Apparatus for ammonia recycle absorption in hydrocyanic acid

Abstract

The utility model discloses a device of ammonia circulation absorption in hydrocyanic acid, including ammonia absorption tower, decyanation tower, deamination tower, ammonia water buffer jar, ammonia water storage jar that connect in proper order, ammonia absorption tower top is equipped with deamination synthesis gas export, and ammonia absorption tower bottom output is divided into two ways, one way connects ammonia absorption tower tower kettle circulating pump, ammonia absorption tower cooler, and the other way connects ammonia absorption tower tower kettle production pump, and decyanation tower top is equipped with cyanogen containing steam export, and decyanation tower bottom output is divided into two ways, one way connects decyanation tower tower kettle circulating pump, decyanation tower tower kettle reboiler, and the other way connects decyanation tower tower kettle production pump, and decyanation tower top is equipped with ammonia containing steam export, and deamination tower bottom output is divided into two ways, one way circularly connects deamination tower tower kettle circulating pump, deamination tower tower kettle reboiler, and the other way connects deamination tower tower kettle production pump, deamination tower tower kettle cooler, the device of the utility model has solved the problem of safety risk to the operator and the process in the production process of existing hydrocyanic acid using sulfuric acid to absorb ammonia.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a device for the recycling and absorption of ammonia in hydrogen cyanide. Background Technology

[0002] Hydrogen cyanide is a common chemical in industrial production. It is highly toxic and easily volatilizes into the air. It can enter the human body through the skin, respiratory tract, and digestive tract, causing acute health problems and even death to operators exposed to it. Liquid hydrogen cyanide readily polymerizes under light, in ammonia-containing, and iron-containing environments, turning into a yellow solution or a dark brown solid.

[0003] The method for preparing hydrogen cyanide involved in this invention involves the pyrolysis of formamide to produce hydrogen cyanide and water. However, a small amount of ammonia and carbon monoxide are generated as side reactions during the pyrolysis of formamide. The syngas from the hydrogen cyanide produced by the pyrolysis of formamide contains a small amount of ammonia, which can easily cause the liquid hydrogen cyanide to polymerize and explode. Currently, the main method involves absorbing ammonia with sulfuric acid solution and then condensing the hydrogen cyanide. The sulfuric acid absorbent needs to undergo decyanation, concentration, and crystallization to produce ammonium sulfate as a byproduct. This method is complex, costly, and increases the risk of personnel exposure to the working environment, posing safety hazards to personnel and process safety.

[0004] Therefore, it is necessary to design a device for the recycling and absorption of ammonia in hydrogen cyanide to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a device for the cyclic absorption of ammonia in hydrogen cyanide. This solves the safety hazard problem associated with existing hydrogen cyanide production processes that use sulfuric acid to absorb ammonia.

[0006] The technical solution adopted in this utility model is as follows: a device for the cyclic absorption of ammonia in hydrogen cyanide, comprising an ammonia absorption tower, a decyanation tower, a deammoniation tower, an ammonia water buffer tank, and an ammonia water storage tank connected in sequence. The ammonia absorption tower has a deammoniation synthesis gas outlet at the top and an ammonia-containing synthesis gas inlet in the middle. The output at the bottom of the ammonia absorption tower is divided into two paths: one path is sequentially connected to the ammonia absorption tower bottom circulation pump and the ammonia absorption tower cooler and circulated to the top of the ammonia absorption tower; the other path is connected to the ammonia absorption tower bottom outlet pump. The decyanation tower has a cyanide vapor outlet at the top, which is connected to the decyanation tower top condenser. The inlet of the decyanation tower is divided into two paths at the bottom. One path is sequentially connected to the decyanation tower bottom circulation pump and the decyanation tower bottom reboiler, and then circulated to the middle of the decyanation tower. The other path is connected to the decyanation tower bottom outlet pump. The top of the deammonia removal tower is equipped with an ammonia-containing vapor outlet, which is sequentially connected to the deammonia removal tower top condenser, ammonia water buffer tank, and ammonia water storage tank. The bottom outlet of the deammonia removal tower is divided into two paths. One path is sequentially connected to the deammonia removal tower bottom circulation pump and the deammonia removal tower bottom reboiler, and then circulated to the middle of the deammonia removal tower. The other path is sequentially connected to the deammonia removal tower bottom outlet pump and the deammonia removal tower bottom cooler.

[0007] The technical solution adopted in this utility model is also characterized by:

[0008] Furthermore, the ammonia absorption tower is equipped with a wire mesh demister a, a spray plate a, a water distribution pipe a, a Pall ring packing c, a Pall ring packing b, and a structured packing a from top to bottom. The lower side wall of the ammonia absorption tower is equipped with an online pH analyzer a and a temperature analyzer a. The deammoniation-removed syngas is discharged through the deammoniation-removed syngas outlet at the top of the ammonia absorption tower.

[0009] The ammonia-containing synthesis gas inlet is located between Pall ring packing b and structured packing a;

[0010] The ammonia-containing synthesis gas inlet is divided into two paths: one path is connected to the ammonia-containing hydrogen cyanide synthesis gas inlet valve c, and the other path is connected to the top condenser of the decyanation tower through the outlet valve b.

[0011] The top condenser of the decyanation tower is equipped with a circulating water inlet valve b and a circulating water outlet valve a on both sides.

[0012] The bottom outlet of the ammonia absorption tower is divided into two paths. One path is connected to the ammonia absorption tower cooler and the pipeline is connected to the ammonia absorption liquid inlet valve. The other path is connected to the spray plate b in the middle of the decyanation tower via the ammonia absorption tower bottom pump and the pipeline is connected to the programmable valve a and valve e.

[0013] The ammonia absorption tower cooler is equipped with a circulating water inlet valve a and a circulating water outlet control valve, and circulating water is introduced into the ammonia absorption tower cooler;

[0014] The pH online analyzer a is associated with the programmable valve a on the outlet pipeline of the ammonia absorption tower bottom pump, and the pH online analyzer a controls the pH of the ammonia absorption tower bottom liquid;

[0015] Temperature analyzer a is associated with the circulating water outlet control valve of the ammonia absorption tower cooler. The circulating water outlet control valve automatically opens or closes according to the temperature of temperature analyzer a to control the temperature of the ammonia absorption tower bottom.

[0016] Furthermore, fixed nozzles a are evenly distributed on the spray plate a, and valve a is connected to the deammoniation synthesis gas outlet.

[0017] Furthermore, the interior of the decyanation tower is arranged from top to bottom as follows: wire mesh demister b, Pall ring packing d, spray plate b, water distribution pipe b, and structured packing b. The cyanide-containing vapor is discharged through the cyanide-containing vapor outlet at the top of the decyanation tower.

[0018] The steam inlet of the reboiler in the decyanation tower is associated with the programmable valve b, which is associated with the temperature analyzer b. A condensate valve a is installed at the bottom of the reboiler in the decyanation tower. The temperature analyzer b is connected to the side wall of the decyanation tower bottom to detect the temperature of the liquid in the decyanation tower bottom and to adjust the temperature of the decyanation tower bottom.

[0019] The reboiler in the decyanation tower uses steam as a heat source. The Pall ring packing (d) has two rows of staggered windows on its ring wall. Each row has five tongues, each pointing towards the ring center. The structured packing (b) is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 30°.

[0020] Furthermore, atomizing fixed nozzles b are evenly distributed on the spray plate b, and a valve d is connected to the cyanide-containing vapor outlet at the top of the decyanation tower;

[0021] The outlet of cyanide-containing vapor is linked to the inlet of the top condenser of the decyanation tower. The shell side of the top condenser of the decyanation tower conveys cyanide-containing vapor, and the tube side conveys circulating water. Circulating water is introduced into the top condenser of the decyanation tower.

[0022] The spray plate b pipeline connects to two inlet pipelines. One inlet pipeline is connected to the outlet of the ammonia absorption tower bottom pump via valve e, and the other inlet pipeline is connected to the outlet of the decyanation tower bottom reboiler via the decyanation tower bottom circulation pump.

