Ammonia water preparation and ammonia gas absorption device and method and application

Abstract

The invention provides an ammonia water preparation and ammonia gas absorption device and method and application. The device comprises an ammonia water container, and the ammonia water container internally comprises a raw material mixing storage area, an ammonia water feeding area and an ammonia gas absorption area; the raw material mixing and storing area and the ammonia water feeding area are respectively arranged on the left side and the right side of the bottom area of the container and are separated by a lower partition plate; the ammonia gas absorption area is arranged at the top area of the ammonia water container and is separated from the raw material mixing and storing area and the ammonia water feeding area through an upper partition plate, and a communicating pipe which is communicated with the ammonia water absorption area upwards is arranged on the upper partition plate. The device provided by the invention can provide ammonia water with stable preparation and different concentrations so as to meet the adjusting requirement of the pH value of an epoxidation reactor system.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical product synthesis, and more particularly to a device and method for preparing ammonia water and absorbing ammonia gas, and applications thereof. Background Art

[0002] Propylene oxide is a very important raw material for organic synthesis and is the third largest propylene derivative after polypropylene and acrylonitrile.

[0003] At present, the main processes for producing propylene oxide are the chlorohydrin process and the co-oxidation process. The chlorohydrin process is simple, but it will produce a lot of wastewater and waste residue, which is not friendly to the environment; the co-oxidation process is simple, mild, has good product selectivity, is environmentally friendly, and has high atomic utilization, making it a better choice for preparing propylene oxide.

[0004] In the process of preparing propylene oxide by the co-oxidation method, propylene and hydrogen peroxide are used as raw materials to react in an oxidation reactor to directly generate propylene oxide. This process is not only simple but also environmentally friendly. However, the reaction system needs to be carried out in a weak alkaline environment for better results. Generally, ammonia water is introduced into the system to maintain the weak alkaline environment of the reaction system.

[0005] Ammonia is an important inorganic compound. Ammonia dissolved in water generates ammonia monohydrate which can ionize hydroxide ions and is weakly alkaline. It is a weak base commonly used to adjust pH in the chemical industry. Ammonia has a large solubility in water. At room temperature and pressure, 700 volumes of ammonia can be dissolved in one volume of water. However, a large amount of heat is released during the mixing of ammonia and water, and ammonia is unstable when dissolved in water and can easily evaporate from the ammonia water. Therefore, providing a stable reaction system for preparing propylene oxide from propylene and hydrogen peroxide and ammonia water of suitable concentration is an urgent problem to be solved. Summary of the invention

[0006] To solve the above problems, the present invention provides a device and method for preparing ammonia water and absorbing ammonia gas, wherein the device can prepare ammonia water of stable and appropriate concentration to provide to a downstream reactor for adjusting the pH value of the reaction system.

[0007] Firstly, one of the purposes of the present invention is to provide a device for preparing ammonia water and absorbing ammonia gas.

[0008] Specifically, the device includes an ammonia water container, which has a double-layer structure, including a raw material mixing storage area, an ammonia water feeding area and an ammonia absorption area, wherein the raw material mixing storage area and the ammonia water feeding area are respectively arranged on the left and right sides of the bottom area of ​​the container, and are separated by a lower partition; the ammonia absorption area is arranged in the top area of ​​the ammonia water container, and is separated from the raw material mixing storage area and the ammonia water feeding area by an upper partition, and a connecting pipe is provided on the upper partition, which leads upward into the ammonia water absorption area and connects the raw material mixing storage area and the ammonia water feeding area.

[0009] The present invention mixes ammonia gas and desalted water into an ammonia solution of a predetermined concentration through a raw material mixing and storage area, and receives and stores the ammonia solution in the raw material mixing and storage area through an ammonia feeding area. The ammonia solution in the raw material mixing and storage area overflows into the ammonia feeding area through the top of the lower partition plate to be received and stored, so as to wait for the prepared ammonia solution to be applied to the reaction system of the downstream reactor. Ammonia volatilization will occur in the ammonia solution in the raw material mixing and storage area and the ammonia feeding area. The present invention arranges an ammonia absorption area on the upper part of the raw material mixing and storage area and the ammonia feeding area, and the volatilized ammonia can enter the ammonia absorption area through a connecting pipe on the upper partition plate, and be absorbed again by the desalted water in the ammonia absorption area for reuse, thereby improving the utilization rate of ammonia, saving costs, and preventing the volatilized ammonia from entering the air and polluting the environment.

