Membrane method gas separation method and system, computer storage medium and terminal

Abstract

The invention discloses a membrane method gas separation method and system, a computer storage medium and a terminal. The membrane method gas separation method comprises the following steps: adjusting the vacuum degree of a permeation side to a predetermined vacuum degree target value; when judging that the permeation side reaches the vacuum degree target value, carrying out separation and concentration treatment on the permeation gas; wherein the target value of the vacuum degree is greater than a preset minimum value of the vacuum degree. According to the embodiment of the invention, the treatment of vacuumizing to the vacuum degree target value is carried out on the permeation side, so that the pressure difference of the two sides of the membrane module is increased, the pressure ratio of the two sides of the membrane module is increased, and the membrane-method gas separation effect is improved.

Description

Technical Field

[0001] The present application relates to but is not limited to gas processing technology, and particularly to a membrane gas separation method, system, computer storage medium and terminal. Background Art

[0002] In recent years, membrane gas separation has been gradually applied to the field of natural gas processing and processing, showing good application prospects. Membrane gas separation uses the difference in the rate at which different gas components pass through the membrane assembly (gas separation membrane rate) driven by pressure difference to achieve gas separation; taking helium extraction as an example, high-pressure helium-containing natural gas enters the membrane assembly as the raw gas, and helium is a "fast gas" that can pass through the membrane material at high speed to become a low-pressure product gas (permeate gas); other gases such as methane are "slow gases" and are enriched on the high-pressure retentate side (tail gas). Membrane gas separation can achieve natural gas dehydration, desulfurization (or decarbonization), condensate recovery, natural gas helium extraction and other processing processes at room temperature. The entire process does not require heating and has the advantages of simple process, small equipment footprint and low operating costs; however, the effect of gas separation and concentration using membrane gas separation in related technologies is poor. How to improve the effect of membrane gas separation has become a problem to be solved. Summary of the invention

[0003] The following is a summary of the subject matter described in detail in this application. This summary is not intended to limit the scope of the claims.

[0004] The embodiments of the present disclosure provide a membrane gas separation method, system, computer storage medium and terminal, which can improve the effect of membrane gas separation.

[0005] The present disclosure provides a membrane gas separation method, comprising:

[0006] Adjusting the vacuum degree on the permeate side to a predetermined vacuum degree target value;

[0007] When it is determined that the vacuum degree target value is reached on the permeate side, the permeate gas is separated and concentrated; wherein the vacuum degree target value is greater than a preset vacuum degree minimum value.

[0008] On the other hand, an embodiment of the present disclosure further provides a computer storage medium, in which a computer program is stored. When the computer program is executed by a processor, the above-mentioned membrane gas separation method is implemented.

[0009] In another aspect, an embodiment of the present disclosure further provides a terminal, comprising: a memory and a processor, wherein the memory stores a computer program; wherein:

[0010] The processor is configured to execute the computer program in the memory;

[0011] When the computer program is executed by the processor, the membrane gas separation method as described above is implemented.

[0012] In another aspect, the present disclosure also provides a membrane gas separation system, comprising:

[0013] The control device is configured to: adjust the vacuum degree on the permeate side to a predetermined vacuum degree target value;

[0014] The gas processing device is configured to separate and concentrate the permeated gas to obtain product gas when the vacuum degree on the permeate side reaches the target value;

[0015] Wherein, the vacuum degree target value is greater than a preset vacuum degree minimum value.

[0016] Compared with the related art, the present application includes: adjusting the vacuum degree on the permeate side to a predetermined vacuum degree target value; when it is determined that the vacuum degree on the permeate side reaches the vacuum degree target value, performing separation and concentration processing on the permeate gas. The disclosed embodiment increases the pressure difference on both sides of the membrane assembly and the pressure ratio on both sides of the membrane assembly by evacuating the permeate side to the vacuum degree target value, thereby improving the effect of membrane gas separation.

