JP2013212474A - Gas separation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas separation apparatus capable of suppressing an increase in equipment scale or reducing equipment costs and operation costs, in a gas separation apparatus separating target gas from processed gas through generation of a hydrate.SOLUTION: A gas separation apparatus comprises: a first gas collection discharge device receiving processed gas; and a second gas collection discharge device receiving the gas discharged by the first gas collection discharge device. The first and second gas collection discharge devices each have: a hydrate generation device bringing aqueous solution of a guest compound generating a hydrate into contact with the gas, and performing cooling, thereby generating the hydrate in which the gas is collected; and a hydrate melting device heating and melting the hydrate generated in the hydrate generation device to thereby release the gas. The hydrate generation device of the second gas collection discharge device has smaller hydrate generation capability than the hydrate generation device of the first gas collection discharge device.

Description

  The present invention relates to a gas separation device that separates a target gas (hereinafter referred to as “target gas”) from a gas to be treated through the formation of a hydrate, and more specifically, suppresses the expansion of the facility scale or the facility and operating costs. It is related with the gas separation apparatus which can reduce.

  In this specification, the meaning or interpretation of terms is as follows. The meaning or interpretation of these terms does not preclude the technical scope of the present invention from reaching an equivalent scope.

  (1) “Hydrate” is an abbreviation for clathrate hydrate. Other molecules or compounds called guest substances in tunnel-type, layer-like, network-like or cage-like structures (inclusion lattices) formed by molecules or compounds called hosts or host substances (ie, host molecules or host compounds) A substance formed and formed by entering (or guest molecule or guest compound) is referred to as an inclusion compound. Examples of guest compounds include quaternary ammonium salts typified by alkyl ammonium salts such as tetra-n-butylammonium salt, tetra-isopentylammonium salt, tri-n-butyl-pentylammonium salt, alkylphosphonium salts, and alkylsulfonium salts. is there. Examples of host molecules include water and cyclodextrin. An inclusion compound in which the host molecule is water is an inclusion hydrate. The “hydrate” in the present invention includes quasi-clathrate hydrate.

  (2) An aqueous solution of a hydrate guest molecule, more specifically, an aqueous solution containing one or more guest compounds as a solute and water as a solvent forms a hydrate. In the present invention, “an aqueous solution of a guest compound that forms a hydrate” refers to an aqueous solution containing a guest compound that forms a hydrate upon cooling.

  (3) “Hydrate slurry” refers to a hydrate dispersed or suspended in an aqueous solution or aqueous solvent of the guest compound to form a slurry.

  As a technique for collecting and separating the target gas from the gas to be treated by generating a hydrate containing the target gas, typical examples of the hydrate include gas hydrates having guest molecules as the gas, For example, it is a hydrate containing a quaternary ammonium salt as a guest molecule, and a technique for separating the gas through the formation of such a hydrate has been studied (for example, see Patent Documents 1 to 4).

In these techniques, when the concentration of the target gas in the gas to be treated is low, or when a high concentration of the target gas in the gas to be separated and recovered is desired, a separation operation by hydrate formation is performed. It is supposed to be done in two stages.

JP 2006-282403 A JP 2003-138281 A JP 2010-2055 A JP 2011-231002 A

  In the gas separation device that performs the separation operation by hydrate generation in two stages, the concentration of the target gas in the gas separated from the gas to be treated by the first separation operation is increased, and the gas whose concentration has increased The concentration of the target gas is further increased by the second separation operation. If the hydrate generating capacity of the hydrate generator that performs the separation operation of the first stage and the second stage is the same, the processing capacity of the second stage hydrate generator is excessive with respect to the gas to be processed. Therefore, it is useless, and consequently hinders reduction in equipment costs and operating costs.

  This invention is made | formed in view of the above problems, and it aims at providing the gas separation apparatus which can suppress the expansion of an installation scale or can reduce an installation cost and an operating cost.

  In order to solve the above-described problem, one aspect of the present invention is a gas separation device that separates a target gas from a gas to be processed using a hydrate, and a first gas collection and discharge device that receives the gas to be processed; And a second gas collection / release device for receiving the gas emitted by the first gas collection / release device, wherein the first gas collection / release device and the second gas collection / release device are respectively The aqueous solution of the guest compound that forms a hydrate is brought into contact with a gas and cooled, thereby generating a hydrate that collects the gas, and the hydrate generating device that generates the hydrate. A hydrate melting device that heats and melts the hydrate and thereby releases the gas, and the hydrate generating device of the second gas collection and release device is the first gas collection and release Compared to the hydrate generation device of the device, the hydrate generation capacity is small. Providing a gas separation apparatus according to.

