An ethane-stabilized fuzzy separation system and method for ethylene-ethylene oxide co-process

Abstract

This invention belongs to the fields of intrinsically safe chemical processes and chemical process economics, and discloses a fuzzy separation system and method for ethylene-ethylene oxide combined with ethane stabilization. A mixed feedstock of ethylene and ethane enters an ethylene-ethane distillation column for fuzzy separation. The ethylene-ethane mixture is collected at the top of the column, and the ethane product is collected at the bottom. The feedstock flow rate and the molar ratio of the ethylene-ethane mixture collected at the top are adjusted according to different operating conditions during start-up and stable operation. The mixture is then mixed with pure oxygen and reacted in an ethylene direct oxidation reactor. The generated gas passes through an absorption column, with the top gas serving as the reaction recirculation gas, mixing with the newly separated ethylene-ethane mixture and pure oxygen for a cyclic reaction. The ethylene oxide at the bottom of the absorption column is purified by a stripping column and a refining column to obtain the product ethylene oxide. This invention reduces energy consumption and improves overall economic efficiency while ensuring reaction safety.

Description

Technical Field

[0001] This invention relates to the fields of intrinsically safe chemical processes and the economics and technology of chemical processes, and in particular to a fuzzy separation system and method for ethylene-ethylene oxide combined with ethane stabilization. Background Technology

[0002] Ethylene oxide (EO) is an important organic chemical raw material. Domestically produced ethylene oxide is mainly used to produce ethylene glycol. Its downstream products are abundant, with major applications including sterilization, anti-acidification reactions, rocket and jet fuel, and chain initiators in chain polymerization reactions. Currently, there are two main industrial production methods for ethylene oxide: the chloroethanol method and the direct oxidation of ethylene. The direct oxidation of ethylene is more advanced, suitable for large-scale production, and produces a large quantity of high-quality products (purity up to 99.99%), effectively meeting the needs of downstream products. Therefore, the direct oxidation of ethylene has become the primary method for industrial production of ethylene oxide. Because ethylene has a wide explosive range in oxygen (2.75%–28.6%), the selection of a stabilizing gas, in addition to operating conditions, catalysts, and reaction equipment, is also a crucial technical indicator affecting reaction quality.

[0003] The selection of stabilizing gas involves factors such as safety, stability, and heat transfer capacity. Methane is currently the most commonly used stabilizing gas in the industrial direct oxidation of ethylene to ethylene oxide. Methane stabilization has advantages such as good stability and high safety, but it still has shortcomings compared to ethane stabilization. Ethane is a common chemical product in process production and can serve as a stabilizing gas in the direct oxidation process of ethylene. Ethane has several advantages as a stabilizing gas: First, in the direct oxidation of ethylene oxide by ethylene, both ethylene and ethylene oxide are highly explosive and hazardous materials. As a stabilizing gas, ethane does not participate in the reaction and can effectively dilute the concentration of explosive substances, reducing the explosion range and preventing dangerous overheating explosions, thus greatly improving the safety of the reaction. Second, ethane has significantly higher stability than methane. For example, in an ethylene-oxygen-methane ternary mixture at 2.32 MPa and 250°C, the maximum recommended oxygen concentration and ethylene concentration are as follows: ethylene concentration 8.0% (mol), oxygen concentration 11.8% (mol); ethylene concentration 28.0% (mol), oxygen concentration 10.55% (mol). However, in an ethylene-oxygen-ethane ternary mixture at 2.32 MPa and 250°C, the maximum recommended oxygen concentration and ethylene concentration are as follows: ethylene concentration 8.0% (mol), oxygen concentration 14.55% (mol); ethylene concentration 28.0% (mol), oxygen concentration 13.0% (mol). Thirdly, ethane has better thermal stability than methane. For example, when the molar flow rate of the reactants entering the reactor is the same, and the reaction temperature reaches 265°C after the reaction at 200°C and 2.1 MPa, the oxygen content at the inlet when methane is stabilized is 7.87% (mol), while the oxygen concentration at the inlet when ethane is stabilized can reach 11.64% (mol).

