Methane hydrogen regeneration olefin recovery system

Abstract

The system is characterized in that the input end of a methane hydrogen heater is communicated with a demethanizer, and the output end of the methane hydrogen heater is communicated with the input end of a liquid phase dryer; the output end of the mixed C4 heater is communicated between the output end of the methane hydrogen heater and the input end of the liquid phase dryer; the output end of the gas-liquid separation tank is communicated with the input end of the regenerated methane hydrogen coalescer; and the output end of the regenerated methane hydrogen coalescer is communicated with the input end of an external fuel pipe network. According to the utility model, a mixed C4 steam stripping process and a regenerated methane hydrogen secondary dehydration process are added, so that the water content in regenerated methane hydrogen gas is ensured to meet the requirements of receiving conditions of a fuel gas pipe network. According to the system for regenerating and recycling olefin by using methane hydrogen, disclosed by the invention, a mixed C4 and methane hydrogen medium is self-produced, so that the purpose of regenerating and recycling ethylene-propylene olefin substances by using the liquid-phase dryer is achieved, the nitrogen consumption and the torch gas emission are reduced, and the ethylene-propylene yield and the resource utilization rate are improved.

Description

Technical Field

[0001] The present application relates to the technical field of chemical tail gas recovery, and in particular to a methane hydrogen regeneration and olefin recovery system. Background Art

[0002] Olefins can be found everywhere in our daily lives, such as plastic bags, meltblown fabrics for masks, special clothing fabrics, etc. The mainstream method of producing olefins internationally is to use petroleum as raw material. However, the current environment is often rich in coal, poor in oil and has little gas. If coal can be used instead of petroleum to produce olefins, it will be of great significance to alleviate the tense situation of petroleum supply and ensure my country's energy security.

[0003] The olefin separation units of methanol-to-olefins complexes currently in operation are equipped with vapor-phase dryers, liquid-phase dryers, and propylene product guard beds to dry the material. Once the bed is saturated with water, it undergoes regeneration using nitrogen (N2). The regeneration process includes: liquid pouring → pressure relief → N2 cold blow → N2 heating → N2 constant temperature → N2 cooling → gaseous hydrocarbon replacement of N2 → liquid pouring → liquid filling → parallel operation. During this regeneration process, the remaining hydrocarbons (ethylene, propylene, and others) adsorbed on the desiccant bed must be discharged into the flare system during the "N2 cold blow," "N2 heating," "N2 constant temperature," "N2 cooling," and "gaseous hydrocarbon replacement of N2" stages. This results in material waste and low olefin recovery rates. Utility Model Content

[0004] The embodiments of the present application provide a methane hydrogen regeneration olefin recovery system, aiming to save materials while improving the olefin recovery efficiency.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] A methane hydrogen regeneration and olefin recovery system comprises a mixed C4 heater, a methane hydrogen heater, a liquid phase dryer, a gas-liquid separation tank and a regenerated methane hydrogen coalescer;

[0007] The input end of the methane hydrogen heater is communicated with the output end of the demethanizer;

[0008] The input end of the mixed C4 heater is connected to the output end of the external mixed C4 supply system;

[0009] The output end of the methane hydrogen heater and the output end of the mixed C4 heater are both connected to the input end of the liquid phase dryer;

[0010] The output end of the liquid phase dryer is respectively connected to the input end of the stripping gas pipeline and the input end of the gas-liquid separation tank;

[0011] The output end of the gas-liquid separation tank is communicated with the input end of the regenerated methane hydrogen coalescer;

[0012] The output end of the regenerated methane hydrogen coalescer is communicated with the input end of an external fuel pipe network.

[0013] Further, it also includes a regenerative methane hydrogen cooler;

[0014] The input end of the regenerated methane hydrogen cooler is communicated with the output end of the liquid phase dryer, and the output end thereof is communicated with the input end of the gas-liquid separation tank.

[0015] Further, an external reaction gas compressor is included;

[0016] The output end of the stripping gas pipeline is communicated with the input end of an external reaction gas compressor.

[0017] Furthermore, the output end of the mixed C4 heater is connected to a first valve, the output end of the methane hydrogen heater is connected to a second valve, the input end of the stripping gas pipeline is connected to a third valve, and the input end of the regenerated methane hydrogen cooler is connected to a fourth valve.