[0010] The present invention provides a simple and practical device for preparing ammonia water, which can realize the multiple functions of preparing, storing and absorbing ammonia gas for recycling, and can timely provide ammonia water with suitable concentration to meet the application needs of downstream areas, and can also ensure the stability of the concentration of ammonia water solution during application.

[0011] Further, an ammonia inlet and a first desalted water inlet are respectively provided on the side wall of the ammonia container in the raw material mixing storage area, the ammonia inlet is connected to the ammonia source through an ammonia delivery pipe, and the first desalted water inlet is connected to the desalted water source through the first desalted water delivery pipe. Preferably, the ammonia inlet of the present invention is arranged at a position higher than the top of the lower partition plate on the side wall of the ammonia container, and is connected to a horizontal pipe through an "L"-shaped pipe, the horizontal pipe is arranged at the bottom of the raw material mixing storage area, and a number of small holes are evenly distributed on the horizontal pipe, and the first desalted water inlet is arranged at the upper part of the horizontal pipe, thereby ammonia can enter the desalted water in a dispersed manner through the holes dispersed on the horizontal pipe, on the one hand, it is ensured that ammonia can fully contact with the desalted water flowing downward, so that ammonia is fully dissolved therein; on the other hand, a large amount of heat will be released when ammonia and desalted water are mixed, so that the heat is quickly dispersed, avoiding local temperature overheating; on the other hand, the ammonia inlet position is higher than the highest point of the lower partition plate, preventing ammonia from backflowing into the ammonia delivery pipeline.

[0012] Furthermore, a cooling device is provided outside the ammonia water container, and the cooling device is provided with a chilled water inlet and a chilled water outlet, the chilled water inlet is provided at the bottom of the cooling device, and the chilled water outlet is provided at the top of the cooling device. The present invention transfers the heat released by the ammonia gas dissolved in water through the cooling device, thereby ensuring the stability of the temperature of the raw material mixing storage area. Preferably, the cooling device of the present invention is a chilled water coil provided outside the container.

[0013] Furthermore, the ammonia absorption zone is provided with a second desalted water inlet, an absorption liquid outlet, a nitrogen inlet and an exhaust port, wherein the second desalted water inlet is connected to a second desalted water source through a second desalted water delivery pipe, and is used to replenish desalted water into the ammonia absorption zone for absorbing ammonia volatilized from the raw material mixing storage zone and the ammonia feeding zone; the absorption liquid outlet is connected to the first desalted water delivery pipe through an absorption liquid output pipe, that is, when the ammonia aqueous solution in the ammonia absorption zone reaches a certain concentration, the absorption liquid can be returned to the first desalted water delivery pipe through the absorption liquid output pipe to be returned to the raw material mixing storage zone, so that the ammonia can be fully utilized again, thereby avoiding the loss of ammonia or volatilization into the air; the nitrogen inlet is connected to the nitrogen source through a nitrogen delivery pipe, and a nitrogen control valve is provided on the nitrogen delivery pipe. The present invention adjusts the pressure in the ammonia container by delivering nitrogen into the container, thereby adjusting the concentration of the prepared ammonia; the exhaust port is connected to the waste liquid treatment zone through an exhaust delivery pipe, and an exhaust control valve is provided on the exhaust delivery pipe to control the exhaust rate.

[0014] Furthermore, an ammonia mixer is provided on the first desalted water delivery pipe, and a circulating chilled water jacket is provided on the outside of the ammonia mixer. Preferably, the ammonia delivery pipeline is divided into two routes, one route is connected to the ammonia inlet and is provided with a first shut-off valve, and the other route is connected to the ammonia mixer and is provided with a second shut-off valve. It is worth mentioning that when a higher concentration of ammonia solution is required, the input path of ammonia needs to be changed. That is, the first shut-off valve on the ammonia delivery pipe is closed first, and the input amount of nitrogen is adjusted by the nitrogen control valve to increase the pressure of the raw material mixing storage area, and the second shut-off valve on the ammonia delivery pipe leading to the ammonia mixer is opened. Ammonia is first sent to the ammonia mixer to mix with desalted water, and then sent to the raw material mixing storage area. The ammonia mixer can quickly mix ammonia and desalted water, and at the same time, the chilled water jacket outside the ammonia mixer ensures that the heat released by the ammonia dissolving in water can be quickly taken away, ensuring a larger amount of ammonia dissolved. At the same time, increasing the pressure of the ammonia container can also increase the concentration of ammonia.

