Molecular sieve coupling nitrogen-sealed fatty alcohol-polyoxyethylene ether low-aldehyde-value purification system and method

Abstract

The invention discloses a molecular sieve coupled nitrogen-sealed fatty alcohol-polyoxyethylene ether low-aldehyde-value purification system. The system comprises a molecular sieve unit, a nitrogen sealing unit, a control unit, a microwave regeneration module, a vortex generator and a Pd-Ag alloy catalytic trap, the molecular sieve unit adopts a ZSM-5 type modified molecular sieve of which the surface is coated with a Co-Mn catalyst; the nitrogen sealing unit comprises an inert gas supply device and a pressure adjusting device based on pressure difference feedback; the control unit comprises a temperature sensor and an automatic regulating valve; the microwave regeneration module periodically irradiates the molecular sieve unit at the frequency of 2.45 GHz; an outlet of the nitrogen sealing unit is provided with a vortex generator to form an annular nitrogen curtain to cover the surface of the molecular sieve; and a Pd-Ag alloy catalytic trap is integrated at the tail end of the system. The adsorption capacity is improved and the dead angle problem is solved.

Description

Technical Field

[0001] This invention relates to the field of fatty alcohol polyoxyethylene ether production processes, specifically to a low aldehyde value purification system and method for fatty alcohol polyoxyethylene ether using molecular sieve coupling and nitrogen sealing. Background Technology

[0002] Existing low aldehyde value purification systems for fatty alcohol polyoxyethylene ethers typically include a molecular sieve unit for adsorbing impurities, a nitrogen-sealing unit providing an inert environment, and a control unit for basic regulation. The methods employed involve adsorption and nitrogen protection steps. Existing systems achieve insufficient aldehyde value reduction, often exceeding 0.1%, due to reasons including: 1. Low molecular sieve adsorption efficiency; 2. Nitrogen-sealing dead zones leading to localized oxygen infiltration and a rebound in aldehyde value above 0.05%; 3. The control unit only monitors basic parameters and cannot dynamically optimize the process, thus affecting product purity. Current technologies achieve aldehyde values ​​of approximately 0.1-0.2% after purification, but are energy-intensive, complex, and susceptible to environmental impurities (such as oxygen and moisture), causing aldehyde value fluctuations. Therefore, improvements are urgently needed. Summary of the Invention

[0003] To address the above problems, this invention provides a purification system and method for low aldehyde value of fatty alcohol polyoxyethylene ethers coupled with molecular sieve and nitrogen sealing, which improves adsorption capacity and solves the dead zone problem.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a molecular sieve-coupled nitrogen-sealed low-aldehyde-value purification system for fatty alcohol polyoxyethylene ethers, comprising a molecular sieve unit, a nitrogen-sealing unit, a control unit, a microwave regeneration module, a vortex generator, and a Pd-Ag alloy catalytic trap; the molecular sieve unit employs a ZSM-5 type modified molecular sieve with a surface coated with a Co-Mn catalyst; the nitrogen-sealing unit includes an inert gas supply device and a pressure regulating device based on differential pressure feedback; the control unit includes a temperature sensor and an automatic regulating valve; the microwave regeneration module periodically irradiates the molecular sieve unit at a frequency of 2.45 GHz; the outlet of the nitrogen-sealing unit is equipped with a vortex generator to form an annular nitrogen curtain covering the surface of the molecular sieve; and a Pd-Ag alloy catalytic trap is integrated at the end of the system.

[0005] Preferably, the nitrogen flow velocity gradient of the vortex generator is: 2.5±0.2 L / min in the central region and 1.2±0.1 L / min in the edge region.

[0006] Preferably, the activation cycle of the microwave regeneration module is 10 minutes of irradiation every 2 hours of operation, with a power density of 50 W / cm². 2 .

[0007] Preferably, the Pd-Ag alloy catalyst trap has a mesh density of 200 mesh and a Pd / Ag mass ratio of 1:3.

[0008] A method for purifying low-aldehyde-value fatty alcohol polyoxyethylene ethers using molecular sieve-coupled nitrogen-sealed purification, based on a molecular sieve-coupled nitrogen-sealed purification system for low-aldehyde-value fatty alcohol polyoxyethylene ethers, includes the following steps:

[0009] (a) The raw material is preheated to 60±5℃ and then passed into the molecular sieve unit;

[0010] (b) The nitrogen sealing unit maintains the system pressure at 1.5 ± 0.1 atm, and the eddy current generator is activated to form an air curtain isolation layer;

[0011] (c) Trigger microwave regeneration for 10 minutes every 2 hours of operation;

[0012] (d) The product was purified a second time using a Pd-Ag catalytic trap.

