Method for comprehensively utilizing m-pentadiene

Abstract

The invention provides a comprehensive utilization method of m-pentadiene, and relates to the technical field of resource utilization, and the method comprises the following steps: S1, carrying out selective hydrogenation on m-pentadiene as a raw material under the action of a catalyst to generate n-pentene and 2-pentene; s2, the pentene prepared in the step S1 and synthesis gas are subjected to a carbonyl synthesis reaction under the action of a rhodium catalyst and a carrier to generate n-hexanal and iso-hexanal, the n-hexanal and the iso-hexanal are mixed and then hydrogenated, and n-hexanol and iso-hexanol are prepared; and S3, carrying out carbon-carbon double bond nucleophilic addition on n-hexanal and iso-hexanal prepared in the step S2 under the action of a basic catalyst, then carrying out deprotonation on hydroxyl to generate dodecenal, and finally carrying out hydrogenation on the generated dodecenal to prepare the isododecanol. The invention provides a new method for comprehensively utilizing the m-pentadiene, which not only opens up a new production line for comprehensively utilizing the m-pentadiene, but also utilizes the m-pentadiene as a raw material to produce different new material chemicals with high added values, thereby greatly enhancing the utilization value of the m-pentadiene.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization, and particularly to a method for comprehensive utilization of piperylene. Background Art

[0002] Piperylene is a colorless transparent liquid, insoluble in water, soluble in ethanol, ether, acetone, and benzene; it has strong unsaturated properties; it mainly comes from C5 separation and can also be synthesized through dehydrogenation reactions of olefins and addition reactions of unsaturated hydrocarbons. Piperylene has various uses in the chemical industry. Currently, its main industrial use is to produce petroleum resins, which belong to a type of C5 aliphatic petroleum resins; with the continuous development of piperylene petroleum resin technology, it is widely used in fields such as pressure-sensitive adhesives, light-colored hot-melt adhesives, light-colored hot-melt marking paints, hot-melt coatings, rubber tackifiers, paint and printing ink additives, etc.; at the same time, it can also be used as a catalyst and solvent in organic synthesis.

[0003] Currently, the main methods for the utilization of piperylene in China are as follows:

[0004] Piperylene can undergo addition reactions with a large number of products. The key addition effects among them are the addition effects with maleic anhydride starting from two olefins. The product is 3-methyltetrahydrophthalic anhydride. Continuing to add hydrogen atoms, the product is methylhexahydrophthalic anhydride. They can both be used as epoxy solidifying solvents.

[0005] The aliphatic petroleum resin prepared by the reaction of piperylene in polymerization and copolymerization experiments can also start copolymerization with the remaining molecules; for example, copolymerizing with isoprene to prepare butyl-pentene rubber, which is a very important substance in copolymer rubber; piperylene can also copolymerize with styrene, and the prepared substance is a raw material with good properties.

[0006] Currently, piperylene petroleum resin, that is, C5 aromatic petroleum resin, is the main utilization aspect of piperylene; piperylene petroleum resin is basically used in the following aspects, such as preparing tape adhesives, road markings, paints, and rubber.

[0007] Chinese Patent CN202311189671.2 discloses a method for synthesizing an alternating copolymer by using piperylene monomers as raw materials and styrene through anionic polymerization, and epoxidizing the unsaturated double bonds in the alternating copolymer with m-chloroperbenzoic acid. Controlling the molar ratio of carbon-carbon double bonds in the alternating copolymer to m-chloroperbenzoic acid to be 1:1.25, at a certain temperature, pressure, solvent, and mass concentration, the epoxy degree of the double bonds in the obtained alternating copolymer can reach more than 99%. The formed copolymer can be widely used in fields such as optics and children's toys.

