side stream d (T ) Measured. The higher the residual amount of CHP and DCP, the larger the d (T) value. Figure 3 is a device according to another embodiment of the present invention, which includes a stirred first-stage cracking reactor, a condenser (to return acetone to the first-stage reactor), and (CNS) A4 size (210 X 297 mm)

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Line 583167 A7 _B7 _ ^ _ V. Description of the invention (15) The second stage dehydration reactor (such as a plug flow reactor). The yield of AMS from the dehydrator in this example is high, so it is necessary to study the cause of the unstable procedure. During three years, in two reactors designed as shown in Figure 3, the reactor level was set and the residence time was not controlled, and the AMS yield ranged from as low as about 63 mole% to as high as about 83 mole%. The annual averages are 75.2 mole%, 72.8 mole%, and 77.7 mole%. Investigating the source of this change, it was found that the change was mainly due to the reaction mixture content in the first stage reactor. Program research shows that the d (T) value of this method varies greatly, both for short-term d (T) values (eg: 1-3 minutes) and long-term d (T) values (eg: 15-40 minutes). Long-term changes are due to changes in residence time and water concentration in the reactor. In particular, the exact residence time of the reactants (such as CHP, DMPC, DCP, etc.) changes substantially due to changes in the amount of acetone and water in the first-stage reactor. The residence time can be controlled by having the liquid level in the first stage cracking reactor (also referred to herein as a decomposer or first reactor) change depending on the total feed rate into the reactor, but these changes Of course, it must be within the safety parameters of each reactor. Surprisingly, by changing the reactor level, especially with the change, and adjusting the feed rate of the anisin oxidation product, the long-term change in the residence time of the reaction mixture in the first-stage reactor will basically fall below the detection level. Side-critical. The following examples further illustrate the invention. Example 1 Contains 81.6 wt./CHP, 5.00 wt.% DMPC, and 0.40 wt.% Acetophenone. The mycelin oxidation product, most of which are lycopene, is 1.62 g / min-18. This paper size applies to the country of China Standard (CNS) A4 specification (210X 297 mm) 583167 A7 R7 V. Description of the invention (16) The clock rate is pumped to a thermally stable pyrex Mortor bottle equipped with a magnetic stirrer. The 'overflow device makes the reaction mixture The volume was maintained at 30 liters. At the same time, the same solution containing 0.88% by weight of 8 "3, 2.06% by weight of phenol, 5.83% by weight of anisin, 60% by weight of water, and 0. 05% of 12% by weight of sulfuric acid in 0.23 g The rate per minute is pumped into the reactor. The composition of the acetone solution (except for the acid content) corresponds to the composition of the pressurized distillate obtained from the reaction product. The added acetone corresponds to about 40% of the acetone produced during the reaction period. Calculation The acid content is maintained at 80 ppm in the reaction mixture. The residence time in the reactor is 16 minutes and the temperature is 80 ° C. The reactor effluent is agitated and drawn through 1/8 inch stainless steel immersed in 125. Tube reactor. The residence time in the tube is 16 minutes. When the two reactors reach steady state operation, samples are