[0004] When ethane stabilization is used in the system, the feed into the ethylene direct oxidation reactor becomes a mixture of ethylene, ethane, and oxygen. Since methane stabilization requires ethylene purity of at least 99.95% (vol)%, this necessitates high-purity separation of ethylene and ethane during the process, leading to high energy consumption. However, by using ethane stabilization, high-purity ethane product at the bottom of the column and a fuzzy separation process at the top, where ethane and ethylene are mixed in a specific ratio (this ratio changes depending on start-up and steady-state operation), can be used for extraction. Under the same feed stream conditions, changing the separation from precise to fuzzy separation saves significant energy, ensuring high safety while conserving energy and improving overall economic efficiency.

[0005] CN 110201487A discloses a method for purifying and reusing high-purity, high-yield methane stabilizing gas in the ethylene process for producing ethylene oxide. This method introduces a new process and improves the utilization rate of methane in the process. However, the process is relatively complex and energy-intensive. The use of methane stabilizing gas results in a lower maximum allowable oxygen content in the reactor and lower reactor efficiency, which limits its industrial application. Summary of the Invention

[0006] The purpose of this invention is to provide a fuzzy separation system and method for ethylene-ethylene oxide combined with ethane stabilization. This involves rationally selecting a new stabilizing gas, using an economical molar ratio of ethylene and oxygen under safe conditions, reducing energy consumption, improving the separation method of the ethylene-ethane distillation column before the ethylene direct oxidation reactor, and selecting appropriate reaction temperature, reaction pressure, and space velocity to enable the reaction performance of the ethylene direct oxidation method to reach an industrial level.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an ethylene-ethylene oxide combined system for fuzzy separation with ethane stabilization, comprising three parts: an ethylene-ethane separation system, an ethylene direct oxidation to ethylene oxide system, and an ethylene oxide refining system; the ethylene-ethane separation system includes an ethylene-ethane distillation column T1 for fuzzy separation; the ethylene direct oxidation to ethylene oxide system includes a mixer MIX, a drying device V1, a carbon dioxide removal device V2, an ethylene direct oxidation reactor R1, an ethylene oxide absorption column T2, a heat exchange device, and a compressor C1; the ethylene oxide refining system includes an ethylene oxide stripping column T3 and an ethylene oxide refining column T4; the bottom of the ethylene-ethane distillation column yields C2H6 product (which can be used as a raw material). (Reaching a purity of 99.95 wt% or higher), the top product of the ethylene ethane distillation column T1 is mixed with pure oxygen in the first heat exchanger H1 and the second heat exchanger H2, respectively, and then mixed in the mixer MIX. The mixture passes through the drying unit V1 and is then fed into the ethylene direct oxidation reactor R1, followed by the third heat exchanger H3, and then to the ethylene oxide absorption column T2. ​​The top product of the ethylene oxide absorption column T2 is fed into the carbon dioxide removal unit V2, and then, after passing through the compressor C1 and the fourth heat exchanger H4, it is recycled back to the mixer MIX. The bottom product of the ethylene oxide absorption column T2 is fed into the ethylene oxide stripping column T3, and the top of the ethylene oxide stripping column T3 is fed into the ethylene oxide refining column T4.

[0008] A combined fuzzy separation method for ethylene-ethylene oxide stabilization is disclosed. The ethylene and ethane mixed feedstock is fed into an ethylene-ethane distillation column T1 for fuzzy separation. Ethane is collected from the bottom of column T1, while the top product, a mixture of ethylene and ethane with varying molar ratios, is obtained as ethylene-ethane mixture 1 after passing through a first heat exchanger H1. Pure oxygen is then passed through a second heat exchanger H2 to obtain oxygen 2. The ethylene-ethane mixture 1 and oxygen 2 are mixed in a mixer MIX to obtain a mixture 3 of ethylene, ethane, and oxygen. The mixture 3 is dried and dehydrated in a drying unit V1 to obtain reactant 4. Reactant 4 is fed into an ethylene direct oxidation reactor R1 for reaction, with part of the heat generated being carried away by a heat transfer agent outside the reactor. After the reaction, product 5 is heated by the third heat exchanger H3 to obtain feed gas 6. Feed gas 6 is fed into the bottom of ethylene oxide absorber T2 to wash away ethylene oxide. Gas 7 from the top of ethylene oxide absorber T2 is successively heated by carbon dioxide removal device V2 and pressurized by compressor C1 to obtain reaction recycle gas 9. Recycle gas 9 is heated by the fourth heat exchanger H4 to obtain reaction recycle gas 10, which enters the mixer and is returned to the mixer as a supplement to the ethylene and ethane consumed in the process flow as the top stream of ethylene ethane distillation tower T1. Liquid mixture 8 from the bottom of ethylene oxide absorber T2 is fed into ethylene oxide stripper T3. Liquid mixture is collected from the bottom of ethylene oxide stripper T3, and gas 11 from the top of ethylene oxide stripper T4 is fed into ethylene oxide refining tower T4. Gas impurities are collected from the top of ethylene oxide refining tower T4, and ethylene oxide product 14 is collected from the bottom.

