Production method for co-production of chloroethylene carbonate and chloroethane

Abstract

The invention relates to the technical field of organic synthesis, in particular to a production method for co-production of chloroethylene carbonate and chloroethane, which comprises the following steps: chlorine and ethylene carbonate are used as raw materials to prepare a chloroethylene carbonate crude product under the illumination condition, and hydrogen chloride gas is produced as a byproduct; purifying the chloroethylene carbonate crude product to obtain a chloroethylene carbonate finished product; the method comprises the following steps: mixing hydrogen chloride gas with ethanol gas, and catalyzing under the action of a catalyst to generate crude chloroethane synthesis gas; and carrying out pressure swing adsorption separation on the chloroethane crude product synthesis gas, compressing the chloroethane gas to obtain a chloroethane liquid finished product, and recycling the surplus ethanol to the mixing process. According to the production method for co-production of chloroethylene carbonate and chloroethane, the byproduct hydrogen chloride in preparation of chloroethylene carbonate is used as a raw material for synthesis of chloroethane, so that resource utilization of waste gas is effectively realized, the treatment cost of tail gas is greatly reduced, and remarkable economic benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for producing chloroethylene carbonate and ethyl chloride. Background Art

[0002] Ethylene chlorocarbonate is an organic compound with the molecular formula C 3 H 3 C1O 3 , mainly used as raw materials for the production of fluoroethylene carbonate and vinylene carbonate, additives for lithium-ion battery electrolytes. Currently, chlorine gas is reacted with vinyl carbonate to synthesize chloroethylene carbonate in industry, and a large amount of hydrogen chloride is produced as a by-product in the process, which poses great environmental pressure and high processing costs. Therefore, how to directly convert the by-product hydrogen chloride for utilization, realize the closed-loop circulation of chlorine elements and zero emissions in the reaction process, meets the overall requirements of sustainable development of the industry.

[0003] Ethyl chloride, also known as ethyl chloride, is a colorless flammable gas with an ether-like odor. It is mainly used in the synthesis of dye intermediates, fragrance intermediates, ethyl cellulose, antibacterial agents and pesticides, and has a very wide range of uses. The preparation of ethyl chloride by the reaction of hydrogen chloride with ethanol is one of the ways to consume hydrogen chloride, and ethyl chloride is widely used in the synthesis of medicine, pesticides, dyes and chemical intermediates. The use of hydrogen chloride to prepare ethyl chloride not only solves the problem of hydrogen chloride utilization, but also obtains valuable chemical raw materials. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for producing ethylene chlorocarbonate and ethyl chloride. The hydrogen chloride produced as a by-product in the production of ethylene chlorocarbonate can be used as a raw material for the synthesis of ethyl chloride, which greatly reduces the treatment cost of tail gas and realizes the resource utilization of waste gas.

[0005] The present invention adopts the following technical solutions:

[0006] A method for producing ethylene chlorocarbonate and ethyl chloride, comprising the following steps:

[0007] (1) using chlorine and ethylene carbonate as raw materials to prepare a crude ethylene chlorocarbonate under light conditions, and producing hydrogen chloride gas as a by-product;

[0008] (2) purifying the crude ethylene chlorocarbonate product to obtain a finished ethylene chlorocarbonate product;

[0009] (3) mixing the hydrogen chloride gas and the ethanol gas to generate crude ethyl chloride synthesis gas under the action of a catalyst;

[0010] (4) The crude ethyl chloride synthesis gas after the reaction in step (3) is separated by pressure swing adsorption, and the ethyl chloride gas is compressed to obtain a liquid ethyl chloride product, and the surplus ethanol is recycled to the mixing process in step (3).

[0011] Furthermore, in step (1), the molar ratio of chlorine to ethylene carbonate is (1-1.2):1, the reaction temperature is 50-100° C., and the reaction time is 10-15 h.

[0012] Furthermore, the purification method in step (2) comprises subjecting the crude ethylene chlorocarbonate to degassing and vacuum distillation treatment;

[0013] The method of removing gas is to increase the temperature and introduce inert gas, the temperature is 100-140°C; and / or,

[0014] The vacuum degree of the reduced pressure distillation is 5 to 100 mmHg.

[0015] Furthermore, in step (3), the hydrogen chloride gas and the ethanol gas are mixed in a venturi mixer at a temperature of 80 to 110° C., the pressure of the ethanol gas is 0.1 to 0.3 MPa, and the pressure of the hydrogen chloride gas is 5 to 80 KPa.

[0016] Furthermore, in step (3), the crude ethyl chloride synthesis gas is synthesized in a synthesis tower, the catalyst is filled in the middle of the synthesis tower, the mixed gas of hydrogen chloride and ethanol enters from the bottom of the synthesis tower, and the crude ethyl chloride synthesis gas after the reaction is completed leaves from the top of the synthesis tower.

[0017] Furthermore, in step (3), the molar ratio of ethanol to hydrogen chloride in the synthesis tower is (1-1.2):1, the reaction temperature is 120-140° C., the reaction pressure is 0.2-0.4 MPa, and the reaction time is 1-2.5 h.

[0018] Furthermore, in step (3), the catalyst is FeCl 3 、ZnCl 2 、AlCl 3 One or more of the above; the catalyst is in the form of solid powder with a particle size of 10 to 50 nm; the amount of the catalyst used accounts for 10 to 20 wt% of the total weight of the material in the synthesis tower.

