A novel ammonia water gasification system for flue gas denitration
By using steam as a heat source in the denitrification process, combined with a stripping tower and a condenser, the dependence of traditional ammonia water gasification on high-temperature flue gas was solved, achieving medium- and low-temperature ammonia water gasification, reducing the ammonia water vapor content, avoiding equipment corrosion and catalyst pulverization, and improving system energy efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YIZHONG GRP DALIAN ENG CONSTR CO LTD
- Filing Date
- 2025-07-30
- Publication Date
- 2026-06-26
AI Technical Summary
Traditional ammonia gasification processes are heavily reliant on high-temperature flue gas and cannot be applied in denitrification processes that lack high-temperature flue gas. Furthermore, moisture during ammonia gasification causes corrosion of denitrification equipment and catalyst pulverization.
Using steam, commonly found in factories and mines, as a heat source, combined with a stripping tower and a condenser, the water vapor content in ammonia is reduced through gas-liquid mass transfer and condensation processes. A static mixer is used to adjust the ammonia concentration, thereby achieving medium- and low-temperature ammonia-water vaporization.
The efficient vaporization of ammonia water was achieved under medium and low temperature conditions, which reduced the water vapor content in the ammonia gas, avoided equipment corrosion and catalyst pulverization, and improved energy utilization efficiency.
Smart Images
Figure CN224404805U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of environmental protection engineering equipment and relates to the denitrification reducing agent generation technology, specifically a novel ammonia water gasification system for flue gas denitrification. Background Technology
[0002] Currently, in the field of flue gas denitrification technology, ammonia-containing substances such as liquid ammonia, ammonia water, and urea are widely used as precursors for denitrification reducing agents. These substances are converted into ammonia gas through gasification or hydrolysis reactions and then used as the denitrification reducing agent. Among these, ammonia water has become a widely chosen industrial application due to its low hazard, ease of gasification, and low price: Firstly, compared to high-pressure stored liquid ammonia, ammonia water offers greater safety in storage and transportation; secondly, compared to urea, ammonia water does not require complex hydrolysis reaction equipment, making the gasification process simpler; and thirdly, the raw material cost of ammonia water is relatively low, offering significant economic advantages. Traditional ammonia water gasification processes typically employ atomization spray technology, where ammonia water is atomized through a specialized nozzle and directly sprayed into high-temperature flue gas or hot air to achieve instantaneous gasification. However, this process has stringent requirements for heat source temperature, relying on high-temperature flue gas as the gasification heat source. Some denitrification processes, such as activated carbon desulfurization and denitrification processes, do not have high-temperature flue gas and cannot directly utilize this type of ammonia-water gasification process. Furthermore, during gasification, the moisture in the ammonia water will vaporize simultaneously with the ammonia gas and enter the denitrification reactor, potentially leading to corrosion of the reactor's inner wall or catalyst pulverization and deactivation. Therefore, it is necessary to develop an ammonia-water gasification technology that uses a conventional heat source and produces a low moisture content after gasification. Utility Model Content
[0003] To address the shortcomings of existing technologies, this invention provides a novel ammonia water gasification system for flue gas denitrification. It uses steam, commonly found in factories and mines, as a heat source, making it highly adaptable. Furthermore, the ammonia gas produced after ammonia water gasification has a low water content, effectively reducing the corrosion of the inner wall of the denitrification equipment and the pulverization of the catalyst caused by water vapor in the ammonia gas.
[0004] The technical solution adopted by this utility model to solve its technical problem is:
[0005] A novel ammonia-water gasification system for flue gas denitrification includes: a stripping tower, a steam supply unit, a preheater, an ammonia-water supply unit, a condenser, an air supply unit, and a static mixer; the ammonia-water supply unit is connected to the working fluid inlet of the preheater, and the working fluid outlet of the preheater is connected to the ammonia-water inlet of the stripping tower; the steam supply unit is connected to the steam inlet of the stripping tower; the ammonia outlet at the top of the stripping tower is connected to the inlet of the condenser, and the wastewater outlet at the bottom of the stripping tower is connected to the heat medium inlet of the preheater; the gas outlet of the condenser is connected to the static mixer to transport the condensed ammonia gas into the static mixer; the liquid outlet of the condenser is connected to the reflux liquid inlet at the top of the stripping tower to return the condensate to the stripping tower for gas-liquid mass transfer; the air supply unit is connected to the static mixer to mix air and ammonia gas in the static mixer to adjust the ammonia gas concentration.
