A process for the production of fatty alcohol polyoxyethylene polyoxypropylene ether

Abstract

The present application belongs to the technical field of non-ionic surfactant synthesis, and particularly relates to a production process of fatty alcohol polyoxyethylene ether polyoxypropylene ether. The present application adopts a supported ternary double-metal composite catalyst, and combines with a segmented temperature control addition process, so that the product has a narrow molecular weight distribution of 1.05-1.08, low unsaturation, and a colority APHA of less than or equal to 7, and the quality is better than that of the KOH and DMC processes. The catalyst is efficiently recycled through ceramic membrane separation and low-temperature activation, the separation efficiency is greater than or equal to 99.5%, and the activity retention rate is greater than or equal to 90% after 5 cycles. A salt-free refining route of modified attapulgite physical decolorization and weak acid cation resin alkali removal is adopted, and the whole process is free of neutralization and salt production, and the three-waste emissions are reduced by more than 90%. The process is precisely closed-loop controlled by DCS, and is mild and safe in reaction, so that a green technology closed loop of efficient catalysis, circulation and salt-free refining is formed, and the present application has outstanding industrialization value.

Description

Technical Field

[0001] This invention belongs to the field of nonionic surfactant synthesis technology, specifically relating to a production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether. Background Technology

[0002] Fatty alcohol polyoxyethylene ether polyoxypropylene ether is a nonionic surfactant obtained by block addition reaction of fatty alcohol with ethylene oxide (EO) and propylene oxide (PO). The hydrophilic-lipophilic balance value can be controlled by adjusting the EO / PO molar ratio, and it is widely used in daily chemical, textile, petrochemical, coating and other fields.

[0003] Currently, there are two major defects in industrial production: (1) Shortcomings in the catalyst system. Traditional processes use alkali metal hydroxides such as KOH as homogeneous catalysts, which require neutralization and filtration to remove alkaline substances, resulting in a large amount of saline wastewater, low product yield, and easy initiation of isomerization side reactions, leading to high product unsaturation and wide molecular weight distribution. Although bimetallic cyanide (DMC) catalysts have high activity and low unsaturation, they have problems such as complex preparation, high cost, large restrictions on initiators, residual metals that easily generate impurities and odors, and affect product stability. (2) Poor process adaptability and backward refining process. Existing processes are not designed to match the characteristics of catalysts, making it difficult to suppress side reactions and resulting in poor batch stability; refining often uses neutralization and desalination, hydrogen peroxide or activated carbon decolorization, generating wastewater and waste residue, which easily causes the product color to deepen and impurities to be not completely removed. The whole process has not formed a green closed loop, with high emissions of waste, poor economic efficiency, and does not meet the requirements of green and low-carbon development.

[0004] To address the aforementioned issues, this invention innovates from two dimensions: catalyst design and process adaptation, providing a highly active, recyclable, salt-free, refined, and stable production process for fatty alcohol polyoxyethylene ether and polyoxypropylene ether. Summary of the Invention

[0005] The purpose of this invention is to address the existing problems by providing a production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether.

[0006] This invention is achieved through the following technical solution:

[0007] A production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether includes the following steps:

[0008] S1. Raw material pretreatment:

[0009] C12~C18 fatty alcohols are dehydrated to a moisture content of ≤0.03wt% after precision filtration. Ethylene oxide and propylene oxide are dried to a moisture content of ≤0.02wt% and then sent to nitrogen-sealed storage tanks for later use.

[0010] S2, segmented temperature-controlled addition reaction:

[0011] A supported ternary bimetallic composite catalyst was added to a reactor and activated. Then, pretreated fatty alcohol was added to the reactor, followed by the introduction of ethylene oxide for reaction. After the ethylene oxide reaction was complete, propylene oxide was added and the reaction was continued to obtain the crude product.

[0012] S3, Salt-free Refined:

[0013] After filtering the crude product, it is first physically decolorized using a modified attapulgite decolorizing agent.

[0014] The product is then subjected to deep dealkalization through a fixed bed of weakly acidic cation exchange resin to achieve a pH value of 6.5-7.0, thus obtaining a purified product.

[0015] S4. Filling and warehousing:

[0016] The refined product is filled under nitrogen protection and then stored in nitrogen-sealed finished product tanks.

[0017] Furthermore, the precision filtration in step S1 has a filtration accuracy of 0.2 μm, and the fatty alcohol dehydration conditions are a vacuum of -0.092 to -0.095 MPa, a temperature of 105 to 110 °C, and a dehydration time of 1.5 to 2 h.

[0018] Furthermore, the amount of the supported ternary bimetallic composite catalyst added in step S2 is 2-3% of the mass of the fatty alcohol;

[0019] The preparation of the supported ternary bimetallic composite catalyst includes the following steps:

[0020] (1) γ-Al2O3 (specific surface area 200~300m²) 2 / g, pore size 5~10nm) raw powder is placed in a muffle furnace and calcined at 550~600℃ for 3h to remove surface adsorbed water, impurities and residual carbonates, and restore its high specific surface area and pore structure. After naturally cooling to room temperature, it is passed through a 40~60 mesh sieve for later use.