  In the gas separation apparatus configured as described above, the hydrate generating apparatus is a hydrate generating pipeline apparatus configured with a double-tube heat exchanger, and an aqueous solution of a guest compound and an inner pipe A hydrate generation tube of the second gas collection and discharge device is used for generating a hydrate by circulating a mixed fluid of a gas to be treated and flowing a cooling medium through an outer tube to cool the mixed fluid. Compared with the hydrate generation line device of the first gas collection and release device, the line device has a short generation line length and a small heat transfer area, and the internal pipe cross-sectional area of the generation line is large and mixed. Low flow rate of fluid, low feed rate of aqueous solution pump, low supply flow rate of mixed fluid, large cross-sectional area of cooling medium flow path of production pipe, low flow rate of cooling medium, cooling medium supply pump The amount of liquid to be fed should be low, the cooling medium supply flow rate should be low, and the type of cooling medium Further to that, to change the supply temperature of the chilling medium, changing the concentration of the aqueous solution by at least one of, it is possible to reduce the heat exchange capacity.

  Another aspect of the present invention is a gas separation device for separating a target gas from a gas to be treated using a hydrate, comprising a plurality of gas collection and discharge devices arranged in series. The gas collection / release device accepts the gas to be treated, the gas collection / release devices after the second stage accept the gas released by the gas collection / release device of the previous stage, and the gas collection / release devices of the plurality of stages are: The aqueous solution of the guest compound that produces a hydrate is brought into contact with the gas and cooled, thereby producing a hydrate that collects the gas, and a hydrate production device that produces the hydrate. A hydrate melting device that heats and melts the hydrate that has been heated and thereby releases the gas. Compared to the hydrate generator of the release device, the hydrate generation capacity is small. Providing a gas separation apparatus according to.

  ADVANTAGE OF THE INVENTION According to this invention, it is a gas separation apparatus which performs the separation operation by hydrate production | generation in two steps, Comprising: The gas separation apparatus which can suppress the expansion of an installation scale or can reduce an installation cost and an operating cost can be provided.

It is a figure which shows the gas separation apparatus which concerns on one Embodiment of this invention.

  Hereinafter, the present invention will be described in detail according to various embodiments of the present invention. The technical scope of the present invention is not limited by these embodiments, and can be implemented in various forms without changing the gist of the invention. Further, the technical scope of the present invention extends to an equivalent range.

<Embodiment>
FIG. 1 is a system diagram showing a gas separation device according to an embodiment of the present invention.

The gas separation device shown in FIG. 1 receives a gas to be processed A containing a target gas, generates a hydrate containing the target gas, collects the target gas from the gas to be processed A, and then heats the hydrate. A first gas collection and release device 100 that melts and releases the target gas from the hydrate to obtain a concentrated gas B with an increased concentration of the target gas;
The concentrated gas B processed by the first gas collection and release device 100 is received, a hydrate containing the target gas is generated, the target gas is collected from the concentrated gas B, and then the hydrate is heated and melted. And a second gas collection and release device 200 that releases the target gas from the hydrate and obtains the highly concentrated gas C in which the concentration of the target gas is further increased.

The first gas collecting / releasing device 100 and the second gas collecting / releasing device 200 use an aqueous solution D or E of a guest compound that generates a hydrate (hereinafter sometimes simply referred to as “aqueous solution”) as a target gas. A hydrate containing a target gas is produced by contacting and cooling to produce a hydrate that takes in the target gas molecules into the voids in the inclusion lattice, thereby collecting the target gas. Generators 101 and 201;
The hydrate generating apparatuses 101 and 201 are respectively provided with hydrate melting apparatuses 102 and 202 that heat and melt the hydrates generated to release the target gas.

  In the hydrate generating apparatuses 101 and 201, a hydrate slurry in which the hydrate is dispersed or suspended in the aqueous solution is generated.

