Method for synthesizing 1-chlorobutane through fixed bed gas-solid catalytic reaction

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 1-chlorobutane through a fixed bed gas-solid catalytic reaction. The method comprises the following steps: filling an activated carbon supported catalyst into a fixed bed reactor; the active components of the active carbon supported catalyst are composed of ZnCl2, FeCl3 and KCl; preheated hydrogen chloride and vaporized n-butyl alcohol are introduced into a fixed bed reactor and are in contact with the activated carbon supported catalyst for a catalytic reaction, mixed gas containing 1-chlorobutane is obtained, and the mixed gas is cooled and then subjected to gas-liquid separation to obtain 1-chlorobutane. According to the method, n-butyl alcohol and hydrogen chloride are taken as raw materials, a fixed bed reactor is filled with the active carbon supported catalyst, gas-solid catalytic reaction is carried out, 1-chlorobutane is continuously produced, and many defects existing in an existing 1-chlorobutane liquid phase method production route and a gas phase method using aluminum oxide and a molecular sieve catalyst are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and specifically relates to a method for synthesizing 1-chlorobutane through a fixed-bed gas-solid catalytic reaction. Background Art

[0002] Currently, the preparation methods of 1-chlorobutane include zinc chloride-catalyzed concentrated hydrochloric acid chlorination, thionyl chloride chlorination, phosphorus trichloride chlorination, and triphenylphosphine-catalyzed sodium chloride chlorination. All of the above preparation methods are liquid phase reactions. The substitution reaction of hydrogen chloride and n-butanol is slow. In the traditional process, zinc chloride needs to be used as a catalyst in this liquid system, which will produce a large amount of salt-containing wastewater that is difficult to treat. Subsequent improvements in the existing technology use thionyl chloride, phosphorus trichloride, ionic liquids, etc. as catalysts or reaction aids, but it is difficult to avoid the shortcomings of the liquid phase method itself: back-mixing of products and raw materials and intermittent reaction. Back-mixing will lead to a continuous decrease in the concentration of reactants, further slowing the reaction rate, long reaction time and low instantaneous yield; and the intermittent reaction process is not conducive to continuous production and has low production efficiency.

[0003] Patent CN104326863A discloses a method for preparing 1-chlorobutane. This method uses hydrogen chloride and n-butanol as raw materials, using dimethyl sulfoxide as a catalyst. Hydrogen chloride gas is introduced into the reaction residue to increase the concentration of hydrogen chloride for reuse. The chlorination reaction in this method is slow, requiring 20-24 hours, making it unsuitable for industrial application.

[0004] To solve the technical problems existing in the above-mentioned liquid system, existing fixed-bed catalytic technology is used for the preparation of 1-chlorobutane. For example, patent CN118666633A discloses a method for the continuous synthesis of 1-chlorobutane by fixed-bed catalytic oxidation. This method uses aluminum oxide or molecular sieve carriers to impregnate nickel, lanthanum, aluminum, and copper metal salt ions to prepare a catalyst. Catalysts are the core of fixed-bed gas-solid catalytic reaction technology, but in the above-mentioned technology, the processing of waste aluminum oxide and molecular sieve catalysts becomes a problem and generally requires landfill disposal. At the same time, the prices of the carrier aluminum oxide, molecular sieve, and the active component raw materials lanthanum salt and nickel salt are relatively high, greatly increasing production costs. Summary of the Invention

[0005] The object of the present invention is to address the above-mentioned defects and provide a method for synthesizing 1-chlorobutane by a fixed-bed gas-solid catalytic reaction. The method uses n-butanol and hydrogen chloride as raw materials, loads the activated carbon-supported catalyst in a fixed-bed reactor, and conducts a gas-solid catalytic reaction to continuously produce 1-chlorobutane. This method overcomes many shortcomings of the existing 1-chlorobutane liquid phase production route and the gas phase process using alumina and molecular sieve catalysts.

