Recycling system for methanol synthesis flash steam

Abstract

The utility model discloses a methanol synthesis flash steam recycling system, which comprises a synthesis tower, a methane flash tank, a steam superheater and an absorption tower, the left side surface of the synthesis tower is fixedly communicated with a gas inlet pipe, the right side surface of the synthesis tower is fixedly communicated with a connecting sleeve, the back surface of the connecting sleeve is fixedly communicated with a flow sensing valve, and the flow sensing valve is fixedly communicated with a gas outlet pipe. And the output end of the flow sensing valve is communicated with the methane flash tank through a guide pipe. According to the device, raw material gas is continuously supplied into the synthesis tower through the gas inlet pipe, then crude methanol from the synthesis tower firstly enters the methane flash tank, the methane flash tank is utilized to enable the crude methanol to be subjected to flash evaporation in a reduced pressure environment, flash steam is separated out, and the flash steam enters the absorption tower to be subjected to desalted water washing treatment; the treated non-condensable steam is used as fuel of the steam superheating furnace, so that the non-condensable steam is fully combusted, and finally the non-condensable steam is combusted by the steam superheating furnace and then is conveyed to a fuel gas pipe network, so that energy recovery and reutilization are realized, and the utilization efficiency of the energy is improved.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, in particular to a methanol synthesis flash gas recovery and utilization system. Background Art

[0002] Methanol flash steam is flashed out from the methanol flash tank of the methanol synthesis unit to produce non-condensable steam which is sent to the low-pressure fuel gas pipeline network for use in the steam superheater. As the amount of non-condensable steam in the methanol flash tank increases, it will carry some water vapor from the relaxation gas water scrubber to the steam superheater, causing it to trip. Abnormal fluctuations in the steam superheater will directly affect the temperature of the 4.0 steam pipeline network, as well as the normal operation of the synthesis gas turbine and the carbon dioxide turbine, posing a great threat to the normal and stable production operation of the steam system and the entire unit.

[0003] A Chinese utility model patent application with publication number CN212894507U discloses a methanol gas recovery and utilization system, which relates to the technical field of chemical methanol recovery. The prior art: by setting up multiple methanol flash tanks, and connecting each methanol flash tank to a methanol separation washing tower at the tail end of a corresponding methanol synthesis line, and connecting the flash gas pipelines on each methanol flash tank in parallel to the same flash gas washing tower, the entire recovery system can simultaneously realize methanol gas recovery of crude methanol in multiple methanol synthesis lines;

[0004] The Chinese utility model patent application with publication number CN210885869U discloses a methanol synthesis flash gas recovery device, which relates to the field of tail gas recovery and utilization technology. The prior art: a crude methanol pipe is provided at the inlet of the methanol flash tank, a crude methanol product pipe is provided at the outlet of the methanol flash tank, the top outlet of the methanol flash tank is connected to the inlet of the flash gas washing tower; a deionized water pipe is provided at the upper inlet of the flash gas washing tower, the top outlet of the flash gas washing tower is connected to the fuel gas pipeline network, and the flare pipeline network is connected to the fuel gas pipeline network; the bottom outlet of the flash gas washing tower is connected to the methanol distillation device;

[0005] Both of the above technologies do not make full use of the flash gas after washing, but directly send it to the fuel gas pipeline network and flare system, which not only causes waste of flash gas, but also affects the balance of the fuel gas pipeline network in the later stage. Therefore, we propose a methanol synthesis flash gas recovery and utilization system to solve the above problems. Utility Model Content

[0006] The utility model aims to provide a methanol synthesis flash gas recovery and utilization system to solve the problems raised in the above background technology.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] A methanol synthesis flash gas recovery and utilization system comprises a synthesis tower, a methane flash tank, a steam superheater and an absorption tower, wherein the left side of the synthesis tower is fixedly connected with an air inlet pipe, the right side of the synthesis tower is fixedly connected with a connecting sleeve, the back side of the connecting sleeve is fixedly connected with a flow sensor valve, the output end of the flow sensor valve is connected with the methane flash tank through a conduit, the methane flash tank is connected with the absorption tower through a conduit, the absorption tower is connected with the steam superheater through a conduit, a de-alcoholization distillation device is arranged on the back side of the methane flash tank, the absorption tower is connected with the de-alcoholization distillation device through a conduit, and the upper surface of the steam superheater is fixedly connected with a fuel gas pipeline network.

[0009] In a further embodiment, a warning sign is fixedly connected to the front side of the synthesis tower.