[0015] Furthermore, an ammonia outlet is provided at the bottom of the ammonia feed zone, and the ammonia outlet is connected to the downstream reactor through an ammonia delivery pipe. The ammonia delivery pipe is provided with a metering pump for controlling the flow rate of the ammonia solution to the downstream reactor. The flow rate of the metering pump can be adjusted according to actual needs to adjust the pH value of the reaction system in the downstream reactor.

[0016] Furthermore, a bypass pipeline connected to the ammonia delivery pipe is arranged at the bottom of the ammonia mixing and storage area of ​​the present invention. When the upstream ammonia gas supply is suspended, the bypass valve at the bottom of the ammonia mixing and storage area is opened to deliver the ammonia in the ammonia mixing and storage area to the downstream reactor. The ammonia mixing and storage area also performs the function of storing ammonia solution.

[0017] Preferably, the downstream reactor can be an epoxidation reactor, which includes a feed mixer and a reactor, the feed mixer is connected to the raw material source through a raw material delivery pipe, and is connected to the ammonia feeding zone through an ammonia delivery pipe, that is, the raw material and ammonia are mixed in the feed mixer, and the flow rate of the ammonia solution entering the feed mixer is controlled by a metering pump provided on the ammonia delivery pipe. After adjusting the pH value of the system, the mixed raw materials in the feed mixer are sent to the reactor through the feed pipe for reaction, and the materials reacted in the reactor are sent out through the material output pipe. The device of the present invention can continuously and stably provide a stable concentration of ammonia solution to the epoxidation reactor to meet the requirement of maintaining a suitable pH of the reaction system.

[0018] Secondly, the second object of the present invention is to provide a method for preparing ammonia water and absorbing ammonia gas.

[0019] Specifically, the method is implemented by an ammonia water preparation and ammonia gas absorption device which is one of the purposes of the present invention, wherein the method comprises the following steps: transporting ammonia gas and desalted water to a raw material mixing storage area, opening a nitrogen control valve to allow the raw material mixing storage area to reach a predetermined pressure; opening a cooling device to allow the raw material mixing storage area to maintain a predetermined temperature; the fully mixed ammonia solution overflows to an ammonia water feeding area through a lower baffle, and a metering pump is opened to transport the ammonia water in the ammonia water feeding area to a downstream reactor; and the volatilized ammonia gas is absorbed in the ammonia gas absorption area.

[0020] Preferably, in the present invention, the path for conveying ammonia gas to the raw material mixing storage area can be adjusted by controlling the first shut-off valve and the second shut-off valve.

[0021] Preferably, the mass ratio of the feed of ammonia gas and desalted water is controlled to be 1 / 8 to 1 / 2.

[0022] Preferably, the pressure in the raw material mixing and storage area is controlled to be 0.1-0.9 MPaG.

[0023] Preferably, the temperature of the raw material mixing and storage area is controlled at 20-35°C.

[0024] Preferably, the concentration of the aqueous ammonia solution in the aqueous ammonia feed zone is 10 to 35%.

[0025] Again, the third object of the present invention is to provide the application of the device for preparing ammonia water and absorbing ammonia gas which is one of the objects of the present invention.

[0026] That is, the ammonia solution prepared by the ammonia solution preparation and ammonia gas absorption device, which is one of the purposes of the present invention, is used to adjust the pH value of the downstream reaction system; preferably, the downstream reaction system is a reaction system in which propylene and hydrogen peroxide are used as raw materials to react in an epoxidation reactor to generate propylene oxide.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The system for adjusting the concentration of ammonia water preparation, ammonia absorption and downstream pH value adjustment provided by the present invention has a simple process, good safety, high efficiency and small space occupation, and can conveniently prepare ammonia water solutions of different stable concentrations to meet the demand for adjusting the downstream pH value; at the same time, the system of the present invention has high ammonia utilization efficiency, saves costs and avoids environmental pollution through the recycling of ammonia. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a process flow chart of the device for preparing ammonia water and absorbing ammonia gas provided in Example 1 of the present invention.

[0030] Figure 2 This is a process flow chart of the device for preparing ammonia water and absorbing ammonia gas provided in Example 2 of the present invention.