[0006] Furthermore, the ammonia supply unit includes an ammonia pump, an ammonia flow regulating valve, and an ammonia supply pipeline; the inlet end of the ammonia pump is connected to an ammonia storage device via a pipeline, and the outlet end is connected to the working fluid inlet of the preheater via the ammonia supply pipeline; the ammonia supply pipeline is equipped with an ammonia flow regulating valve to regulate the ammonia flow rate.
[0007] Furthermore, the steam supply unit includes a steam flow regulating valve and a steam supply pipeline. One end of the steam supply pipeline is connected to a steam source, and the other end is connected to the steam inlet of the stripping tower. The steam flow regulating valve is located on the steam supply pipeline and is electrically connected to the temperature controller (TIC) at the top of the stripping tower to control the steam flow.
[0008] Furthermore, the heat medium outlet at the bottom of the preheater is connected to a wastewater discharge pipe, and a liquid level regulating valve is installed on the wastewater discharge pipe. The liquid level regulating valve is electrically connected to the liquid level controller LIC at the bottom of the stripping tower to regulate the wastewater flow rate.
[0009] Furthermore, the air supply unit includes a fan and an air heater; the fan inlet is connected to an air source, the fan outlet is connected to the air heater inlet, and the air heater outlet is connected to a static mixer.
[0010] Furthermore, the heat source inlet of the air heater is connected to a steam source, using steam as the heat source for heating the air.
[0011] The beneficial effects of this utility model include:
[0012] This system combines a stripping tower with a condenser, utilizing conventional steam from the plant as a heat source to achieve highly efficient ammonia vaporization under medium- and low-temperature conditions. It is particularly suitable for denitrification processes lacking high-temperature flue gas. Through gas-liquid mass transfer within the stripping tower and partial condensation in the condenser, the water vapor content in the produced ammonia is reduced, effectively mitigating corrosion and catalyst pulverization issues in the denitrification equipment. The system utilizes the high-temperature wastewater discharged from the stripping tower to preheat the raw ammonia, improving energy efficiency.
[0013] The system utilizes the steam heat source as both a heat source for the stripping tower and for air heating, further optimizing system energy consumption. The temperature controller (TIC) maintains a stable temperature at the top of the stripping tower by adjusting the steam flow valve, ensuring gasification efficiency; the level controller (LIC) maintains liquid level balance within the tower by controlling the wastewater discharge valve, ensuring continuous system operation. Attached Figure Description
[0014] Figure 1 This is an overall structural diagram of a novel ammonia-water gasification system for flue gas denitrification according to this utility model.
[0015] In the diagram: 1-Stripping tower; 2-Steam flow regulating valve; 3-Preheater; 4-Ammonia water flow regulating valve; 5-Ammonia water pump; 6-Condenser; 7-Liquid level regulating valve; 8-Air heater; 9-Static mixer; 10-Fan. Detailed Implementation
[0016] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0017] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0018] Example 1: A novel ammonia water gasification system for flue gas denitrification uses steam, commonly found in industrial and mining enterprises, as a heat source, making it highly adaptable. The ammonia gas after gasification has a low water content, effectively reducing the corrosion of the denitrification equipment's inner walls and the pulverization of the catalyst caused by water vapor in the ammonia gas. (Reference) Figure 1 It includes: 1. stripping tower, 2. steam flow regulating valve, 3. preheater, 4. ammonia water flow regulating valve, 5. ammonia water pump, 6. condenser, 7. liquid level regulating valve, 8. air heater, 9. static mixer, and 10. fan.
