Comprehensive recycling device and process for gaseous ammonia in synthetic ammonia tail gas

Abstract

The invention relates to the technical field of synthesis ammonia, in particular to a comprehensive recycling device and process for gaseous ammonia in synthesis ammonia tail gas. The device comprises: a preliminary separation module; an inlet of the washing recovery and circulation concentration module is connected with the preliminary separation module, and a liquid outlet is connected with the purification separation module; an inlet of the purification and separation module is connected with a liquid outlet of the washing, recycling and circulating concentration module, a gas outlet of the purification and separation module is connected with an inlet of the gas cooling module, and a liquid outlet of the purification and separation module is connected with an inlet of the absorption liquid cooling module; an outlet of the gas cooling module is connected with an inlet of the normal-pressure ammonia storage tank; an outlet of the absorption liquid cooling module is connected with an inlet of the washing recovery and circulating concentration module; an inlet of the ammonia water storage module is connected with a liquid outlet of the washing recovery and circulating concentration module and an outlet of the product ammonia supply module. The technical problem that in the prior art, a synthetic ammonia tail gas comprehensive utilization device cannot meet the tail gas recycling requirements in various different states is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic ammonia, and in particular to a device and process for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas. Background Art

[0002] The process of synthesizing ammonia produces tail gas mixed with hydrogen, nitrogen, ammonia, carbon monoxide, carbon dioxide and methane. The hydrogen, nitrogen and ammonia in the tail gas have high recycling value. By recycling these tail gases, not only can resources be reused and production costs reduced, but also environmental pollution can be reduced, and the environmental and social benefits of enterprises can be improved.

[0003] For example, the patent document with authorization announcement number CN204987654U discloses a comprehensive utilization device for synthetic ammonia tail gas, which includes a purification system, an ammonia recovery system, a re-purification system and a distillation system, wherein the purification system is used to purify the tail gas, the ammonia recovery system is used to liquefy the purified tail gas to obtain product liquid ammonia and gas after ammonia separation, the re-purification system is used to deammoniate and decarbonize the gas after ammonia separation, and the distillation system is used to distill the deammoniate and decarbonize gas.

[0004] It can be seen that the above device can utilize the tail gas generated in the process of synthetic ammonia. However, in the production process of synthetic ammonia, due to the process technology route, each system must discharge tail gas continuously or intermittently, and the flow rate, pressure, temperature and ammonia content of the tail gas discharged from different systems and different stages are different. It is necessary to select different recovery devices to recover the tail gas separately, which has high cost investment and low recovery efficiency. Summary of the invention

[0005] The present invention provides a device and process for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas, so as to solve the technical problem that the synthetic ammonia tail gas comprehensive utilization device in the prior art cannot meet the requirements for tail gas recovery and utilization under various conditions.

[0006] In order to solve the above problems, the device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas provided by the present invention adopts the following technical scheme:

[0007] A device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas, comprising:

[0008] A preliminary separation module, whose inlet is connected to the synthetic ammonia tail gas discharge outlet, whose gas outlet is connected to the inlet of the washing recovery and circulating concentration module, and whose liquid outlet is connected to the sewage treatment equipment, is used to separate the dust and liquid in the synthetic ammonia tail gas to obtain ammonia-containing tail gas and dust-containing liquid;

[0009] The washing recovery and circulating concentration module has a gas outlet connected to the incineration equipment and a liquid outlet connected to the purification and separation module, so as to wash the ammonia-containing tail gas and concentrate the ammonia in the ammonia-containing tail gas to obtain non-ammonia gas and ammonia water;

[0010] A purification and separation module, comprising an ammonia distillation tower feed heater, an ammonia distillation tower and an ammonia distillation tower bottom pump connected in sequence, wherein the inlets at both ends of the ammonia distillation tower feed heater are respectively connected to the liquid outlet of the washing recovery and circulation concentration module and the gas outlet at the top of the ammonia distillation tower, the top and bottom of the ammonia distillation tower are respectively provided with a first inlet and a second inlet, and the bottom end thereof has a liquid outlet, which is connected to the inlet of the absorption liquid cooling module, the inlet of the ammonia distillation tower bottom pump is connected to the liquid outlet of the ammonia distillation tower, the bottom of the ammonia distillation tower feed heater has two outlets respectively connected to the first inlet and the inlet of the gas cooling module, the second inlet is used to introduce steam, and the purification and separation module is used to separate ammonia water into gaseous ammonia and ammonia-containing absorption liquid;

[0011] A gas cooling module, whose gas outlet is connected to the ammonia compressor and whose liquid outlet is connected to the inlet of the atmospheric pressure ammonia storage tank;

[0012] An absorption liquid cooling module, the outlet of which is connected to the inlet of the washing recovery and circulating concentration module;

[0013] The inlet of the ammonia water storage module is connected with the liquid outlet of the washing recovery and circulating concentration module and the outlet of the product ammonia supply module.

