Treatment device and treatment method for conversion condensate
By using a combination system of deacidized ammonia absorbing tower and ammonia distillation tower in the conversion condensate treatment process, the problems of low ammonia water concentration and difficult to recover acid gas in the prior art are solved, effective separation of acid gas and sulfur recovery are achieved, ammonia water concentration is controlled, and the accumulation of ammonia and nitrogen gas is slowed down.
Patent Information
- Application Number
- CN202411818841.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-03-07
AI Technical Summary
The existing conversion condensate treatment process cannot effectively recover ammonia, resulting in low ammonia water concentration, resulting in large load on the equipment and no external sales value. At the same time, acidic gas is difficult to send to the sulfur recovery device, resulting in clogging of the pipeline and equipment.
The treatment device including a stripping system, a deacid gas system and an ammonia vaporization system is adopted to separate the acid gas by cooling and washing and separating the acid gas by two sections of the deacid ammonia aspiration tower, adjust the return flow rate of the ammonia vaporization tower to control the ammonia water concentration, and reasonably control the tower kettle temperature by adding an ammonia vaporization tower and a reboiler to slow down the accumulation of ammonia and nitrogen gas.
It realizes effective separation of acid gas and sulfur recovery, avoids crystallization blockage of equipment, controls ammonia water concentration, slows down the accumulation of ammonia and nitrogen gases, and improves process efficiency and product quality.
Smart Images
Figure CN119565202A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of synthetic ammonia conversion condensate treatment, and in particular to a treatment device and method for conversion condensate. Background Art
[0002] Currently, the shift process condensate is commonly processed using a single-tower, low-pressure stripping method. This stripping method primarily removes gases such as ammonia and nitrogen from the condensate to prevent their accumulation in the system when the condensate is returned to the gasification system for reuse. Purified water at the bottom of the tower, with reduced ammonia and nitrogen content, is returned to the gasification slag water unit. The overhead vapor phase is cooled and separated, and the ammonia-containing gas can be sent to the sulfur recovery unit. However, because ammonia-containing gas is prone to ammonium salt crystallization at low temperatures, clogging equipment and pipelines, in actual operation, the ammonia-containing gas from the shift stripping process is often flared. Because flash gas and low-temperature condensate contain acid gases such as CO2 and H2S, the dilute ammonia water at the top of the tower contains sulfur, resulting in poor quality. Furthermore, the low ammonia concentration results in heavy loads on the 8% ammonia water tank, making it essentially worthless for external sale. This process neither effectively recovers ammonia nor produces acid gas suitable for the sulfur recovery unit. Summary of the Invention
[0003] The present invention aims to provide a device and method for treating conversion condensate. After two-stage cooling and washing in a deacidification and ammonia absorption tower, the acid gas emerging from the top of the deacidification and ammonia absorption tower is essentially free of steam and ammonia. The acid gas can be sent to a sulfur recovery combustion recovery process, thereby avoiding crystallization blockage of pipelines and equipment. The amount of steam carried out from the top of the ammonia evaporation tower is adjusted by adjusting the reflux volume of the ammonia evaporation tower, thereby controlling the ammonia concentration without the need for an external water source. By adding an ammonia evaporation tower and a reboiler and rationally controlling the tower bottom temperature, the ammonia nitrogen content of the condensate from the ammonia evaporation tower can be lower than that of the condensate from the stripping tower, further mitigating the accumulation of ammonia, nitrogen, and other gases in the system caused by the condensate being returned to the vaporization and reuse process.
[0004] To achieve the above objectives, the present invention provides a treatment device for conversion condensate, comprising a stripping system, a deacidification system and an ammonia distillation system, wherein the stripping system is connected to the deacidification system via a pipeline, and the deacidification system is connected to the ammonia distillation system.
[0005] Preferably, the stripping system comprises a stripping tower, which is connected to a stripping tower kettle heat exchanger.