[0031] Description of reference numerals:

[0032] 10. Raw material mixing storage area; 11. First desalted water inlet; 111. First desalted water delivery pipe; 112. First desalted water source; 12. Ammonia inlet; 121. Ammonia delivery pipe; 122. Horizontal pipe; 123. Ammonia source; 124. Hole; 125. First shut-off valve; 126. Second shut-off valve; 127. Bypass pipeline; 128. Bypass valve; 20. Ammonia absorption area; 21. Second desalted water inlet; 211. Second desalted water delivery pipe; 212. Second desalted water source; 22. Absorption liquid outlet; 221. Absorption liquid output pipe; 23. Nitrogen inlet; 231. Nitrogen delivery pipe; 232. Nitrogen control valve; 233. Nitrogen source ; 24, exhaust port; 241, exhaust delivery pipe; 242, exhaust control valve; 243, waste liquid treatment area; 30, ammonia feeding area; 31, ammonia outlet; 311, ammonia delivery pipe; 312, metering pump; 40, ammonia mixer; 41, chilled water jacket; 50, cooling device; 51, chilled water inlet; 52, chilled water outlet; 51', chilled water inlet; 52', chilled water outlet; 60, weighbridge; 70, downstream reactor; 71, reactor; 72, feed mixer; 711, raw material source; 712, raw material delivery pipe; 713, material output pipe; 714, feed pipe; 80, lower partition; 90, upper partition; 91, connecting pipe. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that similar symbols and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition and explanation in the subsequent drawings.

[0036] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inside", "outside", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0039] Example 1

[0040] like Figure 1 The process flow chart of the ammonia water preparation and ammonia gas absorption device shown in the figure shows that the ammonia water preparation and ammonia gas absorption device disclosed in this embodiment includes an ammonia water container, which is a double-layer structure, and the inner layer is respectively provided with a raw material mixing storage area 10, an ammonia gas absorption area 20 and an ammonia water feeding area 30. Among them, the raw material mixing storage area 10 and the ammonia water feeding area 30 are arranged at the bottom area of ​​the ammonia water container, and the ammonia gas absorption area 20 is arranged at the top area of ​​the ammonia water container.

[0041] Depend on Figure 1It can be seen that the raw material mixing and storage area 10 of this embodiment is arranged on the left side of the bottom area of ​​the container, and is used to mix ammonia gas and desalted water to prepare an ammonia solution, thereby realizing the preparation function of the ammonia solution.

[0042] Specifically, an ammonia inlet 12 is provided on the side wall of the raw material mixing storage area 10, and the ammonia inlet 12 is connected to the ammonia source 123 through an ammonia delivery pipe 121. Further, the ammonia inlet 12 and the horizontal pipe 122 are connected through an L-shaped pipe, wherein the ammonia inlet 12 is arranged at a position higher than the top of the lower partition 80 on the side wall of the ammonia water container, which can prevent the ammonia water from flowing back into the ammonia delivery pipe 121, and the horizontal pipe 122 is arranged in parallel at the bottom of the raw material mixing storage area 10, and a plurality of small holes 124 are evenly distributed on the horizontal pipe 122, thereby, ammonia enters the horizontal pipe 122 through the ammonia delivery pipe 121, and enters the bottom of the raw material mixing storage area 10 through the small holes 124 dispersed on the horizontal pipe 122 to be dissolved in the desalted water. Since a large amount of heat is released when ammonia and desalted water are mixed, the evenly distributed small holes 124 allow the ammonia to be dispersedly dissolved in the desalted water, thereby avoiding excessive local temperature rise.

[0043] In this embodiment, the ammonia source 123 is a liquid ammonia cylinder, and the liquid ammonia cylinder is placed on a floor scale 60. The quality signal transmitted by the floor scale 60 is used to determine the amount of ammonia in the liquid ammonia cylinder, which is used to control the opening and closing of the ammonia pipeline.

[0044] A first desalted water inlet 11 is also provided in the raw material mixing storage area 10, and the first desalted water inlet 11 is connected to a desalted water source 112 through a first desalted water delivery pipe 111. The first desalted water inlet 11 in this embodiment is provided at the upper part of the horizontal pipe 122, so that the ammonia gas dispersed to the bottom of the raw material mixing storage area 10 can fully contact with the desalted water flowing downward, so that the ammonia gas is fully dissolved in the desalted water.

