Amino alcohol separation apparatus and method for co-producing oxamide and dimethyl oxalate

Abstract

The application discloses an ammonia-alcohol separation device, which comprises, from top to bottom, a methanol absorption section, a methanol condensation and extraction section, an ammonia absorption section and an ammonia absorption raw material preparation section. The methanol absorption section absorbs methanol in gas through desalted water, the methanol condensation and extraction section sends the extracted methanol to a dimethyl oxalate synthesis device, and the ammonia absorption section absorbs ammonia in gas through a methanol solution of dimethyl oxalate. The ammonia-alcohol separation device further comprises a dimethyl oxalate rectification device and an oxamide synthesis device. The chemical reaction in the oxamide production process is used to replace the rectification and washing processes in the prior art, so that the complete conversion of ammonia is realized, methanol is internally circulated in the dimethyl oxalate synthesis and oxamide co-production device, and the low-level thermal energy of dimethyl oxalate is effectively utilized. The application further discloses a dimethyl oxalate and oxamide co-production method using the ammonia-alcohol separation device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tail gas treatment, in particular to an ammonia-methanol separation device. BACKGROUND

[0002] Oxamide is an important organic compound, which is used as a high-efficiency slow-release nitrogen fertilizer in the agricultural field to supply nitrogen elements for crops. In the medical field, it is an important raw material for synthesizing polypeptides and proteins, and it is also an important raw material for synthesizing polyamide high molecular materials.

[0003] The preparation of oxamide by reacting dimethyl oxalate with ammonia is the most promising production method in the industry. In the process of preparing oxamide by ammonolysis of dimethyl oxalate, in order to ensure the purity of oxamide, ammonia needs to be excessive, so that the tail gas generally contains nitrogen, methanol and ammonia in the subsequent separation and drying process.

[0004] In a plant for producing dimethyl oxalate and co-producing oxamide by using synthesis gas, carbon monoxide is generally used as a raw material to produce dimethyl oxalate by gas-phase coupling method, and 2 moles of methanol are consumed for producing 1 mole of dimethyl oxalate; correspondingly, 1 mole of dimethyl oxalate is consumed for producing 1 mole of oxamide and 2 moles of methanol are produced as by-products. It can be seen that if dimethyl oxalate is produced from synthesis gas and then ammonolysis to produce oxamide, methanol can be regarded as an intermediate circulating product.

[0005] The existing ammonia-methanol gas separation scheme in the production process of oxamide generally condenses methanol and ammonia into liquid, and then separates methanol and ammonia by distillation operation. The separated ammonia is compressed and returned to the front end of the oxamide preparation process by ammonolysis of dimethyl oxalate. The separated methanol generally contains a small amount of ammonia, and this part of methanol needs to be further deaminated before returning to the dimethyl oxalate synthesis device or sold as methanol product. This technical scheme has the disadvantages of large equipment investment, high steam and circulating water consumption, etc.

[0006] Therefore, how to overcome the above technical defects is a problem to be solved by those skilled in the art. SUMMARY

[0007] The purpose of the present application is to provide an ammonia-methanol separation device, which realizes the complete conversion of ammonia by chemical method and the recycling of methanol between the dimethyl oxalate synthesis device and the oxamide synthesis device. Another purpose of the present application is to provide a method for co-producing dimethyl oxalate and oxamide by using the above ammonia-methanol separation device.

[0008] To solve the above technical problems, the present application provides an ammonia alcohol separation device, comprising methanol absorption section, methanol condensation section, ammonia absorption section and ammonia absorption raw material preparation section arranged from top to bottom, the methanol absorption section absorbs methanol in gas through desalted water, the methanol condensation section sends the methanol to oxalic acid dimethyl ester synthesis device, the ammonia absorption section absorbs ammonia in gas through methanol solution of oxalic acid dimethyl ester, further comprising oxalic acid dimethyl ester rectification device and oxamide synthesis device, the oxalic acid dimethyl ester rectification device is used to output oxalic acid dimethyl ester with preset temperature, and the oxamide synthesis device is used to produce oxamide, and methanol and ammonia produced in the production process are sent to corresponding positions.

