Process device for producing ethylene oxide from ethane

Abstract

The utility model relates to the technical field of ethylene oxide processing, in particular to a process device for producing ethylene oxide from ethane, which comprises an ethane oxidative dehydrogenation device, equipment for preparing ethylene oxide from ethylene, a gas-liquid separator, an ethylene oxide rectifying tower, an ethylene rectifying tower and a deethanizing tower which are sequentially connected along the main material flow direction, a product gas outlet of the ethane oxidative dehydrogenation device passes through a gas-liquid separator, is pressurized by a compressor and then is connected with equipment for preparing ethylene oxide from ethylene, a gas outlet of the equipment for preparing ethylene oxide from ethylene is connected with the gas-liquid separator, and an outlet of the gas-liquid separator is connected with an ethylene rectifying tower; and the outlet of the ethylene rectifying tower is connected with the deethanizing tower. According to the utility model, the ethane oxidative dehydrogenation device C2H6 + 0.5 O2-> C2H4 + H2O and the ethylene-to-ethylene oxide device C2H4 + 0.5 O2-> C2H4O are used for realizing the generation of ethylene and ethylene oxide by dehydrogenation of ethane as a raw material under mild reaction conditions, so that the richness of ethane oxidative dehydrogenation products is improved, and the adaptability of the process to the market is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ethylene oxide processing, in particular to a process device for producing ethylene oxide from ethane. Background Art

[0002] Ethylene (C2H4) is one of the world's most produced chemical products and a key chemical raw material, primarily used in synthetic fibers, rubber, plastics, acrylic fibers, adhesives, and other chemicals. Currently, ethylene accounts for over 40% of organic chemicals and approximately 75% of petrochemical products, making it a crucial component of the national economy. The scale, technology, and output of ethylene production are now considered key indicators of a country's petrochemical development.

[0003] In recent years, with the development of shale gas technology in North America, the cost of producing ethylene using ethane as a feedstock through thermal cracking has been significantly reduced, leading to the establishment of numerous low-carbon alkane cracking plants in China. However, ethane thermal cracking is an endothermic reaction, subject to thermodynamic constraints. Reaction temperatures exceeding 900°C result in high energy consumption, prone to carbon deposition and coking in the cracking furnace, and complex equipment and high operating costs. In comparison, ethane oxidative dehydrogenation (ODHE) offers a promising alternative process. Due to its exothermic nature, it can effectively overcome equilibrium conversion and carbon deposition issues while lowering the reaction temperature. Existing ethylene oxide production processes primarily use ethylene as a feedstock via selective oxidation over a silver-based catalyst. Compared to ethane, which is more expensive to produce as a feedstock, ethylene offers significant cost advantages. Furthermore, ethane is easier to obtain as a feedstock and facilitates the miniaturization of the reactor. Therefore, producing ethylene oxide using ethane as a feedstock offers significant economic and technical advantages. Utility Model Content

[0004] In response to the above problems, the purpose of this utility model is to design and propose a process device for producing ethylene oxide from ethane, which realizes the production of ethylene oxide using ethane as raw material under mild reaction conditions through an ethane oxidative dehydrogenation device C2H6+0.5O2→C2H4+H2O and an ethylene selective oxidation device for preparing ethylene oxide C2H4+0.5O2→C2H4O.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A process device for producing ethylene oxide from ethane comprises an ethane oxidative dehydrogenation device, ethylene oxide preparation equipment, a gas-liquid separator, an ethylene oxide distillation tower, an ethylene distillation tower and a deethanizer, which are sequentially connected along the main material flow direction. The product gas outlet of the ethane oxidative dehydrogenation device passes through the gas-liquid separator, is pressurized by a compressor and then connected to the ethylene oxide preparation equipment. The gas outlet of the ethylene oxide preparation equipment is connected to the gas-liquid separator, the gas-liquid separator outlet is connected to the ethylene distillation tower, and the ethylene distillation tower outlet is connected to the deethanizer.