[0019] The inlet of the ammonia pump 5 is connected to the ammonia storage device via a pipeline, and the outlet is connected to the working fluid inlet of the preheater 3 via an ammonia supply pipeline. The ammonia supply pipeline is equipped with an ammonia flow regulating valve 4, which is used to regulate the ammonia flow rate by adjusting the opening of the ammonia flow regulating valve 4, thereby regulating the operating load of the ammonia gasification system. The working fluid outlet of the preheater 3 is connected to the ammonia inlet of the stripping tower 1.
[0020] One end of the steam supply pipeline is connected to the steam source, and the other end is connected to the steam inlet of the stripping tower 1; the steam flow regulating valve 2 is installed on the steam supply pipeline and is electrically connected to the temperature controller TIC at the top of the stripping tower 1, so as to control the steam flow through the opening of the steam flow regulating valve 2, thereby controlling the temperature at the top of the stripping tower 1 to stabilize.
[0021] The steam inlet of the stripping tower 1 is located below the ammonia inlet of the stripping tower 1; the interior of the stripping tower 1 is a tray structure, a packing structure or other structure, providing a large gas-liquid contact area;
[0022] The ammonia outlet at the top of stripping tower 1 is connected to the inlet of condenser 6, and the wastewater outlet at the bottom of stripping tower 1 is connected to the heat medium inlet of preheater 3; the heat medium outlet at the bottom of preheater 3 is connected to the wastewater discharge pipe; heat recovery and utilization are achieved through heat exchange between ammonia water and wastewater in preheater 3; a liquid level regulating valve 7 is installed on the wastewater discharge pipe, and the liquid level regulating valve 7 is electrically connected to the liquid level controller LIC at the bottom of stripping tower 1, which is used to regulate the wastewater flow rate by adjusting the opening of the liquid level regulating valve 7, thereby controlling the liquid level of stripping tower 1 to be stable;
[0023] The gas outlet of condenser 6 is connected to static mixer 9 to deliver condensed ammonia gas into static mixer 9; the liquid outlet of condenser 6 is connected to the reflux liquid inlet at the top of stripper 1. In condenser 6, the mixture of ammonia gas and water vapor is condensed by circulating cooling water to produce condensate. The condensate is returned to stripper 1 for gas-liquid mass transfer. The reflux flow rate of condensate is controlled by adjusting the flow rate of circulating cooling water.
[0024] The inlet of the blower 10 is connected to an air source, the outlet of the blower 10 is connected to the inlet of the air heater 8, and the outlet of the air heater 8 is connected to the static mixer 9. The static mixer 9 is used to mix air and ammonia to adjust the ammonia concentration in the denitrification reducing agent. The heat source inlet of the air heater 8 is connected to a steam source, and steam is used as the heat source to heat the air. The air is heated by the air heater 8 to reach a suitable temperature and optimize the mixing stability. The steam releases latent heat in the air heater 8 and then condenses into water and is discharged.
[0025] During system operation, ammonia water is pumped by ammonia water pump 5 to preheater 3. After heat exchange and temperature increase in preheater 3, it enters stripping tower 1, and the ammonia water flow rate is controlled by ammonia water flow regulating valve 4. Steam is supplied to the lower part of stripping tower 1 through steam supply pipeline, heating the liquid ammonia water to boiling. The resulting ammonia-containing steam flows towards the top of the tower, forming an upward airflow. The steam flow rate is controlled by steam flow regulating valve 2, ultimately stabilizing the temperature at the top of the tower. The ammonia-containing steam discharged from the top of stripping tower 1 enters condenser 6, where partial condensation is achieved by controlling the cooling intensity with circulating cooling water. Utilizing the temperature difference between ammonia and water vapor (the freezing point of ammonia is -77.7℃, and the freezing point of water is 0℃), the water in the ammonia gas preferentially condenses into reflux liquid, returning to stripping tower 1 and flowing towards the bottom of the tower. This creates gas-liquid contact and a mass transfer process, while the ammonia gas remains in a gaseous state and is output, further purifying the ammonia gas. The mass transfer process is as follows: Inside the stripping tower 1, the tray or packing structure creates sufficient gas-liquid contact conditions. During the counter-current flow of rising steam and downward-flowing liquid, due to the difference in volatility between ammonia and water (ammonia boiling point -33.4℃, water boiling point 100℃), the ammonia component, due to its higher volatility, preferentially transfers from the liquid phase to the gas phase, while water, due to its higher boiling point, mainly remains in the liquid phase. This process achieves the initial separation of ammonia and water. After mass transfer, the wastewater is sent from the bottom of the stripping tower 1 to the preheater 3 to preheat the raw ammonia water, recovering heat before being discharged. The flow rate of the wastewater is controlled by the level regulating valve 7, ultimately stabilizing the liquid level in the stripping tower 1. The condensed ammonia gas is sent to the static mixer 9. The air is pressurized by the fan 10 and then enters the air heater 8 for heating. It is then mixed with ammonia gas through the static mixer 9 and finally sent to the denitrification reactor as a denitrification reducing agent.
