Nitrogen source supplementing system for dimethyl oxalate synthesis
By utilizing a nitrogen source replenishment system for dimethyl oxalate synthesis, and employing components such as multi-stage reaction chambers, control valves, and flow meters, the system effectively addresses nitrogen source loss and nitric acid flow issues caused by inert gas accumulation, achieving stable and efficient system operation and cost reduction.
Patent Information
- Application Number
- CN202423282930.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2034-12-30
AI Technical Summary
The cumulative effect of inert gases during the synthesis of dimethyl oxalate on the reaction rate causes the nitrogen source to be discharged from the system with the purge gas, resulting in a total nitrogen loss and increasing the cost of nitric acid treatment in subsequent processes.
A nitrogen source replenishment system for the synthesis of dimethyl oxalate was designed, including a nitric acid input pipeline, an alcohol-containing liquid input pipeline, and a nitric oxide-containing gas input pipeline. After being mixed by a mixer, the mixture enters a four-stage reaction chamber. Combined with control valves, flow meters, and level gauges, the system enables multi-stage repeatable reactions, reducing nitrogen source loss and nitric acid outflow.
It effectively reduces nitrogen source loss, lowers the cost of nitric acid transfer and treatment, ensures stable operation of the reaction system, reduces acid load in subsequent processes, and improves system efficiency.
Smart Images
Figure CN223846881U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to chemical reaction technical field, especially a kind of oxalic acid dimethyl ester synthesis nitrogen source replenishing system. BACKGROUND
[0002] Oxalic acid dimethyl ester synthesis principle: this process is with CO, CH3OH and O2 As raw material to synthesize oxalic acid dimethyl ester (DMO):
[0003] Reaction one: 2CO+2CH3ONO=DMO+2NO;
[0004] Reaction two: 2NO+1 / 2O2+2CH3OH=2CH3ONO+H2O;
[0005] Total reaction: 2CO+1 / 2O2+2CH3OH= (COOCH3) 2+H2O;
[0006] Under normal circumstances according to conservation law, N atom keeps constant, but oxalic acid dimethyl ester synthesis process due to the accumulation of inert gas can affect reaction rate, to ensure that reaction rate remains at a high level, need to be discharged by relaxation inert component, relatively can cause nitrogen source with relaxation gas to discharge system, to cause system total nitrogen loss, when it needs to be replenished by external nitrogen source, so as to keep system total nitrogen constant.
[0007] Due to the above situation, it is necessary to continuously replenish nitrogen source from the outside world to keep the total nitrogen constant, which will cause the loss of nitrogen source, and the system reaction will involve the circulation of nitric acid, which requires the subsequent section to strengthen the treatment of nitric acid, thereby also increasing the cost of investment in the entire system. Therefore, in view of the above problems, an oxalic acid dimethyl ester synthesis nitrogen source replenishing system is proposed. INVENTION CONTENTS
[0008] The utility model discloses to overcome in oxalic acid dimethyl ester synthesis process due to the accumulation of inert gas can affect reaction rate, need to be discharged by relaxation inert component, relatively can cause nitrogen source with relaxation gas to discharge system, to cause system total nitrogen loss, and system reaction will involve the circulation of nitric acid, which requires the subsequent section to strengthen the treatment of nitric acid, thereby also increasing the cost of investment in the entire system. The technical problem to be solved by the utility model is to provide an oxalic acid dimethyl ester synthesis nitrogen source replenishing system that can reduce the total nitrogen loss caused by relaxation inert component discharge and reduce the cost of investment in the subsequent section to strengthen the treatment of nitric acid due to the circulation of nitric acid in the system reaction.
[0009] In order to solve the above technical problems, the utility model provides a kind of oxalic acid dimethyl ester synthesis nitrogen source supplement system, including nitric acid input pipeline, alcohol-containing liquid input pipeline and contain nitric oxide gas input pipeline, the nitric acid input pipeline with the alcohol-containing liquid input pipeline all pass into mixer, the mixer is connected with mixed liquid output pipeline, the nitric oxide gas input pipeline with the mixed liquid output pipeline all pass into four-stage reaction chamber.
[0010] Preferably, the four-stage reaction chamber is composed of reaction one chamber, reaction two chamber, reaction three chamber and reaction four chamber, and the reaction one chamber, the reaction two chamber, the reaction three chamber and the reaction four chamber are connected in sequence.
[0011] Preferably, the nitric oxide gas input pipeline and the mixed liquid output pipeline both pass into the reaction one chamber.
