Glycol ether product production system and method

Abstract

The invention relates to a glycol ether product production system and method, and the method comprises the following steps: mixing ethylene oxide with nitrogen, and carrying out a glycol ether synthesis reaction with a preheated alcohol raw material in an alcohol ether reactor; carrying out gas-liquid separation on a reaction product in the alcohol ether reactor, and recovering a separated gas phase as first circulating gas; the separated liquid phase is subjected to dealcoholization and staged refining, glycol ether products of different grades are obtained, the gas phase formed through dealcoholization is recycled as second circulation gas, and the first circulation gas and the second circulation gas are fed into an alcohol ether reactor after being subjected to heat exchange with alcohol raw materials in a preheating heat exchanger. The method is easy to operate and stable in operation, has the advantages of small investment, rich product marks and low energy consumption, and can obtain good operation benefits.

Description

Technical Field

[0001] This invention relates to the field of ethylene glycol ether production technology, and in particular to a system and method for producing ethylene glycol ether products. Background Technology

[0002] Ethylene glycol ethers, such as ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether, are important members of the ethylene oxide (EO) industrial derivative system and typical representatives of diol ether compounds. Their hierarchical structural formula is CH3-(CH2)3-O-(CH2)2-OH. The molecular structure of this compound possesses both ether and hydroxyl bifunctional characteristics, giving it both hydrophilic and hydrophobic properties, thus exhibiting excellent solvent compatibility and forming homogeneous systems with polar solvents and non-polar organic compounds. This unique solubility has earned it the reputation of a "universal solvent" in the industrial field. In the surface treatment field, this compound, as a core component of efficient solvent systems, is widely used in the formulation of high-end furniture coating materials and environmentally friendly architectural coatings. In the detergent manufacturing field, its surface tension regulation properties significantly improve the substrate wetting performance and penetration efficiency of detergents, making it an important functional additive in liquid cleaning agents. In the transportation industry, based on its stable physicochemical properties, this substance has been established as a key raw material for the production of automotive hydraulic brake fluid.

[0003] The mainstream industrial synthesis process for ethylene glycol ethers is based on the ethoxylation reaction mechanism. This reaction is essentially a ring-opening addition process involving ethylene oxide and compounds containing active hydrogen (including but not limited to alcohols, phenols, carboxylic acids, and amines) under catalysis, with the active hydrogen compound acting as an initiator.

[0004] Taking the industrial production of ethylene glycol monobutyl ether as an example, it currently mainly relies on four typical process systems: batch reactor process, press spray process, bus circulation process, and tubular continuous process. Although the above processes have shown specific technological advantages in the industrialization process, they still face several common technical bottlenecks that need to be overcome:

[0005] (1) The contradiction between product selectivity and side reaction inhibition is prominent. Due to the cascading reaction characteristics of the ethoxylation reaction, the target product, ethylene glycol monobutyl ether, is prone to deep addition with excess ethylene oxide, forming byproducts such as ethylene glycol polybutyl ether. Existing processes lack effective means to control molecular weight distribution, resulting in generally low product selectivity;

[0006] (2) Limited application of catalysts in engineering. Although existing homogeneous catalytic systems (such as NaOH and KOH) have high catalytic activity, they suffer from problems such as equipment corrosion, difficulty in product purification, and high cost of waste catalyst treatment.

[0007] Given the systemic shortcomings of traditional processes in terms of selective control, energy efficiency optimization, and environmental friendliness, and considering the continuously growing market demand for ethylene glycol ether products in fields such as coatings, cleaning agents, and the automotive industry, developing novel production processes that combine high atom economy, low energy consumption, and heterogeneous catalysis advantages has become a key research direction in current chemical process intensification technology. Summary of the Invention

[0008] To address the technical problems existing in the prior art, the present invention aims to provide a production system and method for ethylene glycol ether products that is safe, controllable, and has high product selectivity.

[0009] To achieve the above-mentioned objectives, this invention provides a method for producing ethylene glycol ether products, comprising the following steps:

[0010] Ethylene oxide is mixed with nitrogen and then reacted with preheated alcohol feedstock in an alcohol ether reactor to synthesize ethylene glycol ethers.

[0011] The reaction products in the alcohol-ether reactor are subjected to gas-liquid separation, and the separated gas phase is recovered as the first circulating gas.