[0021] (2) Weigh magnesium nitrate, zinc nitrate and lanthanum nitrate respectively, dissolve them in deionized water, and prepare a mixed precursor solution with a total metal ion concentration of 0.5~0.8 mol / L;

[0022] Based on the mass percentage of each oxide in the final catalyst and using the support mass as a baseline, the loading of MgO is 4-6 wt%, the loading of ZnO is 2-3 wt%, and the loading of La2O3 is 0.5-1 wt%.

[0023] (3) Place the pretreated γ-Al2O3 support in a container, and use the equal volume impregnation method to dropwise add the above-prepared mixed precursor solution. Stir and impregnate at 200-300 rpm for 16-18 h at 20-25℃ to ensure that the metal ions diffuse uniformly and adsorb in the pores of the support to reach saturation equilibrium.

[0024] (4) After impregnation, filter the solid material, place it in an oven, dry it at 110~120℃ for 6 hours, then place it in a muffle furnace and heat it to 500~550℃ at a heating rate of 4~5℃ / min, and keep it heated for 4 hours.

[0025] Further, the activation in step S2 specifically involves: activating at 125~130℃ for 1.5~2h under a nitrogen atmosphere, and then raising the temperature to 138~140℃ for later use.

[0026] Further, in step S2, the molar ratio of the fatty alcohol to ethylene oxide and propylene oxide is 1:(2~8):(1~4);

[0027] Ethylene oxide is introduced and reacted at a temperature of 135~145℃ and a pressure of 0.15~0.25MPa;

[0028] Add propylene oxide and react at a temperature of 150~160℃ and a pressure of 0.2~0.35MPa.

[0029] Furthermore, the segmented temperature-controlled addition reaction in step S2 is controlled by a DCS system with closed-loop control, and the control accuracy is ±0.5℃ for temperature and ±0.005MPa for pressure.

[0030] Further, the filtration in step S3 specifically involves: cooling the crude product to 85-90°C in a nitrogen atmosphere, separating the catalyst through a cross-flow filtration process using a ceramic membrane, purging the separated catalyst with nitrogen, activating it at a low temperature of 120-125°C in a nitrogen atmosphere, and then recycling it; the filtered crude product then proceeds to subsequent processing.

[0031] Furthermore, the ceramic membrane has a filtration accuracy of 0.1 μm and is made of alumina or zirconium oxide.

[0032] Further, the preparation method of the modified attapulgite decolorizing agent in step S3 is as follows: attapulgite is crushed and passed through a 200-mesh sieve, soaked in 1-2 mol / L hydrochloric acid solution for 2-3 hours, washed with water until neutral, dried at 100-120℃ for 3-5 hours, and then calcined at 400-500℃ for 2-3 hours. After cooling, it is obtained.

[0033] The physical decolorization process is carried out at a temperature of 80-85°C, and the amount of decolorizing agent used is 0.8-1.5% of the mass of the crude product.

[0034] Furthermore, the weakly acidic cation exchange resin mentioned in step S3 is a macroporous acrylic cation exchange resin, the volume ratio of resin to product is 1:(3~8), and the space velocity is controlled at 1~2 h⁻¹. -1 Operating pressure ≤0.1MPa.

[0035] The present invention has the following advantages over the prior art:

[0036] 1. This invention employs a ternary composite supported catalyst of MgO-ZnO-La2O3 / γ-Al2O3, combined with a segmented temperature-controlled addition process, to significantly improve product performance. The product has a narrow molecular weight distribution of 1.05~1.08, low unsaturation, APHA color ≤7, and extremely low residual monomer and metal ion content. Its quality is significantly superior to traditional KOH and DMC processes, meeting the requirements for highly consistent surfactants in high-end daily chemical and fine chemical industries.

[0037] 2. This invention achieves efficient catalyst recovery and recycling through ceramic membrane separation and low-temperature activation, with a separation efficiency of ≥99.5%. The catalyst retains ≥90% of its activity after five cycles, significantly reducing catalyst consumption and production energy consumption. Simultaneously, it employs a salt-free refining route using modified attapulgite clay for physical decolorization and weakly acidic cation exchange resin for alkali removal. The entire process involves no neutralization and no salt production, reducing waste emissions by over 90% compared to traditional processes, thus combining low cost with environmental friendliness.

[0038] 3. The entire process of this invention is precisely controlled in a closed loop by a DCS system, ensuring mild reaction conditions and stable parameters. Key processes are equipped with automatic interlocking protection, significantly improving the operational safety of hazardous processes. The entire process forms a complete green technology closed loop encompassing efficient catalysis, catalyst recycling, and salt-free refining, achieving significant breakthroughs in product quality, production costs, environmental protection, and safety, and possessing outstanding value for industrial application. Attached Figure Description

[0039] Figure 1 The graph shows the yield comparison results of each embodiment and comparative example product. Detailed Implementation

[0040] To further explain the present invention, the following specific embodiments are described.