[0017] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0019] Figure 1 This is a flow chart of the membrane gas separation method according to an embodiment of the present disclosure;

[0020] Figure 2 It is a structural block diagram of a membrane gas separation device according to an embodiment of the present disclosure;

[0021] Figure 3 A membrane gas separation system for gas separation and concentration according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0023] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0024] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0025] During the membrane gas separation process, the driving force for gas to pass through the membrane assembly is the pressure difference of the gas components on the feed side and the permeate side. Currently, the main method used in engineering is to increase the pressure on the feed side by using a feed gas compressor to increase the pressure difference on both sides of the membrane assembly. In fact, the pressure ratio between the feed side and the permeate side is an important factor affecting the rate and effect of membrane gas separation; although increasing the feed gas pressure by using a feed gas compressor can significantly increase the pressure difference on both sides of the membrane assembly, the effect of increasing the pressure ratio is not obvious, which limits the effect of membrane gas separation to a certain extent.

[0026] In order to solve the problem that increasing the raw gas pressure can increase the pressure difference on both sides of the membrane, but the effect of increasing the pressure ratio is not obvious, the disclosed embodiment proposes a technical solution of adding a permeate gas vacuum pump on the permeate side to draw a vacuum.

[0027] Figure 1 Flow chart of the membrane gas separation method according to the embodiment of the present disclosure, as shown in Figure 1 As shown, including:

[0028] Step 101, adjusting the vacuum degree on the permeate side to a predetermined vacuum degree target value;

[0029] Step 102: when it is determined that the vacuum degree on the permeate side reaches the target value, the permeate gas is separated and concentrated; here, after the permeate gas is separated and concentrated, the product gas can be obtained by referring to the relevant technology;

[0030] The vacuum target value is greater than a preset vacuum minimum value.

[0031] The embodiment of the present disclosure increases the pressure difference on both sides of the membrane assembly and the pressure ratio on both sides of the membrane assembly by evacuating the permeate side to a target vacuum value, thereby improving the membrane gas separation effect.

[0032] In the membrane gas separation method of the embodiment of the present disclosure, the permeate side and the feed side are separated by a membrane assembly, and the membrane assembly is the core device for realizing gas separation; the types of membrane assemblies in the embodiment of the present disclosure may include hollow fiber membranes, rolled membranes, flat membranes or tubular membranes.

[0033] The vacuum target value of the embodiment of the present disclosure can be set by technical personnel based on experience according to the application scenario of membrane gas separation. By setting a reasonable vacuum target value, the pressure difference on both sides of the membrane assembly can be increased, and the pressure ratio can be greatly increased, thereby improving the membrane separation efficiency and providing a raw material basis for other subsequent processing. In an exemplary embodiment, the vacuum target value in the embodiment of the present disclosure can be a value in the range of 1-100 kilopascals (kPa); the vacuum target value of the embodiment of the present disclosure can be a value in the range of 10 kPa to 80 kPa.

[0034] In an exemplary embodiment, the vacuum degree target value of the embodiment of the present disclosure is determined by the following process:

[0035] Obtaining pressure data and composition data of the raw gas and pressure data and composition data of the permeate gas;

[0036] The vacuum degree target value is calculated based on the obtained pressure data and composition data of the raw gas, the pressure data and composition data of the permeate gas and the predetermined membrane separation parameters.

[0037] The basic principle of calculating the target vacuum value in the embodiment of the present disclosure is: the permeation rate differential equation dRi=JidA△pi, wherein Ri is the permeation rate of component i per unit area, Ji is the permeability coefficient of component i, A is the membrane area, and △pi is the partial pressure difference between the raw gas of component i and the permeating gas, which is the driving force for gas to permeate the membrane material.

[0038] Based on the above calculations, the disclosed embodiments can accurately obtain an objective vacuum target value that meets production applications, and provide data support for objectively and accurately improving the pressure difference and pressure ratio on both sides of the membrane assembly, improving the membrane separation efficiency and the quality of gas separation and concentration. The vacuum target value obtained by calculation can ensure that the final product gas produces a membrane separation effect that meets user requirements.

[0039] In an exemplary embodiment, the embodiment of the present disclosure obtains pressure data and composition data of the raw gas and pressure data and composition data of the permeate gas, including:

[0040] The pressure data and composition data of the raw gas are obtained by means of a pressure gauge and an online component analyzer installed at the inlet pipeline of the membrane module;

[0041] The pressure data and composition data of the permeate gas are obtained by setting up a pressure gauge and an online component analyzer at the outlet pipeline of the membrane module.