[0012] The separated liquid phase is subjected to alcohol removal and staged purification to obtain ethylene glycol ether products of different grades. The gas phase formed after removal is recovered as the second circulating gas. The first circulating gas and the second circulating gas are sent into the alcohol ether reactor after exchanging heat with the alcohol raw material in a preheating heat exchanger.

[0013] According to one technical solution of the present invention, in step S1, the operating temperature of the ethylene glycol ether synthesis reaction is 160-180℃ and the operating pressure is 3.5-4.5MPa.

[0014] According to one technical solution of the present invention, the process of removing alcohol from the separated liquid phase and refining it in stages to obtain ethylene glycol ether products of different grades specifically includes:

[0015] The separated liquid phase undergoes preliminary separation in a de-alcoholization unit, and the second circulating gas is recovered from the gas phase outlet of the de-alcoholization unit;

[0016] The residual liquid product in the de-alcoholization unit is separated by the primary ethylene glycol ether product finishing tower under the first depressurization condition, and the primary ethylene glycol ether product is recovered from the gas phase outlet of the primary ethylene glycol ether product finishing tower.

[0017] The residual liquid product in the primary ethylene glycol ether product finished product tower is separated by depressurization in the secondary ethylene glycol ether product finished product tower, and the secondary ethylene glycol ether product is recovered from the gas phase outlet of the secondary ethylene glycol ether product finished product tower.

[0018] The residual liquid product in the secondary ethylene glycol ether product finished product tower is separated under reduced pressure in the tertiary ethylene glycol ether product finished product tower, and the tertiary ethylene glycol ether product is recovered from the gas phase outlet of the tertiary ethylene glycol ether product finished product tower.

[0019] According to one aspect of the present invention, a production system for ethylene glycol ether products is provided for implementing the above method, comprising a pretreatment unit, an alcohol ether reactor, a first circulating gas recovery unit, and a purification unit;

[0020] The preprocessing unit includes:

[0021] The mixer has its first inlet end and second inlet end connected to the outlet ends of the nitrogen feed source and the ethylene oxide feed source, respectively, and its outlet end connected to the first inlet end of the alcohol ether reactor.

[0022] The circulating gas material preheater has its cold material chamber input end connected to the alcohol raw material source and its output end connected to the second inlet end of the alcohol ether reactor; its hot material chamber input end connected to the outlet end of the first circulating gas recovery unit and its hot material chamber output end connected to the third inlet end of the mixer.

[0023] The refining unit includes a dealcoholization unit, a primary ethylene glycol ether product finished product tower, a secondary ethylene glycol ether product finished product tower, and a tertiary ethylene glycol ether product finished product tower. The gas phase outlet of the dealcoholization unit is connected to the inlet of the first circulating gas recovery unit. The liquid phase outlet of the dealcoholization unit is connected to the inlet of the primary ethylene glycol ether product finished product tower, and the gas phase outlet of the primary ethylene glycol ether product finished product tower is used to recover primary ethylene glycol products. The inlet of the secondary ethylene glycol ether product finished product tower is connected to the liquid phase outlet of the primary ethylene glycol ether product finished product tower, and the gas phase outlet of the secondary ethylene glycol ether product finished product tower is used to recover secondary ethylene glycol products. The inlet of the tertiary ethylene glycol ether product finished product tower is connected to the liquid phase outlet of the secondary ethylene glycol ether product finished product tower, and the gas phase outlet of the tertiary ethylene glycol ether product finished product tower (C204) is used to recover tertiary ethylene glycol products.

[0024] The first circulating gas recovery unit includes:

[0025] A gas-liquid separator is connected to the outlet of the alcohol-ether reactor, and its liquid phase outlet is connected to the inlet of the de-alcoholization unit; its gas phase outlet is connected to the inlet of the circulating gas compressor.

[0026] The inlet of the circulating gas compressor is connected to the gas phase outlet of the gas-liquid separator, and the outlet is connected to the input of the hot material chamber of the circulating gas material preheater.

[0027] According to one technical solution of the present invention, the dealcoholization unit, the primary ethylene glycol ether product finishing tower, the secondary ethylene glycol ether product finishing tower, and the tertiary ethylene glycol ether product finishing tower all comprise:

[0028] A distillation column has a top gas outlet and a bottom liquid outlet.

[0029] The column top condenser has its inlet end connected to the column top gas phase outlet end. The first stream of its outlet end is used to return to the distillation column via the gas phase reflux inlet end, and the second stream of its outlet end is used to recover the column top gas phase stream.