[0014] The beneficial effects of the comprehensive recovery and utilization device of ammonia in synthetic ammonia tail gas provided by the present invention are:

[0015] 1. The dust and liquid in the synthetic ammonia tail gas from various sources are separated through the preliminary separation module to obtain ammonia-containing tail gas and dust-containing liquid. The ammonia in the ammonia-containing tail gas is concentrated through the washing recovery and circulation concentration module to obtain non-ammonia gas and ammonia water. The ammonia water is purified and separated through the purification and separation module to obtain gaseous ammonia and ammonia-containing absorption liquid. The gaseous ammonia is cooled and cooled through the gas cooling module, and the ammonia-containing absorption liquid is cooled and cooled through the absorption liquid cooling module, and then sent back to the washing recovery and circulation concentration module for recycling. A set of devices can be used to comprehensively recycle synthetic ammonia tail gas obtained under various different states, with a wide range of applications, and can improve the recovery efficiency of gaseous ammonia, not only can pure gaseous ammonia and high-concentration ammonia water be obtained, but also the energy consumption of tail gas incineration can be reduced, the circulation index of exhaust gas can be optimized, and the recycling of absorption liquid can be realized, so that zero waste liquid production and recycling of absorption liquid can be achieved in the process;

[0016] 2. The gas ammonia is cooled by the gas cooling module, and the cooled gas ammonia is sent to the ammonia compressor for recovery under the starting condition. Under the stopping condition, the obtained ammonia water with a concentration of 20% to 40% is transported to the atmospheric pressure ammonia storage tank for storage and sale. It can flexibly respond to changes in operating conditions and has wide applicability.

[0017] Through the above arrangement, the present invention effectively solves the technical problem that the comprehensive utilization device of synthetic ammonia tail gas in the prior art cannot meet the requirements of tail gas recovery and utilization under various conditions.

[0018] Furthermore, the synthetic ammonia tail gas includes tail gas emitted from cold ammonia storage tank, tail gas emitted from hot ammonia buffer storage tank, tail gas emitted from liquid ammonia loading truck, tail gas emitted from ammonia icing unit, tail gas emitted from synthesis gas unit, and high ammonia flash tail gas emitted from ammonia cooler / ammonia distribution tank / ammonia container.

[0019] Furthermore, the preliminary separation module comprises an exhaust gas separator tank, the inlet of which is connected to the synthetic ammonia tail gas exhaust outlet, the liquid outlet of which is connected to an exhaust gas condensate pump, and the outlet of the exhaust gas condensate pump is connected to the inlet of the sewage treatment equipment.

[0020] Furthermore, the washing recovery and circulation concentration module includes a main absorption tower, a main absorption tower circulation pump, a main absorption tower cooler, a tail gas washing tower and a tail gas washing tower bottom pump which are connected in sequence. The top and bottom of the main absorption tower are respectively provided with a third inlet and a fourth inlet, and the top end thereof has a gas outlet and the bottom end thereof has a liquid outlet, and the liquid outlet is connected to the inlet of the main absorption tower circulation pump. The top and bottom of the tail gas washing tower are respectively provided with a fifth inlet and a sixth inlet, and the top end thereof has a gas outlet and the bottom end thereof has a liquid outlet, the gas outlet of the main absorption tower is connected to the sixth inlet, the liquid outlet of the tail gas washing tower is connected to the inlet of the tail gas washing tower bottom pump, the outlet of the tail gas washing tower bottom pump is connected to the third inlet and the fifth inlet, and the fourth inlet is connected to the gas outlet of the preliminary separation module.

[0021] Furthermore, the gas cooling module includes a first circulating water cooler and a cooling separation tank, the inlet of the circulating water cooler is connected to the liquid outlet of the ammonia distillation tower feed heater, and the outlet is connected to the inlet opened on the side of the cooling separation tank. The top of the cooling separation tank is provided with an air outlet, and the bottom is provided with a liquid outlet. The air outlet of the cooling separation tank is connected to the ammonia compressor, and the liquid outlet is connected to the inlet of the atmospheric pressure ammonia storage tank.

[0022] Furthermore, the absorption liquid cooling module comprises a second circulating water cooler, the inlet of which is connected to the liquid outlet of the purification and separation module, and the outlet of which is connected to the inlet of the washing recovery and circulating concentration module.

[0023] Furthermore, the second circulating water cooler is a plate type circulating water cooler.

[0024] Furthermore, the ammonia water storage module includes an ammonia water storage tank, a mixer, a circulating cooler and an ammonia water pump. The inlet of the ammonia water storage tank is connected to the liquid outlet of the washing recovery and circulating concentration module and the outlet of the product ammonia supply module. The ammonia water pump is connected to the outlet of the ammonia water storage tank. The circulating cooler is arranged between the ammonia water storage tank and the ammonia water pump for circulating cooling of the ammonia water.