[0012] Preferably, a first control valve is arranged between the nitric acid input pipeline and the mixer, a second control valve is arranged between the alcohol-containing liquid input pipeline and the mixer, and a third control valve is arranged between the nitric oxide gas input pipeline and the reaction one chamber.
[0013] Preferably, a nitric oxide gas input branch pipeline, a fourth control valve and a flowmeter are arranged between the nitric oxide gas input pipeline and the reaction one chamber, the reaction two chamber, the reaction three chamber and the reaction four chamber respectively, and the flowmeter is connected between the nitric oxide gas input branch pipeline and the fourth control valve.
[0014] Preferably, each nitric oxide gas input branch pipeline is communicated with the bottom of the corresponding reaction one chamber, reaction two chamber, reaction three chamber and reaction four chamber respectively.
[0015] Preferably, a liquid delivery pipeline, a fifth control valve and a liquid level meter are connected between the reaction one chamber and the reaction two chamber, between the reaction two chamber and the reaction three chamber, and between the reaction three chamber and the reaction four chamber, and the fifth control valve is connected with the liquid level meter between the corresponding reaction one chamber, reaction two chamber and reaction three chamber respectively.
[0016] Preferably, an acid-containing waste liquid discharge pipeline is communicated with the bottom of the reaction four chamber, the acid-containing waste liquid discharge pipeline is provided with a sixth control valve, and the sixth control valve is provided with the liquid level meter between the reaction four chamber.
[0017] Preferably, the reaction two chamber, the reaction three chamber and the reaction four chamber are communicated with a methyl nitrite gas phase branch pipeline, the reaction one chamber is communicated with a first methyl nitrite gas phase pipeline, each of the methyl nitrite gas phase branch pipelines is communicated with a second methyl nitrite gas phase pipeline, the first methyl nitrite gas phase pipeline is communicated with the second methyl nitrite gas phase pipeline, and the first methyl nitrite gas phase pipeline is provided with a seventh control valve.
[0018] Preferably, the number of the four-stage reaction chambers is two and the structures are the same.
[0019] Beneficial effects
[0020] The utility model discloses a nitric acid input pipeline is set up to input the nitric acid from the outside world, and the alcohol-containing liquid input pipeline and the nitric oxide gas input pipeline are set up to circulate the alcohol-containing liquid and the nitric oxide gas from the reaction system, and then the alcohol-containing liquid and the nitric oxide gas enter the reaction system again, and the mixer is set up to mix the nitric acid from the outside world and the methanol from the reaction system in advance, so that the nitric acid and the methanol can react with the nitric oxide from the reaction system more fully, and through the four-stage reaction chamber, the nitric oxide, the nitric acid and the methanol can react fully and effectively, and the loss of the nitrogen source is reduced, and the outflow of the nitric acid is also reduced, and the processing cost of the discharged nitric acid in the subsequent section is reduced.
[0021] The utility model discloses a plurality of control valves, flowmeters and liquid level meters are set up, and the reaction can be controlled effectively in each circulation stage according to the real-time reaction condition, whether it is the nitric oxide gas, the nitric acid or the methanol or even the methyl nitrite generated finally, so that the relatively ideal reaction effect is achieved.
[0022] The utility model discloses that the nitric oxide gas input branch pipeline is communicated with the reaction one chamber, the reaction two chamber, the reaction three chamber and the reaction four chamber bottom, forms the effect of gas phase and liquid phase bubble feeding, makes the circulating nitric oxide gas and methanol and nitric acid fully react, and further cooperates with a plurality of control valves, flowmeters and liquid level meters, adjusts the bubble gas volume of each chamber, controls the total nitrogen content of the synthesis system, and guarantees that the reaction system runs stably under full load. ACCURACY
[0023] In order to make the technical scheme of the embodiments of the utility model or the prior art clearer, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without paying creative labor.
[0024] Figure 1 It is the connection schematic drawing of the oxalic acid dimethyl ester synthesis nitrogen source supplement system in the utility model.
[0025] Explanation of reference numerals in the diagram: 100, Nitric acid input pipeline; 1001, First control valve; 101, Alcohol-containing liquid input pipeline; 1011, Second control valve; 102, Nitric oxide-containing gas input pipeline; 1021, Third control valve; 103, Mixer; 104, Nitric oxide gas input branch pipeline; 105, Fourth control valve; 106, Flow meter; 107, Mixed liquid output pipeline; 108, Reaction chamber one; 109, Reaction chamber two; 110, Reaction chamber three; 111, Reaction chamber four; 112, Level gauge; 113, Liquid delivery pipeline; 114, Fifth control valve; 115, Methyl nitrite gas phase branch pipeline; 116, Second methyl nitrite gas phase pipeline; 117, Acid-containing waste liquid discharge pipeline; 118, First methyl nitrite gas phase pipeline; 1181, Seventh control valve; 119, Sixth control valve. Detailed Implementation
[0026] To further understand the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not intended to limit the scope of the invention.
