Skid-mounted ship liquid ammonia filling and ammonia gas recycling comprehensive treatment platform

Abstract

The invention discloses a skid-mounted comprehensive treatment platform for liquid ammonia filling and ammonia gas recovery of a ship. The platform comprises a liquid ammonia filling pry, an ammonia refrigeration pry, an ammonia gas recovery pry and a liquid ammonia tank car, wherein the liquid ammonia filling pry comprises a first liquid ammonia filling module, a second liquid ammonia filling module and a control module; the first liquid ammonia filling module is composed of a first pressure reducing valve, an ammonia cooler, an ammonia circulating refrigerating unit and a second pressure reducing valve; the second liquid ammonia filling module is composed of a third valve group and a first ammonia liquid pump; the input end of a first absorption tower group in the ammonia gas recovery pry is connected with a liquid ammonia tank car (or a ship fuel tank) through a fan, one path of the output end of the first absorption tower group is connected with a second absorption tower group, and one path of the output end of the second absorption tower group is connected with the bottom of an ammonia adsorption tank; the other path of the output end is connected with the ammonia gas recovery passage through a third ammonia water pump; meanwhile, the second absorption tower group is also connected with a desalted water tank through a spraying water supply pump; the technical problems that in the liquid ammonia filling process, ammonia gas is wasted, an effective ammonia gas leakage treatment system is lacked, and the ammonia gas absorption efficiency is low are solved.

Description

Technical Field

[0001] Clean fuel refueling systems and exhaust gas recovery technologies for ships, particularly involving the safe handling of liquid ammonia refueling and toxic gas treatment for ammonia-fueled ships. Background Technology

[0002] With the intensifying trend of global warming and increasingly stringent requirements for carbon emission control, the shipping industry's choice of new low-carbon or carbon-free fuels has become inevitable. Ammonia (NH3), as a carbon-free fuel, does not produce the greenhouse gas carbon dioxide when burned, and its production process is mature, making it relatively easy to store and transport, thus becoming an important development direction for the use of ammonia as fuel in ships. However, ammonia itself is toxic, and its indiscriminate discharge will have serious consequences, harming the environment and organisms.

[0003] Currently, before the initial filling of liquid ammonia storage tanks on board, nitrogen gas needs to be replaced with ammonia gas. The replacement gas contains a large amount of ammonia and needs to enter the ammonia recovery unit. Additionally, a portion of ammonia gas is released each time the tanks are filled, and this also needs to be recovered. Existing liquid ammonia refueling methods typically involve directly venting the exhaust gas from the tanker truck into the atmosphere after adsorption treatment, without effectively recovering and utilizing the ammonia, resulting in ammonia waste. Furthermore, for applications requiring strict purity standards for liquid ammonia, this method may lead to substandard purity levels. Ship fuel alternatives have evolved from LNG to ammonia fuel. Ammonia fuel is favored for its "carbon-free" and environmentally friendly properties. At atmospheric pressure, ammonia liquefaction temperature is -33.06℃, requiring minimal cooling energy, making it relatively economical and environmentally friendly. Existing liquid ammonia refueling systems require independent refrigeration, depressurization, and recovery units, which are large in size and complex to install.

[0004] In particular, nitrogen purging is required before the first filling of ship storage tanks. The purging gas and the exhaust gas contain high concentrations of ammonia (84%). Traditional direct emissions cause pollution and waste of resources. Incineration technology requires high-temperature combustion (>800℃). When treating nitrogen-containing ammonia, high concentrations of NOx are generated, requiring a denitrification system, which consumes too much energy. Ammonia recovery often uses high-pressure cryogenic methods, which consume a lot of energy and are not suitable for mobile scenarios.

[0005] Furthermore, the risk of ammonia leakage is high during the use of ammonia fuel on ships, potentially posing hazards to personnel and the environment. Existing refueling methods lack effective ammonia leakage handling systems, making it impossible to respond promptly to potential ammonia leaks and posing safety risks. Therefore, there is an urgent need for an integrated processing platform capable of liquid ammonia refueling and ammonia recovery to improve the filling efficiency and safety of shipboard liquid ammonia storage tanks.