[0025] In order to solve the above problems, the comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas provided by the present invention adopts the following technical scheme:

[0026] A comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas comprises the following steps:

[0027] S1: The dust, liquid and ammonia-containing tail gas in the synthetic ammonia tail gas are separated through the preliminary separation module, and the separated ammonia-containing tail gas is discharged to the washing recovery and circulating concentration module, and the separated dust-containing liquid is discharged to the sewage treatment equipment;

[0028] S2: The ammonia in the ammonia-containing tail gas is concentrated by the washing recovery and circulating concentration module to obtain non-ammonia gas and ammonia water (concentration of 18%), and the non-ammonia gas is discharged to the incineration equipment through the gas outlet of the washing recovery and circulating concentration module, and a part of the ammonia water is transported back to the washing recovery and circulating concentration module for use as an absorption liquid, and the other part of the ammonia water is discharged from the liquid outlet of the washing recovery and circulating concentration module to the purification and separation module under the start-up condition, and is discharged from the liquid outlet of the washing recovery and circulating concentration module to the ammonia water storage system under the parking condition;

[0029] S3: After the ammonia water enters the ammonia still tower feed heater and exchanges heat with the outlet gas of the ammonia still tower to increase its temperature, it enters the ammonia still tower from the top of the ammonia still tower. The low-pressure steam with a pressure of P1 and a temperature of T1 introduced into the bottom of the ammonia still tower performs countercurrent contact heat exchange with the ammonia water, and the temperature of the top of the ammonia still tower is controlled to be T2. The gaseous ammonia with an ammonia content of 99.9% obtained at the top of the ammonia still tower is cooled to a temperature of T3 by the ammonia still tower feed heater and then sent to the gas cooling system. The absorption liquid with an ammonia content of 1.5% obtained at the bottom of the ammonia still tower is pressurized to a pressure of P2 by the ammonia still tower bottom pump and then sent to the absorption liquid cooling system. T1>T2>T3, P1>P2;

[0030] The ammonia water storage module mixes, pressurizes and cools the ammonia water delivered by the washing recovery and circulating concentration module with the liquid ammonia with a concentration of 99.99% delivered by the product ammonia supply module. After pressurizing to P3 pressure and cooling to T4 temperature, a part of the liquid ammonia flows back to the ammonia water storage module from the inlet of the ammonia water storage module, and the other part is sent out for loading;

[0031] S4: The gas cooling module circulates and cools the gas ammonia from the top of the ammonia evaporation tower and separates the gas and liquid. The separated ammonia gas is transported to the ammonia compressor for recovery. The separated condensed liquid ammonia (with a concentration of 99.9%) is transported to the atmospheric pressure ammonia storage tank for recovery. The condensed liquid in the atmospheric pressure ammonia storage tank is then pressurized to P3 pressure and then transported out.

[0032] The absorption liquid cooling module performs circulating cooling treatment on the ammonia-containing absorption liquid from the bottom of the ammonia distillation tower. After the ammonia-containing absorption liquid is cooled to the T4 temperature, it is transported to the washing recovery and circulating concentration system for recycling as the washing absorption liquid.

[0033] The beneficial effects of the comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas provided by the present invention are:

[0034] 1. The dust and liquid in the synthetic ammonia tail gas from various sources are separated through the preliminary separation module to obtain ammonia-containing tail gas and dust-containing liquid. The ammonia in the ammonia-containing tail gas is concentrated through the washing recovery and circulation concentration module to obtain non-ammonia gas and ammonia water. The ammonia water is purified and separated through the purification and separation module to obtain gaseous ammonia and ammonia-containing absorption liquid. The gaseous ammonia is cooled and cooled through the gas cooling module, and the ammonia-containing absorption liquid is cooled and cooled through the absorption liquid cooling module, and then sent back to the washing recovery and circulation concentration module for recycling. The synthetic ammonia tail gas obtained under various different states can be comprehensively recycled and utilized, with a wide range of applications, and the recovery efficiency of gaseous ammonia can be improved. Not only can pure gaseous ammonia and high-concentration ammonia water be obtained, but also the energy consumption of tail gas incineration can be reduced, the circulation index of exhaust gas can be optimized, and the recycling of absorption liquid can be realized, so that zero waste liquid production and recycling of absorption liquid can be achieved in the process;

[0035] 2. The gas ammonia is cooled by the gas cooling module, and the cooled gas ammonia is sent to the ammonia compressor for recovery under the starting condition. Under the stopping condition, the obtained ammonia water with a concentration of 20% to 40% is transported to the atmospheric pressure ammonia storage tank for storage and sale. It can flexibly respond to changes in operating conditions and has wide applicability.

[0036] Through the above arrangement, the present invention effectively solves the technical problem that the comprehensive utilization device of synthetic ammonia tail gas in the prior art cannot meet the requirements of tail gas recovery and utilization under various conditions.

[0037] Further, the pressure P1 is 0.6 MPa, the pressure P2 is 0.4 MPa, the pressure P3 is 0.7 MPa, the temperature T1 is 165°C, the temperature T2 is 85°C, the temperature T3 is 60°C, and the temperature T4 is 40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0039] Figure 1 This is a schematic diagram of the structure of the comprehensive recovery device of ammonia in synthetic ammonia tail gas provided by the present invention;

[0040] Figure 2 The present invention provides a flow chart of a comprehensive recovery process of ammonia in synthetic ammonia tail gas.

