Hydrogen recovery pretreatment system of PTA (pure terephthalic acid) device

Abstract

The utility model discloses a hydrogen recovery pretreatment system of a pure terephthalic acid (PTA) device, which belongs to the technical field of tail gas treatment equipment and comprises a tail gas heat exchanger, an alkaline washing tower, an alkali liquor pump a, an alkali liquor pump b, a circulating alkali liquor cooler, a water washing tower, a demineralized water tank, a circulating pump a, a circulating pump b and a tail gas vapor-liquid separator. The alkaline washing tower is respectively communicated with an alkaline liquid pump through a pipeline, the alkaline liquid pump is communicated with a circulating alkaline liquid cooler through a pipeline, the circulating alkaline liquid cooler is communicated with the upper part of the alkaline washing tower through a pipeline, the top of the alkaline washing tower is communicated with a water washing tower through a pipeline, and the water washing tower is communicated with a demineralized water tank through a pipeline; the demineralized water tank is communicated with the circulating pump through a pipeline, the circulating pump is communicated with the upper part of the water scrubber through a pipeline, the top of the water scrubber is communicated with the tail gas vapor-liquid separator through a pipeline, the tail gas vapor-liquid separator is connected with the hydrogen purification device through a pipeline, and the hydrogen pretreatment device is mainly applied to hydrogen pretreatment in chemical production.

Description

TECHNICAL FIELD

[0001] The utility model relates to chemical equipment technical field, concretely is a kind of PTA device hydrogen recovery pretreatment system. BACKGROUND

[0002] In PTA refining reactor, due to using excessive hydrogen in reaction process, impurity difficult to separate in material is reduced to more easily removed form. Subsequently, with the aid of separation equipment, it can produce standard-compliant product.

[0003] In this process, a large amount of unreacted hydrogen will carry acidic solid particles together and discharge. After these mixtures are washed in washing tower, they are discharged from discharge port together with nitrogen, resulting in waste of resources. If waste gas is directly sent to hydrogen purification device, it will cause system blockage and cannot continuously operate.

[0004] In order to solve the above technical problems, the applicant has made corresponding modification and redesign to the existing equipment, which can completely solve the above technical problems. UTILITY MODEL CONTENTS

[0005] The utility model is to provide a kind of PTA device hydrogen recovery pretreatment system to solve the problem existing in the above background.

[0006] A kind of PTA device hydrogen recovery pretreatment system, characterized by, including tail gas heat exchanger 1, caustic washing tower, lye pump a, lye pump b, circulating lye cooler, water washing tower, desalted water tank, circulating pump a, circulating pump b and tail gas vapor-liquid separator, tail gas heat exchanger is connected with caustic washing tower by pipeline, the angle of the connected pipeline with horizontal plane is 15 °, the middle part of the pipeline is equipped with reverse spray device, the tail gas heat exchanger 1 includes upper and lower two parts, the upper part is cooler, the lower part is collection tank, tail gas enters from the top head of cooler, is discharged from lower side wall by pipe heat exchange, protective baffle is provided in front of discharge port, caustic washing tower 2 is connected with lye pump a and lye pump b by pipeline respectively, lye pump a and lye pump b are parallel structure, lye pump a and lye pump b are connected with circulating lye cooler by pipeline, circulating lye cooler is used for cooling, circulating lye cooler is connected with the spray lye distributor of caustic washing tower upper part by pipeline, the top of caustic washing tower is connected with water washing tower by pipeline, water washing tower is connected with desalted water tank by pipeline, desalted water tank is connected with circulating pump a and circulating pump b by pipeline, circulating pump a and circulating pump b are also parallel structure, circulating pump a and circulating pump b are connected with the spray water distributor of water washing tower upper part by pipeline, the top of water washing tower is connected with tail gas vapor-liquid separator by pipeline, tail gas vapor-liquid separator is connected with hydrogen purification device by pipeline.

[0007] Preferably: the caustic washing tower comprises two parts, the upper part comprises a packing support tray, packing, packing gland and a spray lye distributor, which is used to evenly spray lye down.

[0008] Preferably: the water washing tower comprises two parts, the upper part comprises a packing support tray, packing, packing gland and a spray water distributor, which is used to evenly spray water down.

[0009] Preferably: the tail gas vapor-liquid separator is internally provided with multiple layers of structured packing.

[0010] Compared with the prior art, the beneficial effects of the utility model are: through the use of the utility model, the particulate matter entrained in the tail gas can be effectively removed, the acidic gas in the tail gas can be neutralized, so that the feeding requirements of the downstream hydrogen gas purification device can be met, and the purposes of energy saving and environmental protection are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is the working principle diagram of the utility model;

[0012] Figure 2 It is the working principle diagram of the utility model; Figure 1 It is the A place local enlarged view of the utility model; DETAILED DESCRIPTION

[0013] The technical schemes in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Apparently, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the person skilled in the art without creative labor are within the protection scope of the utility model.

