A process for the continuous production of fatty alcohols from natural oils

Abstract

The application discloses a kind of natural oil continuous preparation of fatty alcohol process, it is related to chemical engineering field.The soft phospholipid in soybean oil is removed by pretreatment, and the service life of catalyst is improved by optimizing hydrogenation reaction condition to improve reaction stability.The specific steps include: first, soybean oil is reacted with methanol under high temperature and high pressure to generate fatty acid methyl ester;Then, the fatty acid methyl ester is subjected to hydrogenation reaction to obtain fatty alcohol and methanol;Finally, the fatty alcohol products with different carbon chain lengths are separated by fractional distillation.The application provides the feasibility of producing fatty alcohol using soybean oil as raw material, and the production process is stable, the product purity is high, the service life of catalyst is long, and has significant industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and in particular to a process for the continuous preparation of fatty alcohols from natural oils. Background Technology

[0002] Fatty alcohols are high-carbon alcohol compounds containing 8-22 carbon atoms. They are important raw materials for surfactants, lubricants, cosmetics, detergents, and various fine chemical products. Industrially, fatty alcohols are mainly derived from two sources: natural sources and petrochemical synthesis. Natural fatty alcohols, prepared from vegetable oils, have the advantages of being green and sustainable, and dominate the daily chemical and detergent markets. Naturally derived fatty alcohols are typically prepared by transesterification of oils followed by hydrogenation; this route has become one of the mainstream methods for current industrial production.

[0003] Currently, the raw materials for large-scale industrial production of natural fatty alcohols are mainly oils with high saturated fatty acid content, such as palm oil, palm kernel oil, and coconut oil. These raw materials have the following advantages: Firstly, they contain a high proportion of medium-chain alcohols, which can meet the strong demand for C12-14 fatty alcohols in downstream detergents and daily chemical markets; secondly, the unsaturated fatty acid content in these oil systems is relatively low, making the hydrogenation reaction process more temperature-controlled, the catalyst more stable, and reducing problems such as catalyst poisoning and deactivation caused by side reactions. The aforementioned technology can also be seen in relevant patent literature as the mainstream technical route for the industrial preparation of fatty alcohols via the hydrogenation of fatty acid methyl esters.

[0004] For example, the existing patent US20060205965A1 discloses a method for preparing fatty alcohols by hydrogenation of fatty acid methyl esters. This method also uses methyl esters from palm oil or coconut oil as hydrogenation raw materials and emphasizes obtaining high-purity fatty alcohols and glycerol byproducts through catalytic hydrogenation.

[0005] For example, the US8426654B2 patent published by Lurgi GmbH also describes the preparation of fatty alcohols through the hydrogenation reaction of fatty acids and fatty esters, and optimizes various catalysts and reaction conditions in traditional methods, further illustrating the wide application of saturated oil feedstocks in industrial production.

[0006] The patent EP2522650NWB1 filed in the EU and other regions also mentions obtaining fatty alcohols in fractionation ranges of C6-C10, C12-C14 and C16-C18 by hydrogenating methyl esters, and puts forward specific technical suggestions for subsequent separation and purification. This corresponds to the conventional route of current industrial products being graded and purified according to their intended use.

[0007] Although traditional saturated oilseeds have mature technological experience in the preparation of fatty alcohols, they face significant supply and market limitations. For example, palm oil is mainly produced in countries like Indonesia and Malaysia, creating a dependence on domestic raw material supply. Meanwhile, as domestic demands for stable raw material sources and cost control increase, exploring locally available oil resources has become an important direction for technological development.

[0008] Soybean oil, as a domestically abundant oilseed with mature supply chains in other industries, faces significant technical challenges when used directly in the production of fatty alcohols. Soybean oil contains a high proportion of unsaturated fatty acids and impurities such as lecithin. These components can easily cause thermal instability during the hydrogenation process. Furthermore, the presence of double bonds and heteroatoms in unsaturated fatty acids can trigger side reactions on the surface of the hydrogenation catalyst, leading to catalyst poisoning, deactivation, or reduced selectivity, thus affecting the yield and distribution of fatty alcohols.

[0009] Therefore, although existing technical literature has described the mainstream process routes for the hydrogenation of fatty acid methyl esters to produce fatty alcohols, and generally uses saturated or moderately saturated vegetable oil feedstocks, there is still a lack of specific solutions for highly unsaturated oil feedstocks such as soybean oil. Developing a fatty alcohol production process suitable for soybean oil requires combining pretreatment, optimization of hydrogenation operating conditions, catalyst selection and protection strategies, and feedstock ratio control to overcome process fluctuations and catalyst deactivation problems caused by unsaturated fatty acids, thereby realizing a feasible industrial-scale fatty alcohol production process using soybean oil as feedstock. Summary of the Invention

[0010] Based on the problems raised in the background art mentioned above, this invention proposes a process for the continuous preparation of fatty alcohols from natural oils.