[0042] It should be noted that the embodiments of the present disclosure may adopt other sensors or methods with reference to relevant technologies to obtain the above-mentioned pressure data and composition data, and the embodiments of the present disclosure are not limited to this.

[0043] In an exemplary embodiment, the membrane separation parameters in the embodiments of the present disclosure may include:

[0044] Gas permeability coefficient, membrane area and concentration target parameters;

[0045] The target parameters for concentration include the concentration multiple or the yield.

[0046] The membrane area and gas permeability coefficient of the disclosed embodiment can be obtained according to the factory parameters of the membrane assembly, and the concentration multiple or yield can be determined by the technician according to the requirements of gas separation and concentration. The concentration multiple is the ratio of the target product gas concentration in the permeate gas to the target product gas concentration in the feed gas, and the yield is the ratio of the molar flow rate of the target product gas in the permeate gas to the molar flow rate of the target product gas in the feed gas; for a specific membrane separation system, the concentration multiple and the yield are coupled to each other, and the user only needs to set one of them.

[0047] In an exemplary embodiment, when determining the membrane separation parameters, the above-mentioned calculation of the vacuum target value and the adjustment of the vacuum degree on the permeate side in the embodiment of the present disclosure can be automatically completed by an automatic control system. By automatically adjusting the vacuum degree target on the permeate side online, while meeting the user's gas separation and concentration needs, it can also adapt to fluctuations in the raw gas composition.

[0048] In an exemplary embodiment, the vacuum target value of the permeate side of the embodiment of the present disclosure is calculated and determined by the following formula:

[0049] F·x i =S·y i +W·z i

[0050] S.x i =J i ·(p I ·x i -p e ·y i )A

[0051] p v =103.15-p e

[0052] Where n is the total number of gas components in the raw gas, F is the raw gas flow rate, x i is the mole fraction of the i-th gas component in the feed gas, The raw gas flow rate and the molar fraction of each gas component in the raw gas are the raw gas component data; S is the permeate flow rate, y i is the mole fraction of the i-th gas component in the permeate gas, The permeate gas flow rate and the molar fraction of each gas component in the permeate gas are the permeate gas component data; W is the tail gas flow rate, which is determined according to the feed gas flow rate and the permeate gas flow rate; i is the mole fraction of the i-th gas component in the exhaust gas, The mole fraction of the i-th gas component in the tail gas is determined according to the mole fraction of the i-th gas component in the feed gas and the mole fraction of the i-th gas component in the permeate gas; I is the pressure data of the raw gas (pressure inside the membrane), p e is the pressure data of permeate gas (external pressure of membrane); J i is the gas permeability coefficient of the i-th gas component, A is the membrane area, p v When the vacuum degree is the concentration target parameter and the concentration multiple is the concentration multiple, the concentration multiple of the i-th gas is recorded as K i , When the target parameter of enrichment is yield, the yield of the i-th gas is recorded as Y i ,

[0053] In an exemplary embodiment, the embodiment of the present disclosure adjusts the vacuum degree of the permeate side to a predetermined vacuum degree target value, including:

[0054] The vacuum degree on the permeate side is adjusted to the target vacuum degree value by controlling the power of the vacuum pump pre-set in the outlet pipeline on the permeate side.

[0055] In an exemplary embodiment, the vacuum pump in the embodiment of the present disclosure may include any one of the following types: liquid ring vacuum pump, reciprocating vacuum pump, rotary vane vacuum pump, fixed vane vacuum pump, sliding valve vacuum pump, trochoid vacuum pump, dry vacuum pump, Roots vacuum pump, molecular vacuum pump, drag molecular pump, compound vacuum pump, water jet vacuum pump, etc. In the embodiment of the present disclosure, the technicians can select the vacuum pump according to the application scenario, and the implementation of power control can be set and adjusted by the technicians.

[0056] The embodiment of the present disclosure also provides a computer storage medium, in which a computer program is stored. When the computer program is executed by a processor, the above-mentioned membrane gas separation method is implemented.