[0006] The specific technical solutions are as follows: A method for synthesizing 1-chlorobutane by a fixed-bed gas-solid catalytic reaction comprises the following steps: (1) Loading the activated carbon-supported catalyst into a fixed bed reactor; The active components of the activated carbon-supported catalyst are ZnCl2, FeCl3, and KCl; the mass ratio of ZnCl2:FeCl3:KCl is 1:(0.05-0.2):(0.05-0.15). FeCl3 can adjust the acidity of the catalyst, improve the selectivity of the reaction, and increase the yield. The potassium in KCl can effectively reduce carbon deposits generated by the catalytic reaction and extend the catalyst life.

[0007] The active components are uniformly loaded on the surface and pores of the carrier activated carbon, and the loading amount of the active components is 15%-20% of the total mass of the activated carbon-loaded catalyst.

[0008] (2) introducing preheated hydrogen chloride and vaporized n-butanol into a fixed bed reactor to contact the activated carbon-supported catalyst, wherein the molar ratio of hydrogen chloride to n-butanol is (1-2):1; When the reaction temperature is 150-250℃, the reaction pressure is 0.01-0.5MPa and the n-butanol space velocity is (0.1-2)h -1 The catalytic reaction is carried out under the conditions of , to obtain a mixed gas containing 1-chlorobutane, and the mixed gas is cooled and then subjected to gas-liquid separation to obtain 1-chlorobutane.

[0009] In the present invention, in the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, the activated carbon-supported catalyst in step (1) is a cylindrical particle of Φ5 mm × (4-7) mm.

[0010] In the present invention, in the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, the activated carbon-supported catalyst in step (1) is prepared by the following steps: 1) Activated carbon is added to a nitric acid solution, stirred, filtered, washed with deionized water until neutral, and dried to obtain an activated carbon carrier; the activated carbon soaked in nitric acid can significantly increase the number of oxygen-containing groups on the activated carbon surface, enhance the surface polarity, and significantly improve the adsorption performance.

[0011] Activated carbon is produced through pyrolysis and activation of carbon-containing raw materials such as wood, coal, and petroleum coke. Widely available and inexpensive, it possesses a well-developed pore structure, a large specific surface area, and a rich variety of surface chemical groups. This allows it to anchor active metal components while also improving the dispersion of these metal components. Furthermore, carbon materials can be completely combusted, and when the catalyst is deactivated, a combustion aid can be added for direct combustion.

[0012] 2) Add ZnCl2, FeCl3 and KCl to deionized water and stir evenly to prepare a mixed salt solution.

[0013] 3) impregnating the activated carbon support obtained in step 1) into the mixed salt solution obtained in step 2), stirring and then allowing to stand, evaporating the solvent in a water bath, and then drying to obtain the activated carbon-supported catalyst.

[0014] In the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, in step 1) of preparing the activated carbon-supported catalyst, each gram of activated carbon is added to 1.5-2.5 mL of nitric acid solution; wherein the concentration of the nitric acid solution is 1-12 mol / L.

[0015] Preferably, in step 1) of preparing the activated carbon-supported catalyst, each gram of activated carbon is added to 2 mL of nitric acid solution, wherein the concentration of the nitric acid solution is 4-10 mol / L.

[0016] Preferably, in step 1) of preparing the activated carbon-supported catalyst, the stirring speed is 50 rpm-100 rpm, the stirring time is 4 h-6 h, and the drying time is 4 h-6 h.

[0017] Preferably, in step 3) of preparing the activated carbon-supported catalyst, the standing time is 1 h to 4 h, and the drying time is 4 h to 6 h.

[0018] In the present invention, in the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, the preheating temperature of hydrogen chloride in step (2) is 160-230°C, and the vaporization temperature of n-butanol is 160-230°C.

[0019] In the present invention, the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, the specific operations of cooling and gas-liquid separation in step (2) are as follows: First, the obtained mixed gas containing 1-chlorobutane is cooled by heat exchange at a temperature of 10-25°C in a condenser; Then, the cooled mixed gas containing 1-chlorobutane is separated into gas and liquid using a gas-liquid separator to obtain a mixed liquid phase and a gas phase; the material of the gas-liquid separator can be fluorine-lined stainless steel 316L; wherein the gas phase is treated with alkali solution and the unreacted hydrogen chloride contained therein is absorbed by the alkali solution; The obtained mixed liquid phase is allowed to stand for stratification, and the upper organic phase is the product 1-chlorobutane.