[0010] In a further embodiment, a base is fixedly connected to the bottom surface of the methane flash tank, two mounting blocks are fixedly connected to the front and back of the base, and a mounting hole is formed on the upper surface of each mounting block.

[0011] In a further embodiment, a potential plate is fixedly connected to the front side of the steam superheater, and a group of status display lights is fixedly connected to the front side of the potential plate.

[0012] In a further embodiment, a parameter plate is provided on the left side of the steam superheater, and the right side of the parameter plate is fixedly connected to the left side of the steam superheater.

[0013] In a further embodiment, the bottom surface of the synthesis tower is fixedly connected to a base, and the bottom surface of the synthesis tower is fixedly connected to a fixing plate.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The device continuously supplies raw gas to the synthesis tower through the air inlet pipe, and then the crude methanol coming out of the synthesis tower first enters the methane flash tank, and the methane flash tank is used to flash the crude methanol under a reduced pressure environment to separate the flash gas, and the flash gas enters the absorption tower for desalted water washing treatment. The treated non-condensable steam is used as fuel for the steam superheater to make the non-condensable steam fully burn, and finally it is sent to the fuel gas pipeline network after being burned in the steam superheater, realizing the recovery and reuse of energy, improving the utilization efficiency of energy and reducing energy consumption. At the same time, the desalted water washing treatment of the absorption tower can more effectively separate and recover the useful components in the crude methanol, thereby The overall recovery efficiency of methanol is improved, and the crude methanol received from the methane flash tank and the bottom of the absorption tower by the de-alcoholization distillation device can be further purified and separated to remove impurities and other components, so as to obtain a higher purity methanol product. The problem of the steam superheater being tripped due to the increase in the amount of non-condensable steam in the methanol flash tank carrying part of the water vapor in the relaxation gas water washing tower, is effectively solved, avoiding the adverse effects of abnormal fluctuations of the steam superheater on the temperature of the 4.0 steam network and the normal operation of the synthesis gas turbine and the carbon dioxide turbine, eliminating the great hidden dangers to the normal and stable production operation of the steam system and the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the three-dimensional structure of the methanol synthesis flash gas recovery and utilization system.

[0017] Figure 2 This is a schematic diagram of the three-dimensional structure from a rear perspective of a methanol synthesis flash gas recovery system.

[0018] Figure 3 This is a schematic diagram of the three-dimensional structure from top and rear perspectives of the methanol synthesis flash gas recovery system.

[0019] Figure 4 This is a schematic diagram of the system structure in the methanol synthesis flash gas recovery and utilization system.

[0020] In the figure: 1. synthesis tower; 2. methane flash tank; 3. steam superheater; 4. air inlet pipe; 5. warning sign; 6. potential board; 7. status display light; 8. parameter board; 9. mounting block; 10. connecting sleeve; 11. absorption tower; 12. fuel gas pipeline network; 13. fixing plate; 14. base; 15. base; 16. flow sensor valve; 17. de-alcohol distillation device. DETAILED DESCRIPTION

[0021] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0023] 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.

[0024] See also Figure 1-4In the utility model, a methanol synthesis flash gas recovery and utilization system comprises a synthesis tower 1, a methane flash tank 2, a steam superheater 3 and an absorption tower 11. The left side of the synthesis tower 1 is fixedly connected with an air inlet pipe 4, the right side of the synthesis tower 1 is fixedly connected with a connecting sleeve 10, the back of the connecting sleeve 10 is fixedly connected with a flow sensor valve 16, the output end of the flow sensor valve 16 is connected with the methane flash tank 2 through a conduit, the methane flash tank 2 is connected with the absorption tower 11 through a conduit, the absorption tower 11 is connected with the steam superheater 3 through a conduit, a de-alcoholization distillation device 17 is arranged on the back of the methane flash tank 2, the absorption tower 11 is connected with the de-alcoholization distillation device 17 through a conduit, and the upper surface of the steam superheater 3 is fixedly connected with a fuel The gas pipe network 12 continuously supplies raw gas to the synthesis tower 1 through the air inlet pipe 4, and then the crude methanol coming out of the synthesis tower 1 first enters the methane flash tank 2, and the methane flash tank 2 is used to flash the crude methanol under a reduced pressure environment to separate the flash gas, and the flash gas enters the absorption tower 11 for desalted water washing treatment. The treated non-condensable steam is used as fuel for the steam superheater 3, so that the non-condensable steam is fully burned, and the heat and products generated by the combustion are transported to the fuel gas pipe network 12, and finally the alcohol removal distillation device 17 is used to receive the crude methanol from the methane flash tank 2 and the bottom of the absorption tower 11. Through the distillation process, the crude methanol can be further purified and separated to remove impurities and other components therein, so as to obtain a methanol product with a higher purity.

