JPH0699014A - Pressure swing adsorber with internal heat capacity increased by accumulating material - Google Patents

Abstract

PURPOSE:To effectively prevent the lowering of operating efficiency of equipment with the decrease in effective adsorptive area of an adsorbent due to a change in temperature of the packed bed in a pressure swing adsorber. CONSTITUTION:Accumulating material 3 packed beds whose heat capacity per unit volume is larger than that of an adsorbent are uniformly inserted and arranged between adsorbent packed beds 2 in such a form that the passage of a gaseous starting material through the adsorbent packed beds 2 is not checked. In a CO2 pressure swing adsorption process, from a pressure rise process to the end of a washing process, the temperature in the packed beds 2 rises by over 30 deg.C. This temperature rise causes the lowering of adsorptive performance. Materials of large heat capacity are uniformly inserted and arranged in the packed beds 2 to increase the heat capacity of the whole adsorbent packed beds 2, causing a swing change in temperature of the packed beds 2 during operation due to adsorption and desorption to be sharply relaxed, allowing the effective adsorptive width of the packed adsorbent to be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
_{The present} invention relates to a pressure swing adsorption device for adsorbing and recovering a specific component such as _{2 on} an adsorbent, and particularly to a means for increasing its heat capacity.

[0002]

2. Description of the Related Art Conventionally, for example, as a method of recovering CO ₂ from a raw material gas, an absorption / emission process using an absorbing liquid such as amine has been mainly used. In recent years, however, an adsorbent has been used as an alternative method. A pressure swing adsorption device that switches a plurality of built-in adsorption towers in a short time has come to be adopted.

Further, as means for increasing the adsorption efficiency of such a pressure swing adsorption device, for example, Japanese Patent Laid-Open No. 63-775.
From the idea of reducing the gaps (dead spaces) between adsorbent particles that have no effect on the adsorbing action, Japanese Patent Laid-Open No. 15-151 discloses that the filling gap of the adsorbent filling layer has a smaller particle size and a larger heat capacity than the adsorbent particles. , Loading small particles of activated alumina, polyethylene, rubber, ebonite, porcelain.

[0004]

However, the filling voids of the adsorbent-filled layer described in the above-mentioned publication are filled with small particles having a particle size smaller than that of an adsorbent having a heat capacity of activated alumina, polyethylene, rubber, ebonite, or porcelain. In the conventional method of filling, the pressure loss during operation is high, and as the operation continues, small particles as a heat storage material move below the packed bed, so that in the height direction of the packed bed, the packed bed is filled. Only the lower part of the heat storage effect can be obtained, the effective adsorption area of the adsorbent is reduced by the temperature change of the packed bed, and the scale of the pressure swing adsorption device for obtaining the same product amount is large and uneconomical. I have no choice. In addition, there is a problem that it is difficult to uniformly charge the heat storage material into the gaps between the adsorbent particles.

[0005]

In the pressure swing adsorption apparatus, it has been conventionally common to generally evaluate the function only by the pressure swing in the adsorption tower. However, the present invention is actually the adsorbent in the packed bed. It was completed from the viewpoint that the influence of the temperature swing generated by the adsorption and desorption of gas to and from the gas cannot be ignored.

That is, the present invention is a packed bed for a pressure swing adsorption device, wherein a plurality of perforated plates made of a heat storage material having a heat capacity per unit volume larger than that of an adsorbent are detachably arranged inside the packed bed. Then, an adsorbent was filled between the perforated plates to increase the internal heat capacity by a heat storage material. Furthermore, in the packed bed for a pressure swing adsorption device, the heat capacity per unit volume is adsorbed inside the packed bed. Characterized by arranging a heat storage material having a regular shape having a size larger than the adsorbent and larger than the particle size of the adsorbent, filling the adsorbent between the heat storage materials, and increasing the internal heat capacity by the heat storage material And

[0007]

For example, in the CO ₂ pressure swing adsorption process, the temperature in the packed bed rises by about 30 ° C. from the pressurization step to the end of the cleaning step. This increase in temperature causes a decrease in adsorption performance. By uniformly loading and arranging the material with large heat capacity in the packed bed, the heat capacity of the whole adsorbent packed bed is increased, and the swing fluctuation of the packed bed temperature during operation due to adsorption / desorption is significantly reduced. , Increase the effective adsorption width of the filled adsorbent.

An iron material such as SUS or carbon steel is suitable as an example of the heat storage material having a larger heat capacity than the adsorbent.

Further, the above-mentioned problems, that is, uniform charging of the heat storage material into the gaps between the adsorbent particles, prevention of movement of the heat storage material below the packed bed due to operation, and further pressure loss due to passage of gas in the packed bed In order to lower the temperature, the shape of the heat storage material and the method of installing the heat storage material on the packed bed may be as follows.