[0019] Furthermore, the pressure swing adsorption separation process in step (4) is carried out in a pressure swing adsorption device, which includes an adsorption tower A, an adsorption tower B, and a synthesis gas buffer tank, an ethyl chloride gas buffer tank, and an ethanol gas buffer tank respectively connected to the adsorption tower A and the adsorption tower B, and the connection is controlled by a programmable valve.

[0020] Further, the synthesis gas buffer tank is connected to one end of the adsorption tower A, and the ethyl chloride buffer tank is connected to the other end of the adsorption tower A. The crude ethyl chloride synthesis gas enters the adsorption tower A through the synthesis gas buffer tank for adsorption separation, and the unreacted ethanol gas is adsorbed by the molecular sieve in the adsorption tower A to obtain ethyl chloride gas, which enters the ethyl chloride gas buffer tank;

[0021] After the adsorption of adsorption tower A is completed, the connection between adsorption tower A and the synthesis gas buffer tank and the connection between adsorption tower A and the ethyl chloride gas buffer tank are disconnected successively, and adsorption tower A is connected to adsorption tower B for pressure equalization;

[0022] After the pressure equalization is completed, the connection between the adsorption tower A and the adsorption tower B is disconnected, and the adsorption tower A is connected to the ethanol gas buffer tank, and the ethanol gas enters the ethanol gas buffer tank;

[0023] After the release is completed, disconnect the adsorption tower A and the ethanol gas buffer tank, and connect the adsorption tower A and the adsorption tower B to increase the pressure evenly;

[0024] After the pressure increase is completed, the connection between adsorption tower A and adsorption tower B is disconnected, the synthesis gas buffer tank is connected to the adsorption tower A, and the final pressure of the adsorption tower A is increased using the crude ethyl chloride synthesis gas.

[0025] Furthermore, the pressure swing adsorption separation of step (4) is specifically as follows: the crude ethyl chloride synthesis gas with a pressure of 0.2 to 0.4 MPa after the reaction in step (3) enters the synthesis gas buffer tank, and the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1 after passing through the synthesis gas buffer tank, and the unreacted ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the molecular sieve in the adsorption tower A, and the unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 0.5 to 1.0 MPa to obtain the ethyl chloride liquid product;

[0026] After the adsorption of adsorption tower A is completed, the program-controlled valves VA-1 and VA-2 are closed in sequence to disconnect the connection between adsorption tower A and the synthesis gas buffer tank, and the connection between adsorption tower A and the ethyl chloride gas buffer tank; the program-controlled valve V-4 is opened to connect adsorption tower A and adsorption tower B, and the pressure equalization step is performed, and the pressure at the end of the pressure equalization is 0.1-0.2MPa;

[0027] After the pressure equalization is completed, close the program-controlled valve V-4, disconnect the adsorption tower A and the adsorption tower B, open the program-controlled valve VA-3, connect the adsorption tower A and the ethanol gas buffer tank for sequential discharge, and the pressure at the end of the sequential discharge is 0-0.01MPa. The ethanol gas in the sequential discharge step enters the ethanol gas buffer tank and is then reused in the Venturi mixer;

[0028] After the discharge is completed, close the program-controlled valve VA-3, disconnect the adsorption tower A and the ethanol gas buffer tank, open the program-controlled valve V-4, connect the adsorption tower A and the adsorption tower B, and evenly increase the pressure of the adsorption tower A;

[0029] After the pressure increase is completed, close the program-controlled valve V-4, disconnect the adsorption tower A and the adsorption tower B, open the program-controlled valve VA-1 to connect the synthesis gas buffer tank and the adsorption tower A, and use the crude ethyl chloride synthesis gas to perform the final pressure increase on the adsorption tower A; that is, one cycle is completed;

[0030] The adsorption tower A and the adsorption tower B alternately carry out the above-mentioned cycle process.

[0031] The method for producing ethylene chlorocarbonate and ethyl chloride of the present invention uses hydrogen chloride, a byproduct in the preparation of ethylene chlorocarbonate, as a raw material for synthesizing ethyl chloride, effectively realizes the resource utilization of waste gas, greatly reduces the treatment cost of tail gas, and has significant economic benefits.

[0032] The present invention purifies synthesis gas by means of pressure swing adsorption, and the obtained ethyl chloride has high purity. Meanwhile, the excess ethanol gas separated by adsorption can be reused as a raw material to prepare ethyl chloride, thereby reducing costs and increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 The present invention is a process flow chart of the method for producing ethylene chlorocarbonate and ethyl chloride;

[0035] Figure 2 The present invention is a pressure swing adsorption process flow chart of the method for producing ethylene chlorocarbonate and ethyl chloride. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0037] A method for producing ethylene chlorocarbonate and ethyl chloride, comprising the following steps:

[0038] (1) using chlorine and ethylene carbonate as raw materials to prepare a crude ethylene chlorocarbonate under light conditions, and producing hydrogen chloride gas as a by-product;

[0039] (2) purifying the crude ethylene chlorocarbonate product to obtain a finished ethylene chlorocarbonate product;

[0040] (3) mixing the hydrogen chloride gas and the ethanol gas to generate crude ethyl chloride synthesis gas under the action of a catalyst;

[0041] (4) The crude ethyl chloride synthesis gas after the reaction in step (3) is separated by pressure swing adsorption, and the ethyl chloride gas is compressed to obtain a liquid ethyl chloride product, and the excess ethanol is recycled to the mixing process in step (3).

[0042] The method for producing ethylene chlorocarbonate and ethyl chloride of the present invention uses hydrogen chloride, a byproduct in the preparation of ethylene chlorocarbonate, as a raw material for synthesizing ethyl chloride, effectively realizes the resource utilization of waste gas, greatly reduces the treatment cost of tail gas, and has significant economic benefits.

