Amine liquid purification system

Abstract

The utility model relates to an amine liquid purification system and belongs to the technical field of amine liquid purification. Comprising a purifier which is provided with a bottom plate; the bottom plate is provided with a liquid inlet; a liquid outlet is formed in the top of the purifier; a filler is arranged in the purifier; a plurality of grooves are formed in the side, located in the purifier, of the bottom plate and extend towards the boundary of the bottom plate with the liquid inlet as the center. The liquid inlet is connected with the filter II; the liquid outlet is connected with the lean amine tank; the filter II is connected with the production system; the production system is connected with the filter I; the filter I is connected with the heat exchanger II; the heat exchanger II is connected with the flash tank; the flash tank is connected with a low-temperature medium inlet of the heat exchanger I through a pump; a low-temperature medium outlet of the heat exchanger I is connected with the regeneration tower. After the purification system disclosed by the utility model runs for three months, the content of thermally stable salt in barren liquor is reduced from 1.8% to 1.15%, totally 3.25 tons of thermally stable salt is removed, and the system runs stably.

Description

Technical Field

[0001] The utility model relates to the technical field of amine liquid purification, in particular to an amine liquid purification system. Background Art

[0002] Amines are a general term for a class of organic alkaline solutions, typically referring to weakly alkaline organic amine solvents used to absorb hydrogen sulfide or carbon dioxide during desulfurization and decarbonization processes. Alcoholamines are the most common. Common examples include monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA), or mixtures thereof. Amines are commonly used in petroleum processing plants to desulfurize sour dry gas, liquefied petroleum gas, recycled hydrogen, and sulfur recovery unit off-gas. Amines absorb hydrogen sulfide from the gas to purify it. The amines are heated and stripped to release hydrogen sulfide, which is then recycled and sent to the sulfur recovery unit for sulfur production. With increasing sulfur content in processed crude oil, stricter product quality requirements, and stricter environmental regulations, amine desulfurization has become a crucial component of petroleum processing. The amine system has become the third largest logistics system after crude oil and circulating water systems. According to statistics, amine systems account for approximately 8% of a plant's total energy consumption, making them crucial for petrochemical operations.

[0003] In this context, it is particularly important to solve problems in the operation of the amine system. The content of heat-stable salts (HSS) in the amine solution gradually increases as production progresses. Heat-stable salts are a general term for a class of amine salts that do not decompose and regenerate at the operating temperature of the solvent desulfurization regeneration tower. They include sulfates, thiosulfates, nitrates, oxalates, formates, acetates, etc. High levels of heat-stable salts in the amine solution affect the quality of the amine solution. Because amine solution is prone to foaming, high levels of heat-stable salts can lead to tower overflow, severe equipment corrosion, large amine loss, reduced amine concentration, large amine circulation volume, and high energy consumption. Therefore, it is necessary to remove heat-stable salts from the amine solution in real time. Utility Model Content

[0004] Aiming at the problem of high content of heat-stable salt in existing amine solution, the utility model provides an amine solution purification system to solve the above problem.

[0005] A purification system for amine liquid comprises: a purifier, wherein the purifier is provided with a bottom plate; the bottom plate is provided with a liquid inlet; the top of the purifier is provided with a liquid outlet; the purifier contains a filler; a plurality of grooves are provided on one side of the bottom plate located inside the purifier, and the grooves extend toward the boundary of the bottom plate with the liquid inlet as the center; the liquid inlet is connected to a second filter; the liquid outlet is connected to a lean amine tank; the liquid inlet is connected to a second filter; the second filter is connected to a production system; the production system is also connected to a first filter; the first filter is connected to a low-temperature medium inlet of a second heat exchanger; the low-temperature medium outlet of the second heat exchanger is connected to a flash tank; the flash tank is connected to the low-temperature medium inlet of the first heat exchanger via a pump; the low-temperature medium outlet of the first heat exchanger is connected to a regeneration tower; the bottom outlet of the regeneration tower is connected to the heat medium inlet of the first heat exchanger; the heat medium outlet of the first heat exchanger is connected to the heat medium inlet of the second heat exchanger; and the heat medium outlet of the second heat exchanger is connected to the lean amine tank.

[0006] Furthermore, the filler is resin.

[0007] Furthermore, a reboiler is connected to the bottom of the regeneration tower. The amine liquid at the bottom of the regeneration tower enters the reboiler, where it is heated by 0.3MPa steam and condensate from the stripping condensate tank, providing a heat source for regenerating the rich amine liquid. The condensate produced by the reboiler enters the condensate tank, where the liquid level is controlled by a regulating valve and then sent to the condensate pipe network.