[0006] Preferably, the deacidification gas system includes a deacidification ammonia absorption tower, which is connected to the deacidification ammonia absorption tower kettle pump through a pipeline, and the deacidification ammonia absorption tower kettle pump is respectively connected to the water cooler and the first heat exchanger through pipelines, and the water cooler is connected to the deacidification ammonia absorption tower through a pipeline.
[0007] Preferably, the ammonia evaporation system includes an ammonia evaporation tower, which is connected to the first heat exchanger through a pipeline, the first heat exchanger is connected to the ammonia reflux tower through a pipeline, the ammonia reflux tower is connected to the ammonia pump and the deacidification and ammonia absorption tower through pipelines, and the kettle of the ammonia evaporation tower is provided with a reboiler.
[0008] Preferably, the stripping tower kettle heat exchanger and the ammonia still are both connected to the slag water system through pipelines.
[0009] Preferably, the deacidification and ammonia absorption tower is connected to the sulfur recovery device.
[0010] Preferably, the upper part of the ammonia reflux tower is composed of a condensation section and a reflux section.
[0011] Preferably, a condensate cooler is installed on the pipeline connecting the ammonia still tower and the deacidification and ammonia absorption tower.
[0012] The present invention also provides a method for treating a conversion condensate, using the above-mentioned conversion condensate treatment device, comprising the following steps: Step 1: Stripping: During normal production, the stripping tower uses only vaporized low-flash gas. When the tower bottom temperature is difficult to raise, low-pressure steam is used to heat and strip the conversion condensate in the stripping tower to remove most of the ammonia and acid gases in the condensate. The purified process condensate at the bottom of the stripping tower is sent to the slag water system to separate the condensate from ammonia and acid gases. Step 2, ammonia absorption and deacidification: After the gas phase at the top of the stripping tower enters the deacidification and ammonia absorption tower, it is cooled and washed in the upper and lower sections of the deacidification and ammonia absorption tower. The steam and amino groups are condensed and absorbed. The acid gas coming out of the top of the deacidification and ammonia absorption tower basically does not contain steam and ammonia, thus achieving the separation of acid gas from ammonia and steam; Step 3, ammonia distillation: The dilute ammonia water with low concentration at the bottom of the deacidification and ammonia absorption tower is fed into the ammonia distillation tower. The bottom reboiler is used to heat the deacidification and ammonia absorption tower to a temperature slightly lower than the saturation temperature of the ammonia distillation tower pressure. At this time, the ammonia content in the tower bottom is already very low. The top temperature of the ammonia distillation tower is controlled by reflux, and the ratio of ammonia gas and steam at the top of the tower is controlled to achieve the conversion of ammonia water into ammonia gas and steam. Step 4, ammonia production: when the ammonia concentration at the bottom of the ammonia reflux tower is high, the reflux at the top of the ammonia evaporation tower is reduced to increase the steam carried out of the ammonia evaporation tower, and the ammonia concentration is reduced after cooling in the ammonia reflux tower; when the ammonia concentration at the bottom of the ammonia reflux tower is low, the reflux at the top of the ammonia evaporation tower is increased to reduce the steam carried out of the ammonia evaporation tower, and the ammonia concentration is increased after cooling in the ammonia reflux tower.
[0013] Therefore, the present invention adopts the above-mentioned device and method for processing the conversion condensate, which has the following beneficial effects: (1) The conversion condensate treatment device and treatment method of the present invention, after two-stage cooling and washing in the deacidification and ammonia absorption tower, the acid gas exiting the top of the deacidification and ammonia absorption tower is essentially free of steam and ammonia. The acid gas can be sent to sulfur recovery combustion for recovery treatment, and crystallization blockage of pipelines and equipment is also avoided.
[0014] (2) The conversion condensate treatment device and treatment method of the present invention adjusts the amount of steam carried out from the top of the ammonia evaporation tower by adjusting the reflux rate of the ammonia evaporation tower, thereby controlling the ammonia concentration without adding other water sources.
[0015] (3) The device and method for treating the conversion condensate of the present invention, by adding an ammonia still and a reboiler and rationally controlling the temperature of the tower bottom, can make the ammonia nitrogen content of the condensate of the ammonia still lower than that of the condensate of the stripping tower, thereby further alleviating the accumulation of ammonia, nitrogen and other gases in the system caused by the condensate being returned to the gasification for reuse.