[0023] An inlet valve for the decyanation tower circulating pump is installed on the inlet pipeline of the decyanation tower bottom circulation pump, and an outlet valve for the decyanation tower circulating pump is installed on the outlet pipeline.

[0024] Furthermore, the interior of the ammonia removal tower is arranged from top to bottom as follows: wire mesh demister c, spray plate d, water distribution pipe d, structured packing d, spray plate c, water distribution pipe c, structured packing c; and an online pH analyzer b is installed on the lower side wall of the ammonia removal tower.

[0025] Structured packing d is vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 45°; the structured packing c is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 30°.

[0026] The ammonia vapor outlet is connected to valve g, valve g is connected to the inlet of the top condenser of the ammonia removal tower, circulating water is introduced into the top condenser of the ammonia removal tower, the outlet of the top condenser of the ammonia removal tower is connected to the inlet of the ammonia water buffer tank, and circulating water inlet valve c and circulating water outlet valve b are respectively installed on both sides of the top condenser of the ammonia removal tower.

[0027] The outlet of the condenser at the top of the deammoniation tower is connected to the inlet of the ammonia buffer tank, and a valve for the outlet of the condenser at the top of the deammoniation tower is installed on the pipeline.

[0028] Furthermore, atomizing fixed nozzles c are evenly distributed on the spray plate c. The inlet pipeline of the spray plate c is divided into two paths. One path is connected sequentially to valve f and the outlet of the decyanation tower bottom pump, and the other path is connected to the outlet of the deammoniation tower bottom reboiler.

[0029] The steam inlet of the reboiler in the deammoniation tower is equipped with a programmable valve c, and the lower part of the reboiler in the deammoniation tower is equipped with a condensate valve b. The steam inlet of the reboiler in the deammoniation tower is associated with the programmable valve c, and the programmable valve c is associated with the pH online analyzer b. The programmable valve c controls the temperature of the liquid in the bottom of the deammoniation tower.

[0030] Atomizing fixed nozzles d are evenly distributed on the spray plate d, and the spray plate d is connected to the outlet of the ammonia water circulation pump.

[0031] Furthermore, the bottom output of the ammonia absorption tower is divided into two paths: one path is connected to the circulating pump of the ammonia absorption tower bottom, passes through the ammonia absorption tower cooler, and goes to the spray plate a; the other path is connected to the ammonia absorption tower bottom outlet pump and goes to the spray plate b in the middle of the decyanation tower.

[0032] The bottom output of the decyanation tower is divided into two paths. One path is connected to the decyanation tower bottom circulation pump, which passes through the decyanation tower bottom reboiler to the spray plate b. The other path is connected to the decyanation tower bottom outlet pump to the spray plate c in the middle of the deammonia removal tower.

[0033] The bottom output of the ammonia stripping tower is divided into two paths. One path is connected to the reboiler of the ammonia stripping tower via the reboiler to the spray plate c. The other path is connected to the outlet pump of the ammonia stripping tower via the cooler to the outlet pipeline of the reboiler pump of the ammonia absorption tower.

[0034] An outlet valve for the ammonia absorption tower circulating pump is installed on the outlet pipeline of the circulating pump at the bottom of the ammonia absorption tower, and an inlet valve for the circulating pump at the bottom of the ammonia absorption tower is installed on the inlet pipeline of the circulating pump at the bottom of the ammonia absorption tower.

[0035] The inlet pipeline of the decyanation tower bottom pump is equipped with an inlet valve, and the outlet pipeline is equipped with an outlet valve.

[0036] An inlet valve for the deammoniation tower circulating pump is installed on the inlet pipeline of the deammoniation tower bottom circulating pump, and an outlet valve for the deammoniation tower circulating pump is installed on the outlet pipeline.

[0037] An inlet valve for the deammoniation tower bottom pump is installed on the inlet pipeline, and an outlet valve for the deammoniation tower bottom pump is installed on the outlet pipeline.

[0038] Furthermore, circulating water is introduced into the deammoniation tower bottom cooler to cool the ammonia absorption liquid that has regained its ammonia absorption capacity. The top of the deammoniation tower bottom cooler is equipped with a deammoniation tower bottom cooler outlet, which is connected to the ammonia absorption liquid inlet valve. The upper part of the deammoniation tower bottom cooler is equipped with a programmable valve e, and the lower part is equipped with a condensate valve c.

[0039] Furthermore, the bottom of the ammonia buffer tank is equipped with an ammonia circulation outlet and an ammonia collection outlet. The ammonia circulation outlet is connected to the inlet of the ammonia circulation pump to deliver low-concentration ammonia back to the spray plate d. An ammonia circulation pump inlet valve for the ammonia removal tower is installed at the inlet of the ammonia circulation pump. The ammonia collection outlet is connected to the inlet of the ammonia collection pump. An ammonia collection pump inlet valve for the ammonia removal tower is installed at the inlet of the ammonia collection pump.

[0040] The ammonia storage tank is equipped with a concentrated ammonia inlet, which is connected to the outlet of the ammonia extraction pump. A programmable valve d is installed on the pipeline.

[0041] An online ammonia analyzer is installed on the side wall of the ammonia buffer tank, and the online ammonia analyzer is associated with the programmable valve d;

[0042] The ammonia water outlet is connected to the ammonia water extraction pump to transport high-concentration ammonia water to the ammonia water storage tank.

[0043] The beneficial effects of this utility model are:

[0044] This invention removes ammonia from hydrogen cyanide synthesis gas to obtain 85%-98% hydrogen cyanide gas phase and 0%-10% ammonia water, thereby achieving continuous production of hydrogen cyanide. It also improves the safe and efficient use of hydrogen cyanide chemicals in industrial production, recovers ammonia from hydrogen cyanide synthesis gas, increases ammonia recovery rate, saves costs, and protects the environment, thus achieving significant practical value and economic benefits.

[0045] This invention relates to a device that removes ammonia from hydrogen cyanide synthesis gas to obtain 85%-98% hydrogen cyanide and 0%-10% ammonia solution. This solution can be applied to the industrial production of cyanide and concentrated ammonia to achieve safe and efficient use of hydrogen cyanide chemicals, reduce the ammonia content in hydrogen cyanide, and improve the utilization rate of both hydrogen cyanide and ammonia. Simultaneously, it saves costs and protects the environment. It also alleviates the problems of hydrogen cyanide instability, easy polymerization, unsafe use, and difficulty in continuous production in industrial applications. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the device of this utility model.

