Toluene oxidation reaction device

Abstract

A toluene oxidation reaction device is characterized by comprising a toluene oxidation reactor, a cooling coil pipe, a gas-liquid separation tank, a primary condenser, a multi-stage condensation separation recovery assembly, a first circulating pump and a second circulating pump, the toluene oxidation reactor is provided with a condensation coil pipe, one end of the condensation coil pipe is connected with a water outlet of the gas-liquid separation tank, and the other end of the condensation coil pipe is connected with a water outlet of the primary condenser. The other end of the condensing coil is connected with a liquid return opening of the gas-liquid separation tank through a first circulating pump, a gas phase outlet in the top of the toluene oxidation reactor is connected with a primary condenser, and the primary condenser is connected with a water outlet of the gas-liquid separation tank through a second circulating pump; a water outlet of the primary condenser is connected with a liquid return port of the gas-liquid separation tank, the primary condenser is connected with the multi-stage condensation separation recovery assembly, and the utilization efficiency of heat in production is improved by utilizing the principle that toluene oxidation reaction is exothermic reaction; and the multistage condensation separation recovery assembly conveys the obtained toluene to the reactor, so that the resource waste is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to toluene oxidation reaction system technical field especially relates to a toluene oxidation reaction device. BACKGROUND

[0002] The industrial production of benzoic acid is generated by the reaction of toluene, catalyst and air in the toluene oxidation reactor under the conditions of reaction temperature 158-174 DEG C and reaction pressure 0.49-0.6 MPa.

[0003] In the process of producing benzoic acid, the liquid phase product in the reaction product is a mixture of benzoic acid, excess unreacted toluene and a small amount of by-product benzaldehyde, benzyl benzoate and the like, which is transported to the rectification section for rectification separation treatment, and the gas phase product in the reaction product is a mixture of residual nitrogen in air, reaction generated water vapor, part of evaporated toluene and a small amount of benzoic acid, which is directly condensed and recovered by the primary condenser and then discharged, and there is still a mixture of toluene or benzoic acid in the discharge, which not only pollutes the environment, but also has low recovery efficiency of toluene and benzoic acid, causing waste.

[0004] Therefore, a toluene oxidation reaction device is designed to solve the above problems. UTILITY MODEL CONTENTS

[0005] In view of the above technical problems, the utility model provides a toluene oxidation reaction device, characterized by comprising a toluene oxidation reactor, a cooling coil, a gas-liquid separation tank, a primary condenser, a multistage condensation separation and recovery assembly, a first circulating pump and a second circulating pump,

[0006] The toluene oxidation reactor is provided with a condensing coil, one end of the condensing coil is connected with the water outlet of the gas-liquid separation tank, the other end of the condensing coil is connected with the liquid return port of the gas-liquid separation tank through the first circulating pump, the gas phase outlet at the top of the toluene oxidation reactor is connected with the primary condenser, the primary condenser is connected with the water outlet of the gas-liquid separation tank through the second circulating pump, the water outlet of the primary condenser is connected with the liquid return port of the gas-liquid separation tank, and the primary condenser is connected with the multistage condensation separation and recovery assembly,

[0007] The multi-stage condensation separation recovery assembly is composed of a primary gas-liquid separation tank, a secondary condenser, a secondary gas-liquid separation tank, a tertiary condenser, a tertiary gas-liquid separation tank, a quaternary condenser, a quaternary gas-liquid separation tank and an acid water tank, the primary gas-liquid separation tank is connected with the primary condenser, a liquid inlet of the primary gas-liquid separation tank is connected with a liquid inlet of the toluene oxidation reactor, a top gas outlet of the primary gas-liquid separation tank is connected with the secondary condenser, the secondary condenser is connected with the secondary gas-liquid separation tank, a top gas outlet of the secondary gas-liquid separation tank is sequentially connected with the tertiary condenser, the tertiary gas-liquid separation tank, the quaternary condenser and the quaternary gas-liquid separation tank, a liquid outlet of the secondary gas-liquid separation tank, a liquid outlet of the tertiary gas-liquid separation tank and a liquid outlet of the quaternary gas-liquid separation tank are all connected with the acid water tank through pipelines, and an upper separation outlet of the acid water tank is connected with the liquid inlet of the toluene oxidation reactor through a pipeline,

[0008] Specifically, a pressure control valve is arranged at the top gas outlet of the quaternary gas-liquid separation tank, nitrogen with a pressure of 0.45 MPa is delivered to a tail gas refrigeration generator set after the energy of the residual pressure generated by power generation is recovered, and normal pressure nitrogen is delivered to a tail gas adsorber and discharged after treatment.