[0057] The embodiment of the present disclosure further provides a terminal, comprising: a memory and a processor, wherein a computer program is stored in the memory;

[0058] The processor is configured to execute the computer program in the memory;

[0059] When the computer program is executed by a processor, the above-mentioned membrane gas separation method is implemented.

[0060] Figure 2 is a structural block diagram of a membrane gas separation system according to an embodiment of the present disclosure, such as Figure 2 As shown, it includes: a control device and a gas processing device; wherein,

[0061] The control device is configured to: adjust the vacuum degree on the permeate side to a predetermined vacuum degree target value;

[0062] The gas treatment device is configured to separate and concentrate the permeated gas when the vacuum degree on the permeate side reaches the target value;

[0063] The vacuum target value is greater than a preset vacuum minimum value.

[0064] The embodiment of the present disclosure increases the pressure difference on both sides of the membrane assembly and the pressure ratio on both sides of the membrane assembly by evacuating the permeate side to a target vacuum value, thereby improving the membrane gas separation effect.

[0065] The vacuum target value of the embodiment of the present disclosure can be set by technical personnel based on experience according to the application scenario of membrane gas separation. By setting a reasonable vacuum target value, the pressure difference on both sides of the membrane assembly can be increased, and the pressure ratio can be greatly increased, thereby improving the membrane separation efficiency and providing a raw material basis for other subsequent processing. In an exemplary embodiment, the vacuum target value in the embodiment of the present disclosure can be a value in the range of 1-100 kilopascals (kPa); the vacuum target value of the embodiment of the present disclosure can be a value in the range of 10 kPa to 80 kPa.

[0066] In an exemplary embodiment, the system of the embodiment of the present disclosure further includes a monitoring processing device, which is configured to:

[0067] Obtaining pressure data and composition data of the raw gas and pressure data and composition data of the permeate gas;

[0068] The vacuum degree target value is calculated based on the obtained pressure data and composition data of the raw gas, the pressure data and composition data of the permeate gas and the predetermined membrane separation parameters.

[0069] The basic principle of calculating the vacuum target value in the disclosed embodiment is: the permeation rate differential equation dRi = JidA△pi, where Ri is the permeation rate of component i per unit area, Ji is the permeability coefficient of component i, A is the membrane area, and △pi is the partial pressure difference between the raw gas of component i and the permeate gas, which is the driving force for the gas to permeate the membrane material. Based on the above calculation, the disclosed embodiment can accurately obtain an objective vacuum target value that meets production applications, and provide data support for objectively and accurately improving the pressure difference and pressure ratio on both sides of the membrane assembly, improving the membrane separation efficiency and the quality of gas separation and concentration. The vacuum target value obtained by calculation can make the final product gas meet the membrane separation effect required by users.

[0070] In an exemplary embodiment, the monitoring and processing device in the embodiment of the present disclosure includes: a pressure gauge and an online component analyzer arranged at the inlet pipeline of the membrane module and a pressure gauge and an online component analyzer arranged at the outlet pipeline of the membrane module; wherein,

[0071] The pressure gauge and online component analyzer installed at the inlet pipeline of the membrane module are set to: obtain the pressure data and composition data of the raw gas;

[0072] The pressure gauge and the online component analyzer installed in the outlet pipeline of the membrane module are set to obtain the pressure data and composition data of the permeated gas.

[0073] In an exemplary embodiment, the membrane separation parameters in the embodiments of the present disclosure include:

[0074] Gas permeability coefficient, membrane area and concentration target parameters;

[0075] The target parameters for concentration include the concentration multiple or the yield.

[0076] The membrane area and gas permeability coefficient of the disclosed embodiment can be obtained according to the factory parameters of the membrane assembly, and the concentration multiple or yield can be determined by the technician according to the requirements of gas separation and concentration. The concentration multiple is the ratio of the target product gas concentration in the permeate gas to the target product gas concentration in the feed gas, and the yield is the ratio of the molar flow rate of the target product gas in the permeate gas to the molar flow rate of the target product gas in the feed gas; for a specific membrane separation system, the concentration multiple and the yield are coupled to each other, and the user only needs to set one of them.

