KR20150122985A - Apparatus and method for recovery of retentate using gas separation membrane - Google Patents

Abstract

The first penetration gas into second penetration gas and second collection gas with respect to the set second SC value; and a third gas separation membrane module for separating the second penetration gas in the second gas separation membrane module on the rear end of the apparatus for collecting target gas into third collection gas and third penetration gas with respect to the set third SC value. The apparatuses for collecting target gas include an apparatus for collecting first target gas and an apparatus for collecting second target gas which are series-connected, and is additionally equipped with an injection gas supply unit for supplying injection gas including target gas to be collected on the front end of the apparatus for collecting first target gas to the gas mixing unit in the apparatus for collecting first target gas.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-concentration target gas recovery apparatus and method using a gas separation membrane module,

The present invention relates to a highly concentrated target gas recovery apparatus and method using a gas separation membrane module, and more particularly, to a target gas recovery apparatus comprising a first gas separation membrane module and a second gas separation membrane module, Thereby enhancing the degree of concentration of the target gas through the plurality of target gas collecting apparatuses and maintaining the target gas concentration of the injected gas injected into the first gas separation membrane module in each of the target gas collecting apparatuses constant, The present invention relates to a highly concentrated target gas recovery apparatus and method using a gas separation membrane module capable of stably maintaining a target gas concentration contained in a recovery gas recovered by the recovery gas recovery unit.

SF ₆ is a typical electrical insulating material for electric power equipment and is used in the cleaning process of semiconductor wafers and LCD panels. Such SF ₆ has been the impact on global warming is known to be higher than carbon dioxide, more than 23,900 times, global warming is one of the largest six materials cited in the UNFCCC Parties Conference held in Kyoto in 1997 bar . Therefore, a process for SF ₆ is urgently required.

The processing method for the SF _6, there is a first method to decompose SF _6. Since SF ₆ is very stable, it requires a high energy such as plasma to decompose and has the disadvantage that by-products having high toxicity and corrosivity such as S ₂ F ₁₀ , SF ₄ , and HF are produced during the decomposition process. If such problems with the decomposition considering the continuous price rise of SF ₆ by effectively recovering SF ₆ is highly desirable in terms of reducing production costs to promote reuse.

Techniques for recovering SF ₆ is a technology for recovering only the SF ₆ in a mixed containing the SF ₆ gas, naengbeop seam in detail, there is a method such as a PSA (pressure swing adsorption) method, membrane separation process, the two of the gas separation membrane module Many studies have been conducted on the membrane separation method used. The membrane separation method is advantageous in that the structure of the apparatus is relatively simple and the recovery rate is comparatively excellent. An example of the membrane separation method is disclosed in Korean Patent No. 10-1249261.

In the membrane separation method, the waste gas is injected into the separation membrane module, and the separation membrane module proceeds by separating the injected waste gas into SF ₆ (recovery gas) and other gases (permeation gas). The treatment characteristics of the membrane separation method are determined by the selectivity and permeability of the membrane module. A high permeability of the membrane module is advantageous in that the treatment capacity is large. However, since the membrane having high permeability is low in selectivity, have.

As described above, the selectivity and the transparency of the separation membrane module have a trade-off. In the conventional case, a plurality of separation membrane modules are formed in a multi-stage configuration to enable a separation performance and a processing capacity of a certain level. However, when the plurality of separation membrane modules are repeatedly constructed in a multi-stage form, there is a disadvantage that the device configuration becomes complicated. In order to solve this problem, the present applicant has provided two separation membrane modules (first separation membrane module and second separation membrane module) through Korean Patent Application No. 2013-118138 and circulated the recovery gas and the permeation gas of the first separation membrane module And a technique for improving the recovery rate has been proposed.

Korean Patent No. 10-1249261 Korean Patent Application No. 2013-118138

The target gas recovery device including the first gas separation membrane module and the second gas separation membrane module is repeatedly arranged in series so as to improve the degree of concentration of the target gas through the plurality of target gas recovery devices, A gas separation membrane module capable of stably maintaining a target gas concentration contained in a recovery gas recovered by each target gas recovery device by maintaining a target gas concentration of an injection gas injected into a first gas separation membrane module in the apparatus to be constant And an object of the present invention is to provide a highly concentrated target gas recovery apparatus and method.

According to an aspect of the present invention, there is provided a highly concentrated target gas recovery device using a gas separation membrane module, comprising a plurality of target gas recovery devices connected in series, the target gas recovery device including an injection gas, A second gas recovery unit for separating the mixed gas of the injected gas, the second recovered gas and the third recovered gas into a first permeated gas and a first recovered gas in accordance with the set first SC value, And a second gas separation membrane module for separating the first permeable gas into a second permeable gas and a second recovered gas in accordance with a set second SC value, Further comprising: a third gas separation membrane module for separating the second permeable gas of the module into a third recovered gas and a third permeated gas in accordance with a set third SC value, wherein the second recovered gas and the third recovered gas are separated from the The second SC value and the third SC value are set so that the target gas concentration of the second recovered gas and the target gas concentration of the third recovered gas are in agreement with the target gas concentration of the injected gas, Wherein the target gas recovery device comprises a first target gas recovery device and a second target gas recovery device connected in series, wherein an injection gas containing a target gas to be recovered is disposed at a front end of the first target gas recovery device, And an injection gas supply unit for supplying the gas mixture to the gas mixing unit of the target gas recovery apparatus.

The second SC value [theta] ₁₂ of the second gas separation membrane module of the first target gas recovery device is calculated through the following equation.

(expression)

(? ₁₂ is the second SC value of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas,? ₁₁ and? ₁₂ are the first gas separation membrane module of the first target gas recovery device and the second gas separation membrane Selectivity of module)

The second SC value (? ₂₂ ) of the second gas separation membrane module of the second target gas recovery device is calculated by the following equation.

(expression)

( ₂₂ is the second SC value of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas, and? ₂₁ and? ₂₂ are the second gas recovery device's first gas separation membrane module and the second gas separation membrane Selectivity of module)

The third SC value (? ₂₃ ) of the third gas separation membrane module is calculated by the following equation.

(expression)

(θ ₂₃ is the third third SC value of the gas separation membrane module, x ₀ is the target gas concentration, x ₁ in the injection gas is a first target gas first target gas concentrations, α ₂₁ and α ₂₂ for recovering gas of the recovery device is Selectivity of the first gas separation membrane module and the second gas separation membrane module, respectively, of the second target gas recovery device, and? ₂₃ is the selectivity of the third gas separation membrane module)

The first SC value [theta] ₁₁ of the first gas separation membrane module of the first target gas recovery device is calculated through the following equation.

(expression)

(θ ₁₁ is in a first gas separation membrane of claim 1, SC value applied to the module, e ₁₁ has a first target gas also the first target concentration of the gas separation membrane module of the harvesting device, x ₀ is injecting gas in the target gas recovery device Target gas concentration,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device)

The first SC value (? ₂₁ ) of the first gas separation membrane module of the second target gas recovery device is calculated by the following equation.

(expression)

(θ ₂₁ is the second target gas first SC values applied to a first gas separation membrane module of the harvesting device, e ₂₁ of the second target base target enrichment, x ₁ of the first gas separation membrane module of the recovery device is injected into the gas ( The target gas concentration in the first recovery gas of the first target gas recovery device),? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device)

Wherein the first compression tank supplies a mixed gas of the injected gas and the second recovered gas to the first gasketing membrane module at a specific supply pressure, 1 permeable gas to the second gas separation membrane module at a specific supply pressure, and the supply pressure of the first compression tank and the supply pressure of the second compression tank are set to be the same. Further, the supply pressure P of the first compression tank and the supply pressure P of the second compression tank are calculated by the following equations.

(expression)

(A is the optimum membrane area of the gas separation membrane corresponding to the changed supply pressure, A ₀ is the optimum membrane area of the gas separation membrane corresponding to the reference supply pressure, P ₀ is the reference supply pressure, and P is the changed supply pressure)

A first SC regulator for controlling the first permeable gas flow rate and the first recovered gas flow rate of the first gas separation membrane module by controlling the first SC value of the first gas separation membrane module according to the set target concentration, A second SC regulator controlling the second permeate flow rate of the second gas separation membrane module and the second recovered gas flow rate by controlling the second SC value of the second gas separation membrane module so that the gas concentration coincides with the target gas concentration in the injected gas , The third SC value of the third gas separation membrane module is controlled so that the target gas concentration of the third recovered gas matches the target gas concentration in the injected gas so that the third permeate flow rate and the third recovered gas flow rate of the third gas separation membrane module And a third SC regulator for regulating the second SC.

