Methanol rectification system capable of increasing methanol yield

Abstract

The utility model discloses a methanol rectification system capable of improving methanol yield, which is characterized by comprising a crude methanol preheater, a pre-rectification tower, a pre-prognosis methanol pump, a pressurizing tower inlet preheater, a pressurizing tower, an atmospheric tower, an atmospheric tower condenser, an atmospheric tower reflux tank, an atmospheric tower product cooler and a methanol storage tank, and the cold medium outlet of the pressurizing tower inlet preheater is also communicated with the feeding hole of the atmospheric tower through a pipeline. The method has the advantages that in the start-up process, tower bottoms in the pre-rectifying tower are heated by the tower inlet preheater of the pressurizing tower and are supplied to the pressurizing tower and the atmospheric tower respectively, so that the time required for establishing the liquid level of the atmospheric tower can be shortened, the start-up time of the system is shortened, the output time of refined methanol is prolonged, and finally the yield of methanol is increased; the heat carried by the steam discharged from the top of the pressurizing tower can be recycled, and the methanol carried by the steam can be recovered, so that the yield of the methanol is increased.

Description

Technical field:

[0001] The utility model relates to a methanol distillation system, in particular to a methanol distillation system capable of increasing methanol output. Background technology:

[0002] At present, in the process of preparing methanol, crude methanol is usually distilled and purified through a pre-distillation tower, a pressure distillation tower and an atmospheric distillation tower. However, during the start-up process, it is necessary to establish the liquid level of the pre-distillation tower, the pressure distillation tower and the atmospheric distillation tower. Since the liquid level of the pressure distillation tower is established from the pre-distillation tower's post-pump, and the liquid level of the atmospheric distillation tower is from the pressure distillation tower. Only when the pressure of the pressure distillation tower reaches a certain value can liquid be sent to the atmospheric distillation tower, resulting in a long time for the atmospheric distillation tower to establish the liquid level, which seriously affects the start-up time of the distillation system, shortens the output time of refined methanol, and leads to low annual production of methanol. Utility model content:

[0003] In order to solve the above problems, the utility model aims to provide a methanol distillation system which can increase the methanol production.

[0004] The utility model is implemented by the following technical solutions:

[0005] A methanol distillation system capable of increasing methanol production comprises a crude methanol preheater, a pre-distillation tower, a post-distillation methanol pump, a pressurized tower inlet preheater, a pressurized tower, an atmospheric tower, an atmospheric tower condenser, an atmospheric tower reflux tank, an atmospheric tower product cooler and a methanol storage tank;

[0006] The gas outlet end of the crude methanol pipeline is connected to the cold medium inlet of the crude methanol preheater, the cold medium outlet of the crude methanol preheater is connected to the feed port of the pre-distillation tower through a pipeline, the bottom liquid outlet of the pre-distillation tower is connected to the inlet of the post-distillation methanol pump through a pipeline, the outlet of the post-distillation methanol pump is connected to the cold medium inlet of the pressurized tower inlet preheater through a pipeline, the cold medium outlet of the pressurized tower inlet preheater is connected to the feed port of the pressurized tower through a pipeline, the bottom liquid outlet of the pressurized tower is connected to the hot medium inlet of the pressurized tower inlet preheater through a pipeline, and the pressurized tower inlet preheater is connected to the hot medium inlet of the pressurized tower inlet preheater. The heat medium outlet of the reactor is communicated with the feed inlet of the atmospheric tower through a pipeline, the top steam outlet of the atmospheric tower is communicated with the inlet of the atmospheric tower condenser through a pipeline, the outlet of the atmospheric tower condenser is communicated with the inlet of the atmospheric tower reflux tank through a pipeline, the discharge port of the atmospheric tower reflux tank is communicated with the inlet of the atmospheric tower reflux pump through a pipeline, the outlet of the atmospheric tower reflux pump is divided into two paths, one path is communicated with the feed inlet of the atmospheric tower through a pipeline, and the other path is communicated with the inlet of the atmospheric tower product cooler through a pipeline, and the outlet of the atmospheric tower product cooler is communicated with the inlet of the methanol storage tank through a pipeline;

[0007] The cold medium outlet of the preheater entering the pressure tower is also connected to the feed inlet of the atmospheric pressure tower through a pipeline.