[0025] A warning sign 5 is fixedly connected to the front of the synthesis tower 1. The warning sign 5 can warn irrelevant personnel to avoid accidental touch. A base 14 is fixedly connected to the bottom surface of the methane flash tank 2. Two mounting blocks 9 are fixedly connected to the front and back of the base 14. Each mounting block 9 has a mounting hole on its upper surface. The mounting blocks 9 can facilitate the installation of the methane flash tank 2 by the staff. A potential plate 6 is fixedly connected to the front of the steam superheater 3. A group of status display lights 7 are fixedly connected to the front of the potential plate 6. The status display lights 7 can facilitate the staff to understand the operating status of the equipment.

[0026] A parameter sign 8 is provided on the left side of the steam superheating furnace 3, and the right side of the parameter sign 8 is fixedly connected to the left side of the steam superheating furnace 3. The parameter sign 8 can facilitate the staff to understand the basic parameters of the device. The bottom surface of the synthesis tower 1 is fixedly connected to a base 15, and the bottom surface of the synthesis tower 1 is fixedly connected to a fixed plate 13. The base 15 and the fixed plate 13 can improve the stability of the equipment.

[0027] The working principle of the utility model is:

[0028] When in use, raw gas is continuously supplied to the synthesis tower 1 through the air inlet pipe 4, and then the crude methanol coming out of the synthesis tower 1 first enters the methane flash tank 2, and the methane flash tank 2 is used to flash the crude methanol under a reduced pressure environment to separate the flash gas, and the flash gas then enters the absorption tower 11 for desalted water washing treatment, and the treated non-condensable steam is used as fuel for the steam superheater 3, so that the non-condensable steam is fully burned, and the heat and products generated by the combustion are transported to the fuel gas pipeline 12, and finally the alcohol removal distillation device 17 is used to receive the crude methanol from the methane flash tank 2 and the bottom of the absorption tower 11, and high-purity methanol and other products are separated and purified through the distillation process.

[0029] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0030] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A methanol synthesis flash gas recovery and utilization system, characterized in that: The invention comprises a synthesis tower (1), a methane flash tank (2), a steam superheater (3) and an absorption tower (11), wherein the left side of the synthesis tower (1) is fixedly connected to an air inlet pipe (4), the right side of the synthesis tower (1) is fixedly connected to a connecting sleeve (10), the back side of the connecting sleeve (10) is fixedly connected to a flow sensor valve (16), the output end of the flow sensor valve (16) is connected to the methane flash tank (2) through a conduit, the methane flash tank (2) is connected to the absorption tower (11) through a conduit, the absorption tower (11) is connected to the steam superheater (3) through a conduit, a de-alcohol distillation device (17) is provided on the back side of the methane flash tank (2), the absorption tower (11) is connected to the de-alcohol distillation device (17) through a conduit, and the upper surface of the steam superheater (3) is fixedly connected to a fuel gas pipeline network (12).

2. A methanol synthesis flash gas recovery and utilization system according to claim 1, characterized in that: A warning sign (5) is fixedly connected to the front of the synthesis tower (1).

3. The methanol synthesis flash gas recovery and utilization system according to claim 1, characterized in that: The bottom surface of the methane flash tank (2) is fixedly connected to a base (14), the front side of the base (14) and the back side of the base (14) are both fixedly connected to two mounting blocks (9), and the upper surface of each mounting block (9) is provided with a mounting hole.

4. The methanol synthesis flash gas recovery and utilization system according to claim 1, characterized in that: A potential plate (6) is fixedly connected to the front of the steam superheating furnace (3), and a group of status display lights (7) is fixedly connected to the front of the potential plate (6).

5. The methanol synthesis flash gas recovery and utilization system according to claim 1, characterized in that: A parameter plate (8) is provided on the left side of the steam superheating furnace (3), and the right side of the parameter plate (8) is fixedly connected to the left side of the steam superheating furnace (3).

6. The methanol synthesis flash gas recovery and utilization system according to claim 1, characterized in that: The bottom surface of the synthesis tower (1) is fixedly connected to a base (15), and the bottom surface of the synthesis tower (1) is fixedly connected to a fixing plate (13).

Images