JP2022048987A - Adsorption tower, temperature measurement method of adsorbent, separation drive force calculation method of target gas, degradation state determination method of adsorbent and operation method of pressure swing adsorption equipment - Google Patents

Abstract

To provide an adsorption tower, a temperature measurement method of an adsorbent, a separation drive force calculation method of a target gas, a degradation state determination method of the adsorbent and an operation method of pressure swing adsorption equipment where the temperature of the adsorbent can be accurately measured suppressing pressure loss and at a low cost when separating the target gas from a raw material gas by a pressure swing adsorption method.SOLUTION: An adsorption tower 1 in pressure swing adsorption equipment comprises: an adsorption tower body 11 filled with an adsorbent adsorbing a target gas component; a thermocouple insertion pipe 12 set over the total length of the adsorption tower body 11 in parallel to the flow direction of a gas in the adsorption tower body 11; a thermocouple 13 being inserted into the thermocouple insertion pipe 12 and measuring the temperature of the adsorbent A in the adsorption tower body 11; and a thermocouple position movement control means 14 where the position of the thermocouple 13 in the thermocouple insertion pipe 12 is moved and the thermocouple 13 can measure the temperature of the adsorbent A at an arbitrary position in the thermocouple insertion pipe 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adsorption tower, a method for measuring the temperature of an adsorbent, a method for calculating the separation power of a target gas, a method for determining a deterioration state of an adsorbent, and a method for operating a pressure swing adsorption facility.

Conventionally, a pressure swing adsorption (PSA) method is known as a method for separating and recovering a target gas component contained in a raw material gas. The PSA method is a gas separation method that utilizes the difference in the amount of gas component adsorbed on the adsorbent, the gas type, and the partial pressure. It consists of a cleaning step of increasing the adsorption rate of the component and a desorption step of desorbing the target gas component from the adsorbent to separate and recover the high-concentration target gas.

Normally, the power consumption required for the separation and recovery of the target gas in the PSA of the actual machine scale is calculated from the power consumption of the vacuum pump, the booster, and the like. On the other hand, in the lab scale PSA, since the suction pressure of the vacuum pump is adjusted by the change of the suction flow rate according to the opening degree of the needle valve, a direct correlation with the output of the vacuum pump cannot be obtained.

In the adsorption process, heat of adsorption is generated when the gas component is adsorbed to the adsorbent, and in the desorption process, heat of adsorption is generated according to the amount of desorbed gas when suction and desorption with a vacuum pump, and the temperature of the adsorbent rises. A changing phenomenon is known (see, for example, Non-Patent Document 1). Since the power of the vacuum pump is considered to be proportional to the generated heat of adsorption, it is considered that the separation power of the target gas can be approximately calculated from the heat of adsorption obtained from the temperature change (ΔT) of the adsorbent per cycle of PSA. ..

The absolute value of the temperature change ΔT increases as the amount of gas adsorbed on the adsorbent increases, and the amount of gas adsorbed decreases from the raw material gas supply port side to the discharge port side of the adsorption tower. It shows a tendency to gradually decrease from the raw material gas supply port side to the discharge port side of the adsorption tower.

As a method for measuring the temperature change ΔT, there is a method of inserting a thermocouple inside the adsorption tower filled with the adsorbent and measuring the temperature change ΔT of the adsorbent according to the height position in the adsorption tower. Further, by measuring the temperature change ΔT at the height position in the adsorption tower, it is possible to indirectly measure to what height position the target gas component is adsorbed with respect to the filling region of the adsorbent. It is possible to prevent the target gas from breaking out.

For example, in Patent Document 1 and Patent Document 2, in the PSA method, the operating conditions are automatically controlled based on the values measured by the thermocouple in the temperature change of the adsorption tower during the adsorption operation to prevent the target gas from breaking. Such a method of temperature measurement has been proposed.

Further, by measuring the temperature change at a predetermined height position in the adsorption tower, the deterioration state of the adsorbent over time can be indirectly measured. For example, Patent Document 3 proposes a method of determining the life and deterioration of an adsorbent by measuring a temperature change of the adsorbent with a thermocouple provided in the adsorption tower in the PSA method.