[0026] Through the synergistic effect of each unit, the entire system achieves efficient gasification and deep dehydration of ammonia water under moderate temperature conditions. This not only overcomes the dependence of traditional processes on high-temperature flue gas, but also effectively solves the problems of equipment corrosion and catalyst pulverization caused by moisture.
[0027] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A novel ammonia-water gasification system for flue gas denitrification, characterized in that, include: The unit comprises a stripper (1), a steam supply unit, a preheater (3), an ammonia supply unit, a condenser (6), an air supply unit, and a static mixer (9). The ammonia supply unit is connected to the working fluid inlet of the preheater (3), and the working fluid outlet of the preheater (3) is connected to the ammonia inlet of the stripper (1). The steam supply unit is connected to the steam inlet of the stripper (1). The ammonia outlet at the top of the stripper (1) is connected to the inlet of the condenser (6), and the wastewater outlet at the bottom of the stripper (1) is connected to the heat medium inlet of the preheater (3). The gas outlet of the condenser (6) is connected to the static mixer (9) to transport the condensed ammonia to the static mixer (9). The liquid outlet of the condenser (6) is connected to the upper reflux liquid inlet of the stripper (1) to return the condensate to the stripper (1) for gas-liquid mass transfer. The air supply unit is connected to the static mixer (9) to mix the air and ammonia in the static mixer (9) to adjust the ammonia concentration.
2. The novel ammonia-water gasification system for flue gas denitrification according to claim 1, characterized in that, The ammonia supply unit includes an ammonia pump (5), an ammonia flow regulating valve (4), and an ammonia supply pipeline. The inlet end of the ammonia pump (5) is connected to an ammonia storage device through a pipeline, and the outlet end is connected to the working medium inlet of the preheater (3) through an ammonia supply pipeline. The ammonia supply pipeline is equipped with an ammonia flow regulating valve (4) to regulate the ammonia flow rate.
3. A novel ammonia-water gasification system for flue gas denitrification according to claim 1, characterized in that, The steam supply unit includes a steam flow regulating valve (2) and a steam supply pipeline. One end of the steam supply pipeline is connected to a steam source, and the other end is connected to the steam inlet of the stripping tower (1). The steam flow regulating valve (2) is located on the steam supply pipeline and is electrically connected to the temperature controller (TIC) on the upper part of the stripping tower (1) to control the steam flow.
4. A novel ammonia-water gasification system for flue gas denitrification according to claim 1, characterized in that, The heat medium outlet at the bottom of the preheater (3) is connected to the wastewater discharge pipe. The wastewater discharge pipe is equipped with a liquid level regulating valve (7). The liquid level regulating valve (7) is electrically connected to the liquid level controller LIC at the bottom of the stripping tower (1) to regulate the wastewater flow rate.
5. A novel ammonia-water gasification system for flue gas denitrification according to claim 1, characterized in that, The air supply unit includes a fan (10) and an air heater (8); the inlet of the fan (10) is connected to an air source, the outlet of the fan (10) is connected to the inlet of the air heater (8), and the outlet of the air heater (8) is connected to a static mixer (9).
6. A novel ammonia-water gasification system for flue gas denitrification according to claim 5, characterized in that, The heat source inlet of the air heater (8) is connected to a steam source, so that steam is used as the heat source for heating the air.