The invention relates to 1, 1apos; co-production method of-oxydiyl-2-propanol and tripropylene glycol

Abstract

The invention relates to a co-production method of 1, 1 '-oxydi-2-propanol and tripropylene glycol, which comprises the following steps: by taking propylene oxide and propylene glycol as raw materials, carrying out catalytic reaction under the action of a solid base catalyst, and separating and purifying after the reaction to respectively obtain the 1, 1'-oxydi-2-propanol and tripropylene glycol. The technology is flexible, intermittent production can be achieved, continuous operation can also be achieved, and adaptability is high; the content of the product 1, 1 '-oxydi-2-propanol is high, and the subsequent separation and purification process is greatly simplified; after the reaction, the catalyst can be repeatedly used through simple filtration or direct regeneration, no alkali-containing wastewater is generated in the process flow, and the environmental burden is greatly reduced; the obtained single isomer is used as a raw material of polymers such as polyurethane, and can provide highly consistent reaction activity and polymerization kinetics, so that the molecular structure of the polymer is accurately regulated and controlled, the final product is endowed with more excellent and stable mechanical properties, thermal properties and hydrolytic stability, and the application requirements in the high-end field are met.

Description

Technical Field

[0001] This invention belongs to the field of fine chemical and polymer material synthesis technology, specifically relating to a method for the co-production of 1,1'-oxadiyl-2-propanol and tripropylene glycol. Background Technology

[0002] 1,1'-Oxadiyl-2-propanol is one of the major isomers of dipropylene glycol. It is an important chemical raw material and high-end solvent, and is widely used in the synthesis of unsaturated polyester resins, polyurethanes, plasticizers, fragrances, cosmetics and liquid detergents. However, there are currently no commercially available high-concentration 1,1'-oxadiyl-2-propanol products.

[0003] In traditional industry, dipropylene glycol is mainly produced through the hydrolysis of propylene oxide, a process that typically uses liquid alkalis (such as NaOH or KOH) as catalysts. This method has significant drawbacks: firstly, the reaction has poor selectivity, and the products are a complex mixture containing multiple isomers, including 1,1'-oxodim-2-propanol, 2-(2-hydroxypropoxy)-1-propanol, and di(2-hydroxypropyl) ether. Mistex Chemicals tested 50 dipropylene glycol (DPG) samples from several commercially available companies, using mass spectrometry to qualitatively and quantitatively analyze their isomers. The samples included those from Shanghai Xindao Chemical Co., Ltd., Dongguan Heshibi New Materials Co., Ltd., Dow Chemical (China) Co., Ltd., Shanghai Yunran Chemical Co., Ltd., Nanjing Junhe Chemical Co., Ltd., and Shandong Shida Shenghua Chemical Group Co., Ltd. The results showed that all samples contained several DPG isomers, including 1,1'-oxodil-2-propanol, 2-(2-hydroxypropoxy)-1-propanol, di(2-hydroxypropyl) ether, and bis(1-methyl-2-hydroxyethyl) ether. The content of 1,1'-oxodil-2-propanol typically fluctuated between 32% and 62%. This structural uncertainty affects its performance in high-end polymer synthesis, leading to poor polymerization compatibility, wide molecular weight distribution, and inconsistent final product performance. Secondly, the homogeneous alkaline catalysis process involves cumbersome post-treatment, requiring neutralization and water washing, which generates a large amount of saline wastewater, causing serious environmental pollution. Furthermore, the catalyst cannot be recovered, which is inconsistent with the development direction of green chemistry.

[0004] Therefore, developing a highly selective and environmentally friendly clean production process for the synthesis of 1,1'-oxadiyl-2-propanol has significant industrial application value. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing 1,1'-oxadiyl-2-propanol production methods have poor selectivity, serious environmental pollution, and the catalyst cannot be recovered.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for the co-production of 1,1'-oxadiyl-2-propanol and tripropylene glycol involves using propylene oxide and propylene glycol as raw materials, carrying out a catalytic reaction in a reactor under the action of a solid base catalyst, and then separating and purifying the reactants to obtain 1,1'-oxadiyl-2-propanol and tripropylene glycol, respectively.

[0007] The molar ratio of propylene glycol to propylene oxide is 1.2:1 to 5:1. For optimal reaction selectivity and product yield, a preferred molar ratio is 1.5:1 to 2.5:1. The solid base catalyst consists of a basic oxide and a metal salt, forming a dual active center, and is supported on a carrier.

[0008] The alkaline oxide may be selected from: calcium oxide (CaO), magnesium oxide (MgO), potassium oxide (K2O), sodium oxide (Na2O), cesium oxide (Cs2O), etc.