Japanese Unexamined Patent Publication No. 5-155603 Japanese Unexamined Patent Publication No. 2014-73461 Japanese Unexamined Patent Publication No. 8-117541

Masaomi Tomomura, Shunsuke Nokita, Journal of Chemical Engineering, 1987, Vol. 13, No. 2, p. 139-144

So far, in the PSA method, a method for separating and recovering the target gas at a concentration and recovery rate higher than desired has been investigated by adjusting the adsorption step and the desorption step based on the measured values of the temperature change of the adsorbent filled in the adsorption tower. It has been. However, in the method described in Patent Document 1, since the type of adsorbent is a method for separating and recovering chlorine gas limited to zeolite, non-zeolite-based porous acidic oxide, activated carbon or molecular sieve carbon, chlorine to be separated and recovered. There is a problem that ΔT cannot be measured accurately unless the difference in ΔT from the subcomponent gas is sufficiently large with respect to the gas.

Further, in the methods described in Patent Document 2 and Patent Document 3, it is necessary to match the number of tubes into which thermocouples for measuring the temperature change of the adsorbent are inserted with the number of thermocouples, which increases the equipment cost. There's a problem. Further, since the thermocouple is inserted perpendicular to the gas flow direction, there is a problem such as pressure loss due to the obstruction of the gas flow.

The present invention has been made in view of the above problems, and an object thereof is to lower the temperature of the adsorbent by suppressing pressure loss when separating the target gas from the raw material gas by the pressure swing adsorption method. It is an object of the present invention to provide an adsorption tower that can be accurately measured at cost, a method for measuring the temperature of an adsorbent, a method for calculating the separation power of a target gas, a method for determining a deterioration status of an adsorbent, and a method for operating a pressure swing adsorption facility.

The present invention that solves the above problems is as follows.

[1] A suction tower of a pressure swing suction facility.
The main body of the adsorption tower filled with an adsorbent that adsorbs the target gas component,
A thermocouple insertion tube installed over the entire length of the adsorption tower body parallel to the gas flow direction in the adsorption tower body.
A thermocouple inserted into the thermocouple insertion tube and measuring the temperature of the adsorbent in the main body of the adsorption tower.
Thermocouple position movement control means that moves the position of the thermocouple in the thermocouple insertion tube to allow the thermocouple to measure the temperature of the adsorbent at any position in the thermocouple insertion tube. When,
A suction tower characterized by having.

[2] The method for measuring the temperature of the adsorbent in the adsorbent according to the above [1].
The first temperature measurement step of measuring the temperature of the adsorbent in one cycle of the pressure swing at at least three measurement points along the gas flow direction in the adsorption tower main body.
A first adsorbent temperature change calculation step for calculating the temperature change ΔT of the adsorbent in one cycle of the pressure swing with respect to the temperature of the adsorbent measured in the first temperature measurement step.
A method for measuring the temperature of an adsorbent, which comprises.

[3] Of the temperature change ΔT obtained for each measurement point in the first adsorbent temperature change calculation step, the minimum adsorption for determining the minimum adsorbent temperature change point in which the temperature change ΔT having the smallest value is measured. The agent temperature change point determination step and
A plurality of measurement points are provided at equal intervals between the minimum adsorbent temperature change point determined in the minimum adsorbent temperature change point determination step and the measurement point on the most raw material gas supply port side in the adsorption tower main body. A second temperature measurement step of measuring the temperature of the adsorbent at each measurement point,
With respect to the temperature of the adsorbent measured in the second temperature measurement step, the second adsorbent temperature change calculation step for calculating the temperature change ΔT of the adsorbent in one cycle of the pressure swing, and the second adsorbent temperature change calculation step.
The method for measuring the temperature of the adsorbent according to the above [2].

[4] A method of calculating the separation power of the target gas in the pressure swing adsorption method.
Specific heat _Cpads (J / kg · K) of the adsorbent, mass _Mads (kg) of the adsorbent, adsorption amount M _gas (kg) of the target gas, and in the adsorption tower according to the above [2] or [3]. Using the adsorbent temperature change ΔT (K) measured by the adsorbent temperature measuring method and the power conversion coefficient C, the separation power W _gas (Wh / kg-gas) of the target gas is calculated by the following formula (A). A method for calculating the separation power of a target gas, which is characterized by using. Here, the electric power conversion coefficient C is a coefficient for converting energy (J) into electric energy (Wh).