[0047] In the diagram, 1. Ammonia absorption tower, 2. Cyanide removal tower, 3. Ammonia removal tower, 4. Ammonia water buffer tank, 5. Ammonia water storage tank, 6. Ammonia absorption tower cooler, 7. Circulating water inlet valve a, 8. Ammonia absorption liquid inlet valve, 9. Ammonia absorption tower circulating pump outlet valve, 10. Ammonia absorption tower bottom circulating pump, 11. Ammonia absorption tower circulating pump inlet valve, 12. Ammonia absorption tower outlet pump inlet valve, 13. Circulating water outlet control valve, 14. Pall ring packing b, 15. Valve a, 16. Ammonia removal synthesis gas outlet, 17. Wire mesh demister a, 18. Fixed nozzle a, 19. Spray plate a, 20. Water distribution pipe a, 21. Pall ring packing c, 22. Valve b, 23. Ammonia-containing synthesis gas inlet, 24. Structured packing a, 2 5. Valve c; 26. Condenser at the top of the decyanation tower; 27. Circulating water inlet valve b; 28. Circulating water outlet valve a; 29. ​​Valve d; 30. Cyanide vapor outlet; 31. Wire mesh demister b; 32. Pall ring packing d; 33. Valve e; 34. Spray plate b; 35. Water distribution pipe b; 36. Fixed nozzle b; 37. Structured packing b; 38. Temperature analyzer a; 39. Online pH analyzer a; 40. Programmable valve a; 41. Ammonia absorption tower bottom pump; 42. Decyanation tower bottom circulation pump; 43. Decyanation tower circulation pump inlet valve; 44. Decyanation tower bottom pump inlet valve; 45. Decyanation tower bottom pump; 46. Decyanation tower bottom pump outlet valve; 47. Decyanation tower circulation pump outlet valve. 48. Temperature analyzer b; 49. Condensate valve a; 50. Programmable valve b; 51. Reboiler at the bottom of the decyanation tower; 52. Circulating pump at the bottom of the deammoniation tower; 53. Inlet valve of the circulating pump at the deammoniation tower; 54. Inlet valve of the discharge pump at the deammoniation tower; 55. Discharge pump at the bottom of the deammoniation tower; 56. Outlet valve of the circulating pump at the deammoniation tower; 57. Condensate valve b; 58. Online pH analyzer b; 59. Reboiler at the bottom of the deammoniation tower; 60. Programmable valve c; 61. Valve f; 62. Spray tray c; 63. Water distribution pipe c; 64. Structured packing c; 65. Fixed nozzle c; 66. Structured packing d; 67. Water distribution pipe d; 68. Fixed nozzle d; 69. Spray tray d; 70. Wire mesh demister c; 71. Containing Ammonia vapor outlet, 72. Valve g, 73. Deammoniation tower top condenser, 74. Circulating water inlet valve c, 75. Circulating water outlet valve b, 76. Deammoniation tower top condenser outlet valve, 77. Ammonia water buffer tank inlet, 78. Ammonia water circulation pump, 79. Deammoniation tower ammonia water circulation pump inlet valve, 80. Ammonia water circulation outlet, 81. Ammonia water collection outlet, 82. Ammonia water online analyzer, 83. Programmable control valve d, 84. Deammoniation tower ammonia water collection pump inlet valve, 85. Ammonia water collection pump, 86. Concentrated ammonia water inlet valve, 87. Concentrated ammonia water inlet, 88. Deammoniation tower bottom cooler, 89. Deammoniation tower collection pump outlet valve, 90. Condensate valve c, 91. Programmable control valve e, 92. Deammoniation tower bottom cooler outlet. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0049] This invention provides a device for the recycling and absorption of ammonia in hydrogen cyanide, which recovers and utilizes ammonia entrained in hydrogen cyanide synthesis gas to obtain hydrogen cyanide and ammonia water with higher purity. This improves the purity of hydrogen cyanide and the recycling of ammonia in hydrogen cyanide synthesis gas, promotes the safety of hydrogen cyanide use and the utilization rate of ammonia. At the same time, it enhances the safety of industrial use of hydrogen cyanide, saves costs and protects the environment, achieving significant economic and social benefits.

[0050] The device for the cyclic absorption of ammonia in hydrogen cyanide includes, in sequence, an ammonia absorption tower 1, a decyanation tower 2, a deammoniation tower 3, an ammonia water buffer tank 4, and an ammonia water storage tank 5. The ammonia absorption tower 1 has a deammoniation synthesis gas outlet 16 at its top and an ammonia-containing synthesis gas inlet 23 in its middle. The bottom output of the ammonia absorption tower 1 is divided into two paths: one path is sequentially connected to the ammonia absorption tower bottom circulation pump 10 and the ammonia absorption tower cooler 6, and then circulated to the top of the ammonia absorption tower 1; the other path is connected to the ammonia absorption tower bottom outlet pump 41. The decyanation tower 2 has a cyanide vapor outlet 30 at its top, which is connected to the inlet of the decyanation tower top condenser 26. The bottom of the decyanation tower 2... The output of the decyanation tower 2 is divided into two paths. One path is sequentially connected to the decyanation tower bottom circulation pump 42 and the decyanation tower bottom reboiler 51 and is circulated to the middle of the decyanation tower 2. The other path is connected to the decyanation tower bottom outlet pump 45. The top of the deammonia removal tower 3 is provided with an ammonia vapor outlet 71. The ammonia vapor outlet 71 is sequentially connected to the deammonia removal tower top condenser 73, the ammonia water buffer tank 4, and the ammonia water storage tank 5. The bottom output of the deammonia removal tower 3 is divided into two paths. One path is sequentially connected to the deammonia removal tower bottom circulation pump 52 and the deammonia removal tower bottom reboiler 59 and is circulated to the middle of the deammonia removal tower 3. The other path is sequentially connected to the deammonia removal tower bottom outlet pump 55 and the deammonia removal tower bottom cooler 88.

[0051] The ammonia absorption tower 1 is equipped with a wire mesh demister a17, a spray plate a19, a water distribution pipe a20, a Pall ring packing c21, a Pall ring packing b14, and a structured packing a24 from top to bottom. The lower side wall of the ammonia absorption tower 1 is equipped with an online pH analyzer a39 and a temperature analyzer a38. The deammoniation-removed syngas is discharged through the deammoniation-removed syngas outlet 16 at the top of the ammonia absorption tower.

[0052] The ammonia-containing synthesis gas inlet 23 is located between Pall ring packing b14 and structured packing a24;

[0053] The ammonia-containing synthesis gas inlet 23 is divided into two paths: one path is connected to the ammonia-containing hydrogen cyanide synthesis gas inlet valve c25, and the other path is connected to the condenser 26 at the top of the decyanation tower through the outlet valve b22.

[0054] The top condenser 26 of the decyanation tower is equipped with a circulating water inlet valve b27 and a circulating water outlet valve a28 on both sides.

[0055] The bottom outlet of the ammonia absorption tower 1 is divided into two paths. One path is connected to the ammonia absorption tower cooler 6 and the pipeline is connected to the ammonia absorption liquid inlet valve 8. The other path is connected to the spray plate b34 in the middle of the decyanation tower 2 via the ammonia absorption tower bottom pump 41 and the pipeline is connected to the programmable valve a40 and valve e33.

[0056] The ammonia absorption tower cooler 6 is equipped with a circulating water inlet valve a7 and a circulating water outlet control valve 13. The circulating water temperature introduced into the ammonia absorption tower cooler 6 is 10℃-40℃.

[0057] The pH online analyzer a39 is associated with the programmable valve a40 on the outlet pipeline of the ammonia absorption tower bottom pump 41. The pH online analyzer a39 controls the pH of the ammonia absorption tower bottom liquid, and the pH value of the ammonia absorption tower bottom liquid is 2-7.

[0058] Temperature analyzer a38 is associated with circulating water outlet control valve 13 of ammonia absorption tower cooler 6. The circulating water outlet control valve 13 automatically opens or closes according to the temperature of temperature analyzer a38 to control the bottom temperature of ammonia absorption tower 1 to 5℃-55℃.

[0059] The ammonia absorption tower 1 contains ammonia absorption liquid, specifically composed of 10%-40% monoammonium phosphate and 0-30% diammonium phosphate. The operating pressure of the ammonia absorption tower 1 is less than -0.05 MPa.

[0060] Spray disc a19 has fixed nozzles a18 evenly distributed, and valve a15 is connected to the deammoniation synthesis gas outlet 16.

[0061] The interior of the decyanation tower 2 is arranged from top to bottom as follows: wire mesh demister b31, Pall ring packing d32, spray plate b34, water distribution pipe b35, and structured packing b37. The cyanide-containing vapor is discharged through the cyanide-containing vapor outlet 30 at the top of the decyanation tower 2.

[0062] The steam inlet of the reboiler 51 in the decyanation tower is associated with the programmable valve b50, which is associated with the temperature analyzer b48. A condensate valve a49 is installed at the bottom of the reboiler 51 in the decyanation tower. The temperature analyzer b48 is connected to the side wall of the bottom of the decyanation tower 2 and is used to detect the temperature of the liquid in the bottom of the decyanation tower 2 and adjust the temperature of the bottom of the decyanation tower 2 to 50℃-150℃.

[0063] The reboiler 51 in the decyanation tower uses a steam heat source with a temperature of 120℃-160℃. The Pall ring packing d32 is made of 316L stainless steel, with two rows of staggered windows on the ring wall. Each row has five tongues, each pointing towards the ring center. The structured packing b37 is also made of 316L stainless steel and is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 30°.

