Pressure swing adsorption purification and recovery device and process for polypropylene SPG process tail gas

Abstract

The invention relates to the technical field of tail gas treatment, in particular to a pressure swing adsorption purification and recovery device and process for polypropylene SPG process tail gas. The pressure swing adsorption purification and recovery device for polypropylene SPG process tail gas comprises a recovered gas buffer tank, a folded wave filter, a compressor, a refrigeration dryer, athree-stage precision filter, a separator and a pressure swing adsorption tower which are connected in sequence. The recovered gas buffer tank is connected with a polypropylene SPG process tail gas pipeline. The top of the pressure swing adsorption tower is connected with a nitrogen buffer tank through a nitrogen discharge pipeline and is also connected with a flushing gas buffer tank through a sequential discharge pipeline. The bottom of the pressure swing adsorption tower is connected with a gas inlet pipeline and a reverse discharge pipeline. According to the device and process, the pressure swing adsorption technology is adopted for purifying the polypropylene SPG process tail gas, nitrogen in the tail gas is recycled while organic gas such as propylene and propane is removed, the emission environmental protection problem is solved, and benefits are increased for enterprises.

Description

technical field

[0001] The invention relates to the technical field of tail gas treatment, in particular to a pressure swing adsorption purification and recovery device and process for the tail gas of a polypropylene SPG process. Background technique

[0002] In the SPG continuous polypropylene process, PP powder is contacted with nitrogen at about 100°C in a dryer to separate traces of volatile components such as propylene and propane, and at the same time deactivate the catalyst. The separated nitrogen contains VOCs gases such as propylene, propane and ethylene. The concentration of organic matter in this part of the gas is very low and cannot be burned independently, so it cannot be discharged through torch combustion; but the concentration is far beyond the national VOCs gas emission standard, so it must be treated before it can be discharged.

[0003] Patent CN201811610062.9 discloses a process and device for purifying and recovering polypropylene tail gas by pressure ...

Examples

Embodiment 1

[0045] Such as figure 1As shown, a pressure swing adsorption purification and recovery device for polypropylene SPG process tail gas of the present invention includes a recovery gas buffer tank 3, a folded wave filter 4, a compressor 8, a cold dryer 9, and three-stage precision filtration successively connected device 11, separator 12 and pressure swing adsorption tower 15; the recovery gas buffer tank 3 is connected with polypropylene SPG process tail gas pipeline 1; the top of the pressure swing adsorption tower 15 is connected to the nitrogen buffer tank 20 through a nitrogen discharge pipeline 25 , the nitrogen buffer tank 20 is connected with a nitrogen recycling pipeline 21; the top of the pressure swing adsorption tower 15 is also connected with the flushing gas buffer tank 23 through a parallel release pipeline 24; the bottom of the pressure swing adsorption tower 14 is connected with an inlet pipeline 14 and a Drain line 17.

[0046] The polypropylene SPG tail gas pi...

Embodiment 2

[0058] The pressure swing adsorption purification and recovery device of the polypropylene SPG process tail gas of Example 1 is used to treat the tail gas of the 300,000 tons / year SPG process polypropylene enterprise, the tail gas temperature is 35 ° C, the pressure is 1.5KPa (g), and the flow rate is 1500Nm 3 / h (dry gas), in mol percentage, tail gas component analysis is as follows:

[0059] name Acrylic propane Nitrogen n-butane ethane water vapor C6+ Isopentane Content, %mol 2.46 1.044 96.457 0.001 0.034 saturation 0.02 0.001

[0060] The specific process steps are as follows:

[0061] After the tail gas of the polypropylene SPG process is stabilized by the recovery gas buffer tank 3, it is filtered through the folding filter 4 in turn, pressurized to 0.5-0.8 MPa through the compressor 8 (adjusted according to the pressure requirements of nitrogen reuse), and then passed through the cold The drying machine 9 performs cooling and ...

technical field

[0001] The invention relates to the technical field of tail gas treatment, in particular to a pressure swing adsorption purification and recovery device and process for the tail gas of a polypropylene SPG process. Background technique

[0002] In the SPG continuous polypropylene process, PP powder is contacted with nitrogen at about 100°C in a dryer to separate traces of volatile components such as propylene and propane, and at the same time deactivate the catalyst. The separated nitrogen contains VOCs gases such as propylene, propane and ethylene. The concentration of organic matter in this part of the gas is very low and cannot be burned independently, so it cannot be discharged through torch combustion; but the concentration is far beyond the national VOCs gas emission standard, so it must be treated before it can be discharged.

[0003] Patent CN201811610062.9 discloses a process and device for purifying and recovering polypropylene tail gas by pressure ...

Examples

Embodiment 1

[0045] Such as figure 1As shown, a pressure swing adsorption purification and recovery device for polypropylene SPG process tail gas of the present invention includes a recovery gas buffer tank 3, a folded wave filter 4, a compressor 8, a cold dryer 9, and three-stage precision filtration successively connected device 11, separator 12 and pressure swing adsorption tower 15; the recovery gas buffer tank 3 is connected with polypropylene SPG process tail gas pipeline 1; the top of the pressure swing adsorption tower 15 is connected to the nitrogen buffer tank 20 through a nitrogen discharge pipeline 25 , the nitrogen buffer tank 20 is connected with a nitrogen recycling pipeline 21; the top of the pressure swing adsorption tower 15 is also connected with the flushing gas buffer tank 23 through a parallel release pipeline 24; the bottom of the pressure swing adsorption tower 14 is connected with an inlet pipeline 14 and a Drain line 17.

[0046] The polypropylene SPG tail gas pi...

Embodiment 2

[0058] The pressure swing adsorption purification and recovery device of the polypropylene SPG process tail gas of Example 1 is used to treat the tail gas of the 300,000 tons / year SPG process polypropylene enterprise, the tail gas temperature is 35 ° C, the pressure is 1.5KPa (g), and the flow rate is 1500Nm 3 / h (dry gas), in mol percentage, tail gas component analysis is as follows:

[0059] name Acrylic propane Nitrogen n-butane ethane water vapor C6+ Isopentane Content, %mol 2.46 1.044 96.457 0.001 0.034 saturation 0.02 0.001

[0060] The specific process steps are as follows:

[0061] After the tail gas of the polypropylene SPG process is stabilized by the recovery gas buffer tank 3, it is filtered through the folding filter 4 in turn, pressurized to 0.5-0.8 MPa through the compressor 8 (adjusted according to the pressure requirements of nitrogen reuse), and then passed through the cold The drying machine 9 performs cooling and ...

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