[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 The present invention is a flowchart of an embodiment of a device and method for processing a conversion condensate.
[0018] Reference numerals 1. Stripping tower kettle heat exchanger; 2. Stripping tower; 3. Condensate cooler; 4. Deacidification and ammonia absorption tower; 5. Water cooler; 6. Deacidification and ammonia absorption tower kettle pump; 7. Ammonia reflux tower; 8. Ammonia pump; 9. First heat exchanger; 10. Ammonia distillation tower; 11. Reboiler. DETAILED DESCRIPTION
[0019] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.
[0020] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0021] Example 1 like Figure 1 As shown, the present invention provides a processing device for conversion condensate, including a stripping system, a deacidification system and an ammonia distillation system. The stripping system is connected to the deacidification system through a pipeline, and the deacidification system is connected to the ammonia distillation system.
[0022] The stripping system includes a stripping tower 2, which is connected to the stripping tower kettle heat exchanger 1. The low-temperature shift condensate at about 98°C first passes through the stripping tower kettle heat exchanger 1, exchanges heat with the kettle liquid at about 127°C, and then enters the upper part of the stripping tower 2 to increase the temperature. The vaporized low flash gas or low-pressure steam enters the tower from the bottom of the stripping tower 2, and transfers mass and heat with the shift condensate in countercurrent. Most of the ammonia and acid gas in the shift condensate are discharged from the top of the stripping tower 2 along with the steam. The purified stripping tower 2 kettle liquid is cooled to about 112°C by the stripping tower kettle heat exchanger 1 and then sent to the slag water system.
[0023] The acid gas removal system includes a deacidification and ammonia absorption tower 4, which is connected to a sulfur recovery unit. This tower is connected to a kettle pump 6 via a pipeline. The kettle pump 6 is connected to a water cooler 5 and a first heat exchanger 9 via pipelines, respectively. The water cooler 5 is also connected to the deacidification and ammonia absorption tower 4 via a pipeline.
[0024] The outlet gas of the stripping tower 2 at about 121°C is sent to the bottom of the deacidification and ammonia absorption tower 4. The deacidification and ammonia absorption tower 4 is divided into two sections, the upper and lower sections. The kettle pump 6 of the deacidification and ammonia absorption tower sends part of the kettle liquid to the water cooler 5 for cooling and then sends it back to the middle of the deacidification and ammonia absorption tower 4. The low-temperature kettle liquid at about 50°C transfers mass and heat with the acid gas at about 121°C in the packing layer of the lower section of the deacidification and ammonia absorption tower 4. Most of the ammonia and steam are condensed. The acid gas that continues to rise is washed and cooled by the low-temperature condensate at about 40°C in the upper section of the deacidification and ammonia absorption tower 4. The acid gas coming out of the top of the deacidification and ammonia absorption tower 4 is sent to the sulfur recovery device.
[0025] The ammonia distillation system includes an ammonia distillation column 10. The stripping column kettle heat exchanger 1 and the ammonia distillation column 10 are both connected to the slag water system via pipelines. A condensate cooler 3 is installed on the pipeline connecting the ammonia distillation column 10 to the deacidification and ammonia absorption column 4. The ammonia distillation column 10 is also connected to the first heat exchanger 9 via pipelines, which in turn is connected to the ammonia reflux column 7 via pipelines. The upper portion of the ammonia reflux column 7 is divided into a condensing section and a reflux section. The ammonia reflux column 7 is also connected to the ammonia pump 8 and the deacidification and ammonia absorption column 4 via pipelines. The kettle of the ammonia distillation column 10 is equipped with a reboiler 11.