[0041] Example 1

[0042] A production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether includes the following steps:

[0043] S1. Raw material pretreatment:

[0044] The C14-C16 mixed fatty alcohols were filtered through a 0.2μm precision filter and then sent to a vacuum dehydration reactor for dehydration at a vacuum of -0.092MPa and a temperature of 105℃ for 2 hours. The moisture content was found to be 0.025wt%.

[0045] Ethylene oxide and propylene oxide are dried to a moisture content of 0.015 wt% using 4A molecular sieves and then stored in nitrogen-sealed tanks for later use.

[0046] S2, Catalyst Preparation

[0047] (1) γ-Al2O3 (specific surface area 200~300m²) 2 / g, pore size 5~10nm) raw powder is placed in a muffle furnace and calcined at 550℃ for 3h to remove surface adsorbed water, impurities and residual carbonates, and restore its high specific surface area and pore structure. After naturally cooling to room temperature, it is passed through a 40~60 mesh sieve for later use.

[0048] (2) Weigh magnesium nitrate, zinc nitrate and lanthanum nitrate respectively, dissolve them in deionized water, and prepare a mixed precursor solution with a total metal ion concentration of 0.5 mol / L;

[0049] Based on the mass percentage of each oxide in the final catalyst, and taking the support mass as a baseline, the loading of MgO was 4 wt%, the loading of ZnO was 2 wt%, and the loading of La2O3 was 0.5 wt%.

[0050] (3) Place the pretreated γ-Al2O3 support in a container, and use the equal volume impregnation method to drop the above-prepared mixed precursor solution. Stir and impregnate at 200 rpm for 18 h at 20℃ to ensure that the metal ions diffuse uniformly and adsorb into the pores of the support, and reach saturation equilibrium.

[0051] (4) After impregnation, the solid material is filtered and placed in an oven. After drying at 110°C for 6 hours, it is placed in a muffle furnace and heated to 500°C at a heating rate of 4°C / min. It is then kept at the temperature for 4 hours.

[0052] S3, Catalyst activation:

[0053] The supported ternary bimetallic composite catalyst was added to the reactor at 2% of the fatty alcohol mass, and high-purity nitrogen was introduced to replace the oxygen content until it was ≤0.08%. It was activated at 125℃ for 2 hours under a nitrogen atmosphere, and then the temperature was raised to 138℃ for later use.

[0054] S4, segmented temperature-controlled addition reaction:

[0055] Pretreated fatty alcohol was added to the reactor. The molar ratio of fatty alcohol to ethylene oxide and propylene oxide was 1:2:1. Ethylene oxide was first introduced and reacted at a temperature of 135℃ and a pressure of 0.15MPa at a rate of 28kg / h. The reaction was maintained at this temperature for 0.9h until the pressure dropped to atmospheric pressure. Then propylene oxide was added and reacted at a temperature of 150℃ and a pressure of 0.2MPa at a rate of 22kg / h. The reaction was maintained at this temperature for 1.1h to obtain the crude product.

[0056] S5. Catalyst recovery:

[0057] The crude product was cooled to 85°C in a nitrogen atmosphere and the catalyst was separated by cross-flow filtration through a 0.1μm alumina ceramic membrane. The separated catalyst was purged with nitrogen, activated at 120°C in a nitrogen atmosphere, and then recycled. The filtered crude product was sent to a refining reactor.

[0058] S6, Salt-free refined:

[0059] Add 0.8% of the crude product mass of modified attapulgite decolorizing agent to the refining kettle and decolorize at 80℃ and 380rpm for 32min. Remove the decolorizing agent by plate and frame filtration.

[0060] The decolorized product was passed through a fixed bed of D113 macroporous acrylic cation exchange resin (resin to product volume ratio 1:3, space velocity controlled at 1 h⁻¹). -1 The operating pressure was 0.08 MPa, and the pH of the outlet product was 6.5, yielding a purified product.

[0061] The modified attapulgite decolorizing agent is prepared by crushing attapulgite through a 200-mesh sieve, soaking it in a 1mol / L hydrochloric acid solution for 3 hours, washing it with water until neutral, drying it at 100℃ for 5 hours, calcining it at 400℃ for 3 hours, and then cooling it to obtain the product.

[0062] S7. Filling and warehousing:

[0063] The refined product is filled under nitrogen protection and then stored in nitrogen-sealed finished product tanks.

[0064] Example 2

[0065] A production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether includes the following steps:

[0066] S1. Raw material pretreatment:

[0067] The C14-C16 mixed fatty alcohols were filtered through a 0.2μm precision filter and then fed into a vacuum dehydration reactor. Dehydration was carried out at a vacuum of -0.093MPa and a temperature of 108℃ for 1.8 hours, and the moisture content was determined to be 0.025wt%.

[0068] Ethylene oxide and propylene oxide are dried to a moisture content of 0.015 wt% using 4A molecular sieves and then stored in nitrogen-sealed tanks for later use.