[0043] Specifically, in some embodiments of the present invention, the molar ratio of chlorine to ethylene carbonate in step (1) is (1-1.2):1, the reaction temperature is 50-100°C, and the reaction time is 10-15h. More specifically, the molar ratio of chlorine to ethylene carbonate in step (1) is 1:1, 1.02:1, 1.04:1, 1.05:1, 1.06:1, 1.08:1, 1.1:1, 1.12:1, 1.14:1, 1.15:1, 1.16:1, 1.18:1, 1.2:1 or any range between two values; preferably, the molar ratio of chlorine to ethylene carbonate in step (1) is 1.08:1-1.15:1. The reaction temperature is 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C or any range between them; preferably, the reaction temperature is 70-90°C. The reaction time is 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h or any range between them; preferably, the reaction time is 11-13h. By reacting a slightly excess of chlorine with ethylene carbonate, the reaction is ensured to be complete and the yield is improved, and the excess chlorine can be removed in the subsequent purification process.

[0044] Specifically, in some embodiments of the present invention, the purification method in step (2) comprises subjecting the crude ethylene chlorocarbonate to gas removal and vacuum distillation treatment;

[0045] As an embodiment of the present invention, the method of driving out the gas is to raise the temperature and introduce the inert gas, the temperature is 100-140°C; more specifically, the temperature is 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or any range between the two; preferably, the temperature is 110-130°C. Preferably, the inert gas is nitrogen. The chlorine and hydrogen chloride gas mixed in the chloroethylene carbonate are driven out by driving out the gas. Then, by vacuum distillation, a chloroethylene carbonate finished product with a purity of ≥99.0% is obtained. The vacuum degree of the reduced pressure distillation is 5 to 100 mmHg; more specifically, the vacuum degree is 5 mmHg, 10 mmHg, 15 mmHg, 20 mmHg, 25 mmHg, 30 mmHg, 35 mmHg, 40 mmHg, 45 mmHg, 50 mmHg, 60 mmHg, 70 mmHg, 80 mmHg, 90 mmHg, 100 mmHg or any range value therebetween; preferably, the vacuum degree is 10 to 50 mmHg.

[0046] Specifically, in some embodiments of the present invention, in step (3), the hydrogen chloride gas and the ethanol gas are mixed in a venturi mixer at a temperature of 80 to 110° C., the pressure of the ethanol gas is 0.1 to 0.3 MPa, and the pressure of the hydrogen chloride gas is 5 to 80 KPa.

[0047] More specifically, the temperature is 80° C., 84° C., 88° C., 90° C., 92° C., 95° C., 98° C., 100° C., 102° C., 105° C., 108° C., 110° C. or any range therebetween; preferably, the temperature is 90-100° C. The pressure of the ethanol gas is 0.1 MPa, 0.12 MPa, 0.15 MPa, 0.18 MPa, 0.2 MPa, 0.22 MPa, 0.25 MPa, 0.28 MPa, 0.3 MPa or any range therebetween; preferably, the pressure of the ethanol gas is 0.15-0.25 MPa. The pressure of the hydrogen chloride gas is 5 KPa, 10 KPa, 15 KPa, 20 KPa, 25 KPa, 30 KPa, 35 KPa, 40 KPa, 45 KPa, 50 KPa, 60 KPa, 65 KPa, 70 KPa, 75 KPa, 80 KPa or any range therebetween; preferably, the pressure of the hydrogen chloride gas is 20 to 50 KPa.

[0048] Specifically, in some embodiments of the present invention, in step (3), the crude ethyl chloride synthesis gas is synthesized in a synthesis tower, the catalyst is filled in the middle of the synthesis tower, the mixed gas of hydrogen chloride and ethanol enters from the bottom of the synthesis tower, and after the reaction is completed, the crude ethyl chloride synthesis gas leaves from the top of the synthesis tower.

[0049] Specifically, in some embodiments of the present invention, the molar ratio of ethanol to hydrogen chloride in the synthesis tower of step (3) is (1-1.2):1, the reaction temperature is 120-140° C., the reaction pressure is 0.2-0.4 MPa, and the reaction time is 1-2.5 h.

[0050] More specifically, the molar ratio of ethanol to hydrogen chloride in the synthesis tower of step (3) is 1:1, 1.02:1, 1.04:1, 1.05:1, 1.06:1, 1.08:1, 1.1:1, 1.12:1, 1.14:1, 1.15:1, 1.16:1, 1.18:1, 1.2:1 or any range between two values; preferably, the molar ratio of ethanol to hydrogen chloride in the synthesis tower of step (3) is 1.08:1 to 1.15:1. The reaction temperature is 120°C, 124°C, 125°C, 127°C, 130°C, 132°C, 135°C, 138°C, 140°C or any range between two values; preferably, the reaction temperature is 125 to 132°C. The reaction pressure is 0.2MPa, 0.22MPa, 0.25MPa, 0.28MPa, 0.3MPa, 0.32MPa, 0.35MPa, 0.38MPa, 0.4MPa or any range therebetween; preferably, the reaction pressure is 0.25-0.35MPa. The reaction time is 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h or any range therebetween; preferably, the reaction time is 1.5-2h.