[0030] The reboiler has its inlet end connected to the liquid phase outlet end of the column, and the first stream of material at its outlet end is used to reflux back into the distillation column through the liquid phase reflux inlet end of the distillation column.

[0031] According to one technical solution of the present invention, the operating temperature at the outlet of the cold material chamber of the circulating gas material preheater is 60-90℃ and the operating pressure is 0.1-0.5MPa.

[0032] According to one aspect of the present invention, the partial pressure of nitrogen in the mixer is greater than 60%.

[0033] According to one technical solution of the present invention, the operating temperature of the alcohol-ether reactor is 160-180℃ and the operating pressure is 3.5-4.5MPa;

[0034] The molar ratio of alcohol raw materials to ethylene oxide is 1.5-3:1.

[0035] According to one technical solution of the present invention, in the distillation column of the de-alcoholization unit, the top operating temperature is 115-120℃, the top operating pressure is 100-120kPa, the bottom operating temperature is 160-170℃, and the bottom operating pressure is 110-130kPa; the total reflux ratio is 0.5-3; the theoretical number of plates is 11, and the feed plate is the 4th-7th plate; the heat load of the top condenser of the de-alcoholization unit is 250-280kW, and the heat load of the reboiler is 380-410kW;

[0036] The distillation column of the primary ethylene glycol ether product finishing column operates at 100-110°C, with a top operating pressure of 10-20 kPa, a bottom operating temperature of 150-160°C, a bottom operating pressure of 15-20 kPa, a reflux ratio of 0.3-2, 12 trays, and the feed tray being the 4th to 8th tray. The heat load of the top condenser of the primary ethylene glycol ether product finishing column is 120-150 kW, and the heat load of the reboiler is 80-100 kW.

[0037] In the distillation column of the secondary ethylene glycol ether product finishing column, the top operating temperature is 135-140℃, the top operating pressure is 5-20kPa, the bottom operating temperature is 190-200℃, the bottom operating pressure is 10-20kPa, the reflux ratio is 0.5-2, the number of trays is 12, and the feed tray is the 5th-8th tray; the heat load of the top condenser of the secondary ethylene glycol ether product finishing column is 35-50kW, and the heat load of the reboiler is 35-50kW.

[0038] In the distillation column of the three-stage ethylene glycol ether product finishing column, the top operating temperature is 170-800℃, the top operating pressure is 5-20kPa, the bottom operating temperature is 200-215℃, the bottom operating pressure is 10-20kPa, the reflux ratio is 0.5-3, the number of trays is 10, and the feed tray is the 3rd to 6th tray; the heat load of the top condenser of the three-stage ethylene glycol ether product finishing column is 15-20kW, and the heat load of the reboiler is 15-20kW.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] This invention proposes a low-energy-consumption system and method for producing ethylene glycol ether products. Ethylene oxide and nitrogen are mixed and preheated using a mixer before being fed into an alcohol-ether reactor. Preheated n-butanol is then fed to the top of the reactor. After reaction, the mixture is sent to a gas-liquid separator to separate the unreacted ethylene oxide-nitrogen mixture from the unreacted n-butanol and the resulting ethylene glycol ether product. The ethylene oxide and nitrogen mixture is pressurized by a compressor, deheated by a preheater, and then recycled back to the reactor. The liquid phase collected from the bottom of the separator is sent to a raw material separation tower. After separation, unreacted n-butanol is obtained at the top of the tower, and ethylene glycol ether is obtained at the bottom. The n-butanol is recycled back to the reactor, while the ethylene glycol ether and byproducts enter a refining section for separation and purification. The alcohol-ether reactor improves the controlled stability of the reaction temperature and pressure throughout the system, enabling timely product separation and multi-step distillation, resulting in multiple grades of products with promising industrial application prospects.

[0041] This invention introduces nitrogen gas into the pretreatment tank and establishes a circulation through a recirculation gas loop, so that the nitrogen gas forms a protective atmosphere, keeping the ethylene oxide within its explosion limits and always keeping it under control, thereby improving the safety and stability of the system. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0043] Figure 1 The schematic diagram illustrates the structure of the ethylene glycol ether product production system provided in an embodiment of the present invention.

