A component pretreatment method for hydrocyanic acid synthesis gas

Abstract

The invention relates to the technical field of chemical production, and specifically discloses a component pretreatment method for hydrogen cyanide synthesis gas. The method comprises the following steps: step S1: introducing a diammonium phosphate solution into an ammonia removal device and starting the ammonia removal device; step S2: introducing hydrogen cyanide synthesis gas containing ammonia into the ammonia removal device, causing the ammonia to react with the diammonium phosphate solution to generate diammonium phosphate, which is retained in the ammonia removal device, and the hydrogen cyanide synthesis gas to be directly discharged from the ammonia removal device; and step S3: thermally decomposing the retained diammonium phosphate solution in the ammonia removal device to generate ammonia and a diammonium phosphate solution, discharging the ammonia separately, and refluxing the diammonium phosphate solution into the ammonia removal device to reabsorb the hydrogen cyanide synthesis gas containing ammonia. The method solves the problem in a traditional hydrogen cyanide preparation process that, during absorption treatment of ammonia in the hydrogen cyanide synthesis gas, complexes generated are accumulated at the bottom of an ammonia absorption tower, and the complexes entrained in the solution discharge process affect the discharge of liquid and the discharge of ammonia from the solution.

Description

Technical Field

[0001] The present application relates to the technical field of chemical production, and specifically discloses a component pretreatment method for hydrocyanic acid synthesis gas. Background Art

[0002] Hydrocyanic acid, a basic chemical raw material with a wide range of applications, can be used in the manufacture of acrylonitrile, acrylic resins, and pesticides. Hydrocyanic acid, also known as hydrogen cyanide (HCN), is a colorless solution that can be industrially produced by reacting ammonia with natural gas and oxygen-containing gases in the presence of a suitable catalyst at high temperatures in a converter.

[0003] During the production of hydrocyanic acid, the discharged synthesis gas will include unreacted ammonia and product hydrocyanic acid. Ammonia will polymerize with hydrocyanic acid to produce black polymers, which can cause blockage of equipment pipelines and even explosions in severe cases. Therefore, before absorbing hydrocyanic acid into liquid phase, it is necessary to remove the ammonia component contained in the synthesis gas, which is also a pretreatment step for the ammonia-containing gas.

[0004] In the prior art, since both hydrocyanic acid and ammonia are easily soluble in water, the insolubility of hydrocyanic acid in acidic solutions is often utilized to pass the synthesis gas into an ammonia removal tower sprayed with an acidic solution to remove the ammonia. In the ammonia removal tower, the hydrocyanic acid synthesis gas flows from bottom to top, and the acidic solution is sprayed from top to bottom and contacts the hydrocyanic acid synthesis gas to react with the ammonia, thereby achieving the purpose of absorbing the ammonia. The hydrocyanic acid synthesis gas that does not contain ammonia and has been pretreated is discharged from the top of the tower.

[0005] In the prior art, there are methods for absorbing ammonia using sulfuric acid and ammonium phosphate solutions. However, the ammonium sulfate generated by the sulfuric acid solution after absorbing ammonia requires multiple processing steps before the absorbed ammonia can be discharged. In contrast, the ammonium phosphate solution absorbed by the ammonium phosphate solution is sprayed with an ammonium dihydrogen phosphate solution, which generates a diammonium hydrogen phosphate solution after absorbing ammonia. At high temperatures of 373°K-393°K, the diammonium hydrogen phosphate solution can release ammonia and be reduced to an ammonium dihydrogen phosphate solution, which can be reused.

[0006] For ammonia absorption towers that use ammonium phosphate solution to absorb ammonia, complexes are formed in the solution during the process of absorbing ammonia and introducing synthesis gas. The complexes float in the liquid or accumulate at the bottom nozzle of the ammonia absorption tower. As the diammonium phosphate solution is continuously sprayed, the liquid level in the sedimentation tank at the bottom of the ammonia absorption tower continues to rise. Therefore, it is necessary to regularly discharge the diammonium phosphate solution and then reduce it in a reduction tower to separate the ammonia, obtaining the diammonium phosphate solution for recycling. However, due to the presence of complexes in the solution, when the diammonium phosphate solution is discharged from the sedimentation tank, the complexes also enter the reduction tower. The continued accumulation of complexes will cause blockage of the inner wall of the solution circulation pipe.

[0007] Therefore, in view of this, the inventors provide a component pretreatment method for hydrocyanic acid synthesis gas to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the problem in the traditional hydrogen cyanide preparation process that during the absorption treatment of ammonia in the discharged hydrogen cyanide synthesis gas, the complex generated will accumulate at the bottom of the ammonia absorption tower, and the complex entrained in the process of discharging the solution will affect the discharge of liquid and the discharge of ammonia from the solution.

