Synthesis method of decahydronaphthalene

Abstract

The invention relates to a process technology for preparing decahydronaphthalene through catalytic hydrogenation by taking naphthalene as a raw material, adopting decahydronaphthalene as a solvent of a solid raw material naphthalene and adopting a platinum catalyst to synthesize decahydronaphthalene in one step in a reaction kettle at lower temperature and pressure, the reaction pressure is 0.1-0.5 MPa, the reaction temperature is 50-200 DEG C, the liquid hourly space velocity (LHSV) is 0.5, and the per pass conversion of naphthalene reaches 99.5% or above. The decahydronaphthalene selectivity reaches 99.5% or above, and the decahydronaphthalene yield reaches 99% or above.

Description

Technical Field

[0001] The invention belongs to the field of hydrogenation, and relates to a process technology for preparing decahydronaphthalene by catalytic hydrogenation with naphthalene as a raw material, using decahydronaphthalene as a solvent for solid raw material naphthalene and using a platinum catalyst to synthesize decahydronaphthalene in a reactor in one step at a relatively low temperature and pressure. Background Art

[0002] There have been many studies on the method of preparing decahydronaphthalene by hydrogenation of naphthalene as early as seventy or eighty years ago. For example, J.Soc.Chem.Ing., 1927, 46.454; Rec.trav.chim., 1934, 53.821 reported the reaction mechanism, process parameters, and the effects of various catalysts on the preparation of decahydronaphthalene by hydrogenation of naphthalene. There are still many research reports in recent years, for example: Huang, Ting-Chia; Kang, Ben-Chang. Ind. Eng. Chem. Res., 34 (4), 1140-8 and 34 (7), 2349-57, 1995.; Rautanen, PA; Aittamaa, JR; Krause, AOI; Chem. Eng. Sci., 56 (4), 1247-1254, 2001., etc. studied the reaction kinetics of naphthalene hydrogenation to produce decahydronaphthalene; Fumio Kumada and Yoshiro Hirasawa reported "a method for producing decahydronaphthalene by two-step hydrogenation of naphthalene" in Japanese patent JP160515A published on June 3, 2003. The method is: naphthalene is hydrogenated to produce tetrahydronaphthalene in the first step, the product is separated by distillation, and then the tetrahydronaphthalene is hydrogenated to produce decahydronaphthalene in the second step. In the patent application with application number 200310106565.X, tetralin is used as the solvent of the solid raw material naphthalene, and a nickel-based catalyst is used to synthesize decalin in a reactor at a relatively low temperature and pressure in one step. The reaction pressure is 6-12 MPa, the reaction temperature is 180-220°C, and the liquid hourly space velocity (LHSV) is 0.5-1. The conversion rate of naphthalene reaches more than 98%, the yield of decalin reaches 98%, and the yield of by-products is less than 1%. However, the reaction pressure is relatively high, the energy consumption is large, and the equipment investment is large. Summary of the invention

[0003] Purpose of the invention: It is difficult to further hydrogenate naphthalene to decahydronaphthalene, especially in the process of hydrogenating decahydronaphthalene, high hydrogen pressure and longer reaction time are required. The purpose of the present invention is to select tungsten oxide supported platinum catalyst to directly hydrogenate decahydronaphthalene at relatively low pressure and temperature, so as to improve the naphthalene single-pass conversion rate and decahydronaphthalene selectivity.

[0004] Technical solution: The present invention uses naphthalene as a raw material to catalytically hydrogenate decalin, and uses a platinum catalyst to synthesize decalin in one step in a high-pressure stirred reactor under relatively low pressure and temperature conditions.

[0005] Main technical solution: A method for synthesizing decahydronaphthalene, which uses naphthalene as a raw material to catalytically hydrogenate decahydronaphthalene, and is characterized in that naphthalene is dissolved in decahydronaphthalene as a solvent, and a catalytic hydrogenation reaction is carried out under the action of a catalyst to synthesize decahydronaphthalene.

[0006] Generally, the reaction pressure is 0.1~0.5 Mpa.

[0007] The reaction temperature is 50-200°C.

[0008] The liquid volume space velocity is 0.5~0.6h -1 The reaction is carried out under the conditions of .

[0009] The catalyst is composed of platinum and a tungsten oxide carrier.

[0010] Preferably, the mass content of platinum in the catalyst is 0.1-0.6%, and the rest is tungsten oxide carrier.

[0011] Preferably, the catalyst is prepared by loading platinum onto a carrier using an impregnation method.

[0012] The dosage ratio of naphthalene:decalin:catalyst is 1:2-3:1.

[0013] The product decalin produced by the present invention is used as a solvent for recycling.

[0014] The decalin synthesis method provided by the present invention has a single-pass conversion rate of naphthalene of more than 99.5%, a decalin selectivity of more than 99.5%, and a decalin yield of more than 99%.

[0015] Compared with the prior art, the method for preparing decalin provided by the present invention greatly reduces the reaction pressure and can even be carried out under normal pressure. The equipment investment and reaction energy consumption are greatly reduced, and the reaction safety is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 Schematic diagram of the synthesis method of the present invention. Implementation

[0017] The present invention is described in detail below in conjunction with embodiments and drawings. Example

[0018] Process The process is as attached Figure 1 As shown: a certain amount of raw materials (naphthalene and solvent) and catalyst are added into the reactor and heated to the set temperature. The reaction is carried out under different hydrogen pressure conditions. After the reaction is completed, the naphthalene single-pass conversion rate, decalin selectivity and decalin yield under different pressure conditions are analyzed.