[0045] In this embodiment, an ammonia mixer 40 is further provided on the first desalted water delivery pipe 111 to change the input path of ammonia gas and assist in preparing ammonia solution with a higher concentration. Figure 1 It can be seen that the pipeline of the ammonia delivery pipe 121 is divided into two paths, one of which is connected to the ammonia inlet 12 and is provided with a first shut-off valve 125, and the other is connected to the ammonia mixer 40 and is provided with a second shut-off valve 126. A chilled water jacket 41 is provided outside the ammonia mixer 40, and the chilled water jacket 41 is provided with a chilled water inlet 51' and a chilled water outlet 52'. The temperature in the ammonia mixer 40 is quickly kept stable by the circulation of chilled water in the chilled water jacket 41.

[0046] Depend on Figure 1 It can be seen that the ammonia water feeding area 30 of this embodiment is arranged on the right side of the bottom area of ​​the container, and is used to receive the ammonia water solution from the raw material mixing storage area 10.

[0047] The raw material mixing storage area 10 and the ammonia water feeding area 30 are separated by a lower partition 80. The ammonia solution prepared in the raw material mixing storage area 10 can overflow the top of the lower partition 80 and enter the ammonia water feeding area 30 for storage to be used in downstream reactions.

[0048] An ammonia outlet 31 is provided at the bottom of the ammonia feed zone 30, and the ammonia outlet 31 is connected to the downstream reactor 70 through an ammonia delivery pipe 311, wherein the ammonia delivery pipe 311 is provided with a metering pump 312 that can control the flow rate of the ammonia solution, so as to adjust the flow rate of the ammonia solution flowing to the downstream reactor 70.

[0049] Furthermore, a bypass pipeline 127 connected to the ammonia delivery pipe 311 is provided at the bottom of the ammonia mixing storage area 10. When the upstream ammonia gas supply is suspended, the bypass valve 128 at the bottom of the ammonia mixing storage area 10 can be opened to deliver the ammonia in the ammonia mixing storage area 10 to the downstream reactor 70.

[0050] Depend on Figure 1 It can be seen that the ammonia absorption zone 20 of the present embodiment is arranged in the top area of ​​the container, and is separated from the raw material mixing storage zone 10 and the ammonia water feeding zone 30 by an upper partition 90. A connecting pipe 91 is provided on the upper partition 90, which leads upward into the ammonia water absorption zone 20. The ammonia in the raw material mixing storage zone 10 and the ammonia water feeding zone 30 can enter the ammonia absorption zone 20 through the connecting pipe 91 to be reabsorbed and used.

[0051] A nitrogen inlet 23 and an exhaust port 24 are respectively provided at the top of the ammonia absorption zone 20. The nitrogen inlet 23 is connected to a nitrogen source 233 through a nitrogen delivery pipe 231, and a nitrogen control valve 232 is provided on the nitrogen delivery pipe 231. The pressure in the container and the concentration of the prepared ammonia water are adjusted by controlling the nitrogen control valve 232 to adjust the nitrogen delivery amount; the exhaust port 24 is connected to a waste liquid treatment zone 243 through an exhaust delivery pipe 241, and an exhaust control valve 242 is provided on the exhaust delivery pipe 241. The pressure in the container is adjusted by controlling the exhaust control valve 242. A small amount of ammonia will be contained in the gas discharged through the exhaust delivery pipe 241, which can be absorbed in the waste liquid treatment zone 243 to prevent ammonia from entering the air and polluting the environment.

[0052] A second desalted water inlet 21 is also provided in the ammonia absorption zone 20, and the second desalted water inlet 21 is connected to a second desalted water source 212 through a second desalted water delivery pipe 211, and is used to replenish desalted water into the ammonia absorption zone 20 for absorbing volatilized ammonia. The second desalted water source 212 and the first desalted water source 112 may be two independent desalted water sources, or may be the same desalted water source.

[0053] An absorption liquid outlet 22 is also provided in the ammonia absorption zone 20, and the absorption liquid outlet 22 is connected to the first desalted water delivery pipe 111 through an absorption liquid output pipe 221. When the ammonia aqueous solution in the ammonia absorption zone 20 reaches a certain concentration, the absorption liquid can be returned to the first desalted water delivery pipe 111 through the absorption liquid output pipe 221, and then returned to the raw material mixing storage zone 10 for utilization.

[0054] In this embodiment, an ammonia absorption zone 20 is arranged on the upper part of the raw material mixing storage zone 10 and the ammonia water feeding zone 30 to absorb ammonia volatilized from the ammonia solution in the raw material mixing storage zone 10 and the ammonia water feeding zone 30, thereby realizing the recycling of volatilized ammonia in the system, improving the utilization rate of ammonia, and preventing the waste of ammonia; it also avoids ammonia from entering the air and polluting the environment; and it can also assist in the pressure regulation in the system to adjust the concentration of ammonia water.