The membrane areas of the first gas separation membrane module and the second gas separation membrane module of the first target gas recovery device are set through the following equations (1) and (2), respectively.

(Equation 1)

)(A ₁₁ is the first target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module, P _{B, 11} is the permeability of the first recovered gas of the first target gas recovery device,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas, r ₁ is the rate of increase in the flow rate of the mixed gas including the second recovered gas and the third recovered gas as compared with the first injected gas injected into the first gas separation membrane module of the first target gas recovery device , r ₁ is

)

(Equation 2)

(A ₁₂ has a first target second membrane area of the gas separation membrane module for gas recovery apparatus, θ ₁₂ is the second SC value, P _B, of the second gas separation membrane module of the first target gas recovery unit ₁₁ is the first target base P _{B, 12} is the permeability of the second recovered gas of the first target gas collecting device, α ₁₁ is the selectivity of the first gas separator module of the first target gas collecting device, α ₁₂ Is the selectivity of the second gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas)

The membrane areas of the first gas separation membrane module and the second gas separation membrane module of the second target gas recovery device are set through the following equations (1) and (2), respectively.

(Equation 1)

, r₂는

)(A ₂₁ is the second target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module,? ₂₁ is the first SC value of the first gas separation membrane module of the second target gas recovery device, P _{B, 21} is the permeability of the first recovery gas of the second target gas recovery device , α ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁

, r ₂ is

)

(Equation 2)

(A ₂₂ is the film area of the second gas separation membrane module of the second target gas recovery device,? ₂₂ is the second SC value of the second gas separation membrane module of the second target gas recovery device, P _B, P _{B, 22} is the permeability of the second recovered gas of the second target gas collecting device,? ₂₁ is the selectivity of the first gas separator module of the second target gas collecting device,? ₂₂ X ₁ is the target gas concentration in the injected gas (the first recovered gas of the first target gas recovery device), and the target gas concentration in the second gas recovery device is the selectivity of the second gas separation membrane module of the second target gas recovery device,

The membrane area of the third gas separation membrane module is set by the following equation.

(expression)

, r₁₂는

)(A ₂₃ is the membrane area of the third gas separation membrane module, f ₀ is the flow rate of the injected gas, P ₀ is the initial supply pressure of the first compression tank, and θ ₁₁ is the pressure of the first gas separation membrane module 1, SC value, θ ₂₁ is the second target gas first SC value, θ ₂₂ of the first gas separation membrane module of the recovery device is a second second SC value, θ ₂₃ of the gas separation membrane module of the target gas recovery device of claim 3 is the third SC value of the gas separation membrane module, P _{B, 23} is the permeability of the third recovered gas,? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device,? ₂₂ is the second target gas recovery device ? ₂₃ is the selectivity of the third gas separation membrane module, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁ is the selectivity of the second gas separation membrane module

, r ₁₂

)

The first gas separation membrane module of the first target gas recovery device, the second gas separation membrane module of the first target gas recovery device, the first gas separation membrane module of the second target gas recovery device, the second gas separation membrane module of the second target gas recovery device, And the membrane area (A) of the third gas separation membrane module are set by the following equations.

(expression)

(A is the optimum membrane area of the gas separation membrane corresponding to the changed supply pressure, A ₀ is the optimum membrane area of the gas separation membrane corresponding to the reference supply pressure, P ₀ is the reference supply pressure, and P is the changed supply pressure)

The injected gas that contains the target gas is a waste gas containing the fluoride gas or a waste gas including SF _6, wherein the target gas is SF ₆ gas or fluoride.

A method for recovering a high concentration target gas using a gas separation membrane module according to the present invention is characterized in that a plurality of target gas recovery devices are connected in series and the target gas recovery device comprises a first gas separation membrane module and a second gas separation membrane module, Separating the mixed gas into a first permeable gas and a first recovered gas through the gas separation membrane module, and separating the first permeable gas of the first gas separation membrane module into a second permeable gas and a second recovered gas, , The third gas separation membrane module separates the second permeation gas of the second gas separation membrane module into a third recovery gas and a third permeation gas, and the first gas separation membrane module is provided with an injection gas, a second recovery gas and a third recovery gas Wherein the first gas separation membrane module separates the mixed gas of the injected gas, the second recovered gas and the third recovered gas into the first permeated gas and the first recovered gas in accordance with the set first SC value, detach The module separates the first permeable gas into a second permeable gas and a second recovered gas in accordance with a second SC value, and the third gas permeable membrane module separates the second permeable gas into a third permeable gas, And the third recovered gas, and the second SC value and the third SC value are set such that the target gas concentration of the second recovered gas and the target gas concentration of the third recovered gas match the target gas concentration of the injected gas .

The highly concentrated target gas recovery apparatus and method using the gas separation membrane module according to the present invention has the following effects.

The target gas in the recovery gas can be concentrated at a high concentration through the plurality of target gas recovery devices connected in series. By setting the second SC value and the third SC value so that the target gas concentration of the second recovered gas and the third recovered gas supplied to the gas mixing portion of each target gas collecting device matches the target gas concentration of the injected gas, The target gas concentration in the first recovered gas to be finally recovered can be kept constant, and the reliability of the membrane separation process can be improved. At the same time, the second permeable gas of the target gas recovery device at the downstream end is separated again into the recovery gas and the permeable gas through the third gas permeable membrane module, and the permeable gas is discharged, so that the target gas concentration So that it can be minimized.

In addition, by optimally designing the membrane areas of the first and second gas separation membrane modules and selectively controlling the supply pressures of the first and second gas separation membrane modules according to the flow rate of the injected gas, the target gas concentration in the first recovery gas Can be maintained stably and constantly.

Brief Description of the Drawings Fig. 1 is a configuration diagram of a highly concentrated target gas recovery device using a gas separation membrane module according to an embodiment of the present invention.
2 is a graph showing the relationship between the target concentration (e ₁₁ ) (e ₂₁ ), the first SC value (θ ₁₁ ) (θ ₂₁ ), the second SC value θ ₁₂ (θ ₂₂ ) Value (? ₂₃ ) and the like.

First, terms used in this specification are defined as follows.

x ₀ : target gas concentration of the injected gas

x ₁ : target gas concentration of the first recovered gas of the first target gas collecting apparatus

x ₂ : target gas concentration of the first recovered gas of the second target gas collecting apparatus

e ₁₁ : Target concentration degree of the first gas separation membrane module of the first target gas recovery device

e ₁₂ : Target concentration degree of the second gas separation membrane module of the first target gas recovery device

e ₂₁ : target concentration degree of the first gas separation membrane module of the second target gas recovery device

e ₂₂ : target concentration degree of the second gas separation membrane module of the second target gas recovery device

e ₂₃ : target concentration of the third gas separation membrane module

? ₁₁ : the first SC value of the first gas separation membrane module of the first target gas recovery device

? ₁₂ : second SC value of the second gas separation membrane module of the first target gas recovery device

? ₂₁ : the first SC value of the first gas separation membrane module of the second target gas recovery device

? ₂₂ : second SC value of the second gas separation membrane module of the second target gas recovery device

θ ₂₃ : third SC value of the third gas separation membrane module

y ₁ : target gas concentration of the first permeable gas of the first target gas collecting apparatus

y ₂ : target gas concentration of the first transparent gas of the second target gas collecting apparatus

z ₁ : target gas concentration of the second permeable gas of the first target gas collecting apparatus

z ₂ : target gas concentration of the second permeable gas of the second target gas collecting apparatus

f ₀ : flow rate of injected gas

f ₁ : Flow rate of the first recovered gas of the first target gas collecting apparatus

f ₂ : the flow rate of the first recovered gas of the second target gas recovery device

A ₁₁ : Membrane area of the first gas separation membrane module of the first target gas recovery device

A ₁₂ : the membrane area of the second gas separation membrane module of the first target gas recovery device

A ₂₁ : the membrane area of the first gas separation membrane module of the second target gas recovery device

A ₂₂ : Membrane area of the second gas separation membrane module of the second target gas recovery device

? ₁₁ : Selectivity of the first gas separation membrane module of the first target gas recovery device

? ₁₂ : Selectivity of the second gas separation membrane module of the first target gas recovery device

? ₂₁ : Selectivity of the first gas separation membrane module of the second target gas recovery device

? ₂₂ : Selectivity of the second gas separation membrane module of the second target gas recovery device

α ₂₃ : Selectivity of the third gas separation membrane module

P _{B, 11} : Permeation of the first recovered gas of the first target gas collecting device

P _{B, 12} : Permeation of the second recovered gas of the first target gas collecting device

P _{B, 21} : Permeation of the first recovered gas of the second target gas collecting apparatus

P _{B, 22} : Permeation of the second recovered gas of the second target gas collecting device

The target gas recovery device including the first gas separation membrane module and the second gas separation membrane module is repeatedly arranged in series to concentrate the target gas at a high concentration and the first gas separation membrane module is connected to the first gas separation membrane module of each target gas recovery device The second SC value and the third SC value are controlled so that the target gas concentrations of the injected gases (the injected gas, the second recovered gas, and the third recovered gas) A technique for keeping the target gas concentration contained in the recovered gas constant is presented.