[0064] Atomizing fixed nozzles b36 are evenly distributed on the spray plate b34, and a valve d29 is connected to the cyanide vapor outlet 30 at the top of the decyanation tower 2;

[0065] The cyanide vapor outlet 30 is connected to the inlet of the cyanide removal tower top condenser 26. The shell side of the cyanide removal tower top condenser 26 conveys cyanide vapor, and the tube side conveys circulating water. The temperature of the circulating water used in the cyanide removal tower top condenser 26 is 10℃-40℃.

[0066] The spray plate b34 pipeline connects to two inlet pipelines. One inlet pipeline is connected to the outlet of the ammonia absorption tower bottom pump 41 via valve e33, and the other inlet pipeline is connected to the outlet of the decyanation tower bottom reboiler 51 via the decyanation tower bottom circulation pump 42.

[0067] The inlet pipeline of the decyanation tower bottom circulation pump 42 is equipped with a decyanation tower circulation pump inlet valve 43, and the outlet pipeline is equipped with a decyanation tower circulation pump outlet valve 47.

[0068] The operating pressure at the top of the decyanation tower 2 is greater than -0.05 MPa.

[0069] The interior of the ammonia removal tower 3 is arranged from top to bottom as follows: wire mesh demister c70, spray plate d69, water distribution pipe d67, structured packing d66, spray plate c62, water distribution pipe c63, and structured packing c64. The lower side wall of the ammonia removal tower 3 is equipped with an online pH analyzer b58.

[0070] Structured packing d66 is made of 316L stainless steel. It is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugated angle is 45°; the structured packing C64 is made of 316L stainless steel and is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 30°.

[0071] Ammonia vapor outlet 71 is connected to valve g72, valve g72 is connected to the inlet of the top condenser 73 of the ammonia removal tower, circulating water with a temperature of 10℃-40℃ is introduced into the top condenser 73 of the ammonia removal tower, the outlet of the top condenser 73 of the ammonia removal tower is connected to the inlet of the ammonia water buffer tank 4, and circulating water inlet valve c74 and circulating water outlet valve b75 are respectively installed on both sides of the top condenser 73 of the ammonia removal tower;

[0072] The outlet of the top condenser 73 of the deammoniation tower is connected to the inlet 77 of the ammonia buffer tank 4, and the pipeline is equipped with the outlet valve 76 of the top condenser of the deammoniation tower.

[0073] Atomizing fixed nozzles c65 are evenly distributed on the spray plate c62. The inlet pipeline of the spray plate c62 is divided into two paths. One path is connected to valve f61 and the outlet of the decyanation tower bottom pump 45 in sequence. The other path is connected to the outlet of the deammoniation tower bottom reboiler 59.

[0074] The reboiler 59 of the deammoniation tower is equipped with a programmable valve c60 at its steam inlet, and a condensate valve b57 is installed at the bottom of the reboiler 59. The steam temperature of the reboiler 59 is 150℃-230℃. The steam inlet of the reboiler 59 is associated with the programmable valve c60, which is also associated with the online pH analyzer b58. The programmable valve c60 controls the bottom liquid temperature of the deammoniation tower 3 to be 130℃-180℃, and the pressure of the deammoniation tower is an autogenous pressure of 0.8MPa-1.5MPa.

[0075] Atomizing fixed nozzles d68 are evenly distributed on the spray plate d69, and the spray plate d69 is connected to the outlet of the ammonia water circulation pump 78.

[0076] The bottom output of ammonia absorption tower 1 is divided into two paths. One path is connected to the circulating pump 10 at the bottom of the ammonia absorption tower and passes through the cooler 6 of the ammonia absorption tower to the spray plate a19. The other path is connected to the bottom pump 41 at the bottom of the ammonia absorption tower and passes through the spray plate b34 in the middle of the decyanation tower 2.

[0077] The bottom output of the decyanation tower 2 is divided into two paths. One path is connected to the decyanation tower bottom circulation pump 42, which passes through the decyanation tower bottom reboiler 51 to the spray plate b34. The other path is connected to the decyanation tower bottom outlet pump 45 to the spray plate c62 in the middle of the deammonia removal tower 3.

[0078] The bottom output of the ammonia stripping tower 3 is divided into two paths. One path is connected to the ammonia stripping tower bottom circulation pump 52, which passes through the ammonia stripping tower bottom reboiler 59 to the spray plate c62. The other path is connected to the ammonia stripping tower bottom outlet pump 55, which passes through the ammonia stripping tower bottom cooler 88 to the outlet pipeline of the ammonia absorption tower bottom circulation pump 10.

[0079] An ammonia absorption tower circulating pump 10 is equipped with an ammonia absorption tower circulating pump outlet valve 9 on its outlet pipeline and an ammonia absorption tower circulating pump inlet valve 11 on its inlet pipeline. An ammonia absorption tower bottom-out pump 41 is equipped with an ammonia absorption tower outlet pump inlet valve 12 on its inlet pipeline.

[0080] The inlet pipeline of the decyanation tower bottom pump 45 is equipped with a decyanation tower bottom pump inlet valve 44, and the outlet pipeline is equipped with a decyanation tower bottom pump outlet valve 46.

[0081] The inlet pipeline of the deammoniation tower bottom circulation pump 52 is equipped with an inlet valve 53, and the outlet pipeline is equipped with an outlet valve 56.

[0082] An inlet valve 54 for the deammoniation tower bottom pump 55 is installed on the inlet pipeline, and an outlet valve 89 for the deammoniation tower bottom pump 55 is installed on the outlet pipeline.

[0083] The ammonia removal tower bottom cooler 88 is supplied with circulating water at a temperature of 10℃-40℃ to cool the ammonia absorption liquid that has regained its ammonia absorption capacity. The top of the ammonia removal tower bottom cooler 88 is equipped with an outlet 92, which is connected to the ammonia absorption liquid inlet valve 8. The upper part of the ammonia removal tower bottom cooler 88 is equipped with a programmable control valve e91, and the lower part is equipped with a condensate valve c90.

[0084] The bottom of the ammonia buffer tank 4 is equipped with an ammonia circulation outlet 80 and an ammonia collection outlet 81. The ammonia circulation outlet 80 is connected to the inlet of the ammonia circulation pump 78 to transport low-concentration ammonia back to the spray plate d69. The inlet of the ammonia circulation pump 78 is equipped with an ammonia removal tower ammonia circulation pump inlet valve 79. The ammonia collection outlet 81 is connected to the inlet of the ammonia collection pump 85. The inlet of the ammonia collection pump 85 is equipped with an ammonia removal tower ammonia collection pump inlet valve 84.

[0085] The ammonia storage tank 5 is equipped with a concentrated ammonia inlet 87, which is connected to the outlet of the ammonia extraction pump 85. A programmable valve d83 is installed on the pipeline, which is connected to the concentrated ammonia inlet 87 and the ammonia extraction pump 85.

[0086] The ammonia buffer tank 4 is equipped with an online ammonia analyzer 82, which is associated with a programmable valve d83.

[0087] The ammonia water outlet 81 is connected to the ammonia water extraction pump 85 to transport high-concentration ammonia water to the ammonia water storage tank 5.