[0020] In the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction of the present invention, the fixed-bed reactor is a tubular fixed-bed reactor with a specification of Φ38mm×4mm×2000mm. The material of the fixed-bed reactor can be 316L.

[0021] The beneficial effects of the present invention are as follows: the method for synthesizing 1-chlorobutane by a fixed-bed gas-solid catalytic reaction of the present invention uses n-butanol and hydrogen chloride as raw materials, loads the activated carbon-supported catalyst in a fixed-bed reactor, and conducts a gas-solid catalytic reaction to continuously produce 1-chlorobutane, thereby overcoming many shortcomings of the existing 1-chlorobutane liquid phase production route and the gas phase process using alumina and molecular sieve catalysts.

[0022] The provided 1-chlorobutane synthesis method uses an activated carbon-supported catalyst prepared by impregnating active components composed of zinc chloride, ferric chloride, and potassium chloride onto the surface and pores of an activated carbon support. No high-temperature calcination is required after impregnation, thus avoiding the generation of toxic and hazardous waste gases. Activated carbon, as a biomass material, is widely available, and waste activated carbon catalysts can be recycled by incineration, which is environmentally friendly. The catalyst is simple to prepare and is environmentally friendly and low-cost. Furthermore, the catalyst can withstand long-term production while maintaining stable performance, significantly reducing the production cost of industrial 1-chlorobutane synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The gas chromatogram of the product 1-chlorobutane obtained in Example 1 is shown.

[0024] Figure 2 This is a graph showing the change in yield of 1-chlorobutane prepared in Example 1 over time. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the embodiments, comparative examples and accompanying drawings.

[0026] In the various embodiments and comparative examples of the present invention, the raw materials and reagents used are all existing commercially available raw materials and reagents, and their specific sources are not repeated here.

[0027] Example 1 The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction comprises the following specific steps: (1) Preparation of activated carbon-supported catalyst: First, 10 kg of activated carbon was added to 20 L of 5 mol / L nitric acid solution, stirred for 5 h, filtered, washed with deionized water until neutral, and then dried for 5 h to obtain an activated carbon carrier.

[0028] Then, 1.7 kg of zinc chloride, 0.2 kg of ferric chloride, and 0.2 kg of potassium chloride were added to deionized water to prepare 5 L of a mixed salt solution; wherein the mass ratio of zinc chloride:ferric chloride:potassium chloride was 1:0.12:0.12.

[0029] Finally, the activated carbon support was immersed in the mixed salt solution, stirred evenly, and allowed to stand for 4 hours. The solvent was evaporated in a water bath, and dried to obtain the activated carbon-supported catalyst.

[0030] The active component loading in the activated carbon-supported catalyst is 17.4 wt%. Note: Calculate 2.1 / (2.1+10)=17.4%.

[0031] (2) 1 L of the activated carbon-supported catalyst obtained in step (1) was loaded into a tubular fixed-bed reactor. The reactor specifications were Φ38 mm × 4 mm × 2000 mm, the inner diameter was 38-2×4=30 mm, the catalyst loading amount was 1 L, and the catalyst loading height was calculated to be 1.41 m.

[0032] (3) Hydrogen chloride preheated to 180°C and vaporized n-butanol at 180°C are introduced into a fixed bed reactor. The reaction temperature is 180°C, the reaction pressure is 0.1 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.3:1, and the volumetric space velocity of n-butanol is 0.3 h -1 The catalytic reaction is carried out under the following conditions to obtain a mixed gas containing 1-chlorobutane.