[0009] The molar ratio of ethane in the ethylene and ethane mixture is 60% to 99%, with the remainder being ethylene.

[0010] The ethylene-ethane distillation column T1 performs fuzzy separation, and the molar ratio of ethylene to ethane in the ethylene and ethane collected from the top of the column is 0% to 70%.

[0011] The feed gas entering the ethylene direct oxidation reactor R1 has an ethylene molar ratio of 5% to 50%, with the remainder being oxygen and stabilizing gas; there is no risk of explosion after the mixture of ethylene, oxygen and stabilizing gas; the reaction temperature inside the ethylene direct oxidation reactor R1 is 150 to 250°C, the reaction pressure is 1.5 MPa to 2.5 MPa, and the space velocity is 10 to 50,000 h⁻¹.

[0012] The ethylene direct oxidation reactor R1 is a tubular fixed-bed reactor, and the catalyst inside is a silver catalyst.

[0013] The molar concentration of the dichloroethane (EDC) inhibitor in the ethylene direct oxidation reactor R1 is 0–3.5E-0.4%.

[0014] The beneficial effects of this invention are as follows: By changing the ethylene-ethane separation method from precise separation to fuzzy separation, this invention reduces significant energy loss, lowers equipment operating costs, and improves the economic efficiency of the process while meeting the requirements of subsequent processes. It employs an economical and environmentally friendly direct oxidation method for ethylene oxide synthesis. While ensuring safety, it increases the maximum permissible oxygen concentration within the reactor, thereby increasing the overall conversion rate of the reaction, improving the economic efficiency of the process, and achieving a level suitable for production. Attached Figure Description

[0015] Figure 1 Schematic diagram of the fuzzy separation system and method for ethylene-ethylene oxide stabilization of ethane;

[0016] Figure 2 This is a separation method for ethylene-ethane distillation columns;

[0017] Figure 3 The relationship between the maximum recommended oxygen concentration and the ethylene concentration in an ethylene-oxygen-stabilizing gas ternary mixture at 2.32 MPa and 250 °C is given.

[0018] In the diagram, T1 is an ethylene-ethane distillation tower; T2 is an ethylene oxide absorption tower; T3 is an ethylene oxide stripping tower; T4 is an ethylene oxide refining tower; H1 is the first heat exchanger, H2 is the second heat exchanger, H3 is the third heat exchanger, and H4 is the fourth heat exchanger; MIX is a mixer; V1 is a dehydration device; V2 is a carbon dioxide removal device; C1 is a compressor; R1 is an ethylene direct oxidation reactor; MIXER is a mixture of ethylene and ethane; 1 is the ethylene-ethane mixture after heat exchange; 2 is the oxygen after heat exchange; 3 is a mixture of ethylene, ethane, and oxygen; 4 is the reactant; 5 is the product after the reaction; 6 is the feed gas; 7 is the gas at the top of the ethylene oxide absorption tower; 8 is the liquid mixture at the bottom of the tower; 9 is the reaction recycle gas; 10 is the reaction recycle gas entering the mixer; 11 is the gas at the top of the ethylene oxide stripping tower; 12 is the liquid mixture; 13 is the gaseous impurities; and 14 is the ethylene oxide product. Detailed Implementation