In the gas separation membrane module, a highly permeable gas having a relatively small molecular size (hereinafter referred to as a "permeable gas") permeates through pores and a low permeable gas having a relatively large molecular size (hereinafter referred to as a "recovered gas" It is a device which remains in the gas separation membrane module and is recovered. When the injection gas is supplied to the gas separation membrane module, it is separated into the permeation gas and the recovery gas by the gas separation membrane module.

The target gas is the gas to be finally recovered through the gas separation membrane module, for example, SF ₆ contained in the waste gas. The target gas SF ₆ is contained in the injected gas (waste gas) at a predetermined concentration. When the injected gas is separated into the permeated gas and the recovered gas by the gas separation membrane module, a considerable number of target gases are contained in the recovered gas, Includes a small amount of target gas. The reason why the target gas having a relatively large molecular size is contained in the permeation gas is that the target gas having a relatively large molecular size permeates the pores of the gas separation membrane module because the pore size is not constant Because. In other words, it can be explained that the permeability of the target gas in the permeability of the gas permeating the pores of the gas separator module is smaller than the permeability of the other gas in the waste gas, so that the possibility of remaining in the gas separator module is high. Thus, the target gas concentration in the recovered gas is relatively larger than the target gas concentration in the permeated gas.

In the membrane separation method using the gas separation membrane module, it is important to increase the target gas concentration in the recovery gas, to keep the target gas concentration in the recovery gas constant, and to lower the target gas concentration contained in the discharged permeation gas, The invention proposes a technique capable of achieving the above three purposes.

Generally, the permeate gas and the recovered gas are separated through the gas separation membrane module, and the flow rate of the permeate gas and the flow rate of the recovered gas are controlled through a set SC (Stage-cut) value. If one gas separation membrane module is used and the concentration of the target gas contained in the injected gas supplied to the gas separation membrane module is constant, the target gas concentration in the recovery gas can be kept constant through the SC value control. However, when a plurality of gas separation membrane modules are used and the target gas concentration in the gas to be supplied to the gas separation membrane module is fluid, various variables must be considered in controlling the SC value.

The present invention is characterized in that the target gas recovery device is composed of a first gas separation membrane module and a second gas separation membrane module, and the injected gas is separated into a first permeation gas and a first recovered gas through the first gas separation membrane module, The module separates the first permeable gas of the first gas separation membrane module into a second permeable gas and a second recoverable gas as an injector body and separates the second recovered gas of the second gas separation membrane module into an injected gas of the first gas separation membrane module As shown in FIG.

With this configuration, the target gas concentration in the first recovered gas is specified, the first SC value of the first gas separation membrane module is controlled to correspond to the target gas concentration in the first recovered gas, and the target gas concentration The second SC value of the second separation membrane module is controlled so that the second SC value is equal to the target gas concentration in the injection gas. Whereby the target gas concentration in the first recovered gas can be kept constant. When the target gas concentration in the second recovered gas and the target gas concentration in the injected gas are different from each other, the concentration of the target gas contained in the mixed gas (the injected gas + the second recovered gas) supplied to the first gasketing membrane module is changed Even if the first SC value of the first gas separation membrane module is specified, the target gas concentration in the first recovery gas can not be maintained constant.

The present invention also provides a technique for serially connecting a plurality of target gas collecting apparatuses in order to concentrate a target gas in a recovery gas at a high concentration. In addition, considering that the concentration of the target gas contained in the second permeable gas of the second gas separation membrane module of the target gas recovery device increases as the number of the series arrangement stages of the target gas recovery device increases, The second gas permeable substrate of the second gas separation membrane module of the recovery device is recovered to the target gas recovery device at the previous stage through the third gas separation membrane module and the target gas concentration in the third recovery gas of the third gas separation membrane module A third SC value of the third gas separation membrane module is controlled so as to match the target gas concentration of the injected gas injected into the first gas separation membrane module.

In addition, the present invention provides an additional structure for maintaining the target gas concentration in the first recovered gas at a constant level in constructing the target gas recovery apparatus, wherein the first gas separation membrane module satisfies the first SC value and the second SC value, And the optimal membrane area of the second gas separation membrane module.

Hereinafter, a highly concentrated target gas recovery apparatus and method using a gas separation membrane module according to an embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a highly concentrated target gas recovery apparatus using a gas separation membrane module according to an embodiment of the present invention includes a plurality of target gas recovery apparatuses connected in series.

The recovery gas recovered in each of the target gas recovery devices is supplied to the injector body of the target recovery device at the downstream stage and the target gas can be concentrated to a high concentration through the plurality of target recovery devices connected in series. The target gas collecting apparatuses are repeatedly arranged in series. In the following description, two target gas collecting apparatuses (the first target gas collecting apparatus 100 and the second target gas collecting apparatus 200) are connected in series As a reference. In the following description, the detailed configuration of the target gas recovery device, the control of the first SC value, the second SC value and the third SC value, and the design of the optimum film area will be described in detail.

1, the first target gas collecting apparatus 100 and the second target gas collecting apparatus 200 each include a gas mixing unit 110, 210, The first SC compressors 140 and 240, the second compression tank 150 and 250, the second gas separation membrane module 130 and the second SC separator 140, Module 160 (260) and a second SC regulator (170) (270).

The first target gas recovery apparatus 100 is provided with an injection gas supply unit 10 and the injection gas supply unit 10 is connected to the gas mixing unit 110 of the first target gas recovery apparatus 100, , And SF ₆ . The first recovered gas of the first gas separation membrane module 130 of the first target gas recovery apparatus 100 is not injected into the injector body 100 but the injected gas supply unit 10 is not provided at the front end of the second target gas recovery apparatus 200, And is supplied to the gas mixing section 210 of the second target gas recovery apparatus 200. That is, the injection gas supplied to the gas mixture portion of each target gas recovery device is the first recovery gas of the first gas separation membrane module of the target gas recovery device at the preceding stage, An injection gas supply unit 10 is provided and an injection gas (for example, waste gas including SF ₆ ) of the injection gas supply unit 10 is supplied to the gas mixing unit 110.

The injected gas supply unit 10 supplies an injected gas containing a target gas, and the target gas is a gas to be recovered through a target gas recovery apparatus and a third gas separation membrane module 32, A waste gas containing SF ₆ or a waste gas containing a fluorinated gas such as NF ₃ or CF ₄ may be used as the injector sieve, and SF ₆ , NF ₃ , CF _4, and the like correspond to the target gas. The target gas is mixed in the injection gas at a predetermined concentration. In the following explanation it will be described on the basis of the waste gas including SF _6.

The gas mixing units 110 and 210 may supply the injected gas supplied from the injected gas supply unit 10 or the first recovered gas of the first gas separation membrane module 130 of the target gas recovery apparatus at the previous stage to the second gas separation membrane module 160) 260 and a third recovered gas supplied from the third gas separation membrane module 32. The second recovered gas supplied from the first gas recovery membrane module 160 and the third recovered gas supplied from the third gas separation membrane module 32 are mixed. The first compression tank 120 and the second compression tank 220 compress the mixed gas of the injected gas (or the first recovered gas), the second recovered gas and the third recovered gas to a predetermined pressure, (230). ≪ / RTI > The supply pressure of the mixed gas mixed in the gas mixing units 110 and 210 to the first gas separation membrane modules 130 and 230 may vary according to the change in flow rate of the gas to be injected, which will be described later.

The first gas separation membrane modules 130 and 230 serve to separate the mixed gas supplied from the gas mixing parts 110 and 210 into a first permeable gas and a first recovered gas. Here, the mixed gas means a mixed gas of an injected gas (or a first recovered gas), a second recovered gas, and a third recovered gas, and the first gas separation membrane modules 130 and 230 The separation of the recovered gas and the permeated gas is carried out using the gas molecular size difference.