[0011] The technical solution is as follows:

[0012] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0013] a) High-pressure alcoholysis step: Natural oil raw materials and methanol are added to a high-pressure alcoholysis reactor according to the following mass fractions: 100 parts by mass of natural oil raw materials and 150-300 parts by mass of methanol. The alcoholysis reaction is carried out under set conditions to produce fatty acid methyl esters and glycerol. The reactor liquid level is maintained at 50-60%.

[0014] b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) is mixed with methanol in a mixer at a mass ratio of 100:(20–80), and the mixture is pressurized to 24.5–25.5 MPa by a high-pressure feed pump;

[0015] c) High-pressure hydrogenation step: After mixing the mixture from step b) with hydrogen in a mass ratio of 100:(50–200), add 2-5 parts of supported palladium resin catalyst under set conditions, and carry out hydrogenation reaction through a fixed-bed catalytic hydrogenation reactor to produce fatty alcohols and methanol.

[0016] d) Gas-liquid separation step: After cooling the hydrogenation product in step c) to 35–70°C, high-pressure separation is performed to recover and reuse the circulating hydrogen. The liquid level in the high-pressure separator is controlled at 20–50%.

[0017] e) Depressurization and medium-pressure separation step: The liquid phase is flash-evaporated to 2.0 MPa under reduced pressure, and dissolved hydrogen and methanol are separated in a medium-pressure separator at 1.0–2.5 MPa;

[0018] f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is separated by atmospheric distillation to obtain a series of natural fatty alcohol products classified according to carbon chain length.

[0019] As a preferred embodiment of the present invention, the natural oil raw material in the high-pressure alcoholysis step is at least one of coconut oil, palm kernel oil, palm oil, soybean oil, or a mixture thereof.

[0020] As a preferred embodiment of the present invention, the high-pressure alcoholysis step is performed at a reaction temperature of 230–240°C and a pressure of 8.4–8.6 MPa.

[0021] As a preferred embodiment of the present invention, the molar ratio of methanol to fatty acid methyl ester at the reactor outlet in the high-pressure alcoholysis step is 1:(0.8–1.2).

[0022] As a preferred embodiment of the present invention, the high-pressure alcoholysis reactor is provided with three continuous reaction zones in series, with outlet temperatures of 230–240℃, 230–240℃, and 230–240℃ for each stage.

[0023] As a preferred embodiment of the present invention, the high-pressure hydrogenation step has a reaction temperature of 180–225°C and a pressure of 24.5–25.5 MPa.

[0024] As a preferred embodiment of the present invention, the preparation method of the supported palladium resin catalyst is as follows:

[0025] S1: Add 100-120 parts of type 732 resin to the reactor, soak it in 1220-1570 parts of toluene for 1.5-2.5 hours, filter it, and dry it to constant weight; purge with nitrogen to remove oxygen for 10-30 minutes, raise the temperature to 60-70℃, add 10-18 parts of diethyl 2-allyl phosphite and 0.8-1.3 parts of p-toluenesulfonic acid, and react for 2-5 hours to complete the phosphorylation modification; maintain the temperature at 60-75℃;

[0026] S2: Add 2-5 parts of 4,6-dihydroxy-2-mercaptopyrimidine and 0.5-1.0 parts of azobisisobutyronitrile, and stir for 1.5-2.5 hours to complete the mercapto-olefin addition reaction; cool to 30-40℃, add palladium nitrate, and stir for coordination reaction for 3-5 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and wash 3-5 times with toluene and 2-4 times with ethanol, and vacuum dry at 85-95℃ for 7-9 hours. Sieve to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0027] As a preferred embodiment of the present invention, the gas phase separated under high pressure in the gas-liquid separation step is compressed and sent back to the hydrogenation mixing section by a circulating gas compressor, and the recovered methanol and hydrogen are used in steps b) and c).

[0028] As a preferred embodiment of the present invention, the liquid level in the medium-pressure separator is controlled at 20–40% during the pressure reduction and medium-pressure separation step.

[0029] As a preferred technical solution of the present invention, the method prepares a series of natural fatty alcohol products classified by carbon chain length as follows: C6, C8–10, C12, C12–14, C14, C16, C16–18, and C18.

[0030] Reaction mechanism of supported palladium resin catalyst:

[0031] After toluene pretreatment, the crosslinked network of the 732 resin swells and surface impurities are washed away, exposing active reaction sites. Following nitrogen deoxygenation, under elevated temperature, diethyl 2-allyl phosphite undergoes phosphorylation with the active groups on the resin surface, grafting phosphoryl functional groups containing allyl groups (olefin structures) onto the resin surface. Maintaining a constant reaction temperature, the thiol group in 4,6-dihydroxy-2-mercaptopyrimidine undergoes a mercapto-olefin addition reaction with the allyl group on the phosphoryl group, initiated by azobisisobutyronitrile, forming a stable carbon-sulfur covalent bond and introducing sulfur-based functional groups containing hydroxyl and pyrimidine rings onto the resin surface. After cooling, palladium nitrate is added. Palladium ions form a double stable coordination bond with the oxygen atom in the phosphoryl group and the lone pair electrons of the sulfur atom introduced after addition through empty orbitals, constructing a highly efficient catalytic active center. Simultaneously, the original sulfonic acid group structure of the resin is preserved, synergistically optimizing the catalytic environment of the reaction system and ensuring the directed and efficient conduction of the hydrogenation reaction.

