Method for preparing acetaldehyde and dichloroethane

Abstract

The invention discloses a method for preparing acetaldehyde and 1, 2-dichloroethane, and relates to the technical field of chemical engineering. According to the preparation method disclosed by the invention, ethylene glycol and hydrogen chloride are taken as reaction raw materials, a multi-stage serial kettle type distillation reactor is utilized, and acetaldehyde and 1, 2-dichloroethane are continuously prepared through reaction under certain pressure and certain temperature under the action of a catalyst. The method is characterized in that the generated acetaldehyde and dichloroethane with low boiling points are continuously brought out by utilizing the distillation reactors, and a plurality of kettle type distillation reactors are connected in series to strengthen the reaction effect, so that the method is a novel method for efficiently producing acetaldehyde and 1, 2-dichloroethane.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for preparing acetaldehyde and ethylene dichloride. Background Art

[0002] Acetaldehyde has important industrial application value and can be used to manufacture polyacetaldehyde, acetic acid, synthetic rubber, etc. In traditional industries, acetaldehyde is mainly prepared by ethylene oxidation. Ethylene dichloride is an important raw material for preparing vinyl chloride monomer, which is mainly used to produce polyvinyl chloride. At present, ethylene dichloride is mainly prepared by ethylene chlorination. However, my country's petroleum resources are scarce, the price of industrial ethylene is also rising, and combined with my country's energy status of rich coal and less oil, it is necessary to make full use of coal resources and develop a method for producing acetaldehyde and ethylene dichloride based on coal as raw materials, which has important application prospects.

[0003] With the vigorous development of coal-to-ethylene glycol, the output of ethylene glycol is increasing, and the price of ethylene glycol products is also decreasing. Therefore, it is of practical significance to develop downstream products of ethylene glycol and promote the research on the conversion of ethylene glycol into higher value-added chemicals. Ethylene glycol can undergo a dehydration reaction under the action of a strong acid catalyst to produce acetaldehyde, and ethylene glycol can undergo a chlorination reaction with hydrogen chloride under the action of a catalyst to produce 2-chloroethanol and dichloroethane. Therefore, the technology of directly converting ethylene glycol and hydrogen chloride into acetaldehyde and dichloroethane with high selectivity is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing acetaldehyde and 1,2-dichloroethane using a multi-stage kettle series distillation reaction process to address the deficiencies in the current technology; the method can continuously and efficiently catalyze the conversion of ethylene glycol to obtain acetaldehyde and 1,2-dichloroethane in higher yields.

[0005] In one aspect, the present invention provides a method for preparing acetaldehyde and ethylene dichloride, comprising the following steps: reacting a raw material comprising ethylene glycol and hydrogen chloride with a catalyst in a multi-stage tank-type series distillation reactor to produce acetaldehyde and 1,2-dichloroethane;

[0006] Wherein, the feed molar ratio of the ethylene glycol to the hydrogen chloride is 1:0.1-4;

[0007] The reaction pressure is 0.1-1 MPa, and the reaction temperature is 150-350°C.

[0008] Optionally, the molar ratio of the ethylene glycol and hydrogen chloride feeds is selected from any value among 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 and 10.0 or any range value therebetween.

[0009] Optionally, the pressure is selected from any value among 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa and 1 MPa, or any range between two values.

[0010] Optionally, the temperature is selected from any value among 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃ and 350℃, or any range therebetween.

[0011] Optionally, the multi-stage kettle-type series distillation reactor is composed of 2 to 20 kettle-type distillation reactors connected in series.

[0012] Optionally, the number of kettle distillation reactors in the multi-stage kettle series distillation reactor is selected from any value of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or a range between any two of them.

[0013] Optionally, the series connection is that the discharge port of the previous stage kettle distillation reactor is connected with the feed port of the next stage kettle distillation reactor.

[0014] Optionally, each of the multi-stage series-connected kettle distillation reactors is provided with a catalyst.

[0015] Optionally, the raw material containing ethylene glycol and hydrogen chloride enters from the feed port of the first end tank distillation reactor in the multi-stage tank distillation reactor, generates acetaldehyde and 1,2-dichloroethane after multi-stage catalytic reaction, and the acetaldehyde and 1,2-dichloroethane are output from the discharge port of the last end tank distillation reactor in the multi-stage tank distillation reactor.