<First gas collection and release device 100>
The first gas collection and release device 100 increases the pressure of the gas A to be processed including the target gas and supplies the pressure to the mixer 104.
An aqueous solution pump 106 for supplying an aqueous solution of a guest compound that forms a hydrate to the mixer 104 from the aqueous solution storage tank 105;
The mixer 104 for mixing the gas to be processed into the aqueous solution, and the mixed fluid in which the gas to be processed A and the aqueous solution D are mixed by the mixer 104 are received, cooled, and the target gas molecules are taken into the voids in the inclusion lattice. Hydrate generating device (generation line) 101 for generating a hydrate and collecting a target gas,
A hydrate slurry in which a hydrate produced by a hydrate producing apparatus is dispersed or suspended in an aqueous solution and a residual gas in a gas to be treated that is not taken into the hydrate are received and separated to separate them. Gas separator 107,
A hydrate slurry pump 108 for supplying the hydrate slurry from which the residual gas 111 has been separated by the residual gas separator 107 to the hydrate melting apparatus 102;
A hydrate melting apparatus 102 for heating the hydrate slurry, melting the hydrate, and releasing a target gas taken in from the hydrate;
A target gas separator 109 that receives an aqueous solution in which a hydrate has been melted by the hydrate melting apparatus 102 and a target gas, separates them, and obtains a concentrated gas B with an increased concentration of the target gas, and a target gas separator Aqueous solution storage tank 105 for storing the aqueous solution D separated in 109
Is provided.

<Second gas collection / release device 200>
The configuration is substantially the same as that of the first gas collection / release device 100.

  Concentrated gas B whose concentration of the target gas has been increased by the first gas collection / release device 100 is supplied to the mixer 204.

  The target gas separator 209 obtains a highly concentrated gas C in which the concentration of the target gas is further increased.

  It is preferable that the hydrate generation device 201 of the second gas collection / release device 200 has a lower hydrate generation capability than the hydrate generation device 101 of the first gas collection / release device 100. .

Here, the hydrate production ability refers to the amount of hydrate produced per unit time.

  The hydrate generating device 201 of the second gas collection / release device 200 is supplied with a mixed fluid of the concentrated gas B and the aqueous solution E whose concentration of the target gas is increased by the first gas collection / release device 100, A hydrate containing the target gas is produced. The concentration of the target gas in the hydrate generating device 201 of the second gas collection / release device 200 is higher than that in the case where the hydrate is generated in the hydrate generation device 101 of the first gas collection / release device 100. Since the unreacted residual gas is removed from the gas to be treated and the amount of gas to be treated is reduced, the hydrate generating device 101 of the first gas collection and release device 100 is reduced. It is not necessary to have the same hydrate production capacity as in the case of hydration production equipment with a moderate hydrate production capacity, thereby suppressing the expansion of equipment scale and reducing equipment costs and operating costs. it can.

  Further, as the hydrate generation device 201 of the second gas collection / release device 200 is changed to a hydrate generation device having an appropriate hydrate generation capability, the hydration of the second gas collection / release device 200 is performed. It is preferable that the object melting apparatus 202 has a lower hydrate melting ability than the hydrate melting apparatus 102 of the first gas collection and release apparatus 100. Thereby, expansion of an equipment scale can be suppressed and an installation cost and an operating cost can be reduced. Here, the hydrate decomposition ability refers to the amount of hydrate decomposition per unit time.

  The hydrate generating device 201 and the hydrate melting device 202 of the second gas collection / release device 200 are compared with those of the first gas collection / release device 100 in terms of hydrate generation capability and hydrate melting. As the capacity is low, the booster 203, the aqueous solution pump 206, the mixer 204, the residual gas separator 207, and the target gas separator 209 can each have a low processing capacity, Equipment costs and operating costs can be reduced.

  Hereinafter, each of these devices will be described.

<First gas collection and release device 100>
[Mixer 104]
An aqueous solution pump 106 receives supply of an aqueous solution D from an aqueous solution storage tank 105, which will be described later.

  The supply of the gas A to be treated to the aqueous solution D is relative, and this applies to the case where the gas A is released toward the aqueous solution D and the case where the aqueous solution D is released toward the gas A to be treated. . A typical example of the former is bubbling of the gas A from outside the region to the region where the aqueous solution D exists, and in that case, the smaller the bubble particle size, the better. As one aspect of the mixer 104 that realizes this, the mixer 104 is composed of a tank filled with the aqueous solution D, and the gas is dispersed in the aqueous solution as fine bubbles. In this case, it is preferable that the bubble diameter is small so that the gas-liquid contact area can be increased.