The first gas separation membrane modules 130 and 230 (and the second gas separation membrane modules 160 and 260 and the third gas separation membrane module 32) are aggregates of hollow particles having pores formed on their surfaces, ₆ gas with relatively small molecular size such as O ₂ , N ₂ and CO ₂ permeates the pores of the membrane rapidly and is discharged. The relatively large molecular size SF ₆ does not permeate the pores, Is recovered. The gas to be discharged through the pores of the separation membrane is a permeation gas, and the gas recovered from one end of the separation membrane is a recovery gas. At this time, relative to the molecular size of a small gas (O _2, N _2, CO _2, etc.) as well as relative to the molecular size is larger SF ₆ gas is also there is discharged by passing through the pores of the membrane, the permeability of the SF ₆ gas O _2, N ₂ , and CO _2. Therefore, SF ₆ gas can be recovered as a recovered gas, and substantially gases such as O ₂ , N ₂ and CO ₂ are highly permeable gases and SF ₆ gas is a low permeable gas .

The first SC (stage-cut) regulator set target enrichment (e _11), a first SC (stage-cut) value (θ ₁₁₎ of the first gas separation membrane module 130, 230 in accordance with (e ₂₁₎ (θ ₂₁₎ controls (see Fig. 2) it serves to adjust the flow rate and the permeate gas recovered gas flow rate of the first gas separation membrane module (130, 230). The SC value means the ratio of the flow rate of the permeated gas to the flow rate of the injected gas as shown in Equation 2 below. For example, if the SC value is 0.95, then the permeate flow rate versus the inlet gas flow rate is 95% and the recovered gas flow rate is 5%, which means that 5% of the total injected gas is recovered (see Equations 1 and 2) .

(Formula 1) Injected gas flow rate (F _f ) = permeate gas flow rate (F _p ) + recovered gas flow rate (F _r )

(Equation 2) SC = permeable gas flow rate (F _p ) / injected gas flow rate (F _f )

In the present invention, the 1 SC value (θ ₁₁₎ (θ ₂₁₎ is controlled in accordance with FIG target concentration is set _{(e 11) (e 21)} . The target gas concentration x ₀ of the injection gas (waste gas) of the first target gas recovery apparatus 100 and the target gas concentration x ₁ of the injection gas (first recovery gas) of the second target gas recovery apparatus 200 The target concentration degree e ₁₁ of the first gas separation membrane module 130 of the first target gas recovery apparatus 100 and the target concentration degree e ₁₁ of the first gas separation membrane module 230 of the second target gas recovery apparatus 200 concentration of the target) is also (e ₂₁₎ is controlled differently.

Target concentration of the first gas separation membrane module 130, 230 also (e ₁₁₎ (e ₂₁₎ is the target gas concentration in the injected gas (x ₀ or x ₁₎ than the first number of target gas concentration in the gas (x _1, or x ₂ ) (see Equation 3 and Equation 4). When the target gas concentration (x ₁ or x ₂ ) in the first recovery gas is set while the target gas concentration (x ₀ or x ₁ ) in the injection gas is determined, the target concentration (e ₁₁ ) (e ₂₁ ) have. The target gas concentration (x ₁ or x ₂ ) in the first recovered gas may be the concentration of the target gas that is finally recovered through the first target gas recovery apparatus 100 or the second target gas recovery apparatus 200.

(Equation 3) The target concentration (e ₁₁ ) = x ₁ / x ₀

(e ₁₁ is the target concentration of the first gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration of the injected gas, and x ₁ is the target gas concentration of the first recovery gas of the first target gas recovery device)

(Equation 4) Target concentration (e ₂₁ ) = x ₂ / x ₁

(e ₂₁ is the second target gas recovery second gas target concentration of the membrane module is, x ₁ is the first target base target gas concentration, x ₂ of the first number of gas recovery apparatus of the second target gas recovery on the device Target gas concentration of the first recovered gas)

The target concentration degree e ₁₁ of the first gas separation membrane module 130 of the first target gas recovery apparatus 100 and the target concentration degree e 1 of the first gas separation membrane module 230 of the second target gas recovery apparatus 200 If e ₂₁₎ is set, the first gas separation membrane module of the first target gas recovering apparatus 100, the first SC value of the first gas separation membrane module (130) (θ ₁₁₎ and the second target gas recovery apparatus 200 of the The first SC value [theta] ₂₁ of the second subtractor 230 is calculated by the following Expression 5 and Expression 6, respectively. The first SC value (θ ₁₁₎ (θ ₂₁₎ to Fig. (E ₁₁₎ the target concentration for the calculation of (e ₂₁₎ in addition to the target gas concentration (x ₀₎ in the injection gas (x _1), a first gas separation membrane module ( 130) 230 selectivity? ₁₁ (? ₂₁ ) is required. The selectivity (alpha) of the gas separation membrane module means the ratio of the permeability of the permeable gas to the permeability of the recovered gas.

The gas injected into the first gas separation membrane modules 130 and 230 may be injected into the second recovery gas of the second gas separation membrane modules 160 and 260 and the third gas separation membrane module 32 of the second gas separation membrane module 260, Of the third recovered gas. Therefore, in calculating the first SC value (? ₁₁ ) (? ₂₁ ), the target gas concentration of the second recovered gas and the target gas concentration information of the third recovered gas are obtained in addition to the target gas concentration (x ₀ or x ₁ ) In the present invention, the target gas concentration of the second recovered gas and the target gas concentration of the third recovered gas are controlled to coincide with the target gas concentration (x ₀ or x ₁ ) in the injected gas, and the first SC value θ ₁₁₎ (the target gas concentration in the injected gas to the calculation formula of θ ₂₁₎ (x ₀ or x ₁₎ or only two recovery target gas concentration or a third number of times any of the information of the target gas concentration in the gas in the gas may be applied to the 1 SC value (? ₁₁ ) (? ₂₁ ) can be calculated. The reason for controlling the target gas concentration of the second recovered gas and the third recovered gas target gas concentration to be in agreement with the target gas concentration (x ₀ or x ₁ ) in the injected gas is that the target gas concentration in the first recovered gas (x ₁ or x ₂ ).

(Equation 5)

(θ ₁₁ is in a first gas separation membrane of claim 1, SC value applied to the module, e ₁₁ has a first target gas also the first target concentration of the gas separation membrane module of the harvesting device, x ₀ is injecting gas in the target gas recovery device Target gas concentration,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device)

(Equation 6)

(θ ₂₁ is the second target gas first SC values applied to a first gas separation membrane module of the harvesting device, e ₂₁ of the second target base target enrichment, x ₁ of the first gas separation membrane module of the recovery device is injected into the gas ( The target gas concentration in the first recovery gas of the first target gas recovery device),? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device)

Next, the second compression tank 150 compresses the first permeable gas of the first gas separation membrane modules 130 and 230 to a predetermined pressure and supplies the compressed gas to the second gas separation membrane modules 160 and 260 .

The injected gas supplied from the injected gas supplying unit 10 is set to be supplied at a constant flow rate but has a characteristic of being changed in real time due to various factors such as equipment condition, temperature, pressure, etc. on the injected gas supplying unit 10 side, The flow rates of the permeate gas and the recovered gas separated by the first gasketing membrane module 130 and the second gasketing membrane module 160, 260 are influenced even if the SC value is specified. That is, if the flow rate of the injected gas is changed, the flow rate of the permeated gas and the recovered gas can not be maintained constant.

In order to cope with the change in the flow rate of the injected gas, the supply pressure of the mixed gas injected into the first gasketing membrane module 130 (230) and the second gasketing module 160 (260) It is necessary to change it. Specifically, the supply pressure P of the first compression tank 120 (220) and the second compression tank 150 (250) can be set as shown in Equation (7) below. That is, if the change occurs in the flow rate of the injection gas, the injection flow rate ratio first supply pressure to the (f / f ₀₎ of the base (P _o) for multiplying the first compression tank 120, 220 and the second compression tank ( 150) < / RTI > At this time, the supply pressure of the first compression tank 120 (220) and the supply pressure of the second compression tank 150 (250) are set to be the same, and the first compression tank and the second compression tank The supply pressure of the tank is also set equal.

A supply pressure control unit may be further provided to control the supply pressure of the first and second compression tanks 120 and 220 and the supply pressure of the second compression tank 150 and 250 according to the flow rate of the injection gas, The pressure control unit may check the change in flow rate of the injection gas and set the supply pressure of the first compression tank 120 (220) and the supply pressure of the second compression tank 150 (250) using Equation (7).