[0008] Further, it also includes a pre-tower reboiler, a pressure tower reboiler and an atmospheric tower reboiler;

[0009] The bottom liquid outlet of the pre-distillation tower is also connected to the inlet of the pre-tower reboiler through a pipeline, and the outlet of the pre-tower reboiler is connected to the lower part of the pre-distillation tower through a pipeline;

[0010] The bottom liquid outlet of the pressurized tower is also connected to the inlet of the pressurized tower reboiler through a pipeline, and the outlet of the pressurized tower reboiler is connected to the lower part of the pressurized tower through a pipeline;

[0011] The bottom liquid outlet of the atmospheric tower is also connected to the cold medium inlet of the atmospheric tower reboiler through a pipeline, and the cold medium inlet of the atmospheric tower reboiler is connected to the lower part of the atmospheric tower through a pipeline; the top steam outlet of the pressurized tower is connected to the hot medium inlet of the atmospheric tower reboiler through a pipeline, and the hot medium outlet of the atmospheric tower reboiler is connected to the inlet of the pressurized tower reflux tank through a pipeline, and the outlet of the pressurized tower reflux tank is connected to the inlet of the pressurized tower reflux pump through a pipeline, and the outlet of the pressurized tower reflux pump is connected to the feed port of the pressurized tower through a pipeline.

[0012] Furthermore, the exhaust port of the atmospheric tower reflux tank is connected to the inlet of the atmospheric tower exhaust condenser through a pipeline, and the liquid phase outlet of the atmospheric tower exhaust condenser is connected to the inlet of the atmospheric tower reflux tank through a pipeline.

[0013] Advantages of the utility model:

[0014] 1. During the start-up process, the bottom liquid in the pre-distillation tower is heated up by the preheater of the pressure tower to supply liquid to the pressure tower and the atmospheric tower respectively, thereby shortening the time required to establish the liquid level of the atmospheric tower, thereby shortening the start-up time of the system, and extending the output time of refined methanol, and finally achieving an increase in the output of methanol.

[0015] 2. The steam from the top of the pressure tower is used as a heat medium to enter the reboiler of the atmospheric tower to provide heat for the reboiling of the bottom liquid of the atmospheric tower, thereby realizing heat recycling. In addition, part of the methanol carried will be condensed after heat exchange and cooling, and enter the reflux tank of the pressure tower and re-enter the pressure tower for distillation. In this way, the methanol carried in the steam from the top of the tower can be recovered, thereby increasing the methanol production. Description of the drawings:

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 Schematic diagram of system connection of this embodiment.

[0018] In the figure: crude methanol pipeline 1, crude methanol preheater 2, pre-distillation tower 3, pre-methanol pump 4, pressure tower inlet preheater 5, pressure tower 6, atmospheric tower 7, atmospheric tower condenser 8, atmospheric tower reflux tank 9, atmospheric tower product cooler 10, methanol storage tank 11, pre-tower reboiler 12, pressure tower reboiler 13, atmospheric tower reboiler 14, pressure tower reflux tank 15, pressure tower reflux pump 16, atmospheric tower exhaust condenser 17, atmospheric tower reflux pump 18. Specific implementation method:

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] Embodiment 1:

[0021] like Figure 1 A methanol distillation system for increasing methanol production is shown, comprising a crude methanol preheater 2, a pre-distillation tower 3, a post-distillation methanol pump 4, a pressurized tower inlet preheater 5, a pressurized tower 6, an atmospheric tower 7, an atmospheric tower condenser 8, an atmospheric tower reflux tank 9, an atmospheric tower product cooler 10 and a methanol storage tank 11;