[0009] The metal salt may be selected from: nitrates (such as sodium nitrate, potassium nitrate, calcium nitrate, magnesium nitrate, cesium nitrate), chlorides (such as sodium chloride, calcium chloride, potassium chloride, magnesium chloride, cesium chloride), carbonates (such as potassium carbonate, calcium carbonate, magnesium carbonate, cesium carbonate), etc.

[0010] The preparation method of the solid base catalyst is as follows: 1) Dissolve 5-20 parts by weight of the basic oxide in 50-200 parts by weight of deionized water and stir at 40 ℃~60 ℃ for 10-30 minutes; 2) Add 1-10 parts by weight of metal salt to the solution obtained in step 1) and continue stirring for 20-60 min; 3) Add 70-90 parts by weight of carrier to the mixture obtained in step 2) and stir at the same temperature for 1-4 hours; 4) Aging the slurry obtained in step 3) at 20℃~80℃ for 2~12 h; 5) After aging, filter the filter cake and dry it at 110℃~150℃ to constant weight. 6) Grind the dried solid to 10-60 mesh, place it in a muffle furnace, and calcine it at 400℃-800℃ for 2-6 h to obtain the solid base catalyst.

[0011] Deactivated solid base catalysts can be regenerated by calcining in air at 500-1000℃ for 2-4 hours, and can be reused after their activity is restored.

[0012] This invention can employ two reaction modes: Batch reaction (reactor): The amount of catalyst added is 1% to 10% of the total mass of the raw materials.

[0013] Continuous reaction (fixed-bed reactor): The feedstock is continuously fed into a fixed-bed reactor packed with catalyst. The liquid hourly space velocity (LHSV) is controlled between 0.1 and 2.0 h⁻¹.

[0014] The reaction temperature range is 80-200℃, with a preferred temperature of 120-160℃; the reaction pressure is maintained at 0.3-1.0 MPa.

[0015] After the reaction, the product is purified by conventional separation techniques such as distillation. The main product is 1,1'-oxadiyl-2-propanol with a purity of over 99%, and the byproduct is tripropanediol.

[0016] Raw material recovery: Unreacted propylene glycol is returned to the reaction system for recycling.

[0017] Advantages of this invention:

[0018] Flexible process: It can be produced intermittently or continuously, making it highly adaptable.

[0019] High selectivity: Through specific solid base catalysts and reaction processes, high selectivity of the reaction is achieved, and the product 1,1'-oxadiyl-2-propanol has a high content, which greatly simplifies the subsequent separation and purification process.

[0020] Green and environmentally friendly: The heterogeneous catalytic system is adopted, and the catalyst can be reused by simple filtration or direct regeneration after the reaction. The process does not produce alkaline wastewater, which greatly reduces the environmental burden.

[0021] The catalyst is highly efficient and stable: the prepared solid base catalyst has abundant basic sites and surface hydroxyl groups, exhibiting high catalytic activity and long lifespan.

[0022] High application value of the product: The obtained single isomer, as a raw material for polymers such as polyurethane, can provide highly consistent reactivity and polymerization kinetics, thereby achieving precise control of polymer molecular structure, endowing the final product with more superior and stable mechanical properties, thermal properties and hydrolytic stability, and meeting the application needs of high-end fields. Attached Figure Description

[0023] Figure 1 This is the gas chromatogram (GC chromatogram) of the product obtained in Example 1.

[0024] Figure 2 The GCMS spectrum of the product obtained in Example 1 is shown. According to the comparison with the NIST spectral library and the standard, the product is 1,1'-oxadiyl-2-propanol.

[0025] Figure 3 The image shows the GC chromatogram of commercially available dipropylene glycol, in which the content of 1,1'-oxadiyl-2-propanol is 31.0851%.

[0026] Figure 4 The process flow diagram for the co-production of 1'-oxadiyl-2-propanol and tripropylene glycol as described in this application is shown. Detailed Implementation

[0027] The present invention will be further described in detail below through specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0028] Example 1: Preparation of 1,1'-oxadiyl-2-propanol and tripropanediol by batch reaction in a reaction vessel Preparation of solid base catalysts Dissolve 5 g of calcium oxide in 180 g of deionized water and stir until homogeneous at 60 °C. Add 5 g of calcium nitrate to the above solution and stir until homogeneous. Add 70 g of alumina carrier to the above liquid and stir for 1 h. Then age at 80 °C for 8 h. After aging, filter and dry the filter cake at 120 °C to constant weight.

[0029] Grind to 30 mesh and calcine in a muffle furnace at 600℃ for 4 h to obtain a solid base catalyst.

[0030] reaction process 729.6 g of propylene glycol was added to a reactor, and 348 g of propylene oxide was simultaneously introduced to carry out the reaction. The molar ratio of propylene glycol to propylene oxide was 1.6:1. The catalyst mass was 50 g, which was 4.64% of the total mass of the raw materials. The reaction temperature was controlled at 140℃ and the pressure was 0.6 MPa. The reaction was stopped after 5 h.

