A pressure swing adsorption separation device for purifying propylene

Abstract

The utility model belongs to gas separation and purification technical field, especially a kind of pressure swing adsorption separation device for purifying propylene, including adsorption unit, adsorption unit includes three parallel adsorption bed, one operation two standby, propylene raw gas tank outlet is communicated with each adsorption bed bottom inlet, each adsorption bed outlet is communicated after confluence with buffer tank inlet, buffer tank outlet is sequentially connected with compressor and propylene storage tank;Propylene raw gas tank outlet and each adsorption bed bottom inlet communicated each pipeline is equipped with three-way valve respectively, one outlet of each three-way valve is communicated with each adsorption bed bottom inlet, another outlet of each three-way valve is communicated after confluence with regenerative vacuum pump inlet.The utility model's adsorption bed production speed is fast, and continuous production can be realized by quick switching adsorption bed and vacuum regeneration technology, and process is simple and energy consumption is less, solve the problem of high energy consumption and material consumption of existing multistage rectification purification.

Description

Technical Field

[0001] This invention belongs to the field of gas separation and purification technology, and in particular relates to a pressure swing adsorption separation device for purifying propylene. Background Technology

[0002] Electronic-grade propylene is a key raw material for the high-end chemical and electronic semiconductor industries, and its purity directly affects the performance and reliability of downstream products. With the continuous development of advanced technologies, the purity requirements for propylene are becoming increasingly stringent. Common industrial-grade propylene is insufficient to meet these requirements, necessitating further purification.

[0003] Industrial-grade propylene typically has a purity between 99% and 99.9%, mainly containing propane impurities with the same number of carbon atoms. This does not meet the standards for electronic-grade propylene and requires further purification of the industrial feedstock gas. Currently, the main method for obtaining high-purity propylene is through multi-stage distillation in series, which is energy and material-intensive. Utility Model Content

[0004] In view of the problems and shortcomings of the existing technology, the purpose of this utility model is to provide a pressure swing adsorption separation device for purifying propylene.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a pressure swing adsorption (PSA) separation device for purifying propylene, comprising an adsorption unit with three adsorption beds connected in parallel, one in operation and two on standby. The outlet of the propylene feed gas tank is connected to the bottom inlet of each adsorption bed, and the outlets of each adsorption bed merge and are connected to the inlet of a buffer tank. The outlet of the buffer tank is sequentially connected to a compressor and a propylene storage tank. Each pipeline connecting the outlet of the propylene feed gas tank to the bottom inlet of each adsorption bed is equipped with a three-way valve. One outlet of each three-way valve is connected to the bottom inlet of each adsorption bed, and the other outlet of each three-way valve merges and is connected to the inlet of a regeneration vacuum pump.

[0006] Furthermore, the outlet of the regeneration vacuum pump is connected to an exhaust gas treatment device.

[0007] Furthermore, a flow meter is connected to the outlet of the propylene feedstock gas tank.

[0008] Furthermore, each adsorption bed in the adsorption unit is connected to a control valve at both its inlet and outlet.

[0009] Furthermore, each of the three-way valves is connected to a control valve before its other outlet merges.

[0010] Furthermore, a control valve is connected between the propylene feedstock gas tank and the flow meter.

[0011] Furthermore, the inlet of the buffer tank is connected to a control valve.

[0012] Furthermore, the three-way valve is located between the bottom inlet of each adsorption bed and the control valve connected thereto.

[0013] Furthermore, each adsorption bed in the adsorption unit is filled with 13X molecular sieve adsorbent or an adsorbent composed of nickel oxide, tungsten oxide, hydrogen fluoride, pyrazine, sodium alginate and calcium chloride.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: (1) The adsorption bed of this utility model has a fast production speed. Continuous production can be achieved by quickly switching the adsorption bed and vacuum regeneration technology. The process is simple and consumes less energy, which solves the problem of high energy consumption and material consumption in the existing multi-stage distillation purification.

[0015] (2) The pressure swing adsorption separation unit is modularly designed, and different separation purposes can be achieved by changing the type of adsorbent, which is highly adjustable. The obtained product gas can be used as electronic-grade propylene product gas that meets national standards, or as raw material gas for further purification, effectively reducing the theoretical plate number of subsequent distillation.

[0016] (3) The present invention provides a buffer tank after the adsorption bed, which can maintain the gas pressure in the pipeline and increase the reliability of the whole set of equipment under long-term operating conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the pressure swing adsorption separation device of Embodiment 1 of this utility model.

[0018] In the diagram: 1. Propylene feedstock gas tank; 2. Flow meter; 31, 32, 33 adsorption beds; 4. Buffer tank; 5. Compressor; 6. Propylene storage tank; 7. Vacuum pump for regeneration; 8. Tail gas treatment device. Detailed Implementation

[0019] The present invention will now be described in detail, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0020] Example 1: A schematic diagram of a pressure swing adsorption (PSA) separation device for propylene purification is shown below. Figure 1As shown, the system includes an adsorption unit comprising three parallel adsorption beds 31, 32, and 33, with one bed in operation and two on standby. Each adsorption bed 31, 32, and 33 is filled with adsorbent. Three layers of inert alumina ceramic balls are laid at the bottom of each adsorption bed for support; the middle layer consists of 1 / 8-inch ceramic balls, and the top and bottom layers consist of 1 / 4-inch ceramic balls. The outlet of the propylene feedstock gas tank 1 is connected to the bottom inlet of each adsorption bed 31, 32, and 33 via a flow meter 2. The outlets of all adsorption beds converge and connect to the inlet of a buffer tank 4. The outlet of the buffer tank 4 is sequentially connected to a compressor 5 and a propylene storage tank 6. Three-way valves are installed on the pipelines connecting the outlet of the propylene feedstock gas tank 1 to the bottom inlets of each adsorption bed. One outlet of each three-way valve connects to the bottom inlet of each adsorption bed, and the other outlet of each three-way valve converges and connects to the inlet of a regeneration vacuum pump 7. The outlet of the regeneration vacuum pump 7 connects to the inlet of a tail gas treatment device 8.