[0016] That is, the multi-stage kettle distillation reactor comprises a plurality of kettle distillation reactors connected in series, and the series connection is that the discharge port of the previous kettle distillation reactor is connected with the feed port of the next kettle distillation reactor; each kettle distillation reactor is provided with a catalyst; raw materials containing ethylene glycol and hydrogen chloride are introduced into the feed port of the first kettle distillation reactor of the multi-stage kettle distillation reactor; and the products acetaldehyde and 1,2-dichloroethane are output from the discharge port of the last kettle distillation reactor of the multi-stage kettle distillation reactor.

[0017] Optionally, the kettle distillation reactor includes a reaction chamber, a reflux controller is provided at the upper part of the reaction chamber, and a gas distributor is provided at the lower part of the reaction chamber; a discharge port is provided at the top of the reaction chamber, and a feed port is provided at the bottom of the reaction chamber.

[0018] Optionally, the material of the reaction chamber, the reflux controller or the gas distributor is selected from one of Hastelloy, Monel, graphite lining, glass lining, enamel and polytetrafluoroethylene lining.

[0019] Optionally, the catalyst is a pure liquid phase catalyst system or a liquid-solid phase mixture catalyst system.

[0020] Optionally, the pure liquid phase catalyst system includes at least one of imidazole hydrochloride, pyridine hydrochloride, piperidine hydrochloride, triethylamine hydrochloride, trioctylamine hydrochloride and tetraalkylammonium chloride.

[0021] Optionally, the imidazole hydrochloride is selected from at least one of 1-methylimidazole hydrochloride, 1-ethyl-3-methylimidazole hydrochloride, 1-butyl-3-methylimidazole hydrochloride and 1-hexyl-3-methylimidazole chloride.

[0022] Optionally, the pyridine hydrochloride is selected from at least one of 2-chloromethylpyridine hydrochloride, 1-butylpyridine hydrochloride and 1-butyl-4-methylpyridinium chloride hydrochloride.

[0023] Optionally, the tetraalkylammonium chloride is selected from at least one of tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride and tetrabutylammonium chloride.

[0024] Optionally, the liquid-solid mixture catalyst system consists of a liquid catalyst system and a solid porous material.

[0025] Optionally, the solid porous material is selected from one of carbon molecular sieve, mesoporous carbon, activated carbon, porous silica, porous silicon carbide and silicon-aluminum molecular sieve.

[0026] Optionally, the molecular sieve uses all-silicon molecular sieve or high-silicon molecular sieve;

[0027] Preferably, the high silicon molecular sieve is a molecular sieve with SiO2 / Al2O3≥100;

[0028] Optionally, the molecular sieve is at least one selected from MCM-41, SBA-15, silicalite-1, ZSM-5, Beta and mordenite.

[0029] Optionally, the time for the raw material containing ethylene glycol and hydrogen chloride to contact and react with the catalyst in the multi-stage series-tank distillation reactor is 0.01 to 5 hours.

[0030] The above reaction time of the present invention is the total reaction time.

[0031] Optionally, the contact reaction time is independently selected from any value among 0.01h, 0.05h, 0.1h, 0.2h, 0.5h, 1.0h, 1.2h, 1.5h, 2.0h, 2.5h, 3.0h, 3.5h, 4.0h, 4.5h, 5.0h, or any range between two thereof.

[0032] Compared with the prior art, the beneficial effects of this application include:

[0033] 1) The method for preparing ethylene dichloride by the multi-stage kettle series distillation reaction process provided by the present invention can continuously and efficiently catalyze the conversion of ethylene glycol, and the yields of acetaldehyde and 1,2-dichloroethane are very high.

[0034] 2) The method for preparing acetaldehyde and 1,2-dichloroethane provided in the present invention has great economic benefits, not only developing downstream products of ethylene glycol, but also being closely connected with the vinyl chloride industry.

[0035] 3) The method for preparing acetaldehyde and ethylene dichloride by a multi-stage tank series distillation reaction process of the present invention has a small capacity of a single tank in the multi-stage tank series process under the condition of the same total reaction volume, and is easier to control in terms of mass transfer and heat transfer, and the reaction control is more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of a multi-stage kettle-type series distillation reactor provided in an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of a kettle distillation reactor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present application is further described below in conjunction with specific embodiments. The following are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application discloses the following preferred embodiments, they are not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the above disclosed technical content to make some changes or modifications are equivalent to equivalent implementation cases and are within the scope of the technical solution.

[0039] Unless otherwise specified, the raw materials in the examples of the present application were purchased from commercial sources and used directly without any special treatment.