[0009] In order to achieve the above object, the basic solution of the present invention provides a component pretreatment method for hydrocyanic acid synthesis gas, step S1: introducing ammonium dihydrogen phosphate solution into an ammonia removal device and starting the ammonia removal device;

[0010] Step S2: introducing hydrogen cyanide synthesis gas containing ammonia into the ammonia removal equipment, where the ammonia reacts with the ammonium dihydrogen phosphate solution to produce diammonium hydrogen phosphate, which is retained in the ammonia removal equipment. The hydrogen cyanide synthesis gas is directly discharged from the ammonia removal equipment.

[0011] Step S3: The remaining diammonium hydrogen phosphate solution is thermally decomposed into ammonia gas and diammonium dihydrogen phosphate solution through the ammonia removal equipment, the ammonia gas is discharged separately, and the diammonium dihydrogen phosphate solution is refluxed into the ammonia removal equipment to reabsorb the hydrogen cyanide synthesis gas containing ammonia gas.

[0012] Furthermore, the ammonia removal equipment includes a reaction box for containing diammonium hydrogen phosphate solution and an exhaust assembly installed in the reaction box, and one side of the reaction box is connected to an air inlet pipe for unidirectionally introducing ammonia-containing synthesis gas into the diammonium hydrogen phosphate solution;

[0013] The exhaust assembly includes, in sequence along the gas injection direction, a hydrogen cyanide synthesis gas exhaust structure for exhausting hydrogen cyanide synthesis gas and an ammonia independent exhaust structure for pyrolyzing diammonium hydrogen phosphate and independently exhausting ammonia gas;

[0014] The hydrogen cyanide synthesis gas discharge structure includes a clearing rotor arranged obliquely in the reaction box along the gas injection direction, a clearing delivery pipe coaxially arranged inside the clearing rotor, and a clearing rotor shaft coaxially arranged inside the clearing delivery pipe. A scraping structure for cleaning the inner wall of the clearing rotor is fixedly connected to the clearing rotor shaft. A spiral blade that fits the inner wall of the clearing delivery pipe is fixedly connected to the clearing rotor shaft along the axial direction. The clearing delivery pipe is provided with a semicircular groove with the top exposed to the liquid surface. A plurality of inclined through grooves are provided circumferentially between the two ends of the clearing rotor.

[0015] The ammonia independent exhaust structure includes an ammonia pyrolysis structure and an ammonia exhaust structure which are arranged in the reaction box and are sequentially connected. The ammonia pyrolysis structure is also connected to a reflux structure for discharging the diammonium dihydrogen phosphate solution generated by pyrolysis and supplying it into the reaction box.

[0016] The reaction box is provided with an ammonia outlet box body for wrapping the ammonia pyrolysis structure and the inclined through slot on the lower side of the clearing rotor. The reaction box is also fixed with a driving structure for driving the clearing rotor shaft to rotate.

[0017] Furthermore, the reaction box is further provided with a liquid inlet component connected to the air inlet pipe, and the reflux structure is connected to the liquid inlet component and is supplied with diammonium dihydrogen phosphate solution.

[0018] Furthermore, the liquid inlet assembly includes an infusion structure fixedly connected to the reaction box and a liquid inlet box fixedly connected to the reaction box and supplied with liquid by a reflux structure. The infusion structure includes an infusion tube connected to the air inlet pipe, support frames fixedly connected to both ends of the infusion tube, and an infusion mechanism arranged between the support frames at both ends. The infusion tube is provided with a liquid inlet hole for connecting the liquid inlet box and the infusion mechanism.

[0019] Furthermore, the infusion mechanism includes an infusion shaft coaxially rotatably connected between the support frames at both ends and an infusion blade circumferentially fixed to the infusion shaft. A liquid inlet swivel for fixing the outer end of the infusion blade is rotatably connected to the inner side of the infusion tube. An infusion chamber is provided in each of the infusion blades. A connecting ring groove for connecting the infusion chamber and the liquid inlet through hole is provided on the liquid inlet swivel. A plurality of first liquid outlet holes respectively connected to the infusion chamber are provided on the end of the infusion blade facing the air inlet pipe.

[0020] Furthermore, the infusion blades are all uniformly tilted toward one side, and the end surfaces of the infusion blades facing the air inlet pipe are each provided with a plurality of second liquid outlet holes respectively connected to the infusion chambers.

[0021] Furthermore, the reaction box is provided with a spray structure for flushing and clearing the blocked rotor, and a second auxiliary liquid supply pipe is connected between the spray structure and the reflux structure for introducing diammonium dihydrogen phosphate solution.

[0022] Furthermore, the spray structure is arranged above the blockage clearing drum. The spray structure is a spray barrel connected to the second auxiliary liquid supply pipe and covering multiple inclined slots. The spray barrel is provided with a number of spray holes equidistantly corresponding to the inclined slots.