[0069] S2, Catalyst Preparation

[0070] (1) γ-Al2O3 (specific surface area 200~300m²) 2 / g, pore size 5~10nm) raw powder is placed in a muffle furnace and calcined at 580℃ for 3h to remove surface adsorbed water, impurities and residual carbonates, and restore its high specific surface area and pore structure. After naturally cooling to room temperature, it is passed through a 40~60 mesh sieve for later use.

[0071] (2) Weigh magnesium nitrate, zinc nitrate and lanthanum nitrate respectively, dissolve them in deionized water, and prepare a mixed precursor solution with a total metal ion concentration of 0.6 mol / L;

[0072] Based on the mass percentage of each oxide in the final catalyst, and taking the support mass as a baseline, the loading of MgO was 5 wt%, the loading of ZnO was 2.5 wt%, and the loading of La2O3 was 0.8 wt%.

[0073] (3) Place the pretreated γ-Al2O3 support in a container, and use the equal volume impregnation method to drop the above-prepared mixed precursor solution. Stir and impregnate at 250 rpm for 17 h at 22℃ to ensure that the metal ions diffuse uniformly and adsorb into the pores of the support to reach saturation equilibrium.

[0074] (4) After impregnation, the solid material is filtered and placed in an oven. After drying at 115°C for 6 hours, it is placed in a muffle furnace and heated to 520°C at a heating rate of 4.5°C / min. It is then kept at the temperature for 4 hours.

[0075] S3, Catalyst activation:

[0076] The supported ternary bimetallic composite catalyst was added to the reactor at 2.5% of the fatty alcohol mass, and high-purity nitrogen was introduced to replace the oxygen content until it was ≤0.08%. The catalyst was activated at 128℃ for 1.8h under a nitrogen atmosphere, and then heated to 139℃ for later use.

[0077] S4, segmented temperature-controlled addition reaction:

[0078] Pretreated fatty alcohol was added to the reactor. The molar ratio of fatty alcohol to ethylene oxide and propylene oxide was 1:5:3. Ethylene oxide was first introduced and reacted at a temperature of 140℃ and a pressure of 0.20MPa at a rate of 28kg / h. The reaction was maintained at this temperature for 0.9h until the pressure dropped to atmospheric pressure. Then propylene oxide was added and reacted at a temperature of 155℃ and a pressure of 0.28MPa at a rate of 22kg / h. The reaction was maintained at this temperature for 1.1h to obtain the crude product.

[0079] S5. Catalyst recovery:

[0080] The crude product was cooled to 88°C in a nitrogen atmosphere and the catalyst was separated by cross-flow filtration through a 0.1μm alumina ceramic membrane. The separated catalyst was purged with nitrogen, activated at 123°C in a nitrogen atmosphere, and then recycled. The filtered crude product was sent to a refining reactor.

[0081] S6, Salt-free refined:

[0082] Add 1.2% of the crude product mass of modified attapulgite decolorizing agent to the refining kettle and decolorize at 83℃ and 380rpm for 32min. Remove the decolorizing agent by plate and frame filtration.

[0083] The decolorized product was passed through a fixed bed of D113 macroporous acrylic cation exchange resin (resin to product volume ratio 1:5, space velocity controlled at 1.5 h⁻¹). -1 The operating pressure was 0.08 MPa, and the pH of the outlet product was 6.8, yielding a purified product.

[0084] The modified attapulgite decolorizing agent is prepared by crushing attapulgite through a 200-mesh sieve, soaking it in a 1.5 mol / L hydrochloric acid solution for 2.5 h, washing it with water until neutral, drying it at 110 °C for 4 h, calcining it at 450 °C for 2.5 h, and cooling it to obtain the product.

[0085] S7. Filling and warehousing:

[0086] The refined product is filled under nitrogen protection and then stored in nitrogen-sealed finished product tanks.

[0087] Example 3

[0088] A production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether includes the following steps:

[0089] S1. Raw material pretreatment:

[0090] The C14-C16 mixed fatty alcohols were filtered through a 0.2μm precision filter and then fed into a vacuum dehydration reactor. Dehydration was carried out at a vacuum of -0.095MPa and a temperature of 110℃ for 1.5 hours, and the moisture content was determined to be 0.025wt%.

[0091] Ethylene oxide and propylene oxide are dried to a moisture content of 0.015 wt% using 4A molecular sieves and then stored in nitrogen-sealed tanks for later use.

[0092] S2, Catalyst Preparation

[0093] (1) γ-Al2O3 (specific surface area 200~300m²) 2 / g, pore size 5~10nm) raw powder is placed in a muffle furnace and calcined at 600℃ for 3h to remove surface adsorbed water, impurities and residual carbonates, and restore its high specific surface area and pore structure. After naturally cooling to room temperature, it is passed through a 40~60 mesh sieve for later use.

[0094] (2) Weigh magnesium nitrate, zinc nitrate and lanthanum nitrate respectively, dissolve them in deionized water, and prepare a mixed precursor solution with a total metal ion concentration of 0.8 mol / L;

[0095] Based on the mass percentage of each oxide in the final catalyst, and taking the support mass as a baseline, the loading of MgO was 6 wt%, the loading of ZnO was 3 wt%, and the loading of La2O3 was 1 wt%.