[0032] Effects of supported palladium resin catalyst technology:

[0033] Improving the selectivity of hydrogenation reactions can precisely activate the ester groups in fatty acid methyl esters, promote their directional reduction to fatty alcohols, inhibit excessive hydrogenation of unsaturated fatty acids and other side reactions, and optimize the distribution of target products.

[0034] To enhance the structural stability of the catalyst, the active palladium component is firmly fixed through the dual coordination of phosphoryl groups and sulfide functional groups, preventing its aggregation or loss and extending the continuous operation cycle of the catalyst.

[0035] To enhance resistance to impurity poisoning, the pyrimidine rings and hydroxyl groups grafted onto the resin surface can reduce the adsorption and damage of polar impurities such as lecithin in soybean oil to the catalytic active sites, ensuring the continuous and stable progress of the hydrogenation reaction.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. By systematically optimizing the pretreatment and hydrogenation process of soybean oil raw materials, the negative impact of unsaturated fatty acids and lecithin impurities on the stability of the hydrogenation reaction in the existing technology is effectively mitigated. This not only improves the controllability of the hydrogenation reaction and the durability of the catalyst, but also improves product selectivity and refining efficiency.

[0038] 2. This invention overcomes the temperature fluctuations and catalyst poisoning problems that easily occur in the context of high unsaturated fatty acids, making the hydrogenation reaction section more stable and thus improving the overall continuity and repeatability of the reaction. The pretreatment step effectively reduces potential catalyst toxicity impurities such as phospholipids in soybean oil, enabling the catalyst to maintain high activity and selectivity over a longer period, thereby improving equipment operating efficiency and catalyst utilization.

[0039] 3. By optimizing the process design of methyl ester conversion and hydrogen circulation, this invention can reduce the generation of side reactions, improve the selectivity of fatty acid methyl ester conversion to fatty alcohols, and reduce the content of byproducts that may be generated under the influence of unsaturated fatty acids. This not only helps to reduce the difficulty of subsequent separation and processing, but also improves the purity and quality consistency of the final fatty alcohol product, which is conducive to meeting the performance requirements of daily chemical and downstream high value-added markets. Detailed Implementation

[0040] The present invention will be further described below with reference to the embodiments. The embodiments described below are illustrative and not limiting, and should not be used to limit the scope of protection of the present invention.

[0041] Example 1

[0042] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0043] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass fractions: 100 kg of natural oil raw material (coconut oil) and 150 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 230℃ and the reaction pressure at 8.4 MPa, and the reactor liquid level controlled at 50%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:0.8, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0044] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:20. The stirring device of the mixer is turned on (speed 300 r / min) and mixed for 15 minutes until the material is uniform. The mixture is pressurized to 24.5 MPa by a high-pressure feed pump and then stably transported to the hydrogenation mixing section.

[0045] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into the hydrogenation mixer at a mass ratio of 100:50. After thorough mixing, it is introduced into the fixed-bed catalytic hydrogenation reactor. 2 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 180℃, the reaction pressure to 24.5 MPa, and the material space velocity is controlled to 0.5 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0046] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 35°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 20% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 24.5 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol, and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0047] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 1.0 MPa and the liquid level at 20%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0048] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 80°C, the column bottom temperature to 280°C, and the reflux ratio to 3:1. Through continuous distillation separation, a series of natural fatty alcohol products such as C8, C10, and C12 are obtained in sequence according to the carbon chain length, with a product purity ≥99.0%.

[0049] The preparation method of the supported palladium resin catalyst is as follows:

[0050] 1. S1: Add 100 kg of 732 type resin to a 5000 L reactor, add 1220 kg of toluene and soak for 1.5 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 80℃ to constant weight; put the dried resin back into the reactor, purge with nitrogen (flow rate 100 mL / min) to remove oxygen for 10 minutes, raise the temperature to 60℃, add 10 kg of 2-allyl diethyl phosphite (CAS: 682-34-8) and 0.8 kg of p-toluenesulfonic acid, stir at 200 r / min, and react for 2 hours to complete the phosphorylation modification; maintain the reactor temperature at 60℃.

