Potassium nitrate production system
By introducing a pyrolysis furnace and heat exchanger into the potassium nitrate production system, the problem of low ammonium chloride utilization rate was solved, and the recycling of ammonia and the reuse of thermal energy were realized, thereby improving the economic efficiency and environmental friendliness of potassium nitrate production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2026-03-20
AI Technical Summary
The utilization rate of ammonium chloride, a byproduct of existing potassium nitrate production processes, is low, resulting in low profit margins for enterprises and accumulation of byproducts. In addition, traditional processes suffer from high energy consumption and the introduction of impurities.
By introducing a thermal decomposition furnace into the potassium nitrate production system, ammonium chloride is thermally decomposed to generate pure ammonia and hydrogen chloride gas. The heat energy is then recovered using the first and second heat exchangers for power generation, thus realizing the recycling of ammonia and the reuse of heat energy.
This technology enables the efficient utilization of ammonium chloride, reduces the production cost of potassium nitrate, increases the company's profit margin, and reduces energy consumption through heat recovery power generation, avoids the introduction of impurities, and achieves green and environmentally friendly circular production.
Smart Images
Figure CN224015313U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of potassium nitrate preparation technology, specifically a potassium nitrate production system. Background Technology
[0002] Currently, the main production processes for potassium nitrate in China are ion exchange, magnesium nitrate, and ammonium nitrate. Among them, the ion exchange method has high investment and high energy consumption and has been basically phased out; the magnesium nitrate method has low investment and short process, but the by-product of 1 t / t of magnesium chloride hexahydrate is difficult to treat and the overall economic benefits are poor; based on this, the ammonium nitrate method has become the mainstream process for preparing potassium nitrate, which has the characteristics of low investment, short process and less pollution. Its general process flow is as follows: (1) Dissolve potassium chloride in water and filter the dissolved potassium chloride; (2) Prepare ammonium nitrate and add the ammonium nitrate to the filtered potassium chloride solution; (3) Crystallize and centrifuge the potassium chloride solution with added ammonium nitrate. Crude potassium nitrate is obtained, and the crude potassium nitrate is refined in the subsequent process; (4) the mother liquor after centrifugation is concentrated and evaporated to obtain ammonium chloride slurry; (5) the obtained ammonium chloride slurry is centrifuged and dried to obtain by-product ammonium chloride; it can be seen from the above process flow that the preparation of potassium nitrate by ammonium nitrate will produce ammonium chloride by-product; it is calculated that 0.3 tons of ammonium chloride can be produced by-product by ton of potassium nitrate during the production process, that is, the production of potassium nitrate will cause a large amount of by-product accumulation. The capacity of the entire ammonium chloride industry is less than 2%, and its profit margin is low. It has no advantage as fertilizer or as industrial raw material for external sale. Utility Model Content
[0003] To overcome the above deficiencies, this utility model provides a potassium nitrate production system to solve the technical problems existing in the prior art.
[0004] The technical solution adopted by this utility model to solve its technical problem is:
[0005] A potassium nitrate production system includes an ammonium nitrate production unit connected to an ammonia pipeline. The ammonium nitrate pipeline in the ammonium nitrate production unit is connected to the potassium nitrate production unit. The by-product outlet of the potassium nitrate production unit is connected to an ammonium chloride storage tank. The ammonium chloride storage tank is connected to a pyrolysis furnace. The ammonia outlet of the pyrolysis furnace is connected to an ammonia compressor through a first heat exchange channel of a first heat exchanger. The outlet of the ammonia compressor is connected to a tee valve installed on the ammonia pipeline.
[0006] The beneficial effects of this invention are as follows: ammonium chloride is thermally decomposed in a thermal decomposition furnace to obtain ammonia, which is then used as a raw material for preparing ammonium nitrate, thus achieving the characteristic of cyclic preparation of potassium nitrate. Furthermore, the first heat exchanger not only recovers the heat energy of ammonia during thermal decomposition to prepare for subsequent compression and recycling, but also enables the utilization of heat energy. Furthermore, this invention avoids the introduction of impurities through thermal decomposition, thus obtaining pure ammonia, laying the foundation for the direct utilization of ammonia.
[0007] Preferably, the top of the pyrolysis furnace is provided with a gas phase outlet pipe, the inside of the gas phase outlet pipe is provided with a filter, the top of the gas phase outlet pipe is provided with a separator, and the upper gas phase outlet of the separator is connected to the inlet of the first heat exchange channel of the first heat exchanger.
[0008] Preferably, the lower outlet of the separator is connected to the first heat exchange channel of the second heat exchanger, and the outlet of the first heat exchange channel of the second heat exchanger is connected to the hydrogen chloride storage tank via a compressor.
[0009] Preferably, a molecular sieve is provided at the lower outlet of the separator.
[0010] Preferably, the second channel inlet of the first heat exchanger and the second channel inlet of the second heat exchanger are respectively connected to the demineralized water storage tank, and the second channel outlet of the first heat exchanger and the second channel outlet of the second heat exchanger are respectively connected to the ORC waste heat power generation unit.