[0077] In an exemplary embodiment, when determining the membrane separation parameters, the above-mentioned calculation of the vacuum target value and the adjustment of the vacuum degree on the permeate side in the embodiment of the present disclosure can be automatically completed by an automatic control system. By automatically adjusting the vacuum degree target on the permeate side online, while meeting the user's gas separation and concentration needs, it can also adapt to fluctuations in the raw gas composition.

[0078] In an exemplary embodiment, the monitoring and processing device in the embodiment of the present disclosure calculates and determines the vacuum degree target value by the following formula:

[0079] F·x i =S·y i +W·z i

[0080] S.x i =J i ·(p I ·x i -p e ·y i )A

[0081] p v =103.15-p e

[0082] Where n is the total number of gas components in the raw gas, F is the raw gas flow rate, x i is the mole fraction of the i-th gas component in the feed gas, The raw gas flow rate and the molar fraction of each gas component in the raw gas are the raw gas component data; S is the permeate flow rate, y i is the mole fraction of the i-th gas component in the permeate gas, The permeate gas flow rate and the molar fraction of each gas component in the permeate gas are the permeate gas component data; W is the tail gas flow rate, which is determined according to the feed gas flow rate and the permeate gas flow rate; i is the mole fraction of the i-th gas component in the exhaust gas, The tail gas flow rate is determined according to the feed gas flow rate and the permeate gas flow rate; iis the mole fraction of the i-th gas component in the tail gas, which is determined according to the mole fraction of the i-th gas component in the feed gas and the mole fraction of the i-th gas component in the permeate gas; p I is the pressure data of the raw gas (pressure inside the membrane), p e is the pressure data of permeate gas (external pressure of membrane); J i is the gas permeability coefficient of the i-th gas component, A is the membrane area, p v is the vacuum degree; when the target parameter of enrichment is the enrichment multiple, the enrichment multiple of the i-th gas is recorded as K i , When the target parameter of enrichment is yield, the yield of the i-th gas is recorded as Y i ,

[0083] In an exemplary embodiment, the control device of the embodiment of the present disclosure includes a vacuum pump pre-set in the permeate outlet pipeline, which is configured as follows:

[0084] By controlling the power of the vacuum pump, the vacuum degree on the permeate side is adjusted to the vacuum target value.

[0085] In an exemplary embodiment, the vacuum pump in the embodiment of the present disclosure may include any one of the following types: liquid ring vacuum pump, reciprocating vacuum pump, rotary vane vacuum pump, fixed vane vacuum pump, sliding valve vacuum pump, trochoid vacuum pump, dry vacuum pump, Roots vacuum pump, molecular vacuum pump, drag molecular pump, compound vacuum pump, water jet vacuum pump, etc. In the embodiment of the present disclosure, the technicians can select the vacuum pump according to the application scenario, and the implementation of power control can be set and adjusted by the technicians.

[0086] The following briefly describes the embodiments of the present disclosure through application examples. The application examples are only used to illustrate the embodiments of the present disclosure and are not used to limit the protection scope of the embodiments of the present disclosure.

[0087] Application Examples

[0088] Figure 3 The membrane gas separation system for gas separation and concentration according to the embodiment of the present disclosure includes a monitoring and processing device, a control device and a gas processing device. The monitoring and processing device and the control device are connected to the gas processing device, and the monitoring and processing device is connected to the control device; wherein,

[0089] The monitoring and processing device is configured to collect monitoring data during the separation and concentration process, and calculate the vacuum target value on the permeate side according to the collected monitoring data; the monitoring data includes: pressure data and composition data of the feed gas and pressure data and composition data of the permeate gas;

[0090] The control device is configured to: adjust the vacuum degree on the permeate side to a predetermined vacuum degree target value;

[0091] The gas processing device is configured to separate and concentrate the permeated gas to obtain product gas when the vacuum degree on the permeate side reaches the target value;

[0092] The embodiment of the present disclosure also receives predetermined membrane separation parameters through the monitoring and processing device, and is configured as follows: a vacuum target value is calculated based on the acquired monitoring data and membrane separation parameters; a control device adjusts the vacuum degree on the permeate side according to the vacuum target value; and the gas processing device is configured as follows: when the vacuum degree target value is reached on the permeate side, the permeate gas is separated and concentrated. The embodiment of the present disclosure can not only improve the membrane separation efficiency, but also facilitate the automation of membrane separation technology, save labor costs, and improve work efficiency.