[0022] The gas outlet end of the crude methanol pipeline 1 is connected to the cold medium inlet of the crude methanol preheater 2, the cold medium outlet of the crude methanol preheater 2 is connected to the feed port of the pre-distillation tower 3 through a pipeline, the tower bottom liquid outlet of the pre-distillation tower 3 is connected to the inlet of the pre-distillation methanol pump 4 through a pipeline, the outlet of the pre-distillation methanol pump 4 is connected to the cold medium inlet of the pressure tower inlet preheater 5 through a pipeline, the cold medium outlet of the pressure tower inlet preheater 5 is connected to the feed port of the pressure tower 6 through a pipeline, the tower bottom liquid outlet of the pressure tower 6 is connected to the hot medium inlet of the pressure tower inlet preheater 5 through a pipeline, and the hot medium outlet of the pressure tower inlet preheater 5 is connected to the feed port of the atmospheric pressure tower 7 through a pipeline. The top steam outlet of the atmospheric tower 7 is connected with the inlet of the atmospheric tower condenser 8 through a pipeline, the outlet of the atmospheric tower condenser 8 is connected with the inlet of the atmospheric tower reflux tank 9 through a pipeline, the discharge port of the atmospheric tower reflux tank 9 is connected with the inlet of the atmospheric tower reflux pump 18 through a pipeline, the outlet of the atmospheric tower reflux pump 18 is divided into two paths, one path is connected with the feed port of the atmospheric tower 7 through a pipeline, and the other path is connected with the inlet of the atmospheric tower product cooler 10 through a pipeline, and the outlet of the atmospheric tower product cooler 10 is connected with the inlet of the methanol storage tank 11 through a pipeline; the cold medium outlet of the pressure tower inlet preheater 5 is also connected with the feed port of the atmospheric tower 7 through a pipeline.

[0023] The present embodiment further comprises a pre-tower reboiler 12, a pressure tower reboiler 13 and an atmospheric tower reboiler 14; the tower bottom liquid outlet of the pre-distillation tower 3 is also connected to the inlet of the pre-tower reboiler 12 through a pipeline, and the outlet of the pre-tower reboiler 12 is connected to the lower part of the pre-distillation tower 3 through a pipeline; the tower bottom liquid outlet of the pressure tower 6 is also connected to the inlet of the pressure tower reboiler 13 through a pipeline, and the outlet of the pressure tower reboiler 13 is connected to the lower part of the pressure tower 6 through a pipeline; the tower bottom liquid outlet of the atmospheric tower 7 is also connected to the atmospheric tower 7 through a pipeline. The cold medium inlet of the reboiler 14 is connected, and the cold medium inlet of the atmospheric tower reboiler 14 is connected to the lower part of the atmospheric tower 7 through a pipeline; the top steam outlet of the pressure tower 6 is connected to the hot medium inlet of the atmospheric tower reboiler 14 through a pipeline, and the hot medium outlet of the atmospheric tower reboiler 14 is connected to the inlet of the pressure tower reflux tank 15 through a pipeline, and the outlet of the pressure tower reflux tank 15 is connected to the inlet of the pressure tower reflux pump 16 through a pipeline, and the outlet of the pressure tower reflux pump 16 is connected to the feed port of the pressure tower 6 through a pipeline.

[0024] The exhaust port of the atmospheric tower reflux tank 9 is connected to the inlet of the atmospheric tower exhaust condenser 17 through a pipeline, and the liquid phase outlet of the atmospheric tower exhaust condenser is connected to the inlet of the atmospheric tower reflux tank 9 through a pipeline.

[0025] Job Description:

[0026] The crude methanol produced in the synthesis section is preheated by the crude methanol preheater 2 and first enters the pre-distillation tower 3 to remove some light components. The bottom liquid enters the pressure tower inlet preheater 5 to heat up and then enters the pressure tower 6 to further remove light components. It is then discharged from the bottom of the pressure tower 6 and enters the pressure tower inlet preheater 5 as a heat medium to exchange heat with the bottom liquid of the pre-distillation tower 3 entering the pressure tower 6. After heat exchange, the bottom liquid of the pressure tower 6 enters the atmospheric pressure tower 7, and the methanol enters the atmospheric pressure tower condenser 8 with the top steam to cool and condense, and then enters the atmospheric pressure tower reflux tank 9. After that, a part of it returns to the atmospheric pressure tower 7, and a part of it is cooled in the atmospheric pressure tower product cooler 10 and passes the inspection and enters the methanol storage tank 11 for temporary storage.

[0027] In this embodiment, in order to solve the problem that the atmospheric distillation tower takes too long to establish the liquid level during the system startup process, the cold medium outlet of the pressure tower inlet preheater 5 is also connected to the feed port of the atmospheric tower 7 through a pipeline. In this way, during the startup process, the tower bottom liquid in the pre-distillation tower 3 enters the tower preheater 5 through the pressure tower 6 to increase the temperature and supply liquid to the pressure tower 6 and the atmospheric tower 7 respectively, thereby shortening the time required for the atmospheric tower 7 to establish the liquid level, thereby shortening the system startup time, thereby extending the output time of refined methanol, and finally achieving an increase in the output of methanol.