[0023] The principle and effect of this solution are:

[0024] 1. Compared with the prior art, the present invention absorbs ammonia in hydrogen cyanide synthesis gas by using ammonium dihydrogen phosphate solution. The ammonium dihydrogen phosphate solution reacts with ammonia to form diammonium hydrogen phosphate solution. The hydrogen cyanide in the synthesis gas does not react with the acidic ammonium dihydrogen phosphate solution, nor does it dissolve into the acidic ammonium dihydrogen phosphate and the diammonium hydrogen phosphate solution formed by the reaction. Therefore, the ammonia can be effectively removed, and the pretreatment process of the ammonia-containing hydrogen cyanide synthesis gas is completed to meet the requirements of the next step.

[0025] 2. Compared with the prior art, the present invention absorbs ammonia by using ammonium dihydrogen phosphate solution. The generated diammonium hydrogen phosphate can undergo pyrolysis reaction at a suitable temperature to produce ammonia and ammonium dihydrogen phosphate, which can be recycled and reintroduced into the ammonia removal equipment after pyrolysis to reabsorb the hydrogen cyanide synthesis gas containing ammonia.

[0026] 3. Compared with the prior art, the ammonia removal equipment of the present invention uses a reaction box to accommodate the ammonium dihydrogen phosphate solution, and introduces hydrogen cyanide synthesis gas containing ammonia through the air inlet pipe and directly contacts the ammonium dihydrogen phosphate solution. The hydrogen cyanide synthesis gas that is insoluble in the solution is directly discharged and located in the upper cavity of the reaction box, and the ammonia is absorbed by the ammonium dihydrogen phosphate solution to generate diammonium hydrogen phosphate solution. The ammonia pyrolysis structure in the independent ammonia discharge structure pyrolyzes the diammonium hydrogen phosphate solution, and the reflux structure circulates the pyrolyzed diammonium hydrogen phosphate solution into the reaction box. The solution flows in the direction of the current ammonia pyrolysis structure. When the solution flows through the blockage removal rotor, it is filtered through the inclined through-grooves to retain complexes, large particles of debris, etc. in the blockage removal rotor. The impurity-free solution enters the ammonia outlet box, and is driven to rotate by the provided scraping structure. When the debris moves to a high position, it falls into the blockage removal conveying pipe below. The debris falls into the semicircular groove exposed to the liquid surface on the blockage removal conveying pipe and is pushed upward and discharged by the rotating spiral blades for storage. This solves the problem in the traditional hydrogen cyanide preparation process that when the ammonia in the discharged hydrogen cyanide synthesis gas is absorbed, the complexes generated will accumulate at the bottom of the ammonia absorption tower, and the complexes entrained in the solution discharge process will affect the discharge of liquid and the discharge of ammonia from the solution.

[0027] 4. Compared with the prior art, the semicircular groove provided on the clearing and transporting pipe of the present invention has a section exposed above the liquid surface, and the clearing and transporting pipe is connected to the upper cavity of the reaction box. The hydrogen cyanide synthesis gas that has been pretreated for ammonia removal and remains in the upper cavity of the reaction box is discharged through the clearing and transporting pipe.

[0028] 5. Compared with the prior art, the reaction box of the present invention is further provided with a liquid inlet assembly. When the pyrolyzed diammonium phosphate solution is supplied to the reaction box through the reflux structure, the liquid inlet assembly is directly sprayed to the end of the air inlet pipe. The supplied diammonium phosphate solution and the supplied gas are guided through the liquid infusion pipe and their reaction space is limited. In addition, the supplied diammonium phosphate solution can react with ammonia in a timely manner and be discharged into the hydrogen cyanide synthesis gas discharge structure at the rear after the reaction.

[0029] 6. Compared to the prior art, the present invention further incorporates a spray mechanism within the reaction chamber. The spray barrel within the spray mechanism directs the pyrolyzed diammonium phosphate solution into the chamber, which is then sprayed through the inclined slots via the spray holes. When ammonia gas escapes into the upper cavity of the reaction chamber, it passes through a water curtain or spray of diammonium phosphate solution sprayed from the spray holes before being discharged, absorbing the escaped ammonia gas. Furthermore, when the scraping mechanism rotates to the corresponding spray hole position, the sprayed solution cleans the solution and then falls into the delivery pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of an ammonia removal device for a component pretreatment method of hydrocyanic acid synthesis gas proposed in an embodiment of the present application is shown;

[0032] Figure 2 The figure shows an internal schematic diagram of an ammonia removal device applied to a component pretreatment method of hydrocyanic acid synthesis gas proposed in an embodiment of the present application;

[0033] Figure 3 The figure shows an internal schematic diagram of an ammonia removal device applied to a component pretreatment method of hydrocyanic acid synthesis gas proposed in an embodiment of the present application;

[0034] Figure 4 A partial schematic diagram of an ammonia removal device applied to a component pretreatment method of hydrocyanic acid synthesis gas proposed in an embodiment of the present application is shown;