[0018] Furthermore, the regenerated methane hydrogen agglomerator is a vertical structure, and a plurality of filter plates are evenly and vertically arranged inside the regenerated methane hydrogen agglomerator. The cross-sectional profile of the filter plates in horizontal projection is a sine-cosine structure.

[0019] Furthermore, a plurality of filter holes are provided on the plate surface of the filter plate, and the pore diameters of the filter holes increase gradually from the inside of the regenerated methane hydrogen agglomerator to the outside.

[0020] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects:

[0021] The external mixed C4 supply system of the present application transports the mixed C4 to the mixed C4 heater, and the heated mixed C4 is sent to the liquid phase dryer through a pipeline. The methane hydrogen gas at the output end of the demethanizer enters the methane hydrogen heater and is also sent to the liquid phase dryer after being heated. The fluids of the methane hydrogen heater and the mixed C4 heater flow into the interior of the liquid phase dryer and react with the desiccant bed inside the dryer to purify the residual ethylene propylene olefins in the bed to achieve recovery. The gas-liquid separator separates the gas and liquid, and the liquid is sent to the regenerated methane hydrogen condenser through a pipeline. The regenerated methane hydrogen condenser processes and recovers the methane hydrogen gas and outputs it to the external fuel pipeline network for reuse.

[0022] The methane hydrogen is first heated in a methane hydrogen heater. The heated methane hydrogen is then transferred to a liquid-phase dryer, where it reacts with the desiccant bed within the dryer to complete regeneration. The regenerated methane hydrogen is then transferred to a gas-liquid separator for dehydration. After gas-liquid separation, the regenerated methane hydrogen enters a regenerated methane hydrogen coalescer for secondary dehydration. When the water content is reduced to within the target range, the regenerated methane hydrogen is transferred to the external fuel network. This double dehydration process reduces material usage and lowers the water content of the regenerated methane hydrogen gas, thereby improving the recovery rate of ethylene and / or propylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of the structure provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the internal structure of the regenerated methane hydrogen coalescer provided in an embodiment of the present application;

[0026] Figure 3 Schematic diagram of the structure of the filter plate in this application.

[0027] Icons: 1-demethanizer; 2-external mixed C4 supply system; 3-external reaction gas compressor; 4-external fuel pipeline; 10-mixed C4 heater; 20-methane hydrogen heater; 30-liquid phase dryer; 40-methane hydrogen cooler; 50-gas-liquid separation tank; 60-regenerated methane hydrogen coalescer; 61-filter plate; 62-filter hole; A-first valve; B-second valve; C-third valve; D-fourth valve; 70-stripping gas pipeline; DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected" and "connected" 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 an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0030] like Figure 1-Figure 3 As shown, a methane hydrogen regeneration and olefin recovery system includes a mixed C4 heater 10, a methane hydrogen heater 20, a liquid phase dryer 30, a gas-liquid separation tank 50 and a regenerated methane hydrogen agglomerator 60; the input end of the methane hydrogen heater 20 is connected to the output end of the demethanizer 1; the input end of the mixed C4 heater 10 is connected to the output end of the external mixed C4 supply system 2; the output end of the methane hydrogen heater 20 and the output end of the mixed C4 heater 10 are both connected to the input end of the liquid phase dryer 30; the output end of the liquid phase dryer 30 is respectively connected to the input end of the stripping gas pipeline 70 and the input end of the gas-liquid separation tank 50; the output end of the gas-liquid separation tank 50 is connected to the input end of the regenerated methane hydrogen agglomerator 60; the output end of the regenerated methane hydrogen agglomerator 60 is connected to the input end of the external fuel pipeline 4.

[0031] The methane hydrogen regeneration and olefin recovery system in this application includes a mixed C4 heater 10, a methane hydrogen heater 20, a liquid phase dryer 30, a gas-liquid separation tank 40 and a regenerated methane hydrogen condenser 60, which is mainly used in the olefin separation operation scenario of methanol to olefins.