[0096] (3) Place the pretreated γ-Al2O3 support in a container, and use the equal volume impregnation method to dropwise add the above-prepared mixed precursor solution. Stir and impregnate at 300 rpm for 16 h at 25 °C to ensure that the metal ions diffuse uniformly and adsorb into the pores of the support, and reach saturation equilibrium.

[0097] (4) After impregnation, the solid material is filtered and placed in an oven. After drying at 120°C for 6 hours, it is placed in a muffle furnace and heated to 550°C at a heating rate of 5°C / min. It is then kept at the temperature for 4 hours.

[0098] S3, Catalyst activation:

[0099] The supported ternary bimetallic composite catalyst was added to the reactor at 3% by mass of fatty alcohol, and high-purity nitrogen was introduced to replace the oxygen content until it was ≤0.08%. It was activated at 130℃ for 1.5h under nitrogen atmosphere, and then heated to 140℃ for later use.

[0100] S4, segmented temperature-controlled addition reaction:

[0101] Pretreated fatty alcohol was added to the reactor. The molar ratio of fatty alcohol to ethylene oxide and propylene oxide was 1:8:4. Ethylene oxide was first introduced and reacted at a temperature of 145℃ and a pressure of 0.25MPa at a rate of 28kg / h. The reaction was maintained at this temperature for 0.9h until the pressure dropped to atmospheric pressure. Then propylene oxide was added and reacted at a temperature of 160℃ and a pressure of 0.35MPa at a rate of 22kg / h. The reaction was maintained at this temperature for 1.1h to obtain the crude product.

[0102] S5. Catalyst recovery:

[0103] The crude product was cooled to 90°C in a nitrogen atmosphere and the catalyst was separated by cross-flow filtration through a 0.1μm alumina ceramic membrane. The separated catalyst was purged with nitrogen, activated at 125°C in a nitrogen atmosphere, and then recycled. The filtered crude product was sent to a refining reactor.

[0104] S6, Salt-free refined:

[0105] Add 1.5% of the crude product mass of modified attapulgite decolorizing agent to the refining kettle and decolorize at 85℃ and 380rpm for 32min. Remove the decolorizing agent by plate and frame filtration.

[0106] The decolorized product was passed through a fixed bed of D113 macroporous acrylic cation exchange resin (resin to product volume ratio 1:8, space velocity controlled at 2 h⁻¹). -1 The operating pressure was 0.08 MPa, and the pH of the outlet product was 7.0, resulting in a purified product.

[0107] The modified attapulgite decolorizing agent is prepared by crushing attapulgite through a 200-mesh sieve, soaking it in a 2 mol / L hydrochloric acid solution for 2 hours, washing it with water until neutral, drying it at 120°C for 3 hours, calcining it at 500°C for 2 hours, and then cooling it to obtain the product.

[0108] S7. Filling and warehousing:

[0109] The refined product is filled under nitrogen protection and then stored in nitrogen-sealed finished product tanks.

[0110] Comparative Example 1: Traditional Craftsmanship

[0111] Based on Example 2, keeping the same fatty alcohol type, ethylene oxide / propylene oxide molar ratio (1:5:3), and feed amount, but using a conventional homogeneous base catalyst and conventional refining process, the specific steps are as follows:

[0112] S1. Raw material pretreatment: Same as in Example 2.

[0113] S2. Catalytic reaction: KOH was used as a catalyst, and the amount added was 0.3% of the mass of the fatty alcohol (calculated as KOH). KOH was dissolved in the fatty alcohol, and the mixture was heated to 140℃ and vacuum dehydrated until the water content was ≤0.03%. Then, ethylene oxide and propylene oxide were mixed in proportion and introduced into the reaction in one step at a temperature of 140℃ and a pressure of 0.25MPa (mixing and introducing rate of 50kg / h). The reaction was maintained at this temperature for 2h to obtain the crude product.

[0114] S3, Neutralization and Decolorization: Cool the crude product to 85℃, add phosphoric acid to neutralize to pH≈7, filter to remove potassium phosphate, add 1.0% hydrogen peroxide (30% concentration) of crude product mass to the filtrate, keep at 80℃ for oxidation and decolorization for 30 min, and then add 1.0% activated carbon for adsorption and filtration.

[0115] S4. Refining: The decolorized product is directly dehydrated under reduced pressure (vacuum degree -0.095MPa, 105℃) to a moisture content ≤0.1% without ion exchange resin treatment;

[0116] S5. Filling: Same as in Example 2.

[0117] Comparative Example 2: Non-segmented temperature control + no deep dealkali removal

[0118] Based on Example 2, the same supported ternary bimetallic composite catalyst was used, but the reaction was carried out in a one-step isothermal and isobaric process, and the purification step omitted the weakly acidic cation exchange resin fixed bed, and only modified attapulgite was used for decolorization.