[0019] Reaction steps In a high-pressure stirred reactor, refined naphthalene was used as raw material, suitable catalysts were screened, and the single-pass conversion rate of naphthalene and the yield of decalin were tested at different reaction temperatures and pressures.

[0020] Reaction conditions: pressure 0.1~0.5MPa; temperature: 50~200℃, reaction time per kettle: 5~10 hours.

[0021] Main ingredients: Refined naphthalene GB6699-86 (first grade) content ≥99% Hydrogen content ≥99.5% Platinum catalyst Pt / WO Carbon tetrachloride analysis content ≥98% Decalin industrial grade one content ≥98% Main instruments and equipment High-pressure hydrogenation reactor Reactor specifications: 0.5L / 25Mpa (316 thickened type) one set A set of distillation equipment Two pressure regulating valves Thyristor voltage adjustment and temperature controller set A gas chromatograph A set of dual-channel chemical workstation Test results The tungsten oxide-supported platinum catalyst in the method of the present invention has a high naphthalene single-pass conversion rate and decalin selectivity within the reaction temperature range of 50-200° C. and the pressure range of 0.1 MPa-0.5 MPa, and as the reaction pressure decreases, the naphthalene single-pass conversion rate and decalin selectivity are slightly improved.

[0022] Effect of catalyst type Experimental data show that, compared with platinum catalysts and nickel-molybdenum catalysts, platinum catalysts have good low-temperature activity, which is beneficial to lowering the reaction temperature, reducing the production of side reactants, and shortening the reaction time. Example 1

[0023] 50 g of naphthalene, 100 g of decalin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 160°C and reaction pressure of 0.5 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 99.8%, the selectivity of decalin reached 99.8%, and the yield of decalin reached 99.5%. Example 2

[0024] 50 g of naphthalene, 150 g of decalin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 160°C and reaction pressure of 0.3 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 99.5%, the selectivity of decalin reached 99.8%, and the yield of decalin reached 99.2%. Example 3

[0025] 50 g of naphthalene, 150 g of decalin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 180°C and reaction pressure of 0.2 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 99.6%, the selectivity of decalin reached 99.8%, and the yield of decalin reached 99.1%. Example 4

[0026] 50 g of naphthalene, 150 g of decalin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 180°C and reaction pressure of 0.2 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 99.6%, the selectivity of decalin reached 99.5%, and the yield of decalin reached 99%. Example 5

[0027] 50 g of naphthalene, 150 g of decalin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. The reaction temperature was 180°C, and under normal pressure, the liquid hourly space velocity (LHSV) was 0.5. The single-pass conversion rate of naphthalene reached 99.6%, the selectivity of decalin reached 99.5%, and the yield of decalin reached 99.2%.

[0028] Comparative Example 1: 50 g of naphthalene, 150 g of tetralin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 190°C and reaction pressure of 4 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 88.5%, the selectivity of decalin was 95.0%, and the yield of decalin was 86%.

[0029] Comparative Example 2: 50 g of naphthalene, 150 g of tetralin and 50 g of platinum catalyst were added to a high-pressure stirred reactor. Under the conditions of reaction temperature of 180°C and reaction pressure of 7 MPa, the liquid hourly space velocity (LHSV) was 0.5, the single-pass conversion rate of naphthalene reached 95.5%, the selectivity of decalin was 96.5%, and the yield of decalin was 92.5%.

Claims

1. A method for synthesizing decahydronaphthalene, which is to use naphthalene as a raw material and catalytically hydrogenate decahydronaphthalene, characterized in that Decalin is synthesized by dissolving naphthalene in decahydronaphthalene as a solvent and carrying out a catalytic hydrogenation reaction under the action of a catalyst.

2. The synthetic method of decalin as claimed in claim 1, characterized in that The reaction pressure is 0.1~0.5 Mpa.

3. The synthetic method of decalin as claimed in claim 1, characterized in that Reaction temperature 50~200℃.

4. The synthetic method of decalin as claimed in claim 1, characterized in that Liquid volume space velocity is 0.5~0.6h -1 The reaction is carried out under the conditions of .

5. The synthetic method of decalin as claimed in claim 1, characterized in that The catalyst is composed of platinum and a tungsten oxide carrier.

6. The synthetic method of decalin as claimed in claim 5, characterized in that The mass content of platinum in the catalyst is 0.1-0.6%, and the rest is tungsten oxide carrier.

7. The synthetic method of decalin as claimed in claim 5 or 6, characterized in that The catalyst adopts an impregnation method to load platinum on a carrier.

8. The synthetic method of decalin as claimed in claim 1, characterized in that The generated product is recycled as solvent.

9. The synthetic method of decalin as claimed in claim 1, characterized in that Naphthalene: The dosage ratio of decahydronaphthalene:catalyst is 1:2~3:

1.

10. The method for synthesizing decalin as claimed in claim 1, characterized in that The single-pass conversion rate of naphthalene is above 99.5%, the selectivity of decalin is above 99.5%, and the yield of decalin is above 99%.

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