[0044] The correspondence between component names and reference numerals in the accompanying drawings is as follows:

[0045] M101: Mixer; E101: Circulating gas material preheater; R101: Alcohol ether reactor; T101: Gas-liquid separator; C101: Circulating gas compressor; C201: De-alcoholization unit; C202: Primary ethylene glycol ether product finished product tower; C203: Secondary ethylene glycol ether product finished product tower; C303: Tertiary ethylene glycol ether product finished product tower. Detailed Implementation

[0046] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0047] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0048] like Figure 1 As shown, the present invention provides a method for producing ethylene glycol ether products, comprising the following steps:

[0049] Ethylene oxide is mixed with nitrogen and then reacted with preheated alcohol feedstock in an alcohol ether reactor to synthesize ethylene glycol ethers.

[0050] The reaction products in the alcohol-ether reactor are subjected to gas-liquid separation, and the separated gas phase is recovered as the first circulating gas.

[0051] The separated liquid phase is subjected to alcohol removal and staged purification to obtain different grades of ethylene glycol ether products. The gas phase formed by the removal is recovered as the second circulating gas. The first and second circulating gases exchange heat with the alcohol raw materials in a preheating heat exchanger and are then sent into the alcohol ether reactor.

[0052] In some embodiments of the present invention, in step S1, the operating temperature of the ethylene glycol ether synthesis reaction is 160-180°C and the operating pressure is 3.5-4.5 MPa.

[0053] The present invention also provides a production system for ethylene glycol ether products, including a pretreatment unit, an alcohol ether reactor R101, a first circulating gas recovery unit, and a purification unit;

[0054] The pretreatment unit includes a mixer M101 and a circulating gas material preheater E101.

[0055] The first and second inlet ends of mixer M101 are connected to the outlet ends of nitrogen feedstock and ethylene oxide feedstock, respectively, and the outlet end of mixer M101 is connected to the first inlet end of alcohol ether reactor R101.

[0056] The cold feed chamber of the circulating gas material preheater E101 is connected to the alcohol feedstock source at its inlet, and the output of the circulating gas material preheater E101 is connected to the second inlet of the alcohol-ether reactor R101. The hot feed chamber of the circulating gas material preheater E101 is connected to the outlet of the first circulating gas recovery unit at its inlet, and the output of the hot feed chamber of the circulating gas material preheater E101 is connected to the third inlet of the mixer M101.

[0057] The refining unit includes a dealcoholization unit C201, a primary ethylene glycol ether product finishing tower C202, a secondary ethylene glycol ether product finishing tower C203, and a tertiary ethylene glycol ether product finishing tower C204. The gaseous outlet of the dealcoholization unit C201 is connected to the inlet of the first circulating gas recovery unit, and the liquid outlet of the dealcoholization unit C201 is connected to the inlet of the primary ethylene glycol ether product finishing tower C202. The gaseous outlet of the primary ethylene glycol ether product finishing tower C202 is used to recover primary ethylene glycol products. The inlet of the secondary ethylene glycol ether product finishing tower C203 is connected to the liquid outlet of the primary ethylene glycol ether product finishing tower C202, and the gaseous outlet of the secondary ethylene glycol ether product finishing tower C203 is used to recover secondary ethylene glycol products. The inlet end of the tertiary ethylene glycol ether product finished product tower C204 is connected to the liquid phase outlet end of the secondary ethylene glycol ether product finished product tower C203. The gas phase outlet end of the tertiary ethylene glycol ether product finished product tower C204 is used to recover tertiary ethylene glycol products.

[0058] The first circulating gas recovery unit includes a gas-liquid separator T101 and a circulating gas compressor C101.

[0059] The inlet end of the gas-liquid separator T101 is connected to the outlet end of the alcohol-ether reactor R101, the liquid phase outlet end of the gas-liquid separator T101 is connected to the inlet end of the de-alcoholization unit, and the gas phase outlet of the gas-liquid separator T101 is connected to the inlet of the circulating gas compressor C101.

[0060] The inlet end of the circulating gas compressor C101 is connected to the gas phase outlet end of the gas-liquid separator T101, and the outlet end of the circulating gas compressor C101 is connected to the input end of the hot material chamber of the circulating gas material preheater E101.

[0061] In some embodiments of the present invention, the de-alcoholization unit C201, the primary ethylene glycol ether product finished product tower C202, the secondary ethylene glycol ether product finished product tower C203, and the tertiary ethylene glycol ether product finished product tower C204 all include a distillation column, a top condenser, and a reboiler.

[0062] The distillation column has a top gas outlet and a bottom liquid outlet.