[0033] (4) The obtained mixed gas containing 1-chlorobutane is passed into a condenser, cooled at 10°C and then subjected to gas-liquid separation to obtain a mixed liquid phase of 1-chlorobutane and hydrochloric acid and unreacted hydrogen chloride in the gas phase; the hydrogen chloride in the gas phase is absorbed by an alkaline solution; the mixed liquid phase is allowed to stand for stratification, and the upper organic phase is the product 1-chlorobutane.

[0034] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 93.8%, and the GC purity of the product was 99.624%.

[0035] The gas chromatogram of the product 1-chlorobutane obtained in this example is as follows Figure 1 As shown in FIG, the test conditions of the gas chromatogram are as follows: chromatographic column (7% cyanopropyl-7% phenyl-86% methylpolysiloxane capillary column, 30 m×0.32 mm×1.0 μm); initial column temperature 50°C, increased to 200°C at a heating rate of 10°C per minute, and maintained for 5 minutes; vaporization chamber temperature 200°C; detection chamber temperature 200°C; nitrogen carrier gas, flow rate 4 mL per minute; split ratio 30:1; injection volume 0.2 μL; FID detector.

[0036] Figure 1 The peak table of the shown spectrum is shown in Table 1.

[0037] Table 1 Peak table

[0038] pass Figure 1Combined with the peak table in Table 1, it can be seen that the method provided in Example 1 successfully synthesized 1-chlorobutane.

[0039] Example 2 The difference from Example 1 is that in step (3) of this embodiment, hydrogen chloride preheated to 200°C and vaporized n-butanol at 200°C are introduced into the fixed bed reactor, the reaction temperature is 200°C, the reaction pressure is 0.25 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.01:1, and the volumetric space velocity of n-butanol is 0.5h -1 .

[0040] Other details are the same as in Example 1.

[0041] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 92.6%, and the GC purity of the product was 99.505%.

[0042] Example 3 The difference from Example 1 is that in step (3) of this embodiment, hydrogen chloride preheated to 160°C and vaporized n-butanol at 160°C are introduced into the fixed bed reactor, the reaction temperature is 160°C, the reaction pressure is 0.05 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.15:1, and the volumetric space velocity of n-butanol is 0.1h -1 .

[0043] Other details are the same as in Example 1.

[0044] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 93.5%, and the GC purity of the product was 99.637%.

[0045] Example 4 The difference from Example 1 is that in step (3) of this embodiment, hydrogen chloride preheated to 190°C and vaporized n-butanol at 190°C are introduced into the fixed bed reactor, the reaction temperature is 190°C, the reaction pressure is 0.15 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.3:1, and the volumetric space velocity of n-butanol is 0.6h -1 .

[0046] Other details are the same as in Example 1.

[0047] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 92.2%, and the GC purity of the product was 99.440%.

[0048] Example 5 The difference from Example 1 is that the metal salts used in step (1) of this example are 2.0 kg zinc chloride, 0.1 kg ferric chloride, and 0.1 kg potassium chloride, wherein the mass ratio of zinc chloride:ferric chloride:potassium chloride is 1:0.05:0.05.

[0049] In step (3), hydrogen chloride preheated to 190°C and vaporized n-butanol at 190°C are introduced into a fixed bed reactor, the reaction temperature is 190°C, the reaction pressure is 0.15 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.2:1, and the volumetric space velocity of n-butanol is 0.8h -1 .

[0050] Other details are the same as in Example 1.

[0051] In this embodiment, the content of active components in the activated carbon catalyst is 18.0 wt %.

[0052] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 91.9% and the GC purity of the product was 99.511%.

[0053] Example 6 The difference from Example 1 is that the metal salts used in step (1) of this example are 1.5 kg zinc chloride, 0.3 kg ferric chloride, and 0.15 kg potassium chloride, wherein the mass ratio of zinc chloride:ferric chloride:potassium chloride is 1:0.2:0.1.

[0054] In step (3), hydrogen chloride preheated to 210°C and vaporized n-butanol at 210°C are introduced into a fixed bed reactor, the reaction temperature is 210°C, the reaction pressure is 0.2 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.5:1, and the volumetric space velocity of n-butanol is 1.3 h -1 .

[0055] Other details are the same as in Example 1.