[0026] The deacidification and ammonia absorption tower kettle pump 6 raises the temperature of another part of the kettle liquid through the first heat exchanger 9 and sends it to the upper part of the ammonia still 10. The kettle of the ammonia still 10 is provided with a reboiler 11. The low-ammonia nitrogen kettle liquid of the ammonia still 10 is sent to the slag water section together with the kettle liquid of the stripping tower 2. The higher temperature ammonia and steam move upward from the bottom of the ammonia still 10, heat the ammonia-containing condensate flowing down from the upper part in the packing layer, and separate the ammonia from the condensate. After the ammonia and steam are sent out from the top of the ammonia still 10, they are cooled by the first heat exchanger 9 and sent to the ammonia reflux tower 7. The upper part of the ammonia reflux tower 7 is divided into a condensation section and a reflux section. The gas phase from the top of the ammonia reflux tower 7 is sent to the bottom of the deacidification and ammonia absorption tower 4. The ammonia at the bottom of the ammonia reflux tower 7 is pumped back to the upper part of the reflux section of the ammonia reflux tower 7 by the ammonia pump 8 for circulation. An ammonia concentration meter is installed on the ammonia delivery pipeline to monitor the concentration of ammonia.
[0027] Example 2 The present invention also provides a method for treating a conversion condensate, using the above-mentioned conversion condensate treatment device, comprising the following steps: Step 1, stripping: During normal production, the stripping tower 2 is entirely filled with vaporized low-flash gas. When the temperature of the tower bottom is difficult to raise, low-pressure steam is used to heat and strip the conversion condensate in the stripping tower 2 to remove most of the ammonia and acid gases in the condensate. The purified process condensate at the bottom of the stripping tower 2 is sent to the slag water system to separate the condensate from ammonia and acid gases. Step 2, ammonia absorption and deacidification: After the top gas phase of the stripping tower 2 enters the deacidification and ammonia absorption tower 4, it is cooled and washed in the upper and lower sections of the deacidification and ammonia absorption tower 4. The steam and amino groups are condensed and absorbed. The acid gas coming out of the top of the deacidification and ammonia absorption tower 4 basically does not contain steam and ammonia, thus achieving separation of the acid gas from ammonia and steam; Step 3, ammonia distillation: The dilute ammonia water with low concentration at the bottom of the deacidification and ammonia absorption tower 4 is fed into the ammonia distillation tower 10. The bottom reboiler 11 is used to heat the bottom of the deacidification and ammonia absorption tower 4 to control the bottom temperature slightly below the saturation temperature of the ammonia distillation tower 10. At this time, the ammonia content in the bottom is already very low. The top temperature of the ammonia distillation tower 10 is controlled by reflux, and the ratio of ammonia gas and steam at the top of the tower is controlled to achieve the conversion of ammonia water into ammonia gas and steam. Step 4, ammonia production: When the ammonia concentration at the bottom of the ammonia reflux tower 7 is high, the reflux at the top of the ammonia evaporation tower 10 is reduced to increase the steam carried out of the ammonia evaporation tower 10, and the ammonia concentration is reduced after cooling through the ammonia reflux tower 7; when the ammonia concentration at the bottom of the ammonia reflux tower 7 is low, the reflux at the top of the ammonia evaporation tower 10 is increased to reduce the steam carried out of the ammonia evaporation tower 10, and the ammonia concentration is increased after cooling through the ammonia reflux tower 7.
[0028] Therefore, the present invention adopts the above-mentioned device and method for treating the conversion condensate. After two-stage cooling and washing in the deacidification and ammonia absorption tower, the acid gas emerging from the top of the deacidification and ammonia absorption tower is essentially free of steam and ammonia. The acid gas can be sent to the sulfur recovery combustion recovery treatment, and crystallization blockage of pipelines and equipment is also avoided. The amount of steam carried out from the top of the ammonia evaporation tower is adjusted by adjusting the reflux volume of the ammonia evaporation tower, thereby controlling the ammonia concentration without the need for additional water sources. By adding an ammonia evaporation tower and a reboiler and rationally controlling the tower bottom temperature, the ammonia nitrogen content of the condensate of the ammonia evaporation tower can be lower than that of the condensate of the stripping tower, further mitigating the accumulation of ammonia, nitrogen and other gases in the system caused by the condensate being returned to the vaporization and reuse.
