Tail gas recovery device for oil absorption tower of butadiene preparation system

Abstract

The utility model discloses a tail gas recovery device for an oil absorption tower of a butadiene preparation system. The tail gas recovery device comprises an adsorption tower, a cooler, a recovery tank and a turbine generator, the tail gas recovery device has the advantages that the tail gas discharged by the oil absorption tower is adsorbed by the adsorption tower, effective components such as C6 and C7 in the tail gas are recovered, the cooling capacity of the tail gas of the adsorption tower is recovered by the rectifying tower condenser of the MTBE device, and the high-pressure energy of the tail gas of the adsorption tower can be used for power generation of the turbine generator; meanwhile, the cooling capacity and high-pressure energy of the tail gas of the absorption tower can be further utilized, and the purposes of energy conservation and consumption reduction are achieved.

Description

Technical Field:

[0001] The utility model relates to the technical field of butadiene production, and specifically relates to a tail gas recovery device for an oil absorption tower in a butadiene preparation system. Background Art:

[0002] Butene oxidative dehydrogenation is the main synthetic method for producing butadiene. The generated gas mainly contains hydrocarbons such as butadiene, cis-butene, and trans-butene, as well as impurities such as nitrogen, ketones, aldehydes, and acids. In order to separate hydrocarbons and impurities, the generated gas needs to enter water-cooled washing and purification first to wash away ketones, aldehydes, and acids, and then enter the oil absorption unit after compression. In the oil absorption tower, absorption oil (C 6、 C7) is used to absorb hydrocarbons, and then the hydrocarbons are desorbed and cooled from the absorption oil to obtain crude butadiene. The tail gas discharged from the oil absorption tower carries absorption oil and C 6、 C7. If directly discharged to the flare, it will cause waste of energy. Summary of the Utility Model:

[0003] The purpose of the utility model is to provide a tail gas recovery device for an oil absorption tower in a butadiene preparation system.

[0004] The utility model is implemented by the following technical solutions: A tail gas recovery device for an oil absorption tower in a butadiene preparation system includes an adsorption tower, a cooler, a recovery tank, and a turbo generator. The tail gas discharge port at the top of the oil absorption tower is respectively communicated with the bottom material ports of two adsorption towers through a feed pipe, and a feed control valve is installed on the feed pipe; the bottom material ports of the two adsorption towers are respectively communicated with the inlet of the cooler through an oil discharge pipe, and an oil discharge control valve is installed on the oil discharge pipe; the bottom oil discharge port of the cooler is communicated with the inlet of the recovery tank; the top material ports of the two adsorption towers are respectively communicated with a steam pipe through a regeneration pipe, and a regeneration control valve is installed on the regeneration pipe; the top material ports of the two adsorption towers are respectively communicated with the cold medium inlet of the rectification tower condenser of the MTBE device through a tail gas pipe, and a tail gas control valve is installed on the tail gas pipe; the cold medium outlet of the rectification tower condenser is communicated with the air inlet of the turbo generator, and an exhaust pipe is communicated with the exhaust port of the turbo generator.

[0005] Further, the cooler includes a first cooler and a second cooler. The outlet of the oil discharge pipe is communicated with the inlet of the first cooler, the exhaust port of the first cooler is communicated with the inlet of the second cooler, and the oil discharge ports of the first cooler and the second cooler are both communicated with the inlet of the recovery tank.

[0006] Further, the exhaust port of the recovery tank is communicated with the inlet of the second cooler.

[0007] Advantages of the present utility model: The tail gas discharged from the oil absorption tower is adsorbed by the adsorption tower to recover the effective components such as C 6、 C7, etc. Moreover, the cold energy of the tail gas of the adsorption tower is recovered by the rectifying tower condenser of the MTBE unit, and the high-pressure energy of the tail gas of the adsorption tower is used to generate electricity by the turbo generator. With this device, the effective components in the tail gas of the oil absorption tower can be recovered, and at the same time, the cold energy and high-pressure energy of the tail gas of the absorption tower can be further utilized, achieving the purpose of energy conservation and consumption reduction. Description of the drawings:

[0008] Figure 1 It is a schematic diagram of the overall structure of this embodiment.

[0009] Adsorption tower 1, first cooler 2, recovery tank 3, turbo generator 4, oil absorption tower 5, feed pipe 6, feed control valve 7, oil outlet pipe 8, oil outlet control valve 9, regeneration pipe 10, regeneration control valve 11, tail gas pipe 12, rectifying tower condenser 13, tail gas control valve 14, exhaust pipe 15, second cooler 16. Specific implementation manners:

[0010] In the description of the present utility model, it should be noted that when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present utility model. In addition, when terms such as "first", "second", "third" appear, they are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0011] Such as Figure 1As shown in the figure, a tail gas recovery device for a butadiene preparation system's oil absorption tower includes an adsorption tower 1, a cooler, a recovery tank 3, and a turbo generator 4. The tail gas discharge port at the top of the oil absorption tower 5 is connected to the bottom material ports of two adsorption towers 1 through a feed pipe 6, and a feed control valve 7 is installed on the feed pipe 6; the bottom material ports of the two adsorption towers 1 are respectively connected to the inlet of the cooler through an oil discharge pipe 8, and an oil discharge control valve 9 is installed on the oil discharge pipe 8; the bottom oil discharge port of the cooler is connected to the inlet of the recovery tank 3; the top material ports of the two adsorption towers 1 are respectively connected to a steam pipe through a regeneration pipe 10, and a regeneration control valve 11 is installed on the regeneration pipe 10; the top material ports of the two adsorption towers 1 are respectively connected to the cold medium inlet of the distillation column condenser 13 of the MTBE device through a tail gas pipe 12, and a tail gas control valve 14 is installed on the tail gas pipe 12; the cold medium outlet of the distillation column condenser 13 is connected to the air inlet of the turbo generator 4, and the exhaust port of the turbo generator 4 is connected to a vent pipe 15. The two adsorption towers 1 are in standby for each other. When one adsorption tower 1 is in adsorption, the other adsorption tower 1 is regenerated using steam, and the two adsorption towers 1 are switched with each other to facilitate continuous processing; taking the left adsorption tower 1 for adsorption as an example, it is necessary to close the corresponding feed control valve 7 and tail gas control valve 14, regeneration control valve 11 and oil discharge control valve 9 of the right adsorption tower 1, close the corresponding regeneration control valve 11 and oil discharge control valve 9 of the left adsorption tower 1, and open the corresponding feed control valve 7 and tail gas control valve 14 of the left adsorption tower 1. At this time, the tail gas discharged from the oil absorption tower 5 enters the left adsorption tower 1, and through the adsorbent bed layer of the activated carbon in the device, trace C6 and C7 components are adsorbed. The pressure of the adsorbed tail gas is 1.0 MPa, and the temperature is about 0 - 5 °C. First, it is sent to the distillation column condenser 13 of the MTBE device to provide cooling capacity for the distillation column condenser 13 of the MTBE device, and then it is sent to the turbo generator 4 for power generation to realize the utilization of the cooling capacity and pressure of the adsorbed tail gas, and finally it is discharged through the vent pipe 15. When the left adsorption tower 1 is saturated with adsorption, open the corresponding feed control valve 7 and tail gas control valve 14 of the right adsorption tower 1, open the corresponding regeneration control valve 11 and oil discharge control valve 9 of the left adsorption tower 1, and close the corresponding feed control valve 7 and tail gas control valve 14 of the left adsorption tower 1. Switch the right adsorption tower 1 to the adsorption state, switch out the left adsorption tower 1, and regenerate the left adsorption tower 1 using low-pressure steam. The absorbed oil discharged from the left adsorption tower 1 is cooled by the cooler and collected in the recovery tank 3 to realize the recovery of effective components.

[0012] The cooler includes a first cooler 2 and a second cooler 16. The outlet of the oil outlet pipe 8 is communicated with the inlet of the first cooler 2. The exhaust port of the first cooler 2 is communicated with the inlet of the second cooler 16. The oil discharge ports of the first cooler 2 and the second cooler 16 are both communicated with the inlet of the recovery tank 3. The exhaust port of the recovery tank 3 is communicated with the inlet of the second cooler 16. The absorption oil discharged from the regenerated adsorption tower 1 first enters the first cooler 2 for primary cooling. The gas discharged from the first cooler 2 is sent to the second cooler 16 for secondary cooling to further condense the absorption oil carried in the gas into the second cooler 16. The absorption oil discharged from the first cooler 2 and the second cooler 16 is all collected in the recovery tank 3. There is still a small amount of absorption oil carried in the exhaust air of the recovery tank 3. Therefore, it is sent to the inlet of the second cooler 16, and the second cooler 16 is used to further recover it, so as to improve the recovery rate of the absorption oil.

[0013] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tail gas recovery device for an oil absorption tower in a butadiene preparation system, characterized in that It includes an adsorption tower, a cooler, a recovery tank and a turbo generator. The tail gas discharge port at the top of the oil absorption tower is communicated with the bottom material ports of the two adsorption towers through a feed pipe, and a feed control valve is installed on the feed pipe; the bottom material ports of the two adsorption towers are respectively communicated with the inlet of the cooler through an oil discharge pipe, and an oil discharge control valve is installed on the oil discharge pipe; the bottom oil discharge port of the cooler is communicated with the inlet of the recovery tank; the top material ports of the two adsorption towers are respectively communicated with a steam pipe through a regeneration pipe, and a regeneration control valve is installed on the regeneration pipe; the top material ports of the two adsorption towers are respectively communicated with the cold medium inlet of the distillation column condenser of the MTBE unit through a tail gas pipe, and a tail gas control valve is installed on the tail gas pipe; the cold medium outlet of the distillation column condenser is communicated with the air inlet of the turbo generator, and an exhaust pipe is connected to the exhaust port of the turbo generator.

2. The tail gas recovery device of the oil absorption tower in the butadiene preparation system according to claim 1, wherein The cooler includes a first cooler and a second cooler. The outlet of the oil discharge pipe is communicated with the inlet of the first cooler. The exhaust port of the first cooler is communicated with the inlet of the second cooler. The oil discharge port of the first cooler and the oil discharge port of the second cooler are both communicated with the inlet of the recovery tank.

3. The tail gas recovery device of the oil absorption tower in the butadiene preparation system according to claim 2, characterized in that, The exhaust port of the recovery tank is communicated with the inlet of the second cooler.

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