[0119] The specific steps are as follows:

[0120] S1. Raw material pretreatment: Same as in Example 2;

[0121] S2. Catalyst preparation and activation: Same as in Example 2;

[0122] S3. One-step addition reaction: Add fatty alcohol to the reactor, activate the catalyst, mix ethylene oxide and propylene oxide in a molar ratio of 5:3, and introduce them in one go at a temperature of 145℃ and a pressure of 0.28MPa (introduction rate of 50kg / h). Keep the reaction at this temperature for 2h to obtain the crude product.

[0123] S4. Catalyst recovery: Same as in Example 2 (ceramic membrane cross-flow filtration);

[0124] S5. Salt-free refining: The crude product is decolorized with modified attapulgite clay only (same as in Example 2, dosage 1.2%, 83°C), and after plate and frame filtration, it is directly sent to the finished product tank without passing through the ion exchange resin fixed bed.

[0125] S6. Filling: Same as in Example 2.

[0126] 1. Basic Physicochemical Indicators Test

[0127] Product color (APHA): Platinum-cobalt colorimetric method;

[0128] Moisture content: Karl Fischer method.

[0129] The test results are shown in Table 1 below.

[0130] Table 1. Basic physicochemical properties of each embodiment and comparative sample.

[0131] Example 1 Colorless and transparent 22 0.05 Example 2 Colorless and transparent 18 0.04 Example 3 Colorless and transparent 20 0.04 Comparative Example 1 pale yellow and transparent 85 0.12 Comparative Example 2 pale yellow and transparent 52 0.06

[0132] As shown in Table 1 above, the color of Examples 1-3 is ≤22 APHA, which is far superior to Comparative Example 1 (85) and Comparative Example 2 (52). This is because the present invention uses a supported ternary bimetallic composite catalyst, which has a mild reaction and few side reactions, avoiding oxidation and discoloration caused by strong base catalysis. In addition, the purification process uses modified attapulgite clay for physical decolorization, which does not introduce oxidants and does not damage the polyether chain; it is combined with a weakly acidic cation exchange resin to remove trace metal ions and prevent catalytic oxidation during storage. Comparative Example 1 uses hydrogen peroxide + activated carbon. Hydrogen peroxide may cause polyether chain breakage and carbonyl generation at 80°C, resulting in a darker color; the activated carbon filtration is not thorough, and the residual carbon powder affects the transparency. Comparative Example 2 omits the ion exchange resin, and the residual metal ions promote subsequent oxidation, resulting in a higher color than the examples.

[0133] The moisture content in Examples 1-3 was ≤0.05%, while that in Comparative Example 1 was as high as 0.12%. The Examples used precision dehydration and nitrogen sealing for storage, and the fixed bed of ion exchange resin operated at low pressure, thus not introducing water. In contrast, Comparative Example 1 introduced water through neutralization, decolorization, and activated carbon filtration, and the depressurization dehydration was incomplete.

[0134] All examples are colorless and transparent, while the comparative examples are pale yellow or slightly yellow, consistent with the color data.

[0135] 2. Molecular weight, distribution, and residual monomers

[0136] Molecular weight and distribution (Mw / Mn): Gel permeation chromatography (GPC);

[0137] Residual ethylene oxide / propylene oxide: headspace gas chromatography.

[0138] The test results are shown in Table 2 below.

[0139] Table 2. Molecular weight, distribution, and residual monomers of each example and comparative sample.

[0140] Example 1 620 1.05 Not detected (<1) Example 2 1280 1.06 Not detected (<1) Example 3 1980 1.07 Not detected (<1) Comparative Example 1 1190 1.32 23 Comparative Example 2 1250 1.18 8

[0141] As shown in Table 2 above, the distribution width of Examples 1-3 is only 1.05-1.07, which is extremely narrow. This indicates that the segmented temperature-controlled addition (EO first, then PO, with separate temperature and pressure control) combined with high-precision DCS control results in uniform chain growth and fewer side reactions. Comparative Example 1 uses KOH homogeneous catalysis + one-step mixed feed, and the large difference in the polymerization reactivity rates of EO and PO leads to a distribution width of 1.32. Although Comparative Example 2 uses the same catalyst, it does not have segmented temperature control, and the distribution is still relatively wide (1.18). This proves that segmented temperature control is the key to a narrow distribution.

[0142] The examples showed no detectable levels (<1 ppm), while Comparative Example 1 showed 23 ppm of residue, and Comparative Example 2 showed 8 ppm of residue. The examples demonstrated high reaction completeness: the EO stage reaction continued until the pressure dropped to atmospheric pressure before PO was added, ensuring complete reaction in each stage; precise DCS control prevented monomer escape due to over-temperature and over-pressure. Comparative Example 1, with its one-step mixed feed method, experienced incomplete monomer competition reaction; Comparative Example 2, with its one-step method, also exhibited this problem.

[0143] Example 1 (EO:PO=2:1) ​​Mn=620, Example 2 (5:3) Mn=1280, Example 3 (8:4) Mn=1980, demonstrating that the molecular weight of the product can be precisely controlled by adjusting the monomer ratio, and the distribution does not become significantly wider with the increase of molecular weight, indicating good process universality.

[0144] 3. Surface properties

[0145] Cloud spot: Visual inspection;

[0146] Surface tension: Platinum plate method.

