Gas-liquid separation device of cyclohexane catalytic oxidation method oxidation liquid separation system

Abstract

A gas-liquid separation device of a cyclohexane catalytic oxidation method oxidation liquid separation system comprises a flash tank, a liquid separation tank, an extraction washing tower and a flash tower, a top outlet of the flash tank supplies materials to the flash tower, an overflow port is arranged to supply materials to the liquid separation tank, and a bottom outlet is used for supplying materials to a rectification system. A light phase outlet of the liquid separation tank supplies materials to the extraction washing tower, a heavy phase outlet of the liquid separation tank supplies materials to the rectification system, a water source inlet is formed in the top of the extraction washing tower, a bottom outlet of the extraction washing tower supplies materials to the flash evaporation tank, and a top outlet of the extraction washing tower is used for supplying materials to the rectification system; a light phase outlet of the return tank returns to the flash tower and is partially discharged, a heavy phase outlet of the return tank supplies materials to the flash tower, and a bottom outlet of the flash tower supplies materials to the flash tank. On the basis of low-energy-consumption and high-yield separation of oxidation liquid prepared by a cyclohexane catalytic oxidation method, the system can be effectively prevented from being blocked, and long-time normal work of the system is ensured.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, in particular to a gas-liquid separation device of an oxidation liquid separation system of a cyclohexane catalytic oxidation method. Background Art

[0002] Cyclohexane oxidation is the main method used in the production of adipic acid in the world. The world's major adipic acid manufacturers, including DuPont, Monsanto and Rhodia in France, all use this process technology. The main advantages of cyclohexane oxidation are mature technology, complete localization of catalysts and chemicals, high product yield and purity, but the process is complicated and requires a large amount of nitric acid. At present, there are two oxidation process routes for cyclohexane liquid phase oxidation in industrial production, one is a non-catalytic oxidation process and the other is a catalytic oxidation process. The catalytic oxidation process mainly uses cobalt salts, boric acid or metaboric acid as catalysts, and oxygen and cyclohexane react under the action of cobalt salt catalysts.

[0003] At present, the oxidizing liquid prepared by the cyclohexane catalytic oxidation method is usually separated and purified through the processes of oxidizing liquid decomposition system, waste alkali liquid separation system, waste alkali liquid flash tower system, alkane distillation system (five towers), and alcohol ketone refining (three towers). The overall energy consumption of the system is high, the yield of separated alcohol ketone dibasic acid esters is not ideal, and it is easy to cause blockage of the separation system.

[0004] Therefore, how to separate the oxidation liquid prepared by the cyclohexane catalytic oxidation method with low energy consumption and high yield is a problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The utility model aims to address the deficiencies in the prior art and to provide a gas-liquid separation device for an oxidation liquid separation system of a cyclohexane catalytic oxidation method, which can effectively avoid system blockage and ensure long-term normal operation of the system on the basis of low energy consumption and high yield separation of the oxidation liquid prepared by the cyclohexane catalytic oxidation method.

[0006] The technical solution to achieve the purpose of this utility model is:

[0007] A gas-liquid separation device of an oxidation liquid separation system of a cyclohexane catalytic oxidation method comprises a flash tank, a separator tank, an extraction washing tower and a flash tower. The feed port of the flash tank is connected to an oxidation liquid source, the top outlet of the flash tank supplies the flash tower, the flash tank is provided with an overflow port to supply the separator tank, the bottom outlet of the flash tank is used to supply a distillation system, the light phase outlet of the separator tank supplies the extraction washing tower, the heavy phase outlet of the separator tank is used to supply the distillation system, a water source inlet is provided at the top of the extraction washing tower, the bottom outlet of the extraction washing tower supplies the flash tank, the top outlet of the extraction washing tower is used to supply the distillation system, the top outlet of the flash tower is connected to a reflux tank via a condenser, the light phase outlet of the reflux tank refluxes to the flash tower and is partially discharged, the heavy phase outlet of the reflux tank supplies the flash tank, and the bottom outlet of the flash tower supplies the flash tank.

[0008] The top outlet of the separator tank supplies materials to the flash tower.

[0009] The light phase outlet of the liquid separator is self-circulated and partially extracted to feed the extraction washing tower.

[0010] The light phase outlet of the reflux tank is self-circulated and partially refluxed to the flash tower and partially discharged, and the heavy phase outlet of the reflux tank is self-circulated and partially extracted to feed the flash tank.

[0011] The above technical solution has the following beneficial effects:

[0012] 1. The utility model utilizes the heat of the oxidation liquid itself to first perform primary flash evaporation and secondary flash evaporation, so that most of the cyclohexane in the oxidation liquid is vaporized, and separated after condensation, thereby reducing the energy consumption of the oxidation liquid separation and ensuring that the purity of the separated cyclohexane meets the requirements of reuse. By setting a water source inlet in the extraction washing tower, it is used to extract and wash the high-concentration oil phase (mainly alkanol ketone dibasic acid ester), wash the dibasic acid ester therein into the water phase, avoid the dibasic acid ester in the oil phase being brought into the distillation system to cause blockage, and ensure the long-term normal operation of the supporting distillation system.

[0013] 2. In the utility model, the light phase of the liquid separator is circulated and partially extracted to feed the extraction washing tower, thereby improving the purity of the light phase sent to the extraction washing tower, and the extraction flow rate can be selected according to actual needs; the light phase and heavy phase of the reflux tank are both circulated and partially extracted, the purity of the light phase is reduced and the load of the flash tank is reduced, and the extraction flow rate can be selected according to actual needs.

[0014] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a connection diagram of the utility model.