[0041] Description of reference numerals:

[0042] 11. Discharge gas separator tank; 12. Discharge gas condensate pump; 13. Sewage treatment equipment;

[0043] 21. Main absorption tower; 22. Main absorption tower circulation pump; 23. Main absorption tower cooler; 24. Tail gas washing tower; 25. Tail gas washing tower bottom pump;

[0044] 31. Ammonia still tower feed heater; 32. Ammonia still tower; 33. Ammonia still tower bottom pump;

[0045] 41. First circulating water cooler; 42. Cooling separation tank; 43. Normal pressure ammonia storage tank; 44. Cold ammonia pump;

[0046] 5. Second circulating water cooler;

[0047] 61. Ammonia water storage tank; 62. Circulating cooler; 63. Ammonia water pump; 64. Liquid ammonia storage tank. DETAILED DESCRIPTION

[0048] 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. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] After introducing the basic principle of the present invention, various non-limiting embodiments of the present invention are described in detail below. The number of any element in the drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning.

[0050] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0051] Embodiment 1 of the device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas provided by the present invention:

[0052] like Figure 1 As shown, the comprehensive recovery and utilization device of ammonia in synthetic ammonia tail gas includes a preliminary separation module, a washing recovery and circulating concentration module, a purification and separation module, a gas cooling module, an absorption liquid cooling module and an ammonia water storage module.

[0053] About the preliminary separation module. The preliminary separation module includes an exhaust gas separator tank 11, the inlet of which is connected to the exhaust outlet of synthetic ammonia tail gas, and the liquid outlet of which is connected to an exhaust gas condensate pump 12, and the outlet of the exhaust gas condensate pump 12 is connected to the inlet of a sewage treatment device 13. The preliminary separation module is used to separate dust and liquid from the synthetic ammonia tail gas to obtain ammonia-containing tail gas and dust-containing liquid.

[0054] Among them, synthetic ammonia exhaust gas includes exhaust gas emitted from cold ammonia storage tank, exhaust gas emitted from hot ammonia buffer storage tank, exhaust gas emitted from liquid ammonia loading truck, exhaust gas emitted from ammonia icing unit, exhaust gas emitted from synthesis gas unit, and high ammonia flash exhaust gas emitted from ammonia cooler / ammonia distribution tank / ammonia container.

[0055] About the washing recovery and circulating concentration module. The washing recovery and circulating concentration module includes a main absorption tower 21, a main absorption tower circulation pump 22, a main absorption tower cooler 23, a tail gas washing tower 24 and a tail gas washing tower bottom pump 25 connected in sequence. The top and bottom of the main absorption tower 21 are respectively provided with a third inlet and a fourth inlet, and the top end thereof has a gas outlet, and the bottom end thereof has a liquid outlet, and the liquid outlet is connected to the inlet of the main absorption tower circulation pump 22. The top and bottom of the tail gas washing tower 24 are respectively provided with a fifth inlet and a sixth inlet, and the top end thereof has a gas outlet, and the bottom end thereof has a liquid outlet, and the gas outlet of the main absorption tower 21 is connected to the sixth inlet, and the liquid outlet of the tail gas washing tower 24 is connected to the inlet of the tail gas washing tower bottom pump 25, and the outlet of the tail gas washing tower bottom pump 25 is connected to the third inlet and the fifth inlet, and the fourth inlet is connected to the gas outlet of the preliminary separation module.

[0056] Among them, the main absorption tower 21 and the tail gas washing tower 24 are both packed towers. The ammonia-containing tail gas enters the main absorption tower 21 from the bottom of the main absorption tower 21, and after reverse contact with the ammonia-containing absorption liquid in the main absorption tower 21, enters the tail gas washing tower 24 from the gas outlet at the top of the main absorption tower 21 through the sixth inlet, and then reversely contacts with the absorption liquid sprayed from the top of the tail gas washing tower 24 for washing. The tail gas obtained by washing enters the incineration equipment through the gas outlet at the top of the tail gas washing tower 24; the absorption liquid containing about 2% ammonia at the bottom of the tail gas washing tower 24 is pumped into the top of the main absorption tower 21 through the tail gas washing tower bottom pump 25. After the absorption liquid at the bottom of the main absorption tower 21 is pressurized by the main absorption tower circulation pump 22 and cooled by the main absorption tower cooler 23, a part of it is transported to the top of the main absorption tower 21 as the top circulating absorption liquid, and the other part is used as the product ammonia water (concentration 18%), which is sent to the purification and separation module under the start-up condition and to the ammonia water storage module under the parking condition.

[0057] In addition, desalted water is introduced from the top of the main absorption tower 21 and the tail gas washing tower 24 to wash the ammonia-containing tail gas.

[0058] About the purification and separation module. The purification and separation module includes an ammonia evaporation tower feed heater 31, an ammonia evaporation tower 32 and an ammonia evaporation tower bottom pump 33 which are connected in sequence. The inlets at both ends of the ammonia evaporation tower feed heater 31 are respectively connected to the liquid outlet of the washing recovery and circulation concentration module and the gas outlet at the top of the ammonia evaporation tower 32. The top and bottom of the ammonia evaporation tower 32 are respectively provided with a first inlet and a second inlet, and the bottom end thereof has a liquid outlet which is connected to the inlet of the absorption liquid cooling module. The inlet of the ammonia evaporation tower bottom pump 33 is connected to the liquid outlet of the ammonia evaporation tower 32. The bottom of the ammonia evaporation tower feed heater 31 has two outlets which are respectively connected to the first inlet and the inlet of the gas cooling module. The second inlet is used to introduce steam. The purification and separation module is used to separate ammonia water into gaseous ammonia and ammonia-containing absorption liquid.

