Rectifying tower for removing acetaldehyde from butadiene extraction solvent
By introducing an acetaldehyde removal distillation column system into the butadiene extraction unit, and utilizing sieve trays and reflux control technology to remove acetaldehyde impurities, the polymerization problem caused by acetaldehyde enrichment was solved, and stable operation and efficient production of the unit were achieved.
Patent Information
- Application Number
- CN202520039766.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-08
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2035-01-08
AI Technical Summary
Acetaldehyde impurities in the butadiene extraction unit can lead to polymerization reactions, causing system blockage and unstable operation, which affects the safety and output of the unit.
Design an acetaldehyde removal distillation column system including components such as a solvent removal column, condenser, reflux tank, reflux pump, column bottom pump, and steam reboiler. The system removes acetaldehyde impurities through sieve trays and reflux control, preventing its accumulation in the solvent.
It effectively removes acetaldehyde impurities, improves solvent purity, extends the operating cycle of the unit, reduces the frequency of shutdowns for maintenance, lowers maintenance costs, and improves the quality and yield of butadiene products.
Smart Images
Figure CN223668680U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of deacetaldehyde rectification, concretely is a kind of butadiene extraction solvent deacetaldehyde rectification tower. BACKGROUND
[0002] In the running process of butadiene extraction device, there is a rather thorny problem, that is, the acetaldehyde impurity content in mixed carbon four raw materials is high. When mixed carbon four raw materials are continuously transported into the extraction rectification unit of device, these impurities are mixed therein. The solvent recovery system of the device itself has obvious limitations, it cannot effectively separate acetaldehyde impurities, and then cannot realize the purification operation of circulating solvent acetonitrile. In this way, acetaldehyde impurities start the enrichment and accumulation process in the circulating acetonitrile solvent system.
[0003] It is worth noting that when acetaldehyde reaches a certain enrichment degree in the circulating acetonitrile solvent, in the first extraction rectification tower kettle and stripping tower kettle parts, due to the relatively high temperature of the process design of these areas, acetaldehyde becomes the "oxygen" catalyst to cause butadiene polymerization. Under its catalysis, butadiene begins to polymerize, and the generated polymer gradually accumulates, causing polymer plugging in many places of the system pipeline, equipment and other places. This polymerization problem is like a "time bomb", seriously interfering with the stable and orderly operation of the extraction rectification system of device, making it difficult to stabilize the operating parameters of the whole system, and the fluctuation is frequent. If it is not properly solved for a long time, it will pose a huge hidden danger to the safe long-period operation of the device, which may not only lead to frequent unplanned shutdown for maintenance, increase maintenance cost and labor input, but also affect the yield and quality of butadiene product, weaken the competitiveness of the device in the market.
[0004] The acetaldehyde impurities in the butadiene extraction device circulating acetonitrile solvent continuously enrich and accumulate, the acetaldehyde impurity content in the solvent of stripping tower kettle reaches 0.15%, and the acetaldehyde impurity content in the solvent of acetylene flash tower kettle is higher, reaching 2-3%. Research finds that the enriched acetaldehyde impurities will undergo condensation polymerization under alkaline conditions to generate β-hydroxy aldehyde; at the same time, high-concentration butadiene in the device reacts with aldehyde to generate copolymer of acetaldehyde and butadiene, which is yellow rubber. The pump filter of the first extraction rectification kettle and stripping kettle of extraction rectification unit of device continuously discharges such yellow butadiene rubber-like self-polymer, and it is found that the corresponding tower, heat exchanger, pump, valve, pipeline and flowmeter are seriously hung with "glue (self-polymer)". This polymerization problem seriously affects the safe and stable operation of the device; at the same time, it needs to be regularly stopped for cleaning polymer, which shortens the operation period of the device. Therefore, our company starts to research and develop butadiene extraction solvent deacetaldehyde rectification tower. UTILITY MODEL CONTENTS
[0005] The utility model discloses a butadiene extraction solvent deacetaldehyde rectifying tower to solve the technical problem that butadiene polymerization occurs in the local of the extraction rectification system of butadiene device mentioned in the background art.