obtained at the outlet of each reactor for analysis. After that, the temperature of the immersion liquid in which the tube reactor was immersed increased to 135 ° C, and then increased to 145 ° C. In each case, after the system reached a steady state, samples were taken for analysis. The effluent from the tax reactor contained an average of 2.26% by weight DCP and 051% by weight residual CHP. This effluent AMS yield in liquid It is 47%. The yield of AMS in the effluent of the tubular reactor at 1,25, 135 and 145 ° C is 78.0 and 78.3 mole%, respectively. The AMS yield is calculated as follows: Yield = 100x (AMS-AMS. ) / (CE-AMS〇) where AMS〇 is the AMS concentration of the feed, CE is the total methanol equivalent, which is defined as the sum of all products that can be formed by the DMPC reaction. The main components of CE are DMPC, AMS, DCP, AMS dimer and coumol. Other examples use substantially the same anisin oxidation products, but the reaction conditions used are listed in Table 丨. Examples 7 to U are not added for comparison. Examples

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Line 583167 A7 _B7___ 5. In the description of the invention (17) 12, the added acetone is equivalent to 60% recycled acetone, but the sulfuric acid is increased to 0.5 OOppm, and the residence time is 20 minutes, so that the residual concentration of CHP in the effluent of the stirred reactor It is essentially 0. DCP is 0.55% by weight. The AMS yield in the stirred reactor effluent was 62.6%, which increased to 68.1% after further reaction at 125 ° C in a tubular reactor. In some examples, a post-reactor is used which is isothermal to the stirred reactor. This is a 1/8 inch stainless steel tube with a residence time of about 3 minutes. The maximum AMS yields obtained from these examples are plotted in Figure 2 with respect to the residual CHP concentration in the stirred reactor. The bottom curve (the hollow square) represents an example without the acetone cycle. The middle curve (one with an X in the box) represents an example with a 40% acetone cycle. The upper curve (solid square) represents an example with 60% acetone cycling. It is clear from Fig. 1 that by circulating acetone to the stirred reactor, a good AMS yield can be obtained. When the residual CHP concentration is relatively low, less slag is formed. It can also be clearly seen that when the residual CHP concentration falls below 0.2% by weight, the AMS yield substantially slips, even if the acetone is recycled to the stirred reactor. -20- This paper size applies to China National Standard (CNS) A4 (210X 297 mm) 583167

V. Description of the invention (18) The table should reverse the production of oxygen A. Anise.% Cyclic ketone-propion. The device should be stirred. 2 4 6

0 12 >-< 11 1X 4040404060600000060%) Amount 3 PCD%) Amount M Η cx) ^ 1 ¾ Temperature% Add I water i 110080334440 229909008831 592139227020 0.0.2.2.0.2.0.0.11.20. 6 2 51772300175 77273768615 ··· ♦ _ · «··· 234 414 225 350 Installed reactor CHP (wt%) AMS yield plug flow temperature ΓΓΛ 125 135 145 I — 75.1 78.0 78.3 2 — 78.3 82.6 83.7 3 — 75.7 84.3 85.7 4 0.12 75.7 84.3 85.4 5 0.04 77.3 79.1 80.1 6 O.ll 81.0 86.8 84.1 7 0.06 67.2 66.2 65.0 8 — — 65.1 — 9 — 79.8 80.5 78.4 10 — 75.7 76.3 75.1 II 0.15 79.3 82.1 82.4 12 — 68.1 — Hua · H2S〇4 = 80ppm and 20 minutes. Time = 16 minutes, but 500ppm in Example 12 21-This paper size applies to China National Standard (CNS) A4 (210X 297 mm) line 583167 A7

& plus = feed rate of the stream to compensate or moderate the C_ stream.