[0009] Preferably, the methanol absorption section comprises a first cylinder, the upper end of the first cylinder is provided with an upper head, the lower end of the first cylinder is provided with a first isolation tower plate, and the first cylinder is sequentially provided with a desalted water nozzle, a methanol absorption first filler, a circulating water solution nozzle, a methanol absorption second filler and a first riser pipe from top to bottom.

[0010] Preferably, the upper head is provided with a gas exhaust port, a nitrogen inlet and a pressure gauge port, the side wall of the first cylinder is sequentially provided with a desalted water inlet, a circulating water solution inlet, a first overflow port and a circulating water solution outlet from top to bottom, and the side wall of the first cylinder is further provided with a first liquid level meter upper interface, a first liquid level meter lower interface and a first thermometer interface.

[0011] Preferably, the methanol condensation section comprises a second cylinder and a heat exchange pipe bundle, a baffle plate and a second riser pipe installed in the second cylinder, the lower part of the second cylinder is provided with a second isolation tower plate, the heat exchange pipe bundle is vertically arranged, and a plurality of baffle plates are horizontally arranged alternately.

[0012] Preferably, the side wall of the second cylinder is sequentially provided with a cooling liquid inlet, a cooling liquid outlet, a second overflow port and a methanol outlet from top to bottom, and the side wall of the second cylinder is further sequentially provided with a second liquid level meter upper interface, a second thermometer interface and a second liquid level meter lower interface from top to bottom.

[0013] Preferably, the ammonia absorption section comprises a third cylinder, the third cylinder is provided with a first anti-collision baffle, a sieve plate tray and a second anti-collision baffle, the first anti-collision baffle is arranged at the upper end of the third cylinder, the second anti-collision baffle is arranged at the middle end of the third cylinder, and a plurality of sieve plate trays are horizontally arranged alternately.

[0014] Preferably, the side wall of the third cylinder is sequentially provided with an oxalic acid dimethyl ester methanol liquid inlet, a circulating absorption liquid inlet and a tail gas inlet from top to bottom.

[0015] Preferably, the ammonia absorption raw material preparation section comprises a fourth cylinder, a liquid flow guide plate is arranged in the fourth cylinder, and a baffle is arranged at the lower end of the fourth cylinder.

[0016] Preferably, the side wall of the fourth cylinder on the left side of the baffle is sequentially provided with an oxymethyl dimethyl ester inlet and a methanol inlet from top to bottom, the fourth cylinder is provided with an oxymethyl dimethyl ester methanol solution outlet on the left side of the baffle, the fourth cylinder is provided with a circulating absorption liquid outlet on the right side of the baffle, the side wall of the fourth cylinder on the left side of the baffle is sequentially provided with a third liquid level meter upper interface, a third thermometer interface and a third liquid level meter lower interface from top to bottom, and the side wall of the fourth cylinder on the right side of the baffle is sequentially provided with a fourth liquid level meter upper interface, a fourth thermometer interface and a fourth liquid level meter lower interface from top to bottom.

[0017] The application provides a method for co-producing oxymethyl dimethyl ester and oxamide, and the method comprises the following steps:

[0018] S1: oxymethyl dimethyl ester at 135 DEG C directly introduced from the oxymethyl dimethyl ester heat exchanger of the oxymethyl dimethyl ester rectification device is introduced into the oxymethyl dimethyl ester inlet of the ammonia absorption raw material preparation section and mixed with the methanol collected from the methanol outlet;

[0019] S2: the oxymethyl dimethyl ester methanol solution is pumped out from the oxymethyl dimethyl ester methanol solution outlet to the oxymethyl dimethyl ester methanol liquid inlet and flows downward, reacts with the ammonia in the tail gas generated by the oxamide synthesis device to produce oxamide, and flows into the right side area of the baffle of the ammonia absorption raw material preparation section, and then is pumped out from the circulating absorption liquid outlet, part of which goes to the oxamide reactor of the oxamide synthesis device, and part of which goes to the circulating absorption liquid inlet to absorb the ammonia in the tail gas of the oxamide synthesis device;