[0006] References Several invention patents have been issued to address the issues of filling efficiency and safety of liquid ammonia storage tanks on ships. For example, CN118793927A discloses a ship ammonia leakage handling system, including a liquid ammonia storage tank, a refueling station room, a fuel preparation room, and an ammonia absorption system. This system achieves the absorption and treatment of ship ammonia through liquid ammonia refueling equipment in the refueling station room, liquid ammonia supply components in the fuel preparation room, and the ammonia absorption system. However, there is still room for optimization in the design of the ammonia absorption system, requiring further improvement in the absorption efficiency and stability of the absorption tower. CN118751024A proposes an integrated system for ammonia absorption, treatment, and reuse in ammonia-fueled ships. This system, by combining an absorption tower and an ammonia stripping tower, uses negative feedback closed-loop signal regulation from ammonia gas detector and ammonia concentration detector to dynamically adjust the absorption and desorption of ammonia solution in the ammonia storage tank under different main engine loads. However, there is still room for improvement in the design of the ammonia collection tank, requiring improvements in the selection of permeable membrane materials and structures to enhance the separation efficiency and purity of the ammonia solution.

[0007] Background technology disadvantages The existing technology has the following drawbacks: 1. Existing liquid ammonia refueling methods typically involve directly venting the exhaust gas from the tanker truck into the atmosphere after adsorption treatment, without effectively recovering and utilizing the ammonia, resulting in ammonia waste and potentially leading to substandard liquid ammonia purity; 2. Existing refueling systems lack effective ammonia leak handling systems, making it impossible to respond promptly to potential ammonia leaks, posing safety hazards and affecting ship operation safety; 3. Existing ammonia absorption systems have design limitations, with absorption efficiency and stability needing improvement, failing to meet the demands of handling large flow rates and high pressures of ammonia; 4. Existing ammonia water collection tanks are not designed reasonably, with ammonia water separation efficiency and purity needing improvement, making it difficult to meet the requirements for using high-purity liquid ammonia. Summary of the Invention

[0008] Existing technologies suffer from problems such as ammonia waste during liquid ammonia refueling, lack of effective ammonia leakage handling systems, and low ammonia absorption efficiency. Therefore, to address these issues, this invention provides a skid-mounted integrated platform for liquid ammonia refueling and recovery on ships.

[0009] This invention is achieved using the following technical solution: A skid-mounted integrated platform for liquid ammonia filling and recovery on a ship, the platform comprising a liquid ammonia filling skid, an ammonia refrigeration skid, an ammonia recovery skid, and a liquid ammonia tanker; wherein: The liquid ammonia filling skid includes a first liquid ammonia filling module, a second liquid ammonia filling module, and a control module; the first liquid ammonia filling module consists of a first pressure reducing valve, an ammonia cooler, an ammonia circulation refrigeration unit, and a second pressure reducing valve; the second liquid ammonia filling module consists of a third valve group and a first ammonia pump; wherein: The control module selects the liquid ammonia filling module according to the liquid ammonia state of the liquid ammonia tanker; when the liquid ammonia pressure is between 0.4 MPaG and 2.0 MPaG, the control module starts the first liquid ammonia filling module, wherein: the ammonia circulation refrigeration unit and the ammonia cooler cool the liquid ammonia to -9 to -30℃; when the liquid ammonia state is low temperature and low pressure, the second liquid ammonia filling module is started, wherein: the ammonia pump pressurizes the liquid ammonia to 0.1 to 0.3 MPaG and injects it into the ship's liquid ammonia storage tank; The ammonia recovery skid includes a first absorption tower group, a second absorption tower group, a fan, an ammonia water cooler, a second ammonia water pump, a third ammonia water pump, a spray water supply pump, an ammonia adsorption tank, and a demineralized water tank. The input end of the first absorption tower group is connected to a liquid ammonia tanker (or a ship fuel tank) via the fan. One output end of the first absorption tower group is connected to the second absorption tower group, and the other output end of the first absorption tower group is connected to an ammonia water transport device via the second ammonia water pump. The output end of the second ammonia water pump is connected to the first absorption tower group via the ammonia water cooler to form an ammonia recovery path. One output end of the second absorption tower group is connected to the bottom of the ammonia adsorption tank. The other output end of the second absorption tower group is connected to the ammonia recovery path via the third ammonia water pump. Simultaneously, the second absorption tower group is also connected to the demineralized water tank via the spray water supply pump.