[0035] Figure 5 A partial schematic diagram of an ammonia removal device applied to a component pretreatment method of hydrocyanic acid synthesis gas proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0036] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0037] The figure marks in the drawings of the specification include: liquid inlet box 1, synthesis gas outlet box 2, ammonia outlet box 3, air inlet duct 4, energy supply box 5, exhaust shaft 6, clearing shaft 7, clearing delivery pipe 8, air outlet pipe 9, clearing rotor 10, spray barrel 11, driven swivel 12, liquid infusion pipe 13, liquid inlet box 14, spiral blade 15, discharge pipe 16, synthesis gas discharge pipe 17, liquid inlet pipe 18, driven plate 19, active plate 20, heat conduction plate 21, electric heating rod 22, liquid infusion blade 23, material receiving plate 24, main liquid supply pipe 25.

[0038] A component pretreatment method for hydrocyanic acid synthesis gas, for example Figure 1 As shown:

[0039] The implementation steps include:

[0040] Step S1: introducing ammonium dihydrogen phosphate solution into the ammonia removal equipment and starting the ammonia removal equipment;

[0041] Step S2: introducing hydrogen cyanide synthesis gas containing ammonia into the ammonia removal equipment, where the ammonia reacts with the ammonium dihydrogen phosphate solution to produce diammonium hydrogen phosphate, which is retained in the ammonia removal equipment, and the hydrogen cyanide gas is directly discharged from the ammonia removal equipment;

[0042] Step S3: The remaining diammonium hydrogen phosphate solution is thermally decomposed into ammonia gas and diammonium dihydrogen phosphate solution through the ammonia removal equipment, the ammonia gas is discharged separately, and the diammonium dihydrogen phosphate solution is refluxed into the ammonia removal equipment to reabsorb the hydrogen cyanide synthesis gas containing ammonia gas.

[0043] Among them, the ammonia removal equipment used includes:

[0044] A reaction box and a set of exhaust components installed in the reaction box, the exhaust components include a hydrogen cyanide synthesis gas exhaust structure and an independent ammonia exhaust structure.

[0045] In this example, the reaction box specifically consists of three parts connected in sequence from left to right: a liquid inlet box 1, a synthesis gas outlet box 2, and an ammonia gas outlet box 3. The hydrogen cyanide synthesis gas exhaust structure is installed in the synthesis gas outlet box 2, and the independent ammonia exhaust structure is installed in the ammonia gas outlet box 3. The liquid inlet box 1 is a rectangular box. An air inlet for admitting ammonia-containing synthesis gas is opened at the bottom left side of the liquid inlet box 1. An air inlet pipe connected to the air inlet is installed on the left side of the liquid inlet box 1. A one-way air inlet valve that can only be opened toward the inside of the liquid inlet box 1 is also installed at the air inlet.

[0046] A liquid inlet assembly connected to the air inlet is also installed in the liquid inlet box 1, which is used to introduce the reduced ammonium dihydrogen phosphate solution into the liquid inlet box 1 and allow the ammonium dihydrogen phosphate solution to contact the discharged ammonia-containing synthesis gas to adsorb the ammonia in the ammonia-containing synthesis gas. The liquid inlet assembly includes a liquid inlet box 14 and an infusion structure connected to the liquid inlet box 14 and installed at the air inlet. The liquid inlet box 1 is provided with a liquid inlet connected to the liquid inlet box 14. The infusion structure includes an infusion tube 13 that wraps around the air inlet and is connected to the air inlet pipe, support frames installed at both ends of the infusion tube 13, and an infusion shaft that is coaxial with the infusion tube 13 and rotatably installed between the support frames at both ends. Six infusion blades 23 tilted toward the air inlet are fixedly installed circumferentially on the infusion shaft, and the outer sides of the infusion blades 23 are fixed to an annular liquid inlet swivel. Each infusion blade 23 has an infusion chamber. The end surface of the infusion blade 23 facing the air inlet also has a plurality of first liquid outlet holes, each communicating with the infusion chamber. The side surface of the infusion blade 23 facing the air inlet also has a plurality of second liquid outlet holes, each communicating with the infusion chamber. The infusion tube 13 has a liquid inlet hole connected to the liquid inlet box 14. The infusion tube 13 also has a liquid inlet ring groove for sliding a liquid inlet swivel. The liquid inlet swivel seals the liquid inlet ring groove and the liquid inlet hole. The liquid inlet swivel also has a connecting ring groove for connecting the liquid inlet hole and the infusion chamber.

[0047] The synthesis gas outlet box 2 is composed of two parts, which include a trapezoidal box and a rectangular box that are connected to each other from left to right. It is connected to the liquid inlet box 1 through the trapezoidal box. The hypotenuse of the trapezoidal box is downward, and the left end of the hypotenuse is connected to the bottom edge of the liquid inlet box 1, and the right end of the hypotenuse is connected to the bottom edge of the rectangular box. The hydrogen cyanide synthesis gas discharge structure is wrapped by the rectangular box.

