JP3134525U - Gas separator - Google Patents

Abstract

A gas separation apparatus in which an inorganic porous hollow fiber membrane module is housed in a hermetically sealed container as a gas separation membrane, which does not cause damage to the gas separation membrane even at the time of gas separation processing performed at a high temperature. provide.
A module made of an inorganic porous hollow fiber membrane, preferably a porous ceramic hollow fiber membrane, is formed, with one end of the hollow fiber membrane serving as the gas inlet and the other end of the hollow fiber membrane. In the gas separation apparatus configured to receive the separated gas from the recovery port of the sealed container, the inorganic porous hollow fiber membrane is made to be a spring coil. A gas separation device configured in a shape and housed in an airtight container.
[Selection] Figure 4

Description

  The present invention relates to a gas separation device. More specifically, the present invention relates to a gas separation apparatus using a gas separation membrane.

  The gas separation method using various gas separation membranes has characteristics such as energy saving without phase change at the time of separation, unlike the evaporation method and the cryogenic separation method, and this method is applied. The gas separation device has a configuration in which a gas separation membrane is accommodated in a sealed container including a gas to be treated inlet, a separation residual gas discharge port, and a separation gas recovery port.

  Various materials can be applied as the material for the sealed container, but generally a metal such as stainless steel is often used. On the other hand, as the gas separation membrane, a dense metal tube, a polymer membrane, an inorganic porous membrane carrying a functional layer, or the like is used.

  Among them, the gas separation membrane in which the functional layer is supported on the inorganic porous membrane can reduce the thickness of the functional layer to be supported, so that the permeation speed and heat resistance can be increased, and the separation performance can be arbitrarily designed. And so on. However, if a gas separation device in which both ends of the gas separation membrane of the straight pipe are fixed to a closed vessel is used at a high temperature, the gas separation membrane may be damaged due to a stress caused by a difference in thermal expansion coefficient between the gas separation membrane and the closed vessel. There is.

A gas separation membrane that only supports one end side of the gas separation membrane and is supported in a suspended manner has been proposed. In this case, the end surface of the gas separation membrane on the non-fixed side is covered with an inorganic adhesive, brazing material, etc. Not only makes the process complicated, but also causes problems such as lack of reliability because the sealing portion is exposed to high temperatures. In particular, when the hollow fiber membrane diameter is reduced and the number of hollow fiber membranes used per module is increased, the workability is poor due to the high viscosity of the inorganic adhesive, and the adhesive is further cured when the adhesive is thermally cured. There is a problem of cracking in the layer.
JP-A-6-191802 Japanese Patent Laid-Open No. 2003-144861

  Also, in the modularization of porous ceramic hollow fiber membranes, if there is a difference in the thermal expansion coefficient between the hollow fiber membrane, adhesive, and module case, the porous ceramic hollow fiber membrane is Stress may be applied to the yarn membrane, and the hollow fiber membrane may be damaged.

  Furthermore, when only the module case is made of ceramics and has a small thermal expansion coefficient, the case may not be able to withstand the thermal expansion of the adhesive and the case may be broken. Therefore, in the modularization of small-diameter porous hollow fiber membranes, the case, porous hollow fiber membrane, and adhesive members have the same thermal expansion coefficient, or the stress generated by the difference in thermal expansion coefficient is buffered. It is essential to do.

The present applicant has previously described a gas separation apparatus in which an inorganic porous hollow fiber membrane module is housed in a sealed container as a gas separation membrane, and the gas separation membrane is damaged even at the time of gas separation processing performed at a high temperature. A module composed of a U-shaped inorganic porous hollow fiber membrane having a functional layer supported on the membrane surface is formed as one that is not squeezed, and one end of the hollow fiber membrane is used as a gas inlet for treatment and the other hollow fiber is provided. A gas separation device has been proposed in which the end of the membrane is accommodated in a sealed container so as to be connected to the separation residual gas discharge port, and the separated gas is taken out from the recovery port of the sealed container.
JP 2001-212422 A

  However, in this proposed configuration, the single-support type structure has a structure in which thermal stress is not applied to the porous ceramic hollow fiber membrane, but there is a gas inlet and outlet on one side. , The connection is difficult and the seal structure is complicated.