[0019] An ethylene-ethylene oxide combined system and method for fuzzy separation with ethane stabilization is disclosed. The system comprises three parts: an ethylene-ethane separation system, an ethylene direct oxidation to ethylene oxide system, and an ethylene oxide refining system. The ethylene-ethane separation system includes an ethylene-ethane distillation column; the ethylene direct oxidation to ethylene oxide system includes a mixer, a drying unit, a carbon dioxide removal unit, an ethylene direct oxidation reactor, an ethylene oxide absorption column, multiple heat exchangers, and a compressor; and the ethylene oxide refining system includes an ethylene oxide stripping column and an ethylene oxide refining column. Specifically, T1 is the ethylene-ethane distillation column; T2 is the ethylene oxide absorption column; and T3 is the ethylene oxide stripping column. T4 is an ethylene oxide refining tower; H1, H2, H3, and H4 are heat exchangers; MIX is a mixer; V1 is a dehydration unit; V2 is a carbon dioxide removal unit; C1 is a compressor; R1 is an ethylene direct oxidation reactor. The process is as follows: ethylene and ethane mixed feedstock FEED from other processes enters the ethylene-ethane distillation tower T1 for separation. C2H6 product (reaching over 99.95 wt%) is collected from the bottom of the ethylene-ethane distillation tower. Then, based on the operation of subsequent chemical equipment, the flow rate of the feedstock FEED to the separation tower and the molar ratio of the ethylene and ethane mixture collected from the top stream MIXER are rationally controlled. During startup, the ethylene ethane from the top of the ethylene ethane distillation column T1, after being preheated in H1, is mixed with pure oxygen (O2) preheated in H2 in a certain proportion in the mixer MIX. The mixture then enters V1 for drying and dehydration, and subsequently proceeds to the ethylene direct oxidation reactor R1 for reaction. Part of the heat of reaction generated in R1 is carried away by an external heat transfer agent. The temperature is then reduced in the first heat exchanger H1. The resulting gas 6 is then washed away with ethylene oxide 8 in the water washing column T3. The gas 7 from the top of the ethylene oxide absorber is then heated by compressor C1 and the fourth heat exchanger H4 after carbon dioxide removal in the carbon dioxide removal unit V2. The pressurized reaction recirculation gas 10, which enters the mixer, returns to the mixer MIXER. The flow rate of the ethylene and ethane feed stream FEED and the molar ratio of the MIXER drawn from the top of the ethylene-ethane distillation column T1 need to be controlled to replenish the quantitative ethylene and small amount of ethane consumed during the process. Then, the stream 1, preheated in the first heat exchanger H1, is mixed in the mixer MIXER with the reaction recirculation gas 10 entering the mixer and the oxygen 2 after heat exchange in the second heat exchanger H2, in a certain proportion. The above reaction is then repeated. The ethylene oxide 8 washed out by water is purified by the stripping column T3 and the purification column T4 to obtain the product ethylene oxide. O2 is the feed pure oxygen; H2O-OUT is the water removed by the dehydration unit; COOL-IN is the heat transfer agent entering the ethylene direct oxidation reactor; COOL-OUT is the heat transfer agent leaving the ethylene direct oxidation reactor; H2O is the clean water absorbent entering the ethylene oxide absorption tower.

[0020] The method of this invention reduces energy consumption and improves overall economic efficiency while ensuring reaction safety. The technical solution of this invention will be described in detail below with reference to specific embodiments. These specific embodiments are only used to explain the invention, but the scope of protection of this invention is not limited to these embodiments.

[0021] The method provided by this invention involves first selecting a suitable stabilizing gas, and then determining the maximum permissible oxygen concentration under safe conditions based on the molar concentration of ethylene and the type of stabilizing gas. Figure 3 As shown; next, during start-up, ensure a high molar ratio of ethane to ethylene in the top product of the ethylene ethane distillation column. Mix this with externally added pure oxygen in a suitable molar ratio to form reactants. Then, feed the reactants into a tubular fixed-bed reactor. Control the reaction temperature, pressure, and space velocity to ensure that the reactor outlet yields ethylene oxide meeting industrial requirements. Subsequently, in steady state, the stabilizing gas ethane recycles back to the reactor inlet. At this point, it is necessary to change the feed flow rate of the ethylene ethane distillation column and the molar ratio of ethylene to ethane at the top to ensure that the amount of ethane in the top product can compensate for the amount of stabilizing gas ethane lost during the circulation process. Mix this with externally added pure oxygen in a suitable molar ratio to form reactants. During this process, ensure that the molar ratio of stabilizing gas in the reactants is the same as that of the reactants entering the reactor during start-up. Then, feed the reactants into a tubular fixed-bed reactor. Control the reaction temperature, pressure, and space velocity to ensure that the reactor outlet yields ethylene oxide meeting industrial requirements.