[0051] Specifically, in some embodiments of the present invention, the catalyst in step (3) is FeCl 3 、ZnCl 2 、AlCl 3 One or more of; the catalyst is in the form of solid powder with a particle size of 10 to 50 nm; the amount of the catalyst accounts for 10 to 20 wt% of the total weight of the material in the synthesis tower. More specifically, the catalyst particle size is 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm or any range between the two; preferably, the catalyst particle size is 20 to 40 nm. The amount of the catalyst accounts for 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt% or any range between the two of the total weight of the material in the synthesis tower; preferably, the amount of the catalyst accounts for 12 to 16 wt% of the total weight of the material in the synthesis tower.

[0052] Specifically, in some embodiments of the present invention, Figure 1 As shown, the production method of ethylene chlorocarbonate co-producing ethyl chloride comprises the following steps:

[0053] (1) using chlorine and ethylene carbonate as raw materials to prepare a crude ethylene chlorocarbonate under light conditions, and producing hydrogen chloride gas as a by-product;

[0054] (2) subjecting the crude ethylene chlorocarbonate to degassing and vacuum distillation to obtain a finished ethylene chlorocarbonate;

[0055] (3) mixing the by-product hydrogen chloride gas and the ethanol gas in a venturi mixer to generate crude ethyl chloride synthesis gas under the action of a catalyst;

[0056] (4) The crude ethyl chloride synthesis gas after the reaction in step (3) is separated by pressure swing adsorption, and the ethyl chloride gas is compressed to obtain a liquid ethyl chloride product, and the excess ethanol is recycled to the mixing process in step (3).

[0057] More specifically, in some embodiments of the present invention, the method for producing ethylene chlorocarbonate and ethyl chloride comprises the following steps:

[0058] (1) pumping ethylene carbonate into a chlorination reaction kettle, stirring and heating to 50-100° C., turning on ultraviolet light, slowly introducing chlorine gas for 10-15 hours, and the molar ratio of chlorine gas to ethylene carbonate is (1-1.2):1, to obtain a crude ethylene chlorocarbonate and produce hydrogen chloride gas as a by-product;

[0059] (2) After the chlorination reaction is completed, the temperature in the chlorination reaction kettle is raised and an inert gas is introduced to drive out the gas, and then the material is transferred to the distillation tower kettle, and the vacuum pump is turned on to evacuate the temperature to 5-100 mmHg, and the fraction of 120-125° C. is collected to obtain a finished product of ethylene chlorocarbonate with a purity of ≥99.0%;

[0060] (3) mixing the by-product hydrogen chloride gas and ethanol gas in a venturi mixer at a temperature of 80 to 110° C., a pressure of the ethanol gas of 0.1 to 0.3 MPa, and a pressure of the hydrogen chloride gas of 5 to 80 KPa to obtain a mixed gas;

[0061] (4) A mixed gas of ethanol and hydrogen chloride is simultaneously introduced into the catalyst bed from the bottom of the synthesis tower. The molar ratio of ethanol to hydrogen chloride in the synthesis tower is (1-1.2):1. The reaction temperature is 120-140°C, the reaction pressure is 0.2-0.4 MPa, the reaction time is 1-2.5 h, and the catalyst is FeCl with a particle size of 10-50 nm. 3 、ZnCl 2 、AlCl 3 One or more of the solid powders to obtain crude ethyl chloride synthesis gas;

[0062] (5) The crude ethyl chloride synthesis gas is fed into a pressure swing adsorption device, and ethyl chloride gas with a purity of ≥99.5% is obtained after pressure swing adsorption separation. The ethyl chloride gas is compressed at 0.5-1.0 MPa to obtain a liquid ethyl chloride product, and excess ethanol is recycled to the venturi mixer in step (3).

[0063] Specifically, in some embodiments of the present invention, the pressure swing adsorption separation process in step (4) is carried out in a pressure swing adsorption device, which includes an adsorption tower A, an adsorption tower B, and a synthesis gas buffer tank, an ethyl chloride gas buffer tank, and an ethanol gas buffer tank respectively connected to the adsorption tower A and the adsorption tower B, and the connection is controlled by a programmable valve.

[0064] Specifically, in some embodiments of the present invention, a synthesis gas buffer tank is connected to one end of an adsorption tower A, and an ethyl chloride buffer tank is connected to the other end of the adsorption tower A. The crude ethyl chloride synthesis gas enters the adsorption tower A through the synthesis gas buffer tank for adsorption separation, and the unreacted ethanol gas is adsorbed by the molecular sieve in the adsorption tower A to obtain ethyl chloride gas, which enters the ethyl chloride gas buffer tank;

[0065] After the adsorption of adsorption tower A is completed, the connection between adsorption tower A and the synthesis gas buffer tank and the connection between adsorption tower A and the ethyl chloride gas buffer tank are disconnected successively, and adsorption tower A is connected to adsorption tower B for pressure equalization;

[0066] After the pressure equalization is completed, the connection between the adsorption tower A and the adsorption tower B is disconnected, and the adsorption tower A is connected to the ethanol gas buffer tank, and the ethanol gas enters the ethanol gas buffer tank;

[0067] After the release is completed, disconnect the adsorption tower A and the ethanol gas buffer tank, and connect the adsorption tower A and the adsorption tower B to increase the pressure evenly;

[0068] After the pressure increase is completed, the connection between adsorption tower A and adsorption tower B is disconnected, the synthesis gas buffer tank is connected to the adsorption tower A, and the final pressure of the adsorption tower A is increased using the crude ethyl chloride synthesis gas.

[0069] Specifically, in some embodiments of the present invention, the adsorption tower A and the adsorption tower B perform adsorption separation alternately.