(Equation 7)

(P is the feed pressure, f is a real-time rate of change injection gas, f ₀ is the flow rate of the initial fill gas, P ₀ is the first compression tank and the second compression tank of the first compression tank and the second compression tank in which real-time settings Of the initial supply pressure)

The second gas separation membrane modules 160 and 260 divide the first permeable gas of the first gas separation membrane modules 130 and 230 into a second permeable gas and a second recoverable gas as an injector.

The second SC regulator 170 may be controlled by the second gas separator module 160 (260) such that the target gas concentration in the second recovery gas of the second gas separator module 160 (260) 260 of the second SC.

Specifically, the second SC value (? ₁₂ ) of the second gas separation membrane module 160 of the first target gas recovery device 100 is the same as the second SC value? ₁₂ of the second gas separation membrane module 160 of the first target gas recovery device 100 The target gas concentration of the second recovered gas is controlled to coincide with the target gas concentration of the injected gas injected into the first gas separation membrane module 130 of the first target gas recovery apparatus 100 and the second target gas recovery apparatus 200 The second SC value of the second gas separation membrane module 260 of the second gas separation membrane module 260 of the second target gas recovery device 200 is higher than the target gas concentration of the second recovery gas of the second gas separation membrane module 260 of the second target gas recovery device 200, Is coincident with the target gas concentration of the injected gas injected into the first gas separation membrane module (230) of the first gas separation membrane module (200).

First, the process of calculating the second SC value (? ₁₂ ) of the second gas separation membrane module 160 of the first target gas recovery apparatus 100 will be described below.

Claim 2 SC value equation calculation of (θ ₁₂₎ calculated by default, the 1 SC value (θ ₁₁₎ identical to the calculation formula (formula 5), the 1 SC value (θ ₁₁₎ is also the target concentration of the calculation formula (e ₁₁₎ instead it is applied by replacing the even (e ₁₂ target concentration) of the second gas separation membrane module 160 (260). In addition, the first application by replacing the even (α _12), the selection of the gas separation membrane module selection unit 130 also (α ₁₁₎ instead of the second gas separation membrane module 160 (260).

The target concentration of the second gas separation membrane module 160 is determined by the target concentration e ₁ of the second gas separation membrane module 160 as the first permeation gas of the first gas separation membrane module 130, Is set to the ratio of the target gas concentration (Y _R ) in the second recovery gas to the target gas concentration (y ₁ ) in the second recovery gas. Further, as the second number of the target gas density (Y _R) is set to match the target gas concentration (x ₀₎ in the injection gas in the gas in the present invention, the target concentration of the second gas separation membrane module 160 is also (e ₁₂ ) Can be set to the ratio of the target gas concentration (x ₀ ) in the injection gas to the target gas concentration (y ₁ ) in the first transmission gas as shown in the following equation (8). In addition, the target gas concentration (y ₁ ) in the first transparent gas is arranged as shown in Equation (9).

(8) e ₁₂ = Y _R / y ₁ = x ₀ / y ₁

(e ₁₂ is the first target gas recovery second gas separation membrane target concentration of the module also, y ₁ is the first target a first transmission target gas concentration, Y _R in the gas in the gas recovery device has a first target gas recovery on the device Target gas concentration in the second recovered gas, x ₀ is the target gas concentration in the injected gas)

(Equation 9)

Thus, the 1 SC value (θ ₁₁₎ the target concentration of the calculation expression is also (e ₁₁₎ instead of the target enrichment (e ₁₂₎ of the second gas separation membrane module 160 is applied in place, the 1 SC value (θ ₁₁ ) Calculation formula of the second SC value ₁₂ applied instead of the target gas concentration (y ₁ ) in the first permeable gas in place of the target gas concentration (x ₀ ) in the injected gas is summarized as shown in the following Equation 10 .

(Equation 10)

(? ₁₂ is the second SC value of the first target gas recovery device, x ₀ is the target gas concentration in the purged gas,? ₁₁ and? ₁₂ are the first gas separation membrane module of the first target gas recovery device ) And selectivity of the second gas separation membrane module)

Next, the second SC value (? ₂₂ ) of the second gas separation membrane module 260 of the second target gas recovery device 200 is converted to the second SC value? ₂₂ of the second gas separation membrane module 260 of the first target gas recovery device 100 a second SC value there is calculated through the same calculation process, and (θ _12), the first target gas recovery apparatus of the first transmission target gas concentration (y ₁₎ instead of the second target gas recovery apparatus 200 in the gas of 100 The target gas concentration (y ₂ ) in the first transparent gas (see Equation 11) is applied, and the second SC value? ₂₂ is finally set as shown in Equation 12.

(Expression 11)

(Expression 12)

( ₂₂ is the second SC value of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas, and? ₂₁ and? ₂₂ are the second gas recovery device's first gas separation membrane module and the second gas separation membrane Selectivity of module)

The above-described second SC value (θ ₁₂₎ (θ ₂₂₎ of claim 2 SC value satisfying that matches the target gas concentration in the injected gas target gas concentration of the second recovery gas through Equation (θ ₁₂₎ (θ ₂₂ ) Can be calculated. The second SC regulator 170 (270) determines the second SC value (? ₁₂ ) (? ₁₂ ) using the second SC value calculation formula under the condition that the target gas concentration in the second recovered gas is equal to the target gas concentration in the purged gas θ ₂₂₎ can be calculated, the second SC value (θ _{12) (22} calculates θ) is applied to the operation of the second gas separation membrane module 160 (260).

In order to keep the target gas concentration of the first recovered gas constant, the first gas separation membrane module 130 and the second gas separation membrane module 160 (260) area. For this, the first gas separation membrane module 130 and the second gas separation membrane module 160 of the first target gas recovery device 100 are designed as shown in Equations 13 and 14, respectively, and the second target gas recovery device 200 The first gas separation membrane module 230 and the second gas separation membrane module 260 may be designed as shown in Equations 15 and 16, respectively. In addition, the optimal film area of the third gas separation membrane module 32 to be described later can be designed as shown in Equation (17).

(Expression 13)

)
(A ₁₁ is the first target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module, P _{B, 11} is the permeability of the first recovered gas of the first target gas recovery device,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas, r ₁ is the rate of increase in the flow rate of the mixed gas including the second recovered gas and the third recovered gas as compared with the first injected gas injected into the first gas separation membrane module of the first target gas recovery device , r ₁ is

)

(Equation 14)

(A ₁₂ has a first target second membrane area of the gas separation membrane module for gas recovery apparatus, θ ₁₂ is the second SC value, P _B, of the second gas separation membrane module of the first target gas recovery unit ₁₁ is the first target base P _{B, 12} is the permeability of the second recovered gas of the first target gas collecting device, α ₁₁ is the selectivity of the first gas separator module of the first target gas collecting device, α ₁₂ Is the selectivity of the second gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas)

(Expression 15)

, r₁₂는

)
(A ₂₁ is the second target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module,? ₂₁ is the first SC value of the first gas separation membrane module of the second target gas recovery device, P _{B, 21} is the permeability of the first recovery gas of the second target gas recovery device , α ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁

, r ₁₂

)

(Expression 16)

(A ₂₂ is the film area of the second gas separation membrane module of the second target gas recovery device,? ₂₂ is the second SC value of the second gas separation membrane module of the second target gas recovery device, P _B, P _{B, 22} is the permeability of the second recovered gas of the second target gas collecting device,? ₂₁ is the selectivity of the first gas separator module of the second target gas collecting device,? ₂₂ X ₁ is the target gas concentration in the injected gas (the first recovered gas of the first target gas recovery device), and the target gas concentration in the second gas recovery device is the selectivity of the second gas separation membrane module of the second target gas recovery device,

(Equation 17)

, r₁₂는

)
(A ₂₃ is the membrane area of the third gas separation membrane module, f ₀ is the flow rate of the injected gas, P ₀ is the initial supply pressure of the first compression tank, and θ ₁₁ is the pressure of the first gas separation membrane module 1, SC value, θ ₂₁ is the second target gas first SC value, θ ₂₂ of the first gas separation membrane module of the recovery device is a second second SC value, θ ₂₃ of the gas separation membrane module of the target gas recovery device of claim 3 is the third SC value of the gas separation membrane module, P _{B, 23} is the permeability of the third recovered gas,? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device,? ₂₂ is the second target gas recovery device ? ₂₃ is the selectivity of the third gas separation membrane module, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁ is the selectivity of the second gas separation membrane module

, r ₁₂

)

Although it is possible to set the optimal membrane area of the gas separation membrane module through the above-described equations 13 to 17, it is difficult to fabricate the gas separation membrane module with the optimum membrane area, If it is difficult to keep the supply pressure at the reference supply pressure (P ₀ ), it is also possible to maintain the performance of the gas separation membrane module by varying the supply pressure P and accordingly changing the membrane area. Specifically, in a state where the optimal membrane area A ₀ for each gas separation membrane module is calculated through the optimum membrane area calculating equation of A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ , and A ₂₃ , And the membrane area A ₀ of each gas separation membrane module can be set by multiplying the supply pressure P by the ratio of the reference supply pressure P ₀ to the supply pressure P (see equation 18).