[0020] S3: the methanol gas without ammonia and nitrogen enter the methanol condensation collection section from the second gas lifting pipe, most of the methanol is condensed in the methanol condensation collection section and is collected above the second isolation tower plate, and the methanol is pumped to the methanol inlet of the ammonia absorption raw material preparation section to be mixed with the oxymethyl dimethyl ester in part, and is pumped to the crude oxymethyl dimethyl ester production section to produce crude oxymethyl dimethyl ester in part, the crude oxymethyl dimethyl ester is refined in the oxymethyl dimethyl ester rectification device, and then is sent to the oxamide synthesis device and the ammonia alcohol separation device, so that the methanol circulates among the ammonia alcohol separation device, the oxymethyl dimethyl ester device and the oxamide synthesis device;

[0021] S4: the circulating absorption liquid pumped out from the oxamide reactor of the oxamide synthesis device reacts with excess ammonia to generate oxamide, and the material discharged from the oxamide synthesis reactor contains oxamide, methanol and ammonia;

[0022] S5: The material discharged from the oxamide reactor of the oxamide synthesis device is subjected to flash evaporation, filtration and drying to obtain oxamide powder, and the gas containing methanol, ammonia and nitrogen generated in the process is sent to the ammonia alcohol separation device, so that the ammonia is completely converted into oxamide product between the ammonia alcohol separation device and the oxamide synthesis device, and the liquid containing methanol and ammonia generated by the oxamide synthesis device is heated to a certain temperature and then enters the lower part of the ammonia absorption section of the ammonia alcohol separation device to realize ammonia alcohol separation.

[0023] The application provides an ammonia alcohol separation device, which comprises, from top to bottom, a methanol absorption section, a methanol condensation and extraction section, an ammonia absorption section and an ammonia absorption raw material preparation section.

[0024] The oxamide produced by the oxamide synthesis device is used as raw material, and all tail gas generated in the oxamide synthesis device is collected and transported to the ammonia alcohol separation device, in which the oxamide and ammonia in the tail gas react to generate oxamide which is pumped into the oxamide synthesis reactor to realize complete conversion of ammonia; the methanol tail gas without ammonia is condensed in the ammonia alcohol separation device provided by the application and pumped into the oxamide synthesis device as raw material for oxamide synthesis, so as to realize internal circulation of methanol in the oxamide synthesis device; finally, the tail gas containing a small amount of methanol is washed with a circulating water solution and desalted water, and the washed water is sent to a sewage treatment device to supplement the carbon source.

[0025] The application also provides a method for producing oxamide by using the ammonia alcohol separation device, which has the same technical effects as the ammonia alcohol separation device and will not be described in detail here. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The structure diagram of a specific embodiment of the ammonia alcohol separation device provided by the application. DETAILED DESCRIPTION

[0027] The core of the present application is to provide an ammonia alcohol separation device, which realizes complete conversion of ammonia and recycling of methanol between dimethyl oxalate synthesis device and oxamide synthesis device by using chemical method. Another core of the present application is to provide a dimethyl oxalate co-production oxamide method using the above ammonia alcohol separation device.

[0028] In order to make the person skilled in the art better understand the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0029] Please refer to Figure 1 , Figure 1 The structure diagram of one specific embodiment of the ammonia alcohol separation device provided by the present application.

[0030] The present application provides an ammonia alcohol separation device, which comprises, from top to bottom, a methanol absorption section, a methanol condensation and extraction section, an ammonia absorption section and an ammonia absorption raw material preparation section. The methanol absorption section absorbs methanol in gas through desalinated water, and the ammonia absorption section absorbs ammonia in gas through dimethyl oxalate methanol solution. The ammonia alcohol separation device further comprises a dimethyl oxalate rectification device and an oxamide synthesis device. The dimethyl oxalate rectification device is used to output dimethyl oxalate at a preset temperature, and the oxamide synthesis device is used to produce oxamide and send methanol, ammonia and the like produced in the production process to the ammonia alcohol separation device.