[0093] In an exemplary embodiment, the monitoring and processing device includes: a pressure gauge 1-1 and an online component analyzer 1-2 arranged at the inlet pipeline of the membrane module, and a pressure gauge 1-3 and an online component analyzer 1-4 arranged at the outlet pipeline of the membrane module; the pressure gauge 1-1, the online component analyzer 1-2, the pressure gauge 1-3 and the online component analyzer 1-4 are all connected to the gas processing device, wherein the pressure gauge 1-1 and the pressure gauge 1-3 are respectively used to obtain the pressure data of the raw gas and the pressure data of the permeate gas; the online component analyzer 1-2 and the online component analyzer 1-4 are respectively used to obtain the composition data of the raw gas and the composition data of the permeate gas. The pressure gauge 1-1, the pressure gauge 1-3, the online component analyzer 1-2 and the online component analyzer 1-4 of the embodiment of the present disclosure are all connected to the control device, and can be connected to the control device through a data transmission line.

[0094] The gas processing device of the embodiment of the present disclosure includes a raw gas compressor 2-1, a membrane component 2-2, a permeate gas vacuum pump 2-3 (a vacuum pump arranged in the outlet pipeline on the permeate side in the embodiment of the present disclosure) and a product gas compressor 2-4 which are connected in sequence, wherein the raw gas compressor 2-1 pressurizes the input raw gas to obtain pressurized raw gas, and the pressurized raw gas enters the membrane component 2-2 for gas separation to obtain permeate gas and tail gas (residue gas), and the tail gas is discharged through the tail gas outlet of the membrane component 2-2, and the permeate gas obtained after separation enters the permeate gas vacuum pump 2-3 for vacuum treatment, and then enters the product gas compressor 2-4 for pressurization and output; the permeate gas vacuum pump can both increase the pressure difference on both sides of the membrane and greatly increase the pressure ratio, which can significantly improve the membrane separation efficiency.

[0095] In an illustrative example, the raw gas of the embodiment of the present disclosure enters the membrane gas separation system through the raw gas inlet, and the raw gas compressor 2-1, the membrane assembly 2-2, the permeate gas vacuum pump 2-3, and the product gas compressor 2-4 are connected in sequence through independent pipelines. The inlet pipeline pressure gauge 1-1 and the online component analyzer 1-2 of the membrane assembly 2-2, and the outlet pipeline is provided with a pressure gauge 1-3 and an online component analyzer 1-4; the control device is configured with a user interface and a control terminal, and the user interface is mainly provided for the user to set the required membrane separation parameters, including the concentration multiple, the yield and the vacuum target value. According to the monitoring data obtained by the online monitoring of the pressure gauge and the online analyzer, combined with the membrane separation parameters set by the user, the vacuum target value required on the permeate side can be calculated; according to the calculated vacuum target value, the permeate gas vacuum pump 2-3 is controlled by the control device, and the optimal pressure difference is generated on both sides of the membrane assembly by adjusting the vacuum degree on the permeate side to obtain the target product gas, so as to meet the membrane separation effect required by the user. The control device of the embodiment of the present disclosure is connected to the permeate gas vacuum pump 2-3 through a data transmission line.

[0096] The raw gas compressor 2-1 in the embodiment of the present disclosure can be a reciprocating compressor, a centrifugal compressor, a rotary compressor, an axial flow compressor or a mixed flow compressor; the membrane assembly 2-2 can be a central control fiber membrane, a roll membrane, a flat membrane or a tubular membrane; the permeate gas vacuum pump 2-3 can be a liquid ring vacuum pump, a reciprocating vacuum pump, a rotary vane vacuum pump, a fixed vane vacuum pump, a sliding valve vacuum pump, a trochoid vacuum pump, a dry vacuum pump, a Roots vacuum pump, a molecular vacuum pump, a traction molecular pump, a compound vacuum pump or a water jet vacuum pump; the product gas compressor 2-4 can be a reciprocating compressor, a centrifugal compressor, a rotary compressor, an axial flow compressor or a mixed flow compressor.