[0027] Example 1
[0028] A nitrogen source supplementation system for dimethyl oxalate synthesis, such as Figure 1 As shown, it includes a nitric acid input pipe 100, an alcohol-containing liquid input pipe 101, and a nitric oxide gas input pipe 102. The nitric acid input pipe 100 and the alcohol-containing liquid input pipe 101 are both connected to a mixer 103. The mixer 103 is connected to a mixed liquid output pipe 107. The nitric oxide gas input pipe 102 and the mixed liquid output pipe 107 are both connected to a four-stage reaction chamber.
[0029] The four-stage reaction chamber consists of reaction chamber 108, reaction chamber 2 109, reaction chamber 3 110 and reaction chamber 4 111, which are connected in sequence.
[0030] The nitric oxide gas input pipe 102 and the mixed liquid output pipe 107 both lead into the reaction chamber 108.
[0031] A first control valve 1001 is provided between the nitric acid input pipeline 100 and the mixer 103, a second control valve 1011 is provided between the alcohol-containing liquid input pipeline 101 and the mixer 103, and a third control valve 1021 is provided between the nitric oxide-containing gas input pipeline 102 and the reaction chamber 108.
[0032] The nitrogen monoxide gas input pipeline 102 is provided with a nitrogen monoxide gas input branch pipeline 104, a fourth control valve 105 and a flow meter 106 between the reaction one chamber 108, the reaction two chamber 109, the reaction three chamber 110 and the reaction four chamber 111 respectively, and the flow meter 106 is connected between the nitrogen monoxide gas input branch pipeline 104 and the fourth control valve 105.
[0033] Each of the nitrogen monoxide gas input branch pipelines 104 is communicated with the bottom of the corresponding reaction one chamber 108, reaction two chamber 109, reaction three chamber 110 and reaction four chamber 111 respectively.
[0034] The reaction one chamber 108, the reaction two chamber 109, the reaction three chamber 110 and the reaction four chamber 111 are connected with a liquid delivery pipeline 113, a fifth control valve 114 and a liquid level meter 112 between the reaction one chamber 108 and the reaction two chamber 109, the reaction two chamber 109 and the reaction three chamber 110, the reaction three chamber 110 and the reaction four chamber 111, and the liquid level meter 112 is connected between the fifth control valve 114 and the corresponding reaction one chamber 108, reaction two chamber 109 and reaction three chamber 110 respectively.
[0035] The reaction four chamber 111 is communicated with an acid-containing waste liquid discharge pipeline 117 at the bottom, the acid-containing waste liquid discharge pipeline 117 is provided with a sixth control valve 119, and the liquid level meter 112 is arranged between the sixth control valve 119 and the reaction four chamber 111.
[0036] The reaction two chamber 109, the reaction three chamber 110 and the reaction four chamber 111 are communicated with a methyl nitrite gas phase branch pipeline 115, the reaction one chamber 108 is communicated with a first methyl nitrite gas phase pipeline 118, each of the methyl nitrite gas phase branch pipelines 115 is communicated with a second methyl nitrite gas phase pipeline 116, the first methyl nitrite gas phase pipeline 118 is communicated with the second methyl nitrite gas phase pipeline 116, and the first methyl nitrite gas phase pipeline 118 is provided with a seventh control valve 1181.
[0037] The number of the four-stage reaction chambers is two and the structures are the same.