[0031] The dimethyl oxalate introduced from the dimethyl oxalate production device is used as raw material to produce oxamide. All tail gas produced in the oxamide synthesis device is collected and transported to the ammonia alcohol separation device. In the ammonia alcohol separation device, dimethyl oxalate and ammonia in the tail gas react to generate oxamide and are pumped into an oxamide synthesis reactor, thereby realizing complete conversion of ammonia. Methanol tail gas without ammonia is condensed in the ammonia alcohol separation device provided by the present application and is pumped to the dimethyl oxalate synthesis device as raw material for synthesis of dimethyl oxalate, thereby realizing internal circulation of methanol in the dimethyl oxalate synthesis co-production oxamide device. Finally, the tail gas containing a small amount of methanol is washed with a circulating water solution and desalinated water, and the washed water is sent to a sewage treatment device to supplement carbon source. The chemical reaction in the oxamide production process is used to replace the rectification and washing processes in the prior art, thereby realizing complete conversion of ammonia, internal circulation of methanol in the dimethyl oxalate synthesis co-production oxamide device and effective utilization of low-level thermal energy of dimethyl oxalate. The present application has the advantages of high equipment integration, small investment, low energy consumption, no waste liquid and waste solid, etc.

[0032] In the ammonia alcohol separation device provided in the embodiment of the present application, the methanol absorption section adopts a double-layer packing tower structure, the upper layer of absorption liquid adopts desalted water, and the lower layer adopts a circulating water solution, so that the absorption effect can be ensured while the amount of desalted water is saved. The ammonia alcohol separation device comprises a first cylinder 12, an upper head 11 is arranged at the upper end of the first cylinder 12, a first isolation tower plate 18 is arranged at the lower end of the first cylinder 12, and a desalted water nozzle 13, a methanol absorption first packing 14, a circulating water solution nozzle 15, a methanol absorption second packing 16, a first gas-lift pipe 17 and a first overflow port N15 are arranged in the first cylinder 12 from top to bottom.

[0033] The first gas-lift pipe 17 is provided with a pipe cap above the first gas-lift pipe 17 to prevent the liquid above from entering below the first isolation tower plate 18.

[0034] Specifically, the upper head 11 is provided with a gas outlet N11, a nitrogen inlet N12 and a pressure gauge port P11, the side wall of the first cylinder 12 is sequentially provided with a desalted water inlet N13, a circulating water solution inlet N14, a first overflow port N15 and a circulating water solution outlet N16 from top to bottom, and the side wall of the first cylinder 12 is further provided with a first liquid level meter upper interface L11, a first liquid level meter lower interface L12 and a first thermometer interface T11.

[0035] In the ammonia alcohol separation device provided in the embodiment of the present application, the methanol condensation section comprises a second cylinder 23 and a heat exchange pipe bundle 21, a baffle plate 22 and a second gas-lift pipe 24 arranged in the second cylinder 23, a second isolation tower plate 25 is arranged below the second cylinder 23, the heat exchange pipe bundle 21 is vertically arranged, and a plurality of baffle plates 22 are horizontally and alternately arranged.

[0036] Specifically, the side wall of the second cylinder 23 is sequentially provided with a cooling liquid inlet N21 and a cooling liquid outlet N22, a second overflow port N23 and a methanol outlet N24 from top to bottom, and the side wall of the second cylinder 23 is further sequentially provided with a second liquid level meter upper interface L21, a second thermometer interface T21 and a second liquid level meter lower interface L22 from top to bottom.