(Expression 18)

(A is the optimum membrane area of the gas separation membrane corresponding to the changed supply pressure, A ₀ is the optimum membrane area of the gas separation membrane corresponding to the reference supply pressure, P ₀ is the reference supply pressure, and P is the changed supply pressure)

The detailed configuration of the target gas recovery device, the control of the first SC value and the second SC value, and the optimum film design have been described above. The target gas concentration in the recovery gas can be maximized through the first target gas recovery device 100 and the second target gas recovery device 200 as described above and the second gas separation membrane module 160 of each target gas recovery device ) 260 is controlled so that the target gas concentration of the second recovered gas matches the target gas concentration of the injected gas of the first gasketing module 130 (230) It is possible to maintain the target gas concentration in the single recovery gas at a constant level. That is, it becomes possible to concentrate the target gas at a high concentration and to maintain the target gas concentration of the recovered gas at a constant level.

On the other hand, in the first target gas recovery apparatus 100, the second permeable gas of the second gas separation membrane module 160 is discharged to the outside, but the injected gas of the second target gas recovery apparatus 200 is higher than the target gas concentration The first gas recovery device 100 of the second target gas recovery device 200 is disposed in the second gas permeable body of the second gas separation membrane module 260 in the first target gas recovery device 100, A larger amount of target gas is contained than the second permeable gas of the second gas separation membrane module 160 of the first gas separation membrane module 100. Further, as the number of series connection stages of the target gas recovery device is increased, the amount of target gas included in the second transmission gas of the second gas separation membrane module is increased. Therefore, the second permeable gas of the second gas separation membrane module of the second-stage or higher-stage target gas recovery device needs to be separated into the recovery gas and the permeable gas again.

To this end, the third gas separation membrane module 32 is applied in the present invention. The third gas separation membrane module 32 separates the second permeation gas of the second gas separation membrane module 260 of the target gas recovery device at the downstream end into the third recovery gas and the third permeation gas as an injector, And the third recovered gas is supplied to the gas mixing portion 110 of the target gas recovery device at the preceding stage. As the second permeable gas is again separated into the permeable gas and the recovered gas by the third gas separation membrane module 32, the target gas concentration contained in the discharged permeable gas is lowered.

In the above description, the mixed gas supplied to the gas mixing units 110 and 210 of each target gas collecting apparatus, that is, the injected gas and the second recovering gas have the same target gas concentration, And is supplied to the gas mixing portion 110 (210) at the same target gas concentration as the injected gas and the second recovered gas. The third SC value (? ₂₃ ) is controlled so that the target gas concentration of the third withdrawn gas coincides with the target gas concentration of the injected gas and the second recovered gas. A second SC value (θ ₁₂₎ (θ ₂₂₎ and a third SC value (θ ₂₃₎ a second number of target gas concentration, and a third number of the gas supplied to the gas mixing section 110, 210, under the control of the As the target gas concentration of the gas coincides with the target gas concentration of the injected gas, the target gas concentration of the mixed gas supplied to the first gas separation membrane modules 130 and 230 of the target gas recovery apparatus is maintained constant, The target gas concentration of the first recovery gas of the first gas separation membrane module 130 (230) can be stably maintained. The third gas separation membrane module 32 includes a third compression tank 31 at the front end of the third gas separation membrane module 32 and a third SC value 32 of the third gas separation membrane module 32 at the rear end of the third gas separation membrane module 32. [ The third SC regulator 33 is also provided.

The third SC value is summarized as Equation 19 below.

(Expression 19)

(θ ₂₃ is the third third SC value of the gas separation membrane module, x ₀ is the target gas concentration, x ₁ in the injection gas is a first target gas first target gas concentrations, α ₂₁ and α ₂₂ for recovering gas of the recovery device is Selectivity of the first gas separation membrane module and the second gas separation membrane module, respectively, of the second target gas recovery device, and? ₂₃ is the selectivity of the third gas separation membrane module)

Next, a highly concentrated target gas recovery method using the gas separation membrane module according to an embodiment of the present invention will be described. The highly concentrated target gas recovery method using the gas separation membrane module according to an embodiment of the present invention proceeds based on the apparatus configuration of FIG. 1, that is, the highly concentrated target gas recovery apparatus using the gas separation membrane module according to an embodiment of the present invention.

First, the target gas concentration (x ₁ ) (x ₂ ) of the first recovered gas of the first gasketing membrane modules 130 and 230 is set in each of the target gas collecting apparatuses, 130) 230 to the target concentration (e ₁₁ ) (e ₂₁ ). The target concentration degrees e ₁₁ and e _{21 of} the first gas separation membrane modules 130 and 230 are calculated through Equations 3 and 4.

(Equation 3) The target concentration (e ₁₁ ) = x ₁ / x ₀

(e ₁₁ is the target concentration of the first gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration of the injected gas, and x ₁ is the target gas concentration of the first recovery gas of the first target gas recovery device)

(Equation 4) Target concentration (e ₂₁ ) = x ₂ / x ₁

(e ₂₁ is the second target gas recovery second gas target concentration of the membrane module is, x ₁ is the first target base target gas concentration, x ₂ of the first number of gas recovery apparatus of the second target gas recovery on the device Target gas concentration of the first recovered gas)

Target concentration of the first gas separation membrane module 130, 230 also (e ₁₁₎ (e ₂₁₎ is in the calculated condition, the first target concentration of the gas separation membrane module 130, 230 also (e ₁₁₎ (e ₂₁₎ to set the SC of claim 1 value (θ ₁₁₎ (θ ₂₁₎ that meet. The first SC value? ₁₁ (? ₂₁ ) is calculated by the following Expression 5 and Expression 6.

(Equation 5)

(θ ₁₁ is in a first gas separation membrane of claim 1, SC value applied to the module, e ₁₁ has a first target gas also the first target concentration of the gas separation membrane module of the harvesting device, x ₀ is injecting gas in the target gas recovery device Target gas concentration,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device)

(Equation 6)

(θ ₂₁ is the second target gas first SC values applied to a first gas separation membrane module of the harvesting device, e ₂₁ of the second target base target enrichment, x ₁ of the first gas separation membrane module of the recovery device is injected into the gas ( The target gas concentration in the first recovery gas of the first target gas recovery device),? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device)

The second SC value? ₁₂ (? ₂₂ ) is set together with the first SC value? ₁₁ (? ₂₁ ). Wherein the second SC value (θ ₁₂₎ (θ ₂₂₎ has a second recovery gas in the target gas concentration and the match expression 9 and expression 11 under conditions that satisfy the target gas concentration in the injected gas (x ₀ or x ₁₎ Lt; / RTI > All. In addition to the setting of the first SC value ₁₁ (θ ₁₁ ) (θ ₂₁ ) and the second SC value ₁₂ (θ ₂₂ ), in order to keep the target gas concentration in the first recovered gas constant, The optimal membrane areas of the modules 130 and 230 and the second gasketing membrane modules 160 and 260 may be designed by using the equations 12 to 15, respectively.

(Equation 10)

(? ₁₂ is the second SC value of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas,? ₁₁ and? ₁₂ are the first gas separation membrane module of the first target gas recovery device and the second gas separation membrane Selectivity of module)

(Expression 12)

(θ ₂₂ is the second second SC value of the target gas recovering apparatus, y ₂ is the second target base target gas concentration, x ₁ of the first permeate gas of the recovery device is the target gas concentration in the injected gas, α ₂₁ and α ₂₂ Are selectivity diagrams of the first gas separation membrane module and the second gas separation membrane module of the second target gas recovery device, respectively)

That sets the following, the third SC value of the third gas separation membrane module (32) to match the target gas concentration (x ₀₎ of the injection gas concentration in the target substrate 3 recovered gas (θ _23). The third SC value (? ₂₃ ) of the third gas separation membrane module (32) is calculated by the following Expression (16).