[0070] Specifically, in some embodiments of the present invention, Figure 2As shown, the crude ethyl chloride synthesis gas with a pressure of 0.2 to 0.4 MPa after the reaction in step (3) enters the synthesis gas buffer tank. After passing through the synthesis gas buffer tank, the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1. The ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the carbon molecular sieve filled in the adsorption tower A. The unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 0.5 to 1.0 MPa to obtain the ethyl chloride liquid product. After a period of adsorption, close the program-controlled valves VA-1 and VA-2 in turn to complete the adsorption; open the program-controlled valve V-4 for the pressure equalization step, and the pressure at the end of the pressure equalization is 0.1-0.2MPa; after the pressure equalization is completed, close the program-controlled valve V-4, open the program-controlled valve VA-3 for the discharge, and the pressure at the end of the discharge is 0-0.01MPa. The ethanol gas in the discharge step enters the ethanol gas buffer tank and is then reused in the venturi mixer; after the discharge is completed, close the program-controlled valve VA-3, open the program-controlled valve V-4 to increase the pressure of the adsorption tower A; after the pressure equalization is completed, close the program-controlled valve V-4, open the program-controlled valve VA-1 to use the crude ethyl chloride synthesis gas to increase the final pressure of the adsorption tower A; that is, one cycle is completed. Adsorption tower A and adsorption tower B alternately carry out the above-mentioned cycle process to achieve continuous production of ethyl chloride.

[0071] By controlling the pressure of the crude ethyl chloride syngas entering the syngas buffer tank, the ethyl chloride and ethanol gas are prevented from being liquefied due to excessive pressure. Adsorption tower A and adsorption tower B alternately carry out the above cycle process, and the pressure of the main reaction adsorption tower is controlled by connecting adsorption tower A and adsorption tower B.

[0072] The invention purifies crude ethyl chloride synthesis gas by means of pressure swing adsorption, and the obtained ethyl chloride has high purity. Meanwhile, the excess ethanol gas separated by adsorption can be recycled as a raw material to prepare ethyl chloride, which plays a role in reducing costs and increasing efficiency.

[0073] The present invention will be further described below in conjunction with specific embodiments.

[0074] Example 1

[0075] A method for producing ethylene chlorocarbonate and ethyl chloride, comprising the following steps:

[0076] (1) pumping 20 kmol of ethylene carbonate into a chlorination reaction kettle, stirring and heating to 60° C., turning on ultraviolet light, slowly introducing 21 kmol of chlorine gas for 10 h, and obtaining a crude product of chloroethylene carbonate and producing hydrogen chloride gas as a by-product;

[0077] (2) After the chlorination reaction is completed, nitrogen is introduced into the chlorination reaction kettle and the temperature is raised to 120° C. to remove the gas, and then the material is transferred to the distillation tower kettle. The vacuum pump is turned on to evacuate the vacuum to 20 mmHg, and the 120-125° C. fraction is collected to obtain a 99.50% pure ethylene chlorocarbonate product;

[0078] (3) mixing the by-product hydrogen chloride gas and ethanol gas in a venturi mixer at a temperature of 80° C., a pressure of the ethanol gas of 0.2 MPa, and a pressure of the hydrogen chloride gas of 50 KPa to obtain a mixed gas of ethanol and hydrogen chloride;

[0079] (4) The ethanol and hydrogen chloride mixed gas is simultaneously introduced into the catalyst bed from the bottom of the synthesis tower. The molar ratio of ethanol to hydrogen chloride in the synthesis tower is 1.05:1, the reaction temperature is 130°C, the reaction pressure is 0.3 MPa, the reaction time is 2 h, and the catalyst is ZnCl with a particle size of 20 nm. 2 Solid powder, the amount of catalyst used accounts for 20wt% of the total weight of the materials in the synthesis tower to obtain ethyl chloride crude synthesis gas;

[0080] (5) The crude ethyl chloride synthesis gas with a pressure of 0.3 MPa enters the synthesis gas buffer tank. After passing through the synthesis gas buffer tank, the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1. The ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the carbon molecular sieve loaded in the adsorption tower A. The unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 0.8 MPa to obtain the ethyl chloride liquid product. The purity of ethyl chloride is 99.70%. After a period of adsorption, the program-controlled valves VA-1 and VA-2 are closed in sequence to complete the adsorption; the program-controlled valve V-4 is opened for the pressure equalization step, and the pressure at the end of the pressure equalization is 0.1MPa; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-3 is opened for the sequential release, and the pressure at the end of the sequential release is 0MPa. The ethanol gas in the sequential release step enters the ethanol gas buffer tank and is then reused in the venturi mixer; after the sequential release is completed, the program-controlled valve VA-3 is closed, and the program-controlled valve V-4 is opened to equalize the pressure of the adsorption tower A; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-1 is opened to use the crude ethyl chloride synthesis gas to finally increase the pressure of the adsorption tower A; that is, one cycle is completed. Adsorption tower A and adsorption tower B alternately carry out the above-mentioned cycle process to achieve continuous production of ethyl chloride.

[0081] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 99.50%, and the purity of the ethyl chloride gas obtained in step (5) is 99.70%.