[0088] Working principle of this utility model device:

[0089] Hydrogen cyanide synthesis gas with an ammonia concentration of 3%-8% enters the ammonia-containing synthesis gas inlet 23 through valve C25. Under negative pressure, the ammonia-containing hydrogen cyanide synthesis gas rises. The ammonia absorbent liquid in ammonia absorption tower 1 is transported to the ammonia absorption tower cooler 6 by the ammonia absorption tower bottom circulation pump 10 to cool the ammonia absorbent liquid. The cooled ammonia absorbent liquid is then transported to the spray plate A19. The atomizing fixed nozzles on the spray plate A19 disperse the ammonia absorbent liquid onto the water distribution pipe A20. The water distribution pipe A20 further disperses the ammonia absorbent liquid. The dispersed ammonia absorbent liquid and the ammonia-containing hydrogen cyanide synthesis gas react in a gas-liquid reaction on the Pall ring packing C21 and Pall ring packing B14. In the two-phase counter-current contact, the ammonia content in the ammonia-containing hydrogen cyanide synthesis gas decreases, the ammonia absorption liquid's ammonia absorption capacity gradually weakens, and the pH value of the ammonia absorption liquid gradually increases. The ammonia absorption liquid falls into the bottom of the ammonia absorption tower 1 after being buffered by the structured packing. At the same time, the ammonia absorption liquid and the ammonia-containing hydrogen cyanide synthesis gas undergo heat transfer, the temperature of the ammonia absorption liquid increases, and the temperature of the hydrogen cyanide synthesis gas decreases. Some of the water in the hydrogen cyanide synthesis gas is condensed. The ammonia absorption liquid is then transported back to the ammonia absorption tower cooler 6 for cooling using the ammonia absorption tower bottom circulation pump 10, and continues to absorb ammonia. The hydrogen cyanide synthesis gas with ammonia removed is discharged from the valve a15 connected to the ammonia-removed synthesis gas outlet 16.

[0090] After the pH value of the ammonia absorption tower bottom liquid in the ammonia absorption tower 1 is detected to be increased by the online pH analyzer a39, the programmable valve a40 is opened. The ammonia absorption liquid that has lost its ammonia absorption capacity is transported to the spray plate b34 of the decyanation tower 2 by the ammonia absorption tower bottom pump 41. The ammonia absorption liquid containing hydrogen cyanide is transported to the decyanation tower bottom reboiler 51 for heating by the decyanation tower bottom circulation pump 42. The heated ammonia absorption liquid is transported to the spray plate b34. The atomizing fixed nozzle b36 on the spray plate b34 disperses the heated ammonia absorption liquid to the water distribution pipe b35. The water distribution pipe b35 further disperses the ammonia absorption liquid. The ammonia absorption liquid volatilizes cyanide vapor. The cyanide vapor is discharged to the top condenser 26 of the decyanation tower through the cyanide vapor outlet 30 for cooling. The cooled cyanide vapor is transported into the ammonia synthesis gas inlet 23 by the valve b22. The programmable valve b50 controls the valve opening by analyzing the results online by the temperature analyzer b48, thereby controlling the bottom temperature of the decyanation tower 2.

[0091] After the removal of hydrogen cyanide, the ammonia absorbent is pumped from the bottom of the decyanation tower to the spray plate c62 in the deammoniation tower 3 via the bottom pump 45. The spray plate c62 then pumps the ammonia absorbent, which has lost its ammonia absorption capacity, back to the bottom of the deammoniation tower 3. The ammonia absorbent, now deprived of its ammonia absorption capacity, is then pumped from the bottom of the deammoniation tower to the reboiler 59 via the bottom circulation pump 52 for heating. The heated ammonia absorbent is then pumped back to the spray plate c62, where atomizing nozzles c65 disperse the ammonia absorbent. The ammonia absorbent is further dispersed on the water distribution pipe c63 and evenly distributed on the structured packing c64. The heated ammonia absorbent releases ammonia vapor on the structured packing, which is discharged through the ammonia vapor outlet 71 to the top condenser 73 of the deammoniation tower, where it is condensed into low-concentration ammonia water. This low-concentration ammonia water is then discharged into the ammonia water buffer tank 4. The low-concentration ammonia water in the buffer tank 4 is then pumped back to the bottom of the ammonia tower via the ammonia water circulation pump 78. The ammonia solution is sent to the spray plate d69 at the top of the deammoniation tower 3. The atomizing fixed nozzles d68 on the spray plate d69 disperse the low-concentration ammonia solution to the water distribution pipe d67 for further dispersion. The low-concentration ammonia solution and ammonia-containing vapor undergo gas-liquid two-phase counter-current contact on the structured packing d66, resulting in a mass and heat transfer process. The high-concentration ammonia-containing vapor is condensed into high-concentration ammonia solution by the condenser 73 at the top of the deammoniation tower. After the ammonia solution concentration is detected by the online ammonia analyzer 82 at the bottom of the ammonia solution buffer tank 4 as being higher than 10%, the programmable valve d83 is opened to deliver the high-concentration ammonia solution to the ammonia solution storage tank 5. The ammonia absorption liquid, after ammonia removal and restoration of ammonia absorption capacity, is transported to the deammoniation tower bottom cooler 88 for cooling using the deammoniation tower bottom pump 55. After cooling, it is transported to the outlet pipeline of the ammonia absorption tower bottom circulation pump 10 and enters the ammonia absorption tower 1 to circulate and absorb ammonia from the hydrogen cyanide synthesis gas, resulting in ammonia-free hydrogen cyanide synthesis gas.

[0092] To make the objectives, technical solutions, and advantages of this utility model clearer, a detailed description will be provided in conjunction with preferred embodiments of this utility model.

[0093] Example 1

[0094] A method and apparatus for the cyclic absorption of ammonia in hydrogen cyanide includes an ammonia absorption tower 1, a decyanation tower 2, a deammoniation tower 3, an ammonia water buffer tank 4, and an ammonia water storage tank 5 connected in sequence. The ammonia absorption tower 1 has a deammoniation synthesis gas outlet 16 at the top and an ammonia-containing synthesis gas inlet 23 in the middle. The bottom output of the ammonia absorption tower 1 is divided into two paths: one path is sequentially connected to the ammonia absorption tower bottom circulation pump 10 and the ammonia absorption tower cooler 6, and circulated to the top of the ammonia absorption tower 1; the other path is connected to the ammonia absorption tower bottom outlet pump 41. The decyanation tower 2 has a cyanide vapor outlet 30 at the top, which is connected to the inlet of the decyanation tower top condenser 26. The bottom output is divided into two paths. One path is sequentially connected to the decyanation tower bottom circulation pump 42 and the decyanation tower bottom reboiler 51 and circulated to the middle of the decyanation tower 2. The other path is connected to the decyanation tower bottom outlet pump 45. The top of the deammonia tower 3 is provided with an ammonia vapor outlet 71. The ammonia vapor outlet 71 is sequentially connected to the deammonia tower top condenser 73, the ammonia water buffer tank 4, and the ammonia water storage tank 5. The bottom output of the deammonia tower 3 is divided into two paths. One path is sequentially connected to the deammonia tower bottom circulation pump 52 and the deammonia tower bottom reboiler 59 and circulated to the middle of the deammonia tower 3. The other path is sequentially connected to the deammonia tower bottom outlet pump 55 and the deammonia tower bottom cooler 88.

[0095] Example 2

[0096] Devices for the recycling and absorption of ammonia in hydrogen cyanide, such as... Figure 1 As shown, it includes an ammonia absorption tower 1, an ammonia absorption tower bottom circulation pump 10, an ammonia absorption tower cooler 6, an ammonia absorption tower bottom outlet pump 41, a cyanide removal tower 2, a cyanide removal tower bottom reboiler 51, a cyanide removal tower top condenser 26, a cyanide removal tower bottom circulation pump 42, a cyanide removal tower bottom outlet pump 45, an ammonia removal tower 3, a cyanide removal tower bottom reboiler 59, a cyanide removal tower bottom cooler 88, a cyanide removal tower top condenser 73, a cyanide removal tower bottom circulation pump 52, a cyanide removal tower bottom outlet pump 55, an ammonia water buffer tank 4, an ammonia water circulation pump 78, an ammonia water outlet pump 85, and an ammonia water storage tank 5.

[0097] The ammonia absorption tower 1 is equipped with an ammonia removal synthesis gas outlet 16 at the top, a wire mesh demister a17, a spray plate a19, and a water distribution pipe a20 at the top, a Pall ring packing c21, a Pall ring packing b14 and an ammonia-containing synthesis gas inlet 23 at the middle, and a structured packing a24, a temperature analyzer a38 and an online pH analyzer a39 at the bottom.

[0098] Pall ring packing C21 and Pall ring packing B14 are located above the ammonia-containing synthesis gas inlet 23. The two pipelines of the ammonia-containing synthesis gas inlet 23 are connected to valves B22 and C25, respectively.