[0009] Specifically, the secondary condenser, the tertiary condenser and the quaternary condenser are all connected with a water circulation cooling device.

[0010] Specifically, a liquid inlet is arranged on one side of the lower end of the toluene oxidation reactor, and toluene and a catalyst used in the reaction are delivered into the tank from the liquid inlet.

[0011] Specifically, an air inlet is arranged at the bottom of the toluene oxidation reactor, and air is delivered into the toluene oxidation reactor from the air inlet.

[0012] Specifically, a liquid phase outlet is arranged on one side of the upper end of the toluene oxidation reactor, and the outlet is connected with a rectification section.

[0013] Specifically, a lower separation outlet of the acid water tank is connected with a sewage treatment device, and wastewater in the lower layer of the acid water tank is delivered to the sewage treatment device.

[0014] The utility model discloses the beneficial effect:

[0015] The utility model discloses the principle that toluene oxidation reaction is exothermic reaction, sets up 6 sections of cooling coil on toluene oxidation reactor, and 130-152 DEG C water in vapour -liquid separation tank is delivered to cooling coil by water level difference, and cooling coil carries out heat exchange and cooling, and the reaction heat in reactor is taken away and returns to vapour -liquid separation tank, makes vapour -liquid separation tank produce 0.2MPa-0.4MPa saturated steam, supplies production use, improves the utilization efficiency of heat in production,

[0016] The utility model discloses a multistage condensation separation recovery assembly, and the toluene and benzoic acid in the gas phase product generated by the toluene oxidation reactor are recycled, the toluene separated out is sent to the toluene oxidation reactor for continuous reaction in the first gas-liquid separation tank, and the toluene and benzoic acid separated out are transported to the toluene oxidation reactor for reaction after being treated by the acid water tank in the second, third and fourth gas-liquid separation tanks, which greatly improves the material resource utilization rate and reduces material waste. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The utility model discloses a toluene oxidation reaction device's structure connection flow chart;

[0018] As shown in the figure: 1. Toluene oxidation reactor, 11. Gas phase outlet, 12. Liquid phase outlet, 2. Cooling coil, 3. Gas-liquid separation tank, 4. First circulating pump, 5. Primary condenser, 6. Second circulating pump, 71. First-stage gas-liquid separation tank, 72. Second-stage condenser, 73. Second-stage gas-liquid separation tank, 74. Third-stage condenser, 75. Third-stage gas-liquid separation tank, 76. Fourth-stage condenser, 77. Fourth-stage gas-liquid separation tank, 771. Pressure control valve, 78. Acid water tank. DETAILED DESCRIPTION

[0019] The technical scheme of the utility model will be described below in connection with the drawings, obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the scope of the utility model protection.

[0020] In the description of the utility model, it is necessary to explain that the orientation or position relation indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is the orientation or position relation shown in the drawing, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it can not be understood as the limitation of the utility model. In addition, the terms "first", "second", "third" are only for the description purpose, and can not be understood as indicating or implying relative importance.

[0021] In the description of the utility model, it is necessary to explain, unless another explicit provision and limitation, term "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected, can be mechanical connection, also can be electrical connection, can be direct connection, also can through the intermediate medium indirectly connect, can be two element internal communication. For ordinary skilled in the art, the above-mentioned terms can be understood in the specific meaning in the utility model according to specific circumstances. In addition, the technical features involved in the different embodiments of the utility model described below can be combined as long as they do not conflict with each other.