[0008] Chinese Patent CN201610966259.0 discloses a method for preparing modified isoprene hydrogenated petroleum resin using isoprene as a raw material. First, an imidazole compound is used as a modifier, and the modifier is added during the polymerization of isoprene to obtain isoprene-modified petroleum resin. Then, the isoprene-modified petroleum resin is catalytically hydrogenated to obtain modified isoprene hydrogenated petroleum resin.

[0009] Chinese Patent CN202010242582.X provides a method for synthesizing leaf alcohol from isoprene. Isoprene reacts with carbon monoxide and hydrogen to prepare an intermediate, cis-3-hexen-1-al, which is then hydrogenated to obtain leaf alcohol. In the synthesis method of leaf alcohol described in this invention, the conversion rate of isoprene is 81.56 - 92.73%, the selectivity of cis-3-hexen-1-al is 80.69 - 88.13%, the yield of cis-3-hexen-1-al is 55.53 - 80.97%, the selectivity of leaf alcohol is 98.36 - 99.60%, the yield of leaf alcohol is 54.94 - 80.35% (calculated based on isoprene), and the purity of leaf alcohol is 99.2 - 99.50%.

[0010] Chinese Patent CN201310078325.7 discloses a method for comprehensive utilization of isoprene. The method includes the following steps: 1) The isoprene raw material enters a distillation column for distillation. Trans-isoprene is obtained at the top of the column, and a heavy fraction rich in cis-isoprene is obtained at the bottom of the column. 2) The bottom material obtained in step 1) undergoes an isomerization reaction. After the reaction, oil / water separation is carried out, and the upper oil phase is sent to a distillation column for distillation, while the water phase is recycled as a catalyst. 3) The oil phase obtained in step 2) is sent to a distillation column for distillation, and trans-isoprene is obtained at the top of the column. 4) The bottom material obtained in step 3) undergoes selective hydrogenation to convert a small amount of isoprene contained in the material into 2-pentene. 5) The hydrogenation reaction liquid obtained in step 4) is sent to a distillation column for distillation, and 2-pentene is obtained at the top of the column. 6) The bottom material obtained in step 5) is sent to a distillation column for distillation, and cyclopentene is obtained at the top of the column, while a heavy fraction rich in cyclopentane is obtained at the bottom of the column. 7) The bottom material obtained in step 6) undergoes hydrogenation. After hydrogenation, all the monoolefins in the material are converted into alkanes. 8) The hydrogenation reaction liquid obtained in step 7) is sent to a distillation column for distillation, and cyclopentane is obtained at the top of the column.

[0011] The methods for utilizing isoprene provided in the above patents are relatively simple, only single polymerization or separation, etc., and the products synthesized using isoprene are also relatively single. Summary of the Invention

[0012] In view of the above problems, the present invention provides a method for comprehensive utilization of piperylene. The present invention provides a new method for comprehensive utilization of piperylene, which not only opens up a new production line for the comprehensive utilization of piperylene, but also uses piperylene as a raw material to produce different new material chemicals with high added value, greatly improving the utilization value of piperylene.

[0013] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0014] A method for comprehensive utilization of piperylene, comprising the following steps: S1. Using piperylene as a raw material, carrying out selective hydrogenation under the action of a catalyst to generate n-pentene and 2-pentene; S2. The pentene obtained in step S1 reacts with syngas under the action of a rhodium-based catalyst and a carrier to carry out a hydroformylation reaction to generate n-hexanal and iso-hexanal, and the mixed hexanal is hydrogenated to obtain n-hexanol and iso-hexanol; S3. The n-hexanal and iso-hexanal obtained in step S2 carry out nucleophilic addition of the carbon-carbon double bond under the action of a basic catalyst, followed by deprotonation of the hydroxyl group to generate dodecenal, and finally the generated dodecenal is hydrogenated to obtain isododecanol.