[0013] Preferably, in step (b), the nitrogen purity is ≥99.99% and the oxygen content is ≤10ppm.

[0014] Preferably, during microwave regeneration, hydrogen gas, accounting for 5% of the total inert gas, is injected simultaneously to reduce aldehydes to alcohols adsorbed on the surface of the molecular sieve in situ.

[0015] Preferably, the operating temperature of the Pd-Ag catalytic trap is 80±5℃.

[0016] Preferably, the control unit integrates an AI algorithm to dynamically adjust the microwave power and nitrogen flow rate based on online aldehyde detection data.

[0017] Preferably, the purified product is flash-evaporated to remove residual moisture.

[0018] The beneficial effects of this invention are: the aldehyde value is stably reduced to below 0.005%, which greatly improves the molecular sieve regeneration efficiency; nitrogen sealing dead zone is eliminated and inert gas consumption is greatly reduced; the secondary capture rate of escaped aldehydes is improved; adaptive optimization is achieved and manual intervention is reduced. Attached Figure Description

[0019] Figure 1 This is a structural diagram of the purification system of the present invention.

[0020] Figure 2 This is a schematic diagram of the purification method steps of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but the implementation of the present invention is not limited thereto.

[0022] like Figure 1As shown, the low aldehyde value purification system for fatty alcohol polyoxyethylene ether coupled with nitrogen sealing using molecular sieves is characterized by comprising a molecular sieve unit, a nitrogen sealing unit, a control unit, a microwave regeneration module, a vortex generator, and a Pd-Ag alloy catalytic trap; the control unit integrates an AI algorithm to dynamically adjust the microwave power and nitrogen flow rate based on online aldehyde value detection data, achieving adaptive optimization and reducing manual intervention;

[0023] The molecular sieve unit uses a ZSM-5 type modified molecular sieve with a surface coating of Co-Mn catalyst, with a coating thickness of 5-10 μm, which improves the selectivity of aldehyde adsorption; the adsorption capacity is increased by 40%, and the saturation period is extended to 120 minutes.

[0024] The nitrogen sealing unit includes an inert gas supply device and a pressure regulating device based on differential pressure feedback; the inert gas supply device outputs 99.99% high-purity nitrogen, and the differential pressure feedback pressure regulating device maintains 1.5±0.1 atm to prevent oxygen permeation in dead zones;

[0025] The control unit includes a temperature sensor and an automatic regulating valve, which regulates the temperature to 60±5℃ to prevent thermal degradation.

[0026] The microwave regeneration module periodically irradiates the molecular sieve unit at a frequency of 2.45 GHz; the activation cycle of the microwave regeneration module is irradiation for 10 minutes every 2 hours of operation, with a power density of 50 W / cm³. 2 This results in a molecular sieve adsorption capacity decay rate of ≤5% / week, and energy consumption of only 1 / 3 of that of traditional heating.

[0027] The nitrogen sealing unit outlet is equipped with a vortex generator to form an annular nitrogen curtain covering the surface of the molecular sieve. The nitrogen flow rate gradient of the vortex generator is: 2.5±0.2L / min in the central region and 1.2±0.1L / min in the edge region, forming an annular nitrogen curtain covering the surface of the molecular sieve, thereby eliminating nitrogen sealing dead zones and reducing inert gas consumption by 30%.

[0028] The system integrates a Pd-Ag alloy catalytic trap at the end, with a mesh density of 200 mesh and a Pd / Ag mass ratio of 1:3, achieving a secondary capture rate of ≥99.2% for escaped aldehydes.

[0029] With this purification system setup, the aldehyde value is stably reduced to below 0.005%, greatly improving the molecular sieve regeneration efficiency.

[0030] The system operating conditions set in this embodiment are as follows:

[0031] Ingredients: C 12 -C 14 Fatty alcohol polyoxyethylene ether, initial aldehyde value 0.12%.

[0032] Parameters: Temperature 60℃, pressure 1.5 atm, nitrogen flow rate gradient (center 2.5 L / min, edge 1.2 L / min).

[0033] Catalytic trap: 200 mesh Pd-Ag mesh (Pd / Ag = 1:3), temperature 80℃.

[0034] The synergistic regeneration effect of hydrogen: During microwave regeneration, 5% hydrogen is injected to convert adsorbed aldehydes into alcohols. The reaction formula is: R-CHO + H2 → R-CH2OH.