[0082] Example 2

[0083] A method for producing ethylene chlorocarbonate and ethyl chloride, comprising the following steps:

[0084] (1) pumping 20 kmol of ethylene carbonate into a chlorination reaction kettle, stirring and heating to 100° C., turning on ultraviolet light, slowly introducing 20 kmol of chlorine gas for 10 hours, and obtaining a crude product of chloroethylene carbonate and producing hydrogen chloride gas as a by-product;

[0085] (2) After the chlorination reaction is completed, nitrogen is introduced into the chlorination reaction kettle and the temperature is raised to 140° C. to remove the gas, and then the material is transferred to the distillation tower kettle. The vacuum pump is turned on to evacuate the vacuum to 100 mmHg, and the fraction of 120-125° C. is collected to obtain a 99.30% pure ethylene chlorocarbonate product;

[0086] (3) mixing the by-product hydrogen chloride gas and ethanol gas in a venturi mixer at a temperature of 110° C., a pressure of the ethanol gas of 0.3 MPa, and a pressure of the hydrogen chloride gas of 80 KPa to obtain a mixed gas of ethanol and hydrogen chloride;

[0087] (4) A mixed gas of ethanol and hydrogen chloride is simultaneously introduced into the catalyst bed from the bottom of the synthesis tower. The molar ratio of ethanol to hydrogen chloride in the synthesis tower is 1.2:1, the reaction temperature is 120°C, the reaction pressure is 0.4 MPa, the reaction time is 2.5 h, and the catalyst is FeCl with a particle size of 10 nm. 3 Solid powder, the amount of catalyst used accounts for 10wt% of the total weight of the materials in the synthesis tower, and crude ethyl chloride synthesis gas is obtained;

[0088] (5) The crude ethyl chloride synthesis gas with a pressure of 0.2 MPa enters the synthesis gas buffer tank. After passing through the synthesis gas buffer tank, the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1. The ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the carbon molecular sieve loaded in the adsorption tower A. The unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 0.5 MPa to obtain the ethyl chloride liquid product. The purity of ethyl chloride is 99.60%. After a period of adsorption, the program-controlled valves VA-1 and VA-2 are closed in sequence to complete the adsorption; the program-controlled valve V-4 is opened for the pressure equalization step, and the pressure at the end of the pressure equalization is 0.15MPa; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-3 is opened for the sequential release, and the pressure at the end of the sequential release is 0.01MPa. The ethanol gas in the sequential release step enters the ethanol gas buffer tank and is then reused in the venturi mixer; after the sequential release is completed, the program-controlled valve VA-3 is closed, and the program-controlled valve V-4 is opened to equalize the pressure of the adsorption tower A; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-1 is opened to use the crude ethyl chloride synthesis gas to finally increase the pressure of the adsorption tower A; that is, one cycle is completed. Adsorption tower A and adsorption tower B alternately carry out the above-mentioned cycle process to achieve continuous production of ethyl chloride.

[0089] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 99.30%, and the purity of the ethyl chloride gas obtained in step (5) is 99.60%.

[0090] Example 3

[0091] A method for producing ethylene chlorocarbonate and ethyl chloride, comprising the following steps:

[0092] (1) pumping 20 kmol of ethylene carbonate into a chlorination reaction kettle, stirring and heating to 50° C., turning on ultraviolet light, slowly introducing 24 kmol of chlorine gas for 15 h, and obtaining a crude product of chloroethylene carbonate and producing hydrogen chloride gas as a by-product;

[0093] (2) After the chlorination reaction is completed, nitrogen is introduced into the chlorination reaction kettle and the temperature is raised to 100° C. to remove the gas, and then the material is transferred to the distillation tower kettle. The vacuum pump is turned on to evacuate the vacuum to 5 mmHg, and the fraction of 120 to 125° C. is collected to obtain a 99.00% pure ethylene chlorocarbonate product;

[0094] (3) mixing the by-product hydrogen chloride gas and ethanol gas in a venturi mixer at a temperature of 100° C., a pressure of the ethanol gas of 0.1 MPa, and a pressure of the hydrogen chloride gas of 5 KPa to obtain a mixed gas of ethanol and hydrogen chloride;

[0095] (4) A mixed gas of ethanol and hydrogen chloride is simultaneously introduced into the catalyst bed from the bottom of the synthesis tower. The molar ratio of ethanol to hydrogen chloride in the synthesis tower is 1:1, the reaction temperature is 140°C, the reaction pressure is 0.2 MPa, the reaction time is 1 h, and the catalyst is AlCl with a particle size of 50 nm. 3 Solid powder, the amount of catalyst used accounts for 10wt% of the total weight of the materials in the synthesis tower, and crude ethyl chloride synthesis gas is obtained;

[0096] (5) The crude ethyl chloride synthesis gas with a pressure of 0.4 MPa enters the synthesis gas buffer tank. After passing through the synthesis gas buffer tank, the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1. The ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the carbon molecular sieve loaded in the adsorption tower A. The unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 1.0 MPa to obtain the ethyl chloride liquid product. The purity of ethyl chloride is 99.85%. After a period of adsorption, the program-controlled valves VA-1 and VA-2 are closed in sequence to complete the adsorption; the program-controlled valve V-4 is opened for the pressure equalization step, and the pressure at the end of the pressure equalization is 0.2MPa; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-3 is opened for the sequential release, and the pressure at the end of the sequential release is 0.005MPa. The ethanol gas in the sequential release step enters the ethanol gas buffer tank and is then reused in the venturi mixer; after the sequential release is completed, the program-controlled valve VA-3 is closed, and the program-controlled valve V-4 is opened to equalize the pressure of the adsorption tower A; after the pressure equalization is completed, the program-controlled valve V-4 is closed, and the program-controlled valve VA-1 is opened to use the crude ethyl chloride synthesis gas to finally increase the pressure of the adsorption tower A; that is, one cycle is completed. Adsorption tower A and adsorption tower B alternately carry out the above-mentioned cycle process to achieve continuous production of ethyl chloride.