[0048] A front shaft seat is integrally formed on the inner end face of the hypotenuse of the synthesis gas outlet box 2. The hydrogen cyanide synthesis gas discharge structure includes a clearing rotor shaft 7 and a clearing rotor cylinder 10 coaxially sleeved outside the clearing rotor shaft 7. The length of the clearing rotor shaft 7 is longer than that of the clearing rotor cylinder 10. The left end of the clearing rotor shaft 7 is rotatably mounted in the front shaft seat, and the axial direction of the clearing rotor shaft 7 is perpendicular to the inclination direction of the hypotenuse. On the outer wall of the clearing rotor shaft 7, a continuous spiral blade 15 is welded to the right along the axial direction from the end of the clearing rotor cylinder 10. A clearing delivery pipe 8 is also coaxially sleeved outside the clearing rotor shaft 7. The inner wall of the clearing delivery pipe 8 is in contact with the outer end of the inner spiral blade 15. As shown Figure 3 As shown, the left end of the installed clearing and transporting pipe 8 is flush with the left end of the clearing and transporting drum 10. A semicircular groove is provided on the upper side end face of a section of the left end of the clearing and transporting pipe 8 along the axial direction.

[0049] A number of inclined through-grooves are formed along the axial direction between the two ends of the clearing drum 10. A scraping structure driven by the clearing shaft 7 is also installed on the inner side of the clearing drum 10. The scraping structure includes a driving swivel coaxially fixedly mounted on the clearing shaft 7 at a section outside the left end of the clearing drum 10, a first driven swivel 12 mounted on the outside of the driving swivel and in contact with the inner wall of the clearing drum 10, four scraping connecting rods mounted between the first driven swivel 12 and the driving swivel, a second driven swivel 12 mounted on the inner side of the other end of the clearing drum 10 and coaxial with the first driven swivel 12, and a number of scrapers mounted between the first and second driven swivels 12 and in contact with the inner wall of the clearing drum 10.

[0050] Two receiving plates 24 are installed on the outside of the clearing shaft 7 inside the clearing drum 10, respectively installed on both sides of the semicircular groove. The receiving plates 24 are inclined toward the clearing conveying pipe 8 inside the semicircular groove. The length of the receiving plates 24 is equal to the length of the inclined through groove.

[0051] The right end of the synthesis gas outlet box 2 is provided with a clearing hole, through which the clearing conveying pipe 8 and the clearing rotor shaft 7 extend out of the synthesis gas outlet box 2. The right end of the clearing rotor cylinder 10 is fixedly mounted on the right inner wall of the synthesis gas outlet box 2. A discharge box is installed and connected to the end of the clearing conveying pipe 8 extending out of the synthesis gas outlet box 2. The discharge box has a discharge port downward and is equipped with a discharge pipe 16 connected to the discharge port. The clearing rotor shaft 7 and the spiral blade 15 extend to the discharge port. The discharge box also has a clearing shaft hole, through which the clearing rotor shaft 7 passes out of the discharge box. The discharge box also has a synthesis gas outlet facing upward, and is equipped with a synthesis gas discharge pipe 17 connected to the synthesis gas outlet.

[0052] The height of the ammonium dihydrogen phosphate solution poured into the synthesis gas outlet box 2 can only partially submerge the clearing and blocking delivery pipe 8, and cannot completely submerge the semicircular groove provided on the gas delivery pipe.

[0053] A spray structure for spraying diammonium phosphate solution is also installed in the synthesis gas outlet housing 2. The spray structure specifically comprises a spray barrel 11 mounted above the congestion-clearing rotor 10, with both ends of the spray barrel 11 sealed. A spray barrel 11 hole is provided on the right side of the synthesis gas outlet housing 2 for the spray barrel 11 to pass through. The spray barrel 11 fits against the outer wall of the congestion-clearing rotor 10 and is framed by several inclined slots. On the side of the spray barrel 11 hole that fits against the inclined slots, several spray holes are provided, arranged equidistantly along the inclined slots. The spray holes consist of a number of circular holes arranged in a honeycomb pattern, and all of the spray holes are located within the inclined slots. A circulating liquid inlet pipe 18 is connected to the end of the spray barrel 11 hole extending from the spray barrel 11 hole.

[0054] The ammonia outlet housing 3 is a special-shaped housing that encloses only the independent ammonia discharge structure and communicates with the rectangular housing within the syngas outlet housing 2. The connection encompasses a portion of the unclogging rotor cylinder 10 and the inclined slots therein. The overall length of the ammonia outlet housing 3 is the same as that of the unclogging rotor cylinder 10, and the connection with the syngas outlet housing 2 is completely sealed.