[0147] The test results are shown in Table 3 below.

[0148] Table 3 Surface properties of samples from various examples and comparative examples

[0149] Example 1 42.5 32.8 Example 2 68.5 31.2 Example 3 86.0 30.5 Comparative Example 1 62.3 33.8 Comparative Example 2 66.0 32.5

[0150] As shown in Table 3 above, the cloud point increases with increasing EO ratio, consistent with the behavior of nonionic surfactants. The cloud point of Comparative Example 1 (62.3℃) is lower than that of Example 2 (68.5℃) because it has a wider molecular weight distribution, contains more low-EO chain segment components, and has insufficient hydrophilicity; at the same time, residual metal ions may affect micelle behavior. The cloud point of Comparative Example 2 (66.0℃) is still lower than that of Example 2, due to its wider distribution and higher pH (8.5), which leads to a decrease in cloud point.

[0151] Example 3 had the lowest surface tension (30.5 mN / m), followed by Example 2 (31.2), and Example 1 had the highest (32.8). Increased molecular weight and longer EO chains resulted in a better balance between hydrophobic and hydrophilic chains, leading to enhanced surface activity. Comparative Example 1 had the highest surface tension (33.8) due to its wide distribution containing low-activity components; Comparative Example 2 (32.5) was slightly higher than Example 2 because its wide distribution and lack of alkali removal resulted in slightly poorer interfacial performance.

[0152] 4. Residual metal ions

[0153] Metal ions: Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES).

[0154] The test results are shown in Table 4 below.

[0155] Table 4. Metal ion residues (mg / kg) in each example and comparative sample.

[0156] Example 1 - 1.8 1.2 0.6 Example 2 - 2.1 1.5 0.8 Example 3 - 2.3 1.7 0.9 Comparative Example 1 85 - - - Comparative Example 2 - 2.3 1.6 0.9

[0157] Note: "-" indicates that the element was not detected or was not used.

[0158] As shown in Table 4 above, Mg in Examples 1-3 2+ Zn 2+ La 3+ Extremely low residue (≤2.3 mg / kg), ceramic membrane cross-flow filtration efficiently recovers the catalyst, and catalyst particles in the filtrate are almost completely removed. The weakly acidic cation exchange resin (D113) has a strong adsorption capacity for multivalent metal ions, achieving deep dealkali removal.

[0159] Comparative Example 1 used a homogeneous catalyst, KOH, to neutralize potassium phosphate. Filtration was incomplete. + The residue level is as high as 85 mg / kg, which seriously affects the application of the product in high-end fields such as electronics and pharmaceuticals.

[0160] Comparative Example 2 omits ion exchange resin, Mg 2+ Zn 2+ La 3+ The residue is similar to that in the example (because the ceramic membrane has filtered out particles), but there are actually more soluble ions (not adsorbed), which may precipitate or catalytically oxidize during long-term storage. The values ​​in the table are similar because the samples may have been filtered before ICP testing, but the stability is poor in actual applications.

[0161] 5. Catalyst performance

[0162] The test results are shown in Table 5 below.

[0163] Table 5. Catalyst consumption and activity retention rate after 5 cycles for each example and comparative sample.

[0164] Example 1 8.5 91 Example 2 8.5 92 Example 3 8.5 90 Comparative Example 1 32 - Comparative Example 2 8.8 89

[0165] As shown in Table 5 above, the initial addition amount of 8.5 kg / t of product in Examples 1-3 decreased to 2.0-2.3 kg / t after 5 cycles, which is much lower than the 32 kg / t of Comparative Example 1 (which is not recyclable), demonstrating significant economic benefits. The consumption of Comparative Example 2 was slightly higher (8.8 kg / t) because the one-step reaction was incomplete, resulting in slightly greater catalyst loss.

[0166] After 5 cycles in Examples 1-3, the catalyst activity retained ≥90%, indicating good catalyst stability. Comparative Example 2 showed 89%, slightly lower, because the one-step reaction conditions (145℃, 0.28MPa) were more stringent than the segmented temperature control (the PO segment reached a maximum of 160℃ but with pressure matching), resulting in slight catalyst deactivation. The catalyst of this invention exhibits strong resistance to sintering and poisoning through the synergistic effect of MgO, ZnO, and La2O3.

[0167] 6. Product yield

[0168] Test results are as follows Figure 1 As shown.

[0169] Depend on Figure 1 It can be seen that the yields of Examples 1-3 are all ≥97.5%, significantly higher than those of Comparative Example 1 (92.5%) and Comparative Example 2 (95.6%). Example 2 has the highest yield (98.2%), while Example 1's slightly lower yield (97.5%) may be due to a small loss of low molecular weight products during decolorization or filtration. Example 3 (98.0%) has a slightly higher yield due to the large amount of epoxy addition, longer reaction time, and some side reactions. The yield of Comparative Example 2 is 95.6%, which is 2.6 percentage points lower than that of Example 2, indicating that even when using the same catalyst, the one-step method still leads to incomplete monomer reaction and byproduct formation.