[0010] Furthermore, the ammonia cooler adopts a plate heat exchanger or a tube bundle heat exchanger; the ammonia cycle refrigeration unit X-101 adopts a variable frequency screw compressor or a scroll compressor, with a cooling capacity of 2000KW and a power consumption of 1000kW; the first pressure reducing valve and the second pressure reducing valve of the first liquid ammonia filling module adopt a manual regulating valve or an electric regulating valve, with downstream pressures of 0.3MPaG and 0.2MPaG, respectively.

[0011] Furthermore, the first and second absorption tower groups adopt plate tower or packed tower structures, and the towers employ a single or combined process of water washing and acid washing; wherein: the acid washing solution uses ammonium bicarbonate (NH4HCO3), ammonium sulfate ((NH4)2SO4), ammonium chloride (NH4Cl), oxalic acid (H2C2O4), acetic acid (CH3COOH), citric acid (C6H8O7), phosphoric acid (H3PO4) or carbonic acid (H2CO3), with a concentration of 10~30%.

[0012] Furthermore, both the first and second absorption tower groups employ water washing towers. The ammonia recovery unit operates as follows: Exhaust gas from the ship's fuel tank is pumped to the ammonia recovery skid by a blower into the first water washing tower, where it undergoes full contact with the ammonia solution for mass and heat transfer. Unabsorbed gas flows out from the top of the tower, while the bottom contains a highly concentrated ammonia solution. This solution is pressurized by a second ammonia pump, passes through an ammonia cooler, and returns to the top to absorb ammonia. If the ammonia concentration at the bottom of the tower meets the standard, it can be collected from another bypass at the outlet of the second ammonia pump and transported externally. The gas flowing out from the top of the first water scrubbing tower enters the bottom of the second water scrubbing tower for further ammonia absorption. The absorbent in the second water scrubbing tower is demineralized water supplied by a spray water supply pump. After absorption, the ammonia water at the bottom of the second water scrubbing tower is pumped back to the top of the first water scrubbing tower by a third ammonia water pump. The tail gas flowing out from the top of the second absorption tower may not meet the ammonia content under high absorption load conditions, so it is further absorbed by an ammonia adsorption tank to ensure that it meets the emission standards.

[0013] Furthermore, the ammonia adsorption tank uses activated carbon, molecular sieve, calcium phosphate, or calcium silicate as adsorbents.