  The object of the present invention is a gas separation apparatus in which an inorganic porous hollow fiber membrane module is housed in a sealed container as a gas separation membrane, and causes damage to the gas separation membrane even at the time of gas separation processing performed at a high temperature. To provide something not.

  An object of the present invention is to form a module composed of an inorganic porous hollow fiber membrane, one end of the hollow fiber membrane being used as a gas inlet, and the other end of the hollow fiber membrane being a separation residual gas outlet. In the gas separation device configured to be housed in a sealed container so as to be connected to each other and to take out the separated gas from the recovery port of the sealed container, the inorganic porous hollow fiber membrane is configured in a spring coil shape and the sealed container This is achieved by a gas separation device housed inside.

  The gas separation membrane device according to the present invention is housed in a sealed container serving as a module case with a hollow fiber membrane formed in a spring coil shape even in a module using a hollow ceramic hollow fiber membrane having a small diameter. Therefore, even when it is used for gas separation treatment at high temperature, the stress due to the difference in thermal expansion coefficient between the container and the hollow fiber membrane is relieved, and the hollow fiber membrane is effectively prevented from being damaged by thermal shock. can do. In addition, the module case material and the adhesive can be selected according to the application.

  A spring coil-shaped inorganic porous hollow fiber membrane, preferably a porous ceramic hollow fiber membrane, is manufactured by a method as shown in FIGS. Porous ceramic hollow fiber membranes are obtained by dry-wet spinning of a spinning stock solution (dope solution) filled with ceramic powder in an organic solvent solution of a polymer material, followed by firing, and dry-wet spinning. As shown in FIG. 1, the hollow fiber membrane 11 formed in this way is attached to a rod-like support jig 14 having narrow diameter portions 12 and 12 'at both ends and a large diameter portion 13 at the center, and a spring coil. The shape is wound and dried at room temperature for about a day and night, and the shape is temporarily fixed. As shown in the front view (a) and plan view (b) of FIG. 2, the temporarily fixed spring coil-shaped hollow fiber membrane 15 is placed on a firing table 16 having a shape that matches the spring coil shape, and is heated to a predetermined temperature. By firing with a porous ceramic hollow fiber membrane is formed.

  A perspective view of the gas separation apparatus using the inorganic porous hollow fiber membrane 1 having the spring coil shape thus produced is shown in FIG. 3, and a longitudinal sectional view of the center line is shown in FIG. The spring-shaped inorganic porous hollow fiber membrane 1 has a gap between both end portions thereof sealed by the adhesive layers 2 and 2 ′ and is accommodated in a sealed container 10 that becomes a module case to form a module 3. The one and the other hollow fiber membrane end portions that are modularized are connected to the gas inlet 4 and the separation residual gas outlet 5 provided at the upper and lower portions of the module case 10, respectively. Covered with heads 7, 7 '. The lower head 7 'is provided with a separated gas recovery port 6. The upper head 7 and the lower head 7 ′ are connected to each other by bolting with bolts 9, and fix the module 3. Further, each gas flow path is hermetically sealed by O-rings 8 and 8 '.

As a porous ceramic hollow fiber membrane, generally used is an organic solvent solution of a polymer material in which powders of Al ₂ O ₃ , Y ₂ O ₃ , MgO, SiO ₂ , Si ₃ N ₄ , ZrO _{2 and the} like are dispersed, The pore diameter obtained by dry and wet spinning is about 0.1 to 6 μm, preferably about 0.2 to 2 mm, the outer diameter is about 0.5 to 4 mm, preferably about 1 to 3 mm, and the film thickness is about 0.1 to 0.5 mm, preferably Is about 0.15 to 0.3 mm. A functional layer can be supported on the surface of the membrane. For example, a material supporting Pd, Pd alloy or silica is used as a hydrogen gas separation membrane, and a material supporting zeolite is used as a carbon dioxide separation membrane.