  A typical example of the latter case where the aqueous solution D is released toward the gas A to be treated is spraying of the aqueous solution D from outside the region to the region where the gas A exists. As an aspect of the mixer 104 that realizes this, there is a type in which the aqueous solution D is sprayed by a spray nozzle in a container filled with the gas A and brought into contact with the gas A, and the gas A is dissolved in the aqueous solution D.

  In either case of the former and the latter, it is preferable that the supply of the gas A to the aqueous solution D is performed by a technique for further increasing the contact area between the gas A and the aqueous solution D.

  Further, a line mixer may be used as the mixer 104. In the line mixer, the aqueous solution D is supplied to the cylindrical body, and a swirl flow is formed by a blade body or the like provided on the inner surface. It is crushed and the aqueous solution D and the gas A to be processed are mixed.

  After the gas A to be treated is mixed with the aqueous solution D by the mixer 104, the mixed fluid is sent to the hydrate generator 101.

[Hydrate generator 101]
The hydrate generating apparatus 101 has a cooling function, generates a hydrate containing the target gas by cooling the mixed fluid of the aqueous solution D and the gas to be processed A mixed in the mixer 104, and the water. A hydrate slurry is produced in which a hydrate is dispersed or suspended in an aqueous solution. As a cooling function, it is preferable to provide a heat exchange function for supplying and cooling the cooling medium 110.

  In the embodiment of FIG. 1, the hydrate generating device 101 is a generating pipe composed of a double-pipe heat exchanger, and a mixed fluid of an aqueous solution D and a gas to be processed A is circulated through the inner pipe, and the outer pipe Then, the cooling medium 110 is circulated to cool the mixed fluid to form a hydrate. Further, the hydrate generator 101 may be a shell and tube heat exchanger, and the mixed fluid is circulated in the heat transfer tube, the cooling medium 110 is circulated in the shell, and the peripheral surface in the heat transfer tube is interposed. Thus, cooling may be performed by heat exchange with the cooling medium 110.

  In addition, in the hydrate generating apparatus 101, there is a remaining gas that is not included in the hydrate and is not collected in the gas A to be treated, and this is water together with the hydrate slurry as an unreacted residual gas. It is extracted from the hydrate generator 101 and separated from the hydrate slurry by a separator 107 described later.

  In the hydrate production | generation apparatus 101, it is preferable that the cooling temperature which cools aqueous solution shall be higher than 0 degreeC. That is, the temperature of the slurry to be generated is set to a temperature higher than 0 ° C. If the cooling temperature is cooled to a temperature higher than 0 ° C., a cooling tower that exchanges heat between the refrigerator or the outside air and cold water can be used as an apparatus used to supply the refrigerant. A cold medium 110 can be supplied. In particular, when tetraisopentylammonium bromide (TiPAB), which is one of the quaternary ammonium salts, is used as a guest molecule, hydrates can be generated at 15 ° C or higher, so the thermal energy of the outside air can be used. Therefore, a more economical method can be selected.

[Residual gas separator 107]
The residual gas separator 107 receives supply of the hydrate slurry and the unreacted residual gas from the hydrate generator 101 and separates the unreacted residual gas 111.

  The form of the residual gas separator 107 is arbitrary. For example, a decanter, a cyclone separator, a centrifugal separator, or the like can be used, but in order to minimize the mixing of slurry droplets into the separated residual gas 111, For example, it is desirable to use a collision separation type mist separator together.

  The hydrate slurry from which the residual gas 111 has been separated by the residual gas separator 107 is supplied to the hydrate melting apparatus 102 by the hydrate slurry pump 108.

<Hydrate melting apparatus 102>
The hydrate melting apparatus 102 has a heating function, introduces a hydrate slurry from which the residual gas 111 has been separated by the residual gas separator 107, heats the hydrate slurry, melts the hydrate, and forms an aqueous solution. And the target gas collected in the hydrate is released. As a heating function, it is preferable to provide a heat exchanger that supplies and heats a heating medium.

  A double tube heat exchanger having the same structure as that of the hydrate generator 101 may be used, and the heating medium 113 may be supplied instead of the cooling medium 110.