[0015] Preferably, the main components of the catalyst used in S1 are palladium oxide and γ-aluminum oxide, gray particles, wherein the palladium content accounts for about 0.5%. Palladium as a catalyst can not only improve the reaction efficiency, but also inhibit the over-hydrogenation of piperylene into alkanes, thereby improving the selectivity of the reaction. γ-aluminum oxide as a carrier is abrasion-resistant and durable, and its surface is acidic, which can also promote the hydrogenation reaction; the rhodium-based catalyst in S2 is a rhodium carbonyl catalyst, and the carrier is triphenylphosphine. The rhodium carbonyl catalyst has relatively mild reaction conditions, can effectively reduce side reactions, improve the reaction efficiency and selectivity, and at the same time reduce the cost of separation and purification. Triphenylphosphine, as an electron-rich ligand, can maintain a strong coordination with the rhodium catalyst, reduce the loss of the rhodium catalyst, and moreover, triphenylphosphine forms a certain steric hindrance at the rhodium center, which can make the reaction proceed in a specific direction and improve the selectivity of the reaction.

[0016] Preferably, the dosage of the rhodium carbonyl catalyst is 0.05% of the mass of pentene, and the mass ratio of triphenylphosphine to the rhodium carbonyl catalyst is 500:1; a large amount of triphenylphosphine forms a certain steric hindrance at the rhodium center, affecting the approach mode of the reactants to the active center of the catalyst and the formation of the reaction transition state, thereby affecting the selectivity of the reaction. If the ratio is too large or too small, it will have a greater impact on the product selectivity.

[0017] Preferably, the reaction temperature in S1 is 80 °C, the reaction pressure is 1.2 MPa, and the hydrogen-oil molar ratio is 1.2:1; this temperature is suitable for the catalytic reaction of the palladium catalyst. Too high a temperature will cause the inactivation of the palladium catalyst. Too large a hydrogen-oil molar ratio will cause over-hydrogenation of piperylene, and too small a ratio will make the hydrogenation reaction incomplete.

[0018] Preferably, an appropriate amount of n-hexanal is added before the hydroformylation reaction in S2 to dissolve the catalyst and the carrier triphenylphosphine. Since the rhodium carbonyl catalyst is a homogeneous catalyst, a quantitative catalyst and ligand need to be dissolved with the product before the reaction to make their contact with the raw materials more sufficient and the reaction effect better.

[0019] Preferably, the mixed hydrogenation catalyst of n-hexanal and iso-hexanal in S2 is Raney nickel; the reaction pressure is 2.0 Mpa, the reaction temperature is 100 - 120 °C, and the hydrogen-oil ratio is 10:1. Too high reaction temperature will produce more side reactions, resulting in an increase in the separation and purification cost of hexanol in the later stage and a decrease in the quality of the hexanol product.

[0020] Preferably, the aldol condensation reaction in S3 needs to be carried out under a nitrogen atmosphere. Since aldehydes are extremely easy to oxidize in the air to generate many unnecessary impurities, the condensation reaction needs to be carried out in an air-free environment.

[0021] Preferably, the hydrogenation catalyst in S3 is a Raney nickel catalyst; the hydrogenation reaction temperature in S3 is 90 - 110 °C, the reaction pressure is 2 MPa, and the molar ratio of hydrogen to oil in the hydrogenation reaction is 10:1. Too high reaction temperature will produce more side reactions, resulting in an increase in the separation and purification cost of dodecanol in the later stage and a decrease in the product quality.

[0022] Preferably, the synthesis gas in S2 is hydrogen and carbon monoxide, and their molar ratio is 1:1; the hydroformylation reaction temperature in S2 is 60 - 80 °C, the reaction pressure is 2.0 Mpa, and the reaction time is 3 h; the molar ratio of the products n-hexanal and iso-hexanal formed by hydroformylation is 10:1. Too low reaction temperature and too short reaction time will reduce the reaction conversion rate, while too high reaction temperature and too long reaction time will reduce the reaction selectivity and the n-iso ratio of hexanal.