[0008] Furthermore, a cooler is installed between the heat medium outlet of heat exchanger 2 and the lean amine tank. After two heat exchanges, the purified lean amine liquid remains very hot. Long-term monitoring shows that the temperature of the lean amine liquid after heat exchange is generally around 73°C. At this point, the lean amine liquid entering the lean amine tank needs to be further cooled to ensure smooth operation. The cooled lean amine liquid is stored in the lean amine tank at a temperature of approximately 40°C, greatly improving the safety of the equipment.

[0009] Furthermore, the cooler adopts a water-cooling refrigeration method.

[0010] Furthermore, the lean amine tank is connected to Filter 2 and the production system. The production system includes a sulfur recovery unit, a stripping desulfurization tower, and other desulfurization equipment. Most of the lean amine liquid is pumped to a higher pressure and sent to the production system for further use. A small amount of lean amine liquid is passed through Filter 2 to remove impurities and then circulated.

[0011] Furthermore, the lean amine tank is a sealed device, and the pressure inside the tank is greater than atmospheric pressure. This airtight seal prevents air from entering the lean amine tank and causing oxidation, which can increase the thermally stable salt content of the amine liquid. Nitrogen sealing is also added to maintain positive pressure inside the tank, preventing the amine liquid from coming into contact with air.

[0012] The working principle of the present invention is as follows: the rich amine liquid generated from the production system 4 is filtered by filter 16 and then enters heat exchanger 2 10. After being heated by heat exchanger 2 10, it enters the flash tank 5. The high-concentration rich amine liquid from the flash tank is further heated by heat exchanger 19 and enters the regeneration tower 2. The rich amine liquid in the regeneration tower 2 removes hydrogen sulfide and becomes lean amine liquid. This liquid flows out from the bottom of the tower and passes through heat exchanger 19, providing a heat source to heat the rich amine liquid entering the regeneration tower 2 while also lowering its own temperature. It then passes through heat exchanger 2 10, providing a heat source to heat the rich amine liquid before entering the flash tank 5, further lowering its temperature. It finally enters the lean amine tank 1. The lean amine liquid entering the lean amine tank is then filtered by filter 2 and enters the purifier. Impurities in the lean amine liquid are adsorbed by the filler in the purifier, further increasing its purity. The lean amine liquid is then returned to the lean amine tank for storage.

[0013] The beneficial effects of the present invention are:

[0014] The amine liquid purification system provided by this utility model improves the removal efficiency of heat-stable salts. After obtaining lean amine liquid, it undergoes further purification in a purifier. Divergent grooves are provided at the purifier's feed inlet, ensuring that the incoming amine liquid is evenly distributed throughout the purifier, improving purification efficiency. Statistics show that after three months of operation, the heat-stable salt content in the lean liquid was reduced from 1.8% to 1.15%, removing a total of 3.25 tons of heat-stable salts. The system also operates stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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 or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0017] Figure 2 This is a schematic structural diagram of the purifier of the utility model.

[0018] Figure 3 This is a schematic structural diagram of the base plate of the purifier of the present invention.

[0019] In the figure, 1-lean amine tank, 2-regeneration tower, 3-purifier, 4-production system, 5-flash tank, 6-filter 1, 7-filter 2, 8-reboiler, 9-heat exchanger 1, 10-heat exchanger 2, 11-cooler, 12-filler, 13-bottom plate, 14-liquid inlet, 15-groove, 16-liquid outlet. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will be combined with the drawings of the embodiments of the present invention to clearly and completely describe the technical solutions of the embodiments of the present invention. Obviously, the embodiments described are only 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 should fall within the scope of protection of the present invention.