  The gas discharged from the hydrate melting apparatus 102 is a mixture of the target gas released from the hydrate and the remaining residual gas, and is a concentrated gas whose concentration of the target gas is higher than that of the gas to be processed. It has become.

[Target gas separator 109]
The mixed fluid composed of the concentrated gas of the target gas and the aqueous solution is introduced into the target gas separator 109 and separated into the aqueous solution D and the concentrated gas B of the target gas, and the aqueous solution D is sent to the aqueous solution storage tank 105 by the aqueous solution pump 112. The separated concentrated gas B of the target gas is introduced into the second gas collection / release device 200.

  The aqueous solution D stored in the aqueous solution storage tank 105 is supplied to the mixer 104 by the aqueous solution pump 106.

  The form of the target gas separator 109 is arbitrary. For example, a decanter, a cyclone separator, a centrifuge, or the like can be used, but mixing of the slurry droplets into the concentrated gas of the separated target gas is minimized. For this reason, for example, it is desirable to use a collision separation type mist separator together.

<Second gas collection / release device 200>
Each device has substantially the same configuration as the first gas collection / release device 100.

  A concentrated gas B whose concentration of the target gas has been increased by the first gas collection / release device 100 is supplied to the mixer 204.

  The target gas separator 209 discharges the highly concentrated target gas C having a higher target gas concentration.

  The hydrate generation device 201 of the second gas collection / release device 200 has a lower hydrate generation capability than the hydrate generation device 101 of the first gas collection / release device 100.

  The hydrate production capacity of the hydrate production device 201 is greatly affected by the heat exchange capacity between the mixed fluid of the aqueous solution E and the concentrated gas B and the cooling medium 210. By reducing the heat exchange capability between the mixed fluid and the cooling medium 210, the hydrate generation capability of the hydrate generator 201 can be reduced.

In particular,
Reducing the flow rate of at least one of the mixed fluid flowing through the hydrate generating device 201 and the cooling medium 210;
Reducing the heat transfer area,
Changing the type of the cooling medium 210;
Changing the supply temperature of the cooling medium 210;
The heat exchange capacity can be lowered by at least one of changing the concentration of the aqueous solution E.

In the case where the hydrate generating device 101 and the hydrate generating device 201 are generation pipes configured by a double-tube heat exchanger, the hydrate generation pipe of the second gas collection / release device 200 Is
Compared to the hydrate production pipeline of the first gas collection and release device 100, the production pipeline length is short and the heat transfer area is small,
The inner pipe cross-sectional area of the production pipe is large and the flow rate of the mixed fluid is low.
The aqueous solution pump 206 has a low liquid feeding amount, the supply flow rate of the mixed fluid is low,
The cross-sectional area of the cooling medium passage of the production pipe is large, and the flow rate of the cooling medium 210 is low,
The cooling medium supply pump has a low liquid feeding amount, the supply flow rate of the cooling medium 210 is low,
Changing the type of the cooling medium 210;
Changing the supply temperature of the cooling medium 210;
The heat exchange capacity is lowered by at least one of changing the concentration of the aqueous solution E.

  The hydrate generation device 201 of the second gas collection / release device 200 is assumed to have a lower hydrate generation capability than the hydrate generation device 101 of the first gas collection / release device 100, and appropriate water. By using a hydrate generating device with a hydrate generating ability, it is possible to suppress the expansion of the facility scale and to reduce the facility cost and the operating cost.

  As the hydrate generating device 201 of the second gas collecting / releasing device 200 is changed to a hydrate generating device having an appropriate hydrate generating capacity, the hydrate melting of the second gas collecting / releasing device 200 is performed. The device 202 has a lower hydrate melting ability than the hydrate melting device 102 of the first gas collection and release device 100.

  The hydrate melting capacity of the hydrate melting apparatus 202 is greatly affected by the heat exchange capacity between the hydrate slurry and the heating medium 213. By reducing the heat exchange capacity between the hydrate slurry and the heating medium 213, the hydrate melting capacity of the hydrate melting apparatus 202 can be lowered.

In particular,
Reducing the flow rate of at least one of the hydrate slurry and the heating medium 213 flowing through the hydrate melting apparatus 202;
Reducing the heat transfer area,
Changing the type of heating medium 213;
Changing the supply temperature of the heating medium 213;
The heat exchange capacity can be lowered by at least one of changing the concentration of the hydrate slurry.