[0014] Beneficial effects Compared with the prior art, the present invention can achieve the following beneficial technical effects: 1. This invention achieves precise control of liquid ammonia filling by setting up a first liquid ammonia filling module and a second liquid ammonia filling module, and selecting the appropriate filling module according to the pressure state of the liquid ammonia, thereby improving filling efficiency and filling quality of the liquid ammonia storage tank; 2. This invention employs a combination design of an ammonia circulation refrigeration unit and an ammonia cooler to effectively control the liquid ammonia temperature between -9 and -30°C, ensuring the purity of the liquid ammonia and avoiding ammonia contamination caused by improper temperature control. 3. This invention achieves efficient recovery and utilization of ammonia through a multi-stage ammonia absorption and treatment system, including a first absorption tower group, a second absorption tower group, and an ammonia adsorption tank, avoiding waste caused by direct ammonia emission and reducing operating costs. 4. This invention adopts a multi-stage ammonia absorption design. By optimizing the structure and operating parameters of the absorption tower, the absorption efficiency and processing capacity of ammonia are improved, ensuring the stable operation of the system under high flow and high pressure conditions. 5. This invention features a dedicated ammonia water cooler and ammonia water pump system. By recycling ammonia water, the overall efficiency of the system is improved, energy consumption is reduced, and maintenance costs are decreased. 6. The present invention, through the design of the spray water supply pump and the demineralized water tank, provides a guarantee for the stable operation of the system, effectively prevents the accumulation of ammonia inside the system, and improves the safety and reliability of the system; 7. This invention supports parallel operation of multiple unloading positions, which improves production efficiency, reduces filling time, and lowers operating costs. At the same time, it enables the immediate production and transportation of ammonia water, avoiding the safety hazards of on-site storage. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the integrated processing platform structure for skid-mounted ship liquid ammonia filling and ammonia recovery according to the present invention; Figure 2 This is a schematic diagram of the liquid ammonia filling skid structure in a skid-mounted integrated treatment platform for liquid ammonia filling and recovery on a ship, according to the present invention. Figure 3 This is a schematic diagram of the ammonia recovery skid structure in a skid-mounted integrated treatment platform for liquid ammonia filling and recovery on a ship, according to the present invention. Figure Labels E-101: Ammonia cooler; X-101: Ammonia cycle refrigeration unit; P-101: First ammonia water pump; T-201: First absorption tower group; T-202: Second absorption tower group; C-201: Fan; E-201: Ammonia water cooler; P-201: Second ammonia water pump; P-202: Third ammonia water pump; P-203: Spray water supply pump; V-202: Ammonia adsorption tank; V-201: Demineralized water tank; Detailed Implementation

[0016] The following will be combined with the appendix Figure 1 - Appendix Figure 3 The technical solution of the present invention will be described in detail below.

[0017] like Figure 1 As shown, this invention provides a skid-mounted integrated platform for liquid ammonia refueling and recovery on ships; the platform includes a liquid ammonia refueling skid, an ammonia refrigeration skid, an ammonia recovery skid, and a liquid ammonia tanker; wherein: The liquid ammonia filling skid includes a first liquid ammonia filling module, a second liquid ammonia filling module, and a control module; the first liquid ammonia filling module consists of a first pressure reducing valve, an ammonia cooler E-101, an ammonia circulation refrigeration unit X-101, and a second pressure reducing valve; the second liquid ammonia filling module consists of a third valve group and an ammonia pump P-101, as shown below. Figure 2 As shown: The control module selects the liquid ammonia filling module based on the state of the liquid ammonia delivered by the tanker. If the pressure of the liquid ammonia is between 0.4 MPaG and 2.0 MPaG, the control module activates the first liquid ammonia filling module, wherein the ammonia circulation refrigeration unit and the ammonia cooler E-101 cool the liquid ammonia to -9 to -30°C; and the first and second pressure reducing valves lower the liquid ammonia to 0.2 to 0.3 MPaG before injecting it into the ship's liquid ammonia storage tank. If the liquid ammonia is in a low-temperature and low-pressure state, the second liquid ammonia filling module is activated, wherein the ammonia pump pressurizes the liquid ammonia to 0.1 to 0.3 MPaG before injecting it into the ship's liquid ammonia storage tank. In practice, the liquid ammonia filling unit cools the liquid ammonia from room temperature to -18°C via the cooler E-101, and then lowers it to 0.2 MPaG via the pressure reducing valve before injecting it into the ship's liquid ammonia storage tank. The ammonia circulation refrigeration unit X-101 provides the cold source. The refrigeration unit X-101 includes a refrigerant, a refrigerant compressor, a condenser, and an evaporator; the refrigerant is ammonia, R22, R23, R404A, R14, ethanol, propane, ethylene, ethane, etc., with ammonia being preferred, and the refrigerant is recycled.

[0018] Meanwhile, before the ship's liquid ammonia storage tank is filled with liquid ammonia for the first time, nitrogen needs to be replaced with ammonia gas. The replacement gas contains a large amount of ammonia and needs to enter the ammonia recovery unit. In addition, a portion of ammonia gas is released each time the ship's liquid ammonia storage tank is filled with liquid ammonia, which also needs to be recovered. Therefore, an ammonia recovery unit is set up. Furthermore, in the event of an accident, a large amount of ammonia released can also enter the ammonia recovery device.