[0022] Example 1

[0023] Nitrogen was selected as the stabilizing gas, and the molar ratios of nitrogen, ethylene, and oxygen were 74.7%, 17.4%, and 7.9%, respectively. The ethylene, oxygen, and nitrogen in the above molar ratios were introduced into the premixed gas to form reactants. At this stage, the reaction poses no explosion hazard. The top product of the ethylene-ethane distillation column is pure ethylene, and the bottom product is pure ethane, achieving precise separation. The reaction gas was then introduced into a tubular reactor, with the reactor inlet temperature controlled at 200°C, the reaction pressure at 2.1 MPa, and the space velocity at 4200 h⁻¹. -1 At this point, the reaction outlet temperature is 250.3℃, and the ethylene oxide outlet concentration is 0.71%. When the feed to the ethylene-ethane distillation column is 4029.51 kmol / hr and the molar ratio of ethylene to ethane is 19.0% and 81.0% respectively, and the bottom of the column is guaranteed to be pure ethane with a mass purity of 99.95%, the heat load of the condenser at the top of the column is -5.26e+07 kJ / hr, and the heat load of the reboiler at the bottom of the column is 4.78e+07 kJ / hr.

[0024] Example 2

[0025] Methane was selected as the stabilizing gas, and the molar ratios of methane, ethylene, and oxygen were 70.6%, 19.3%, and 10.1%, respectively. Ethylene, oxygen, and nitrogen in the above molar ratios were introduced into the premixed gas to form reactants; the reaction at this stage posed no explosion hazard. At this point, the top product of the ethylene-ethane distillation column was pure ethylene, and the bottom product was pure ethane, achieving precise separation. The reaction gas was then introduced into a tubular reactor, with the reactor inlet temperature controlled at 200°C, the reaction pressure at 2.1 MPa, and the space velocity at 4200 h⁻¹. -1 At this point, the reaction outlet temperature is 250.3℃, and the ethylene oxide outlet concentration is 1.0%. When the feed to the ethylene-ethane distillation column is 4029.51 kmol / hr and the molar ratio of ethylene to ethane is 19.0% and 81.0% respectively, and the top and bottom of the column are guaranteed to be pure ethylene and pure ethane with a mass purity of 99.95%, the heat load of the top condenser is -5.26e+07 kJ / hr, and the heat load of the bottom reboiler is 4.78e+07 kJ / hr.

[0026] Example 3

[0027] Ethane was selected as the stabilizing gas, and the molar ratios of ethane, ethylene, and oxygen were 64.2%, 22.9%, and 12.9%, respectively. Ethylene, oxygen, and nitrogen in the above molar ratios were introduced into the premixed gas to form reactants. At this stage, the reaction poses no explosion hazard. Accurate separation is achieved if the top product of the ethylene-ethane distillation column is pure ethylene and the bottom product is pure ethane. The reaction gas was then introduced into a tubular reactor, with the reactor inlet temperature controlled at 200°C, the reaction pressure at 2.1 MPa, and the space velocity at 4200 h⁻¹. -1 At this point, the reaction outlet temperature is 250.3℃, and the ethylene oxide outlet concentration is 1.51%. When the feed to the ethylene-ethane distillation column is 4029.51 kmol / hr and the molar ratio of ethylene to ethane is 19.0% and 81.0% respectively, and the top and bottom of the column are guaranteed to be pure ethylene and pure ethane with a mass purity of 99.95%, the heat load of the top condenser is -5.26e+07 kJ / hr, and the heat load of the bottom reboiler is 4.78e+07 kJ / hr.