[0014] Please refer to Figures 1-2 The utility model provides a technical scheme:

[0015] The application relates to a PTA device hydrogen recovery pretreatment system, which comprises a tail gas heat exchanger 1, an alkali washing tower 2, an alkali pump a 3, an alkali pump b 3-1, a circulating alkali cooler 4, a water washing tower 5, a desalted water tank 7, a circulating pump a 8, a circulating pump b 8-1 and a tail gas vapor-liquid separator 6, the tail gas heat exchanger 1 is connected with the alkali washing tower 2 through a pipeline, the connected pipeline forms an angle of 15 DEG with the horizontal plane, a reverse spraying device 9 is arranged in the middle of the pipeline, the alkali washing tower 2 comprises upper and lower parts, the upper part comprises a filler support disc, fillers, a filler gland and a spraying alkali distributor 2-1, the water washing tower 5 comprises upper and lower parts, the upper part comprises a filler support disc, fillers, a filler gland and a spraying water distributor 5-1, the tail gas heat exchanger 1 comprises upper and lower parts, the upper part is a cooler 1-1, and the lower part is a collecting tank 1-2; tail gas enters the top head of the cooler 1-1, is discharged from the lower side wall through heat exchange in the pipe, and a protection baffle is arranged in front of the discharge port; the alkali washing tower 2 is connected with the alkali pump a 3 and the alkali pump b 3-1 through pipelines, the alkali pump a 3 and the alkali pump b 3-1 are connected with the circulating alkali cooler 4 through pipelines, the circulating alkali cooler 4 is connected with the spraying alkali distributor 2-1 in the upper part of the alkali washing tower 2 through a pipeline, the top of the alkali washing tower 2 is connected with the water washing tower 5 through a pipeline, the water washing tower 5 is connected with the desalted water tank 7 through a pipeline, the desalted water tank 7 is connected with the circulating pump a 8 and the circulating pump b 8-1 through pipelines, the circulating pump a 8 and the circulating pump b 8-1 are connected with the spraying water distributor 5-1 in the upper part of the water washing tower 5 through pipelines, the top of the water washing tower 5 is connected with the tail gas vapor-liquid separator 6 through a pipeline, and the tail gas vapor-liquid separator 6 is connected with a hydrogen purification device through a pipeline; the tail gas vapor-liquid separator 6 is internally provided with multiple layers of structured fillers.

[0016] The working principle of the application is as follows:

[0017] During the operation of the device, high-temperature hydrogen-containing tail gas is cooled through the tail gas heat exchanger 1, part of the gas is condensed into liquid, and the entrained materials and the condensed liquid fall into the liquid phase together and are recovered through the system pressure difference;

[0018] The uncondensed gas is transported to the alkali washing tower 2 through a pipeline, the reverse spraying device 9 arranged in the pipeline can wash and recover the entrained materials again. The alkali washing tower 2 is provided with an alkali pump at the bottom, which is used for circulating alkali, and the circulating alkali is cooled through the circulating alkali cooler 4. The tail gas treated through the alkali washing tower 2 to remove acidic impurities is then transported to the water washing tower 5, where a small amount of alkali liquid entrained in the tail gas is adsorbed through desalted water. Finally, the entrained water is recovered through the tail gas vapor-liquid separator 6 and is sent to the hydrogen purification device through a pipeline to recover hydrogen.

[0019] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0020] Although the present application has been described with reference to the embodiments above, it is possible to make various modifications thereto and to replace components thereof with equivalents without departing from the scope of the present application. In particular, each feature disclosed in the embodiments of the present application can be used in combination with any other feature disclosed in the embodiments of the present application, provided that there is no structural conflict. The combinations of features are not exhaustively described in the present specification only for the sake of brevity and resource saving. Therefore, the present application is not limited to the specific embodiments disclosed herein but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A PTA plant hydrogen recovery pretreatment system, characterized in that, The tail gas heat exchanger (1), caustic washing tower (2), caustic soda pump a (3), caustic soda pump b (3-1), circulating caustic soda cooler (4), water washing tower (5), desalted water tank (7), circulating pump a (8), circulating pump b (8-1) and tail gas vapor-liquid separator (6), tail gas heat exchanger (1) is communicated with caustic washing tower (2) through pipeline, the connected pipeline is 15° angle with horizontal plane, the pipeline middle part is equipped with reverse spraying device (9), the tail gas heat exchanger (1) includes upper and lower two parts, the upper part is cooler (1-1), the lower part is collection tank (1-2), tail gas enters from the top head of cooler (1-1), and is discharged from the lower sidewall by heat exchange, caustic washing tower (2) is communicated with caustic soda pump a (3) and caustic soda pump b (3-1) through pipeline respectively, caustic soda pump a (3) and caustic soda pump b (3-1) are communicated with circulating caustic soda cooler (4) through pipeline, circulating caustic soda cooler (4) is communicated with the upper spraying caustic soda distributor (2-1) of caustic washing tower (2) through pipeline, the top of caustic washing tower (2) is communicated with water washing tower (5) through pipeline, water washing tower (5) is communicated with desalted water tank (7) through pipeline, desalted water tank (7) is communicated with circulating pump a (8) and circulating pump b (8-1) through pipeline, circulating pump a (8) and circulating pump b (8-1) are communicated with the upper spraying water distributor (5-1) of water washing tower (5) through pipeline, the top of water washing tower (5) is communicated with tail gas vapor-liquid separator (6) through pipeline, tail gas vapor-liquid separator (6) is connected with hydrogen purification device through pipeline.

2. A PTA plant hydrogen recovery pretreatment system according to claim 1, characterized in that, The caustic washing tower (2) includes upper and lower two parts, and the upper part includes a packing support disc, a packing, a packing gland and a spraying caustic soda distributor (2-1).

3. A PTA plant hydrogen recovery pretreatment system according to claim 1, characterized in that, The water washing tower (5) includes upper and lower two parts, and the upper part includes a packing support disc, a packing, a packing gland and a spraying water distributor (5-1).

4. The PTA plant hydrogen recovery pretreatment system of claim 1, wherein, The tail gas vapor-liquid separator (6) is internally provided with multiple layers of structured packing.

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