[0006] The above technical purpose of the present application is realized by the following technical scheme:
[0007] A butadiene extraction solvent deacetaldehyde rectifying tower, comprising a solvent deacetaldehyde tower, a solvent deacetaldehyde tower condenser, a solvent deacetaldehyde tower reflux tank, a solvent deacetaldehyde tower reflux pump, a solvent deacetaldehyde tower kettle pump, a solvent deacetaldehyde tower steam reboiler, a solvent deacetaldehyde tower feed flow meter, a solvent deacetaldehyde tower feed regulating valve, a solvent deacetaldehyde tower reflux tank liquid level meter, a solvent deacetaldehyde tower reflux regulating valve, a solvent deacetaldehyde tower top production regulating valve, a solvent deacetaldehyde tower kettle liquid level meter, a solvent deacetaldehyde tower kettle production regulating valve and a solvent deacetaldehyde tower sieve plate tray, characterized in that: the solvent deacetaldehyde tower feed flow meter and the solvent deacetaldehyde tower feed regulating valve are connected with the solvent deacetaldehyde tower through pipelines, the bottom of the solvent deacetaldehyde tower is communicated with the solvent deacetaldehyde tower steam reboiler, the solvent deacetaldehyde tower, the solvent deacetaldehyde tower kettle pump and the solvent deacetaldehyde tower kettle production regulating valve, the solvent deacetaldehyde tower upper solvent deacetaldehyde tower kettle liquid level meter, the top of the solvent deacetaldehyde tower is respectively connected with the solvent deacetaldehyde tower condenser, the solvent deacetaldehyde tower reflux tank, the solvent deacetaldehyde tower reflux pump and the solvent deacetaldehyde tower top production regulating valve through pipelines, the solvent deacetaldehyde tower reflux tank upper solvent deacetaldehyde tower reflux tank liquid level meter, a pipeline is led out between the solvent deacetaldehyde tower reflux pump and the solvent deacetaldehyde tower top production regulating valve and connected with the top of the solvent deacetaldehyde tower, and the solvent deacetaldehyde tower reflux regulating valve is arranged on the led-out pipeline.
[0008] Preferably, the solvent deacetaldehyde tower is provided with solvent deacetaldehyde tower sieve plate trays.
[0009] The utility model discloses a technical effect and advantage:
[0010] (1) improve the adaptability of the device to raw materials, increase the removal capacity of the device to part of low-boiling-point impurities in the raw materials.
[0011] (2) purify the circulating acetonitrile solvent, avoid the process problems such as solvent quality decline and extraction selectivity decline caused by the enrichment and accumulation of methanol, ethanol, acetaldehyde and other impurities.
[0012] (3) the running period of the circulating acetonitrile solvent is prolonged, and the cost of replacing fresh acetonitrile solvent in a large range due to the deterioration of the solvent quality is saved.
[0013] (4) The solvent deacetalization purification outlet is arranged at the acetylene flash tower tank outlet pipeline, because the acetaldehyde concentration is the highest at the acetylene flash tower tank outlet. The solvent is purified at the acetylene flash tower tank outlet, so that the acetaldehyde impurities in the solvent can be removed more effectively. BRIEF DESCRIPTION OF DRAWINGS
[0014] Fig. 1 The system diagram of the present application;
[0015] Fig. 2 The sieve plate tray structure diagram of the solvent deacetalization tower of the present application.
[0016] In the figure: 1. solvent deacetalization tower; 2. solvent deacetalization tower condenser; 3. solvent deacetalization tower reflux tank; 4. solvent deacetalization tower reflux pump; 5. solvent deacetalization tower tank pump; 6. solvent deacetalization tower steam reboiler; 7. solvent deacetalization tower feed flow meter; 8. solvent deacetalization tower feed regulating valve; 9. solvent deacetalization tower reflux tank liquid level meter; 10. solvent deacetalization tower reflux regulating valve; 11. solvent deacetalization tower overhead outlet regulating valve; 12. solvent deacetalization tower tank liquid level meter; 13. solvent deacetalization tower tank outlet regulating valve; 14. sieve plate tray of solvent deacetalization tower. DETAILED DESCRIPTION
[0017] The application will be further described in detail below with reference to the accompanying drawings.
[0018] The specific embodiments are only used to explain the application, and are not used to limit the application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and the modifications are protected by the patent law as long as the modifications are within the scope of the claims of the application.
[0019] In one embodiment, refer to Figs. 1-2The application relates to a butadiene extractive solvent deacetaldehyde rectification tower, which comprises a solvent deacetaldehyde tower 1, a solvent deacetaldehyde tower condenser 2, a solvent deacetaldehyde tower reflux tank 3, a solvent deacetaldehyde tower reflux pump 4, a solvent deacetaldehyde tower kettle pump 5, a solvent deacetaldehyde tower steam reboiler 6, a solvent deacetaldehyde tower feed flow meter 7, a solvent deacetaldehyde tower feed adjusting valve 8, a solvent deacetaldehyde tower reflux tank liquid level meter 9, a solvent deacetaldehyde tower reflux adjusting valve 10, a solvent deacetaldehyde tower top production adjusting valve 11, a solvent deacetaldehyde tower kettle liquid level meter 12, a solvent deacetaldehyde tower kettle production adjusting valve 13 and a solvent deacetaldehyde tower sieve tray 14, wherein the solvent deacetaldehyde tower feed flow meter 7 and the solvent deacetaldehyde tower feed adjusting valve 8 are connected with the solvent deacetaldehyde tower 1 through pipelines; the solvent deacetaldehyde tower 1 is communicated with the solvent deacetaldehyde tower steam reboiler 6 arranged at the bottom of the solvent deacetaldehyde tower 1; the solvent deacetaldehyde tower 1, the solvent deacetaldehyde tower kettle pump 5 and the solvent deacetaldehyde tower kettle production adjusting valve 13, the solvent deacetaldehyde tower kettle liquid level meter 12 arranged on the solvent deacetaldehyde tower 1, the solvent deacetaldehyde tower 1 top, the solvent deacetaldehyde tower condenser 2, the solvent deacetaldehyde tower reflux tank 3, the solvent deacetaldehyde tower reflux pump 4 and the solvent deacetaldehyde tower top production adjusting valve 11 are connected through pipelines; the solvent deacetaldehyde tower reflux tank liquid level meter 9 is arranged on the solvent deacetaldehyde tower reflux tank 3; a pipeline is led out between the solvent deacetaldehyde tower reflux pump 4 and the solvent deacetaldehyde tower top production adjusting valve 11 and connected with the solvent deacetaldehyde tower 1 top; the solvent deacetaldehyde tower reflux adjusting valve 10 is arranged on the led-out pipeline; and the solvent deacetaldehyde tower sieve tray 14 is arranged in the solvent deacetaldehyde tower 1.