In the case where the hydrate melting apparatus 102 and the hydrate melting apparatus 202 are melting pipes composed of a double-tube heat exchanger, the hydrate melting pipe of the second gas collection / release apparatus 200 Is
Compared to the hydrate melting line of the first gas collection and release device 100, the melting line length is short and the heat transfer area is small,
The inner pipe cross-sectional area of the melting pipe is large and the flow rate of the hydrate slurry is low,
The hydrate slurry pump 208 has a low liquid feeding amount, and the supply flow rate of the hydrate slurry is low.
The heating medium channel cross-sectional area of the melting pipe is large, and the flow rate of the heating medium 213 is low,
The heating medium supply pump has a low liquid feeding amount, the supply flow rate of the heating medium 213 is low,
Changing the type of heating medium 213;
Changing the supply temperature of the heating medium 213;
The heat exchange capacity is lowered by at least one of changing the concentration of the hydrate slurry.

  The hydrate melting device 202 of the second gas collection / release device 200 has a lower hydrate melting ability than the hydrate melting device 102 of the first gas collection / release device 100, and has an appropriate water content. By using a hydrate melting apparatus with a Japanese melting ability, it is possible to suppress the expansion of the facility scale and to reduce the facility cost and the operating cost.

<Gas separation method>
A method for separating the target gas from the gas A to be processed by the gas separation apparatus configured as described above will be described.

  First, the target gas A containing the target gas, which is a component for collection, is supplied to the first gas collection / release device 100 to obtain the concentrated gas B of the target gas, and the concentrated gas B is used as the second gas. The target gas C supplied to the collection / release device 200 and concentrated to a desired concentration is separated and obtained.

  The gas A to be treated is introduced into the first gas collection / release device 100, pressurized by the booster 103, and mixed with the aqueous solution D by the mixer 104. After the gas A to be processed is mixed with the aqueous solution D by the mixer 104 to form a mixed fluid, the mixed fluid is sent to the hydrate generating device 101. In the hydrate generating apparatus 101, the mixed fluid is cooled by heat exchange with the cooling medium 110 to generate a hydrate containing the target gas, the target gas is collected, and the hydrate is dispersed or suspended in the aqueous solution. A cloudy hydrate slurry is produced.

  The hydrate slurry generated by the hydrate generator 101 and the unreacted residual gas are supplied to the residual gas separator 107, and the hydrate slurry and the unreacted residual gas 111 are separated. The separated hydrate slurry is introduced into the hydrate melting apparatus 102. When the target gas remains in the separated residual gas 111, for example, the separated residual gas 111 is recirculated and joined to the gas to be processed until the remaining amount becomes a certain amount or less, and mixed. Can be supplied to the vessel 104.

  The hydrate slurry separated from the residual gas 111 is introduced into the hydrate melting apparatus 102 and heated by heat exchange with the heating medium 113. By this heating, the hydrate is melted, and the target gas collected in the hydrate is released. By releasing the target gas, a mixed fluid composed of the concentrated gas and the aqueous solution in which the concentration of the target gas is increased in the hydrate melting apparatus 102 is generated. This mixed fluid is introduced into the target gas separator 109 and separated into the aqueous solution D and the concentrated gas B. The separated aqueous solution D is sent to the aqueous solution storage tank 105 and circulated and supplied to the mixer 104. The separated concentrated gas B is introduced into the second gas collection / release device 200.

  In the second gas collection / release device 200, the concentrated gas B pressurized by the pressure booster 203 is introduced into the mixer 204 and mixed with the aqueous solution E. After the concentrated gas B is mixed with the aqueous solution E by the mixer 204 to form a mixed fluid, the mixed fluid is sent to the hydrate generator 201. In the hydrate generator 201, the mixed fluid is cooled by heat exchange with the cooling medium 210 to generate a hydrate containing the target gas, and the hydrate is dispersed or suspended in an aqueous solution. A slurry is produced.

  The hydrate slurry and unreacted residual gas generated by the hydrate generator 201 are supplied to the residual gas separator 207, and the hydrate slurry and unreacted residual gas 211 are separated. The separated hydrate slurry is introduced into the hydrate melting apparatus 202.