Installed, so that the reactor level changes to control the residence time, use] o to systematically adjust the feed rate of the water addition liquid flow, to control dT mainly at the selected set point, and to automatically adjust to compensate for the cyclic acetone Water content changes. " The change in the level of response and response levels before and after the compensation or mitigation control confirms the advantages of the present invention. First of all, the Zhao test was performed for more than 20 days without controlling the dwell time and without controlling the dwell time, and the dT value changed from 6 to over 16 over a long period of time. During this comparison period, where?乂 The operation of the method of the prior art ’For example, the operator detects the bite, responds to the dT, and the artificial mallet moves to or reduces the residence time of the reactor or the feed rate of water. As shown in Table 3 below, 'many processing times are used for this above or below the preferred amount to improve AMS production ^ 5 days sample was taken from this 20 photo period' to test with 5 days obtained from the same reactor Kind of comparison. During the 5-day test period, the reactor level changed by about i0% of the reaction mass, and the typical change was between about 0% and 6%. Data were collected during the 5-day test period, and DCS (GSE) was also used. The results are shown in Table 3 below. A1 Feed (gpm) during reactor capacity setting control Program stability average dT Low high standard deviation No No 20 days 135 Unstable not measured 6.0 16.3 Not determined No No 5 days 135 Unstable 10.66 6.0 16.3 1.63 _ Yes 5 Day 129 was stable at 11.95 10.75 13.75 0.38_-d (T) The standard deviation decreased from 1.63 to 0.38, the average value was 11.95, from 6.5 to about 7.1% by weight concentration, and the residence time increased. Water feed-24 is also detected and recorded-This paper size applies Chinese National Standard (CNS) A4 specification (210X 297 mm) 583167 A7 B7 V. Description of the invention (22) Relevant average values of rate and residence time, these results Listed in Table 4 below. Table 4 Mean dT water feed rate retention time during the existence of reactor capacity setting control No No 20 days Not measured 0 to 2 4 to 8 No No 5 days 10.66 1.33 6.66 Yes 5 days 11.95 1.49 6.99 Completed relaxation control and residence time control After that, the average water feed rate increased slightly from 1.33 to 1.49, and the residence time increased from 6.66 to 6.99. Using set reactor levels and control methods of the prior art, basically, in response to a short increase in dT, increasing the water feed and increasing the residence time to reduce dT and thus reduce the AMS yield. On the contrary, using the control method described here, the stability of the program is improved to ensure the safe operation of the program, and the average dT is from 10.66 to close to 12, and the AMS yield is relatively increased as expected. -25- This paper size applies to China National Standard (CNS) A4 (210X 297mm)

Claims (1)

583167, \ r- usurp the first case AB c D \ —- / 11 months of the year (92, please apply for this application for the replacement of the special perimeter number 145 5 special 1124, please — fAr & VI. Patent application scope 1. A decomposition Process for producing phenol, acetone and α-methylphenethylhydrazone (AMS) comprising anisin, anisin hydrogen peroxide (CHP) and dimethylphenylmethanol (.DMCP) oxidation product, comprising steps : Provide the first reaction mixture, which includes the oxidation product of anisin, an acid catalyst, and an acetone solution (wherein the amount of acetone is added to the reaction mixture from 10 to 100% of the amount of acetone produced during the decomposition reaction) And selected water, which is added in the liquid stream at an adjustable feed rate; the reaction mixture is reacted in a first reactor at a first average temperature to obtain phenol and acetone, wherein the DMPC Conversion to difenylated peroxygen (DCP); reacting the reaction mixture in a second reactor under plug flow conditions at a second average temperature until DCP decomposes into AMS and water to form a product mixture; from the product The mixture recovers the acetone solution; The acetone solution from the product mixture is circulated to the first reaction. 33. Moxibustion, the acetone solution content is detected analytically; and the feed rate of water is adjusted depending on the acetone solution content; wherein the first average temperature is between 50 Between ° C and 90 ° C, the second average temperature is higher than the first average temperature, but the second average temperature does not exceed 150 ° C ^ 2. If the method of the first scope of the patent application, It also includes making the first reaction paper size applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) 67 IX 3 δ 5 A BCD 6. The level of the reaction mixture in the scope of the patent application. 3. If the scope of the patent application The method of item 1 further comprises back-distilling the acetone-rich overhead distillate steam obtained by the CHP decomposition reaction in the first reactor. 4. The method of item 1 in the scope of the patent application, wherein the The first reactor contains a series of reactors, but at least one reactor has plugging conditions. 