[0051] 2. S2: Add 2 kg of 4,6-dihydroxy-2-mercaptopyrimidine and 0.5 kg of azobisisobutyronitrile to the reactor, stir at 250 r / min, and react for 1.5 hours to complete the mercapto-olefin addition reaction; cool to 30℃, slowly add palladium nitrate solution (containing 0.5 kg of palladium), stir at 200 r / min, and coordinate reaction for 3 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and collect the resin, wash 3 times with toluene (500 kg each time), and wash 2 times with ethanol (300 kg each time); place the washed resin in a vacuum drying oven, dry at 85℃ for 7 hours, and sieve through a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0052] Example 2

[0053] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0054] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass fractions: 100 kg of natural oil raw material (palm kernel oil) and 200 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 233℃, the reaction pressure at 8.5 MPa, and the reactor liquid level controlled at 53%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:0.9, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0055] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:40. The stirring device of the mixer is turned on (speed 350 r / min) and mixed for 12 minutes until the material is uniform. The mixture is pressurized to 25.0 MPa by a high-pressure feed pump and then stably transported to the hydrogenation mixing section.

[0056] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into the hydrogenation mixer at a mass ratio of 100:100. After thorough mixing, it is introduced into the fixed-bed catalytic hydrogenation reactor. 3 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 200℃, the reaction pressure to 25.0 MPa, and the material space velocity is controlled to 0.7 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0057] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 45°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 30% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 25.0 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0058] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 1.5 MPa and the liquid level at 28%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0059] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 85℃, the column bottom temperature to 290℃, and the reflux ratio to 4:1. Through continuous distillation separation, a series of natural fatty alcohol products, namely C8, C10, C12, and C14, are obtained in sequence according to the carbon chain length. The purity of the products is ≥99.2%.

[0060] The preparation method of the supported palladium resin catalyst is as follows:

[0061] 1. S1: Add 105 kg of 732 type resin to a 5000 L reactor, add 1320 kg of toluene and soak for 2.0 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 82℃ to constant weight; put the dried resin back into the reactor, purge with nitrogen (flow rate 120 mL / min) to remove oxygen for 20 minutes, raise the temperature to 65℃, add 13 kg of 2-allyl diethyl phosphite (CAS: 682-34-8) and 1.0 kg of p-toluenesulfonic acid, stir at 220 r / min, and react for 3 hours to complete the phosphorylation modification; maintain the reactor temperature at 68℃.

[0062] 2. S2: Add 3 kg of 4,6-dihydroxy-2-mercaptopyrimidine and 0.7 kg of azobisisobutyronitrile to the reactor, stir at 260 r / min, and react for 2.0 hours to complete the mercapto-olefin addition reaction; cool to 35℃, slowly add palladium nitrate solution (containing 0.7 kg of palladium), stir at 220 r / min, and coordinate reaction for 4 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and collect the resin, wash 4 times with toluene (500 kg each time) and 3 times with ethanol (300 kg each time); put the washed resin into a vacuum drying oven and dry at 90℃ for 8 hours, then sieve with a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0063] Example 3

[0064] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0065] 1. a) High-pressure alcoholysis step: The raw materials are accurately weighed according to the mass fractions: 100 kg of natural oil raw material (palm oil) and 250 kg of methanol. The two are continuously fed into the high-pressure alcoholysis reactor through a metering pump. The reactor is equipped with three-stage continuous series reaction zones. The reaction temperature of each stage is set at 237°C, the reaction pressure is 8.5 MPa, and the reactor liquid level is controlled to be maintained at 57%. The material ratio is monitored in real time during the reaction to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:1.1, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0066] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:60. The stirring device of the mixer is turned on (speed 400 r / min) and mixed for 10 minutes until the material is uniform. The mixture is pressurized to 25.3 MPa by a high-pressure feed pump and then stably conveyed to the hydrogenation mixing section.

[0067] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into the hydrogenation mixer at a mass ratio of 100:150. After thorough mixing, it is introduced into a fixed-bed catalytic hydrogenation reactor. 4 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 215℃, the reaction pressure to 25.3 MPa, and the material space velocity is controlled to 0.9 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0068] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 60°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 40% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 25.3 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0069] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 2.0 MPa and the liquid level at 35%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0070] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 90℃, the column bottom temperature to 300℃, and the reflux ratio to 5:1. Through continuous distillation separation, a series of natural fatty alcohol products, namely C12, C14, C16, and C18, are obtained in sequence according to the carbon chain length. The product purity is ≥99.3%.

[0071] The preparation method of the supported palladium resin catalyst is as follows:

[0072] 1. S1: Add 115 kg of 732 type resin to a 5000 L reactor, add 1470 kg of toluene and soak for 2.3 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 85 °C to constant weight; put the dried resin back into the reactor, purge with argon gas (flow rate 140 mL / min) to remove oxygen for 25 minutes, raise the temperature to 68 °C, add 16 kg of 2-allyl diethyl phosphite (CAS: 682-34-8) and 1.2 kg of p-toluenesulfonic acid, stir at 240 r / min, and react for 4 hours to complete the phosphorylation modification; maintain the reactor temperature at 72 °C.