[0016] In the accompanying drawings, 1 is a flash tank, 2 is a liquid separation tank, 3 is an extraction washing tower, 31 is a water source inlet, 4 is a flash tower, and 7 is a reflux tank. DETAILED DESCRIPTION

[0017] Example 1

[0018] See also Figure 1 The gas-liquid separation device of the oxidation liquid separation system of the cyclohexane catalytic oxidation method includes a flash tank 1, a separator tank 2, an extraction washing tower 3, and a flash tower 4. The feed port of the flash tank 1 is connected to the oxidation liquid source. Usually, a buffer tank needs to be set upstream of the feed port. The top outlet of the flash tank 1 supplies the flash tower 4, and the feed interface is located at the lower part of the side wall of the flash tower. The flash tank 1 is provided with an overflow port to supply the separator tank 2, and the bottom outlet of the flash tank 1 supplies the matching distillation system. The light phase outlet of the separator tank 2 feeds the extraction washing tower 3, and the heavy phase outlet of the separator tank 2 feeds the supporting distillation system. In this embodiment, the top outlet of the separator tank 2 feeds the flash tower 4, that is, the gas phase material is directly sent to the flash tower, and the light phase outlet of the separator tank 2 self-circulates and partially withdraws to feed the extraction washing tower 3. Usually, a pump body and a valve body are arranged on the self-circulation pipeline, and the valve body is arranged downstream of the pump body, and a connecting pipeline is arranged between the pump body and the valve body to feed the extraction washing tower. A water source inlet 31 is arranged at the top of the extraction washing tower 3, and the bottom outlet of the extraction washing tower 3 feeds the flash tank 1, and the top outlet of the extraction washing tower 3 feeds the supporting distillation system. The top outlet of the flash tower 4 is connected to the reflux tank 7 via a condenser, and the light phase outlet of the reflux tank 7 refluxes to the flash tower and discharges cyclohexane. Specifically, the light phase outlet of the reflux tank 7 circulates and partially refluxes to the flash tower 4 and discharges cyclohexane. The heavy phase outlet of the reflux tank 7 feeds the flash tank 1. Specifically, the heavy phase outlet of the reflux tank 7 circulates and partially withdraws and feeds the flash tank 1. The bottom outlet of the flash tower 4 feeds the flash tank 1.

[0019] The working principle of the utility model is:

[0020] 1) The oxidized liquid obtained by the cyclohexane catalytic oxidation method is sent to a flash tank, and the gas phase obtained by flash evaporation enters a flash tower. The temperature of the oxidized liquid is usually 140-145°C. The oil phase in the flash tank overflows into a separator tank, and the water phase (bottom heavy phase) in the flash tank is sent to a matching distillation system;

[0021] 2) The oil phase in the separator tank is separated into layers, the light phase is sent to the extraction and washing tower, and the heavy phase is sent to the supporting distillation system;

[0022] 3) The light phase entering the extraction washing tower is extracted with the water sent into the extraction washing tower, and the oil phase obtained by extraction is sent to the supporting distillation system (discharged from the top of the extraction washing tower), and the water phase obtained by extraction (discharged from the bottom) is sent to the flash tank;

[0023] 4) The gas phase entering the flash tower transfers mass and heat with the reflux liquid at the top. The gas phase at the top of the tower is condensed and sent to the reflux tank for stratification. The light phase refluxes to the flash tower and is partially discharged to obtain cyclohexane, and the heavy phase is sent to the flash tank.

[0024] The components sent to the distillation system are further separated to obtain alcohol ketone dibasic acid esters, in which the cyclohexane content is less than 0.002%.

Claims

1. A gas-liquid separation device for an oxidation liquid separation system of cyclohexane catalytic oxidation, characterized in that: It comprises a flash tank (1), a liquid separation tank (2), an extraction washing tower (3), and a flash tower (4). The feed inlet of the flash tank (1) is connected to the oxidizing liquid source, the top outlet of the flash tank (1) supplies the flash tower (4), the flash tank (1) is provided with an overflow port to supply the separator tank (2), and the bottom outlet of the flash tank (1) is used to supply the distillation system. The light phase outlet of the separator tank (2) is used to supply the extraction washing tower (3), and the heavy phase outlet of the separator tank (2) is used to supply the distillation system. A water source inlet (31) is arranged at the top of the extraction washing tower (3), the bottom outlet of the extraction washing tower (3) supplies materials to the flash tank (1), and the top outlet of the extraction washing tower (3) is used to supply materials to the distillation system. The top outlet of the flash tower (4) is connected to the reflux tank (7) via a condenser, the light phase outlet of the reflux tank (7) refluxes to the flash tower and is partially discharged, the heavy phase outlet of the reflux tank (7) supplies the flash tank (1), and the bottom outlet of the flash tower (4) supplies the flash tank (1).

2. The gas-liquid separation device of the cyclohexane catalytic oxidation method oxidation liquid separation system according to claim 1 is characterized in that: The top outlet of the liquid separator (2) supplies material to the flash tower (4).

3. The gas-liquid separation device of the cyclohexane catalytic oxidation method oxidation liquid separation system according to claim 1 is characterized in that: The light phase outlet of the liquid separation tank (2) is self-circulated and partially extracted to supply the extraction washing tower (3).

4. The gas-liquid separation device of the cyclohexane catalytic oxidation method oxidation liquid separation system according to claim 1 is characterized in that: The light phase outlet of the reflux tank (7) is self-circulated and partially refluxed to the flash tower (4) and partially discharged, and the heavy phase outlet of the reflux tank (7) is self-circulated and partially extracted to feed the flash tank (1).

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