[0063] The inlet end of the condenser at the top of the column is connected to the gas phase outlet end at the top of the column. The first stream of the gas phase at its outlet end is used to return to the distillation column via the gas phase reflux inlet end, and the second stream of the gas phase at its outlet end is used to recover the gas phase stream from the top of the column.

[0064] The inlet of the reboiler is connected to the liquid phase outlet at the bottom of the column, and the first stream of material at its outlet is used to reflux back into the distillation column via the liquid phase reflux inlet.

[0065] In some embodiments of the present invention, the operating temperature at the outlet of the cold material chamber of the circulating gas material preheater E101 is 60-90°C, and the operating pressure is 0.1-0.5 MPa.

[0066] According to some embodiments of the present invention, the partial pressure of nitrogen in mixer M101 is greater than 60%.

[0067] According to some embodiments of the present invention, the operating temperature of the alcohol-ether reactor is 160-180°C and the operating pressure is 3.5-4.5 MPa;

[0068] The molar ratio of alcohol raw materials to ethylene oxide is 1.5-3:1.

[0069] According to some embodiments of the present invention, in the distillation column of the deethanolating unit C201, the top operating temperature is 115-120°C, the top operating pressure is 100-120 kPa, the bottom operating temperature is 160-170°C, and the bottom operating pressure is 110-130 kPa; the total reflux ratio is 0.5-3; the theoretical number of plates is 11, and the feed plate is the 4th-7th plate; the heat load of the top condenser of the deethanolating unit C201 is 250-280 kW, and the heat load of the reboiler is 380-410 kW.

[0070] The C202 distillation column for primary ethylene glycol ether products operates at 100-110℃, with a top operating pressure of 10-20 kPa, a bottom operating temperature of 150-160℃, a bottom operating pressure of 15-20 kPa, a reflux ratio of 0.3-2, 12 trays, and the feed tray being the 4th to 8th tray. The top condenser heat load of the C202 primary ethylene glycol ether product column is 120-150 kW, and the reboiler heat load is 80-100 kW.

[0071] In the C203 distillation column for secondary ethylene glycol ether products, the top operating temperature is 135-140℃, the top operating pressure is 5-20 kPa, the bottom operating temperature is 190-200℃, the bottom operating pressure is 10-20 kPa, the reflux ratio is 0.5-2, the number of trays is 12, and the feed tray is the 5th-8th tray. The heat load of the top condenser and the reboiler of the C203 secondary ethylene glycol ether product distillation column are both 35-50 kW.

[0072] In the C204 distillation column for the finished product of tertiary ethylene glycol ethers, the top operating temperature is 170-800℃, the top operating pressure is 5-20kPa, the bottom operating temperature is 200-215℃, the bottom operating pressure is 10-20kPa, the reflux ratio is 0.5-3, the number of trays is 10, and the feed tray is the 3rd to 6th tray. The heat load of the top condenser and the reboiler of the C204 finished product column for tertiary ethylene glycol ethers is 15-20kW.

[0073] In this invention, the alcohol raw material can be n-butanol, methanol, or ethanol. Since methanol, ethanol, and n-butanol have similar properties, the method in this invention is also applicable to methanol or ethanol-based ethylene glycol ether products.

[0074] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0075] Example 1

[0076] Fresh ethylene oxide and nitrogen from outside the boundary are pretreated in a tank at a pressure of 300 kPa. The feed rates for ethylene oxide are 2375 kg / h and for n-butanol are 5996 kg / h. These are then fed into the alcohol-ether reactor R101 for reaction. The reactor operates at 165°C and 4.0 MPa. The bottom product enters the gas-liquid separator T101, which operates at 150°C and 1.5 MPa. The separated gas phase is used as the first circulating gas and enters the circulating gas compressor C101 at 4.0 MPa. The compressed first circulating gas then enters the circulating gas material preheater E101 to preheat the n-butanol. The liquid phase separated by the gas-liquid separator T101 enters the distillation column of the dealcoholization unit C201. The top operating temperature and pressure of the distillation column in unit C201 are 99°C and 100 kPa, respectively, while the bottom operating temperature and pressure are 105°C and 105 kPa. Unreacted n-butanol is obtained at the top, and a mixture of multiple alcohol ether products is obtained at the bottom. This mixture then enters the primary ethylene glycol ether product column C202, which produces ethylene glycol n-butyl ether. The top operating temperature and pressure of column C202 are 104°C and 10 kPa, respectively, while the bottom operating temperature and pressure are 156°C and 15 kPa. Ethylene glycol monobutyl ether is obtained at the top. Other byproducts enter the secondary ethylene glycol ether product column C203, which produces diethylene glycol n-butyl ether. The diethylene glycol n-butyl ether (DGE) column operates at a top temperature of 133°C and a top pressure of 5 kPa, while the bottom temperature is 191°C and the bottom pressure is 10 kPa. DGE monobutyl ether is obtained at the top. Other byproducts are fed into the tertiary ethylene glycol ether product column C303, which is the heavy component column. The heavy component column operates at a top temperature of 187°C and a top pressure of 5 kPa, while the bottom temperature is 215°C and the bottom pressure is 10 kPa. Triethylene glycol monobutyl ether is obtained at the top. The final output rates are: 4162 kg / h for ethylene glycol monobutyl ether, 996 kg / h for diethylene glycol monobutyl ether, and 265 kg / h for triethylene glycol monobutyl ether.