[0040] The analysis method in the embodiment of the present invention is as follows:

[0041] The conversion rate of ethylene glycol in the embodiment of the present invention is calculated by the following method:

[0042] The gas chromatographic peak area is obtained by configuring the ethylene glycol content in the standard solution, and the peak area is used as the horizontal coordinate and the concentration of ethylene glycol is used as the vertical coordinate to obtain a standard curve; further, the concentration of ethylene glycol in the reaction solution after the reaction can be calculated, and the conversion rate of ethylene glycol can be calculated through the concentration.

[0043] In the embodiment of the present invention, the yield of 1,2-dichloroethane is calculated by the following method:

[0044] The gas chromatographic peak area is obtained by configuring the 1,2-dichloroethane content in the standard solution, and the peak area is used as the horizontal coordinate and the concentration of 1,2-dichloroethane is used as the vertical coordinate to obtain a standard curve; further, the concentration of 1,2-dichloroethane in the reaction solution after the reaction can be calculated, and the yield of 1,2-dichloroethane can be calculated based on the concentration.

[0045] In the embodiment of the present invention, the yield of acetaldehyde is calculated by the following method:

[0046] The gas chromatographic peak area is obtained by configuring the acetaldehyde content in the standard solution, and the peak area is used as the horizontal coordinate and the concentration of acetaldehyde is used as the vertical coordinate to obtain a standard curve; further, the concentration of acetaldehyde in the reaction solution after the reaction can be calculated, and the acetaldehyde yield can be calculated based on the concentration.

[0047] Conversion rate of ethylene glycol (%) = (mass of ethylene glycol after reaction / initial mass of ethylene glycol)*100%.

[0048] Yield of 1,2-dichloroethane (%) = (mass of 1,2-dichloroethane obtained by reaction * 62.06 / 98.96 * initial mass of ethylene glycol) * 100%.

[0049] The yield of acetaldehyde (%) = (the mass of acetaldehyde obtained by the reaction * 62.06 / 44.05 * the initial mass of ethylene glycol) * 100%.

[0050] The gas chromatograph model is Agilent 7890.

[0051] Reaction contact time = catalyst mass / mass flow rate of ethylene glycol

[0052] Comparative Example

[0053] 30g of pyridine hydrochloride catalyst was placed in a single tank distillation reactor, the reactor was heated to 220°C, hydrogen chloride was charged to make the reactor pressure reach 0.3Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas were continuously introduced into the inlet end of the single tank distillation reactor according to a molar ratio of 1:2, the mass flow rate of ethylene glycol was 60g / h, the reaction contact time with the catalyst was 0.5 hours, and the reaction products acetaldehyde and 1,2-dichloroethane were continuously discharged from the outlet end of the single tank distillation reactor in gaseous form. Gas chromatography analysis and calculation showed that the ethylene glycol conversion rate was 72%, the acetaldehyde yield was 33%, and the 1,2-dichloroethane yield was 44%.

[0054] Example 1

[0055] The structure of multi-stage series distillation reactor is as follows: Figure 1 and 2 As shown, it includes multiple kettle distillation reactors connected in series, and the series connection is that the discharge port of the previous kettle distillation reactor is connected to the feed port of the next kettle distillation reactor; each kettle distillation reactor is provided with a catalyst. The kettle distillation reactor includes a reaction chamber, the upper part of the reaction chamber is provided with a reflux controller, and the lower part of the reaction chamber is provided with a gas distributor; the top of the reaction chamber is provided with a discharge port, and the bottom of the reaction chamber is provided with a feed port. Ethylene glycol and hydrogen chloride raw gas are introduced into the feed port of the first kettle distillation reactor of the multi-stage kettle distillation reactor in series; the reaction products acetaldehyde and 1,2-dichloroethane are output from the discharge port of the last kettle distillation reactor of the multi-stage kettle distillation reactor in series.

[0056] 150g of pyridine hydrochloride catalyst is evenly placed in a five-stage series-connected tank distillation reactor, the reactor is heated to 220°C, hydrogen chloride is charged to make the reactor pressure reach 0.3Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor of the five series-connected tank distillation reactors according to a molar ratio of 1:2, the mass flow rate of ethylene glycol is 300g / h, the reaction contact time with the catalyst is 0.5 hours, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor of the five series-connected tank distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 99%, the acetaldehyde yield is 29%, and the 1,2-dichloroethane yield is 70%.