[0055] The independent ammonia exhaust structure comprises an exhaust shaft 6, an inlet pipe 18, an outlet pipe 9, and an air supply pipe, which are coaxially sleeved on the outside of the exhaust shaft 6 from bottom to top. The diameter of the inlet pipe 18 is smaller than that of the outlet pipe 9 but larger than that of the air supply pipe. An impeller is mounted on the exhaust shaft 6, located inside the left end of the inlet pipe 18. This impeller introduces a mixture of diammonium hydrogen phosphate solution and ammonium dihydrogen phosphate solution, which does not contain hydrogen cyanide synthesis gas, into the inlet pipe 18 and then into the outlet pipe 9. A heating and degassing mechanism is installed within the outlet pipe 9. This mechanism further heats the mixture introduced into the outlet pipe 9, bringing the diammonium hydrogen phosphate solution in the mixture to a reduction temperature, causing a reduction reaction to occur, expelling ammonia and producing ammonium dihydrogen phosphate solution. Following the reduction, the resulting ammonia solution and the existing ammonium dihydrogen phosphate solution in the mixture are discharged. The ammonia produced by the reduction in the outlet pipe 9 enters the air supply pipe, where it is discharged and subsequently processed and collected using subsequent equipment.

[0056] A rear shaft seat is integrally formed on the inner wall of the left end of the ammonia outlet box 3 for rotatably mounting the exhaust shaft 6.

[0057] An energy supply housing 5 is mounted on the left side of the ammonia outlet housing 3. A cylindrical receiving groove is coaxially formed inwardly from the left end of the exhaust shaft 6. An electric heating rod 22 is mounted within the groove, with a heat-conducting layer interposed between the heating rod 22 and the inner wall of the groove. A power supply structure for supplying power to the heating rod 22 is mounted within the functional housing. The heating rod 22 passes through the ammonia outlet housing 3 and is fitted with a conductive ring at its left end. A water-blocking collar is attached to the heating rod 22 to the right of the conductive ring. The power supply structure supplies power to the conductive ring and to the heating rod 22, generating heat to reach the reduction temperature of the diammonium hydrogen phosphate. In this embodiment, the temperature is maintained between 373°K and 393°K.

[0058] like Figure 3As shown, the diameter of the air outlet pipe 9 is larger than the diameter of the liquid inlet pipe 18. A cover plate is installed at each end of the air outlet pipe 9. An exhaust hole is coaxially opened on the cover plate for the exhaust shaft 6 to pass through. A temperature-raising and air-release structure is installed in the air outlet pipe 9 between the cover plates. Specifically, the internal space of the air outlet pipe 9 is a convex circle, the exhaust hole is opened at the center of the convex circle, and the longest radius of the air outlet pipe 9 is equal to twice the shortest radius. The temperature-raising and air-release structure includes eight active plates 20 circumferentially fixed to the outside of the exhaust shaft 6 and driven plates 19 installed inside the active plates 20. A driven slide for the driven plate 19 to slide into is installed on the outside of the active plate 20. The length of the active plate 20 is equal to the shortest radius, and the length of the driven plate 19 is equal to the length of the active plate 20. Both ends of the active plate 20 and the driven plate 19 are respectively in contact with the inner walls of the cover plates at both ends. Driven protrusions are integrally formed at both ends of the outer side of the driven plate 19, and active guide grooves with the same convex contour as the convex circle are respectively opened on the inner walls of the cover plates at both ends. The driven protrusions are placed in the active guide grooves and can slide inside.

[0059] A reduction liquid inlet is provided on the cover plate at the lower end of the outlet pipe 9. In this example, as the exhaust shaft 6 rotates clockwise, the shortest side of the outlet pipe 9 is positioned above its longest side. The reduction liquid inlet is located on the outlet pipe 9, increasing in radius in a clockwise direction. An ammonia gas outlet is provided on the cover plate at the top of the outlet pipe 9, increasing in radius in a clockwise direction. A reduction liquid outlet is provided on the outlet pipe 9, decreasing in radius in a clockwise direction. The ammonia gas outlet is connected to the gas supply pipe, which has a through hole on one side of the top end for the discharged ammonia gas to be discharged. The gas supply pipe has an exhaust shaft hole for the exhaust shaft 6 to pass through.

[0060] A bracket is built through the external environment at the right end of the synthesis gas outlet box 2, and a support plate is installed on the bracket. A drive motor is installed on the support plate. A belt transmission mechanism is also installed between the exhaust shaft 6 and the clearing shaft 7. An axial hole is opened on the support plate for the clearing shaft 7 and the output shaft of the drive motor to pass through. The output shaft of the drive motor is coaxially connected to the exhaust shaft 6.