[0055] Depend on Figure 1 It can be seen that the outer layer of the ammonia water container is a cooling device 50, which is used to control the temperature in the container within a certain range. The cooling device 50 is provided with a chilled water inlet 51 and a chilled water outlet 52, wherein the chilled water inlet 51 is arranged at the bottom of the cooling device 50, and the chilled water outlet 52 is arranged at the top of the cooling device 50. The cooling device 50 transfers the heat released when the ammonia gas is dissolved in water in the raw material mixing storage area 10 and the ammonia absorption area 20 through the circulation of chilled water, thereby ensuring the stability of the temperature in the raw material mixing storage area 10, the ammonia absorption area 20, and the ammonia water feeding area 30. In this embodiment, the cooling device 50 is a chilled water coil arranged outside the container.

[0056] Example 2

[0057] The device for preparing ammonia water and absorbing ammonia gas provided in this embodiment is the same as the device provided in Example 1, except that: Figure 2 As shown, the downstream reactor 70 in the device of this embodiment is an epoxidation reactor, specifically, an epoxidation reactor that uses propylene and hydrogen peroxide as raw materials to react to generate propylene oxide.

[0058] The epoxidation reactor includes a feed mixer 72 and a reactor 71. The feed mixer 72 is connected to the raw material source through a raw material delivery pipe 712, and is connected to the ammonia water feeding area 30 through an ammonia water delivery pipe 311, that is, the raw material is delivered to the feed mixer 72 and then mixed with ammonia water of a certain concentration. The flow rate of ammonia water entering the feed mixer 72 is controlled by a metering pump 312 provided on the ammonia water delivery pipe 311 to adjust the pH value of the system. The mixed raw materials in the feed mixer 72 are delivered to the reactor 71 through a feed pipe 714 for reaction, and the materials that have been completely reacted in the reactor 71 are delivered through a material output pipe 713. It can be seen that the ammonia solution stored in the ammonia water feeding area 30 can continuously and stably provide the reactor 71 with a stable concentration of ammonia solution to meet the epoxidation reaction in an appropriate pH system.

[0059] When the epoxidation reactor requires low concentration ammonia water, the device is operated as follows: open the first shut-off valve 125, close the second shut-off valve 126, transport ammonia gas and desalted water to the raw material mixing storage area 10, adjust and control the mass ratio of ammonia gas and desalted water entering the raw material mixing storage area 10 to be 1:8, open the nitrogen control valve 232, make the pressure in the raw material mixing storage area 10 to be 0.1 MPaG, open the cooling device 50, make the temperature in the ammonia water container to be 30°C, and the fully mixed ammonia solution overflows to the ammonia water feeding area 30 through the lower partition 80. At this time, the ammonia concentration obtained in the ammonia water feeding area 30 is 10%, and open the metering pump 312 to transport the ammonia water in the ammonia water feeding area 10 to the feed mixer 72, and then be mixed with the raw materials and sent to the reactor 71.

[0060] Example 3

[0061] The apparatus for preparing ammonia water and absorbing ammonia gas provided in this embodiment is the same as the apparatus provided in Example 2. The downstream reactor 70 in the apparatus of this embodiment is also an epoxidation reactor for reacting propylene and hydrogen peroxide as raw materials to generate propylene oxide.

[0062] When the epoxidation reactor requires low concentration ammonia water, the device is operated as follows: open the first shut-off valve 125, close the second shut-off valve 126, transport ammonia gas and desalted water to the raw material mixing storage area 10, adjust and control the mass ratio of ammonia gas and desalted water entering the raw material mixing storage area 10 to be 1:4, open the nitrogen control valve 232, make the pressure in the raw material mixing storage area 10 to be 0.1 MPaG, open the cooling device 50, make the temperature in the ammonia water container to be 30°C, and the fully mixed ammonia solution overflows to the ammonia water feeding area 30 through the lower partition 80. At this time, the ammonia concentration obtained in the ammonia water feeding area 30 is 20%, and open the metering pump 312, so that the ammonia water in the ammonia water feeding area 10 is transported to the feed mixer 72, and is mixed with the raw materials and then transported to the reactor 71.

[0063] Example 4

[0064] The apparatus for preparing ammonia water and absorbing ammonia gas provided in this embodiment is the same as the apparatus provided in Example 2. The downstream reactor 70 in the apparatus of this embodiment is also an epoxidation reactor for reacting propylene and hydrogen peroxide as raw materials to generate propylene oxide.