[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A device for processing conversion condensate, characterized in that: It includes a stripping system, a deacidified gas system and an ammonia distillation system. The stripping system is connected to the deacidified gas system through a pipeline, and the deacidified gas system is connected to the ammonia distillation system.
2. A device for processing conversion condensate according to claim 1, characterized in that: The stripping system comprises a stripping tower, and the stripping tower is connected to a stripping tower kettle heat exchanger.
3. A device for processing conversion condensate according to claim 2, characterized in that: The deacidification gas system comprises a deacidification ammonia absorption tower, which is connected to the deacidification ammonia absorption tower kettle pump through a pipeline, the deacidification ammonia absorption tower kettle pump is respectively connected to the water cooler and the first heat exchanger through pipelines, and the water cooler is connected to the deacidification ammonia absorption tower through a pipeline.
4. The device for processing conversion condensate according to claim 3, characterized in that: The ammonia evaporation system includes an ammonia evaporation tower, which is connected to the first heat exchanger through a pipeline, the first heat exchanger is connected to the ammonia reflux tower through a pipeline, the ammonia reflux tower is connected to the ammonia pump and the deacidification and ammonia absorption tower through pipelines, and the kettle of the ammonia evaporation tower is provided with a reboiler.
5. The device for processing conversion condensate according to claim 4, characterized in that: The stripping tower kettle heat exchanger and the ammonia distillation tower are connected to the slag water system through pipelines.
6. The device for processing conversion condensate according to claim 3, characterized in that: The deacidification and ammonia absorption tower is connected to the sulfur recovery device.
7. The device for processing conversion condensate according to claim 4, characterized in that: The upper part of the ammonia reflux tower is divided into the condensation section and the reflux section.
8. The device for processing conversion condensate according to claim 4, characterized in that: A condensate cooler is installed on the pipeline connecting the ammonia evaporation tower and the deacidification and ammonia absorption tower.
9. A method for treating a conversion condensate, characterized in that: A device for processing a conversion condensate according to any one of claims 1 to 8 comprises the following steps: Step 1, stripping: In normal production, the stripping tower uses gasification low-flash gas. When the temperature of the tower bottom is difficult to raise, low-pressure steam is used to heat and strip the conversion condensate in the stripping tower to remove most of the ammonia and acid gas in the condensate. The purified process condensate at the bottom of the stripping tower is sent to the slag water system to separate the condensate from ammonia and acid gas. Step 2, ammonia absorption and deacidification: After the gas phase at the top of the stripping tower enters the deacidification and ammonia absorption tower, it is cooled and washed in the upper and lower sections of the deacidification and ammonia absorption tower, and the steam and amino are condensed and absorbed. The acid gas coming out of the top of the deacidification and ammonia absorption tower basically does not contain steam and ammonia, so the separation of acid gas from ammonia and steam is achieved; Step 3, ammonia evaporation: the dilute ammonia water with low concentration at the bottom of the deacidification ammonia absorption tower is sent to the ammonia evaporation tower, and the bottom reboiler is used to heat the deacidification ammonia absorption tower to control the tower bottom temperature to be slightly lower than the saturation temperature of the ammonia evaporation tower pressure. At this time, the ammonia content in the tower bottom is already very low. The top temperature of the ammonia evaporation tower is controlled by reflux, and the ratio of ammonia gas and steam at the top of the tower is controlled to realize the conversion of ammonia water into ammonia gas and steam. Step 4, ammonia production: when the ammonia concentration at the bottom of the ammonia reflux tower is high, the reflux at the top of the ammonia evaporation tower is reduced to increase the steam brought out of the ammonia evaporation tower, and the ammonia concentration is reduced after cooling in the ammonia reflux tower; when the ammonia concentration at the bottom of the ammonia reflux tower is low, the reflux at the top of the ammonia evaporation tower is increased to reduce the steam brought out of the ammonia evaporation tower, and the ammonia concentration is increased after cooling in the ammonia reflux tower.