[5] A method for determining the deterioration status of the adsorbent in the pressure swing adsorption equipment.
The time change of the temperature change ΔT of the adsorbent at the measurement point in the adsorption tower main body was obtained by the method for measuring the temperature of the adsorbent in the adsorption tower according to the above [2] or [3].
Determining the deterioration status of the adsorbent, which is characterized in that it is determined that the adsorbent in the region where the temperature change ΔT has decreased from the start of gas separation is deteriorated at the stage when the predetermined target gas recovery rate cannot be achieved. Method.

[6] This is a method of operating the pressure swing suction equipment.
A deterioration adsorbent specifying step for specifying a region filled with the adsorbent deteriorated by the method for determining the deterioration status of the adsorbent according to the above [5], and a step for specifying the deteriorated adsorbent.
An adsorbent exchange step of exchanging only the adsorbent filled in the identified region, and an adsorbent exchange step.
A method of operating a pressure swing adsorption facility, characterized in that it has.

According to the present invention, when the target gas is separated from the raw material gas by the pressure swing adsorption method, the temperature of the adsorbent can be accurately measured at low cost by suppressing pressure loss.

It is a figure which shows an example of the suction tower of the pressure swing suction equipment by this invention. It is a figure which shows an example of the pressure swing suction equipment to which the suction tower by this invention is applicable. It is a schematic diagram of the relationship between the height position in the adsorption tower (the main body of the adsorption tower) and the temperature change in one cycle of the pressure swing of the adsorbent. It is a figure which shows the temperature change of the adsorbent in one cycle of a pressure swing in the case of a cycle time of 100 seconds, (a) is for the case of 5 measurement points, (b) is for the case of 20 measurement points. It is a figure which shows the temperature change of the adsorbent in one cycle of a pressure swing in the case of a cycle time of 300 seconds, (a) is for the case of 5 measurement points, (b) is for the case of 20 measurement points.

(Suction tower of pressure swing suction equipment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a suction tower of a pressure swing suction facility according to the present invention. The suction tower 1 shown in FIG. 1 includes a suction tower main body 11, a thermocouple insertion tube 12, a thermocouple 13, and a thermocouple position movement control means 14.

The adsorption tower main body 11 is a tubular member constituting the main body of the adsorption tower 1, and beads B and sponge S1 are sequentially arranged from the bottom inside the adsorption tower main body 11, and an adsorbent A that adsorbs a target gas component on the beads B and a sponge S1. Is filled. The adsorbent A is sequentially filled with the sponge S1, the beads B, and the sponge S2 having a coarser mesh than the sponge S1. The beads B are provided so that the raw material gas from the raw material gas supply pipe (not shown) connected to the lower part of the adsorption tower main body 11 is uniformly dispersed in the adsorption tower main body 11. As the raw material gas, a by-product gas from a steel mill can be used, and for example, a blast furnace gas can be preferably used.

The thermocouple insertion tube 12 is parallel to the flow direction of the gas (raw material gas) in the adsorption tower main body 11 (that is, along the side wall surface of the adsorption tower main body 11 (the length direction of the adsorption tower main body 11)). It is installed over the entire length of the suction tower main body 11, and is configured so that the thermocouple 13 can be inserted inside. The thermocouple insertion tube 12 is not particularly limited as long as it is made of a material having sufficient resistance to heat generated during the operation of the PSA facility, but the adsorbent A at an arbitrary position in the adsorption tower main body 11 is used. It is preferably made of a material such as a metal having high thermal conductivity so that heat can be transferred to the thermocouple 13 well.

The thermocouple 13 is inserted inside the thermocouple insertion tube 12, and is configured to be movable in the thermocouple insertion tube 12 along the length direction of the suction tower main body 11 by the thermocouple position movement control means 14. , The temperature of the adsorbent A can be measured at an arbitrary position in the adsorption tower main body 11 in the length direction. As the thermocouple 13, a known appropriate one can be used.

In the present invention, the temperature of the adsorbent A at a predetermined position in the adsorption tower main body 11 means the temperature measured by arranging the thermocouple 13 at the predetermined position.

The thermocouple position movement control means 14 is configured so that the thermocouple 13 can be moved inside the thermocouple insertion tube 12.