[0073] 2. S2: Add 4 kg of 4,6-dihydroxy-2-mercaptopyrimidine and 0.9 kg of azobisisobutyronitrile to the reactor, stir at 280 r / min, and react for 2.3 hours to complete the mercapto-olefin addition reaction; cool to 38℃, slowly add palladium nitrate solution (containing 0.9 kg of palladium), stir at 240 r / min, and coordinate reaction for 4.5 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, collect the resin by filtration, wash 4 times with toluene (500 kg each time), and wash 3 times with ethanol (300 kg each time); place the washed resin in a vacuum drying oven, dry at 92℃ for 8.5 hours, and sieve through a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0074] Example 4

[0075] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0076] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass proportions: 100 kg of natural oil raw materials (soybean oil: palm kernel oil: palm oil = 1:1:1 mixture) and 300 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 240℃, the reaction pressure at 8.6 MPa, and the reactor liquid level controlled at 60%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:1.2, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0077] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:80. The stirring device of the mixer is turned on (speed 450 r / min) and mixed for 8 minutes until the material is uniform. The mixture is pressurized to 25.5 MPa by a high-pressure feed pump and then stably conveyed to the hydrogenation mixing section.

[0078] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into a hydrogenation mixer at a mass ratio of 100:200. After thorough mixing, it is introduced into a fixed-bed catalytic hydrogenation reactor. 5 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 225℃, the reaction pressure to 25.5 MPa, and the material space velocity is controlled to 1.0 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0079] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 70°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 50% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 25.5 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0080] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 2.5 MPa and the liquid level at 40%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0081] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 95℃, the column bottom temperature to 310℃, and the reflux ratio to 6:1. Through continuous distillation separation, a series of natural fatty alcohol products, namely C8, C10, C12, C14, C16, and C18, are obtained in sequence according to carbon chain length. The purity of the products is ≥99.5%.

[0082] The preparation method of the supported palladium resin catalyst is as follows:

[0083] 1. S1: Add 120 kg of 732 type resin to a 5000 L reactor, add 1570 kg of toluene and soak for 2.5 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 88℃ to constant weight; put the dried resin back into the reactor, purge with argon gas (flow rate 160 mL / min) to remove oxygen for 30 minutes, raise the temperature to 70℃, add 18 kg of 2-allyl diethyl phosphite (CAS: 682-34-8) and 1.3 kg of p-toluenesulfonic acid, stir at 250 r / min, and react for 5 hours to complete the phosphorylation modification; maintain the reactor temperature at 75℃.

[0084] 2. S2: Add 5 kg of 4,6-dihydroxy-2-mercaptopyrimidine and 1.0 kg of azobisisobutyronitrile to the reactor, stir at 300 r / min, and react for 2.5 hours to complete the mercapto-olefin addition reaction; cool to 40℃, slowly add palladium nitrate solution (containing 1.0 kg of palladium), stir at 250 r / min, and coordinate reaction for 5 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and collect the resin, wash 5 times with toluene (500 kg each time) and 4 times with ethanol (300 kg each time); put the washed resin into a vacuum drying oven and dry at 95℃ for 9 hours, then sieve with a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0085] Comparative Example 1

[0086] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0087] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass fractions: 100 kg of natural oil raw material (coconut oil) and 150 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 230℃ and the reaction pressure at 8.4 MPa, and the reactor liquid level controlled at 50%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:0.8, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0088] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:20. The stirring device of the mixer is turned on (speed 300 r / min) and mixed for 15 minutes until the material is uniform. The mixture is pressurized to 24.5 MPa by a high-pressure feed pump and then stably transported to the hydrogenation mixing section.

[0089] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into a hydrogenation mixer at a mass ratio of 100:50. After thorough mixing, it is introduced into a fixed-bed catalytic hydrogenation reactor. 2 kg of commercially available Cu / Al2O3 catalyst is added to the reactor. The reaction temperature is set to 180℃, the reaction pressure to 24.5 MPa, and the material space velocity is controlled to 0.5 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0090] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 35°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 20% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 24.5 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol, and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0091] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 1.0 MPa and the liquid level at 20%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0092] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 80°C, the column bottom temperature to 280°C, and the reflux ratio to 3:1. Through continuous distillation separation, a series of natural fatty alcohol products such as C8, C10, and C12 are obtained in sequence according to the carbon chain length, with a product purity ≥99.0%.

[0093] Comparative Example 2

[0094] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0095] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass fractions: 100 kg of natural oil raw material (coconut oil) and 150 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 230℃ and the reaction pressure at 8.4 MPa, and the reactor liquid level controlled at 50%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:0.8, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0096] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:20. The stirring device of the mixer is turned on (speed 300 r / min) and mixed for 15 minutes until the material is uniform. The mixture is pressurized to 24.5 MPa by a high-pressure feed pump and then stably transported to the hydrogenation mixing section.