[0077] Example 2

[0078] Fresh ethylene oxide and nitrogen from outside the boundary are pretreated in a tank at a pressure of 300 kPa. The feed rates for ethylene oxide are 2460 kg / h and methanol are 2590 kg / h. These are then fed to the alcohol-ether reactor R101 for reaction. The reactor operates at 165°C and 4.0 MPa. The product from the reactor bottom enters a gas-liquid separator at 150°C and 1.5 MPa. The separated gas phase is used as the first circulating gas and enters the circulating gas compressor C101 at 4.0 MPa. The compressed first circulating gas then enters the circulating gas material preheater E101 to preheat the n-butanol. The liquid phase separated by the gas-liquid separator T101 enters the distillation column of the dealcoholization unit C201. The top operating temperature and pressure of the distillation column in unit C201 are 64°C and 100 kPa, respectively, while the bottom operating temperature and pressure are 125°C and 105 kPa. Unreacted n-butanol is obtained at the top, and a mixture of multiple alcohol ether products is obtained at the bottom. This mixture then enters the primary ethylene glycol ether product column C202, which produces ethylene glycol methyl ether. The top operating temperature and pressure of column C202 are 63°C and 10 kPa, respectively, while the bottom operating temperature and pressure are 139°C and 15 kPa. Ethylene glycol methyl ether is obtained at the top. Other byproducts enter the secondary ethylene glycol ether product column C203, which produces diethylene glycol methyl ether. The diethylene glycol methyl ether (DGE) column operates at a top temperature of 100°C and a top pressure of 5 kPa, while the bottom temperature is 155°C and the bottom pressure is 10 kPa. DGE is obtained at the top. Other byproducts are fed into the tertiary ethylene glycol ether product column C303, which is the heavy component column. The heavy component column operates at a top temperature of 142°C and a top pressure of 5 kPa, while the bottom temperature is 185°C and the bottom pressure is 10 kPa. Triethylene glycol methyl ether is obtained at the top. The final output rates are: 2675.2 kg / h for DGE, 737.8 kg / h for DGE, and 210 kg / h for Triethylene glycol methyl ether.

[0079] Example 3

[0080] Fresh ethylene oxide and nitrogen from outside the boundary are pretreated in a tank at a pressure of 300 kPa. The ethylene oxide feed rate is 2460 kg / h, and the ethanol feed rate is 3729 kg / h. These are then fed to the alcohol-ether reactor R101 for reaction. The reactor R101 operates at a temperature of 163°C and a pressure of 3.7 MPa. The product from the reactor bottom enters a gas-liquid separator, which operates at a temperature of 155°C and a pressure of 1.5 MPa. The separated gas phase is used as the first circulating gas and enters the circulating gas compressor C101 at a pressure of 3.7 MPa. The compressed first circulating gas then enters the circulating gas material preheater E101 to preheat the n-butanol. The liquid phase separated by the gas-liquid separator T101 enters the distillation column of the dealcoholization unit C201. The top operating temperature and pressure of the distillation column in unit C201 are 77°C and 45 kPa, respectively, while the bottom operating temperature and pressure are 144°C and 50 kPa. Unreacted ethanol is obtained at the top, and a mixture of multiple alcohol ether products is obtained at the bottom. This mixture then enters the primary ethylene glycol ether product column C202, which produces ethylene glycol ethyl ether. The top operating temperature and pressure of column C202 are 72°C and 25 kPa, respectively, while the bottom operating temperature and pressure are 149°C and 40 kPa. Ethylene glycol monoethyl ether is obtained at the top. Other byproducts enter the secondary ethylene glycol ether product column C203, which produces diethylene glycol ethyl ether. The secondary column operates at a top temperature of 108℃ and a top pressure of 15 kPa, while the reboiler operating temperature is 185℃ and the reboiler operating pressure is 20 kPa. Diethylene glycol ethyl ether is obtained at the top. Other byproducts enter the tertiary ethylene glycol ether product column C303, which is the heavy component column. The heavy component column operates at a top temperature of 158℃ and a top pressure of 5 kPa, while the reboiler operating temperature is 175℃ and the reboiler operating pressure is 10 kPa. Triethylene glycol ethyl ether is obtained at the top. The final product flow rates are: 3159 kg / h for ethylene glycol ethyl ether, 820 kg / h for diethylene glycol ethyl ether, and 227 kg / h for triethylene glycol ethyl ether.