[0057] Example 2

[0058] 600g of triethylamine hydrochloride catalyst is evenly placed in 20-stage series-connected kettle distillation reactors, the reactors are heated to 150 degrees, hydrogen chloride is charged to make the reactor pressure reach 1Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor in the series-connected kettle distillation reactors according to a molar ratio of 1:4, the mass flow rate of ethylene glycol is 120g / h, the reaction contact time with the catalyst is 5 hours, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor in the series-connected kettle distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 15%, and the 1,2-dichloroethane yield is 85%.

[0059] Example 3

[0060] 120g of piperidine hydrochloride and 120g of activated carbon catalyst are evenly placed in an eight-stage series-connected kettle distillation reactor, the reactor is heated to 350°C, hydrogen chloride is charged to make the reactor pressure reach 0.5Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor in the series-connected kettle distillation reactors according to a molar ratio of 1:0.1, the mass flow rate of ethylene glycol is 24Kg / h, the reaction contact time with the catalyst is 0.01 hour, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor in the series-connected kettle distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 90%, the acetaldehyde yield is 63%, and the 1,2-dichloroethane yield is 25%.

[0061] Example 4

[0062] 300g of 1-butyl-3-methylimidazole hydrochloride and 150g of a strong acidic cation exchange resin catalyst are evenly placed in a fifteen-stage series-connected tank distillation reactor, the reactor is heated to 200°C, hydrogen chloride is charged to make the reactor pressure reach 0.1Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor in the series-connected tank distillation reactors according to a molar ratio of 1:1, the mass flow rate of ethylene glycol is 450g / h, the reaction contact time with the catalyst is 1 hour, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor in the series-connected tank distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 45%, and the 1,2-dichloroethane yield is 55%.

[0063] Example 5

[0064] 55g of trioctylamine hydrochloride and 5g of ZSM-5 molecular sieve catalyst are evenly placed in a two-stage tank distillation reactor in series, the reactor is heated to 300°C, hydrogen chloride is charged to make the reactor pressure reach 0.7Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor in the series of tank distillation reactors in a molar ratio of 1:0.5, the mass flow rate of ethylene glycol is 600g / h, the reaction contact time with the catalyst is 0.1 hour, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor in the series of tank distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 94%, the acetaldehyde yield is 53%, and the 1,2-dichloroethane yield is 38%.

[0065] Example 6

[0066] 250g of 1-ethyl-3-methylimidazole hydrochloride and 50g of porous silica catalyst are evenly placed in a ten-stage series-connected kettle distillation reactor, the reactor is heated to 250°C, hydrogen chloride is charged to make the reactor pressure reach 0.2Mpa, the reaction raw materials ethylene glycol and hydrogen chloride gas are continuously introduced into the inlet end of the first reactor in the series-connected kettle distillation reactors according to a molar ratio of 1:3, the mass flow rate of ethylene glycol is 150g / h, the reaction contact time with the catalyst is 2 hours, and the reaction products acetaldehyde and 1,2-dichloroethane are continuously discharged in gaseous form from the outlet end of the last reactor in the series-connected kettle distillation reactors. Gas chromatography analysis and calculation show that the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 23%, and the 1,2-dichloroethane yield is 77%.

[0067] It can be seen from the reaction results of Example 1 and the comparative example that:

[0068] Under the same reaction conditions, the comparative example uses a single kettle distillation reactor to obtain an ethylene glycol conversion rate of 72%, an acetaldehyde yield of 33%, and a 1,2-dichloroethane yield of 44%; Example 1 of the present invention uses a five-stage kettle series distillation reactor to obtain an ethylene glycol conversion rate of 99%, an acetaldehyde yield of 29%, and a 1,2-dichloroethane yield of 70%. Obviously, after using a multi-stage series distillation reactor, the ethylene glycol conversion rate of Example 1 of the present invention is increased from 72% to 99%, and the 1,2-dichloroethane yield is increased from 44% to 70%.

[0069] In Example 2 of the present invention, after 20 stages of series-connected distillation reactors are used, the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 15%, and the 1,2-dichloroethane yield is 85%.

[0070] In Example 3 of the present invention, after using 8-stage series distillation reactors, the ethylene glycol conversion rate is 90%, the acetaldehyde yield is 63%, and the 1,2-dichloroethane yield is 25%.

[0071] In Example 4 of the present invention, after 15 stages of series-connected distillation reactors are used, the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 45%, and the 1,2-dichloroethane yield is 55%.

[0072] In Example 5 of the present invention, after using two-stage series distillation reactors, the ethylene glycol conversion rate is 94%, the acetaldehyde yield is 53%, and the 1,2-dichloroethane yield is 38%.

