Method for preparing perhydrophenanthrene by phenanthrene hydrogenation through two-step method

Abstract

The invention discloses a method for preparing perhydrophenanthrene by phenanthrene hydrogenation through a two-step method, and solves the problems of high subsequent separation energy consumption, high reaction temperature and poor safety caused by use of a solvent in the prior art. The invention adopts a solvent-free two-step hydrogenation method which comprises the following steps: step 1, under a solvent-free condition, carrying out primary hydrogenation by taking solid phenanthrene as a raw material and adopting a non-noble metal catalyst to obtain an unsaturated liquid product octahydrophenanthrene; and 2, carrying out a deep hydrogenation reaction on the unsaturated liquid product and a noble metal catalyst to finally obtain perhydrophenanthrene. According to the method, no solvent is used, the technological process is simplified, and production energy consumption and equipment investment are reduced; the catalyst combination of non-noble metal and noble metal is adopted, and the catalyst can be recycled, so that the production cost is remarkably reduced; meanwhile, the reaction conditions are mild, and the production safety and the perhydrophenanthrene cis-isomer selectivity are improved. The method is suitable for large-scale and economic preparation of high-energy-density aviation fuel precursors, namely perhydrophenanthrene and octahydrophenanthrene.

Description

Technical Field

[0001] This invention relates to the field of hydrogenation technology for polycyclic aromatic hydrocarbons, and specifically to a two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene. Background Technology

[0002] High-energy-density aviation fuel refers to fuel with a density >0.8 g / cm³. 3 Aviation fuels with a calorific value >32 MJ / L are widely used in aircraft, missiles, rockets, and other aircraft. Developing high-density aviation fuels is of great significance for enhancing my country's national defense capabilities. Naphthalene, acenaphthene, acenaphthene, fluorene, phenanthrene, anthracene, and other polycyclic aromatic hydrocarbons and their alkyl-substituted derivatives are the main components of petroleum refining residues and coal liquefaction tar. Their carbon atom numbers are similar to those of aviation fuels, indicating potential for producing high-energy-density aviation fuels. The density of total hydrogen phenanthrene is approximately 0.93 g / cm³. 3 Its calorific value is approximately 42.6 MJ / L, which meets the requirements for high energy density fuels.

[0003] However, polycyclic aromatic hydrocarbons are mostly solid at room temperature, and direct hydrogenation to prepare perhydrophenanthrene presents technical challenges. Existing technologies, such as the methods disclosed in CN113368891A and CN117816193A, typically involve dissolving phenanthrene in solvents such as decahydronaphthalene for the hydrogenation reaction, at temperatures as high as 260°C to 300°C. While these methods achieve the hydrogenation conversion of phenanthrene, they suffer from the following significant drawbacks: (1) Use of large amounts of solvent: The reaction process requires the use of solvent to dissolve solid raw materials, which leads to complex and energy-intensive subsequent product separation processes; (2) High reaction temperature: High temperature conditions not only consume a lot of energy, but also pose safety hazards; (3) High catalyst cost: Some methods rely on precious metal catalysts, and the catalyst recycling is insufficient, which increases production costs.

[0004] Therefore, developing an efficient method for the hydrogenation of phenanthrene to produce all-hydrophenanthrene without solvents, under mild reaction conditions, and with recyclable catalysts has significant industrial application value. Summary of the Invention

[0005] The purpose of this invention is to provide a two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene, in order to solve the technical problems of high energy consumption, high reaction temperature and poor safety in the subsequent separation caused by the use of solvents in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene, comprising the following steps: S1. Under solvent-free conditions, add solid phenanthrene to the reactor, add a non-precious metal catalyst, and seal the reactor. S2. First, replace the air inside the reactor with nitrogen three times, then replace the nitrogen with hydrogen three times. S3. Open the reactor and add non-precious metal catalyst, then close the reactor and repeat step S2. S4. Open the reaction vessel, filter and separate the liquid product and catalyst, recover and reuse the catalyst, add granular anhydrous magnesium sulfate to the liquid product under stirring to remove the water brought in by the catalyst, and obtain an unsaturated liquid product. S5. Add the unsaturated liquid product obtained in step S4 and the noble metal catalyst into the reactor, and seal the reactor. S6. First, replace the air in the reactor with nitrogen three times, then replace the nitrogen with hydrogen three times. S7. Open the reactor, filter and separate the liquid product and catalyst. The catalyst is washed and dried with ethanol and reused. The resulting liquid product is perhydrophenanthrene.

[0007] Furthermore, the non-precious metal catalyst is a Raney nickel catalyst, and the precious metal catalyst is a ruthenium-based catalyst.

[0008] Furthermore, the ruthenium-based catalyst is a Ru / C catalyst.

[0009] Furthermore, in step S3, the mass ratio of the solid phenanthrene to the non-precious metal catalyst is 1:0.1-0.3.

[0010] Furthermore, in step S5, the mass ratio of the unsaturated liquid product to the noble metal catalyst is 1:0.02-0.06.