FIG. 2 shows an example of a PSA adsorption facility to which the adsorption tower according to the present invention can be applied. The two-tower type PSA facility shown in FIG. 2 is equipped with an adsorption tower 1 equipped with a raw material gas supply port and a raw material gas discharge port, and in parallel with being sucked and depressurized by a vacuum pump, it can be used as an impurity gas and a recovered gas. Separated and collected. The raw material gas is introduced into the adsorption tower 1 from the raw material gas supply port, and is pressurized to a predetermined pressure in the adsorption tower 1, so that the target gas component is selectively adsorbed on the adsorbent A.

In order to separate and recover the target gas component adsorbed on the adsorbent A, the inside of the adsorption tower 1 can be depressurized by a vacuum pump to separate and recover the high-purity target gas component. Since the gas components other than the target gas component are difficult to be adsorbed by the adsorbent A, they are recovered from the initial stage of suction in the desorption step. Since the target gas component is desorbed with a delay, the target gas with high purity can be recovered with a time lag.

As described above, in the adsorption tower 1 according to the present invention, the thermocouple insertion tube 12 is installed parallel to the gas flow direction in the adsorption tower main body 11 over the entire length of the adsorption tower main body 11, and the thermocouple 13 is installed. It is configured to be movable to an arbitrary position in the suction tower main body 11 in the thermocouple insertion tube 12. As a result, the measurement point of the temperature of the adsorbent A by the thermocouple 13 can be arbitrarily determined, the measurement point is not limited, and the temperature change ΔT of the adsorbent A at a predetermined position can be measured. can. As a result, the adsorbent-filled region filled in the adsorption tower main body 11 can be subdivided to enable more accurate measurement of ΔT.

At the same time, since accurate ΔT can be measured even when there is no large difference in the degree of adsorption of each gas type constituting the raw material gas, the operating conditions are set in the PSA method for maintaining the recovery rate of the target gas. It becomes possible to set.

Further, as compared with the case where the thermocouple is introduced in the gas flow direction as in Patent Documents 2 and 3, it is possible to suppress the obstruction of the gas flow and reduce the pressure loss. The effect on the gas concentration and recovery rate can be reduced.

(Method of measuring the temperature of the adsorbent in the adsorption tower)
Next, a method for measuring the temperature of the adsorbent in the adsorption tower according to the present invention will be described. The method for measuring the temperature of the adsorbent in the adsorption tower according to the present invention is the method for measuring the temperature of the adsorbent A in one cycle of the pressure swing at at least three measurement points along the gas flow direction in the adsorption tower 1 according to the present invention described above. For the first temperature measurement step for measuring the temperature and the temperature of the adsorbent A measured in the first temperature measurement step, the temperature change ΔT of the adsorbent A in one cycle of the pressure swing is calculated. It is characterized by having a calculation step.

As described above, in the adsorption tower of the PSA facility according to the present invention, the thermocouple insertion tube 12 is installed parallel to the gas flow direction in the adsorption tower main body 11 over the entire length of the adsorption tower main body 11. The pair 13 is configured to be movable at an arbitrary position in the suction tower main body 11 in the thermocouple insertion tube 12. Therefore, first, the temperature of the adsorbent A in one cycle of the pressure swing is measured at at least three or more measurement points along the gas flow direction in the adsorption tower main body 11 (first temperature measurement step).

It is preferable that the three or more measurement points are the points closest to the raw material gas supply port, the points closest to the recovery gas discharge port, and the points in between. Further, as shown in Examples described later, it is preferable that the number of measurement points is large because the analysis accuracy using the value of ΔT is improved.

Next, for the adsorbent A temperature measured in the first temperature measurement step, the temperature change ΔT of the adsorbent A in one cycle of the pressure swing is calculated (first adsorbent temperature change calculation step). Based on the ΔT thus obtained, it is possible to calculate the power when separating and recovering the target gas component from the raw material gas, determine the deterioration status of the adsorbent, and the like.

The temperature of the adsorbent may be measured in two steps. Specifically, first, in the first step, the above-mentioned first temperature measurement step and the first adsorbent temperature change calculation step are performed. This makes it possible to grasp the tendency of ΔT in the suction tower 1 (suction tower main body 11). Next, in the second step, among the temperature change ΔT obtained for each measurement point in the first adsorbent temperature change calculation step, the minimum adsorbent temperature change point at which the smallest value is measured is determined. (Minimum adsorbent temperature change point determination step).