[0097] In an exemplary embodiment, the embodiment of the present disclosure can set the inlet pressure of the membrane component 2-2 to 0.5-8 megapascals (Mpa), the outlet pressure of the product gas compressor 2-4 to 0.5-8Mpa, the vacuum degree of the permeate gas vacuum pump 2-3 to 0-100kPa, the raw gas compressor 2-1 to have a range of 0.5-8MPa and an accuracy of 0.01MPa, the pressure gauge on the outlet pipeline of the membrane component 2-2 to have a range of vacuum degree of 1-100kPa and an accuracy of 0.1kPa, and the accuracy of the online component analyzer to the ppb level; through the above settings, the membrane separation effect can be further improved.

[0098] The following is an example of gas separation and concentration to illustrate the embodiments of the present disclosure:

[0099] Example 1: Helium Extraction

[0100] The raw gas with 1% helium content was input into the membrane gas separation system. The raw gas composition is shown in Table 1. The raw gas flow rate is 2000 Nm3 / h), after being pressurized to 2MPa by the raw gas compressor 2-1, it enters the membrane assembly 2-2 for gas separation, and the area of ​​the membrane assembly 2-2 is 450 square meters; when the permeation side is not evacuated (the vacuum target value is 0kPa), the helium content in the permeate gas is 10.8%, that is, the concentration multiple is 10.8 times, and the yield is 53.7%; when the vacuum target value is set to 10kPa, the helium content in the permeate gas is 16.2%, that is, the concentration multiple is 16.2 times, and the yield can reach 91.6%; when the vacuum is set to 100kPa, the helium content in the permeate gas is 16.7%, that is, the concentration multiple is 16.7 times, and the yield reaches 95.4%. It can be seen that after setting the vacuum target value of the permeate gas vacuum pump 2-3, the concentration multiple and the yield can be greatly improved.

[0101] name Molar content He 0.010000 CH4 0.978591 C2H6 0.002553 C3H8 0.000008 CO2 0.004128 N2 0.004548 H2 0.000172

[0102] Table 1

[0103] Example 2: Carbon capture

[0104] The raw gas with a carbon dioxide content of 8% enters the membrane gas separation system. The composition of the raw gas is shown in Table 2. The raw gas flow rate is 2000Nm 3 / h, after being pressurized to 2MPa by the raw gas compressor 2-1, it enters the membrane component 2-2 for gas separation. The area of ​​the membrane component 2-2 is 450 square meters; when the yield is set to 50.0%, the vacuum degree is 0kPa, and the vacuum pump is not started. At this time, the carbon dioxide content in the permeate gas is 36.7%, that is, the concentration multiple is 4.6 times; when the yield is set to 60.0%, the required vacuum target value is calculated to be 77kPa, and the permeate gas vacuum pump 2-3 automatically starts to ensure the vacuum degree on the permeate side. At this time, the carbon dioxide content in the permeate gas is 39.8%, that is, the concentration multiple is 5.0 times.

[0105] name Molar content CO2 0.08000 O2 0.10700 CO 0.00030 NO 0.00020 SO2 0.00005 N2 0.81145 NO2 0.00100

[0106] Table 2

[0107] Example 3: Sulfur Recovery

[0108] The raw gas with a sulfur dioxide content of 1% enters the membrane gas separation system. The composition of the raw gas is shown in Table 3. The raw gas flow rate is 2000Nm 3 / h, after being pressurized to 3MPa by the raw gas compressor 2-1, it enters the membrane component 2-2 for gas separation. The area of ​​the membrane component 2-2 is 450 square meters. When the yield is set to 60.0%, the required vacuum target value is calculated to be 50kPa, and the permeate gas vacuum pump 2-3 automatically starts to ensure the vacuum degree on the permeate side. At this time, the sulfur dioxide content in the permeate gas is 7.0%, that is, the concentration multiple is 7.0 times; when the sulfur dioxide content in the raw gas fluctuates to 5%, the required vacuum target value is calculated to be 32kPa, and the permeate gas vacuum pump 2-3 automatically adjusts the permeate side pressure to 32kPa, and the yield can still be maintained at 60.0%.