[0031] Separation and purification After reaction, the product was separated and purified to obtain 632 g of 1,1'-oxadiyl-2-propanol and 220 g of tripropylene glycol, respectively. The content of 1,1'-oxadiyl-2-propanol was determined to be 99.14% by gas chromatography normalization (see Appendix). Figure 1 The GCMS results for product 1,1'-oxadiyl-2-propanol, compared with the NIST spectral library and standards, are shown in the appendix. Figure 2 .

[0032] Unreacted propylene glycol is recycled via reflux.

[0033] Example 2: Preparation of 1,1'-oxadiyl-2-propanol and tripropanediol by fixed-bed continuous reaction Preparation of solid base catalysts 215 g of potassium oxide was dissolved in 3000 g of deionized water and stirred at 50 °C for 30 min. 71 g of potassium chloride was added to the above solution and stirred for 30 min. 1140 g of silica carrier was added to the above liquid and stirred for 1.5 h. Subsequently, the mixture was aged at 70 °C for 12 h. After aging, the mixture was filtered, and the filter cake was dried at 130 °C to constant weight.

[0034] The mixture was ground to 40 mesh and calcined in a muffle furnace at 700°C for 5 h to obtain a solid base catalyst. 1420 g (approximately 1.78 L) of the prepared solid base catalyst was packed into a fixed-bed reactor.

[0035] reaction process Propylene glycol and propylene oxide were continuously fed into a fixed-bed reactor at a molar ratio of 2.2:1. The mass flow rate of propylene glycol was 1005 g / h, and the mass flow rate of propylene oxide was 348 g / h. The liquid hourly space velocity (LHSV) was 0.8 h⁻¹. The reaction temperature was controlled at 150 °C, and the pressure was 0.8 MPa.

[0036] Separation and purification After reacting for 3 hours, the product was separated and purified to obtain 2100 g of 1,1'-oxadiyl-2-propanol and 400 g of tripropylene glycol. The 1,1'-oxadiyl-2-propanol was found to be 99.21% by gas chromatography normalization. The unreacted propylene glycol was recycled by reflux.

[0037] Example 3: Preparation of 1,1'-oxadiyl-2-propanol and tripropanediol by fixed-bed continuous reaction Preparation of solid base catalysts 200 g of magnesium oxide was dissolved in 3000 g of deionized water and stirred at 50 °C for 30 min. 80 g of potassium nitrate was added to the above solution and stirred for 30 min. 1140 g of magnesium oxide carrier was added to the above liquid and stirred for 1 h. Then, the mixture was aged at 60 °C for 10 h. After aging, the mixture was filtered and the filter cake was dried at 150 °C to constant weight.

[0038] Grind to 40 mesh and calcine in a muffle furnace at 700℃ for 4 h to obtain a solid base catalyst. Take 1420 g (approximately 1.78 L) of the solid base catalyst prepared above and pack it into a fixed-bed reactor.

[0039] reaction process Propylene glycol and propylene oxide were continuously fed into a fixed-bed reactor at a molar ratio of 3:1. The mass flow rate of propylene glycol was 1000 g / h, and the mass flow rate of propylene oxide was 255 g / h. The liquid hourly space velocity (LHSV) was 0.58 h⁻¹. The reaction temperature was controlled at 140 °C, and the pressure was 0.6 MPa.

[0040] Separation and purification After reacting for 2 hours, the product was separated and purified to obtain 520 g of 1,1'-oxadiyl-2-propanol and 75 g of tripropylene glycol. The 1,1'-oxadiyl-2-propanol was found to be 99.23% by gas chromatography normalization. The unreacted propylene glycol was recycled by reflux.

[0041] Example 4: Batch reaction in a reactor to prepare 1,1'-oxadiyl-2-propanol and tripropanediol Preparation of solid base catalysts Dissolve 8 g of cesium oxide in 300 g of deionized water and stir until homogeneous at 60 °C. Add 10 g of magnesium carbonate to the above solution and stir until homogeneous. Add 80 g of alumina carrier to the above liquid and stir for 2 h. Then age at 80 °C for 12 h. After aging, filter and dry the filter cake at 130 °C to constant weight.

[0042] Grind to 30 mesh and calcine in a muffle furnace at 600℃ for 4 h to obtain a solid base catalyst.

[0043] reaction process 592 g of propylene glycol was added to a reaction vessel, and 348 g of propylene oxide was simultaneously introduced to carry out the reaction. The molar ratio of propylene glycol to propylene oxide was 1.3:1. The catalyst mass was 36 g, which was 3.83% of the total mass of the reactants. The reaction temperature was controlled at 140℃ and the pressure was 0.6 MPa. The reaction was stopped after 5 h.