Subsequently, between the minimum adsorbent temperature change point determined in the minimum adsorbent temperature change point determination step and the measurement point on the most raw material gas supply port side in the adsorption tower main body, the above-mentioned first temperature measurement step and Repeat the same steps as the adsorbent temperature change calculation step. Specifically, a plurality of first measurement points are provided at equal intervals between the minimum adsorbent temperature change point and the measurement point on the most raw material gas supply port side in the adsorption tower body, and adsorption is performed at each measurement point. The temperature of the agent is measured (second temperature measurement step). Then, with respect to the temperature of the adsorbent A measured in the second temperature measurement step, the temperature change ΔT of the adsorbent A in one cycle of the pressure swing is calculated (second adsorbent temperature change calculation step).

In this way, as compared with the case where the temperature measurement step and the adsorbent temperature change calculation step are performed only once, after grasping the tendency of ΔT in the adsorption tower 1 (adsorption tower main body 11), it is limited to the region where the ΔT fluctuates. Then, the temperature of the adsorbent A can be measured to calculate ΔT in the PSA1 cycle. As a result, it is possible to calculate the separation power of the target gas component using ΔT and determine the deterioration of the adsorbent with higher accuracy.

(Calculation method of separation power of target gas)
Subsequently, a method for calculating the separation power of the target gas according to the present invention will be described. The method for calculating the separation power of the target gas according to the present invention includes the specific heat C _pads (J / kg · K) of the adsorbent, the mass _Mads (kg) of the adsorbent, the adsorption amount M _gas (kg) of the target gas, and the above-mentioned book. Using the temperature change ΔT (K) of the adsorbent measured by the method for measuring the temperature of the adsorbent in the adsorption tower according to the invention and the power conversion coefficient C, the separation power W _gas (Wh / kg-gas) of the target gas is as follows. It is characterized in that it is calculated using the formula (A) of. Here, the electric power conversion coefficient C is a coefficient for converting energy (J) into electric energy (Wh), and has a relationship of 3600 (J) = 1 (Wh).

The sum (sigma) of the right side of the above formula (A) is performed with respect to the number of temperature change ΔT (that is, the number of measurement points of the temperature of the adsorbent A). Further, for the mass _Mads of the adsorbent, a value obtained by dividing the mass of the entire adsorbent A filled in the adsorption tower by the number of measurement points of the temperature of the adsorbent A is input.

In this way, the separation power of the target gas can be calculated with high accuracy based on the value of the temperature change ΔT of the adsorbent A filled in the adsorption tower 1 (adsorption tower main body 11) in the PSA1 cycle.

(Method of determining the deterioration status of the adsorbent)
Subsequently, a method for determining the deterioration state of the adsorbent according to the present invention will be described. The method for determining the deterioration status of the adsorbent according to the present invention is a method for determining the deterioration status of the adsorbent in the pressure swing adsorption facility, and the adsorption tower main body is determined by the above-mentioned method for measuring the temperature of the adsorbent in the adsorption tower according to the present invention. The time change of the temperature change ΔT of the adsorbent A at the measurement point in 11 is obtained, and when the predetermined target gas recovery rate cannot be achieved, the adsorbent A in the region where the temperature change ΔT has decreased from the start of gas separation. Is characterized in that it is determined that the gas has deteriorated.

In carrying out the PSA operation, the adsorption performance of the adsorbent A deteriorates due to clogging of the pores in the adsorbent A, reduction of crystal pores due to a chemical reaction, or the like. FIG. 3 shows a schematic diagram of the relationship between the height position h in the adsorption tower 1 (adsorption tower main body 11) and the temperature change ΔT of the adsorbent A in the PSA1 cycle. At the height position h in the adsorption tower 1 (adsorption tower main body 11), among the measurement points of the temperature change ΔT of the adsorbent A, the point A is the measurement point closest to the raw material gas supply side, and the point B is on the discharge port side. The closest measurement point. FIG. 3 shows how the adsorption performance of the adsorbent A deteriorates in the order of the states a → b → c.

Since the adsorbent A has a high degree of adsorbing the target gas component in the region near the raw material gas supply port side, the degree of deterioration is also high. On the other hand, in the region near the raw material gas discharge port side, the degree of adsorption of the target gas component is low, so the degree of deterioration is also low.

As the adsorbent A deteriorates, the amount of the target gas component adsorbed decreases, so that the temperature change ΔT at point A on the raw material gas supply port side decreases in the order of I → II → III. On the other hand, at point B, since the target gas component that has passed through without being adsorbed from the raw material gas supply port side is adsorbed by the adsorbent A, it tends to increase in the order of I'→ II'→ III'.