[0021] Example 1

[0022] A purification system for amine liquid includes: a purifier 3, the purifier 3 is provided with a bottom plate 13; the bottom plate 13 is provided with a liquid inlet 14; the top of the purifier 3 is provided with a liquid outlet 16; a filler 12 is provided in the purifier 3, and the filler 12 is a resin; a plurality of grooves 15 are provided on one side of the bottom plate 13 located inside the purifier 3, and the grooves 15 extend toward the boundary of the bottom plate 13 with the liquid inlet 14 as the center; the liquid inlet 14 is connected to the filter 2 7; the liquid outlet 16 is connected to the lean amine tank 1; the liquid inlet 14 is connected to the filter 2 7; the filter 2 7 is connected to the production system 4; the production system System 4 is also connected to filter 6; filter 6 is connected to the low-temperature medium inlet of heat exchanger 2 10; the low-temperature medium outlet of heat exchanger 2 10 is connected to the flash tank 5; the flash tank 5 is connected to the low-temperature medium inlet of heat exchanger 19 through a pump; the low-temperature medium outlet of heat exchanger 9 is connected to the regeneration tower 2; the reboiler 8 is connected to the bottom of the regeneration tower 2; the bottom outlet of the regeneration tower 2 is connected to the hot medium inlet of heat exchanger 19; the hot medium outlet of heat exchanger 9 is connected to the hot medium inlet of heat exchanger 2 10; the hot medium outlet of heat exchanger 2 10 is connected to the lean amine tank 1.

[0023] Example 2

[0024] A purification system for amine liquid, comprising: a purifier 3, the purifier 3 is provided with a bottom plate 13; the bottom plate 13 is provided with a liquid inlet 14; the top of the purifier 3 is provided with a liquid outlet 16; a filler 12 is provided in the purifier 3, and the filler 12 is a resin; the bottom plate 13 is located inside the purifier 3 and is provided with a plurality of grooves 15 on one side, and the grooves 15 extend toward the boundary of the bottom plate 13 with the liquid inlet 14 as the center; the liquid inlet 14 is connected to the filter 2 7; the liquid outlet 16 is connected to the lean amine tank 1; the lean amine tank 1 is a closed device, and the pressure in the tank is greater than the atmospheric pressure; the liquid inlet 14 is connected to the filter 2 7; the filter 2 7 is connected to the production system 4; the production system 4 is also connected to the filter 1 6; the filter 1 6 is connected to the heat exchanger The low-temperature medium inlet of heat exchanger 2 10 is connected; the low-temperature medium outlet of heat exchanger 2 10 is connected to the flash tank 5; the flash tank 5 is connected to the low-temperature medium inlet of heat exchanger 1 9 through a pump; the low-temperature medium outlet of heat exchanger 1 9 is connected to the regeneration tower 2; the reboiler 8 is connected to the bottom of the regeneration tower 2; the bottom outlet of the regeneration tower 2 is connected to the hot medium inlet of heat exchanger 1 9; the hot medium outlet of heat exchanger 1 9 is connected to the hot medium inlet of heat exchanger 2 10; the hot medium outlet of heat exchanger 2 10 is connected to the lean amine tank 1; a cooler 11 is provided between the hot medium outlet of heat exchanger 2 10 and the lean amine tank 1; the cooler 11 adopts a water-cooled refrigeration method; the lean amine tank 1 is also connected to the filter 2 7 and the production system 4 respectively.

[0025] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall fall within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A purification system for amine liquid, comprising a purifier, the purifier having a bottom plate; a liquid inlet on the bottom plate; a liquid outlet on the top of the purifier; a filler in the purifier; characterized in that: A bottom plate is located on one side of the interior of the purifier and is provided with a plurality of grooves, which extend toward the boundary of the bottom plate with the liquid inlet as the center; the liquid inlet is connected to filter 2; the liquid outlet is connected to the lean amine tank; filter 2 is connected to the production system; the production system is also connected to filter 1; filter 1 is connected to the low-temperature medium inlet of heat exchanger 2; the low-temperature medium outlet of heat exchanger 2 is connected to the flash tank; the flash tank is connected to the low-temperature medium inlet of heat exchanger 1 through a pump; the low-temperature medium outlet of heat exchanger 1 is connected to the regeneration tower; the bottom outlet of the regeneration tower is connected to the heat medium inlet of heat exchanger 1; the heat medium outlet of heat exchanger 1 is connected to the heat medium inlet of heat exchanger 2; and the heat medium outlet of heat exchanger 2 is connected to the lean amine tank.

2. The amine liquid purification system according to claim 1, characterized in that: The filling is resin.

3. The amine liquid purification system according to claim 1, characterized in that: A reboiler is connected to the bottom of the regeneration tower.

4. The amine liquid purification system according to claim 1, characterized in that: A cooler is provided between the hot medium outlet of the second heat exchanger and the lean amine tank.

5. The amine liquid purification system according to claim 1, characterized in that: The lean amine tank is also connected to filter 2 and the production system respectively.

6. The amine liquid purification system according to claim 1, characterized in that: The lean amine tank is a closed device, and the pressure inside the tank is greater than atmospheric pressure.

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