  The hydrate slurry separated from the residual gas 211 is introduced into the hydrate melting device 202 and heated by heat exchange with the heating medium 213. By this heating, the hydrate is melted, and the target gas collected in the hydrate is released. When the target gas is released, a mixed fluid composed of a highly concentrated gas whose concentration of the target gas is further increased and an aqueous solution is generated in the hydrate melting apparatus 202. This mixed fluid is introduced into the target gas separator 209 and separated into the aqueous solution E and the highly concentrated gas C. The separated aqueous solution E is sent to the aqueous solution storage tank 205 and circulated and supplied to the mixer 204. The separated highly concentrated gas C is stored or introduced into the next process.

  Thus, the target gas can be separated from the gas A to be treated, and the hydrate generating device 201 and the hydrate melting device 202 of the second gas collection and release device 200 are the same as those of the first gas collection and release device 100. By making the hydrate generation ability and the hydrate melting ability low as compared with the above, the expansion of the equipment scale can be suppressed, and the equipment cost and the operation cost can be reduced.

  In the above embodiment, gas separation is performed by providing the gas collection / release device in two stages. However, by providing the gas collection / release apparatus in three or more stages, the target gas concentrated to a higher concentration is separated. be able to.

  DESCRIPTION OF SYMBOLS 100 ... 1st gas collection-release apparatus, 101,201 ... Hydrate production | generation apparatus, 102,202 ... Hydrate melt | dissolution apparatus, 103,203 ... Booster, 104,204 ... Mixer, 105,205 ... Aqueous solution Storage tank, 106, 112, 206, 212 ... aqueous solution pump, 107, 207 ... residual gas separator, 108, 208 ... hydrate slurry pump, 109, 209 ... target gas separator, 110, 210 ... cold medium, 111, 211 ... residual gas, 113,213 ... heating medium, 200 ... second gas collection / release device, A ... gas to be treated, B ... concentrated gas, C ... highly concentrated target gas, D, E ... aqueous solution.

Claims (3)

A gas separation device for separating a target gas from a gas to be treated using a hydrate,
A first gas collection and release device for receiving the gas to be treated;
A second gas collection / release device for receiving the gas emitted by the first gas collection / release device,
The first gas collection / release device and the second gas collection / release device are respectively
A hydrate generator for generating a hydrate by bringing an aqueous solution of a guest compound that generates a hydrate into contact with a gas and cooling it, thereby collecting the gas;
A hydrate melting device that heats and melts the hydrate produced in the hydrate production device, thereby releasing gas.
The hydrate generating device of the second gas collecting / releasing device has a smaller hydrate generating ability than the hydrate generating device of the first gas collecting / releasing device. .   The hydrate generating device is a hydrate generating conduit device constituted by a double tube heat exchanger, and a mixed fluid of an aqueous solution of a guest compound and a gas to be treated is circulated through an inner tube, and an outer tube A cooling medium is circulated to cool the mixed fluid to generate a hydrate, and the hydrate generation pipeline device of the second gas collection and release device is the first gas collection and release Compared to the hydrate production line device of the device, the production line length is short and the heat transfer area is small, the inner pipe cross-sectional area of the production line is large and the flow rate of the mixed fluid is low, and the aqueous solution pump is fed The supply flow rate of the mixed fluid is low, the cross-sectional area of the cooling medium flow passage in the production pipe is large, the flow rate of the cooling medium is low, and the cooling medium supply pump is set to have a low liquid feed rate to supply the cooling medium. Low flow rate, changing the type of cooling medium, changing the supply temperature of the cooling medium , Changing the concentration of the aqueous solution by at least one of a gas separation apparatus according to claim 1, characterized in that it is adapted to lower the heat exchange capacity. A gas separation device for separating a target gas from a gas to be treated using a hydrate,
Provided with multiple stages of gas collection and release devices arranged in series,
The first-stage gas collection / release device accepts the gas to be treated, and the second-stage and subsequent gas collection / release devices accept the gas released by the preceding-stage gas collection / release device,
Each of the multi-stage gas collection and release devices is
A hydrate generator for generating a hydrate by bringing an aqueous solution of a guest compound that generates a hydrate into contact with a gas and cooling it, thereby collecting the gas;
A hydrate melting device that heats and melts the hydrate produced in the hydrate production device, thereby releasing gas.
The hydrate generation device of the second and subsequent stages of the gas collection / release device has a smaller hydrate generation capability than the hydrate generation device of the gas collection / release device of the previous stage. .

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