Here, assuming that the condition that the target gas component does not break is the state a, if the temperature change rise is confirmed from ΔT _min at the point B, it means that the target gas component has broken. Can be done. However, even if the target gas component is broken, there is no problem as long as the predetermined target gas recovery rate can be achieved.

Therefore, in the present invention, the time change of the temperature change ΔT of the adsorbent A at the measurement point in the adsorption tower main body 11 is obtained by the above-mentioned method for measuring the temperature of the adsorbent in the adsorption tower according to the present invention, and the predetermined target gas is obtained. When the recovery rate cannot be achieved, it is determined that the adsorbent A in the region where the temperature change ΔT has decreased from the start of gas separation has deteriorated.

The stage at which the predetermined target gas recovery rate cannot be achieved can be determined, for example, based on the total value of the temperature changes ΔT at all the measurement points.

(Operation method of pressure swing adsorption equipment)
Next, the operation method of the pressure swing suction equipment according to the present invention will be described. The operation method of the pressure swing adsorption facility according to the present invention includes a deterioration adsorbent specifying step for specifying a region filled with the adsorbent deteriorated by the above-mentioned method for determining the deterioration status of the adsorbent according to the present invention, and the specified region. It is characterized by having an adsorbent exchange step for exchanging only the adsorbent filled in.

The region filled with the deteriorated adsorbent can be grasped by the above-mentioned method for determining the deterioration state of the adsorbent according to the present invention. As a result, only the deteriorated adsorbent can be replaced, and the cost can be suppressed to operate the pressure swing adsorbent.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples.

The effect of the present invention is demonstrated by using the two-tower type PSA experimental apparatus shown in FIG. 2 having the adsorption tower 1 (inner diameter 400 mm × height 255 mm, filling height of adsorbent A 200 mm) described in FIG. An experiment was conducted. As the adsorbent A, a commercially available 13X zeolite was used. Five, 10, and 20 temperature measurement points were provided with respect to the filling height of the adsorbent A, and the measurement points were arranged at equal intervals. The adsorption pressure was 50 kPaG, the desorption pressure was -95 kPaG, and the cycle times were 100 seconds and 300 seconds. As the raw material gas, a mixed gas having an N ₂ concentration of 41%, a CO ₂ concentration of 37%, a CO concentration of 1%, and an H ₂ concentration of 21% was used, and the flow rate was controlled to 3.0 NL / min by a mass flow controller (MFC). And supplied. Then, the target gas to be separated and recovered was CO ₂ , and the separation power of CO ₂ was calculated from the formula (A) using the mass of the separated and recovered CO ₂ .

FIG. 4 shows the temperature change ΔT of the adsorbent A for each measurement point when the cycle time is 100 seconds and FIG. 5 shows the cycle time of 300 seconds. In FIGS. 4 and 5, (a) shows the results for the case where the measurement points are 5 points, and FIG. 5 (b) shows the results for the case where the measurement points are 20 points.

Comparing FIG. 4A and FIG. 4B, there are a plurality of measurement points at which the temperature change ΔT of the adsorbent A becomes a constant value (ΔT _min ), and the region filled with the adsorbent A has a plurality of measurement points. It can be seen that the region where CO ₂ is adsorbed by the adsorbent is narrow. On the other hand, when FIG. 5A and FIG. 5B are compared, there are no multiple measurement points at which the temperature change of the adsorbent A becomes a constant value (ΔT _min ), and the adsorbent A is filled. It can be seen that CO ₂ is widely adsorbed in the region. The calculated CO ₂ separation power has a difference of 9% between the case of 5 measurement points and the case of 20 points, and 5% between the case of 10 points and the case of 20 points when the cycle time is 100 seconds. However, it was clarified that the difference between 5 points and 20 points was 2%, and the difference between 10 points and 20 points was 1% when the cycle time was 300 seconds. .. Therefore, by setting 20 points in the region showing the temperature change of the adsorbent A of ΔT _min or more and measuring the temperature, the CO ₂ separation power can be more accurately compared to the case where the measurement points are 5 points and 10 points. It turned out that it can be calculated.