[0019] like Figure 3As shown, the ammonia recovery skid includes a first absorption tower group T-201, a second absorption tower group T-202, a blower C-201; an E-20 ammonia water cooler; a first ammonia water pump P-201, a second ammonia water pump P-202; a spray water supply pump P-203; an ammonia adsorption tank V-202; and a demineralized water tank V-201. The input end of the first absorption tower group T-201 is connected to a liquid ammonia tanker (or ship fuel tank) via blower C-201; the output end of the first absorption tower group T-201 is connected to the second absorption tower group T-202. The first absorption tower group T-202 is connected; another output end of the first absorption tower group T-201 is connected to the ammonia water transportation device through the second ammonia water pump P-201; at the same time, the output end of the second ammonia water pump P-201 is also connected to the first absorption tower group T201 through the ammonia water cooler E-201 to form an ammonia recovery passage; the first absorption tower group and the second absorption tower group of the present invention are composed of a water washing tower, an acid washing tower, a stripping tower, or a combination thereof; the water washing tower, acid washing tower, and stripping tower can all adopt plate tower and packed tower structures. Among them, the acid washing solution used in the acid washing tower is a weak acid substance, including but not limited to ammonium bicarbonate (NH4HCO3), ammonium sulfate ((NH4)2SO4), ammonium chloride (NH4Cl), oxalic acid (H2C2O4), acetic acid (CH3COOH), citric acid (C6H8O7), phosphoric acid (H3PO4), and carbonic acid (H2CO3). The desorption tower uses a bottom reboiler for heating and desorption. The reboiler can be a kettle-type reboiler or a shell-and-tube heat exchanger. The ammonium acid solution is heated to 100~300℃ in the reboiler. The spray pump P-203 is a reciprocating pump or a centrifugal pump. One output of the second absorption tower group T-202 is connected to the bottom of the ammonia adsorption tank V-202; the other output is connected to the ammonia recovery passage via the second ammonia water pump P-202; simultaneously, the second absorption tower group is also connected to the demineralized water tank via a spray water supply pump p-203; the first absorption tower group T-201 and the second absorption tower group T-202 of this invention are constructed using water washing towers, acid washing towers, or a combination thereof. The ammonia adsorption tank V-202 serves as the final process to ensure that the ammonia content in the exhaust gas meets emission standards, and the adsorbent used is activated carbon, molecular sieve, calcium phosphate, or calcium silicate.

[0020] The working process of the ammonia recovery skid in this invention: The exhaust gas from the ship's fuel tank is sent to the ammonia recovery unit. First, the gas is pumped into the first water washing tower (T-201) by the C-201 blower. The ammonia gas and ammonia solution are fully in contact for mass and heat transfer. The unabsorbed gas flows out from the top of the first absorption tower group. The bottom of the tower contains ammonia solution with a higher concentration. It is pressurized by the P-201 ammonia water pump and returned to the top of the tower to absorb ammonia gas after passing through the E-201 ammonia water cooler. If the ammonia concentration at the bottom of the tower reaches 20%, it can be extracted from another bypass at the output end of the P-201 ammonia water pump and transported off-site.

[0021] The gas flowing from the top of the first absorption tower T-201 enters the bottom of the second absorption tower T-202 for further absorption of ammonia. The absorbent in the second absorption tower T-202 is demineralized water supplied by the P-203 spray water pump. After absorption, the ammonia water at the bottom of the tower is pumped back to the top of the first water washing tower T-201 by the P-202 ammonia water pump. The tail gas flowing from the top of the second absorption tower T-202 may not meet the ammonia content standard under high absorption load conditions, so it is further absorbed by the V-202 ammonia adsorption tank to ensure that it meets the emission standards.