[0037] In the ammonia alcohol separation device provided in the embodiment of the present application, the ammonia absorption section adopts a multi-layer plate tower, which can effectively prevent blockage, the upper layer of absorption liquid of the ammonia absorption section adopts a relatively pure oxalic acid dimethyl ester methanol solution, and the lower layer adopts a circulating absorption liquid, so that the ammonia absorption effect can be improved. The ammonia absorption section comprises a third cylinder 32, the third cylinder 32 is provided with a first anti-collision baffle 31, a sieve plate tray 33 and a second anti-collision baffle 34, the first anti-collision baffle 31 is arranged at the upper end of the third cylinder 32, the second anti-collision baffle 34 is arranged at the middle end of the third cylinder 32, and a plurality of sieve plate trays 33 are horizontally and alternately arranged.

[0038] Specifically, the third cylinder 32 side wall from top to bottom in turn is provided with oxalic acid dimethyl ester methanol liquid import N31, circulating absorption liquid import N32 and tail gas import N33.

[0039] On the basis of the ammonia alcohol separation device provided in the above embodiments, the ammonia absorption raw material preparation section includes a fourth cylinder 42, the fourth cylinder 42 is provided with a liquid flow guide plate 41 and a partition plate 43, the liquid flow guide plate 41 is inclinedly arranged at the upper end of the fourth cylinder 42, and the partition plate 43 is vertically arranged at the lower end of the fourth cylinder 42.

[0040] Specifically, the fourth cylinder 42 side wall located at the left side of the partition plate 43 is provided with an oxalic acid dimethyl ester import N41 and a methanol import N42 from top to bottom in turn, the fourth cylinder 42 located at the left side of the partition plate 43 is provided with an oxalic acid dimethyl ester methanol solution outlet N43, the fourth cylinder 42 located at the right side of the partition plate 43 is provided with a circulating absorption liquid outlet N44, the fourth cylinder 42 side wall located at the left side of the partition plate 43 is provided with a third liquid level meter upper interface L41, a third thermometer interface T41 and a third liquid level meter lower interface L42 from top to bottom in turn, and the fourth cylinder 42 side wall located at the right side of the partition plate 43 is provided with a fourth liquid level meter upper interface L43, a fourth thermometer interface T42 and a fourth liquid level meter lower interface L44 from top to bottom in turn.

[0041] The above-mentioned interfaces are connected to the corresponding components to realize the smooth flow of fluid and the detection of the running state of the equipment, and the positions and layout modes of the interfaces can be adjusted according to the situation. Further, the above-mentioned sections and components to be connected are connected through flanges, and of course, threaded connections or welding can also be used, which are all within the protection scope of the present application.

[0042] All the tail gas containing nitrogen, methanol and ammonia collected from the oxamide synthesis device enters the ammonia absorption section from the N33 port and moves upward under the action of pressure, and then contacts the circulating absorption liquid and the methanol solution of oxalic acid dimethyl ester sprayed in the ammonia absorption section on the sieve plate, ammonia reacts with oxalic acid dimethyl ester to generate oxamide, and the methanol and nitrogen gas of ammonia continue to rise and are discharged from the second riser into the methanol condensation and recovery section, the tail gas exchanges heat with the cooling water from the shell side of the methanol condensation and recovery section, most of the methanol is condensed and recovered, part of which is sent to the oxalic acid dimethyl ester synthesis device to participate in the synthesis of oxalic acid dimethyl ester, and the other part is used as a solvent to mix with oxalic acid dimethyl ester in the left side region of the partition plate of the ammonia absorption raw material preparation section.

[0043] The tail gas of the methanol condensation and recovery section enters the methanol absorption section through the first riser, and the methanol absorption section is a two-section packed tower, the lower section uses a circulating water solution containing methanol to wash and absorb the methanol tail gas, and the upper section uses desalted water to further remove the methanol in the tail gas until it meets the emission standard.

[0044] The 135℃ dimethyl oxalate from the dimethyl oxalate heat exchanger of the dimethyl oxalate synthesis device enters the left side area of the ammonia absorption raw material preparation section, is mixed with part of the methanol condensed and collected from the methanol collection section, and is pumped to the dimethyl oxalate methanol solution inlet. Due to the excess of dimethyl oxalate, the dimethyl oxalate methanol solution after absorbing ammonia still contains a large amount of dimethyl oxalate and methanol, which moves downward under the action of gravity and is mixed with the circulating absorption liquid to enter the right side area of the ammonia absorption raw material preparation section.