[0028] At the same time, since the top steam of the pressurized tower 6 also carries some methanol and a large amount of heat, in the present embodiment, the top steam of the pressurized tower 6 is used as a heat medium to enter the atmospheric tower reboiler 14 to provide heat for the reboiling of the bottom liquid of the atmospheric tower 7, thereby realizing heat recycling, and part of the methanol carried will be condensed after heat exchange and cooling, enter the pressurized tower reflux tank 15, and re-enter the pressurized tower 6 for distillation, so that the methanol carried in the top steam can be recovered, thereby increasing the methanol production.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A methanol distillation system capable of increasing methanol production, characterized in that: It includes a crude methanol preheater, a pre-distillation tower, a post-distillation methanol pump, a pressure tower inlet preheater, a pressure tower, an atmospheric tower, an atmospheric tower condenser, an atmospheric tower reflux tank, an atmospheric tower product cooler and a methanol storage tank; The gas outlet end of the crude methanol pipeline is connected to the cold medium inlet of the crude methanol preheater, the cold medium outlet of the crude methanol preheater is connected to the feed port of the pre-distillation tower through a pipeline, the bottom liquid outlet of the pre-distillation tower is connected to the inlet of the post-distillation methanol pump through a pipeline, the outlet of the post-distillation methanol pump is connected to the cold medium inlet of the pressurized tower inlet preheater through a pipeline, the cold medium outlet of the pressurized tower inlet preheater is connected to the feed port of the pressurized tower through a pipeline, the bottom liquid outlet of the pressurized tower is connected to the hot medium inlet of the pressurized tower inlet preheater through a pipeline, and the pressurized tower inlet preheater is connected to the hot medium inlet of the pressurized tower inlet preheater. The heat medium outlet of the reactor is communicated with the feed inlet of the atmospheric tower through a pipeline, the top steam outlet of the atmospheric tower is communicated with the inlet of the atmospheric tower condenser through a pipeline, the outlet of the atmospheric tower condenser is communicated with the inlet of the atmospheric tower reflux tank through a pipeline, the discharge port of the atmospheric tower reflux tank is communicated with the inlet of the atmospheric tower reflux pump through a pipeline, the outlet of the atmospheric tower reflux pump is divided into two paths, one path is communicated with the feed inlet of the atmospheric tower through a pipeline, and the other path is communicated with the inlet of the atmospheric tower product cooler through a pipeline, and the outlet of the atmospheric tower product cooler is communicated with the inlet of the methanol storage tank through a pipeline; The cold medium outlet of the preheater entering the pressure tower is also connected to the feed inlet of the atmospheric pressure tower through a pipeline.

2. A methanol distillation system capable of increasing methanol production according to claim 1, characterized in that: It also includes a pre-tower reboiler, a pressurized tower reboiler and an atmospheric tower reboiler; The bottom liquid outlet of the pre-distillation tower is also connected to the inlet of the pre-tower reboiler through a pipeline, and the outlet of the pre-tower reboiler is connected to the lower part of the pre-distillation tower through a pipeline; The bottom liquid outlet of the pressurized tower is also connected to the inlet of the pressurized tower reboiler through a pipeline, and the outlet of the pressurized tower reboiler is connected to the lower part of the pressurized tower through a pipeline; The bottom liquid outlet of the atmospheric tower is also connected to the cold medium inlet of the atmospheric tower reboiler through a pipeline, and the cold medium inlet of the atmospheric tower reboiler is connected to the lower part of the atmospheric tower through a pipeline; the top steam outlet of the pressurized tower is connected to the hot medium inlet of the atmospheric tower reboiler through a pipeline, and the hot medium outlet of the atmospheric tower reboiler is connected to the inlet of the pressurized tower reflux tank through a pipeline, and the outlet of the pressurized tower reflux tank is connected to the inlet of the pressurized tower reflux pump through a pipeline, and the outlet of the pressurized tower reflux pump is connected to the feed port of the pressurized tower through a pipeline.

3. A methanol distillation system capable of increasing methanol production according to claim 1, characterized in that: The exhaust port of the atmospheric tower reflux tank is connected to the inlet of the atmospheric tower exhaust condenser through a pipeline, and the liquid phase outlet of the atmospheric tower exhaust condenser is connected to the inlet of the atmospheric tower reflux tank through a pipeline.

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