[0023] Preferably, the aldol condensation catalyst in S3 is a sodium hydroxide solution with a concentration of 2 mol / L, and the mass ratio of the catalyst used to the mass of the mixed hexanal is 1:1; the reaction temperature of the aldol condensation in S3 is 90 - 110 °C, the reaction pressure is 0.1 MPa, and the reaction time is 2 h. Too high reaction temperature and too long reaction time will increase the side reactions, while too low reaction temperature and too short reaction time will make the reaction incomplete.

[0024] The beneficial effects of the present invention are:

[0025] The present invention provides a new method for the comprehensive utilization of isoprene, opening up a new utilization mode for the comprehensive utilization of isoprene. Compared with the simple treatment and application of traditional isoprene, the present invention can create new material chemicals with multiple varieties and high added value, and also provides a new idea for the synthesis of C5 fatty alcohols in China. At the same time, the use of the hydroformylation catalyst in this method can greatly improve the selectivity of the reaction, making the product quality reach the international leading level. Compared with some high-temperature and high-pressure catalytic systems, the operating conditions of this catalyst are milder, which can greatly reduce the equipment requirements and production costs, and also improve the safety of the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart for the comprehensive utilization of isoprene of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described below in conjunction with the drawings and embodiments.

[0028] The present invention is a process technology for producing special alcohols by a series of processes such as hydrogenation, hydroformylation, and aldol condensation of isoprene, providing a new process for the comprehensive utilization of isoprene.

[0029] The technical solution of the present invention is as follows, including the following steps:

[0030] S1. Using isoprene as a raw material, selective hydrogenation is carried out under the action of a catalyst to generate n-pentene and 2-pentene.

[0031] S2. The obtained pentene undergoes a hydroformylation reaction with syngas under the action of a rhodium-based catalyst and a carrier to generate n-hexanal and iso-hexanal, and the mixed hexanal is then hydrogenated to obtain n-hexanol and iso-hexanol.

[0032] S3. The obtained n-hexanal and iso-hexanal undergo nucleophilic addition of the carbon-carbon double bond under the action of a basic catalyst, followed by deprotonation of the hydroxyl group to generate dodecenal, and finally the generated dodecenal is hydrogenated to obtain isododecanol.

[0033] Furthermore; the main components of the catalyst used in S1 are palladium oxide and γ-aluminum oxide, gray particles, and the palladium content is about 0.5%.

[0034] Furthermore; the reaction temperature in S1 is 80 °C, the reaction pressure is 1.2 MPa, and the hydrogen-oil molar ratio is 1.2:1.

[0035] The rhodium-based catalyst in S2 is a rhodium carbonyl catalyst, and the carrier is triphenylphosphine.

[0036] The dosage of the above rhodium carbonyl catalyst is 0.05% of the mass of pentene, and the mass ratio of triphenylphosphine to the rhodium carbonyl catalyst is 500:1.

[0037] Before the hydroformylation reaction in S2, an appropriate amount of n-hexanal was added to dissolve the catalyst and the carrier triphenylphosphine; the synthesis gas in S2 was hydrogen and carbon monoxide, and their molar ratio was 1:1; the temperature of the hydroformylation reaction in S2 was 60 - 80 °C, the reaction pressure was 2.0 Mpa, and the reaction time was 3 h; the molar ratio of the n-hexanal and iso-hexanal produced by the hydroformylation was 10:1.

[0038] The mixed hydrogenation catalyst of n-hexanal and iso-hexanal in S2 was Raney nickel; the reaction pressure was 2.0 Mpa, the reaction temperature was 100 - 120 °C, and the hydrogen-oil ratio was 10:1.

[0039] The aldol condensation reaction in S3 needed to be carried out under a nitrogen environment; the aldol condensation catalyst in S3 was a sodium hydroxide solution with a concentration of 2 mol / L, and the mass ratio of the catalyst used to the mass of the mixed hexanal was 1:1; the reaction temperature of the aldol condensation in S3 was 90 - 110 °C, the reaction pressure was 0.1 MPa, and the reaction time was 2 h.