[0011] Preferably, a powder pump is provided between the ammonium chloride storage tank and the pyrolysis furnace.
[0012] A potassium nitrate production system prepared according to the above technical solution can thermally decompose ammonium chloride, a byproduct of the potassium nitrate production unit, thereby recovering ammonia gas from the ammonium chloride and using the ammonia gas as a raw material for the production of ammonium nitrate, thus achieving the characteristic of cyclical production of potassium nitrate and reducing raw material purchase costs. In addition, this utility model uses a thermal decomposition furnace to thermally decompose ammonium chloride, which has the advantages of being green and environmentally friendly, producing no waste liquid or waste residue, and does not introduce impurities. The produced ammonia gas is relatively pure, making it convenient for recycling. Furthermore, the thermal decomposition of ammonium chloride in the thermal decomposition furnace can also produce relatively pure hydrogen chloride gas as a byproduct, which can be sold to increase the company's profit margin. At the same time, this utility model also includes a first heat exchanger and a second heat exchanger, which can exchange heat between the ammonia gas and hydrogen chloride gas decomposed by the thermal decomposition furnace. This not only facilitates the reuse and storage of ammonia gas and hydrogen chloride gas, but also enables the use of thermal energy for power generation, thus achieving the characteristics of energy saving and environmental protection. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a flowchart illustrating the process of this utility model.
[0015] Figure 2 This is a schematic diagram of the structure of the pyrolysis furnace of this utility model.
[0016] In the diagram: 1. Ammonia pipeline; 2. Ammonium nitrate production unit; 3. Potassium nitrate production unit; 4. Ammonium chloride storage tank; 5. Thermal decomposition furnace; 6. First heat exchanger; 7. Ammonia compressor; 8. Gas phase outlet pipeline; 9. Filter; 10. Separator; 11. Second heat exchanger; 12. Compressor; 13. Hydrogen chloride storage tank; 14. Molecular sieve; 15. ORC waste heat power generation unit; 16. Powder pump; 17. Demineralized water storage tank. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0018] The following is in conjunction with the appendix Figure 1-2This application provides a detailed description of a potassium nitrate production system. The system includes an ammonium nitrate production unit 2 connected to an ammonia pipeline 1. An ammonium nitrate pipeline in the ammonium nitrate production unit 2 is connected to a potassium nitrate production unit 3. The byproduct outlet of the potassium nitrate production unit 3 is connected to an ammonium chloride storage tank 4. The ammonium chloride storage tank 4 is connected to a thermal decomposition furnace 5. The ammonia outlet of the thermal decomposition furnace 5 is connected to an ammonia compressor 7 via a first heat exchange channel of a first heat exchanger 6. The outlet of the ammonia compressor 7 is connected to a tee valve installed on the ammonia pipeline 1. This invention utilizes the thermal decomposition furnace 5 to thermally decompose ammonium chloride from the ammonium chloride storage tank 4. The thermal decomposition reaction principle is: NH4Cl → NH3 + HCl (ammonium chloride decomposition temperature is 340℃). No impurities are introduced during this process, therefore the ammonia and hydrogen chloride gases are relatively pure and can be directly used for the preparation and sale of ammonium nitrate without the need for impurity removal. The first heat exchanger 6 in this invention can perform heat exchange treatment on ammonia gas to meet the needs of subsequent ammonium nitrate production. The main equipment of the ammonium nitrate production unit 2 in this invention includes a liquid ammonia evaporator, a gaseous ammonia fine filter, a tubular reactor, a neutralization and washing tower, a tail gas washing tower, an ammonia absorption tower, etc. The main equipment of the potassium nitrate production unit 3 includes a triple-effect evaporator, an ammonium chloride crystallizer, an ammonium chloride centrifuge, an ammonium chloride dryer, a potassium mixing tank, a thickener, a potassium nitrate dryer, etc. The above are conventional setups in this field, which can be purchased directly on the market and are not the focus of protection of this invention, so they will not be described in detail.
[0019] Furthermore, the top of the pyrolysis furnace 5 is provided with a gas phase outlet pipe 8, the inside of which is a filter 9, and the top of the gas phase outlet pipe 8 is provided with a separator 10. The upper gas phase outlet of the separator 10 is connected to the inlet of the first heat exchange channel of the first heat exchanger 6. In this invention, the filter 9 is preferably a high-temperature flat plate filter, and the separator 10 is preferably a vertical gravity separator inclined at 30-70°. This type of separator can separate and collect the two gases by allowing them to escape in two directions, upward and downward, according to the density and viscosity differences.
[0020] Furthermore, the lower outlet of the separator 10 is connected to the first heat exchange channel of the second heat exchanger 11, and the outlet of the first heat exchange channel of the second heat exchanger 11 is connected to the hydrogen chloride storage tank 13 via the compressor 12. This invention recovers heat from the hydrogen chloride gas decomposed in the pyrolysis furnace 5 through the second heat exchanger 11, and simultaneously pressurizes it through the compressor 12, enabling it to enter the hydrogen chloride storage tank 13 for convenient external sale.