[0097] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into the hydrogenation mixer at a mass ratio of 100:50. After thorough mixing, it is introduced into the fixed-bed catalytic hydrogenation reactor. 2 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 180℃, the reaction pressure to 24.5 MPa, and the material space velocity is controlled to 0.5 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0098] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 35°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 20% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 24.5 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol, and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0099] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 1.0 MPa and the liquid level at 20%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0100] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 80°C, the column bottom temperature to 280°C, and the reflux ratio to 3:1. Through continuous distillation separation, a series of natural fatty alcohol products such as C8, C10, and C12 are obtained in sequence according to the carbon chain length, with a product purity ≥99.0%.

[0101] The preparation method of the supported palladium resin catalyst is as follows:

[0102] 1. S1: Add 100 kg of 732 type resin to a 5000 L reactor, add 1220 kg of toluene and soak for 1.5 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 80 °C to constant weight; put the dried resin back into the reactor, purge with nitrogen (flow rate 100 mL / min) to remove oxygen for 10 minutes, raise the temperature to 60 °C, add 0.8 kg of p-toluenesulfonic acid, stir at 200 r / min, and react for 2 hours to complete the phosphorylation modification; maintain the reactor temperature at 60 °C.

[0103] 2. S2: Add 2 kg of 4,6-dihydroxy-2-mercaptopyrimidine and 0.5 kg of azobisisobutyronitrile to the reactor, stir at 250 r / min, and react for 1.5 hours to complete the mercapto-olefin addition reaction; cool to 30℃, slowly add palladium nitrate solution (containing 0.5 kg of palladium), stir at 200 r / min, and coordinate reaction for 3 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and collect the resin, wash 3 times with toluene (500 kg each time), and wash 2 times with ethanol (300 kg each time); place the washed resin in a vacuum drying oven, dry at 85℃ for 7 hours, and sieve through a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0104] Comparative Example 3

[0105] A process for the continuous preparation of fatty alcohols from natural oils includes the following steps:

[0106] 1. a) High-pressure alcoholysis step: Accurately weigh the raw materials according to the mass fractions: 100 kg of natural oil raw material (coconut oil) and 150 kg of methanol, and continuously feed them into the high-pressure alcoholysis reactor through a metering pump; the reactor is equipped with three-stage continuous series reaction zones, with the reaction temperature of each stage set at 230℃ and the reaction pressure at 8.4 MPa, and the reactor liquid level controlled at 50%; during the reaction, the material ratio is monitored in real time to ensure that the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:0.8, and the alcoholysis reaction is continuously carried out to produce fatty acid methyl ester and glycerol.

[0107] 2. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) and methanol are fed into a static mixer at a mass ratio of 100:20. The stirring device of the mixer is turned on (speed 300 r / min) and mixed for 15 minutes until the material is uniform. The mixture is pressurized to 24.5 MPa by a high-pressure feed pump and then stably transported to the hydrogenation mixing section.

[0108] 3. c) High-pressure hydrogenation step: The mixture after pressurization in step b) is fed into the hydrogenation mixer at a mass ratio of 100:50. After thorough mixing, it is introduced into the fixed-bed catalytic hydrogenation reactor. 2 kg of supported palladium resin catalyst is added to the reactor. The reaction temperature is set to 180℃, the reaction pressure to 24.5 MPa, and the material space velocity is controlled to 0.5 h⁻¹. The catalytic hydrogenation reaction is carried out continuously to produce fatty alcohols and methanol.

[0109] 4. d) Gas-liquid separation step: The hydrogenation product from step c) is passed into a cooler and cooled to 35°C before being sent to a high-pressure separator. The liquid level in the high-pressure separator is controlled at 20% for high-pressure gas-liquid separation. The gas phase is mainly hydrogen, which is compressed to 24.5 MPa by a recirculating gas compressor and then sent back to the hydrogenation mixing section. The separated liquid phase (containing fatty alcohols, methanol, and trace amounts of hydrogen) is sent to subsequent processing steps, and the recovered hydrogen is recycled for use in step c).

[0110] 5. e) Pressure reduction and medium-pressure separation steps: The liquid phase from step d) is sent to a pressure reduction flash tank and flashed to a pressure of 2.0 MPa. During the flashing process, some light components are removed. Then, the material is sent to a medium-pressure separator, and the separator pressure is controlled at 1.0 MPa and the liquid level at 20%. The dissolved hydrogen and methanol are separated. The separated methanol is purified by distillation and then recycled for use in steps a) and b). The hydrogen is recovered to the hydrogenation system.

[0111] 6. f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is fed into an atmospheric distillation column. The column top temperature is set to 80°C, the column bottom temperature to 280°C, and the reflux ratio to 3:1. Through continuous distillation separation, a series of natural fatty alcohol products such as C8, C10, and C12 are obtained in sequence according to the carbon chain length, with a product purity ≥99.0%.