[0081] Finally, it should be noted that the above description represents a preferred embodiment of the present invention. It should be pointed out that although preferred embodiments have been described, those skilled in the art, once they understand the basic inventive concept of the present invention, can make various improvements and modifications without departing from the principles described herein. These improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A method for producing ethylene glycol ether products, characterized in that, Includes the following steps: Ethylene oxide is mixed with nitrogen and then reacted with preheated alcohol feedstock in an alcohol ether reactor to synthesize ethylene glycol ethers. The reaction products in the alcohol-ether reactor are subjected to gas-liquid separation, and the separated gas phase is recovered as the first circulating gas. The separated liquid phase is subjected to alcohol removal and staged purification to obtain ethylene glycol ether products of different grades. The gas phase formed after removal is recovered as the second circulating gas. The first circulating gas and the second circulating gas are sent into the alcohol ether reactor after exchanging heat with the alcohol raw material in a preheating heat exchanger.

2. The method for producing ethylene glycol ether products according to claim 1, characterized in that, In step S1, the operating temperature of the ethylene glycol ether synthesis reaction is 160-180℃ and the operating pressure is 3.5-4.5MPa.

3. The method for producing ethylene glycol ether products according to claim 2, characterized in that, The process of removing alcohol from the separated liquid phase and refining it in stages to obtain ethylene glycol ether products of different grades specifically includes: The separated liquid phase undergoes preliminary separation in a de-alcoholization unit, and the second circulating gas is recovered from the gas phase outlet of the de-alcoholization unit; The residual liquid product in the de-alcoholization unit is separated by the primary ethylene glycol ether product finishing tower under the first depressurization condition, and the primary ethylene glycol ether product is recovered from the gas phase outlet of the primary ethylene glycol ether product finishing tower. The residual liquid product in the primary ethylene glycol ether product finished product tower is separated by depressurization in the secondary ethylene glycol ether product finished product tower, and the secondary ethylene glycol ether product is recovered from the gas phase outlet of the secondary ethylene glycol ether product finished product tower. The residual liquid product in the secondary ethylene glycol ether product finished product tower is separated under reduced pressure in the tertiary ethylene glycol ether product finished product tower, and the tertiary ethylene glycol ether product is recovered from the gas phase outlet of the tertiary ethylene glycol ether product finished product tower.

4. A system for producing ethylene glycol ether products, used to implement the method as described in any one of claims 1 to 3, characterized in that, It includes a pretreatment unit, an alcohol-ether reactor, a first circulating gas recovery unit, and a purification unit; The preprocessing unit includes: The mixer has its first inlet end and second inlet end connected to the outlet ends of the nitrogen feed source and the ethylene oxide feed source, respectively, and its outlet end connected to the first inlet end of the alcohol ether reactor. The circulating gas material preheater has its cold material chamber input end connected to the alcohol raw material source and its output end connected to the second inlet end of the alcohol ether reactor; its hot material chamber input end connected to the outlet end of the first circulating gas recovery unit and its hot material chamber output end connected to the third inlet end of the mixer. The refining unit includes a dealcoholization unit, a primary ethylene glycol ether product finished product tower, a secondary ethylene glycol ether product finished product tower, and a tertiary ethylene glycol ether product finished product tower. The gas phase outlet of the dealcoholization unit is connected to the inlet of the first circulating gas recovery unit. The liquid phase outlet of the dealcoholization unit is connected to the inlet of the primary ethylene glycol ether product finished product tower, and the gas phase outlet of the primary ethylene glycol ether product finished product tower is used to recover primary ethylene glycol products. The inlet of the secondary ethylene glycol ether product finished product tower is connected to the liquid phase outlet of the primary ethylene glycol ether product finished product tower, and the gas phase outlet of the secondary ethylene glycol ether product finished product tower is used to recover secondary ethylene glycol products. The inlet of the tertiary ethylene glycol ether product finished product tower is connected to the liquid phase outlet of the secondary ethylene glycol ether product finished product tower, and the gas phase outlet of the tertiary ethylene glycol ether product finished product tower (C204) is used to recover tertiary ethylene glycol products. The first circulating gas recovery unit includes: A gas-liquid separator is connected to the outlet of the alcohol-ether reactor, and its liquid phase outlet is connected to the inlet of the de-alcoholization unit; its gas phase outlet is connected to the inlet of the circulating gas compressor. The inlet of the circulating gas compressor is connected to the gas phase outlet of the gas-liquid separator, and the outlet is connected to the input of the hot material chamber of the circulating gas material preheater.