[0011] Further, in step S2, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 5 MPa, react for 3 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

[0012] Further, in step S3, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 5 MPa, react for 6 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

[0013] Further, in step S6, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 6 MPa, react for 27 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

[0014] Based on the above technical solution, the embodiments of the present invention can produce at least the following technical effects: (1) The two-step hydrogenation method adopted in this invention is suitable for hydrogenation saturation of solid polycyclic aromatic hydrocarbons. It does not require the use of solvent to dissolve solid raw materials, so there is no need to separate the product from the solvent in the subsequent process. The process is simple, greatly reducing the energy consumption of the production of all-hydrophenanthrene and reducing the investment in production equipment.

[0015] (2) The two-step hydrogenation method for preparing full-hydrophenanthrene provided by the present invention uses a cheap non-precious metal catalyst for the first step of preliminary hydrogenation and a precious metal catalyst for the second step of deep hydrogenation. Both catalysts can be recycled and reused, reducing the amount of precious metal catalyst used. At the same time, the reaction temperature is low, which reduces the production cost and improves the production safety. It also achieves a high yield of full-hydrophenanthrene and is suitable for large-scale and economical production of high-energy-density aviation fuel precursors.

[0016] (3) The phenanthrene hydrogenation products are diverse, and can selectively generate octahydrophenanthrene or selectively generate the cis isomer perhydrophenanthrene. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a gas chromatogram of the six stereoisomers of all-hydrophenanthrene according to an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0020] Example 1 This embodiment provides a two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene, including the following steps: Step 1: Hydrogenation: Add 500g of phenanthrene to the reactor, add 150g of Raney nickel catalyst, seal the reactor, purge with nitrogen three times, purge with nitrogen to 1MPa, heat to 110℃, start stirring at 150rpm, purge with nitrogen three times, then purge with hydrogen three times, purge with hydrogen to 3MPa, heat to 200℃, adjust stirring speed to 600rpm, adjust hydrogen pressure to 5MPa, react for 3 hours, cool to room temperature, discharge hydrogen, purge with nitrogen three times, open the reactor, add 100g of Raney nickel catalyst, seal the reactor, purge with nitrogen three times, purge with hydrogen three times, purge with hydrogen to 3MPa, start stirring at 600rpm, heat to 200℃, adjust hydrogen pressure to 5MPa, react for 6 hours, cool to room temperature, discharge hydrogen, purge with nitrogen three times, open the reactor and use a Buchner funnel to filter and separate the liquid product and catalyst. The catalyst can be recycled and reused. A suitable amount of granular anhydrous magnesium sulfate was added to the liquid product under stirring to remove water introduced by the Raney nickel catalyst. The anhydrous liquid product was obtained by filtration through a Buchner funnel. Chromatographic / mass spectrometric analysis of phenanthrene conversion, symmetric octahydrophenanthrene (sym-OHP) selectivity, asymmetric octahydrophenanthrene (asym-OHP) selectivity, and perhydrophenanthrene (PHP) selectivity are shown in Table 1. Figure 1 Gas chromatograms of six stereoisomers of phenanthrene are presented. The first stereoisomer detected in the chromatograms is the trans isomer, which has lower density and heat of combustion. Meanwhile, the higher-density cis isomer appears later in the chromatogram and is an ideal component for jet fuel.

[0021] Table 1 Results of the first step hydrogenation reaction The second step, hydrogenation, involves adding the liquid product to a reactor, followed by 4 wt% of the liquid product in a 5 wt% Ru / C catalyst. The reactor is then sealed, purged with nitrogen three times, followed by hydrogen purging three times. Hydrogen pressure is introduced to 3 MPa, stirring is started at 600 rpm, and the temperature is raised to 200°C. The hydrogen pressure is then adjusted to 6 MPa, and the reaction is carried out for 27 hours. After cooling to room temperature, the hydrogen is released, and the reactor is purged with nitrogen three times. The liquid product and catalyst are then separated using a sintered glass funnel. The catalyst can be reused after washing and drying with ethanol. The resulting liquid product is perhydrophenanthrene. Chromatographic / mass spectrometric analysis showed a perhydrophenanthrene yield of 99.00%. The selectivity of the six isomers is shown in Table 2.

[0022] Table 2 Results of the second step hydrogenation reaction Comparative Example 1 The first step, hydrogenation, is the same as that used in Example 1.

[0023] The second step, hydrogenation, involves adding the liquid product to a reactor, followed by 8 wt% Raney nickel catalyst (containing the promoting component Cr). The reactor is then sealed, purged with nitrogen three times, followed by hydrogen purging three times. Hydrogen pressure is increased to 3 MPa, stirring is initiated at 600 rpm, and the temperature is raised to 200°C. The hydrogen pressure is then adjusted to 6 MPa, and the reaction is carried out for 4 hours. After cooling to room temperature, the hydrogen is released, and the reactor is purged with nitrogen three times. The liquid product and catalyst are then separated using a sintered glass funnel. The catalyst can be reused after washing and drying. The resulting liquid product is perhydrophenanthrene. Chromatographic / mass spectrometric analysis showed a perhydrophenanthrene yield of 99.09%. The selectivity of the six isomers is shown in Table 3.

