C2 fraction selective hydrogenation method in progressive separation flow

Abstract

The invention provides a C2 fraction selective hydrogenation method in progressive separation flow. After hydrogen coordination, C2 fraction from a dethanizer enters into a fixed bed catalytic reactor to be subjected to selective hydrogenation for removing acetylene out of the C2 fraction. In the invention, after the processing of a first section hydrogenation reactor, a part of material is introduced into a front end device of the fixed bed catalytic reactor so as to reduce pollution of side products produced by the first section hydrogenation reactor to catalyst of a second section hydrogenation reactor and dilute acetylene at the inlet of the first section hydrogenation reactor, thereby effectively protecting the performance of the catalyst of the second hydrogenation reactor, improving the hydrogenation selectivity and the increment of ethylene, and increasing the economic benefits of the operation of devices.

Description

technical field

[0001] The invention relates to a selective hydrogenation method, in particular to a method for selective hydrogenation and removal of acetylene from carbon distillates in a sequential separation process. Background technique

[0002] The production of polymer grade ethylene is the leader in the petrochemical industry. Polymer grade ethylene and propylene are the most basic raw materials for downstream polymerization units. In addition to ensuring that the acetylene content at the outlet of the hydrogenation reactor is up to standard, the catalyst has excellent selectivity and can minimize ethylene. The formation of ethane is of great significance for improving the ethylene yield of the whole process and improving the economic benefits of the device.

[0003] The cracked carbon distillate contains acetylene with a mole fraction of 0.5% to 2.5%. When producing polyethylene, a small amount of acetylene in ethylene will reduce the activity of the polymerization ...

Examples

Embodiment 1

[0032] Example 1 Reflux 1%

[0033] Refer to attached figure 1 , with attached figure 1 The difference is that the three-stage hydrogenation reactor process is adopted, and the catalyst loading capacity of each stage reactor is 5m 3 , 1.4% (V / V) of acetylene at the inlet of the first-stage hydrogenation reactor, and the total material volume at the inlet of the first-stage hydrogenation reactor is 40400Nm 3 / h, the reflux rate accounts for 1% of the total material volume, the material refluxes to the water washing tower, and the total material volume at the inlet of the second-stage hydrogenation reactor is 39996Nm 3 / h, the total material volume at the inlet of the three-stage hydrogenation reactor is 39996Nm 3 / h, after the hydrogenation reactor in the first stage, there is a green oil tank in front of the heat exchanger; the catalyst is LY-C 2 -O2, reaction pressure 1.0MPa. The extraction point of the reflux material is the bottom of the green oil tank. Catalyst opera...

Embodiment 2

[0039] Example 2 Reflux 10%

[0040] Three-stage hydrogenation reactor process, the catalyst loading capacity of each stage reactor is 7m 3 , 1 stage hydrogenation reactor inlet material 15400Nm 3 / h, reflux rate 10%, refer to attached figure 1 , the material is refluxed to the oil washing tower, and the material output part is the bottom of the heat exchanger after the first hydrogenation reactor, and the total material volume at the inlet of the second and third hydrogenation reactors is 13860Nm 3 / h. The catalyst is German Southern Chemical G-58C, and the reaction pressure is 1.5MPa. After reflux, the acetylene at the inlet of the first-stage hydrogenation reactor is 1.89% (V / V). Catalyst operating data are shown in Table 2.

Embodiment 3

[0047] Example 3 reflux 50%

[0048] Two-stage hydrogenation reactor process, the first-stage hydrogenation reactor catalyst loading capacity is 15m 3 , the catalyst loading capacity of the second-stage hydrogenation reactor is 10m 3 , 1.0% (V / V) of acetylene at the inlet of the first-stage hydrogenation reactor, and the total material volume at the inlet of the first-stage hydrogenation reactor is 69000Nm 3 / h, the reflux after the first hydrogenation reactor is 34500Nm 3 / h, with attached figure 1 In the process shown, the catalyst is Southern Chemical G-58C, and the reaction pressure is 2.5MPa. The extraction point of the reflux material is located at the bottom of the heat exchanger. Catalyst operating data are shown in Table 3.

technical field

[0001] The invention relates to a selective hydrogenation method, in particular to a method for selective hydrogenation and removal of acetylene from carbon distillates in a sequential separation process. Background technique

[0002] The production of polymer grade ethylene is the leader in the petrochemical industry. Polymer grade ethylene and propylene are the most basic raw materials for downstream polymerization units. In addition to ensuring that the acetylene content at the outlet of the hydrogenation reactor is up to standard, the catalyst has excellent selectivity and can minimize ethylene. The formation of ethane is of great significance for improving the ethylene yield of the whole process and improving the economic benefits of the device.

[0003] The cracked carbon distillate contains acetylene with a mole fraction of 0.5% to 2.5%. When producing polyethylene, a small amount of acetylene in ethylene will reduce the activity of the polymerization ...

Examples

Embodiment 1

[0032] Example 1 Reflux 1%

[0033] Refer to attached figure 1 , with attached figure 1 The difference is that the three-stage hydrogenation reactor process is adopted, and the catalyst loading capacity of each stage reactor is 5m 3 , 1.4% (V / V) of acetylene at the inlet of the first-stage hydrogenation reactor, and the total material volume at the inlet of the first-stage hydrogenation reactor is 40400Nm 3 / h, the reflux rate accounts for 1% of the total material volume, the material refluxes to the water washing tower, and the total material volume at the inlet of the second-stage hydrogenation reactor is 39996Nm 3 / h, the total material volume at the inlet of the three-stage hydrogenation reactor is 39996Nm 3 / h, after the hydrogenation reactor in the first stage, there is a green oil tank in front of the heat exchanger; the catalyst is LY-C 2 -O2, reaction pressure 1.0MPa. The extraction point of the reflux material is the bottom of the green oil tank. Catalyst opera...

Embodiment 2

[0039] Example 2 Reflux 10%

[0040] Three-stage hydrogenation reactor process, the catalyst loading capacity of each stage reactor is 7m 3 , 1 stage hydrogenation reactor inlet material 15400Nm 3 / h, reflux rate 10%, refer to attached figure 1 , the material is refluxed to the oil washing tower, and the material output part is the bottom of the heat exchanger after the first hydrogenation reactor, and the total material volume at the inlet of the second and third hydrogenation reactors is 13860Nm 3 / h. The catalyst is German Southern Chemical G-58C, and the reaction pressure is 1.5MPa. After reflux, the acetylene at the inlet of the first-stage hydrogenation reactor is 1.89% (V / V). Catalyst operating data are shown in Table 2.

Embodiment 3

[0047] Example 3 reflux 50%

[0048] Two-stage hydrogenation reactor process, the first-stage hydrogenation reactor catalyst loading capacity is 15m 3 , the catalyst loading capacity of the second-stage hydrogenation reactor is 10m 3 , 1.0% (V / V) of acetylene at the inlet of the first-stage hydrogenation reactor, and the total material volume at the inlet of the first-stage hydrogenation reactor is 69000Nm 3 / h, the reflux after the first hydrogenation reactor is 34500Nm 3 / h, with attached figure 1 In the process shown, the catalyst is Southern Chemical G-58C, and the reaction pressure is 2.5MPa. The extraction point of the reflux material is located at the bottom of the heat exchanger. Catalyst operating data are shown in Table 3.

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