5. The ethylene glycol ether product production system according to claim 4, characterized in that, The dealcoholization unit, the primary ethylene glycol ether product finished product tower, the secondary ethylene glycol ether product finished product tower, and the tertiary ethylene glycol ether product finished product tower all include: A distillation column has a top gas outlet and a bottom liquid outlet. The column top condenser has its inlet end connected to the column top gas phase outlet end. The first stream of its outlet end is used to return to the distillation column via the gas phase reflux inlet end, and the second stream of its outlet end is used to recover the column top gas phase stream. The reboiler has its inlet end connected to the liquid phase outlet end of the column, and the first stream of material at its outlet end is used to reflux back into the distillation column through the liquid phase reflux inlet end of the distillation column.

6. The ethylene glycol ether product production system according to claim 4, characterized in that, The operating temperature at the outlet of the cold material chamber of the circulating gas material preheater is 60-90℃, and the operating pressure is 0.1-0.5MPa.

7. The ethylene glycol ether product production system according to claim 4, characterized in that, The partial pressure of nitrogen in the mixer is greater than 60%.

8. The ethylene glycol ether product production system according to claim 4, characterized in that, The operating temperature of the alcohol-ether reactor is 160-180℃, and the operating pressure is 3.5-4.5MPa; The molar ratio of alcohol raw materials to ethylene oxide is 1.5-3:

1.

9. The ethylene glycol ether product production system according to claim 5, characterized in that, In the distillation column of the de-alcoholization unit, the top operating temperature is 115-120℃, the top operating pressure is 100-120kPa, the bottom operating temperature is 160-170℃, and the bottom operating pressure is 110-130kPa; the total reflux ratio is 0.5-3; the theoretical number of plates is 11, and the feed plate is the 4th-7th plate; the heat load of the top condenser of the de-alcoholization unit is 250-280kW, and the heat load of the reboiler is 380-410kW; The distillation column of the primary ethylene glycol ether product finishing column operates at 100-110°C, with a top operating pressure of 10-20 kPa, a bottom operating temperature of 150-160°C, a bottom operating pressure of 15-20 kPa, a reflux ratio of 0.3-2, 12 trays, and the feed tray being the 4th to 8th tray. The heat load of the top condenser of the primary ethylene glycol ether product finishing column is 120-150 kW, and the heat load of the reboiler is 80-100 kW. In the distillation column of the secondary ethylene glycol ether product finishing column, the top operating temperature is 135-140℃, the top operating pressure is 5-20kPa, the bottom operating temperature is 190-200℃, the bottom operating pressure is 10-20kPa, the reflux ratio is 0.5-2, the number of trays is 12, and the feed tray is the 5th-8th tray; the heat load of the top condenser of the secondary ethylene glycol ether product finishing column is 35-50kW, and the heat load of the reboiler is 35-50kW. In the distillation column of the three-stage ethylene glycol ether product finishing column, the top operating temperature is 170-800℃, the top operating pressure is 5-20kPa, the bottom operating temperature is 200-215℃, the bottom operating pressure is 10-20kPa, the reflux ratio is 0.5-3, the number of trays is 10, and the feed tray is the 3rd to 6th tray; the heat load of the top condenser of the three-stage ethylene glycol ether product finishing column is 15-20kW, and the heat load of the reboiler is 15-20kW.

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