[0056] In this embodiment, the content of active components in the activated carbon catalyst is 16.3 wt %.

[0057] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 92.0%, and the GC purity of the product was 99.530%.

[0058] Example 7 The difference from Example 1 is that the metal salts used in step (1) of this example are 1.4 kg zinc chloride, 0.25 kg ferric chloride, and 0.20 kg potassium chloride, wherein the mass ratio of zinc chloride:ferric chloride:potassium chloride is 1:0.18:0.14.

[0059] In step (3), hydrogen chloride preheated to 220°C and vaporized n-butanol at 220°C are introduced into a fixed bed reactor, the reaction temperature is 220°C, the reaction pressure is 0.3 MPa, the molar ratio of hydrogen chloride to n-butanol is 1.1:1, and the volumetric space velocity of n-butanol is 2.0 h -1 .

[0060] Other details are the same as in Example 1.

[0061] In this embodiment, the content of active components in the activated carbon catalyst is 15.6 wt %.

[0062] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 91.4% and the GC purity of the product was 99.614%.

[0063] Comparative Example 1 The difference from Example 1 is that the metal salts used in step (1) of this comparative example are 1.7 kg zinc chloride and 0.20 kg ferric chloride. That is, the active components of the catalyst in this comparative example are zinc chloride and ferric chloride.

[0064] Other details are the same as in Example 1.

[0065] In this comparative example, the loading amount of the active component in the activated carbon-supported catalyst was 16.0 wt %.

[0066] After 600 hours of continuous reaction, the yield of the product 1-chlorobutane was 92.8%, and the GC purity of the product was 99.578%.

[0067] After 650 hours of continuous reaction, the reactor bed was blocked due to severe carbon deposition.

[0068] Comparative Example 2 The difference from Example 1 is that the metal salts used in step (1) of this comparative example are 1.7 kg zinc chloride and 0.20 kg potassium chloride. That is, the active components of the catalyst in this comparative example are zinc chloride and potassium chloride.

[0069] Other details are the same as in Example 1.

[0070] In this comparative example, the loading amount of the active component in the activated carbon-supported catalyst was 16.0 wt %.

[0071] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 88.6% and the GC purity of the product was 99.052%.

[0072] Comparative Example 3 The difference from Example 1 is that the metal salts used in step (1) of this comparative example are 1.7 kg zinc chloride, 0.05 kg ferric chloride, and 0.05 kg potassium chloride.

[0073] That is, the mass ratio of zinc chloride: ferric chloride: potassium chloride is 1:0.03:0.03.

[0074] Other details are the same as in Example 1.

[0075] In this comparative example, the loading amount of the active component in the activated carbon-supported catalyst was 15.3 wt %.

[0076] After 1200 hours of continuous reaction, the yield of the product 1-chlorobutane was 89.1% and the GC purity of the product was 99.102%.

[0077] Comparative Example 4 The difference from Example 1 is that the metal salts used in step (1) of this comparative example are 0.85 kg zinc chloride, 0.1 kg ferric chloride, and 0.1 kg potassium chloride.

[0078] That is, the mass ratio of zinc chloride: ferric chloride: potassium chloride is 1:0.12:0.12.

[0079] Other details are the same as in Example 1.

[0080] In this comparative example, the loading amount of the active component in the activated carbon-supported catalyst is 9.5 wt %.

[0081] After 1200 hours of continuous reaction, the yield of product 1-chlorobutane was 75.7% and the GC purity of the product was 99.033%.

[0082] Comparative Example 5 The difference from Example 1 is that the metal salts used in step (1) of this comparative example are 1.7 kg of copper chloride and 0.2 kg of cobalt chloride. That is, the active components of the catalyst in this comparative example are copper chloride and cobalt chloride.

[0083] Other details are the same as in Example 1.

[0084] In this comparative example, the loading amount of the active component in the activated carbon-supported catalyst is 16 wt %.

[0085] After 100 hours of continuous reaction, the yield of the product 1-chlorobutane was 35.5%, and the GC purity of the product was 69.849%.