[0022] Example 1

[0023] As shown in the figure, the toluene oxidation reactor 1 is provided with a condensing coil 2, one end of the condensing coil 2 is connected with the water outlet of the gas-liquid separation tank 3, the other end is connected with the liquid return port of the gas-liquid separation tank 3 through the first circulating pump 4, the gas phase outlet 11 at the top of the toluene oxidation reactor 1 is connected with the primary condenser 5, the primary condenser 5 is connected with the gas-liquid separation tank 3 through the second circulating pump 6 for liquid circulation, the toluene oxidation reactor 1 is provided with a liquid inlet at one side of the lower end, the toluene and the catalyst used in the reaction are sent into the tank from the liquid inlet, the toluene oxidation reactor is provided with an air inlet at the bottom, hot compressed air is transported into the toluene oxidation reactor from the air inlet, and the toluene oxidation reactor 1 is provided with a liquid phase outlet 12 at one side of the upper end, which is connected with the rectification section to rectify the liquid phase product,

[0024] The primary condenser 5 is connected with the first-stage gas-liquid separation tank 71 in the multi-stage condensing separation and recovery assembly, the liquid outlet of the first-stage gas-liquid separation tank 71 is connected with the liquid inlet of the toluene oxidation reactor 1, the top gas outlet of the first-stage gas-liquid separation tank 71 is connected with the secondary condenser 72, the secondary condenser 72 is connected with the second-stage gas-liquid separation tank 73, the top gas outlet of the second-stage gas-liquid separation tank 73 is sequentially connected with the third-stage condenser 74, the third-stage gas-liquid separation tank 75, the fourth-stage condenser 76 and the fourth-stage gas-liquid separation tank 77, wherein the liquid outlets of the second-stage gas-liquid separation tank 73, the third-stage gas-liquid separation tank 75 and the fourth-stage gas-liquid separation tank 77 are all connected with the acid water tank 78 through pipelines, the upper separation outlet of the acid water tank 78 is connected with the liquid inlet of the toluene oxidation reactor 1 through a pipeline, and the lower separation outlet of the acid water tank 78 is connected with the sewage treatment equipment, so that the wastewater in the lower layer of the acid water tank 78 is sent to the sewage treatment equipment, and the secondary condenser 72, the third-stage condenser 74 and the fourth-stage condenser 76 in the multi-stage condensing separation and recovery assembly are all connected with the water circulation cooling equipment in industrial production,

[0025] Specifically, the top gas outlet of the fourth gas-liquid separation tank 77 is provided with a pressure control valve 771, the valve rear pressure is 0.45MPa nitrogen gas which is delivered to the tail gas refrigeration generator set, and the energy of the power generation recovery residual pressure is recovered.

[0026] Example 2

[0027] In the production process, hot compressed air is introduced into the bottom of the toluene oxidation reactor 1 from the air compression station, toluene, catalyst and air delivered therein are fully mixed in the toluene oxidation reactor 1 from the bottom to the top, and benzoic acid is generated under the conditions of a reaction temperature of 158-174 DEG C and a reaction pressure of 0.49-0.6 MPa.

[0028] The liquid phase product in the reaction is a mixture of benzoic acid, excess unreacted toluene, a small amount of by-product benzaldehyde and benzyl benzoate, which is taken out from the upper side liquid outlet 12 of the toluene oxidation reactor 1 and delivered to the downstream rectification section for treatment, and the gas phase product output from the top of the toluene oxidation reactor 1 is a mixture of residual nitrogen in air, reaction generated water vapor, part of evaporated toluene and a small amount of benzoic acid, which enters the primary condenser 5 through the top gas phase outlet 11 for cooling and recovering part of the condensable gas,

[0029] The toluene oxidation reaction is an exothermic reaction process, six cooling coils 2 are arranged on the toluene oxidation reactor 1, the cooling coils 2 are connected with the gas-liquid separation tank 3, 130-152 DEG C water in the vapor-liquid separation tank is delivered to the cooling coils 2 by the first circulating pump 4 for circulating heat exchange and cooling, the reaction heat in the reactor is taken away back to the vapor-liquid separation tank to generate 0.2-0.4 MPa saturated steam for production use, and the gas phase product output from the top gas phase outlet 11 of the toluene oxidation reactor first enters the primary condenser 5, and the 130-152 DEG C hot water in the vapor-liquid separation tank 3 is delivered to the condenser 5 by the second circulating pump 6, and after heat exchange with the gas phase product, it returns to the vapor-liquid separation tank 3 to generate 0.2-0.4 MPa saturated steam for production use, thereby improving the heat utilization efficiency in production;