[0022] Example 1: This invention provides a skid-mounted integrated platform for liquid ammonia refueling and recovery on ships, including a liquid ammonia refueling skid, an ammonia refrigeration skid, an ammonia recovery skid, and a liquid ammonia tanker. The liquid ammonia refueling skid includes a first liquid ammonia refueling module, a second liquid ammonia refueling module, and a control module. The first liquid ammonia refueling module consists of a first pressure reducing valve, an ammonia cooler E-101, an ammonia cycle refrigeration unit X-101, and a second pressure reducing valve. The first and second pressure reducing valves are manually adjustable, with downstream pressures of 0.3 MPaG and 0.1 MPaG, respectively. The ammonia cooler E-101 uses a plate heat exchanger with a heat exchange area of ​​60 m², and the coolant is ammonia gas, which is recycled. The ammonia cycle refrigeration unit X-101 uses a variable frequency screw compressor with a cooling capacity of 2000 kW and a power consumption of 1000 kW. The second liquid ammonia refueling module consists of a third valve group and an ammonia pump P-101. The ammonia pump P-101 is a centrifugal pump with a flow rate of 20 m³ / h. Wherein: The control module selects the first liquid ammonia injection module based on the liquid ammonia pressure of 1.5 MPaG delivered by the tanker. The liquid ammonia is cooled to -20°C by the ammonia circulation refrigeration unit X-101 and the ammonia cooler E-101, and then adjusted to 0.3 MPaG and 0.1 MPaG respectively by the first and second pressure reducing valves before being injected into the ship's liquid ammonia storage tank. The ammonia recovery unit includes a first absorption tower group, a second absorption tower group, a blower C-201, an ammonia water cooler E-201, an ammonia water pump P-201 / 202, a spray water supply pump P-203, an ammonia adsorption tank V-202, and a demineralized water tank V-201. The first absorption tower group T-201 is a plate tower with a water washing process inside. The second absorption tower group T-202 is a plate tower with an acid washing process inside, using a 20% ammonium bicarbonate solution as the acid washing solution. The input end of the first absorption tower group T-201 is connected to a liquid ammonia tanker truck via a blower C-201. One output end is connected to the second absorption tower group, and the other is connected to the ammonia water transport device via an ammonia water pump P-201. The output end of the ammonia water pump P-201 is connected to the first absorption tower group T-201 via an ammonia water cooler E-201, forming an ammonia recovery path. One output end of the second absorption tower group T-202 is connected to the bottom of the ammonia adsorption tank V-202, and the other is connected to the ammonia recovery path via the ammonia water pump P-202. The ammonia adsorption tank V-202 uses activated carbon as the adsorbent. The demineralized water tank V-201 has a volume of 15 m³ and is made of fiberglass. The working process of this invention is as follows: Liquid ammonia enters the first absorption tower group T-201 via blower C-201, where it fully contacts the ammonia solution for mass and heat transfer. Unabsorbed gas flows out from the top of the tower, while the ammonia solution with a higher concentration at the bottom is pressurized by pump P-201, passes through cooler E-201, and returns to the top for further absorption. When the ammonia concentration at the bottom reaches 20%, it can be extracted and transported externally through another branch of P-201. The gas flowing out from the top of the first absorption tower T-201 enters the bottom of the second absorption tower T-202 for further absorption. The absorbent in the second absorption tower T-202 is demineralized water supplied by spray pump P-203. After absorption, the ammonia solution at the bottom of the tower is pumped into the top of the first water washing tower T-201 by ammonia pump P-202. The tail gas flowing out from the top of the second absorption tower T-202 is further absorbed and treated by ammonia adsorption tank V-202 before being discharged in compliance with standards.