[0040] The hydrogenation catalyst in S3 was a Raney nickel catalyst; the hydrogenation reaction temperature in S3 was 90 - 110 °C, the reaction pressure was 2 MPa, and the hydrogen-oil molar ratio of the hydrogenation reaction was 10:1.

[0041] The present invention will be further described below in conjunction with specific embodiments.

[0042] Example 1

[0043] 150 ml of a palladium and alumina mixed catalyst was loaded into a MRE-952||100 mL hydrogenation reaction device. 500 grams of piperylene was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 80 °C, a reaction pressure of 1.2 MPa, and a hydrogen-oil molar ratio of 1.2:1. After the product was rectified, 476.9 grams of 2-pentene and n-pentene were obtained; 200 grams of n-hexanal was added to a self-made hydroformylation reaction kettle, and then 0.24 grams of rhodium carbonyl catalyst, 119.2 grams of triphenylphosphine, and 476.9 grams of the prepared pentene were added. After purging with nitrogen three times and purging with synthesis gas once, the pressure was maintained at 2.0 MPa and the temperature was raised to 60 °C for reaction for 3 h. The generated product was separated to obtain 479.3 grams of n-hexanal and 59.9 grams of iso-hexanal; 150 ml of Raney nickel catalyst was loaded into a MRE-952||100 mL hydrogenation reaction device. 479.3 grams of n-hexanal and 59.9 grams of iso-hexanal prepared were added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 110 °C, a reaction pressure of 2 MPa, and a hydrogen-oil molar ratio of 10:1. After the product was rectified, 480.1 grams of n-hexanol and 60 grams of iso-hexanol were obtained.

[0044] Example 2

[0045] In the MRE-952||100 mL hydrogenation reaction device, 150 ml of a mixed catalyst of palladium and alumina was loaded. 500 grams of piperylene was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 80 °C, a reaction pressure of 1.2 MPa, and a hydrogen-oil molar ratio of 1.2:1. After rectifying the product, a total of 481.5 grams of 2-pentene and n-pentene were obtained; 200 grams of n-hexanal was added to a self-made hydroformylation reaction kettle, and then 0.24 grams of rhodium carbonyl catalyst, 119.7 grams of triphenylphosphine, and 481.5 grams of the prepared pentene were added. After purging with nitrogen three times and purging with syngas once, the pressure was maintained at 2.0 MPa and the temperature was raised to 70 °C for reaction for 3 h. The generated product was separated to obtain 500.5 grams of n-hexanal and 62.6 grams of isohexanal; 150 ml of Raney nickel catalyst was loaded into the MRE-952||100 mL hydrogenation reaction device, and 500.5 grams of n-hexanal and 62.6 grams of isohexanal prepared were added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 110 °C, a reaction pressure of 2 MPa, and a hydrogen-oil molar ratio of 10:1. After rectifying the product, 504.3 grams of n-hexanol and 63 grams of isohexanol were obtained as the product.

[0046] Example 3

[0047] In the MRE-952||100 mL hydrogenation reaction device, 150 ml of a mixed catalyst of palladium and alumina was loaded. 500 grams of piperylene was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 80 °C, a reaction pressure of 1.2 MPa, and a hydrogen-oil molar ratio of 1.2:1. After rectifying the product, a total of 483.5 grams of 2-pentene and n-pentene were obtained; 200 grams of n-hexanal was added to a self-made hydroformylation reaction kettle, and then 0.24 grams of rhodium carbonyl catalyst, 120.9 grams of triphenylphosphine, and 483.5 grams of the prepared pentene were added. After purging with nitrogen three times and purging with syngas once, the pressure was maintained at 2.0 MPa and the temperature was raised to 80 °C for reaction for 3 h. The generated product was separated to obtain 543.9 grams of n-hexanal and 68 grams of isohexanal; 150 ml of Raney nickel catalyst was loaded into the MRE-952||100 mL hydrogenation reaction device, and 543.9 grams of n-hexanal and 68 grams of isohexanal prepared were added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 110 °C, a reaction pressure of 2 MPa, and a hydrogen-oil molar ratio of 10:1. After rectifying the product, 545.9 grams of n-hexanol and 68.2 grams of isohexanol were obtained as the product.