[0045] The main components of the right side area of the ammonia absorption raw material preparation section are dimethyl oxalate, methanol and oxamide, part of which is used as the circulating absorption liquid to wash the tail gas in the middle part of the ammonia absorption section, and the other part is pumped into the oxamide reactor of the oxamide synthesis device for preparing oxamide.

[0046] Part of the circulating water absorption liquid from the bottom of the methanol absorption section is used for washing and absorbing methanol, and part of it is sent to the sewage treatment device as a carbon source supplement for sewage treatment.

[0047] By adjusting the packing height of the methanol absorption tower and the desalted water injection amount, the methanol content in the tail gas can be controlled to meet the specified emission standard.

[0048] The embodiment of the present application provides a method for co-producing dimethyl oxalate and oxamide, which applies the ammonia alcohol separation device according to any one of the above, and comprises the following steps:

[0049] S1: directly introducing 135℃ dimethyl oxalate from the dimethyl oxalate heat exchanger of the dimethyl oxalate rectification device to the dimethyl oxalate inlet N41 in the ammonia absorption raw material preparation section, and mixing with the methanol collected from the methanol collection outlet N24;

[0050] S2: the dimethyl oxalate methanol solution is pumped out from the dimethyl oxalate methanol solution outlet N43 to the dimethyl oxalate methanol liquid inlet N31 and flows downward, reacts with the ammonia in the tail gas produced by the oxamide synthesis device to produce oxamide, and flows into the right side area of the partition 43 of the ammonia absorption raw material preparation section, and then is pumped out from the circulating absorption liquid outlet N44, part of which goes to the oxamide synthesis reactor of the oxamide synthesis device, and part of which goes to the circulating absorption liquid inlet N32 to absorb the ammonia in the tail gas of the oxamide synthesis device;

[0051] S3: Ammonia-free methanol gas and nitrogen gas from the second riser 24 enter the methanol condensing and collecting section, most of the methanol is condensed in the methanol condensing and collecting section and collected above the second isolation tray 25, the methanol is pumped from the methanol collecting outlet N24 to the methanol inlet N42 of the ammonia absorption raw material preparation section to mix with dimethyl oxalate; another part is pumped to the dimethyl oxalate synthesis section to produce crude dimethyl oxalate, and the crude dimethyl oxalate is refined in the dimethyl oxalate rectification device and then sent to the oxamide synthesis device and the ammonia alcohol separation device, so as to realize the circulation of methanol among the ammonia alcohol separation device, the dimethyl oxalate device and the oxamide synthesis device;

[0052] S4: The circulating absorption liquid and excess ammonia pumped out of the oxamide synthesis reactor of the oxamide synthesis device react to generate oxamide, and the material discharged from the oxamide synthesis reactor contains oxamide, methanol and ammonia;

[0053] S5: The material discharged from the oxamide synthesis reactor of the oxamide synthesis device is subjected to flashing, filtering and drying to obtain oxamide powder, and the gas containing methanol, ammonia and nitrogen generated in the process is sent to the ammonia alcohol separation device, so as to realize the complete conversion of ammonia into oxamide product between the ammonia alcohol separation device and the oxamide synthesis device, and the liquid containing methanol and ammonia generated by the oxamide synthesis device can be heated to a certain temperature and then introduced into the lower part of the ammonia absorption section of the ammonia alcohol separation device to realize ammonia alcohol separation in the ammonia alcohol separation device.