[0044] Separation and purification After the reaction, the product was separated and purified to obtain 500 g of 1,1'-oxadiyl-2-propanol and 395 g of tripropylene glycol, respectively. The content of 1,1'-oxadiyl-2-propanol was 99.03% as determined by gas chromatography normalization.

[0045] Unreacted propylene glycol is recycled via reflux.

[0046] Example 5: Preparation of 1,1'-oxadiyl-2-propanol and tripropanediol by batch reaction in a reactor (using regenerated catalyst) Regeneration of solid base catalysts The deactivated solid base catalyst from Example 1 was regenerated by calcining it in air at 700°C for 3 hours.

[0047] reaction process 912 g of propylene glycol was added to the reactor, and 348 g of propylene oxide was introduced simultaneously for reaction. The molar ratio of the two was 2.0:1. The mass of the regenerated catalyst was 75 g, which was 5.95% of the total mass of the raw materials. The reaction temperature was controlled at 130 ℃ and the pressure at 0.5 MPa. The reaction was stopped after 6 h.

[0048] Separation and purification After the reaction, the product was separated and purified to obtain 665 g of 1,1'-oxadiyl-2-propanol and 161 g of tripropylene glycol. The content of 1,1'-oxadiyl-2-propanol was 99.02% as determined by gas chromatography normalization. The unreacted propylene glycol was recycled by reflux. Analysis and testing methods:

[0049] GC conditions: Agilent 7890B gas chromatograph, INNO-WAX column (30 m × 0.32 mm × 0.25 μm). Injector temperature 260℃, detector (FID) temperature 280℃. Column temperature program: initial 60℃, hold for 5 min, increase to 230℃ at 10℃ / min, hold for 10 min.

[0050] GCMS conditions: Bruker Scion SQ 456 gas chromatograph-mass spectrometer, INNO-WAX column (30 m × 0.32 mm × 0.25 μm). Injector temperature 260 °C, detector (FID) temperature 280 °C. Column temperature program: initial 60 °C, hold for 5 min, ramp at 10 °C / min to 230 °C, hold for 10 min. Transfer line temperature 250 °C, EI source temperature 230 °C.

Claims

1. A method for the co-production of 1,1'-oxadiyl-2-propanol and tripropanediol, characterized in that, Using propylene oxide and propylene glycol as raw materials, a catalytic reaction was carried out in the presence of a solid base catalyst. After the reaction, 1,1'-oxadiyl-2-propanol and tripropylene glycol were obtained by separation and purification.

2. The method according to claim 1, characterized in that, The molar ratio of propylene glycol to propylene oxide is 1.2:1 to 5:1, preferably 1.5:1 to 2.5:

1.

3. The method according to claim 1, characterized in that, The reaction temperature range is 80-200℃, preferably 120-160℃, and the pressure is 0.3-1.0 MPa.

4. The method according to claim 1, characterized in that, The reaction method is either a batch reaction in a reactor or a continuous reaction in a fixed bed.

5. The method according to claim 4, characterized in that, When the reaction method employs a batch reaction in a reactor, the mass of the solid base catalyst is 1% to 10% of the total mass of the raw materials.

6. The method according to claim 4, characterized in that, When the reaction method employs a fixed-bed continuous reaction, the raw materials are continuously fed for the reaction, and the liquid hourly space velocity is 0.1-2.0 h⁻¹.

7. The method according to claim 1, characterized in that, The solid base catalyst is composed of basic oxides and metal salts, forming a dual active center.

8. The method according to claim 7, characterized in that, The preparation method of the solid base catalyst is as follows: 1) Dissolve 5-20 parts by weight of the basic oxide in 50-200 parts by weight of deionized water and stir at 40 ℃~60 ℃ for 10-30 minutes; 2) Add 1-10 parts by weight of metal salt to the solution obtained in step 1) and continue stirring for 20-60 min; 3) Add 70-90 parts by weight of carrier to the mixture obtained in step 2) and stir at the same temperature for 1-4 hours; 4) Aging the slurry obtained in step 3) at 20℃~80℃ for 2~12 h; 5) After aging, filter the filter cake and dry it at 110℃~150℃ to constant weight. 6) Grind the dried solid to 10-60 mesh and calcine it at 400℃-800℃ for 2-6 h to obtain the solid base catalyst.

9. The method according to claim 7, characterized in that, The solid base catalyst support is a metal oxide, selected from alumina, magnesium oxide, silicon dioxide or activated carbon.

10. The method according to claim 1, characterized in that, The deactivated solid base catalyst is regenerated by calcining in air at 500-1000℃ for 2-4 hours and then reused.

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