[0073] In Example 6 of the present invention, after using 10 stages of series-connected distillation reactors, the ethylene glycol conversion rate is 100%, the acetaldehyde yield is 23%, and the 1,2-dichloroethane yield is 77%.

[0074] It can be seen from the above experiments that the present invention can improve the ethylene glycol conversion rate and product yield by using 2 to 20 stages of series distillation reactors compared with a single-stage distillation reactor.

[0075] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing acetaldehyde and ethylene dichloride, characterized in that: The following steps are involved: The raw materials including ethylene glycol and hydrogen chloride are contacted with a catalyst in a multi-stage tank series distillation reactor to react and generate acetaldehyde and 1,2-dichloroethane; Wherein, the feed molar ratio of the ethylene glycol to the hydrogen chloride is 1:0.1-4; The reaction pressure is 0.1-1Mpa, and the reaction temperature is 150-350°C.

2. A method for preparing acetaldehyde and ethylene dichloride according to claim 1, characterized in that: The multi-stage kettle-type series distillation reactor is composed of 2 to 20 kettle-type distillation reactors connected in series.

3. A method for preparing acetaldehyde and ethylene dichloride according to claim 2, characterized in that: The series connection is that the discharge port of the first-stage kettle distillation reactor is connected with the feed port of the second-stage kettle distillation reactor; Preferably, each of the multi-stage tank distillation reactors in series is provided with a catalyst; Preferably, the raw materials containing ethylene glycol and hydrogen chloride enter from the feed port of the head-end kettle distillation reactor in the multi-stage kettle distillation reactor, and generate acetaldehyde and 1,2-dichloroethane after multi-stage catalytic reaction, and the acetaldehyde and 1,2-dichloroethane are output from the discharge port of the terminal kettle distillation reactor in the multi-stage kettle distillation reactor.

4. A method for preparing acetaldehyde and ethylene dichloride according to claim 2, characterized in that: The kettle distillation reactor comprises a reaction chamber, a reflux controller is arranged at the upper part of the reaction chamber, a gas distributor is arranged at the lower part of the reaction chamber; a discharge port is arranged at the top of the reaction chamber, and a feed port is arranged at the bottom of the reaction chamber; Preferably, the material of the reaction chamber, the reflux controller or the gas distributor is selected from one of Hastelloy, Monel, graphite lining, glass lining, enamel and polytetrafluoroethylene lining.

5. A method for preparing acetaldehyde and ethylene dichloride according to claim 1, characterized in that: The catalyst is a pure liquid phase catalyst system or a liquid-solid phase mixture catalyst system.

6. A method for preparing acetaldehyde and ethylene dichloride according to claim 5, characterized in that: The pure liquid phase catalyst system comprises at least one of imidazole hydrochloride, pyridine hydrochloride, piperidine hydrochloride, triethylamine hydrochloride, trioctylamine hydrochloride and tetraalkylammonium chloride; Preferably, the imidazole hydrochloride is selected from at least one of 1-methylimidazole hydrochloride, 1-ethyl-3-methylimidazole hydrochloride, 1-butyl-3-methylimidazole hydrochloride and 1-hexyl-3-methylimidazole chloride; Preferably, the pyridine hydrochloride is selected from at least one of 2-chloromethylpyridine hydrochloride, 1-butylpyridine hydrochloride and 1-butyl-4-methylpyridinium chloride hydrochloride; Preferably, the tetraalkylammonium chloride is selected from at least one of tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride and tetrabutylammonium chloride.

7. A method for preparing acetaldehyde and ethylene dichloride according to claim 5, characterized in that: The liquid-solid phase mixture catalyst system consists of a liquid phase catalyst system and a solid porous material.

8. A method for preparing acetaldehyde and ethylene dichloride according to claim 7, characterized in that: The solid porous material is selected from one of carbon molecular sieve, mesoporous carbon, activated carbon, porous silica, porous silicon carbide and silicon-aluminum molecular sieve.

9. A method for preparing acetaldehyde and ethylene dichloride according to claim 8, characterized in that: The molecular sieve uses all-silicon molecular sieve or high-silicon molecular sieve; Preferably, the high silicon molecular sieve is a molecular sieve with SiO2 / Al2O3≥100; Preferably, the molecular sieve is at least one selected from MCM-41, SBA-15, silicalite-1, ZSM-5, Beta and mordenite.

10. A method for preparing acetaldehyde and ethylene dichloride according to claim 1, characterized in that: The time for the raw material containing ethylene glycol and hydrogen chloride to contact and react with the catalyst in the multi-stage tank-type series distillation reactor is 0.01 to 5 hours.

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