[0035] Optimized flash dehydration: flash temperature 110℃, pressure 0.01MPa, residual moisture ≤0.008%.

[0036] like Figure 2 As shown, the method for purifying low aldehyde values ​​of fatty alcohol polyoxyethylene ethers using molecular sieve-coupled nitrogen sealing, based on a molecular sieve-coupled nitrogen sealing system for purifying low aldehyde values ​​of fatty alcohol polyoxyethylene ethers, achieves a purified aldehyde value ≤0.005% and reduces energy consumption by 35%. The method specifically includes the following steps:

[0037] (a) The raw material is preheated to 60±5℃ and then passed into the molecular sieve unit;

[0038] (b) The nitrogen sealing unit maintains the system pressure at 1.5±0.1 atm, and the eddy current generator is activated to form an air curtain isolation layer; the nitrogen purity is ≥99.99%, and the oxygen content is ≤10ppm to ensure an oxygen-free environment and prevent oxidation side reactions;

[0039] (c) Trigger microwave regeneration for 10 minutes every 2 hours of operation; during microwave regeneration, hydrogen gas accounting for 5% of the total inert gas is injected simultaneously to reduce the aldehydes to alcohols adsorbed on the surface of the molecular sieve in situ, thereby improving the regeneration efficiency.

[0040] (d) The product was purified a second time by a Pd-Ag catalytic trap at an operating temperature of 80±5℃. After purification, the product was flash-evaporated to remove residual moisture, further reducing the aldehyde value and improving product stability.

[0041] The above embodiments illustrate only one implementation of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A molecular sieve-coupled nitrogen-sealed purification system for low-aldehyde-value fatty alcohol polyoxyethylene ethers, characterized in that, Includes molecular sieve unit, nitrogen sealing unit, control unit, microwave regeneration module, eddy current generator, and Pd-Ag alloy catalyst trap; The molecular sieve unit uses a ZSM-5 type modified molecular sieve with a surface coated with a Co-Mn catalyst; The nitrogen sealing unit includes an inert gas supply device and a pressure regulating device based on differential pressure feedback; The control unit includes a temperature sensor and an automatic regulating valve; The microwave regeneration module periodically irradiates the molecular sieve unit at a frequency of 2.45 GHz; The nitrogen sealing unit outlet is equipped with a vortex generator to form an annular nitrogen curtain covering the surface of the molecular sieve. The system terminal integrates a Pd-Ag alloy catalytic trap.

2. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 1, characterized in that, The nitrogen flow velocity gradient of the vortex generator is: 2.5±0.2 L / min in the central region and 1.2±0.1 L / min in the edge region.

3. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 1, characterized in that, The activation cycle of the microwave regeneration module is 10 minutes of irradiation every 2 hours of operation, with a power density of 50 W / cm². 2 .

4. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 1, characterized in that, The Pd-Ag alloy catalytic trap has a mesh density of 200 mesh and a Pd / Ag mass ratio of 1:

3.

5. A method for purifying low aldehyde values ​​of fatty alcohol polyoxyethylene ethers using molecular sieve coupling and nitrogen sealing, characterized in that, Based on the system according to any one of claims 1-4, the system comprises the following steps: (a) The raw material is preheated to 60±5℃ and then passed into the molecular sieve unit; (b) The nitrogen sealing unit maintains the system pressure at 1.5 ± 0.1 atm, and the eddy current generator is activated to form an air curtain isolation layer; (c) Trigger microwave regeneration for 10 minutes every 2 hours of operation; (d) The product was purified a second time using a Pd-Ag catalytic trap.

6. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 5, characterized in that, In step (b), the nitrogen purity is ≥99.99% and the oxygen content is ≤10ppm.

7. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 5, characterized in that, During microwave regeneration, hydrogen gas, accounting for 5% of the total inert gas, is injected simultaneously to reduce aldehydes and alcohols adsorbed on the surface of the molecular sieve in situ.

8. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 5, characterized in that, The operating temperature of the Pd-Ag catalytic trap is 80±5℃.

9. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 1, characterized in that, The control unit integrates AI algorithms to dynamically adjust microwave power and nitrogen flow rate based on online aldehyde detection data.

10. The molecular sieve-coupled nitrogen-sealed low aldehyde value purification system for fatty alcohol polyoxyethylene ethers according to claim 5, characterized in that, The purified product was then flash-evaporated to remove residual moisture.

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