[0007] As a further description of the above technical solution:

[0008] The gas inlet end of the ethane oxidative dehydrogenation device is provided with a gas mixing device, and the gas mixing device is respectively provided with three gas inlet branches, namely an oxygen branch, an ethane branch and an inert gas branch.

[0009] As a further description of the above technical solution:

[0010] The ethylene oxide preparation equipment is equipped with an oxygen gas line, which is connected to the oxygen branch pipe through a first pipeline, and a first control valve is provided on the first pipeline.

[0011] As a further description of the above technical solution:

[0012] The reaction tail gas of the ethylene preparation ethylene oxide equipment is separated by a gas-liquid separator and then enters an ethylene distillation tower and a deethanizer in sequence. The ethane outlet of the deethanizer is connected to the ethane branch pipe through a second pipeline, and a second control valve is provided on the second pipeline.

[0013] As a further description of the above technical solution:

[0014] The liquid product separated by the gas-liquid separator enters the ethylene oxide distillation tower.

[0015] As a further description of the above technical solution:

[0016] A condenser is connected between the ethane oxidative dehydrogenation device and the gas-liquid separator.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] The present invention increases the utilization of ethylene in the product, enhances the product diversity of the ethane oxidative dehydrogenation process, and improves the market adaptability of the process. The process apparatus significantly reduces the energy consumption of ethylene production by ethane thermal cracking. Compared with conventional ethane oxidative dehydrogenation process apparatus, the process significantly improves the utilization rate of raw materials, reduces the number of product production equipment, and greatly improves the economic efficiency of the process route. It can achieve low-energy and high-efficiency ethane oxidation to produce ethylene oxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The utility model provides a schematic structural diagram of a process device for producing ethylene oxide from ethane.

[0020] Legend:

[0021] 1. Ethane oxidative dehydrogenation unit; 2. Condenser; 3. Gas-liquid separator; 4. Ethylene oxide preparation equipment; 5. Ethylene oxide distillation tower; 6. Ethylene distillation tower; 7. Deethanizer; 8. Compressor; 9. Gas mixing equipment; 901. Oxygen branch pipe; 902. Ethane branch pipe; 903. Inert gas branch pipe; 10. First pipeline; 11. First control valve; 12. Second pipeline; 13. Second control valve. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0023] Please refer to 1. The present invention provides a technical solution: a process device for producing ethylene oxide from ethane, comprising an ethane oxidative dehydrogenation device 1, an ethylene oxide preparation device 4, a gas-liquid separator 3, an ethylene oxide distillation tower 5, an ethylene distillation tower 6 and a deethanizer 7 which are sequentially connected along the main material flow direction. The product gas outlet of the ethane oxidative dehydrogenation device 1 passes through the gas-liquid separator 3 and is pressurized by a compressor 8 before being connected to the ethylene oxide preparation device 4. The gas outlet of the ethylene oxide preparation device 4 is connected to the gas-liquid separator 3, the outlet of the gas-liquid separator 3 is connected to the ethylene distillation tower 6, and the outlet of the ethylene distillation tower 6 is connected to the deethanizer 7.

[0024] The device generates ethylene oxide by reacting ethylene generated in the ethylene oxidative dehydrogenation reaction with oxygen (introduced separately). The reaction tail gas of the ethylene preparation ethylene oxide device 4 enters the ethylene oxide distillation tower 5 after gas-liquid separation to obtain high-purity ethylene oxide. The reaction tail gas is separated by the ethylene distillation tower 6 to obtain polymerization-grade ethylene. The ethane in the tail gas is purified by the deethanizer 7 and then injected into the ethane oxidative dehydrogenation device 1 again.