[0065] When a higher concentration of ammonia solution is required, the input path of ammonia needs to be changed. That is, the first shut-off valve 125 on the ammonia delivery pipe 121 is closed, and the input amount of nitrogen is adjusted by the nitrogen control valve 232 to increase the pressure in the raw material mixing storage area 10. The second shut-off valve 126 on the ammonia delivery pipe 121 leading to the ammonia mixer 40 is opened, and the ammonia is first sent to the ammonia mixer 40 to mix with the desalted water, and then sent to the raw material mixing storage area 10. After the ammonia entry method is changed, the ammonia mixer 40 allows a large amount of ammonia and desalted water to be quickly mixed and fully mixed. At the same time, the chilled water jacket 41 provided outside the ammonia mixer 40 ensures that the heat released by the ammonia dissolving in water can be quickly taken away, ensuring a larger amount of ammonia dissolved. At the same time, increasing the pressure of the ammonia container can also increase the concentration of ammonia.

[0066] When the epoxidation reactor requires high concentration of ammonia water, the device is operated as follows: close the first shut-off valve 125, open the second shut-off valve 126, transport ammonia gas and desalted water to the raw material mixing storage area 10, adjust and control the mass ratio of ammonia gas and desalted water entering the raw material mixing storage area 10 to be 1:3, open the nitrogen control valve 232, and increase the nitrogen input at the same time to increase the pressure in the raw material mixing storage area 10 to 0.7 MPaG, open the cooling device 50 and the chilled water jacket 41, so that the temperature in the ammonia water container and the ammonia mixer 40 is 30°C, and the fully mixed ammonia solution overflows to the ammonia water feeding area 30 through the lower partition 80. At this time, the ammonia concentration obtained in the ammonia water feeding area 30 is 25%, and start the metering pump 312 to transport the ammonia water in the ammonia water feeding area 10 to the feed mixer 72, and then mix with the raw materials and send it to the reactor 71.

[0067] Example 5

[0068] The apparatus for preparing ammonia water and absorbing ammonia gas provided in this embodiment is the same as the apparatus provided in Example 2. The downstream reactor 70 in the apparatus of this embodiment is also an epoxidation reactor for reacting propylene and hydrogen peroxide as raw materials to generate propylene oxide.

[0069] When the epoxidation reactor requires high concentration of ammonia water, the device is operated as follows: close the first shut-off valve 125, open the second shut-off valve 126, transport ammonia gas and desalted water to the raw material mixing storage area 10, adjust and control the mass ratio of ammonia gas and desalted water entering the raw material mixing storage area 10 to be 1:2, open the nitrogen control valve 232, and increase the nitrogen input at the same time to increase the pressure in the raw material mixing storage area 10 to 0.9 MPaG, open the cooling device 50 and the chilled water jacket 41, so that the temperature in the ammonia water container and the ammonia mixer 40 is 20°C, and the fully mixed ammonia solution overflows to the ammonia water feeding area 30 through the lower partition 80. At this time, the ammonia concentration obtained in the ammonia water feeding area 30 is 33%, and start the metering pump 312 to transport the ammonia water in the ammonia water feeding area 10 to the feed mixer 7, and then mix with the raw material and send it to the reactor 71.

[0070] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preparing ammonia water and absorbing ammonia gas, It is characterized in that The device includes an ammonia water container, which has a double-layer structure and includes a raw material mixing storage area, an ammonia water feeding area and an ammonia gas absorption area; the raw material mixing storage area and the ammonia water feeding area are respectively arranged on the left and right sides of the bottom area of ​​the container, and are separated by a lower partition; the ammonia gas absorption area is arranged in the top area of ​​the ammonia water container, and is separated from the raw material mixing storage area and the ammonia water feeding area by an upper partition, and a connecting pipe that leads upward into the ammonia water absorption area is provided on the upper partition.

2. The device for preparing ammonia water and absorbing ammonia gas according to claim 1, It is characterized in that An ammonia inlet and a first desalted water inlet are provided on the side wall of the ammonia water container in the raw material mixing and storage area, and the ammonia inlet is located higher than the top of the lower partition, and an ammonia source is connected to the ammonia inlet through an ammonia delivery pipe; the first desalted water source is connected to the first desalted water inlet through a first desalted water delivery pipe.