[0054] The ammonia alcohol separation device provided by the present application is described in detail above. In this paper, specific examples are used to describe the principles and implementation modes of the present application, and the above examples are only used to help understand the method of the present application and its core idea. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. An ammonia alcohol separation device, characterized by, The device comprises a methanol absorption section, a methanol condensing and collecting section, an ammonia absorption section and an ammonia absorption raw material preparation section arranged from top to bottom, the methanol absorption section absorbs methanol in gas by desalted water, the methanol condensing and collecting section collects methanol, part of which is sent to a dimethyl oxalate synthesis device and part of which is sent to the ammonia absorption raw material preparation section, the ammonia absorption section absorbs ammonia in gas by dimethyl oxalate methanol solution, and the device further comprises a dimethyl oxalate rectification device and an oxamide synthesis device, the dimethyl oxalate rectification device is used for outputting dimethyl oxalate at a preset temperature and sending the dimethyl oxalate to the ammonia absorption raw material preparation section, and the oxamide synthesis device is used for producing oxamide and sending methanol and ammonia generated in the production process to the tail gas inlet. The methanol absorption section comprises a first cylinder (12), an upper head (11) is arranged at the upper end of the first cylinder (12), a gas discharge port (N11) is arranged on the upper head (11), a first isolation tower plate (18) is arranged at the lower end of the first cylinder (12), and a first riser (17) is arranged in the first cylinder (12), tail gas of the methanol condensing and collecting section enters the methanol absorption section through the first riser. The methanol condensing and collecting section comprises a second cylinder (23) and a second riser (24) installed in the second cylinder (23), a second isolation tower plate (25) is arranged below the second cylinder (23), methanol and nitrogen gas from which ammonia is removed continue to rise and are discharged into the methanol condensing and collecting section from the second riser, and a methanol collecting outlet (N24) is arranged on the side wall of the second cylinder (23). The ammonia absorption section comprises a third cylinder (32), and a dimethyl oxalate methanol solution inlet (N31), a circulating absorption liquid inlet (N32) and a tail gas inlet (N33) are arranged on the side wall of the third cylinder (32) from top to bottom. The ammonia absorption raw material preparation section comprises a fourth cylinder (42), a partition plate (43) is arranged in the fourth cylinder (42), the partition plate (43) is vertically arranged at the lower end in the fourth cylinder (42), a dimethyl oxalate inlet (N41) and a methanol inlet (N42) are arranged on the side wall of the fourth cylinder (42) from top to bottom at the left side of the partition plate (43), a dimethyl oxalate methanol solution outlet (N43) is arranged at the left side of the partition plate (43) of the fourth cylinder (42), a circulating absorption liquid outlet (N44) is arranged at the right side of the partition plate (43) of the fourth cylinder (42), and part of the solution of the circulating absorption liquid outlet is sent to the oxamide synthesis device and part of the solution is sent to the circulating absorption liquid inlet.

2. The ammonia alcohol separation device of claim 1, wherein, The first cylinder (12) comprises a desalted water spray head (13), a methanol absorption first filler (14), a circulating water solution spray head (15), a methanol absorption second filler (16) and the first riser (17) arranged from top to bottom.

3. The ammonia alcohol separation device of claim 2, wherein, The upper head (11) is further provided with a nitrogen inlet (N12) and a pressure gauge port (P11), the first cylinder (12) is sequentially provided with a desalted water inlet (N13), a circulating water solution inlet (N14), a first overflow port (N15) and a circulating water solution outlet (N16) from top to bottom, and the first cylinder (12) is further provided with a first liquid level gauge upper interface (L11), a first liquid level gauge lower interface (L12) and a first thermometer interface (T11).

4. The ammonia alcohol separation device of claim 1, wherein, The methanol condensation extraction section further comprises heat exchange tube bundles (21) and baffles (22) installed inside the second cylinder (23), the heat exchange tube bundles (21) are vertically arranged, and a plurality of the baffles (22) are horizontally arranged alternately.

5. The ammonia alcohol separation device of claim 4, wherein, The second cylinder (23) is sequentially provided with a cooling liquid inlet (N21), a cooling liquid outlet (N22), a second overflow port (N23) and a methanol extraction outlet (N24) from top to bottom, and the second cylinder (23) is further sequentially provided with a second liquid level gauge upper interface (L21), a second thermometer interface (T21) and a second liquid level gauge lower interface (L22) from top to bottom.