(Expression 19)

(θ ₂₃ is the third third SC value of the gas separation membrane module, x ₀ is the target gas concentration, x ₁ in the injection gas is a first target gas first target gas concentrations, α ₂₁ and α ₂₂ for recovering gas of the recovery device is Selectivity of the first gas separation membrane module and the second gas separation membrane module, respectively, of the second target gas recovery device, and? ₂₃ is the selectivity of the third gas separation membrane module)

As described above, the target enrichment degree e ₁₁ (e ₂₁ ), the first SC value ₁₁ (θ ₂₁ ), the second SC value ₁₂ (θ ₁₂ ) of the first gasketing membrane modules 130 and 230 _22), the third SC value (θ _23), a high concentration in a set state, the first target gas recovering apparatus 100, the second target base recovery unit 200 and the target gas using the three gas separation membrane modules (32) The collection process proceeds.

Specifically, waste gas containing an injection gas containing the target gas, for example, SF _6, is supplied from the injection gas supply unit 10 to the gas mixing unit 110 of the first target gas recovery apparatus 100, The units 110 and 210 mix the injected gas with the second recovered gas recovered by the second gas separation membrane module 160 and the third recovered gas recovered by the third gas separation membrane module 32, , The second recovered gas and the third recovered gas are supplied to the first compression tank (120). Only the injection gas is supplied to the first compression tank 120 because the second recovered gas and the third recovered gas are not supplied to the gas mixing unit 110 during the initial operation.

The first compression tank 120 compresses the mixed gas to a predetermined pressure and injects the mixed gas into the first gas separation membrane module 130. It is necessary to vary the supply pressure of the mixed gas injected into the first gasketing membrane module 130 in accordance with the change in the flow rate of the injected gas in order to cope with the change in flow rate of the injected gas. (P) is set as shown in Equation 17 below. The supply pressure of the second compression tank 150, which will be described later, is also set equal to the supply pressure of the first compression tank 120.

(Equation 17)

(P is the feed pressure, f is a real-time rate of change injection gas, f ₀ is the flow rate of the initial fill gas, P ₀ is the first compression tank and the second compression tank of the first compression tank and the second compression tank in which real-time settings Of the initial supply pressure)

The mixed gas injected into the first gas separation membrane module 130 at the constant supply pressure P is separated into the first permeation gas and the first recovery gas by the first gas separation membrane module 130. At this time, the flow rate of the first permeable gas and the flow rate of the first recovered gas are determined by the set first SC value (? ₁₁ ). The first recovered gas is collected at one end of the first gas separation membrane module 130 and is supplied to the gas mixture part 210 of the second target gas recovery device 200 as an injector.

The first permeable gas separated by the first gas separation membrane module 130 is supplied to the second compression tank 150 and the second compression tank 150 is supplied with the same supply pressure as the supply pressure of the first compression tank 120. [ And the first permeable gas is injected into the second gas separation membrane module 160 under pressure.

The second gas separation membrane module 160 separates the injected first transparent gas into a second transparent gas and a second recovered gas. At this time, the flow rate of the second permeable gas and the flow rate of the second recovered gas are determined by the set second SC value (? ₂ ).

The second recovered gas separated by the second gas separation membrane module 160 is supplied to the gas mixing unit 110. The gas mixing unit 110 separates the second recovered gas and the injected gas, . Next, the mixed gas of the second recovered gas, the third recovered gas and the injected gas is supplied to the first gas separation membrane module 130 via the first compression tank 120, and the target gas recovery process is repeated as described above It proceeds.

Meanwhile, the first recovery gas recovered by the first gas separation membrane module 130 of the first target gas recovery apparatus 100 is supplied to the gas mixture unit 210 of the second target gas recovery apparatus 200 as an injector body . Second target gas recovering apparatus 200 is recovered process within will be presented the same as the number of times the process of the first target gas recovering apparatus 100, the target concentration of the first gas separation membrane module 230 is also (e _21), Only the first SC value (? ₂₁ ) and the second SC value (? ₂₂ ) are applied differently.

When the target gas recovery process is performed by the first target gas recovery device 100 and the second target gas recovery device 200, the second gas recovery device 200 of the second target gas recovery device 200 2 permeable gas is supplied to the injector body to the third gas separation membrane module 32 and the third gas separation membrane module 32 separates the second transmissive gas into the third recover gas and the third transmissive gas. At this time, the flow rate of the third recovered gas and the flow rate of the third permeable gas are determined by the set third SC value (? ₂₃ ).

The third recovered gas separated by the third gas separation membrane module 32 is supplied to the gas mixing unit 110 of the first target gas recovery apparatus 100 and the gas mixture unit 110 supplies the gas, The second recovered gas and the third recovered gas are mixed. Next, the mixed gas of the second recovered gas, the third recovered gas and the injected gas is supplied to the first gas separation membrane module 130 via the first compression tank 120, and the target gas recovery process is repeated as described above It proceeds.

In this manner, the second SC value (? ₁₂ ) (? (?)) Is calculated so that the second recovered gas and the third recovered gas supplied to the gas mixing units 110 and 210 of each target gas- ₂₂ and the third SC value ₂₃ are controlled so that the target gas concentration in the first recovery gas of the first gas separation membrane module 130 or 230 of each target gas recovery apparatus can be maintained constant .

10: Injection gas supply unit 100: First target gas recovery unit
110, 210: gas mixer 120, 220: first compression tank
130, 230: first gas separation membrane module 140, 240: first SC regulator
150, 250: second compression tank 160, 350: second gas separation membrane module
170, 270: Second SC regulator

Claims (17)

And a plurality of target gas recovery devices connected in series,
Wherein the target gas-
A gas mixing section for mixing the injected gas, the second recovered gas and the third recovered gas;
A first gas separation membrane module for separating a mixed gas of an injected gas, a second recovered gas and a third recovered gas into a first permeated gas and a first recovered gas in accordance with a set first SC value; And
And a second gas separation membrane module for separating the first transparent gas into a second transparent gas and a second recover gas in accordance with a set second SC value,
And a third gas separation membrane module for separating the second permeable gas of the second gas separation membrane module of the target gas recovery device at the downstream end into the third recovered gas and the third permeable gas in accordance with the set third SC value,
The second recovery gas and the third recovery gas are supplied to the gas mixing unit,
The second SC value and the third SC value are set so that the target gas concentration of the second recovered gas and the target gas concentration of the third recovered gas are matched with the target gas concentration of the injected gas,
Wherein the plurality of target gas collecting apparatuses include a first target gas collecting apparatus and a second target gas collecting apparatus connected in series, wherein an injection gas containing a target gas to be recovered is disposed in front of the first target gas collecting apparatus Further comprising an injecting gas supply unit for supplying the gas to the gas mixing unit of the first target gas collecting apparatus.
The apparatus of claim 1, wherein the second SC value (? ₁₂ ) of the second gas separation membrane module of the first target gas recovery device is calculated by the following equation.
(expression)

(? ₁₂ is the second SC value of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas,? ₁₁ and? ₁₂ are the first gas separation membrane module of the first target gas recovery device and the second gas separation membrane Selectivity of module)
The apparatus of claim 1, wherein the second SC value (? ₂₂ ) of the second gas separation membrane module of the second target gas recovery device is calculated through the following equation.
(expression)

( ₂₂ is the second SC value of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas, and? ₂₁ and? ₂₂ are the second gas recovery device's first gas separation membrane module and the second gas separation membrane Selectivity of module)
The apparatus of claim 1, wherein the third SC value (? ₂₃ ) of the third gas separation membrane module is calculated by the following equation.
(expression)

(θ ₂₃ is the third third SC value of the gas separation membrane module, x ₀ is the target gas concentration, x ₁ in the injection gas is a first target gas first target gas concentrations, α ₂₁ and α ₂₂ for recovering gas of the recovery device is Selectivity of the first gas separation membrane module and the second gas separation membrane module, respectively, of the second target gas recovery device, and? ₂₃ is the selectivity of the third gas separation membrane module)
The apparatus of claim 1, wherein the first SC value (? ₁₁ ) of the first gas separation membrane module of the first target gas recovery device is calculated by the following equation.
(expression)

(θ ₁₁ is in a first gas separation membrane of claim 1, SC value applied to the module, e ₁₁ has a first target gas also the first target concentration of the gas separation membrane module of the harvesting device, x ₀ is injecting gas in the target gas recovery device Target gas concentration,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device)
The apparatus of claim 1, wherein the first SC value (? ₂₁ ) of the first gas separation membrane module of the second target gas recovery device is calculated by the following equation.
(expression)