[0099] Both Pall ring packing C21 and B14 are made of 316L stainless steel. Both Pall ring packing C21 and B14 have a diameter of 25 mm × H25 mm × 0.5 mm. The Pall ring packing ring wall has two rows of windows, which are staggered. Each row of windows has five tongues, each pointing towards the center of the ring. The area of ​​the windows occupies 35% of the ring wall.

[0100] The ammonia absorption tower cooler 6 is located outside the ammonia absorption tower 1. The ammonia absorption tower cooler 6 is used to reduce the temperature of the ammonia absorption liquid to ensure the effectiveness of absorbing ammonia from the hydrogen cyanide synthesis gas. Fresh ammonia absorption liquid is supplied to the ammonia absorption tower 1 from the lower pipeline of the ammonia absorption tower cooler 6.

[0101] The ammonia absorbent is distributed in the spray plate a19, and the atomizing fixed nozzle a18 disperses the ammonia absorbent through the water distribution pipe a20. The water distribution pipe a20 further disperses the ammonia absorbent. The Pall ring packing c21 and Pall ring packing b14 uniformly disperse the ammonia absorbent through the water distribution pipe a20. The gas and liquid are in reverse phase contact to absorb ammonia in the hydrogen cyanide synthesis gas.

[0102] The circulating water outlet control valve 13 is associated with the temperature analyzer a38, which automatically detects the temperature of the liquid in the bottom of the ammonia absorption tower 1.

[0103] The programmable valve a40 is associated with the online pH analyzer a39, which automatically detects the pH value of the bottom liquid in ammonia absorption tower 1;

[0104] The ammonia-containing synthesis gas inlet 23 is connected to two pipelines. One pipeline is the inlet pipeline for recovering hydrogen cyanide after the cyanide-containing vapor discharged from the top of the decyanation tower 2 is cooled by the top condenser 26 of the decyanation tower. The other pipeline is the inlet pipeline for the ammonia-containing hydrogen cyanide synthesis gas after the pyrolysis of formamide.

[0105] The top of the decyanation tower 2 is equipped with a cyanide vapor outlet 30, the upper part is equipped with a wire mesh demister b31 and Pall ring packing d32, the middle part is equipped with a spray plate b34, a water distribution pipe b35 and structured packing b37, and the lower part is equipped with a temperature analyzer b48.

[0106] The bottom output of the decyanation tower 2 is divided into two paths. One path is connected to the decyanation tower bottom circulation pump 42, which heats the bottom liquid of the decyanation tower 2 via the decyanation tower bottom reboiler 51. The hydrogen cyanide and a small amount of water in the bottom liquid of the decyanation tower 2 evaporate into gaseous state and undergo gas-liquid mass transfer through the Pall ring packing d32. The light component medium is discharged from the cyanide vapor outlet 30 and, after condensation, is transported to the ammonia-containing synthesis gas inlet 23. The other path uses the decyanation tower bottom pump 45 to transport the decyanated ammonia absorption liquid to the spray plate c62 in the middle of the decyanation tower 3, where the ammonia absorption liquid restores its ammonia absorption capacity.

[0107] The programmable valve b50 is associated with the temperature analyzer b48. The temperature analyzer b48 automatically detects the temperature of the liquid in the bottom of the decyanation tower 2 and automatically controls the programmable valve b50 at the steam inlet of the reboiler 51 in the bottom of the decyanation tower.

[0108] The Pall ring packing d32 is made of 316L stainless steel, and its dimensions are Φ25 mm × H25 mm × 0.5 mm.

[0109] The reboiler 51 of the decyanation tower is located outside the decyanation tower 2. The reboiler 51 heats the ammonia absorption liquid containing cyanide, so that the hydrogen cyanide in the ammonia absorption liquid is heated into a gaseous state, and the hydrogen cyanide in the ammonia absorption liquid is recovered.

[0110] The ammonia absorbent containing cyanide is distributed in the spray plate b34. The atomizing fixed nozzle b36 disperses the ammonia absorbent containing cyanide in the water distribution pipe b35. The water distribution pipe b35 further disperses the ammonia absorbent containing cyanide. The structured packing b37 evenly disperses the ammonia absorbent containing cyanide on the water distribution pipe b35. The gas and liquid come into counter-phase contact, and the hydrogen cyanide with a lower boiling point volatilizes into other substances and is discharged from the cyanide vapor outlet 30.

[0111] The spray plate b34 pipeline connects to two inlet pipelines. One inlet pipeline is connected to the outlet of the ammonia absorption tower bottom pump 41, which transports the ammonia absorption liquid that has lost its ammonia absorption capacity to the decyanation tower 2 for decyanation treatment and regeneration. The other inlet pipeline is connected to the outlet of the decyanation tower bottom circulation pump 42, which heats the cyanide-containing ammonia absorption liquid through the decyanation tower bottom reboiler 51, volatilizing hydrogen cyanide for recovery.

[0112] Temperature analyzer b48 is connected to the side wall of the bottom of the decyanation tower 2 to monitor the temperature of the liquid in the bottom of the decyanation tower 2 online and control the opening degree of the steam inlet programmable valve b50 of the reboiler 51 in the bottom of the decyanation tower.

[0113] The top of the ammonia removal tower 3 is equipped with an ammonia vapor outlet 71. From top to bottom, a wire mesh demister c70, a spray plate d69, a water distribution pipe d67, and a structured packing d66 are arranged in sequence. The middle part is equipped with a spray plate c62, a water distribution pipe c63, and a structured packing c64. The bottom part is equipped with an online pH analyzer b58.

[0114] The bottom output of the ammonia stripping tower 3 is divided into two paths. One path is connected to the ammonia stripping tower bottom circulation pump 52 to transport ammonia absorption liquid to the ammonia stripping tower bottom reboiler 59. The ammonia stripping tower bottom reboiler 59 heats the ammonia absorption liquid, and the ammonia absorption liquid decomposes under heat to release ammonia and water. The other path is connected to the ammonia stripping tower bottom outlet pump 55. After the ammonia stripping tower bottom cooler 88 cools the ammonia absorption liquid, it is transported to the ammonia absorption tower circulation pump outlet pipeline of ammonia absorption tower 1.

[0115] The ammonia absorbent is distributed in the spray plate c62. The atomizing fixed nozzle c65 disperses the ammonia absorbent on the water distribution pipe c63. The water distribution pipe c63 disperses the heated ammonia absorbent on the structured packing c64. The structured packing c64 evenly disperses the ammonia absorbent on the water distribution pipe c63. The ammonia in the ammonia absorbent is fully volatilized and discharged from the ammonia vapor outlet 71.

[0116] The programmable valve C60 is associated with the pH online analyzer B58. The pH online analyzer B58 automatically detects the pH value of the liquid in the bottom of the deammoniation tower 3 and automatically controls the programmable valve C60 at the steam inlet of the reboiler 59 in the bottom of the deammoniation tower.

[0117] The reboiler 59 at the bottom of the ammonia removal tower is located outside the ammonia removal tower 3. The reboiler 59 heats the ammonia absorption liquid, causing the medium in the ammonia absorption liquid to decompose and release ammonia, thus recovering the ammonia in the ammonia absorption liquid.

[0118] The spray plate C62 pipeline connects to two inlet pipelines. One inlet pipeline is connected to the outlet of the decyanation tower bottom pump 45, which transports the ammonia absorption liquid after removing hydrogen cyanide to the deammoniation tower 3 for deammoniation treatment. The other inlet pipeline is connected to the outlet of the deammoniation tower bottom circulation pump 52, which heats the ammonia absorption liquid through the deammoniation tower bottom reboiler 59, decomposing ammonia for recovery.

[0119] The pH online analyzer b58 is connected to the side wall of the bottom of the deammoniation tower 3 to detect the pH value of the bottom liquid of the deammoniation tower 3 online and control the opening degree of the steam inlet programmable valve c60 of the reboiler 59 of the deammoniation tower.