[0038] Working principle: the nitrogen source supplementing system has the reaction principle that:
[0039] HNO3+2NO+3CH3OH=3CH3ONO+2H2O, wherein NO is extracted from the synthesis gas after the completion of the reaction system, and is introduced into the first reaction chamber 108 of the fourth reaction chamber through the NO-containing gas input pipeline 102, CH3OH is supplemented by the alcohol-containing liquid after the completion of the reaction of the reaction system, and is introduced into the mixer 103 through the alcohol-containing liquid input pipeline 101, and HNO3 is supplemented from the outside, and is introduced into the mixer 103 through the HNO3 input pipeline 100. The HNO3 and CH3OH are mixed in the mixer 103 in advance to facilitate rapid and effective reaction with the NO gas in the first reaction chamber 108. At the same time, the first control valve 1001 and the flow meter 106 provided on the HNO3 input pipeline 100 can effectively control the volume of HNO3 entering the mixer 103, and the second control valve 1011 provided on the alcohol-containing liquid input pipeline 101 can effectively control the volume of CH3OH entering the mixer 103, so that the three can better react in the first reaction chamber 108;
[0040] The unreacted components of the alcohol-containing liquid and HNO3 mixture entering the first reaction chamber 108 will pass through the liquid delivery pipeline 113 into the second reaction chamber 109, and then successively into the third reaction chamber 110 and the fourth reaction chamber 111. At the same time, the NO-containing gas will also enter the first reaction chamber 108, the second reaction chamber 109, the third reaction chamber 110 and the fourth reaction chamber 111 through the NO-containing gas input branch pipelines 104. During this period, the fourth control valve 105 and the flow meter 106 are used to effectively control the volume of NO-containing gas entering the first reaction chamber 108 to the fourth reaction chamber 111, and the liquid level meter 112 and the fifth control valve 114 are used to effectively control the volume of the mixture in the first reaction chamber 108 to the fourth reaction chamber 111, so that the first reaction chamber 108 to the fourth reaction chamber 111 can complete the reaction efficiently;
[0041] The gaseous phase containing CH3ONO produced in the second reaction chamber 109 to the fourth reaction chamber 111 will enter the CH3ONO gaseous phase branch pipeline 115, and then enter the second CH3ONO gaseous phase pipeline 116, and finally enter the first CH3ONO gaseous phase pipeline 118 together with the gaseous phase containing CH3ONO produced in the first reaction chamber 108 to be re-supplied into the synthesis system, so as to realize the supplement of the nitrogen source;
[0042] The acid-containing waste liquid from the reaction four chamber 111 will finally be discharged to the outside through the acid-containing waste liquid discharge pipeline 117. After sufficient reaction in the reaction one chamber 108 to the reaction four chamber 111, the nitric acid content at the outlet of the reaction four chamber 111 is greatly reduced, thereby reducing the acid load of the subsequent section and further reducing the processing cost.
[0043] Further, the seventh control valve 1181 and the flow meter 106 provided in the first methylene nitrite gas phase pipeline 118 can effectively control the methylene nitrite content entering the next reaction system.
[0044] Further, the sixth control valve 119 provided in the acid-containing waste liquid discharge pipeline 117 and the liquid level meter 112 of the reaction four chamber 111 can better control the nitric acid content at the outlet of the reaction four chamber 111.
[0045] Further, the number of four-stage reaction chambers is two and the structures are the same, which can speed up the working efficiency of the entire system, form effective echo with the front and rear systems, and greatly improve the reaction and operation process of the system.
[0046] Further, the nitrogen monoxide gas input branch pipeline 104 is communicated with the bottom of the reaction one chamber 108, the reaction two chamber 109, the reaction three chamber 110 and the reaction four chamber 111, forming the effect of gas phase and liquid phase bubbling feeding, so that the circulating nitrogen monoxide gas and methanol and nitric acid are fully reacted, the total nitrogen content of the synthesis system can be controlled by adjusting the bubbling gas amount of each chamber, and the reaction system can be ensured to run stably at full load.
[0047] Further, the system adopts four-stage reaction chambers, thereby reducing the acid load of the subsequent section. The results show that the nitric acid content at the outlet of the reaction four chamber 111 is always maintained below 0.5% under the full load running state, which is good. If a three-stage structure is adopted, the expected effect cannot be achieved, and if a five-stage structure is adopted, the cost will be wasted too much and the benefit cannot compensate the cost.
[0048] Further, for the entire system, the nitrogen monoxide gas flow rate of the reaction one chamber 108 is controlled at 2500-6900 cubic meters / hour, the nitrogen monoxide gas flow rate of the reaction two chamber 109 is controlled at 2000-3400 cubic meters / hour, the nitrogen monoxide gas flow rate of the reaction three chamber 110 is controlled at 1500-3600 cubic meters / hour, and the nitrogen monoxide gas flow rate of the reaction four chamber 111 is controlled at 800-1500 cubic meters / hour.
[0049] Further, the nitric acid flow rate from the outside is controlled at 16-250 kilograms / hour.
[0050] Further, the temperature of the reaction one chamber 108 is controlled at 60-68 degrees, the temperature of the reaction two chamber 109 is controlled at 65-78 degrees, and the temperature of the reaction three chamber 110 and the reaction four chamber 111 is controlled at 65-78 degrees.