[0059] Among them, the ammonia evaporation tower 32 adopts a packed tower; the product ammonia water (concentration 18%) enters the ammonia evaporation tower feed heater 31 and exchanges heat with the outlet gas of the ammonia evaporation tower 32 to increase the temperature, and then enters the ammonia evaporation tower 32 from the top of the ammonia evaporation tower 32. The ammonia evaporation tower 32 adopts 0.6MPa, 165℃ low-pressure steam entering the ammonia evaporation tower 32 from the second inlet as a heat source, and exchanges heat with the ammonia water in countercurrent contact, so that the temperature of the top of the ammonia evaporation tower 32 is controlled to be 85℃; the gaseous ammonia with a concentration of 99.9% obtained at the top of the ammonia evaporation tower 32 is cooled to 60℃ by the ammonia evaporation tower feed heater 31, and then sent to the gas cooling module, and the absorption liquid containing 1.5% ammonia obtained at the bottom of the ammonia evaporation tower 32 is pressurized to 0.4MPa by the ammonia evaporation tower bottom pump 33 and then sent to the absorption liquid cooling module.

[0060] About the gas cooling module. The gas cooling module includes a first circulating water cooler 41 and a cooling separation tank 42. The inlet of the circulating water cooler is connected to the liquid outlet of the ammonia distillation tower feed heater 31, and its outlet is connected to the inlet opened on the side of the cooling separation tank 42. The cooling separation tank 42 is provided with an air outlet at the top and a liquid outlet at the bottom. The air outlet of the cooling separation tank 42 is connected to the ammonia compressor, and its liquid outlet is connected to the inlet of the atmospheric pressure ammonia storage tank 43.

[0061] Among them, the gaseous ammonia from the ammonia evaporation tower 32 first enters the first circulating water cooler 41 for cooling and cooling, and then enters the cooling separation tank 42 for gas-liquid separation after the temperature drops to 40°C. The gaseous ammonia in the cooling separation tank 42 is transported from the gas outlet to the ammonia compressor for recovery, and the condensed liquid ammonia (concentration 99.9%) at the bottom of the cooling separation tank 42 is sent back to the atmospheric pressure ammonia storage tank 43 for recovery under the action of its own gravity, and the liquid ammonia is pressurized to 0.7MPa by the cold ammonia pump 44 connected to the liquid outlet of the atmospheric pressure ammonia storage tank 43 and then sent out.

[0062] Regarding the absorption liquid cooling module. The absorption liquid cooling module includes a second circulating water cooler 5, whose inlet is connected to the liquid outlet of the purification and separation module, and whose outlet is connected to the inlet of the washing recovery and circulating concentration module. Among them, the second circulating water cooler 5 is a plate-type circulating water cooler. After the absorption liquid from the ammonia distillation tower 32 enters the second circulating water cooler 5, it is cooled to 40°C and then sent to the washing recovery and circulating concentration module for recycling as the washing absorption liquid.

[0063] Regarding the ammonia water storage module. The ammonia water storage module includes an ammonia water storage tank 61, a mixer, a circulating cooler 62 and an ammonia water pump 63. The inlet of the ammonia water storage tank 61 is connected to the liquid outlet of the washing recovery and circulating concentration module and the outlet of the product ammonia supply module. The ammonia water pump 63 is connected to the outlet of the ammonia water storage tank 61. The circulating cooler 62 is arranged between the ammonia water storage tank 61 and the ammonia water pump 63 for circulating cooling of ammonia water.

[0064] Among them, the product ammonia water (concentration 18%) and the liquid ammonia (concentration 99.9%) delivered by the product supply module are mixed in the mixer and then enter the ammonia water storage tank 61. The ammonia water at the bottom of the ammonia water storage tank 61 is pressurized to 0.7MPa by the ammonia water pump 63 and then cooled to 40°C by the circulating cooler 62. Part of it flows back into the ammonia water storage tank 61, and part of it is sent out for loading; the product ammonia supply module is a liquid ammonia storage tank 64.