3. The device for preparing ammonia water and absorbing ammonia gas according to claim 2, It is characterized in that The ammonia inlet is connected to a horizontal pipe through an L-shaped pipe. The horizontal pipe is arranged at the bottom of the raw material mixing and storage area, and a plurality of small holes are evenly distributed on the horizontal pipe. The desalted water inlet is arranged at the upper part of the horizontal pipe.

4. The device for preparing ammonia water and absorbing ammonia gas according to claim 2, It is characterized in that An ammonia mixer is provided on the first desalination transport pipe, and a circulating chilled water jacket is provided outside the ammonia mixer; The pipeline of the ammonia delivery pipe is divided into two routes, one route is connected to the ammonia inlet and is provided with a first shut-off valve, and the other route is connected to the ammonia mixer and is provided with a second shut-off valve.

5. The device for preparing ammonia water and absorbing ammonia gas according to claim 1, It is characterized in that The ammonia absorption zone is provided with a second desalted water inlet, an absorption liquid outlet, a nitrogen inlet and an exhaust port. The second desalted water source is connected to the second desalted water inlet through a second desalted water delivery pipe, the absorption liquid outlet is connected to the first desalted water delivery pipe through an absorption liquid output pipe, the nitrogen source is connected to the nitrogen inlet through a nitrogen delivery pipe, and a nitrogen control valve is provided on the nitrogen delivery pipe, and the exhaust port is connected to the waste liquid treatment zone through an exhaust delivery pipe, and an exhaust control valve is provided on the exhaust delivery pipe.

6. The device for preparing ammonia water and absorbing ammonia gas according to claim 1, It is characterized in that An ammonia outlet is provided at the bottom of the ammonia feed zone, and the ammonia outlet is connected to a downstream reactor through an ammonia delivery pipe, and a metering pump is provided on the ammonia delivery pipe.

7. The device for preparing ammonia water and absorbing ammonia gas according to claim 6, It is characterized in that A bypass pipeline connected to the ammonia water delivery pipe is provided at the bottom of the raw material mixing storage area, and a bypass valve is provided on the bypass pipeline.

8. The device for preparing ammonia water and absorbing ammonia gas according to claim 6, It is characterized in that The downstream reactor is an epoxidation reactor, which includes a feed mixer and a reactor. The feed mixer is connected to a raw material source through a raw material delivery pipe, and is connected to the ammonia feed zone through the ammonia delivery pipe. The feed mixer is connected to the reactor through a feed pipe, and the material in the reactor is delivered through a material output pipe.

9. The device for preparing ammonia water and absorbing ammonia gas according to claim 1, It is characterized in that The system further comprises a cooling device, which is arranged outside the ammonia water container and is provided with a chilled water inlet and a chilled water outlet; Preferably, the chilled water inlet is arranged at the bottom of the cooling device, and the chilled water outlet is arranged at the top of the cooling device.

10. A method for preparing ammonia water and absorbing ammonia gas using the device according to any one of claims 1 to 9, It is characterized in that The method comprises the following steps: transporting ammonia gas and desalted water to a raw material mixing storage area, opening a nitrogen control valve to allow the raw material mixing storage area to reach a predetermined pressure; opening a cooling device to allow the raw material mixing storage area to maintain a predetermined temperature; the fully mixed ammonia solution overflows to an ammonia water feeding area through a lower baffle, and opening a metering pump to transport ammonia water in the ammonia water feeding area to a downstream reactor; and volatilized ammonia gas is absorbed in an ammonia gas absorption area; Preferably, the path for conveying ammonia gas to the raw material mixing storage area is adjusted by controlling the first shut-off valve and the second shut-off valve.

11. The method for preparing ammonia water and absorbing ammonia gas according to claim 10, It is characterized in that Controlling the feed mass ratio of ammonia gas and desalted water entering the raw material mixing storage area to be 1 / 8 to 1 / 2; Controlling the pressure of the raw material mixing storage area to be 0.1-0.9 MpaG; The temperature of the raw material mixing and storage area is controlled to be 20-35°C.

12. The method for preparing ammonia water and absorbing ammonia gas according to claim 10, It is characterized in that The concentration of the ammonia water delivered to the downstream reactor is 10-35%.

13. Use of the device for preparing ammonia water and absorbing ammonia gas according to claims 1 to 9, It is characterized in that Used to adjust the pH value of the downstream reaction system; preferably, The downstream reaction system is a reaction system in which propylene and hydrogen peroxide are used as raw materials to react in an epoxidation reactor to generate propylene oxide.

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