[0032] Among them, the external mixed C4 supply system of the present application transports the mixed C4 to the mixed C4 heater 10, and the heated mixed C4 is sent to the liquid phase dryer 30 through a pipeline. The methane hydrogen gas at the output end of the demethanizer 1 enters the methane hydrogen heater 20, and is also sent to the liquid phase dryer 30 after being heated. In this process, the heated methane hydrogen and mixed C4 can enter the liquid phase dryer 30 at the same time, or they can be distributed into the liquid phase dryer 30 through an external control system. The fluids of the methane hydrogen heater 20 and the mixed C4 heater 10 enter the interior of the liquid phase dryer 30 and react with the internal desiccant bed, and then the treated gas is sent to the stripping gas pipeline 70 and the gas-liquid separation tank 50. The gas-liquid separation tank 50 separates the gas and liquid, and the liquid is sent to the regenerated methane hydrogen condenser 60 through a pipeline. The regenerated methane hydrogen condenser 60 processes and recovers the methane hydrogen gas and outputs it to the external fuel pipeline 4 for reuse.

[0033] The methane hydrogen is first heated in a methane hydrogen heater 20. The heated methane hydrogen is then transferred to a liquid-phase dryer 30, where it reacts with the desiccant within the dryer to regenerate the methane hydrogen. The regenerated methane hydrogen is then transferred to a gas-liquid separator 40 for dehydration. After gas-liquid separation, the regenerated methane hydrogen enters a regenerated methane hydrogen coalescer 60 for secondary dehydration. When the water content is reduced to within the target range, the regenerated methane hydrogen is transferred to the external fuel pipeline 4. This double dehydration process reduces material usage and lowers the water content of the regenerated methane hydrogen gas, thereby improving the recovery rate of ethylene and / or propylene.

[0034] The present application further includes a regenerated methane hydrogen cooler 40 ; the input end of the regenerated methane hydrogen cooler 40 is connected to the output end of the liquid phase dryer 30 , and the output end thereof is connected to the input end of the gas-liquid separation tank 50 .

[0035] After the regenerated methane hydrogen mixed components are cooled by the regenerated methane hydrogen cooler 50, gas-liquid separation is carried out in the gas-liquid separation tank 40, and preliminary liquid separation is performed to preliminarily separate some low-carbon olefin components, water, ethylene and propylene, thereby reducing the working pressure for subsequent secondary dehydration while improving the efficiency of ethylene and / or propylene.

[0036] The present application further includes an external reaction gas compressor 3 ; the output end of the stripping gas pipeline 70 is communicated with the input end of the external reaction gas compressor 3 .

[0037] The stripping gas pipeline 70 is provided to collect the gaseous mixed C4 after stripping through the desiccant bed inside the liquid phase dryer 30, and to transport the gaseous mixed C4 to the input end of the external reaction gas compressor 3 for centralized recovery and treatment.

[0038] The output end of the mixed C4 heater 10 is connected to a first valve A, the output end of the methane hydrogen heater 20 is connected to a second valve B, the input end of the stripping gas pipeline 70 is connected to a third valve C, and the input end of the regenerated methane hydrogen cooler 40 is connected to a fourth valve D.

[0039] The regeneration process of the liquid-phase dryer 30 in this application is sequentially controlled by the first valve A, the second valve B, the third valve C, and the fourth valve D, ensuring that the liquid-phase dryer 30 regenerates methane hydrogen according to the steps of "liquid pouring → pressure relief → mixed C4 stripping → methane hydrogen cold blowing → methane hydrogen heating → methane hydrogen constant temperature → methane hydrogen cooling → liquid pouring → liquid filling → parallel operation." The first valve A, the second valve B, the third valve C, and the fourth valve D in this application are electrically connected to an external control system, allowing staff to control the start and stop of the methane hydrogen regeneration process of the liquid-phase dryer 30 in real time to reduce the water content and light olefin components of the regenerated methane hydrogen.

[0040] The regenerated methane hydrogen coalescer 60 is a vertical structure, and a plurality of filter plates 61 are evenly and vertically arranged inside the regenerated methane hydrogen coalescer 60 . The cross-sectional profile of the filter plates 61 in horizontal projection is a sine-cosine structure.