[0065] The working principle of the comprehensive recovery and utilization device of ammonia in synthetic ammonia tail gas provided by the present invention is:

[0066] First, the dust and liquid in the synthetic ammonia tail gas are separated by the exhaust gas separator 11 to obtain dust-containing liquid and ammonia-containing tail gas, and the dust-containing liquid is transported to the sewage treatment equipment 13 by the exhaust gas condensate pump 12;

[0067] Afterwards, the ammonia-containing tail gas enters the main absorption tower 21 from the bottom of the main absorption tower 21, contacts with the ammonia-containing absorption liquid in the main absorption tower 21 in reverse direction, and then enters the tail gas washing tower 24 from the gas outlet at the top of the main absorption tower 21 through the sixth inlet, and then contacts with the absorption liquid sprayed from the top of the tail gas washing tower 24 in reverse direction for washing, and the tail gas obtained by washing enters the incineration equipment through the gas outlet at the top of the tail gas washing tower 24; the absorption liquid containing about 2% ammonia at the bottom of the tail gas washing tower 24 is pumped into the top of the main absorption tower 21 through the tail gas washing tower bottom pump 25, and the absorption liquid at the bottom of the main absorption tower 21 is pressurized by the main absorption tower circulation pump 22 and cooled by the main absorption tower cooler 23, and a part of it is transported to the top of the main absorption tower 21 as the top circulating absorption liquid, and the other part is used as the product ammonia water (concentration 18%), which is sent to the purification and separation module in the start-up condition and to the ammonia water storage module in the parking condition;

[0068] Then, the product ammonia water (concentration 18%) enters the ammonia evaporation tower feed heater 31, exchanges heat with the outlet gas of the ammonia evaporation tower 32 to increase the temperature, and then enters the ammonia evaporation tower 32 from the top of the ammonia evaporation tower 32. The ammonia evaporation tower 32 uses 0.6MPa, 165°C low-pressure steam entering the ammonia evaporation tower 32 from the second inlet as a heat source, and exchanges heat with the ammonia water in countercurrent contact, and controls the temperature of the top of the ammonia evaporation tower 32 to be 85°C; the gaseous ammonia with a concentration of 99.9% obtained at the top of the ammonia evaporation tower 32 is cooled to 60°C by the ammonia evaporation tower feed heater 31 and sent to the gas cooling module, and the absorption liquid containing 1.5% ammonia obtained at the bottom of the ammonia evaporation tower 32 is pressurized to 0.4MPa by the ammonia evaporation tower bottom pump 33 and then sent to the absorption liquid cooling module;

[0069] Next, the gaseous ammonia from the ammonia evaporation tower 32 first enters the first circulating water cooler 41 for cooling and cooling, and after the temperature drops to 40°C, it enters the cooling separation tank 42 for gas-liquid separation. The gaseous ammonia in the cooling separation tank 42 is transported from the gas outlet to the ammonia compressor for recovery, and the condensed liquid ammonia (concentration 99.9%) at the bottom of the cooling separation tank 42 is sent back to the atmospheric pressure ammonia storage tank 43 for recovery under the action of its own gravity. The liquid ammonia is pressurized to 0.7MPa by the cold ammonia pump 44 connected to the liquid outlet of the atmospheric pressure ammonia storage tank 43 and then sent out; the absorption liquid from the ammonia evaporation tower 32 enters the second circulating water cooler 5, is cooled and cooled to 40°C, and then sent to the washing recovery and circulating concentration module for recycling as washing absorption liquid;

[0070] Finally, the product ammonia water (concentration 18%) and the liquid ammonia (concentration 99.9%) delivered from the product supply module are mixed in the mixer and enter the ammonia water storage tank 61. The ammonia water at the bottom of the ammonia water storage tank 61 is pressurized to 0.7 MPa by the ammonia water pump 63 and then cooled to 40°C by the circulating cooler 62. Part of it flows back into the ammonia water storage tank 61, and part of it is sent out for loading.

[0071] Embodiment 1 of the comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas provided by the present invention:

[0072] like Figure 2 As shown, the comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas includes the following steps:

[0073] S1: The dust, liquid and ammonia-containing tail gas in the synthetic ammonia tail gas are separated through the preliminary separation module, and the separated ammonia-containing tail gas is discharged to the washing recovery and circulating concentration module, and the separated dust-containing liquid is discharged to the sewage treatment equipment;

[0074] S2: The ammonia in the ammonia-containing tail gas is concentrated by the washing recovery and circulating concentration module to obtain non-ammonia gas and ammonia water (concentration of 18%), and the non-ammonia gas is discharged to the incineration equipment through the gas outlet of the washing recovery and circulating concentration module, and a part of the ammonia water is transported back to the washing recovery and circulating concentration module for use as an absorption liquid, and the other part of the ammonia water is discharged from the liquid outlet of the washing recovery and circulating concentration module to the purification and separation module under the start-up condition, and is discharged from the liquid outlet of the washing recovery and circulating concentration module to the ammonia water storage system under the parking condition;

[0075] S3: After the ammonia water enters the ammonia still tower feed heater and exchanges heat with the outlet gas of the ammonia still tower to increase its temperature, it enters the ammonia still tower from the top of the ammonia still tower. The low-pressure steam with a pressure of P1 and a temperature of T1 introduced into the bottom of the ammonia still tower performs countercurrent contact heat exchange with the ammonia water, and the temperature of the top of the ammonia still tower is controlled to be T2. The gaseous ammonia with an ammonia content of 99.9% obtained at the top of the ammonia still tower is cooled to a temperature of T3 by the ammonia still tower feed heater and then sent to the gas cooling system. The absorption liquid with an ammonia content of 1.5% obtained at the bottom of the ammonia still tower is pressurized to a pressure of P2 by the ammonia still tower bottom pump and then sent to the absorption liquid cooling system. T1>T2>T3, P1>P2;