[0061] The reduction liquid outlet on the outlet pipe 9 is connected to a main liquid supply pipe. A three-way valve is installed at the end of the main liquid supply pipe, through which a first and second auxiliary liquid supply pipes are connected. The first auxiliary liquid supply pipe is connected to the liquid inlet on the liquid inlet box 14, and the second auxiliary liquid supply pipe is connected to the circulation liquid inlet pipe 18 on the spray barrel 11. In this example, several heat conducting plates 21 are also mounted along the axis of the exhaust shaft 6 located inside the liquid inlet pipe 18. The outer walls of the heat conducting plates 21 are in contact with the inner wall of the liquid inlet pipe 18 and are arranged from the inner side of the impeller to the inner wall of the right end of the ammonia outlet box 3. The main liquid supply pipe, the first auxiliary liquid supply pipe, and the second auxiliary liquid supply pipe form a reflux structure.

[0062] The ammonia pyrolysis structure is composed of the liquid inlet pipe 18, the gas outlet pipe 9, the exhaust shaft 6 and the electric heating rod 22 installed in the exhaust shaft 6, and the ammonia discharge structure is composed of the active plate 20, the driven plate 19, the gas outlet pipe 9 and the gas transmission pipe.

[0063] When the ammonia removal device of the present invention is used, an appropriate amount of ammonium dihydrogen phosphate solution is first introduced into the reaction box so that the liquid level is higher than the liquid inlet box 14 but does not completely submerge the semicircular groove. The most suitable liquid level is flush with the bottom of the leftmost semicircular groove.

[0064] Then, the power supply structure is powered on, and the temperature of the solution in the ammonia outlet box 3 is increased by heating the electric heating rod 22. The drive motor is started to rotate the exhaust shaft 6 and the blockage clearing shaft 7. After water flow is observed to enter the main liquid supply pipe, hydrogen cyanide synthesis gas containing ammonia is introduced.

[0065] The hydrogen cyanide synthesis gas first contacts the ammonium dihydrogen phosphate solution in the liquid inlet tank, and the ammonium dihydrogen phosphate solution absorbs the ammonia carried by the hydrogen cyanide synthesis gas. Since hydrogen cyanide is insoluble in the ammonium dihydrogen phosphate solution, the hydrogen cyanide is quickly discharged from the ammonium dihydrogen phosphate solution and is located in the upper space between the liquid inlet tank and the synthesis gas outlet box 2. The ammonium dihydrogen phosphate solution reacts with the ammonia to produce diammonium hydrogen phosphate solution.

[0066] When the exhaust shaft 6 rotates, it drives the impeller to rotate synchronously, and the mixed liquid of the diammonium hydrogen phosphate solution and the ammonium dihydrogen phosphate solution in the synthesis gas outlet box 2 is introduced into the liquid inlet pipe 18. The mixed liquid in the synthesis gas outlet box 2 enters the ammonia outlet box 3 after being filtered by the cleaning rotor 10. The rotation of the cleaning rotor 7 drives the synchronous rotation of the scraping structure, and the scraper cleans the suspended matter, large particles and complexes filtered by the cleaning rotor 10. When the scraper moves to the top, the scraped debris falls into the receiving plate 24 below, slides into the cleaning conveying pipe 8 through the receiving plate 24, is carried out by the rotation of the spiral blade 15, and is discharged through the discharge port;

[0067] The rotation of the exhaust shaft 6 also drives the synchronous rotation of the heating and degassing structure. The electric heating rod 22 heats the diammonium hydrogen phosphate solution to the reduction temperature, causing the diammonium hydrogen phosphate to undergo a reduction reaction in the liquid inlet pipe 18 and the gas outlet pipe 9, thereby discharging ammonia gas. The ammonia gas is discharged through the gas pipe, while the reduced diammonium hydrogen phosphate solution and a portion of the unreduced diammonium hydrogen phosphate mixture are discharged into the reduction liquid outlet through the rotation of the active plate 20 and the driven plate 19, and then discharged into the liquid inlet assembly through the first auxiliary liquid supply pipe and into the spray structure through the second auxiliary liquid supply pipe.

[0068] The solution discharged into the liquid inlet assembly will be discharged through the infusion structure. During the discharge, the infusion blades 23 will rotate and spray the solution outward. The solution will be sprayed toward the air inlet, contact the ammonia-containing synthesis gas, and directly absorb the ammonia. The rotation of the infusion blades 23 will stir the solution, thereby increasing the adsorption efficiency.

[0069] The solution discharged into the spray structure will be sprayed out from each covered inclined groove through the spray barrel 11 hole on the spray barrel 11, and sprayed downward to form a spray. During the rotation of the exhaust shaft 6, the spray can contact the scraper to remove debris attached to the scraper. When spraying downward, it contacts the hydrogen cyanide synthesis gas in the upper space of the synthesis gas outlet box 2. The escaping ammonia is absorbed by the ammonium dihydrogen phosphate solution and falls to the bottom. Part of the solution falls on the receiving plate 24 and can also push the debris accumulated on the receiving plate 24 to the clearing conveying pipe 8 and be delivered by the spiral blade 15.

[0070] The filtered hydrogen cyanide synthesis gas is discharged from the clearing and delivery pipe 8, completing the pretreatment of the hydrogen cyanide synthesis gas.