[0120] The top condenser 73 of the ammonia removal tower condenses ammonia vapor into liquid, and the ammonia water buffer tank 4 stores low-concentration ammonia water.

[0121] The ammonia buffer tank 4 uses an ammonia circulating pump 78 to deliver low-concentration ammonia to the spray plate d69. The atomizing fixed nozzle d68 disperses the low-concentration ammonia through the water distribution pipe d67. The water distribution pipe d67 further disperses the low-concentration ammonia. The structured packing d66 passes through the water distribution pipe d67 and uniformly disperses the low-concentration ammonia, achieving gas-liquid counter-phase contact to achieve the purpose of two-phase mass transfer.

[0122] An online ammonia analyzer 82 is installed on the lower side wall of the ammonia buffer tank 4. When the ammonia concentration in the ammonia buffer tank 4 rises to 10%, the programmable valve d83 is automatically opened, and the ammonia extraction pump 85 is used to transport high-concentration ammonia to the ammonia storage tank 5.

[0123] In this invention, the ammonia content in the hydrogen cyanide synthesis gas is 3%-8%, and the remaining gases are hydrogen cyanide, water, and carbon monoxide. A 10%-50% ammonium phosphate solution is used as the ammonia absorbent to absorb the ammonia in the hydrogen cyanide synthesis gas. The temperature of the ammonia absorption tower is controlled to promote the absorption effect of ammonia in the hydrogen cyanide synthesis gas and to remove some water from the hydrogen cyanide synthesis gas in the condensation section. After the ammonia absorbent loses its ammonia absorption capacity, it undergoes ammonia removal treatment after removing hydrogen cyanide. The ammonia absorbent, which has regained its ammonia absorption capacity, is then transported back to the ammonia absorption tower for ammonia absorption, thereby obtaining ammonia-free hydrogen cyanide synthesis gas. Further processing yields high-purity hydrogen cyanide and high-concentration ammonia water.

[0124] Example 3: 208 m³ of ammonia-containing syngas with an original ammonia content of 6.11%. 3 The pH value of ammonia absorption tower 1 was controlled at 5.41, monoammonium phosphate at 11.99%, diammonium phosphate at 6.06%, and the temperature at 32.1℃. The circulation rate of the bottom liquid of ammonia absorption tower 1 was 1000 L / h. Ammonia was not detected in the synthesis gas.

[0125] Example 4: 221 m³ of ammonia-containing syngas with an original ammonia content of 6.49% 3 The pH value of ammonia absorption tower 1 was controlled at 5.03, monoammonium phosphate at 12.97%, diammonium phosphate at 3.25%, and the temperature at 33.5℃. The circulation rate of the bottom liquid of ammonia absorption tower 1 was 1000 L / h. Ammonia was not detected in the synthesis gas.

[0126] Example 5: 197 m³ of ammonia-containing syngas with an original ammonia content of 5.33%. 3 The pH value of ammonia absorption tower 1 was controlled at 4.36, monoammonium phosphate at 13.18%, diammonium phosphate at 3.39%, and the temperature at 27.1℃. The circulation rate of the bottom liquid of ammonia absorption tower 1 was 1000 L / h. Ammonia was not detected in the synthesis gas.

[0127] Example 6: 241 m³ of ammonia-containing syngas with an original ammonia content of 6.49% 3 The pH value of ammonia absorption tower 1 was controlled at 4.31, monoammonium phosphate at 13.65%, diammonium phosphate at 5.33%, and the temperature at 30.5℃. The circulation rate of the bottom liquid of ammonia absorption tower 1 was 1000 L / h. Ammonia was not detected in the synthesis gas.

Claims

1. Apparatus for the cyclic absorption of ammonia in hydrocyanic acid, characterized in that, The system includes an ammonia absorption tower (1), a cyanide removal tower (2), an ammonia removal tower (3), an ammonia water buffer tank (4), and an ammonia water storage tank (5) connected in sequence. The ammonia absorption tower (1) has a cyanide removal synthesis gas outlet (16) at the top and an ammonia-containing synthesis gas inlet (23) in the middle. The bottom output of the ammonia absorption tower (1) is divided into two paths. One path is sequentially connected to the ammonia absorption tower bottom circulation pump (10) and the ammonia absorption tower cooler (6) and circulated to the top of the ammonia absorption tower (1). The other path is connected to the ammonia absorption tower bottom outlet pump (41). The cyanide removal tower (2) has a cyanide vapor outlet (30) at the top, which is connected to the inlet of the cyanide removal tower top condenser (26). The bottom output of the cyanide removal tower (2) is divided into two paths. There are two paths. One path is connected in sequence to the decyanation tower bottom circulation pump (42) and the decyanation tower bottom reboiler (51) and circulates to the middle of the decyanation tower (2). The other path is connected to the decyanation tower bottom outlet pump (45). The top of the deammonia tower (3) is provided with an ammonia vapor outlet (71). The ammonia vapor outlet (71) is connected in sequence to the deammonia tower top condenser (73), the ammonia water buffer tank (4) and the ammonia water storage tank (5). The bottom output of the deammonia tower (3) is divided into two paths. One path is connected in sequence to the deammonia tower bottom circulation pump (52) and the deammonia tower bottom reboiler (59) and circulates to the middle of the deammonia tower (3). The other path is connected in sequence to the deammonia tower bottom outlet pump (55) and the deammonia tower bottom cooler (88).

2. The apparatus for ammonia recycle absorption in hydrocyanation according to claim 1, wherein The ammonia absorption tower (1) is equipped with a wire mesh demister a (17), a spray plate a (19), a water distribution pipe a (20), a Pall ring packing c (21), a Pall ring packing b (14), and a structured packing a (24) from top to bottom. The lower side wall of the ammonia absorption tower (1) is equipped with an online pH analyzer a (39) and a temperature analyzer a (38). The deammoniated syngas is discharged through the deammoniated syngas outlet (16) at the top of the ammonia absorption tower. The ammonia-containing synthesis gas inlet (23) is located between Pall ring packing b (14) and structured packing a (24); The ammonia-containing synthesis gas inlet (23) is divided into two paths: one path is connected to the ammonia-containing hydrogen cyanide synthesis gas inlet valve c (25), and the other path is connected to the decyanation tower top condenser (26) through the outlet valve b (22); The top condenser (26) of the decyanation tower is equipped with a circulating water inlet valve b (27) and a circulating water outlet valve a (28) on both sides. The bottom outlet of the ammonia absorption tower (1) is divided into two paths. One path is connected to the ammonia absorption tower cooler (6) and the pipeline is connected to the ammonia absorption liquid inlet valve (8). The other path is connected to the spray plate b (34) in the middle of the decyanation tower (2) via the ammonia absorption tower bottom pump (41) and the pipeline is connected to the programmable valve a (40) and valve e (33). The ammonia absorption tower cooler (6) is equipped with a circulating water inlet valve a (7) and a circulating water outlet control valve (13), and circulating water is introduced into the ammonia absorption tower cooler (6); The pH online analyzer a (39) is associated with the programmable valve a (40) on the outlet pipeline of the ammonia absorption tower bottom pump (41), and the pH online analyzer a (39) controls the pH of the bottom liquid of the ammonia absorption tower (1); The temperature analyzer a (38) is associated with the circulating water outlet programmable valve (13) of the ammonia absorption tower cooler (6). The circulating water outlet programmable valve (13) automatically opens or closes the valve position of the circulating water outlet programmable valve (13) according to the temperature of the temperature analyzer a (38) to control the temperature of the bottom of the ammonia absorption tower (1).

3. The apparatus for ammonia recycle absorption in hydrocyanation according to claim 2, wherein The spray plate a (19) is uniformly distributed with fixed nozzles a (18), and the deammoniation synthesis gas outlet (16) is connected to a valve a (15).