[0024] Table 3 Results of the second-step hydrogenation reaction Compared to Raney nickel catalysts (containing the promoting component Cr), Ru / C catalysts yielded 38.88% higher CSC-PHP content and 0.0124 g·mL higher density of the total phenanthrene hydrogen obtained through hydrogenation. -1 .

[0025] Comparative Example 2 Step 1: Hydrogenation: Add 500g of phenanthrene to the reactor, add 100g of Raney nickel catalyst, seal the reactor, purge with nitrogen three times, purge with nitrogen to 1MPa, heat to 110℃, start stirring at 150rpm, purge with nitrogen three times, then purge with hydrogen three times, purge with hydrogen to 3MPa, heat to 200℃, adjust stirring speed to 600rpm, adjust hydrogen pressure to 5MPa, react for 3 hours, cool to room temperature, discharge hydrogen, purge with nitrogen three times, open the reactor, add 150g of Raney nickel catalyst, seal the reactor, purge with nitrogen three times, purge with hydrogen three times, purge with hydrogen to 3MPa, start stirring at 600rpm, heat to 200℃, adjust hydrogen pressure to 5MPa, react for 6 hours, cool to room temperature, discharge hydrogen, purge with nitrogen three times, open the reactor and use a Buchner funnel to filter and separate the liquid product and catalyst. The catalyst can be recycled and reused. A suitable amount of granular anhydrous magnesium sulfate was added to the liquid product under stirring to remove water introduced by the Raney nickel catalyst. The anhydrous liquid product was obtained by filtration through a Buchner funnel. Chromatographic / mass spectrometric analysis of phenanthrene conversion, symmetric octahydrophenanthrene (sym-OHP) selectivity, asymmetric octahydrophenanthrene (asym-OHP) selectivity, and perhydrophenanthrene (PHP) selectivity are shown in Table 4. Table 4 Results of the first step hydrogenation reaction The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene, characterized in that, Includes the following steps: S1. Under solvent-free conditions, add solid phenanthrene to the reactor, add a non-precious metal catalyst, and seal the reactor. S2. First, replace the air inside the reactor with nitrogen three times, then replace the nitrogen with hydrogen three times. S3. Open the reactor and add non-precious metal catalyst, then close the reactor. First, replace the air in the reactor with nitrogen three times, then replace the nitrogen with hydrogen three times. S4. Open the reaction vessel, filter and separate the liquid product and catalyst, recover and reuse the catalyst, add granular anhydrous magnesium sulfate to the liquid product under stirring to remove the water brought in by the catalyst, and obtain an unsaturated liquid product. S5. Add the unsaturated liquid product obtained in step S4 and the noble metal catalyst into the reactor, and seal the reactor. S6. First, replace the air in the reactor with nitrogen three times, then replace the nitrogen with hydrogen three times. S7. Open the reactor, filter and separate the liquid product and catalyst. The catalyst is washed and dried with ethanol and reused. The resulting liquid product is perhydrophenanthrene.

2. The method for preparing perhydrophenanthrene via two-step hydrogenation of phenanthrene according to claim 1, characterized in that, The non-precious metal catalyst is a Raney nickel catalyst, and the precious metal catalyst is a ruthenium-based catalyst.

3. The two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene according to claim 2, characterized in that, The ruthenium-based catalyst is a Ru / C catalyst.

4. The method for preparing perhydrophenanthrene via two-step hydrogenation of phenanthrene according to claim 1, characterized in that, In step S3, the mass ratio of the solid phenanthrene to the non-precious metal catalyst is 1:0.1-0.

3.

5. The method for preparing perhydrophenanthrene via two-step hydrogenation of phenanthrene according to claim 1, characterized in that, In step S5, the mass ratio of the unsaturated liquid product to the noble metal catalyst is 1:0.02-0.

06.

6. The method for preparing perhydrophenanthrene via two-step hydrogenation of phenanthrene according to claim 1, characterized in that, In step S2, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 5 MPa, react for 3 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

7. The method for preparing perhydrophenanthrene via two-step hydrogenation of phenanthrene according to claim 1, characterized in that, In step S3, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 5 MPa, react for 6 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

8. The two-step method for preparing perhydrophenanthrene by hydrogenation of phenanthrene according to claim 1, characterized in that, In step S6, the specific steps of first replacing the air in the reactor with nitrogen three times and then replacing the nitrogen with hydrogen three times are as follows: fill with nitrogen to 1 MPa, heat to 110°C, start stirring at 150 rpm, replace with nitrogen three times and then replace with hydrogen three times, fill with hydrogen to 3 MPa, heat to 200°C, adjust the stirring speed to 600 rpm, adjust the hydrogen pressure to 6 MPa, react for 27 hours, cool to room temperature and then discharge the hydrogen, and replace with nitrogen three times.

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