[0030] The gas-liquid mixture cooled down by the primary condenser pipe 5 enters a primary gas-liquid separation tank 71 to be separated, the separated liquid directly flows back to the toluene oxidation reactor 1, and the gas enters a secondary condenser 72 to be cooled by hot water at 65℃, the gas-liquid mixture cooled down enters a secondary gas-liquid separation tank 73 to be separated, the liquid flows into an acid water tank 78 to be treated by layering; the gas separated by the secondary gas-liquid separation tank 73 enters a tertiary condenser 74 to be cooled by circulating water at normal temperature, the gas-liquid mixture cooled down enters a tertiary gas-liquid separation tank 75 to be separated, the liquid flows into the acid water tank 78 to be treated by layering; the gas separated by the tertiary gas-liquid separation tank 75 enters a quaternary condenser 76 to be cooled by circulating water at normal temperature, the gas-liquid mixture cooled down enters a quaternary gas-liquid separation tank 77 to be separated, the liquid flows into the acid water tank 78 to be treated by layering, the toluene in the upper layer of the acid water tank 78 directly flows back to the toluene oxidation reactor 1, greatly improving the utilization rate of material resources and reducing material waste.

[0031] The basic principle and main features of the present application and the advantages of the present application are shown and described above. The various components mentioned in the present application are common techniques in the prior art, which should be understood by those skilled in the art. The present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A toluene oxidation reaction apparatus, characterized in that... The application relates to a toluene oxidation reactor, a cooling coil, a gas-liquid separation tank, a primary condenser, a multi-stage condensing separation and recovery assembly, a first circulating pump and a second circulating pump, wherein the toluene oxidation reactor is provided with a condensing coil, one end of the condensing coil is connected with a water outlet of the gas-liquid separation tank, the other end of the condensing coil is connected with a liquid return port of the gas-liquid separation tank through the first circulating pump, a gas phase outlet at the top of the toluene oxidation reactor is connected with the primary condenser, the primary condenser is connected with the water outlet of the gas-liquid separation tank through the second circulating pump, a water outlet of the primary condenser is connected with the liquid return port of the gas-liquid separation tank, and the primary condenser is connected with the multi-stage condensing separation and recovery assembly.

2. The toluene oxidation reaction apparatus according to claim 1, characterized by The multi-stage condensing separation and recovery assembly is composed of a primary gas-liquid separation tank, a secondary condenser, a secondary gas-liquid separation tank, a tertiary condenser, a tertiary gas-liquid separation tank, a quaternary condenser, a quaternary gas-liquid separation tank and an acid water tank, the primary gas-liquid separation tank is connected with the primary condenser, a liquid outlet of the primary gas-liquid separation tank is connected with a liquid inlet of the toluene oxidation reactor, a gas outlet at the top of the primary gas-liquid separation tank is connected with the secondary condenser, the secondary condenser is connected with the secondary gas-liquid separation tank, a gas outlet at the top of the secondary gas-liquid separation tank is sequentially connected with the tertiary condenser, the tertiary gas-liquid separation tank, the quaternary condenser and the quaternary gas-liquid separation tank, a liquid outlet of the secondary gas-liquid separation tank, a liquid outlet of the tertiary gas-liquid separation tank and a liquid outlet of the quaternary gas-liquid separation tank are all connected with the acid water tank through pipelines, and an upper separation outlet of the acid water tank is connected with the liquid inlet of the toluene oxidation reactor through a pipeline.

3. The toluene oxidation reaction apparatus according to claim 2, characterized by A pressure control valve is arranged at the gas outlet at the top of the quaternary gas-liquid separation tank.

4. The toluene oxidation reaction apparatus according to claim 2, characterized by The secondary condenser, the tertiary condenser and the quaternary condenser are all connected with water circulating cooling equipment.

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