6. The ammonia alcohol separation device of claim 1, wherein, The third cylinder (32) is provided with a first anti-collision baffle (31), sieve plate trays (33) and a second anti-collision baffle (34), the first anti-collision baffle (31) is arranged at the upper end of the third cylinder (32), the second anti-collision baffle (34) is arranged at the middle end of the third cylinder (32), and a plurality of the sieve plate trays (33) are arranged alternately.

7. The ammonia alcohol separation device according to any one of claims 1 to 6, characterized in that, The fourth cylinder (42) is provided with a liquid flow guide plate (41), and the liquid flow guide plate (41) is arranged obliquely at the upper end inside the fourth cylinder (42).

8. The ammonia alcohol separation device of claim 7, wherein, The side wall of the fourth cylinder (42) located at the left side of the partition plate (43) is sequentially provided with a third liquid level gauge upper interface (L41), a third thermometer interface (T41) and a third liquid level gauge lower interface (L42) from top to bottom, and the side wall of the fourth cylinder (42) located at the right side of the partition plate (43) is sequentially provided with a fourth liquid level gauge upper interface (L43), a fourth thermometer interface (T42) and a fourth liquid level gauge lower interface (L44) from top to bottom.

9. A process for the co-production of dimethyl oxalate and oxamide, characterized in that, The application of the ammonia alcohol separation device as claimed in any one of claims 1 to 8 comprises the following steps: S1: introducing 135℃ dimethyl oxalate directly from the dimethyl oxalate heat exchanger of the dimethyl oxalate rectification device to the dimethyl oxalate inlet (N41) in the ammonia absorption raw material preparation section, and mixing with the methanol extracted from the methanol extraction outlet (N24); S2: the dimethyl oxalate methanol solution is pumped out from the dimethyl oxalate methanol solution outlet (N43) to the dimethyl oxalate methanol liquid inlet (N31) to flow downward, reacts with the ammonia in the tail gas generated by the oxamide synthesis device to produce oxamide, and flows into the right side area of the partition plate (43) of the ammonia absorption raw material preparation section, and then is pumped out from the circulating absorption liquid outlet (N44), part of which goes to the oxamide synthesis reactor of the oxamide synthesis device, and part of which goes to the circulating absorption liquid inlet (N32) to absorb the ammonia in the tail gas of the oxamide synthesis device; S3: Ammonia-free methanol gas and nitrogen gas from the second riser (24) enter the methanol condensing and collecting section, most of the methanol is condensed in the methanol condensing and collecting section and collected above the second isolation tray (25), part of the methanol is pumped from the methanol outlet (N24) to the methanol inlet (N42) of the ammonia absorption raw material preparation section to mix with dimethyl oxalate; another part is pumped to the dimethyl oxalate synthesis section to produce crude dimethyl oxalate, the crude dimethyl oxalate is refined in the dimethyl oxalate rectification device and then sent to the oxamide synthesis device and the ammonia alcohol separation device, realizing the circulation of methanol among the ammonia alcohol separation device, the dimethyl oxalate synthesis device and the oxamide synthesis device; S4: The circulating absorption liquid and excess ammonia pumped to the oxamide synthesis reactor of the oxamide synthesis device react to generate oxamide, the material discharged from the oxamide synthesis reactor contains oxamide, methanol and ammonia; S5: The material discharged from the oxamide synthesis reactor of the oxamide synthesis device is subjected to flashing, filtering and drying to obtain oxamide powder, the gas containing methanol, ammonia and nitrogen generated in the process is sent to the ammonia alcohol separation device, realizing the complete conversion of ammonia into oxamide product between the ammonia alcohol separation device and the oxamide synthesis device, the liquid containing methanol and ammonia generated from the oxamide synthesis device is heated to a certain temperature and then enters the lower part of the ammonia absorption section of the ammonia alcohol separation device, realizing ammonia alcohol separation.

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