[0020] The device uses the following method: the amount of solvent returned to the stripping tower from the acetylene flash column is 18 t / h, and 1.8 t / h of solvent is extracted to pass through the solvent deacetaldehyde tower feed flow meter 7, the solvent deacetaldehyde tower feed regulating valve 8 to control the amount of entering the solvent deacetaldehyde tower 1 for rectification and purification. The solvent deacetaldehyde tower steam reboiler 6 is put into use, and low-pressure steam 1.0 t / h is input. After the vaporized solvent is completely condensed by the solvent deacetaldehyde tower condenser 2, it enters the solvent deacetaldehyde tower reflux tank 3, and the solvent deacetaldehyde tower reflux pump 4 is used to pump the solvent in the solvent deacetaldehyde tower reflux tank 3 into the solvent deacetaldehyde tower 1 as reflux liquid. The liquid level of the solvent deacetaldehyde tower reflux tank 3 is uniformly controlled by the solvent deacetaldehyde tower reflux tank liquid level meter 9 and the solvent deacetaldehyde tower reflux regulating valve 10, and the liquid level is maintained at 45-55%. In order to prevent the enrichment of acetaldehyde at the top of the solvent deacetaldehyde tower 1, the solvent at the top of the solvent deacetaldehyde tower is intermittently extracted by the solvent deacetaldehyde tower top extraction regulating valve 11 (extraction amount 1 t / time, extraction frequency 2 times / week), and the extracted waste liquid is treated as hazardous waste in a barrel. (The solvent deacetaldehyde tower 1 tower bottom is the purified solvent for removing acetaldehyde impurities, which is extracted by the solvent deacetaldehyde tower bottom pump 5 and returned to the stripping tower. The liquid level of the solvent deacetaldehyde tower 1 tower bottom is uniformly controlled by the solvent deacetaldehyde tower bottom liquid level meter 12 and the solvent deacetaldehyde tower bottom extraction regulating valve 13, and the liquid level is maintained at 45-55%. In order to prevent the polymerization reaction of high-concentration acetaldehyde in the solvent deacetaldehyde tower 1, the sieve plate tray 14 is used for the solvent deacetaldehyde tower 1 tray.
Claims
1. A butadiene extractive solvent dehydroacetalization rectification column comprising a solvent dehydroacetalization column (1), a solvent dehydroacetalization column condenser (2), a solvent dehydroacetalization column reflux drum (3), a solvent dehydroacetalization column reflux pump (4), a solvent dehydroacetalization column column pump (5), a solvent dehydroacetalization column steam reboiler (6), a solvent dehydroacetalization column feed flow meter (7), a solvent dehydroacetalization column feed control valve (8), a solvent dehydroacetalization column reflux drum level gauge (9), a solvent dehydroacetalization column reflux control valve (10), a solvent dehydroacetalization column overhead take-off control valve (11), a solvent dehydroacetalization column column level gauge (12), a solvent dehydroacetalization column column take-off control valve (13), and a solvent dehydroacetalization column sieve tray (14), characterized by: The solvent deacetalization tower feed flow meter (7) and the solvent deacetalization tower feed regulating valve (8) are connected with the solvent deacetalization tower (1) through pipelines, the solvent deacetalization tower (1) is communicated with the solvent deacetalization tower steam reboiler (6) arranged at the bottom, the solvent deacetalization tower (1), the solvent deacetalization tower bottom pump (5) and the solvent deacetalization tower bottom product regulating valve (13) are communicated, the solvent deacetalization tower (1) is provided with the solvent deacetalization tower bottom liquid level meter (12), the top of the solvent deacetalization tower (1) is communicated with the solvent deacetalization tower condenser (2), the solvent deacetalization tower reflux tank (3), the solvent deacetalization tower reflux pump (4) and the solvent deacetalization tower top product regulating valve (11) through pipelines respectively, the solvent deacetalization tower reflux tank (3) is provided with the solvent deacetalization tower reflux tank liquid level meter (9), a pipeline is led out between the solvent deacetalization tower reflux pump (4) and the solvent deacetalization tower top product regulating valve (11) and connected with the top of the solvent deacetalization tower (1), and the solvent deacetalization tower reflux regulating valve (10) is arranged on the led-out pipeline.
2. The butadiene extractive solvent deacetaldehyde rectification column of claim 1, wherein: The solvent deacetalization tower (1) is provided with the solvent deacetalization tower sieve tray (14) in sections.