(θ ₂₁ is the second target gas first SC values applied to a first gas separation membrane module of the harvesting device, e ₂₁ of the second target base target enrichment, x ₁ of the first gas separation membrane module of the recovery device is injected into the gas ( The target gas concentration in the first recovery gas of the first target gas recovery device),? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device)
[2] The apparatus of claim 1, further comprising a first compression tank and a second compression tank,
The first compression tank supplies the mixed gas of the injected gas and the second recovered gas to the first gasketing membrane module at a specific supply pressure,
The second compression tank supplies the first permeable gas to the second gas separation membrane module at a specific supply pressure,
Wherein the supply pressure of the first compression tank and the supply pressure of the second compression tank are set equal to each other.
8. The gas recovery system according to claim 7, wherein the supply pressure (P) of the first compression tank and the supply pressure (P) of the second compression tank are calculated by the following equations .
(expression)

(A is the optimum membrane area of the gas separation membrane corresponding to the changed supply pressure, A ₀ is the optimum membrane area of the gas separation membrane corresponding to the reference supply pressure, P ₀ is the reference supply pressure, and P is the changed supply pressure)
The apparatus according to claim 1, further comprising: a first SC regulator for controlling the first permeate flow rate and the first recovered gas flow rate of the first gas separation membrane module by controlling a first SC value of the first gas separation membrane module according to the set target concentration,
Controlling the second SC value of the second gas separation membrane module so that the target gas concentration of the second recovered gas matches the target gas concentration in the injected gas to control the second permeate flow rate and the second recovered gas flow rate of the second gas separation membrane module A second SC regulator,
The third SC value of the third gas separation membrane module is controlled so that the target gas concentration of the third withdrawn gas coincides with the target gas concentration in the injected gas to control the third permeate flow rate and the third withdrawn gas flow rate of the third gas separation membrane module Further comprising a third SC regulator for regenerating the gas.
2. The gas separation membrane module as claimed in claim 1, wherein the membrane areas of the first gas separation membrane module and the second gas separation membrane module of the first target gas recovery device are set through the following equations (1) and (2) Target gas recovery device.
(Equation 1)

(A ₁₁ is the first target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module, P _{B, 11} is the permeability of the first recovered gas of the first target gas recovery device,? ₁₁ is the selectivity of the first gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas, r ₁ is the rate of increase in the flow rate of the mixed gas including the second recovered gas and the third recovered gas as compared with the first injected gas injected into the first gas separation membrane module of the first target gas recovery device , r ₁ is

)
(Equation 2)

(A ₁₂ has a first target second membrane area of the gas separation membrane module for gas recovery apparatus, θ ₁₂ is the second SC value, P _B, of the second gas separation membrane module of the first target gas recovery unit ₁₁ is the first target base P _{B, 12} is the permeability of the second recovered gas of the first target gas collecting device, α ₁₁ is the selectivity of the first gas separator module of the first target gas collecting device, α ₁₂ Is the selectivity of the second gas separation membrane module of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas)
2. The gas separation membrane module according to claim 1, wherein the membrane areas of the first gas separation membrane module and the second gas separation membrane module of the second target gas recovery device are set through the following equations (1) and (2) Target gas recovery device.

(Equation 1)

(A ₂₁ is the second target gas recovery first membrane area of the gas separation membrane module of the apparatus, f ₀ is the flow rate, P ₀ is the first supply pressure of the first compression tank for injecting gas, θ ₁₁ is the first target gas recovery device The first SC value of the first gas separation membrane module,? ₂₁ is the first SC value of the first gas separation membrane module of the second target gas recovery device, P _{B, 21} is the permeability of the first recovery gas of the second target gas recovery device , α ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁

, r ₂ is

)
(Equation 2)

(A ₂₂ is the film area of the second gas separation membrane module of the second target gas recovery device,? ₂₂ is the second SC value of the second gas separation membrane module of the second target gas recovery device, P _B, P _{B, 22} is the permeability of the second recovered gas of the second target gas collecting device,? ₂₁ is the selectivity of the first gas separator module of the second target gas collecting device,? ₂₂ X ₁ is the target gas concentration in the injected gas (the first recovered gas of the first target gas recovery device), and the target gas concentration in the second gas recovery device is the selectivity of the second gas separation membrane module of the second target gas recovery device,
The apparatus of claim 1, wherein the membrane area of the third gas separation membrane module is set through the following equation.
(expression)

(A ₂₃ is the membrane area of the third gas separation membrane module, f ₀ is the flow rate of the injected gas, P ₀ is the initial supply pressure of the first compression tank, and θ ₁₁ is the pressure of the first gas separation membrane module 1, SC value, θ ₂₁ is the second target gas first SC value, θ ₂₂ of the first gas separation membrane module of the recovery device is a second second SC value, θ ₂₃ of the gas separation membrane module of the target gas recovery device of claim 3 is the third SC value of the gas separation membrane module, P _{B, 23} is the permeability of the third recovered gas,? ₂₁ is the selectivity of the first gas separation membrane module of the second target gas recovery device,? ₂₂ is the second target gas recovery device ? ₂₃ is the selectivity of the third gas separation membrane module, x ₁ is the target gas concentration in the injected gas (the first recovery gas of the first target gas recovery device), r ₁ is the selectivity of the second gas separation membrane module

, r ₁₂

)
13. The apparatus according to any one of claims 10 to 12, wherein the first gas separation membrane module of the first target gas recovery device, the second gas separation membrane module of the first target gas recovery device, the first gas separation membrane module of the second target gas recovery device Wherein the membrane area (A) of the separation membrane module, the second gas separation membrane module of the second target gas recovery device, and the third gas separation membrane module is set through the following equation.
(expression)

(A is the optimum membrane area of the gas separation membrane corresponding to the changed supply pressure, A ₀ is the optimum membrane area of the gas separation membrane corresponding to the reference supply pressure, P ₀ is the reference supply pressure, and P is the changed supply pressure)
The method of claim 1, wherein the waste gas to the injected gas including the target gas comprises a waste gas or fluoride gas including SF _6, wherein the target gas is enriched with a gas separation membrane module, characterized in that SF ₆ or fluoride gas Target gas recovery device.
A plurality of target gas collecting devices are connected in series,
The target gas recovery device includes a first gas separation membrane module and a second gas separation membrane module, separating the mixed gas into a first permeation gas and a first recovered gas through a first gas separation membrane module, Separates the first permeable gas of the first gas separation membrane module into a second permeable gas and a second recovered gas,
The third gas separation membrane module separates the second permeation gas of the second gas separation membrane module into the third recovery gas and the third permeation gas, and the injection gas, the second recovery gas, and the third recovery gas are supplied to the first gas separation membrane module And,
The first gas separation membrane module separates the mixed gas of the injected gas, the second recovered gas and the third recovered gas into the first permeated gas and the first recovered gas according to the set first SC value,
The second gas separation membrane module separates the first transparent gas into a second transparent gas and a second gas according to a second SC value,
The third gas separation membrane module separates the second permeable gas into a third permeable gas and a third recovered gas according to a set third SC value,
Wherein the second SC value and the third SC value are set so that the target gas concentration of the second recovered gas and the target gas concentration of the third recovered gas are in agreement with the target gas concentration of the injected gas. Gas recovery method.
The method according to claim 15, wherein the second SC value (? ₁₂ ) of the second gas separation membrane module of the first target gas recovery device is calculated by the following equation (1) And the second SC value (? ₂₂ ) is calculated through the following equation (2).
(Equation 1)

(? ₁₂ is the second SC value of the first target gas recovery device, x ₀ is the target gas concentration in the injected gas,? ₁₁ and? ₁₂ are the first gas separation membrane module of the first target gas recovery device and the second gas separation membrane Selectivity of module)
(Equation 2)

( ₂₂ is the second SC value of the second target gas recovery device, x ₁ is the target gas concentration in the injected gas, and? ₂₁ and? ₂₂ are the second gas recovery device's first gas separation membrane module and the second gas separation membrane Selectivity of module)
16. The method of claim 15, wherein the third SC value (? ₂₃ ) of the third gas separation membrane module is calculated through the following equation.
(expression)

(θ ₂₃ is the third third SC value of the gas separation membrane module, x ₀ is the target gas concentration, x ₁ in the injection gas is a first target gas first target gas concentrations, α ₂₁ and α ₂₂ for recovering gas of the recovery device is Selectivity of the first gas separation membrane module and the second gas separation membrane module, respectively, of the second target gas recovery device, and? ₂₃ is the selectivity of the third gas separation membrane module)

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