[0112] The preparation method of the supported palladium resin catalyst is as follows:

[0113] 1. S1: Add 100 kg of 732 type resin to a 5000 L reactor, add 1220 kg of toluene and soak for 1.5 hours, stirring for 10 minutes every 20 minutes during the soaking process; after soaking, filter the resin and place it in a vacuum drying oven to dry at 80℃ to constant weight; put the dried resin back into the reactor, purge with nitrogen (flow rate 100 mL / min) to remove oxygen for 10 minutes, raise the temperature to 60℃, add 10 kg of 2-allyl diethyl phosphite (CAS: 682-34-8) and 0.8 kg of p-toluenesulfonic acid, stir at 200 r / min, and react for 2 hours to complete the phosphorylation modification; maintain the reactor temperature at 60℃.

[0114] 2. S2: Add 0.5 kg of azobisisobutyronitrile to the reactor, stir at 250 r / min, and react for 1.5 hours to complete the mercapto-olefin addition reaction; cool to 30℃, slowly add palladium nitrate solution (containing 0.5 kg of palladium), stir at 200 r / min, and coordinate reaction for 3 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction, filter and collect the resin, wash 3 times with toluene (500 kg each time), and wash 2 times with ethanol (300 kg each time); place the washed resin in a vacuum drying oven and dry at 85℃ for 7 hours, then sieve using a vibrating screen to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

[0115] Test method:

[0116] 1. Detection of conversion between raw materials and intermediates

[0117] (a) Determination of fatty acid methyl ester conversion rate (GC-MS)

[0118] Procedure: Dilute the sample in n-hexane (volume ratio adapted to GC requirements). Add internal standard (C17 methyl ester standard) for internal standard quantification. Analyze the carbon chain composition and concentration of fatty acid methyl esters using GC-MS. Set the temperature program, carrier gas (helium), injection mode, and other conditions according to the standard GC operating procedure.

[0119] Calculate the conversion rate of fatty acid methyl esters:

[0120] Conversion rate = (Total fatty acid methyl esters before reaction - Total fatty acid methyl esters after reaction) / Total fatty acid methyl esters before reaction * 100%

[0121] 2. Quantitative analysis of fatty alcohols (HPLC-RID)

[0122] The fatty alcohol sample obtained from distillation was dissolved in a suitable mobile phase (acetonitrile / water or methanol / water) to prepare the analytical sample. A C18 column was used with a flow rate of approximately 1 mL / min and a refractive index detector (RID). The peaks of each carbon chain fatty alcohol were qualitatively and quantitatively analyzed using a reference standard fatty alcohol.

[0123] Purity calculation method:

[0124] fatty alcohol purity = (sum of peak areas of each component of the fatty alcohol) / (total peak area of ​​the sample) * 100%

[0125] 3. Catalyst activity and stability testing

[0126] During the sixth month of continuous operation, samples were taken from the inlet and outlet fluids of the hydrogenation reactor for analysis. The decrease in FAME conversion rate was calculated.

[0127] Test results:

[0128] Table 1 Test Results

[0129] Fatty acid methyl ester conversion rate % fatty alcohol purity % % of catalytic activity decline in the sixth month Example 1 95.6 98.8 5.1 Example 2 95.8 99.1 4.9 Example 3 96.1 99.2 4.8 Example 4 96.2 99.4 4.6 Comparative Example 1 94.4 98.1 / Comparative Example 2 94.8 98.4 7.2 Comparative Example 3 95.0 98.5 6.8

[0130] The test data from the continuous production of fatty alcohols from natural oils show that the modified palladium-supported resin catalyst system exhibits significant advantages. Diethyl 2-allyl phosphite, as the core modifier, provides a dedicated coordination site for palladium ions through phosphorylation, constructing a stable catalytic active center. Furthermore, the allyl group in its molecular structure provides a key olefin active site for the thiol-olefin addition reaction, establishing the foundation for synergistic functional group effects. 4,6-Dihydroxy-2-mercaptopyrimidine, through the addition reaction between the thiol and allyl groups, not only introduces sulfur atoms to assist palladium ions in forming a more stable coordination structure, but its pyrimidine ring and hydroxyl group also specifically resist interference from impurities such as lecithin, reducing the risk of catalyst poisoning. Under the synergistic effect of these two components, the catalyst maintains high catalytic activity during continuous operation, resulting in higher conversion rates of fatty acid methyl esters and higher purity of fatty alcohols than the comparative example. Moreover, the rate of catalytic activity decline in the sixth month is significantly lower than that of the comparative example. This effectively solves the core problems of insufficient catalyst stability and easy poisoning in the hydrogenation process of highly unsaturated oils such as soybean oil, fully meeting the needs of industrial continuous production.