[0023] Example 2: This invention provides a skid-mounted integrated platform for liquid ammonia refueling and recovery on ships, including a liquid ammonia refueling skid, an ammonia refrigeration skid, an ammonia recovery skid, and a liquid ammonia tanker. The liquid ammonia refueling skid includes a first liquid ammonia refueling module, a second liquid ammonia refueling module, and a control module. The first liquid ammonia refueling module consists of a first pressure reducing valve, an ammonia cooler E-101, an ammonia cycle refrigeration unit X-101, and a second pressure reducing valve. The first and second pressure reducing valves are electrically adjustable valves, with downstream pressures of 0.4 MPaG and 0.2 MPaG, respectively. The ammonia cooler E-101 uses a tube bundle heat exchanger with a heat exchange area of ​​50 m², and uses R22 as the coolant, which is recycled. The ammonia cycle refrigeration unit X-101 uses a scroll compressor with a cooling capacity of 2000 kW and a power consumption of 1000 kW. The second liquid ammonia refueling module consists of a third valve group and an ammonia pump P-101. The ammonia pump P-101 is a reciprocating pump with a flow rate of 25 m³ / h. Wherein: The control module selects the first liquid ammonia injection module based on the liquid ammonia pressure of 1.30 MPaG delivered by the tanker truck. The liquid ammonia is cooled to -25°C by the ammonia circulation refrigeration unit X-101 and the ammonia cooler E-101, and then adjusted to 0.4 MPaG and 0.2 MPaG respectively by the first and second pressure reducing valves before being injected into the ship's liquid ammonia storage tank. The ammonia recovery unit includes a first absorption tower group, a second absorption tower group fan C-201, an ammonia water cooler E-201, an ammonia water pump P-201 / 202, a spray water supply pump P-203, an ammonia adsorption tank V-202, and a demineralized water tank V-201. The first absorption tower group T-201 is a packed tower, employing a combination of water washing and acid washing processes. The second absorption tower group T-202 is a packed tower, employing a desorption process with a desorption temperature of 150°C. The input end of the first absorption tower group T-201 is connected to a liquid ammonia tanker truck via a blower C-201. One output end is connected to the second absorption tower group, and the other is connected to the ammonia water transport device via an ammonia water pump P-201. The output end of the ammonia water pump P-201 is connected to the first absorption tower group T201 via an ammonia water cooler E-201, forming an ammonia recovery path. One output end of the second absorption tower group T-202 is connected to the bottom of the ammonia adsorption tank V-202, and the other is connected to the ammonia recovery path via the ammonia water pump P-202. The ammonia adsorption tank V-202 uses molecular sieves as the adsorbent. The demineralized water tank V-201 has a volume of 18 m³ and is made of fiberglass.

[0024] The working process of this invention is as follows: Liquid ammonia enters the first absorption tower group T-201 via blower C-201, where it fully contacts the ammonia solution for mass and heat transfer. Unabsorbed gas flows out from the top of the tower, while the ammonia solution with a higher concentration at the bottom is pressurized by pump P-201, passes through cooler E-201, and returns to the top for further absorption. When the ammonia concentration at the bottom reaches 20%, it can be extracted and transported externally through another branch of P-201. The gas flowing out from the top of the first absorption tower T-201 enters the bottom of the second absorption tower T-202 for further absorption. The absorbent in the second absorption tower T-202 is demineralized water supplied by spray pump P-203. After absorption, the ammonia solution at the bottom of the tower is pumped into the top of the first water washing tower T-201 by ammonia pump P-202. The tail gas flowing out from the top of the second absorption tower T-202 is further absorbed and treated by ammonia adsorption tank V-202 before being discharged in compliance with standards.

[0025] Although the present invention has been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all protected by the present invention.