[0076] The ammonia water storage module mixes, pressurizes and cools the ammonia water delivered by the washing recovery and circulating concentration module with the liquid ammonia with a concentration of 99.99% delivered by the product ammonia supply module. After pressurizing to P3 pressure and cooling to T4 temperature, a part of the liquid ammonia flows back to the ammonia water storage module from the inlet of the ammonia water storage module, and the other part is sent out for loading;

[0077] S4: The gas cooling module circulates and cools the gas ammonia from the top of the ammonia evaporation tower and separates the gas and liquid. The separated ammonia gas is transported to the ammonia compressor for recovery. The separated condensed liquid ammonia (with a concentration of 99.9%) is transported to the atmospheric pressure ammonia storage tank for recovery. The condensed liquid in the atmospheric pressure ammonia storage tank is then pressurized to P3 pressure and then transported out.

[0078] The absorption liquid cooling module performs circulating cooling treatment on the ammonia-containing absorption liquid from the bottom of the ammonia distillation tower. After the ammonia-containing absorption liquid is cooled to the T4 temperature, it is transported to the washing recovery and circulating concentration system for recycling as the washing absorption liquid.

[0079] Among them, pressure P1 is 0.6 MPa, pressure P2 is 0.4 MPa, pressure P3 is 0.7 MPa, temperature T1 is 165°C, temperature T2 is 85°C, temperature T3 is 60°C, and temperature T4 is 40°C.

[0080] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and the like, which indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0081] In addition, in the description of this specification, “plurality” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas, characterized in that: include: A preliminary separation module, whose inlet is connected to the synthetic ammonia tail gas discharge outlet, whose gas outlet is connected to the inlet of the washing recovery and circulating concentration module, and whose liquid outlet is connected to the sewage treatment equipment, is used to separate the dust and liquid in the synthetic ammonia tail gas to obtain ammonia-containing tail gas and dust-containing liquid; The washing recovery and circulating concentration module has a gas outlet connected to the incineration equipment and a liquid outlet connected to the purification and separation module, so as to wash the ammonia-containing tail gas and concentrate the ammonia in the ammonia-containing tail gas to obtain non-ammonia gas and ammonia water; A purification and separation module, comprising an ammonia distillation tower feed heater, an ammonia distillation tower and an ammonia distillation tower bottom pump connected in sequence, wherein the inlets at both ends of the ammonia distillation tower feed heater are respectively connected to the liquid outlet of the washing recovery and circulation concentration module and the gas outlet at the top of the ammonia distillation tower, the top and bottom of the ammonia distillation tower are respectively provided with a first inlet and a second inlet, and the bottom end thereof has a liquid outlet, which is connected to the inlet of the absorption liquid cooling module, the inlet of the ammonia distillation tower bottom pump is connected to the liquid outlet of the ammonia distillation tower, the bottom of the ammonia distillation tower feed heater has two outlets respectively connected to the first inlet and the inlet of the gas cooling module, the second inlet is used to introduce steam, and the purification and separation module is used to separate ammonia water into gaseous ammonia and ammonia-containing absorption liquid; A gas cooling module, whose gas outlet is connected to the ammonia compressor and whose liquid outlet is connected to the inlet of the atmospheric pressure ammonia storage tank; The outlet of the absorption liquid cooling module is connected to the inlet of the washing recovery and circulating concentration module; the inlet of the ammonia water storage module is connected to the liquid outlet of the washing recovery and circulating concentration module and the outlet of the product ammonia supply module.

2. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1, characterized in that: The synthetic ammonia tail gas includes tail gas emitted from cold ammonia storage tank, tail gas emitted from hot ammonia buffer storage tank, tail gas emitted from liquid ammonia loading truck, tail gas emitted from ammonia refrigeration unit, tail gas emitted from synthesis gas unit, and high ammonia flash tail gas emitted from ammonia cooler / ammonia distribution tank / ammonia container.

3. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1 or 2, characterized in that: The preliminary separation module comprises an exhaust gas separator tank, the inlet of which is connected to the synthetic ammonia tail gas exhaust outlet, the liquid outlet of which is connected to an exhaust gas condensate pump, and the outlet of the exhaust gas condensate pump is connected to the inlet of the sewage treatment equipment.

4. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1 or 2, characterized in that: The washing recovery and circulating concentration module comprises a main absorption tower, a main absorption tower circulation pump, a main absorption tower cooler, a tail gas washing tower and a tail gas washing tower bottom pump which are connected in sequence. The top and bottom of the main absorption tower are respectively provided with a third inlet and a fourth inlet, and the top end thereof has a gas outlet, and the bottom end thereof has a liquid outlet, and the liquid outlet is connected to the inlet of the main absorption tower circulation pump. The top and bottom of the tail gas washing tower are respectively provided with a fifth inlet and a sixth inlet, and the top end thereof has a gas outlet, and the bottom end thereof has a liquid outlet, the gas outlet of the main absorption tower is connected to the sixth inlet, the liquid outlet of the tail gas washing tower is connected to the inlet of the tail gas washing tower bottom pump, the outlet of the tail gas washing tower bottom pump is connected to the third inlet and the fifth inlet, and the fourth inlet is connected to the gas outlet of the preliminary separation module.

5. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1 or 2, characterized in that: The gas cooling module includes a first circulating water cooler and a cooling separation tank, the inlet of the circulating water cooler is connected to the liquid outlet of the ammonia distillation tower feed heater, and the outlet is connected to the inlet opened on the side of the cooling separation tank. The top of the cooling separation tank is provided with an air outlet, and the bottom is provided with a liquid outlet. The air outlet of the cooling separation tank is connected to the ammonia compressor, and the liquid outlet is connected to the inlet of the atmospheric pressure ammonia storage tank.

6. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1 or 2, characterized in that: The absorption liquid cooling module comprises a second circulating water cooler, the inlet of which is connected to the liquid outlet of the purification and separation module, and the outlet of which is connected to the inlet of the washing recovery and circulating concentration module.

7. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 6, characterized in that: The second circulating water cooler is a plate type circulating water cooler.

8. The device for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 1 or 2, characterized in that: The ammonia water storage module includes an ammonia water storage tank, a mixer, a circulating cooler and an ammonia water pump. The inlet of the ammonia water storage tank is connected to the liquid outlet of the washing recovery and circulating concentration module and the outlet of the product ammonia supply module. The ammonia water pump is connected to the outlet of the ammonia water storage tank. The circulating cooler is arranged between the ammonia water storage tank and the ammonia water pump for circulating cooling of the ammonia water.

9. A comprehensive recovery and utilization process of ammonia in synthetic ammonia tail gas, characterized in that: The comprehensive recovery and utilization device of ammonia in synthetic ammonia tail gas according to any one of claims 1 to 8 is implemented, comprising the following steps: S1: The dust, liquid and ammonia-containing tail gas in the synthetic ammonia tail gas are separated through the preliminary separation module, and the separated ammonia-containing tail gas is discharged to the washing recovery and circulating concentration module, and the separated dust-containing liquid is discharged to the sewage treatment equipment; S2: The ammonia in the ammonia-containing tail gas is concentrated by the washing recovery and circulating concentration module to obtain non-ammonia gas and ammonia water (concentration of 18%), and the non-ammonia gas is discharged to the incineration equipment through the gas outlet of the washing recovery and circulating concentration module, and a part of the ammonia water is transported back to the washing recovery and circulating concentration module for use as an absorption liquid, and the other part of the ammonia water is discharged from the liquid outlet of the washing recovery and circulating concentration module to the purification and separation module under the start-up condition, and is discharged from the liquid outlet of the washing recovery and circulating concentration module to the ammonia water storage system under the parking condition; S3: After the ammonia water enters the ammonia still tower feed heater and exchanges heat with the outlet gas of the ammonia still tower to increase its temperature, it enters the ammonia still tower from the top of the ammonia still tower. The low-pressure steam with a pressure of P1 and a temperature of T1 introduced into the bottom of the ammonia still tower performs countercurrent contact heat exchange with the ammonia water, and the temperature of the top of the ammonia still tower is controlled to be T2. The gaseous ammonia with an ammonia content of 99.9% obtained at the top of the ammonia still tower is cooled to a temperature of T3 by the ammonia still tower feed heater and then sent to the gas cooling system. The absorption liquid with an ammonia content of 1.5% obtained at the bottom of the ammonia still tower is pressurized to a pressure of P2 by the ammonia still tower bottom pump and then sent to the absorption liquid cooling system. T1>T2>T3, P1>P2; The ammonia water storage module mixes, pressurizes and cools the ammonia water delivered by the washing recovery and circulating concentration module with the liquid ammonia with a concentration of 99.99% delivered by the product ammonia supply module. After pressurizing to P3 pressure and cooling to T4 temperature, a part of the liquid ammonia flows back to the ammonia water storage module from the inlet of the ammonia water storage module, and the other part is sent out for loading; S4: The gas cooling module circulates and cools the gas ammonia from the top of the ammonia evaporation tower and separates the gas and liquid. The separated ammonia gas is transported to the ammonia compressor for recovery. The separated condensed liquid ammonia (with a concentration of 99.9%) is transported to the atmospheric pressure ammonia storage tank for recovery. The condensed liquid in the atmospheric pressure ammonia storage tank is then pressurized to P3 pressure and then transported out. The absorption liquid cooling module performs circulating cooling treatment on the ammonia-containing absorption liquid from the bottom of the ammonia distillation tower. After the ammonia-containing absorption liquid is cooled to the T4 temperature, it is transported to the washing recovery and circulating concentration system for recycling as the washing absorption liquid.

10. The process for comprehensive recovery and utilization of ammonia in synthetic ammonia tail gas according to claim 9, characterized in that: The pressure P1 is 0.6 MPa, the pressure P2 is 0.4 MPa, the pressure P3 is 0.7 MPa, the temperature T1 is 165°C, the temperature T2 is 85°C, the temperature T3 is 60°C, and the temperature T4 is 40°C.

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