[0041] The regenerated methane hydrogen coalescer 60 in this application is configured as a vertical structure. This design is intended to account for the gravity difference between gaseous methane hydrogen and water droplets, allowing the gaseous methane hydrogen to move freely and irregularly upward, while the water droplets move freely and downward. The filter plate 61 constrains the path of the water droplets. The sine-cosine structure of the filter plate 61 fully utilizes the limited space within the regenerated methane hydrogen coalescer 60 and reduces the resistance of the filter plate 61 to the regenerated methane hydrogen.

[0042] A plurality of filter holes 62 are formed on the surface of the filter plate 61 , and the radial directions of the filter holes 62 increase from the inside of the regenerated methane hydrogen coalescer 60 to the outside.

[0043] In the above scheme, the pore size of the filter 62 is set to increase from the inside to the outside, which can condense the small droplets of regenerated methane hydrogen gas on the filter plate 61 into large droplets, accelerate the sedimentation of the liquid, and separate it from the gas-phase regenerated methane hydrogen, thereby increasing the ethylene and / or propylene content of the regenerated methane hydrogen.

[0044] The liquid phase dryer 30 can operate for a drying cycle of 72 hours, with a mixed C4 stripping time of 16 hours, a methane hydrogen heating / maintaining temperature time of 28 hours, and a methane hydrogen cooling time of 11 hours. The methane hydrogen heater 20 heats the methane hydrogen to 250°C before transferring it to the liquid phase dryer 30 and utilizing the desiccant therein for methane hydrogen regeneration. The regenerated methane hydrogen is then cooled to 40°C in the regenerated methane hydrogen cooler 50 and transferred to the gas-liquid separator 40. The regenerated methane hydrogen then enters the regenerated methane hydrogen coalescer 60 for secondary dehydration, reducing the water content in the regenerated methane hydrogen to less than 10 ppm before being incorporated into the fuel gas system.

[0045] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0046] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A methane hydrogen regeneration and olefin recovery system, characterized in that: It comprises a mixed C4 heater (10), a methane hydrogen heater (20), a liquid phase dryer (30), a gas-liquid separation tank (50) and a regenerated methane hydrogen coalescer (60); The input end of the methane hydrogen heater (20) is in communication with the output end of the demethanizer (1); The input end of the mixed C4 heater (10) is in communication with the output end of the external mixed C4 supply system (2); The output end of the methane hydrogen heater (20) and the output end of the mixed C4 heater (10) are both connected to the input end of the liquid phase dryer (30); The output end of the liquid phase dryer (30) is connected to the input end of the stripping gas pipeline (70) and the input end of the gas-liquid separation tank (50) respectively; The output end of the gas-liquid separation tank (50) is in communication with the input end of the regenerated methane hydrogen coalescer (60); The output end of the regenerated methane hydrogen coalescer (60) is in communication with the input end of the external fuel pipe network (4).

2. The methane hydrogen regeneration and olefin recovery system according to claim 1, characterized in that: Also included is a regenerative methane hydrogen cooler (40); The input end of the regenerated methane hydrogen cooler (40) is communicated with the output end of the liquid phase dryer (30), and the output end thereof is communicated with the input end of the gas-liquid separation tank (50).

3. The methane hydrogen regeneration and olefin recovery system according to claim 2, characterized in that: Also included is an external reaction gas compressor (3); The output end of the stripping gas pipeline (70) is communicated with the input end of the external reaction gas compressor (3).

4. The methane hydrogen regeneration and olefin recovery system according to claim 3, characterized in that: The output end of the mixed C4 heater (10) is connected to a first valve (A), the output end of the methane hydrogen heater (20) is connected to a second valve (B), the input end of the stripping gas pipeline (70) is connected to a third valve (C), and the input end of the regenerated methane hydrogen cooler (40) is connected to a fourth valve (D).

5. The methane hydrogen regeneration and olefin recovery system according to claim 1, characterized in that: The regenerated methane hydrogen coalescer (60) is a vertical structure, and a plurality of filter plates (61) are radially arranged inside the structure; The cross-sectional profile of the filter plate (61) in horizontal projection is a sine-cosine structure.

6. The methane hydrogen regeneration and olefin recovery system according to claim 5, characterized in that: A plurality of filter holes (62) are provided on the plate surface of the filter plate (61), and the pore diameters of the filter holes (62) increase sequentially from the inside of the regenerated methane hydrogen agglomerator (60) to the outside.

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