[0051] The liquid levels of the reaction one chamber 108, the reaction two chamber 109, the reaction three chamber 110 and the reaction four chamber 111 are controlled at about 55%.
[0052] The above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the above examples, it should be understood by those skilled in the art that the specific embodiments of the present application can still be modified or replaced equivalently without departing from the spirit and scope of the present application. Any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered within the protection scope of the claims of the present application.
Claims
1. An oxymethyl synthesis nitrogen source supplement system, characterized in that, The application relates to a four-stage reaction chamber for producing nitric acid, which comprises a nitric acid input pipeline (100), an alcohol-containing liquid input pipeline (101) and a nitric oxide gas input pipeline (102), the nitric acid input pipeline (100) and the alcohol-containing liquid input pipeline (101) are both connected with a mixer (103), the mixer (103) is connected with a mixed liquid output pipeline (107), the nitric oxide gas input pipeline (102) and the mixed liquid output pipeline (107) are both connected with a four-stage reaction chamber.
2. The oxymethyl synthesis nitrogen source supplement system of claim 1, wherein, The four-stage reaction chamber is composed of a first reaction chamber (108), a second reaction chamber (109), a third reaction chamber (110) and a fourth reaction chamber (111), the first reaction chamber (108), the second reaction chamber (109), the third reaction chamber (110) and the fourth reaction chamber (111) are sequentially connected.
3. The oxymethyl synthesis nitrogen source supplement system of claim 2, wherein, The nitric oxide gas input pipeline (102) and the mixed liquid output pipeline (107) are both connected with the first reaction chamber (108).
4. The oxymethyl synthesis nitrogen source supplement system of claim 2, wherein, A first control valve (1001) is arranged between the nitric acid input pipeline (100) and the mixer (103), a second control valve (1011) is arranged between the alcohol-containing liquid input pipeline (101) and the mixer (103), and a third control valve (1021) is arranged between the nitric oxide gas input pipeline (102) and the first reaction chamber (108).
5. The oxymethyl synthesis nitrogen supplement system of claim 2, wherein, Nitric oxide gas input branch pipelines (104), fourth control valves (105) and flow meters (106) are arranged between the nitric oxide gas input pipeline (102) and the first reaction chamber (108), the second reaction chamber (109), the third reaction chamber (110) and the fourth reaction chamber (111) respectively, and the flow meters (106) are connected between the nitric oxide gas input branch pipelines (104) and the fourth control valves (105).
6. The oxymethyl synthesis nitrogen source supplement system of claim 5, wherein, Each of the nitric oxide gas input branch pipelines (104) is connected with the bottom of the corresponding first reaction chamber (108), second reaction chamber (109), third reaction chamber (110) and fourth reaction chamber (111).
7. The oxymethyl synthesis nitrogen supplement system of claim 2, wherein, Liquid output pipelines (113), fifth control valves (114) and liquid level meters (112) are arranged between the first reaction chamber (108) and the second reaction chamber (109), between the second reaction chamber (109) and the third reaction chamber (110), and between the third reaction chamber (110) and the fourth reaction chamber (111), and the liquid level meters (112) are connected between the fifth control valves (114) and the corresponding first reaction chamber (108), second reaction chamber (109) and third reaction chamber (110).
8. The oxymethyl synthesis nitrogen source supplement system of claim 7, wherein, An acid-containing waste liquid discharge pipeline (117) is connected with the bottom of the fourth reaction chamber (111), the acid-containing waste liquid discharge pipeline (117) is provided with a sixth control valve (119), and the sixth control valve (119) is provided with the liquid level meter (112).
9. The oxymethyl synthesis nitrogen supplement system of claim 2, wherein, The reaction two chamber (109), the reaction three chamber (110) and the reaction four chamber (111) are communicated with methyl nitrite gas phase branch pipelines (115), the reaction one chamber (108) is communicated with a first methyl nitrite gas phase pipeline (118), each of the methyl nitrite gas phase branch pipelines (115) is communicated with a second methyl nitrite gas phase pipeline (116), the first methyl nitrite gas phase pipeline (118) is communicated with the second methyl nitrite gas phase pipeline (116), and the first methyl nitrite gas phase pipeline (118) is provided with a seventh control valve (1181).
10. The oxymethyl synthesis nitrogen source supplement system of claim 1, wherein, The number of the four-stage reaction chambers is two and the structures are the same.