[0028] Example 4

[0029] Ethane was selected as the stabilizing gas, and the molar ratios of ethane, ethylene, and oxygen were 64.2%, 22.9%, and 12.9%, respectively. Ethylene, oxygen, and nitrogen in the above molar ratios were introduced into the premixed gas to form reactants. At this stage, the reaction poses no explosion hazard. The top product of the ethylene-ethane distillation column is a mixture of ethylene and ethane, while the bottom product is pure ethane. The reaction gas was then introduced into a tubular reactor, with the reactor inlet temperature controlled at 200°C, the reaction pressure at 2.1 MPa, and the space velocity at 4200 h⁻¹. -1At this point, the reaction outlet temperature is 250.3℃, and the ethylene oxide outlet concentration is 1.51%. When the feed rate to the ethylene-ethane distillation column is 4029.51 kmol / hr and the molar ratio of ethylene to ethane is 19.0% and 81.0% respectively, and the bottom of the column is guaranteed to be pure ethane with a purity of not less than 99.95%, the molar ratio of ethylene to ethane at the top of column T1 during start-up is 30.6% and 69.4%, respectively. At this time, the heat load of the top condenser is -3.14e+07 kJ / hr, and the heat load of the bottom reboiler is 5.27e+07 kJ / hr. During stable operation, the flow rate into the ethylene-ethane distillation column is 347.035 kmol / hr, and the molar ratio of ethylene to ethane at the top is 98.77% and 1.23%, respectively. The heat load of the top condenser is -4.49e+06 kJ / hr, and the heat load of the bottom reboiler is 4.04e+06 kJ / hr.

[0030] Comparative Examples 1, 2, and 3:

[0031] The maximum allowable oxygen content in the reaction is an important indicator for evaluating the quality of the direct oxidation reaction of ethylene. By comparing Examples 1, 2 and 3, it can be seen that, under the same conditions of inlet molar flow rate, temperature, pressure, space velocity and outlet temperature, ethane stabilized gas, compared with nitrogen and methane stabilized gas, not only increases the maximum allowable oxygen concentration, but also increases the conversion rate of the reaction, thereby improving the economic efficiency of the process while ensuring safety.

[0032] Comparative Examples 3 and 4:

[0033] In the process of producing ethylene oxide via the direct oxidation of ethylene, when ethane is used as the stabilizing gas and then supplied as the reactant in an ethylene-ethane distillation column, fuzzy separation can be achieved. When the ethylene-ethane column achieves precise separation with 99.95% (wt) ethylene at the top and 99.95% (wt) ethane at the bottom, the energy consumption is -4.84e+0.7 kJ / hr for the top condenser and 6.40e+0.7 kJ / hr for the bottom reboiler. After using ethane as the stabilizing gas, fuzzy separation is performed. During start-up, the heat load of the overhead condenser is -3.14e+07 kJ / hr, and the heat load of the bottom reboiler is 5.27e+07 kJ / hr. During stable operation, when the molar ratio of ethylene to ethane at the top of the column is 98.77% and 1.23%, the heat load of the overhead condenser is -4.49e+06 kJ / hr, and the heat load of the bottom reboiler is 4.04e+06 kJ / hr. This demonstrates that significant energy consumption is saved during both start-up and stable operation.

Claims

1. An ethane-stabilized fuzzy separation system for ethylene-ethylene oxide, characterized in that, This ethylene-ethylene oxide stabilization fuzzy separation combined system comprises three parts: an ethylene ethane separation system, an ethylene direct oxidation to ethylene oxide system, and an ethylene oxide refining system. The ethylene ethane separation system includes an ethylene ethane distillation column (T1) for fuzzy separation. The ethylene direct oxidation to ethylene oxide system includes a mixer (MIX), a drying unit (V1), a carbon dioxide removal unit (V2), an ethylene direct oxidation reactor (R1), an ethylene oxide absorption column (T2), a heat exchanger, and a compressor (C1). The ethylene oxide refining system includes an ethylene oxide stripping column (T3) and an ethylene oxide refining column (T4). The top product of the ethylene ethane distillation column (T1) and pure oxygen are respectively... After heat exchange in the first heat exchanger (H1) and the second heat exchanger (H2), the mixture is mixed in the mixer (MIX). The mixture passes through the drying unit (V1) and then into the ethylene direct oxidation reactor (R1), followed by heat exchange in the third heat exchanger (H3), and then into the ethylene oxide absorber (T2). The top product of the ethylene oxide absorber (T2) is fed into the carbon dioxide removal unit (V2), and then through the compressor (C1) and the fourth heat exchanger (H4) before being recycled back to the mixer (MIX). The bottom product of the ethylene oxide absorber (T2) is fed into the ethylene oxide stripping tower (T3), and the top of the ethylene oxide stripping tower (T3) leads to the ethylene oxide refining tower (T4).