Claims

1. A skid-mounted integrated treatment platform for liquid ammonia filling and ammonia recovery on ships, characterized in that: The platform includes a liquid ammonia filling skid, an ammonia refrigeration skid, an ammonia recovery skid, and a liquid ammonia tanker truck; wherein: The liquid ammonia filling skid includes a first liquid ammonia filling module, a second liquid ammonia filling module, and a control module; the first liquid ammonia filling module consists of a first pressure reducing valve, an ammonia cooler, an ammonia circulation refrigeration unit, and a second pressure reducing valve; the second liquid ammonia filling module consists of a third valve group and a first ammonia liquid pump P-101; wherein: The control module selects the liquid ammonia filling module based on the liquid ammonia status of the liquid ammonia tanker. When the liquid ammonia pressure is between 0.4 MPaG and 2.0 MPaG, the control module starts the first liquid ammonia filling module, wherein the ammonia circulation refrigeration unit and the ammonia cooler cool the liquid ammonia to -9 to -30°C. When the liquid ammonia is in a low temperature and low pressure state, the second liquid ammonia filling module is started, wherein the ammonia pump pressurizes the liquid ammonia to 0.1 to 0.3 MPaG and injects it into the ship's liquid ammonia storage tank. The ammonia recovery skid includes a first absorption tower group, a second absorption tower group, a fan, an ammonia water cooler, a second ammonia water pump, a third ammonia water pump, a spray water supply pump, an ammonia adsorption tank, and a demineralized water tank. The input end of the first absorption tower group is connected to the ammonia output equipment via the fan. One output end of the first absorption tower group is connected to the second absorption tower group, and the other output end of the first absorption tower group is connected to the ammonia water external transportation device via the second ammonia water pump. The output end of the second ammonia water pump is connected to the first absorption tower group via the ammonia water cooler to form an ammonia recovery path. One output end of the second absorption tower group is connected to the bottom of the ammonia adsorption tank. The other output end of the second absorption tower group is connected to the ammonia recovery path via the third ammonia water pump. Simultaneously, the second absorption tower group is also connected to the demineralized water tank via the spray water supply pump.

2. The skid-mounted integrated treatment platform for marine liquid ammonia refueling and ammonia recovery according to claim 1, characterized in that: The ammonia cooler E-101 uses a plate heat exchanger or a tube bundle heat exchanger; the ammonia cycle refrigeration unit X-101 uses a variable frequency screw compressor or a scroll compressor, with a cooling capacity of 2000KW and a power consumption of 1000kW; the first and second pressure reducing valves of the first liquid ammonia filling module are manual or electric regulating valves, with downstream pressures of 0.3MPaG and 0.2MPaG, respectively.

3. The skid-mounted integrated treatment platform for marine liquid ammonia refueling and ammonia recovery according to claim 1, characterized in that: The first absorption tower group T-201 and the second absorption tower group T-202 adopt plate tower or packed tower structure, and use a single process or a combination of water washing and acid washing in the tower; wherein: the acid washing solution uses ammonium bicarbonate (NH4HCO3), ammonium sulfate ((NH4)2SO4), ammonium chloride (NH4Cl), oxalic acid (H2C2O4), acetic acid (CH3COOH), citric acid (C6H8O7), phosphoric acid (H3PO4) or carbonic acid (H2CO3), with a concentration of 10~30%.

4. The skid-mounted integrated treatment platform for marine liquid ammonia refueling and ammonia recovery according to claim 1, characterized in that: Both the first absorption tower group T-201 and the second absorption tower group T-202 are water washing towers. The ammonia recovery unit operates as follows: Exhaust gas from the ship's fuel tank is pumped to the ammonia recovery skid by a blower and then into the first water washing tower. The gas undergoes full contact with the ammonia solution for mass and heat transfer. Unabsorbed gas flows out from the top of the tower, while the bottom contains a highly concentrated ammonia solution. This solution is pressurized by a second ammonia pump, passes through an ammonia cooler, and returns to the top of the tower to absorb ammonia. If the ammonia concentration at the bottom of the tower meets the standard, it can be collected from another bypass at the outlet of the second ammonia pump and transported externally. The gas flowing out from the top of the first water scrubbing tower enters the bottom of the second water scrubbing tower for further ammonia absorption. The absorbent in the second water scrubbing tower is demineralized water supplied by a spray water supply pump. After absorption, the ammonia water at the bottom of the second water scrubbing tower is pumped back to the top of the first water scrubbing tower by a third ammonia water pump. The tail gas flowing out from the top of the second absorption tower may not meet the ammonia content under high absorption load conditions, so it is further absorbed by an ammonia adsorption tank to ensure that it meets the emission standards.

5. A skid-mounted integrated treatment platform for marine liquid ammonia filling and ammonia recovery according to any one of claims 1-4, characterized in that: The ammonia adsorption tank V-202 uses activated carbon, molecular sieve, calcium phosphate, or calcium silicate as adsorbents.

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