[0071] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A component pretreatment method for hydrocyanic acid synthesis gas, characterized by: The steps include: Step S1: introducing ammonium dihydrogen phosphate solution into the ammonia removal equipment and starting the ammonia removal equipment; Step S2: introducing hydrogen cyanide synthesis gas containing ammonia into the ammonia removal equipment, where the ammonia reacts with the ammonium dihydrogen phosphate solution to produce diammonium hydrogen phosphate, which is retained in the ammonia removal equipment. The hydrogen cyanide synthesis gas is directly discharged from the ammonia removal equipment. Step S3: The remaining diammonium hydrogen phosphate solution is thermally decomposed by the ammonia removal device to generate ammonia gas and diammonium dihydrogen phosphate solution, the ammonia gas is discharged separately, and the diammonium dihydrogen phosphate solution is refluxed into the ammonia removal device to reabsorb the hydrogen cyanide synthesis gas containing ammonia gas; The ammonia removal equipment includes a reaction box for containing diammonium hydrogen phosphate solution and an exhaust assembly installed in the reaction box. One side of the reaction box is connected to an air inlet pipe for unidirectionally introducing ammonia-containing synthesis gas into the diammonium hydrogen phosphate solution. The exhaust assembly includes, in sequence along the gas injection direction, a hydrogen cyanide synthesis gas exhaust structure for exhausting hydrogen cyanide synthesis gas and an ammonia independent exhaust structure for pyrolyzing diammonium hydrogen phosphate and independently exhausting ammonia gas; The hydrogen cyanide synthesis gas discharge structure includes a clearing rotor arranged obliquely in the reaction box along the gas injection direction, a clearing delivery pipe coaxially arranged inside the clearing rotor, and a clearing rotor shaft coaxially arranged inside the clearing delivery pipe. A scraping structure for cleaning the inner wall of the clearing rotor is fixedly connected to the clearing rotor shaft. A spiral blade that fits the inner wall of the clearing delivery pipe is fixedly connected to the clearing rotor shaft along the axial direction. The clearing delivery pipe is provided with a semicircular groove with the top exposed to the liquid surface. A plurality of inclined through grooves are provided circumferentially between the two ends of the clearing rotor. The ammonia independent exhaust structure includes an ammonia pyrolysis structure and an ammonia exhaust structure which are arranged in the reaction box and are sequentially connected. The ammonia pyrolysis structure is also connected to a reflux structure for discharging the diammonium dihydrogen phosphate solution generated by pyrolysis and supplying it into the reaction box. The reaction box is provided with an ammonia outlet box body for wrapping the ammonia pyrolysis structure and the inclined through slot on the lower side of the clearing rotor. The reaction box is also fixed with a driving structure for driving the clearing rotor shaft to rotate.

2. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 1, characterized in that: The reaction box is further provided with a liquid inlet component connected to the air inlet pipe, and the reflux structure is connected to the liquid inlet component and is supplied with ammonium dihydrogen phosphate solution.

3. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 2, characterized in that: The liquid inlet assembly includes an infusion structure fixedly connected to the reaction box and a liquid inlet box fixedly connected to the reaction box and supplied with liquid by a reflux structure. The infusion structure includes an infusion tube connected to the air inlet pipe, support frames fixedly connected to both ends of the infusion tube, and an infusion mechanism arranged between the support frames at both ends. The infusion tube is provided with a liquid inlet through hole for connecting the liquid inlet box and the infusion mechanism.

4. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 3, characterized in that: The infusion mechanism includes an infusion shaft coaxially connected between support frames at both ends and an infusion blade circumferentially fixed to the infusion shaft. A liquid inlet swivel for fixing the outer end of the infusion blade is rotatably connected to the inner side of the infusion tube. An infusion chamber is provided in each of the infusion blades. A connecting ring groove for connecting the infusion chamber and the liquid inlet through hole is provided on the liquid inlet swivel. A plurality of first liquid outlet holes respectively connected to the infusion chamber are provided on the end of the infusion blade facing the air inlet pipe.

5. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 4, characterized in that: The infusion blades are all uniformly arranged to tilt toward one side, and the end surfaces of the infusion blades facing the air inlet pipe are each provided with a plurality of second liquid outlet holes respectively communicated with the infusion chambers.

6. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 1, characterized in that: The reaction box is also provided with a spray structure for flushing and clearing the blocked rotor, and a second auxiliary liquid supply pipe is connected between the spray structure and the reflux structure for introducing diammonium dihydrogen phosphate solution.

7. The component pretreatment method for hydrocyanic acid synthesis gas according to claim 6, characterized in that: The spray structure is arranged above the blockage clearing drum. The spray structure is a spray barrel connected to the second auxiliary liquid supply pipe and covering multiple inclined slots. The spray barrel is provided with a number of spray holes equidistantly corresponding to the inclined slots.

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