2. A fuzzy separation method for ethylene-ethylene oxide co-stabilization, characterized in that, Ethylene and ethane mixed feedstock enter the ethylene-ethane distillation column (T1) for fuzzy separation; ethane product is collected from the bottom of the ethylene-ethane distillation column (T1), and the top product of the ethylene-ethane distillation column (T1) is a mixture of ethylene and ethane with different molar ratios. After passing through the first heat exchanger (H1), the heat-exchanged ethylene-ethane mixture (1) is obtained; pure oxygen is passed through the second heat exchanger (H2) to obtain heat-exchanged oxygen (2); the heat-exchanged ethylene-ethane mixture (1) and the heat-exchanged oxygen (2) are mixed in the mixer (MIX) to obtain a mixture of ethylene, ethane and oxygen (3); the mixture of ethylene, ethane and oxygen (3) is dried and dehydrated by the drying device (V1) to obtain reactant (4); reactant (4) is fed into the ethylene direct oxidation reactor (R1) for reaction, in which ethane acts as a stabilizing gas, and part of the heat of reaction generated by the reaction is carried away by the heat transfer agent outside the reactor. The product after the reaction is completed (5) The feed gas (6) is obtained by heat exchange through the third heat exchanger (H3); the feed gas (6) is fed into the bottom of the ethylene oxide absorber (T2) to wash away the ethylene oxide; the gas (7) at the top of the ethylene oxide absorber is passed through the carbon dioxide removal device (V2) to remove carbon dioxide, and then pressurized by the compressor (C1) to obtain the reaction cycle gas (9); the reaction cycle gas (9) is heat exchanged through the fourth heat exchanger (H4) to obtain the reaction cycle gas (10) entering the mixer, and then returned to the mixer. In the process, the ethylene and ethane consumed in the process are supplemented by the overhead stream of the ethylene ethane distillation tower (T1); the liquid mixture (8) at the bottom of the ethylene oxide absorption tower (T2) is fed into the ethylene oxide stripping tower (T3); the liquid mixture is collected from the bottom of the ethylene oxide stripping tower (T3), and the gas (11) at the top of the ethylene oxide stripping tower is fed into the ethylene oxide refining tower (T4); the gas impurities are collected from the top of the ethylene oxide refining tower (T4), and the ethylene oxide product (14) is collected from the bottom.

3. The fuzzy separation method for ethylene-ethylene oxide stabilization according to claim 2, characterized in that, The molar ratio of ethane in the ethylene and ethane mixture is 60% to 99%, with the remainder being ethylene.

4. The fuzzy separation method for ethylene-ethylene oxide stabilization according to claim 2 or 3, characterized in that, The ethylene-ethane distillation column (T1) performs fuzzy separation, and the molar ratio of ethylene to ethane in the ethylene and ethane collected from the top of the column is 0%~70%.

5. The fuzzy separation method for ethylene-ethylene oxide stabilization according to claim 4, characterized in that, The reactant (4) entering the ethylene direct oxidation reactor (R1) has an ethylene molar ratio of 5% to 50%, with the remainder being oxygen and stabilizing gas; there is no risk of explosion after the ethylene, oxygen and stabilizing gas are mixed; the reaction temperature in the ethylene direct oxidation reactor (R1) is 150 to 250°C, the reaction pressure is 1.5 MPa to 2.5 MPa, and the space velocity is 10 to 50,000 h⁻¹.

6. The fuzzy separation method for ethylene-ethylene oxide stabilization according to claim 2, 3, or 5, characterized in that, The ethylene direct oxidation reactor (R1) is a tubular fixed-bed reactor with a silver catalyst inside.

7. The fuzzy separation method for ethylene-ethylene oxide stabilization according to claim 6, characterized in that, The molar concentration of the inhibitor dichloroethane (EDC) in the ethylene direct oxidation reactor (R1) is 0~3.5E-04%.

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