[0025] Specifically, such as Figure 1 As shown, the gas inlet end of the ethane oxidative dehydrogenation device 1 is provided with a gas mixing device 9, and three gas inlet branches are respectively provided on the gas mixing device 9, namely an oxygen branch 901, an ethane branch 902 and an inert gas branch 903. The gas mixing device 9 is used to receive and mix ethane, oxygen and inert gas (such as nitrogen) from the three gas inlet branches, mix and preheat the raw gas, and then transport it to the ethane oxidative dehydrogenation device 1.

[0026] Specifically, such as Figure 1 As shown, the ethylene preparation ethylene oxide device 4 is equipped with an oxygen gas circuit, which is connected to the oxygen branch pipe 901 through a first pipeline 10, and a first control valve 11 is provided on the first pipeline 10. The reaction tail gas of the ethylene preparation ethylene oxide device 4 is separated by the gas-liquid separator 3 and then enters the ethylene distillation tower 6 and the deethanizer 7 in sequence. The ethane outlet of the deethanizer 7 is connected to the ethane branch pipe 902 through a second pipeline 12, and a second control valve 13 is provided on the second pipeline 12.

[0027] After being processed by the deethanizer 7, the unreacted ethane is returned to the ethane branch pipe 902 via the second pipeline 12, and then enters the gas mixing device 9 to be mixed with oxygen and inert gas for preheating.

[0028] The liquid separated by the gas-liquid separator 3 enters the ethylene oxide distillation tower 5, and is finally separated to obtain high-purity ethylene oxide.

[0029] Specifically, the liquid product separated by the gas-liquid separator 3 enters the ethylene oxide distillation tower 5. A condenser 2 is connected between the ethane oxidative dehydrogenation device 1 and the gas-liquid separator 3. The condenser 2 can accelerate the gas liquefaction process, thereby ensuring the efficiency and stability of gas-liquid separation.

[0030] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for producing ethylene oxide from ethane, characterized in that: The invention comprises an ethane oxidative dehydrogenation device (1), an ethylene preparation ethylene oxide device (4), a gas-liquid separator (3), an ethylene oxide rectification tower (5), an ethylene rectification tower (6) and a deethanizer (7) which are sequentially connected along the main material flow direction. The product gas outlet of the ethane oxidative dehydrogenation device (1) passes through the gas-liquid separator (3) and is pressurized by a compressor (8) before being connected to the ethylene preparation ethylene oxide device (4). The gas outlet of the ethylene preparation ethylene oxide device (4) is connected to the gas-liquid separator (3), the outlet of the gas-liquid separator (3) is connected to the ethylene rectification tower (6), and the outlet of the ethylene rectification tower (6) is connected to the deethanizer (7).

2. A process for producing ethylene oxide from ethane according to claim 1, characterized in that: The gas inlet end of the ethane oxidative dehydrogenation device (1) is provided with a gas mixing device (9), and the gas mixing device (9) is provided with three gas inlet branches, namely an oxygen branch (901), an ethane branch (902) and an inert gas branch (903).

3. A process for producing ethylene oxide from ethane according to claim 2, characterized in that: The ethylene oxide production equipment (4) is equipped with an oxygen gas line, which is connected to the oxygen branch pipe (901) through a first pipeline (10), and a first control valve (11) is provided on the first pipeline (10).

4. A process for producing ethylene oxide from ethane according to claim 2, characterized in that: The reaction tail gas of the ethylene preparation ethylene oxide device (4) is separated by a gas-liquid separator (3) and then enters an ethylene distillation tower (6) and a deethanizer (7) in sequence. The ethane outlet of the deethanizer (7) is connected to the ethane branch pipe (902) through a second pipeline (12), and a second control valve (13) is provided on the second pipeline (12).

5. The process for producing ethylene oxide from ethane according to claim 1, characterized in that: The liquid product separated by the gas-liquid separator (3) enters the ethylene oxide distillation tower (5).

6. The process for producing ethylene oxide from ethane according to claim 1, characterized in that: A condenser (2) is connected between the ethane oxidative dehydrogenation device (1) and the gas-liquid separator (3).

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