For example, a plurality of perforated plates having holes smaller than the particle size of the adsorbent are arranged in the packed bed in the height direction, and the adsorbent is inserted between the perforated plates.

As another method, it is convenient to form a square bar, a round bar, or a tetra-pot shape so that the gas passage is not hindered even if the iron plate is arbitrarily filled and arranged.

Particularly, in the heat storage material formed in a tetrapot shape or the like, as shown in FIGS. 3 (a) and 3 (b), the adsorbent and the heat storage material can be easily evenly inserted into the packed bed, and the pressure loss also occurs. It is particularly preferable because it is low, and further, the heat storage material does not move below the packed bed due to the operation.

[0013]

EXAMPLE In a cylindrical adsorption tower 1 having a diameter of 1000 mm and a height of 1200 mm shown in FIG. 1, a heat storage material 3 made of a porous plate made of SUS in a packed bed 2 made of an adsorbent having an average particle diameter of 3 to 5 mm. With a thickness of 10 mm and an aperture ratio of 50% at 100 mm pitch
Forming a heat storage material layer of C, and about 40 ° C. from the gas inlet 4
CO that introduces an O ₂ -containing gas and discharges it from the gas discharge port 5
_Two adsorption operations were performed. This SUS has about 13 times the heat capacity per unit volume of the adsorbent.

FIG. 2 is a diagram showing changes in the effective adsorption amount of the adsorbent due to charging of the heat storage material.

FIG. 3A shows the adsorbent isotherm curve
The effective CO ₂ adsorption amount when the heat storage material is inserted is shown, and the same figure (b) shows the effective CO ₂ adsorption amount when the heat storage material is not charged.

In FIG. 1B, if there is no heat or heat absorption during adsorption / desorption and no temperature swing occurs, PS
The operation A is performed as a → b and b → a in the figure (for example, isothermal at 10 ° C.), and a large effective adsorption amount (27.6 ml / g) is obtained, but the temperature swing is actually caused by adsorption / desorption heat. (10 → 44.3 ° C., 44.3 → 10 ° C.) occurs, and the effective adsorption amount decreases (10.4 ml /
g). The temperature swing is reduced by charging the heat storage material as shown in FIG.
0.3 ° C., 40.3 → 10 ° C., and the effective adsorption amount increases more than in the case of FIG. 7B (13.8 ml /
g). As is clear from the comparison between the figures (a) and (b), the figure (a) in which the heat storage material according to the present invention is charged improves the effective CO ₂ adsorption amount (about 30%). ) Can be seen.

Incidentally, in the embodiment, from the source gas to C
Although the adsorption / recovery of O ₂ has been described, the present invention is not limited to this, and can be widely and effectively utilized in a field such as CO / PSA having the same problem as CO ₂ / PSA. is there.

[0018]

According to the present invention, the adsorbent and the heat storage material can be evenly inserted into the filling material layer, and the heat storage material is not moved to the lower side of the filling material layer due to the operation, so that the heat capacity of the filling material layer is filled. It is possible to raise the temperature uniformly throughout the bed, and it is also possible to raise the heat capacity in a stable manner during operation, which greatly improves the adsorption performance.

[Brief description of drawings]

FIG. 1 shows a configuration diagram of an adsorption tower to which the present invention is applied.

FIG. 2 is a diagram showing changes in the effective adsorption amount of an adsorbent due to charging of a heat storage material. The figure (a) shows the change when a heat storage material is charged, and the figure (b) shows the change when there is no heat storage material.

FIG. 3 is a diagram showing an example in which a tetrapod-shaped heat storage material is used.

[Explanation of symbols]

 1 Adsorption Tower 2 Packed Bed 3 Heat Storage Material 4 Gas Inlet 5 Gas Outlet

Claims (2)

[Claims] 1. A packed bed for a pressure swing adsorption device, wherein a plurality of perforated plates made of a heat storage material having a heat capacity per unit volume larger than that of an adsorbent are detachably arranged inside the packed bed, A packed bed for a pressure swing adsorption device having an internal heat capacity increased by a heat storage material, characterized in that an adsorbent is filled between the plates. 2. A packed bed for a pressure swing adsorption apparatus, wherein a heat storage material having a regular shape having a heat capacity per unit volume larger than that of the adsorbent and larger than the particle size of the adsorbent is provided inside the packed bed. A packed bed for a pressure swing adsorption device in which an internal heat capacity is increased by a heat storage material, which is disposed and filled with an adsorbent between the heat storage materials.