5. A method for producing phenol, acetone, and AMS by using an acid catalyst through the decomposition reaction of the anisin oxidation product. This method usually has A decomposition system having a first reactor, a set of input fluids, the set of input fluids including a circulating acetone stream, a water stream, and an anisin oxidation product feed stream, the reaction mixture comprising phenol, acetone, DCP and CHP, the reaction The mixture is decomposed by the silver to the two decomposition systems to produce a mixture containing g, g, and AMS, which comprises: providing excess acetone in the reaction mixture; detecting the contents of the circulating acetone stream; adjusting at least one of the input fluids Feed rate to compensate for changes in content in the circulating acetone stream; and control the residence time of the first decomposition system. 6. The method according to item 5 of the patent application, further comprising the step of re-distilling the acetone vapor in the first decomposition system. 7. The method of claim 5 in which the average concentration of DCP in the reaction mixture is increased, and the standard deviation of the average concentration is reduced. 8. As the method of applying for item 5 of the patent scope, thereby mitigating the long-term changes in the concentration of CHP and DCP in the reaction mixture, so that the dT standard during the 5-day period is biased. -2- This paper size applies the Chinese National Standard (CNS) A4 specification 210X297 public love) 583167 A8 B8 C8 _____D8 6. The difference in the scope of patent application is less than 1.6. 9. A method as claimed in claim 5 of the patent application, whereby the long-term changes in the concentrations of CHP and DCP in the reaction mixture are mitigated so that the standard deviation of dT during the 5-day period is less than 0.6. 10. The method according to item 6 of the patent application, further comprising the step of changing the level of the first reactor. 11 The method of claim 8 in the scope of patent application, wherein the feed rate of the water stream is adjusted to compensate for changes in the content of the circulating acetone stream. 12. The method according to item 6 of the patent application, further comprising the step of changing the level of the first reactor by 15% of the average level of the reaction mixture. 13. The method of claim 12 in the scope of patent application, wherein the long-term deviation of the concentrations of CHP and DCP in the reaction mixture is substantially eliminated. 14. A method for producing hydrazone and propane by the decomposition reaction of anisin hydrogen peroxide by adding an acidic catalyst, comprising a series of reactors, a circulating acetone stream, a water addition liquid stream, and a reaction mixture containing excess acetone It includes: re-distilling acetone-rich steam in the reactor, detecting the content of the circulating acetone stream, and automatically adjusting the water addition liquid stream to mitigate the change in the composition of acetone and water in the circulating acetone stream, Wherein the excess acetone is maintained in the reaction mixture by 10 to 100% by weight higher than the amount of acetone produced during the decomposition reaction. 1 5. The method of item 14 in the scope of patent application, which further includes making the first reaction -3-This paper size applies Chinese National Standard (CNS) A4 specification (21〇297297 mm) A8 B8 C8 583167- -------- -______ 21 6. The level of the patent application scope changes, and the residence time of the anisin oxidation product in the first reactor remains stable. 16. The method according to item 14 of the scope of patent application, thereby substantially eliminating the long-term change in the concentration of CHP and DCP in the reaction mixture. 1 7 · —A method for improving the decomposition reaction of anisin oxidation products by adding an acidic catalyst and using a series of reactors, wherein the improvement includes: preparing the reaction mixture in a decomposition reaction relative to the oxidation products of anisin 10 to 1000/0 excess acetone in the amount of acetone; maintaining a stable residence time of the anisin oxidation product in a series of reactors, and changing the level in the first reactor. 18 · The method according to item 17 of the scope of patent application, which substantially eliminates the long-term changes in the concentrations of CHP and DCP in the series of reactors. 19. The method according to item 17 of the scope of patent application, wherein the step of providing an excess of 10 to 1000/0 acetone comprises the following steps: enriching the steam obtained from the overhead steam in a series of reactors The vapor of propylene copper was condensed into the first propylene solution; the first acetone solution was returned to the series of reactors; the reaction mixture was moved to an isolation tank; the reaction mixture was subjected to flash treatment to obtain a first Two acetone solutions; and a second propionate valley solution was transferred to a series of reactors. 