  As the module case which is a sealed container, those made of inorganic ceramics such as alumina, zirconia and titania are also used, but from the viewpoint of processability and price, a case made of hard resin such as acrylic resin or polysulfone resin or quartz glass, etc. The glass case is used. Spring coil-shaped inorganic porous hollow fiber membranes generally have a thickness of about 15 to 25 mm due to the adhesive 2 having a low viscosity, such as epoxy resin and urethane resin, and excellent heat resistance and durability. The module 3 is formed by sealing.

  For gas separation, for example, in the case of a hydrogen gas separation device using a ceramic porous hollow fiber membrane in which Pd metal is supported on the membrane surface, the gas to be treated is fed from the gas inlet to the inner tube of each porous hollow fiber membrane. The hydrogen gas contained in the gas to be treated is selectively permeated through the hydrogen gas separation hollow fiber membrane and collected in a sealed container, collected from the gas recovery port, and residual hydrogen from the gas to be treated. Separation residual gas consisting of gas other than gas and hydrogen gas is discharged from the gas outlet.

  During the hydrogen gas separation process, the sealed container and the hydrogen gas separation hollow fiber membrane are heated to a high temperature of about 300-500 ° C. However, since the hydrogen gas separation hollow fiber membrane has a spring coil shape, the vessel and the hydrogen gas separation are separated. The stress due to the difference in thermal expansion coefficient with the hollow fiber membrane is relieved, and this prevents the hydrogen gas separation hollow fiber membrane from being damaged during the high temperature treatment.

  Next, this invention is demonstrated about an Example.

Example: A polysulfone resin case with an inner diameter of 25 mm, an outer diameter of 30 mm, and a length of 180 mm contains a spring-coiled porous alumina hollow fiber membrane with an inner diameter of 2.2 mm and an outer diameter of 3.0 mm. Epoxy resin was poured so as to be about 20 mm, and both ends of the spring coil-shaped hollow fiber membrane were fixed. About the produced module,
1 hour at -20 ℃
Temperature rise from -20 ℃ to 100 ℃ over 2 minutes
1 hour at 100 ℃
Ten cycles of thermal shock tests were performed in which the temperature was lowered to 1 cycle over 2 minutes from 100 ° C. to −20 ° C., but no crack was observed in the porous alumina hollow fiber membrane.

Comparative Example In the example, instead of the spring coil-shaped hollow fiber membrane, both ends of the linear hollow fiber membrane were fixed, and a similar thermal shock test was performed on the manufactured module. Cracks were found in the porous alumina hollow fiber membrane.

It is a perspective view which shows the state in which the dry-wet spinning hollow fiber membrane of the spring coil shape was formed. FIG. 2 is a front view (a) and a plan view (b) showing a state in which a spring coil-shaped dry and wet spun hollow fiber membrane is fired. It is a perspective view which shows the state which accommodated the spring coil-shaped inorganic type porous hollow fiber in the module case. It is a center line sectional view of one mode of a gas separation device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inorganic porous hollow fiber membrane 2 Adhesive 3 Module 4 Processed gas introduction port 5 Separation residual gas discharge port 6 Separation gas collection port 7 Head 8 O-ring 9 Bolt 10 Airtight container (module case)

Claims (3)

  A module comprising an inorganic porous hollow fiber membrane is formed and sealed so that one end of the hollow fiber membrane is connected to the treated gas inlet and the other end of the hollow fiber membrane is connected to the separation residual gas outlet. In a gas separation apparatus configured to take out separated gas from a recovery port of a sealed container, and accommodated in the container, an inorganic porous hollow fiber membrane is formed in a spring coil shape and stored in the sealed container .   The gas separation membrane device according to claim 1, wherein the inorganic porous hollow fiber membrane is a porous ceramic hollow fiber membrane.   The gas separator according to claim 1 or 2, wherein a spring coil-shaped inorganic porous hollow fiber membrane having a functional layer supported on the membrane surface is used.

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