[0109] name Molar content (before fluctuation) Molar content (after fluctuation) CO2 0.00002 0.00002 O2 0.00107 0.00107 CO 0.00003 0.00003 NO 0.00002 0.00002 SO2 0.01000 0.05000 N2 0.98885 0.94885 NO2 0.00001 0.00001

[0110] Table 3

[0111] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A membrane gas separation method, characterized in that: include: Adjusting the vacuum degree on the permeate side to a predetermined vacuum degree target value; When it is determined that the vacuum degree on the permeate side reaches the target value, the permeate gas is separated and concentrated; Wherein, the vacuum degree target value is greater than a preset vacuum degree minimum value.

2. The method according to claim 1, characterized in that The target vacuum degree is a value between 10 kPa and 80 kPa.

3. The method according to claim 1, characterized in that The vacuum target value is determined by the following process: Obtaining pressure data and composition data of the raw gas and pressure data and composition data of the permeate gas; The vacuum degree target value is calculated based on the acquired pressure data and composition data of the feed gas, the pressure data and composition data of the permeate gas, and predetermined membrane separation parameters.

4. The method according to claim 3, characterized in that The step of obtaining the pressure data and composition data of the raw gas and the pressure data and composition data of the permeate gas includes: Obtaining the pressure data and composition data of the raw gas through a pressure gauge and an online component analyzer arranged at the inlet pipeline of the membrane module; The pressure data and composition data of the permeate gas are obtained by means of a pressure gauge and an online component analyzer arranged on the outlet pipeline of the membrane module.

5. The method according to claim 3, characterized in that: The membrane separation parameters include: Gas permeability coefficient, membrane area and concentration target parameters; Wherein, the target parameters of the concentration include the concentration multiple or the yield.

6. The method according to claim 5, characterized in that The vacuum target value of the permeate side is determined by calculating the following formula: F·x i =S·y i +W·z i S·x i =J i ·(p I ·x i -p e ·y i )A p v =103.15-p e Where n is the total number of gas components in the raw gas, F is the raw gas flow rate, x i is the mole fraction of the i-th gas component in the feed gas, The raw gas flow rate and the molar fraction of each gas component in the raw gas are the raw gas component data; S is the permeate flow rate, y i is the mole fraction of the i-th gas component in the permeate gas, The permeate gas flow rate and the molar fraction of each gas component in the permeate gas are the permeate gas component data; W is the tail gas flow rate, which is determined according to the feed gas flow rate and the permeate gas flow rate; i is the mole fraction of the i-th gas component in the exhaust gas, The mole fraction of the i-th gas component in the tail gas is determined according to the mole fraction of the i-th gas component in the feed gas and the mole fraction of the i-th gas component in the permeate gas; I is the pressure data of raw gas, p e is the pressure data of the permeate gas; J i is the gas permeability coefficient of the i-th gas component, A is the membrane area, p v is the vacuum degree, and the target parameter of the concentration is the concentration multiple, the concentration multiple of the i-th gas is recorded as K i , When the target parameter of the concentration is the yield, the yield of the i-th gas is recorded as Y i , 7. The method according to any one of claims 1 to 6, characterized in that: The step of adjusting the vacuum degree on the permeate side to a predetermined vacuum degree target value comprises: The vacuum degree on the permeate side is adjusted to the vacuum degree target value by controlling the power of the vacuum pump pre-set in the permeate side outlet pipeline.

8. A membrane gas separation system, characterized in that: include: control device and gas processing device; wherein, The control device is configured to: adjust the vacuum degree on the permeate side to a predetermined vacuum degree target value; The gas treatment device is configured to separate and concentrate the permeated gas when the vacuum degree on the permeate side reaches the target value; Wherein, the vacuum degree target value is greater than a preset vacuum degree minimum value.

9. A computer storage medium, wherein a computer program is stored in the computer storage medium, and when the computer program is executed by a processor, the membrane gas separation method according to any one of claims 1 to 7 is implemented.

10. A terminal, comprising: A memory and a processor, wherein the memory stores a computer program; wherein, The processor is configured to execute the computer program in the memory; When the computer program is executed by the processor, the membrane gas separation method according to any one of claims 1 to 7 is implemented.

Images