20 · Apply the method in item 19 of the patent scope to improve the average yield of AMS. Pretend This paper size is applicable to Chinese National Standard (CNS) A4 specification (210 X 297 mm) 583167 A8 B8 C8 D8 VI. Application for patent scope 2 1 · If the patent scope of the patent application is cleared, the method of adjusting the water into the reactor is 19 Feed rate to mitigate changes in the ratio of acetone and water to phenol in the first reactor. 22. The method according to item 19 of the application, wherein the acidic catalyst is selected from the group consisting of sulfuric acid, sulfur dioxide, trifluoride, toluene acid, and chloride. 23. The method according to item 19 of the scope of patent application, wherein the series of reactors includes the first reactor, and the first average temperature of the first reactor is between 5 (TC and 9 (TC, the first The two reactors are substantially isothermal to the first reactor, the second reactor plug > J5L condition, and the third reactor 'the third reactor plug condition' second average temperature is high Average temperature at the first reactor, but the second average temperature does not exceed 150 ° C. 24. The method according to item 23 of the patent application, wherein the second average temperature is from 120 ° C to 150 ° C. 25 · —A method for increasing the selectivity of the anisin oxidation product to pan and acetone by using an acidic catalyst, which uses a first reactor and at least one plug flow reactor downstream of the first reactor, The average temperature of at least one plug flow reactor is higher than that of the first reactor and includes: the decomposition of coumarin hydrogen peroxide in the first reactor in the presence of a substantially stable amount of water and excess acetone ' Relative to the amount of acetone produced during the decomposition reaction The amount of excess acetone is an excess of 10 to 100%; wherein, the residence time of CHP in the first reactor maintains a stable time and changes the level of the first reactor. 26. Such as the scope of the patent application No. 25 Method, which further includes providing additional water to the paper size applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 583167 A8 B8 C8 D8 6. The reaction mixture in the first reactor of the patent application scope, and Control of the mass% of water and acetone present in the first reactor 27. An improved method for decomposing anisin oxidation products into AMS, phenol and acetone in a series of reactors, comprising: The acetone produced by the decomposition is recycled to the reaction mixture to supply excess acetone; the content of the acetone is detected by on-line analysis to generate a signal; the signal is used to automatically adjust the feed rate of additional water to a series of reactors And change the level of the reaction mixture in a series of reactors. 28. An improved method as claimed in item 27 of the patent application, wherein The amount of acetone, the amount of excess acetone is an excess of 10 to 100%. 29. The improved method according to item 28 of the scope of patent application, wherein the anisin oxidation product, acid catalyst and excess acetone are supplied to the first reactor, since The first reactor collects acetone-rich steam, condenses and returns to the first reactor. 30. The improved method according to item 27 of the patent application, wherein the coumarin decomposition product of argon peroxide is added. The amount of additional water in the reaction mixture does not exceed 4% by weight based on the reaction mixture. 3 1. The improved method according to item 29 of the patent application, wherein the level of a series of reactors is changed according to the average level of the first reactor. The improved method of the 31st scope of the patent application, wherein the level change is equivalent to 10% in a 5 minute period relative to the average level of the first reactor. -6- This paper size is in accordance with Chinese National Standard (CNS) A4 specification (21〇χ 297) " '583167 Λ8 B8 C8 D8 6. Application for patent scope 3 3. If the 27th improvement method of the patent scope is applied, It further comprises the steps of producing acetone-rich steam in the first reactor, condensing the acetone-rich steam and returning the condensate to the first reactor. 34. The method of claim 33, wherein the acetone-rich vapor is condensed in a tank separated from the first reactor. This paper size applies to the Chinese National Standard (CNS) A4 specification (210X 297 mm) 583167 Patent Application No. 091124514 Chinese Schematic Replacement Page (November 1992) -35- 583167 Patent Supplement No. 091124514 Chinese Supplementary Specification (November 1992) Schematic Element Symbol Brief Description Symbol 1 2, 3, 4, 5 6 7 8 9 9A 9B 9C 10 11 12 13 30 32 34 35 36 37 38 40 42 44 46 48 50 Meaning Inverse mixing reactor inlet cooler tube heater isolation line inlet midpoint outlet flash evaporator cooler anion exchange resin bed line anisin oxidation product decomposition reaction system first reactor anisin oxidation product stream Acetone flow water feed stream circulation acetone stream sulfuric acid feed stream condenser back distillation acetone collection tank line second reactor decomposition product mixture stream flush P: \ LST \ 2003C \ 79676 circle symbol at description.DOC \ 丨 \ LAN