[0170] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A production process for fatty alcohol polyoxyethylene ether polyoxypropylene ether, characterized in that, Includes the following steps: S1. Raw material pretreatment: C12~C18 fatty alcohols are dehydrated to a moisture content of ≤0.03wt% after precision filtration. Ethylene oxide and propylene oxide are dried to a moisture content of ≤0.02wt% and then sent to nitrogen-sealed storage tanks for later use. S2, segmented temperature-controlled addition reaction: A supported ternary bimetallic composite catalyst was added to a reactor and activated. Then, pretreated fatty alcohol was added to the reactor, followed by the introduction of ethylene oxide for reaction. After the ethylene oxide reaction was complete, propylene oxide was added and the reaction was continued to obtain the crude product. S3, Salt-free Refined: After filtering the crude product, it is first physically decolorized using a modified attapulgite decolorizing agent. The product is then subjected to deep dealkalization through a fixed bed of weakly acidic cation exchange resin to achieve a pH value of 6.5-7.0, thus obtaining a purified product. S4. Filling and warehousing: The refined product is filled under nitrogen protection and then stored in nitrogen-sealed finished product tanks.

2. The production process according to claim 1, characterized in that, The precision filtration in step S1 has a filtration accuracy of 0.2 μm, and the dehydration conditions for fatty alcohols are a vacuum of -0.092 to -0.095 MPa, a temperature of 105 to 110 °C, and a dehydration time of 1.5 to 2 h.

3. The production process according to claim 1, characterized in that, The amount of the supported ternary bimetallic composite catalyst added in step S2 is 2-3% of the mass of the fatty alcohol; The preparation of the supported ternary bimetallic composite catalyst includes the following steps: (1) Place the γ-Al2O3 raw powder in a muffle furnace and calcine it at 550~600℃ for 3 hours. After cooling it to room temperature naturally, pass it through a 40~60 mesh sieve for later use. (2) Weigh magnesium nitrate, zinc nitrate and lanthanum nitrate respectively, dissolve them in deionized water, and prepare a mixed precursor solution with a total metal ion concentration of 0.5~0.8 mol / L; Based on the mass percentage of each oxide in the final catalyst and using the support mass as a baseline, the loading of MgO is 4-6 wt%, the loading of ZnO is 2-3 wt%, and the loading of La2O3 is 0.5-1 wt%. (3) Place the pretreated γ-Al2O3 support in a container, and use the equal volume impregnation method to dropwise add the above-prepared mixed precursor solution. Stir and impregnate at 200-300 rpm for 16-18 h at 20-25℃. (4) After impregnation, filter the solid material, place it in an oven, dry it at 110~120℃ for 6 hours, then place it in a muffle furnace and heat it to 500~550℃ at a heating rate of 4~5℃ / min, and keep it heated for 4 hours.

4. The production process according to claim 1, characterized in that, The activation described in step S2 is specifically as follows: activating at 125~130℃ for 1.5~2h under a nitrogen atmosphere, and then raising the temperature to 138~140℃ for later use.

5. The production process according to claim 1, characterized in that, The molar ratio of the fatty alcohol to ethylene oxide and propylene oxide in step S2 is 1:(2~8):(1~4); Ethylene oxide is introduced and reacted at a temperature of 135~145℃ and a pressure of 0.15~0.25MPa; Add propylene oxide and react at a temperature of 150~160℃ and a pressure of 0.2~0.35MPa.

6. The production process according to claim 1, characterized in that, The segmented temperature-controlled addition reaction described in step S2 is controlled by a DCS system with closed-loop control, and the control accuracy is ±0.5℃ for temperature and ±0.005MPa for pressure.

7. The production process according to claim 1, characterized in that, The filtration in step S3 specifically involves: cooling the crude product to 85-90°C in a nitrogen atmosphere, separating the catalyst through a cross-flow filtration process using a ceramic membrane, purging the separated catalyst with nitrogen, activating it at a low temperature of 120-125°C in a nitrogen atmosphere, and then recycling it; the filtered crude product then proceeds to subsequent processing.

8. The production process according to claim 7, characterized in that, The ceramic membrane has a filtration accuracy of 0.1 μm and is made of alumina or zirconium oxide.

9. The production process according to claim 1, characterized in that, The preparation method of the modified attapulgite decolorizing agent in step S3 is as follows: attapulgite is crushed and passed through a 200-mesh sieve, soaked in 1-2 mol / L hydrochloric acid solution for 2-3 hours, washed with water until neutral, dried at 100-120℃ for 3-5 hours, and then calcined at 400-500℃ for 2-3 hours. After cooling, the product is obtained. The physical decolorization process involves a decolorization temperature of 80-85°C and a decolorizing agent dosage of 0.8-1.5% of the crude product mass.

10. The production process according to claim 1, characterized in that, The weakly acidic cation exchange resin mentioned in step S3 is a macroporous acrylic cation exchange resin, with a resin-to-product volume ratio of 1:(3~8) and a space velocity controlled at 1~2 h⁻¹. -1 Operating pressure ≤0.1MPa.

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