4. The apparatus for ammonia recycle absorption in hydrocyanation according to claim 3, wherein The decyanation tower (2) is equipped with a wire mesh demister b (31), a Pall ring packing d (32), a spray plate b (34), a water distribution pipe b (35), and a structured packing b (37) from top to bottom. The cyanide-containing vapor is discharged through the cyanide-containing vapor outlet (30) at the top of the decyanation tower (2). The steam inlet of the reboiler (51) of the decyanation tower is associated with the programmable valve b (50), which is associated with the temperature analyzer b (48). A condensate valve a (49) is provided at the bottom of the reboiler (51) of the decyanation tower. The temperature analyzer b (48) is connected to the side wall of the bottom of the decyanation tower (2) and is used to detect the temperature of the liquid in the bottom of the decyanation tower (2) and adjust the temperature of the bottom of the decyanation tower (2). The reboiler (51) of the decyanation tower uses steam as a heat source. The Pall ring packing d (32) has two rows of windows on its ring wall, which are staggered. Each row of windows has five tongues, which point to the center of the ring. The structured packing b (37) is a vertical corrugated packing with a specific surface area of ​​450 m². 2 / m 3 The corrugation angle is 30°.

5. The apparatus for ammonia recycle absorption in hydrocyanation according to claim 4, wherein The spray plate b (34) is uniformly distributed with atomizing fixed nozzles b (36), and the cyanide vapor outlet (30) at the top of the decyanation tower (2) is connected to a valve d (29). The outlet of the cyanide-containing vapor (30) is associated with the inlet of the top condenser (26) of the decyanation tower. The shell side of the top condenser (26) of the decyanation tower carries cyanide-containing vapor, and the tube side carries circulating water. The top condenser (26) of the decyanation tower is circulated with circulating water. The spray plate b (34) is connected to two inlet pipelines. One inlet pipeline is connected to the outlet of the ammonia absorption tower bottom pump (41) via valve e (33), and the other inlet pipeline is connected to the outlet of the decyanation tower bottom reboiler (51) via the decyanation tower bottom circulation pump (42). The inlet pipeline of the decyanation tower bottom circulation pump (42) is equipped with a decyanation tower circulation pump inlet valve (43), and the outlet pipeline is equipped with a decyanation tower circulation pump outlet valve (47).

6. The apparatus for the cyclic absorption of ammonia in hydrogen cyanide according to claim 2, characterized in that, The deammonia removal tower (3) is provided with a wire mesh demister c (70), a spray plate d (69), a water distribution pipe d (67), a structured packing d (66), a spray plate c (62), a water distribution pipe c (63), and a structured packing c (64) from top to bottom. The lower side wall of the deammonia removal tower (3) is provided with an online pH analyzer b (58). The structured packing d (66) is vertical wave packing, specific surface area is 450 m 2 / m 3 , wave inclination 45°; the structured packing c (64) is vertical wave packing, specific surface area is 450 m 2 / m 3 , wave inclination 30°; The ammonia vapor outlet (71) is associated with valve g (72), the valve g (72) is associated with the inlet of the deammoniation tower top condenser (73), the deammoniation tower top condenser (73) is supplied with circulating water, the outlet of the deammoniation tower top condenser (73) is associated with the inlet of the ammonia water buffer tank (4), and circulating water inlet valve c (74) and circulating water outlet valve b (75) are respectively provided on both sides of the deammoniation tower top condenser (73). The outlet of the top condenser (73) of the deammoniation tower is connected to the inlet (77) of the ammonia buffer tank (4), and the pipeline is equipped with the outlet valve (76) of the top condenser of the deammoniation tower.

7. The apparatus for the cyclic absorption of ammonia in hydrogen cyanide according to claim 6, characterized in that, The spray plate c (62) is evenly distributed with atomizing fixed nozzles c (65). The inlet pipeline of the spray plate c (62) is divided into two paths. One path is connected in sequence to the valve f (61) and the outlet of the decyanation tower bottom pump (45). The other path is connected to the outlet of the deammoniation tower bottom reboiler (59). The steam inlet of the reboiler (59) of the deammoniation tower is equipped with a programmable valve c (60), and the lower part of the reboiler (59) of the deammoniation tower is equipped with a condensate valve b (57). The steam inlet of the reboiler (59) of the deammoniation tower is associated with the programmable valve c (60), and the programmable valve c (60) is associated with the pH online analyzer b (58). The programmable valve c (60) controls the temperature of the liquid in the bottom of the deammoniation tower (3). The spray plate d (69) is uniformly distributed with atomizing fixed nozzles d (68), and the spray plate d (69) is associated with the outlet of the ammonia water circulation pump (78).

8. The apparatus for the cyclic absorption of ammonia in hydrogen cyanide according to claim 7, characterized in that, The ammonia absorption tower (1) has two outputs at the bottom. One output is connected to the ammonia absorption tower bottom circulation pump (10), and then to the spray plate a (19) via the ammonia absorption tower cooler (6). The other output is connected to the ammonia absorption tower bottom outlet pump (41) and then to the spray plate b (34) in the middle of the decyanation tower (2). The bottom output of the decyanation tower (2) is divided into two paths. One path is connected to the decyanation tower bottom circulation pump (42) and then to the decyanation tower bottom reboiler (51) to the spray plate b (34). The other path is connected to the decyanation tower bottom outlet pump (45) to the spray plate c (62) in the middle of the deammonia removal tower (3). The bottom output of the deammoniation tower (3) is divided into two paths. One path is connected to the deammoniation tower bottom circulation pump (52) and then to the spray plate c (62) via the deammoniation tower bottom reboiler (59). The other path is connected to the deammoniation tower bottom outlet pump (55) and then to the outlet pipeline of the ammonia absorption tower bottom circulation pump (10) via the deammoniation tower bottom cooler (88). An outlet valve (9) for the ammonia absorption tower circulating pump (10) is installed on the outlet pipeline, and an inlet valve (11) for the ammonia absorption tower circulating pump is installed on the inlet pipeline. An inlet valve (12) for the ammonia absorption tower bottom pump (41) is installed on the inlet pipeline. The inlet pipeline of the decyanation tower bottom pump (45) is equipped with a decyanation tower bottom pump inlet valve (44), and the outlet pipeline is equipped with a decyanation tower bottom pump outlet valve (46). The inlet pipeline of the deammoniation tower bottom circulation pump (52) is equipped with an inlet valve (53) and the outlet pipeline is equipped with an outlet valve (56). The inlet pipeline of the deammoniation tower bottom pump (55) is equipped with an inlet valve (54) and the outlet pipeline is equipped with an outlet valve (89).

9. The apparatus for the cyclic absorption of ammonia in hydrogen cyanide according to claim 8, characterized in that, The deammonia removal tower bottom cooler (88) is supplied with circulating water to cool the ammonia absorption liquid that has regained its ammonia absorption capacity. The top of the deammonia removal tower bottom cooler (88) is provided with a deammonia removal tower bottom cooler outlet (92), which is connected to the ammonia absorption liquid inlet valve (8). The upper part of the deammonia removal tower bottom cooler (88) is provided with a programmable valve e (91), and the lower part is provided with a condensate valve c (90).

10. The apparatus for the cyclic absorption of ammonia in hydrogen cyanide according to claim 8, characterized in that, The ammonia buffer tank (4) is provided with an ammonia circulation outlet (80) and an ammonia collection outlet (81) at the bottom. The ammonia circulation outlet (80) is connected to the inlet of the ammonia circulation pump (78) to transport low-concentration ammonia back to the spray plate d (69). The ammonia circulation pump (78) is provided with an ammonia removal tower ammonia circulation pump inlet valve (79). The ammonia collection outlet (81) is connected to the inlet of the ammonia collection pump (85). The ammonia collection pump (85) is provided with an ammonia removal tower ammonia collection pump inlet valve (84). The ammonia storage tank (5) is equipped with a concentrated ammonia inlet (87), which is connected to the outlet of the ammonia extraction pump (85). A programmable valve d (83) is installed on the pipeline. The ammonia buffer tank (4) is equipped with an online ammonia analyzer (82) on its side wall, and the online ammonia analyzer (82) is associated with the programmable valve d (83); The ammonia water outlet (81) is connected to the ammonia water extraction pump (85) to transport high-concentration ammonia water to the ammonia water storage tank (5).

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