[0131] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. These changes involve related technologies well known to those skilled in the art, and all of them fall within the protection scope of the present invention.

[0132] Many other changes and modifications can be made without departing from the concept and scope of this invention.

[0133] It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A process for the continuous preparation of fatty alcohols from natural oils, characterized in that, Includes the following steps: a) High-pressure alcoholysis step: Natural oil raw materials and methanol are added to a high-pressure alcoholysis reactor according to the following mass fractions: 100 parts by mass of natural oil raw materials and 150-300 parts by mass of methanol. The alcoholysis reaction is carried out under set conditions to produce fatty acid methyl esters and glycerol. The reactor liquid level is maintained at 50-60%. b) Fatty acid methyl ester / methanol mixing step: The fatty acid methyl ester generated in step a) is mixed with methanol in a mixer at a mass ratio of 100:(20–80), and the mixture is pressurized to 24.5–25.5 MPa by a high-pressure feed pump; c) High-pressure hydrogenation step: After mixing the mixture in step b) with hydrogen in a mass ratio of 100:(50–200), add 2-5 parts of supported palladium resin catalyst under set conditions, and carry out the hydrogenation reaction through a fixed-bed catalytic hydrogenation reactor. The hydrogenation products are fatty alcohols and methanol. d) Gas-liquid separation step: After cooling the hydrogenation product in step c) to 35–70°C, high-pressure separation is performed to recover and reuse the circulating hydrogen. The liquid level in the high-pressure separator is controlled at 20–50%. e) Depressurization and medium-pressure separation steps: The liquid phase is flashed under reduced pressure to 2.0 MPa, and dissolved hydrogen and methanol are separated in a medium-pressure separator at 1.0–2.5 MPa; f) Distillation separation step: The fatty alcohol mixture after methanol removal in step e) is separated by atmospheric distillation to obtain a series of natural fatty alcohol products classified according to carbon chain length; The supported palladium resin catalyst was prepared by reacting 732 type resin, diethyl 2-allyl phosphite, p-toluenesulfonic acid, 4,6-dihydroxy-2-mercaptopyrimidine, azobisisobutyronitrile, and palladium nitrate.

2. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: The natural oil raw material in the high-pressure alcoholysis step is at least one of coconut oil, palm kernel oil, palm oil, soybean oil, or a mixture thereof.

3. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: The high-pressure alcoholysis step is performed at a temperature of 230–240°C and a pressure of 8.4–8.6 MPa.

4. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: In the high-pressure alcoholysis step, the molar ratio of methanol to fatty acid methyl ester at the reactor outlet is 1:(0.8–1.2).

5. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: The high-pressure alcoholysis reactor is equipped with three continuous reaction zones connected in series, with outlet temperatures of 230–240℃, 230–240℃, and 230–240℃ for each stage, respectively.

6. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: The high-pressure hydrogenation step is performed at a reaction temperature of 180–225°C and a pressure of 24.5–25.5 MPa.

7. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: The preparation method of the supported palladium resin catalyst is as follows: S1: Add 100-120 parts of type 732 resin to the reactor, soak in 1220-1570 parts of toluene for 1.5-2.5 hours, filter, and dry to constant weight; purge with nitrogen to remove oxygen for 10-30 minutes, raise the temperature to 60-70℃, add 10-18 parts of 2-allyl phosphite diethyl ester (CAS: 682-34-8) and 0.8-1.3 parts of p-toluenesulfonic acid, react for 2-5 hours to complete phosphorylation modification; maintain the temperature at 60-75℃; S2: Add 2-5 parts of 4,6-dihydroxy-2-mercaptopyrimidine and 0.5-1.0 parts of azobisisobutyronitrile, and stir for 1.5-2.5 hours to complete the mercapto-olefin addition reaction; cool to 30-40℃, add palladium nitrate, and stir for coordination reaction for 3-5 hours to form stable coordination bonds between palladium ions and phosphoryl groups; after the reaction is completed, filter and wash 3-5 times with toluene and 2-4 times with ethanol, and vacuum dry at 85-95℃ for 7-9 hours. Sieve to retain the product with a particle size of 0.315-1.25 mm to obtain the supported palladium resin catalyst.

8. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: In the gas-liquid separation step, the gas phase separated under high pressure is compressed and sent back to the hydrogenation mixing section by a circulating gas compressor, and the recovered methanol and hydrogen are used in steps b) and c).

9. The process for continuous preparation of fatty alcohols from natural oils according to claim 1, characterized in that: During the pressure reduction and medium-pressure separation steps, the liquid level in the medium-pressure separator is controlled at 20–40%.

10. A process for the continuous preparation of fatty alcohols from natural oils according to claims 1-9, characterized in that: The method prepares a series of natural fatty alcohols classified by carbon chain length, namely: C6, C8–10, C12, C12–14, C14, C16, C16–18, and C18.