[0097] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 99.00%, and the purity of the ethyl chloride gas obtained in step (5) is 99.85%.

[0098] Example 4

[0099] This embodiment is basically the same as embodiment 1, except that after the chlorination reaction is completed in step (2), nitrogen is passed into the chlorination reaction kettle to remove the gas, but the temperature is not raised and the reaction is carried out at room temperature (25 degrees Celsius);

[0100] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 96.50%, and the purity of the ethyl chloride gas obtained in step (5) is 99.90%.

[0101] Example 5

[0102] This embodiment is basically the same as embodiment 1, except that after the chlorination reaction is completed in step (2), nitrogen is not introduced into the chlorination reaction kettle for degassing;

[0103] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 97.50%, and the purity of the ethyl chloride gas obtained in step (5) is 99.95%.

[0104] Example 6

[0105] This embodiment is basically the same as embodiment 1, except that after the chlorination reaction is completed in step (2), the chlorination reaction kettle is heated to 90° C. to expel gas;

[0106] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 98.70%, and the purity of the ethyl chloride gas obtained in step (5) is 99.90%.

[0107] Example 7

[0108] This embodiment is basically the same as embodiment 1, except that after the chlorination reaction in step (2) is completed, the chlorination reaction kettle is heated to 150° C. to drive out the gas;

[0109] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 98.80%, and the purity of the ethyl chloride gas obtained in step (5) is 99.20%.

[0110] Example 8

[0111] This embodiment is basically the same as embodiment 1, except that in step (5), the crude ethyl chloride synthesis gas with a pressure of 0.15 MPa is introduced into the synthesis gas buffer tank;

[0112] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 99.50%, and the purity of the ethyl chloride gas obtained in step (5) is 99.30%.

[0113] Example 9

[0114] This embodiment is basically the same as embodiment 1, except that in step (5), the crude ethyl chloride synthesis gas with a pressure of 0.45 MPa is introduced into the synthesis gas buffer tank;

[0115] In this embodiment, the purity of the ethylene chlorocarbonate product obtained in step (2) is 99.50%, and the purity of the ethyl chloride gas obtained in step (5) is 99.20%.

[0116] Comparative Example 1

[0117] This comparative example is basically the same as Example 1, except that steps (4) and (5) are omitted, and the mixed gas is directly sprayed with dilute hydrochloric acid, and then distilled and separated to obtain the ethyl chloride gas product.

[0118] The purity of the ethylene chlorocarbonate product obtained in step (2) of this comparative example is 99.50%, and the purity of the ethyl chloride gas finally obtained is 96.30%.

[0119] It can be seen from the test results of Examples 1-9 and Comparative Example 1 that the method for producing ethylene chlorocarbonate and ethyl chloride of the present invention can produce ethylene chlorocarbonate with a purity greater than 96.0% and ethyl chloride with a purity greater than 99.0%, and the excess ethanol gas can be recycled and reused, thereby reducing costs and achieving high economic benefits. As can be seen from the test results of Example 1 and Examples 4-7, part of the impurity gas is removed through the gas-dripping process to improve the purity of ethylene chlorocarbonate; if the gas-dripping temperature is too low, the solubility of chlorine is large and most of the chlorine cannot be driven out; if the gas-dripping temperature is too high, the gas-dripping process will increase the generation of diethylene chlorocarbonate; the gas-dripping effect of only nitrogen or only heating is not good, and the purity of the ethylene chlorocarbonate finished product is low; therefore, when the gas-dripping temperature of nitrogen is too high or too low, the purity of the ethylene chlorocarbonate finished product will decrease, and ventilation and controlling the gas-dripping temperature are one of the keys to industrial co-production, which can take into account the yield and purity of ethylene chlorocarbonate and ethyl chloride at the same time; as can be seen from the test results of Example 1 and Examples 8-9, when the initial pressure is too high in the pressure swing adsorption process, the pressure swing adsorption cannot play the role of selective separation; when the initial pressure is too low in the pressure swing adsorption process, the ethanol molecules cannot be completely adsorbed by the carbon molecular sieve loaded in the adsorption tower A; therefore, when the initial pressure is too high or too low, the purity of ethyl chloride gas will decrease. It can be seen from the test results of Example 1 and Comparative Example 1 that the present invention can effectively improve the purity of ethyl chloride by co-producing ethyl chloride through pressure swing adsorption, and can realize the reuse of ethanol, which is economical and efficient.

[0120] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for producing ethylene chlorocarbonate and ethyl chloride, characterized in that: The following steps are involved: (1) using chlorine and ethylene carbonate as raw materials to prepare a crude ethylene chlorocarbonate under light conditions, and producing hydrogen chloride gas as a by-product; (2) purifying the crude ethylene chlorocarbonate product to obtain a finished ethylene chlorocarbonate product; (3) mixing the hydrogen chloride gas and the ethanol gas to generate crude ethyl chloride synthesis gas under the action of a catalyst; (4) The crude ethyl chloride synthesis gas after the reaction in step (3) is separated by pressure swing adsorption, and the ethyl chloride gas is compressed to obtain a liquid ethyl chloride product, and the excess ethanol is recycled to the mixing process in step (3).

2. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 1, characterized in that: In step (1), the molar ratio of chlorine gas to ethylene carbonate is (1-1.2):1, the reaction temperature is 50-100° C., and the reaction time is 10-15 hours.

3. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 1, characterized in that: The purification method in step (2) comprises subjecting the crude ethylene chlorocarbonate to gas removal and vacuum distillation treatment; The method of removing the gas is to increase the temperature and introduce inert gas at a temperature of 100 to 140° C.; and / or, The vacuum degree of the reduced pressure distillation is 5 to 100 mmHg.

4. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 1, characterized in that: In step (3), the hydrogen chloride gas and the ethanol gas are mixed in a venturi mixer at a temperature of 80 to 110° C., the pressure of the ethanol gas is 0.1 to 0.3 MPa, and the pressure of the hydrogen chloride gas is 5 to 80 KPa.

5. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 1, characterized in that: In step (3), the crude ethyl chloride synthesis gas is synthesized in a synthesis tower, the catalyst is filled in the middle of the synthesis tower, the mixed gas of hydrogen chloride and ethanol enters from the bottom of the synthesis tower, and after the reaction is completed, the crude ethyl chloride synthesis gas leaves from the top of the synthesis tower.

6. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 5, characterized in that: In step (3), the molar ratio of ethanol to hydrogen chloride in the synthesis tower is (1-1.2):1, the reaction temperature is 120-140° C., the reaction pressure is 0.2-0.4 MPa, and the reaction time is 1-2.5 h.

7. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 5, characterized in that: The catalyst in step (3) is one or more of FeCl3, ZnCl2, and AlCl3; the catalyst is in the form of solid powder with a particle size of 10 to 50 nm; the amount of the catalyst used accounts for 10 to 20 wt% of the total weight of the material in the synthesis tower.

8. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 1, characterized in that: The pressure swing adsorption separation process in step (4) is carried out in a pressure swing adsorption device, which includes an adsorption tower A, an adsorption tower B, and a synthesis gas buffer tank, an ethyl chloride gas buffer tank and an ethanol gas buffer tank respectively connected to the adsorption tower A and the adsorption tower B, and the connection is controlled by a programmable valve.

9. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 8, characterized in that: Connecting a synthesis gas buffer tank to one end of an adsorption tower A, and connecting an ethyl chloride buffer tank to the other end of the adsorption tower A, the crude ethyl chloride synthesis gas passes through the synthesis gas buffer tank and enters the adsorption tower A for adsorption separation, and the unreacted ethanol gas is adsorbed by the molecular sieve in the adsorption tower A to obtain ethyl chloride gas, and the ethyl chloride gas enters the ethyl chloride gas buffer tank; After the adsorption of adsorption tower A is completed, the connection between adsorption tower A and the synthesis gas buffer tank and the connection between adsorption tower A and the ethyl chloride gas buffer tank are disconnected successively, and adsorption tower A is connected to adsorption tower B for pressure equalization; After the pressure equalization is completed, the connection between the adsorption tower A and the adsorption tower B is disconnected, and the adsorption tower A is connected to the ethanol gas buffer tank, and the ethanol gas enters the ethanol gas buffer tank; After the release is completed, disconnect the adsorption tower A and the ethanol gas buffer tank, and connect the adsorption tower A and the adsorption tower B to increase the pressure evenly; After the pressure increase is completed, the connection between adsorption tower A and adsorption tower B is disconnected, the synthesis gas buffer tank is connected to the adsorption tower A, and the final pressure of the adsorption tower A is increased using the crude ethyl chloride synthesis gas.

10. The method for producing ethylene chlorocarbonate and ethyl chloride according to claim 9, characterized in that: The pressure swing adsorption separation of step (4) is specifically as follows: the crude ethyl chloride synthesis gas with a pressure of 0.2-0.4 MPa after the reaction in step (3) enters the synthesis gas buffer tank, and the crude ethyl chloride synthesis gas enters the adsorption tower A from top to bottom through the program-controlled valve VA-1 after passing through the synthesis gas buffer tank, and the unreacted ethanol molecules in the crude ethyl chloride synthesis gas are adsorbed by the molecular sieve in the adsorption tower A, and the unadsorbed ethyl chloride gas enters the ethyl chloride gas buffer tank from the lower end of the adsorption tower A through the program-controlled valve VA-2 and the pipeline, and then enters the compression process to be compressed at 0.5-1.0 MPa to obtain the ethyl chloride liquid product; After the adsorption of adsorption tower A is completed, the program-controlled valves VA-1 and VA-2 are closed in sequence to disconnect the connection between adsorption tower A and the synthesis gas buffer tank, and the connection between adsorption tower A and the ethyl chloride gas buffer tank; the program-controlled valve V-4 is opened to connect adsorption tower A and adsorption tower B, and the pressure equalization step is performed, and the pressure at the end of the pressure equalization is 0.1-0.2MPa; After the pressure equalization is completed, close the program-controlled valve V-4, disconnect the adsorption tower A and the adsorption tower B, open the program-controlled valve VA-3, connect the adsorption tower A and the ethanol gas buffer tank for sequential discharge, and the pressure at the end of the sequential discharge is 0-0.01MPa. The ethanol gas in the sequential discharge step enters the ethanol gas buffer tank and is then reused in the Venturi mixer; After the discharge is completed, close the program-controlled valve VA-3, disconnect the adsorption tower A and the ethanol gas buffer tank, open the program-controlled valve V-4, connect the adsorption tower A and the adsorption tower B, and evenly increase the pressure of the adsorption tower A; After the pressure increase is completed, close the program-controlled valve V-4, disconnect the adsorption tower A and the adsorption tower B, open the program-controlled valve VA-1 to connect the synthesis gas buffer tank and the adsorption tower A, and use the crude ethyl chloride synthesis gas to perform the final pressure increase on the adsorption tower A; that is, one cycle is completed; The adsorption tower A and the adsorption tower B alternately carry out the above-mentioned cycle process.

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