[0021] In the adsorption unit, the inlet and outlet of each adsorption bed 31, 32, and 33 are connected to control valves; each three-way valve is connected to a control valve before its other outlet merges; a control valve is connected between the propylene feed gas tank 1 and the flow meter 2; a control valve is connected to the inlet of the buffer tank 4; and a three-way valve is located between the bottom inlet of each adsorption bed and the control valve connected to it.

[0022] The adsorbent can be a commercially available 13X molecular sieve adsorbent, or a composite material formed by combining nickel oxide, tungsten oxide, hydrogen fluoride, pyrazine, sodium alginate and calcium chloride as the adsorbent.

[0023] The specific method for purifying propylene using the above-mentioned pressure swing adsorption separation device is as follows: (1) Fill each adsorption bed 31, 32 and 33 with 8 kg of adsorbent composed of nickel oxide, tungsten oxide, hydrogen fluoride, pyrazine, sodium alginate and calcium chloride, and then activate the adsorbent in the three adsorption beds: pass nitrogen into the above device to activate the adsorbent by hot nitrogen purging. The nitrogen flow rate is 5 L / min, the temperature is 100℃ and the purging time is 8 hours. (2) Open the propylene feed gas tank 1 and introduce the propane-propylene mixture (with the total molar amount of propane and propylene being 100%, the propylene content being 99.65%, and the total processing volume of the propane-propylene mixture and the mass ratio of the adsorbent during the adsorption process being 12:1) into the adsorption bed to be operated. The propane-propylene mixture is fed at room temperature, the inlet pressure is 0.12 MPaG, the flow rate of the flow meter 2 is controlled at 60 mL / min, the adsorption bed temperature is controlled at 30℃, and the pressure is controlled at 0.12 MPaG. The propane-propylene mixture stays in the adsorption bed for 1 minute, and the propane is adsorbed onto the adsorbent. After the adsorption continues for several hours, the propylene enters the buffer tank 4 and is transported to the propylene storage tank 6 by the compressor 5. During this process, the propane impurities will be removed to below 100 ppm. (3) After one adsorption bed has been running continuously for 48 hours, it is switched to a standby adsorption bed. The original adsorption bed is regenerated by vacuum pump 7 at a vacuum pressure of -0.099 MPaG, a regeneration temperature of 75℃, and a regeneration time of 12 minutes. The resulting tail gas is treated by tail gas treatment device 8. The adsorption bed can be switched at any time to ensure the continuous operation of the separation process. After the above treatment, the purity of the obtained propylene product gas is above 99.99%.

[0024] Although the description of this utility model has been given in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations should fall within the protection scope of the claims of this utility model.

Claims

1. A pressure swing adsorption separation device for purifying propylene, characterized in that, The system includes an adsorption unit, which consists of three adsorption beds connected in parallel, with one operating and two on standby. The outlet of the propylene feed gas tank is connected to the bottom inlet of each adsorption bed. The outlets of all adsorption beds merge and are connected to the inlet of a buffer tank. The outlet of the buffer tank is connected in sequence to a compressor and a propylene storage tank. Each pipeline connecting the outlet of the propylene feed gas tank to the bottom inlet of each adsorption bed is equipped with a three-way valve. One outlet of each three-way valve is connected to the bottom inlet of each adsorption bed, and the other outlet of each three-way valve merges and is connected to the inlet of a regeneration vacuum pump.

2. The pressure swing adsorption separation device for purifying propylene according to claim 1, characterized in that, The outlet of the regeneration vacuum pump is connected to an exhaust gas treatment device.

3. The pressure swing adsorption separation device for purifying propylene according to claim 1, characterized in that, A flow meter is connected to the outlet of the propylene feedstock gas tank.

4. The pressure swing adsorption separation device for purifying propylene according to claim 1, characterized in that, Each adsorption bed in the adsorption unit is connected to a control valve at both its inlet and outlet.

5. The pressure swing adsorption separation device for purifying propylene according to claim 1, characterized in that, Each of the three-way valves is connected to a control valve before its other outlet merges.

6. The pressure swing adsorption separation apparatus for purifying propylene according to claim 1 or 3, characterized in that, A control valve is connected between the propylene feedstock gas tank and the flow meter.

7. The pressure swing adsorption separation device for purifying propylene according to claim 1, characterized in that, The inlet of the buffer tank is connected to a control valve.

8. The pressure swing adsorption separation apparatus for purifying propylene according to claim 1 or 4, characterized in that, The three-way valve is located between the bottom inlet of each adsorption bed and the control valve connected thereto.

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