[0086] The yield and purity of the product 1-chlorobutane obtained after continuous reaction for corresponding lengths of time in each embodiment and comparative example are shown in Table 2.

[0087] Table 2 Yield and purity of product 1-chlorobutane

[0088] As can be seen from the data in Table 2, the method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction of the present invention can achieve long-term continuous production and maintain stable performance.

Claims

1. A method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction, characterized in that: The following steps are involved: (1) Loading the activated carbon-supported catalyst into a fixed bed reactor; The active components of the activated carbon-supported catalyst are composed of ZnCl2, FeCl3 and KCl; wherein the mass ratio of ZnCl2:FeCl3:KCl is 1:(0.05-0.2):(0.05-0.15); The active components are evenly loaded on the surface and pores of the carrier activated carbon, and the loading amount of the active components is 15%-20% of the total mass of the activated carbon-supported catalyst; (2) introducing preheated hydrogen chloride and vaporized n-butanol into a fixed bed reactor to contact the activated carbon-supported catalyst, wherein the molar ratio of hydrogen chloride to n-butanol is (1-2):1; When the reaction temperature is 150-250℃, the reaction pressure is 0.01-0.5MPa and the n-butanol space velocity is (0.1-2)h -1 The catalytic reaction is carried out under the conditions of , to obtain a mixed gas containing 1-chlorobutane, and the mixed gas is cooled and then subjected to gas-liquid separation to obtain 1-chlorobutane.

2. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 1, characterized in that: The activated carbon-supported catalyst in step (1) is cylindrical particles of Φ5 mm×(4-7) mm.

3. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 1, characterized in that: The activated carbon-supported catalyst in step (1) is prepared by the following steps: 1) Adding activated carbon to a nitric acid solution, stirring, filtering, washing with deionized water until neutral, and drying to obtain an activated carbon support; 2) Add ZnCl2, FeCl3 and KCl to deionized water and stir to obtain a mixed salt solution; 3) impregnating the activated carbon support obtained in step 1) into the mixed salt solution obtained in step 2), stirring and then allowing to stand, evaporating the solvent in a water bath, and then drying to obtain the activated carbon-supported catalyst.

4. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 3, characterized in that: In the preparation step 1) of the activated carbon-supported catalyst, each gram of activated carbon is added to 1.5-2.5 mL of nitric acid solution; wherein the concentration of the nitric acid solution is 1-12 mol / L.

5. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 4, characterized in that: In the preparation step 1) of the activated carbon-supported catalyst, each gram of activated carbon is added to 2 mL of nitric acid solution; wherein the concentration of the nitric acid solution is 4-10 mol / L.

6. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 3, characterized in that: In the preparation step 1) of the activated carbon-supported catalyst, the stirring speed is 50 rpm-100 rpm, the stirring time is 4 h-6 h, and the drying time is 4 h-6 h.

7. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 3, characterized in that: In step 3) of preparing the activated carbon-supported catalyst, the standing time is 1 h to 4 h, and the drying time is 4 h to 6 h.

8. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 1, characterized in that: In step (2), the preheating temperature of hydrogen chloride is 160-230°C, and the vaporization temperature of n-butanol is 160-230°C.

9. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 1, characterized in that: The specific operations of cooling and gas-liquid separation in step (2) are as follows: First, the obtained mixed gas containing 1-chlorobutane is cooled by heat exchange at a temperature of 10-25°C in a condenser; Then, the cooled mixed gas containing 1-chlorobutane is subjected to gas-liquid separation using a gas-liquid separator to obtain a mixed liquid phase and a gas phase; wherein the gas phase is treated with alkali solution and the unreacted hydrogen chloride contained therein is absorbed by the alkali solution; The obtained mixed liquid phase is allowed to stand for stratification, and the upper organic phase is the product 1-chlorobutane.

10. The method for synthesizing 1-chlorobutane by fixed-bed gas-solid catalytic reaction according to claim 1, characterized in that: The fixed bed reactor is a tubular fixed bed reactor with a specification of Φ38mm×4mm×2000mm.

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