[0048] Example 4

[0049] In the MRE-952||100 mL hydrogenation reaction device, 150 mL of a mixed catalyst of palladium and alumina was loaded. 500 g of piperylene was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 80 °C, a reaction pressure of 1.2 MPa, and a hydrogen-oil molar ratio of 1.2:1. After rectification of the product, 483 g of 2-pentene and n-pentene were obtained. 200 g of n-hexanal was added to a self-made hydroformylation reactor, and then 0.24 g of rhodium carbonyl catalyst, 120.7 g of triphenylphosphine, and 483 g of the prepared pentene were added. After purging with nitrogen three times and purging with syngas once, the pressure was maintained at 2.0 MPa and the temperature was raised to 80 °C for reaction for 3 h. The generated product was separated to obtain 540.8 g of n-hexanal and 67.6 g of isohexanal. 608.4 g of the prepared n-hexanal and isohexanal were added to a self-made reactor, and 608.4 g of 2 mol / L sodium hydroxide solution was added. After purging with nitrogen, the reaction pressure was maintained at 0.1 MPa and heated to 90 °C for reaction for 2 h. After separation, 455.4 g of the condensation product was obtained. 150 mL of Raney nickel catalyst was loaded into the MRE-952||100 mL hydrogenation reaction device, and 455.4 g of the prepared condensation product was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 110 °C, a reaction pressure of 2 MPa, and a hydrogen-oil molar ratio of 10:1. After rectification of the product, 500.2 g of isomeric dodecanol was obtained.

[0050] Example 5

[0051] Under the same conditions as in Example 4, 500 g of piperylene was taken and after hydrogenation and hydroformylation reactions, 544.3 g of n-hexanal and 68 g of isohexanal were prepared. 200 g of the prepared n-hexanal and isohexanal were added to a self-made reactor, and 612.3 g of 2 mol / L sodium hydroxide solution was added. After purging with nitrogen, the reaction pressure was maintained at 0.1 MPa and heated to 100 °C for reaction for 2 h. After separation, 478.9 g of the condensation product was obtained. 150 mL of Raney nickel catalyst was loaded into the MRE-952||100 mL hydrogenation reaction device, and 478.9 g of the prepared condensation product was added to the raw material tank. The hydrogenation reaction was carried out under the conditions of a reaction temperature of 110 °C, a reaction pressure of 2 MPa, and a hydrogen-oil molar ratio of 10:1. After rectification of the product, 514.6 g of isomeric dodecanol was obtained.

[0052] Example 6

[0053] Under the same conditions as in Example 4, 500 g of piperylene was taken and reacted through hydrogenation and hydroformylation to obtain 546.6 g of n-hexanal and 68.3 g of iso-hexanal; 200 g of the obtained n-hexanal and iso-hexanal were added to a self-made reaction kettle, 614.9 g of 2 mol / L sodium hydroxide solution was added, and after nitrogen replacement, the reaction pressure was maintained at 0.1 MPa, and it was heated to 110 °C and reacted for 2 h. After separation, 508.5 g of the condensation product was obtained; 150 ml of Raney nickel catalyst was loaded into the MRE-952||100 mL hydrogenation reaction device, 508.5 g of the obtained condensation product was added to the raw material tank, and the reaction temperature was set at 110 °C, and the reaction pressure was 2 MPa. The hydrogenation reaction was carried out under the condition of a hydrogen-oil molar ratio of 10:1. After the product was rectified, 531.3 g of the product isododecanol was obtained.

[0054] The parameter indexes of n-hexanol and iso-hexanol prepared in the above Examples 1-3 are shown in Table 1.