[0021] Furthermore, a molecular sieve 14 is provided at the lower outlet of the separator 10. The molecular sieve 14 is preferably a JMT type mordenite molecular sieve.
[0022] Furthermore, the second channel inlet of the first heat exchanger 6 and the second channel inlet of the second heat exchanger 11 are respectively connected to the demineralized water storage tank 17, and the second channel outlet of the first heat exchanger 6 and the second channel outlet of the second heat exchanger 11 are respectively connected to the ORC waste heat power generation unit 15. The heat recovered by the first heat exchanger 6 and the second heat exchanger 11 can be used for power generation in the ORC waste heat power generation unit 15, thereby realizing the recovery and reuse of thermal energy. The ORC waste heat power generation unit 15 mainly includes a turbine, generator, evaporator, condenser, and other equipment; these are conventional setups in the field and can be purchased directly from the market, and are not the focus of this invention, so they will not be described in detail here.
[0023] Furthermore, a powder pump 16 is provided between the ammonium chloride storage tank 4 and the thermal decomposition furnace 5.
[0024] The specific working process of this utility model is as follows: Ammonia gas from ammonia pipeline 1 is used as raw material to enter ammonium nitrate production unit 2 for the production of ammonium nitrate. Ammonium nitrate is used as raw material to enter potassium nitrate production unit 3 for the production of potassium nitrate. Simultaneously, during the potassium nitrate production process, the byproduct solid ammonium chloride powder is pumped into thermal decomposition furnace 5 by pump 16 for thermal decomposition. The reaction principle of thermal decomposition is: NH4Cl → NH3 + HCl (ammonium chloride decomposition temperature is 340℃). The thermal decomposition furnace 5 is heated internally by heat transfer oil, with an operating temperature of 350-400℃ and an operating pressure of slightly negative pressure (vacuum operation, which can prevent air from entering and affecting the purity and separation effect of ammonia and hydrogen chloride gases). It contains a gas separation membrane and a molecular sieve. The gas phase from thermal decomposition is filtered through filter 9 in gas phase outlet pipeline 8 and then sent into separator 10 for further processing. The separated ammonia gas (at atmospheric pressure, temperature 350-400℃) is heated by the first heat exchanger 6 to a temperature of 60-100℃. After being pressurized to 0.2-0.4MPa by the ammonia compressor 7, it is sent to the ammonium nitrate production unit 2 as a raw material. The separated hydrogen chloride gas (at atmospheric pressure, temperature 350-400℃) is heated by the second heat exchanger 11 to a temperature of 60-100℃. After being pressurized to 0.8-1.2MPa by the compressor 12, it enters the hydrogen chloride storage tank 13 for sale. The steam produced in the first heat exchanger 6 and the second heat exchanger 11 enters the ORC waste heat power generation unit 15 for power generation. The above process has the advantages of saving the preparation cost of potassium nitrate, realizing the recycling of potassium nitrate, and the high purity of hydrogen chloride decomposed by the thermal decomposition furnace 5, which is convenient for sale and increases corporate profits.
[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.
Claims
1. A potassium nitrate production system comprising an ammonium nitrate production unit (2) connected to an ammonia pipeline (1), an ammonium nitrate pipeline in the ammonium nitrate production unit (2) connected to a potassium nitrate production unit (3), and a by-product outlet of the potassium nitrate production unit (3) connected to an ammonium chloride storage tank (4), characterized in that: The ammonium chloride storage tank (4) is connected to the pyrolysis furnace (5). The ammonia outlet of the pyrolysis furnace (5) is connected to the ammonia compressor (7) through the first heat exchange channel of the first heat exchanger (6). The outlet of the ammonia compressor (7) is connected to a tee set on the ammonia pipeline (1).
2. The potassium nitrate production system according to claim 1, characterized in that: The top of the pyrolysis furnace (5) is provided with a gas phase outlet pipe (8), the inside of the gas phase outlet pipe (8) is provided with a filter (9), the top of the gas phase outlet pipe (8) is provided with a separator (10), and the upper gas phase outlet of the separator (10) is connected to the inlet of the first heat exchange channel of the first heat exchanger (6).
3. A potassium nitrate production system according to claim 2, characterized in that: The lower outlet of the separator (10) is connected to the first heat exchange channel of the second heat exchanger (11), and the outlet of the first heat exchange channel of the second heat exchanger (11) is connected to the hydrogen chloride storage tank (13) through the compressor (12).
4. A potassium nitrate production system according to claim 3, characterized in that: A molecular sieve (14) is provided at the lower outlet of the separator (10).
5. A potassium nitrate production system according to claim 3, characterized in that: The second channel inlet of the first heat exchanger (6) and the second channel inlet of the second heat exchanger (11) are respectively connected to the demineralized water storage tank (17), and the second channel outlet of the first heat exchanger (6) and the second channel outlet of the second heat exchanger (11) are respectively connected to the ORC waste heat power generation unit (15).
6. A potassium nitrate production system according to claim 1, characterized in that: A powder pump (16) is provided between the ammonium chloride storage tank (4) and the pyrolysis furnace (5).