[0055] Table 1

[0056]

[0057] The parameter indexes of isododecanol prepared in the above Examples 4-6 are shown in Table 2.

[0058] Table 2

[0059]

[0060] Compared with the prior art, the present invention has the following beneficial technical effects:

[0061] The present invention provides a new method for comprehensive utilization of piperylene, opening up a new utilization mode for the comprehensive utilization of piperylene. Compared with the simple treatment and application of traditional piperylene, the present invention can create new material chemicals with multiple varieties and high added value, and also provides a new idea for the synthesis of C5 fatty alcohols in China. At the same time, the use of the hydroformylation catalyst in this method can greatly improve the selectivity of the reaction, making the product quality reach the international leading level. Compared with some high-temperature and high-pressure catalytic systems, the operating conditions of this catalyst are milder, which can greatly reduce the equipment requirements and production costs, and also improve the safety of the production process.

[0062] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for comprehensive utilization of piperylene, characterized in that: The steps include: S1, using piperylene as a raw material, selectively hydrogenating under the action of a catalyst to produce n-pentene and 2-pentene; S2, the pentene obtained in step S1 undergoes carbonyl synthesis reaction with synthesis gas under the action of a rhodium catalyst and a carrier to produce n-hexanal and isohexanal, and the mixed hexanal is then hydrogenated to produce n-hexanol and isohexanol; S3, the n-hexanal and isohexanal prepared in step S2 are subjected to nucleophilic addition of carbon-carbon double bonds under the action of an alkaline catalyst, followed by deprotonation of the hydroxyl group to produce dodecenal, and finally the produced dodecenal is hydrogenated to produce isomeric dodecanol.

2. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The catalyst used in S1 is mainly composed of palladium oxide and γ-aluminum oxide, and is gray particles, in which the palladium content is about 0.5%; the rhodium catalyst of S2 is a carbonyl rhodium catalyst, and the carrier is triphenylphosphine.

3. The method for comprehensive utilization of piperylene according to claim 2, characterized in that: The amount of carbonyl rhodium catalyst used is 0.05% of the mass of pentene, and the mass ratio of triphenylphosphine to carbonyl rhodium catalyst is 500:

1.

4. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The reaction temperature of S1 is 80°C, the reaction pressure is 1.2MPa, and the hydrogen-to-oil molar ratio is 1.2:

1.

5. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: Before the S2 carbonyl synthesis reaction, an appropriate amount of n-hexanal is added to dissolve the catalyst and the carrier triphenylphosphine.

6. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The mixed hydrogenation catalyst of n-hexanal and iso-hexanal in S2 is Raney nickel; the reaction pressure is 2.0 MPa, the reaction temperature is 100-120°C, and the hydrogen-to-oil ratio is 10:

1.

7. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The aldol condensation reaction in S3 needs to be carried out under a nitrogen environment.

8. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The S3 hydrogenation catalyst is a Raney nickel catalyst; the S3 hydrogenation reaction temperature is 90-110°C, the reaction pressure is 2MPa, and the hydrogen-to-oil molar ratio of the hydrogenation reaction is 10:

1.

9. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The synthesis gas of S2 is hydrogen and carbon monoxide, and the molar ratio is 1:1; the carbonyl synthesis reaction temperature in S2 is 60-80°C, the reaction pressure is 2.0Mpa, and the reaction time is 3h; the molar ratio of the products n-hexanal and iso-hexanal generated by carbonyl synthesis is 10:

1.

10. The method for comprehensive utilization of piperylene according to claim 1, characterized in that: The aldol condensation catalyst in S3 is a sodium hydroxide solution with a concentration of 2 mol / L, and the mass ratio of the catalyst used to the mixed hexanal is 1:1; the reaction temperature of the aldol condensation in S3 is 90-110°C, the reaction pressure is 0.1MPa, and the reaction time is 2h.

Images