When the cycle time was 300 seconds, two kinds of new 13X zeolite and used 13X zeolite were prepared as the adsorbent A, and PSA operation was carried out. In the filling region of the adsorbent A, there are three points: temperature change ΔT _s at a position 10 mm from the raw material gas supply port side, temperature change ΔT _c at the center position, and temperature change ΔT _m at a position 100 mm from the raw material gas discharge port. After measuring the temperature change, the relationship between the temperature change at each position, the recovery rate of CO ₂ which is the target gas, and the separation power was compared.

The measurement results show that when a new adsorbent is used, ΔT _s = 12 ° C, ΔT _c = 11 ° C, ΔT _m = 6 ° C, CO ₂ recovery rate = 70%, separation power = 0.19Wh / g-CO ₂ It became. On the other hand, when a used adsorbent was used, ΔT _s = 9 ° C, ΔT _c = 8 ° C, ΔT _m = 7 ° C, CO ₂ recovery rate = 60%, separation power = 0.21 Wh / g-. It became CO ₂ . From this result, it was confirmed that the adsorption performance of the adsorbent at the position 10 mm from the raw material gas supply port when the used adsorbent was used was deteriorated, and each position of the filling region of the adsorbent A was determined depending on whether the adsorbent was new or used. It was confirmed that the temperature change in the above fluctuated and the behavior as shown in FIG. 3 was exhibited.

Then, in the experiment using the used adsorbent, half of the filled area of the adsorbent A from the central position to the raw material gas supply port was replaced with a new adsorbent, and the experiment was performed again. As a result, ΔT _s = 12 ° C., ΔT _c = 10 ° C., ΔT _m = 6 ° C., CO ₂ recovery rate = 70%, separation power = 0.19 Wh / g-CO ₂ , and the entire amount of the new adsorbent was used. The result was the same as the case. In this way, it is possible to control the cost and operate the PSA equipment by grasping the deterioration status of the adsorbent by the method for determining the deterioration status of the adsorbent of the present invention and selectively replacing only the deteriorated adsorbent. Shows.

According to the present invention, when the target gas is separated from the raw material gas by the pressure swing adsorption method, the temperature of the adsorbent can be accurately measured at low cost by suppressing pressure loss.

1 Adsorption tower 11 Adsorption tower body 12 Thermocouple insertion tube 13 Thermocouple 14 Thermocouple position movement control means A Adsorbent B Beads S1, S2 Sponge

Claims (6)

It is a suction tower of pressure swing suction equipment.
The main body of the adsorption tower filled with an adsorbent that adsorbs the target gas component,
A thermocouple insertion tube installed over the entire length of the adsorption tower body parallel to the gas flow direction in the adsorption tower body.
A thermocouple inserted into the thermocouple insertion tube and measuring the temperature of the adsorbent in the main body of the adsorption tower.
Thermocouple position movement control means that moves the position of the thermocouple in the thermocouple insertion tube to allow the thermocouple to measure the temperature of the adsorbent at any position in the thermocouple insertion tube. When,
A suction tower characterized by having. The method for measuring the temperature of the adsorbent in the adsorbent according to claim 1.
The first temperature measurement step of measuring the temperature of the adsorbent in one cycle of the pressure swing at at least three measurement points along the gas flow direction in the adsorption tower main body.
A first adsorbent temperature change calculation step for calculating the temperature change ΔT of the adsorbent in one cycle of the pressure swing with respect to the temperature of the adsorbent measured in the first temperature measurement step.
A method for measuring the temperature of an adsorbent, which comprises. Of the temperature change ΔT obtained for each measurement point in the first adsorbent temperature change calculation step, the minimum adsorbent temperature change for determining the minimum adsorbent temperature change point in which the temperature change ΔT having the smallest value is measured is determined. Point determination step and
A plurality of measurement points are provided at equal intervals between the minimum adsorbent temperature change point determined in the minimum adsorbent temperature change point determination step and the measurement point on the most raw material gas supply port side in the adsorption tower main body. A second temperature measurement step of measuring the temperature of the adsorbent at each measurement point,
With respect to the temperature of the adsorbent measured in the second temperature measurement step, the second adsorbent temperature change calculation step for calculating the temperature change ΔT of the adsorbent in one cycle of the pressure swing, and the second adsorbent temperature change calculation step.
The method for measuring the temperature of an adsorbent according to claim 2, further comprising. It is a method of calculating the separation power of the target gas in the pressure swing adsorption method.
The specific heat _Cpads (J / kg · K) of the adsorbent, the mass _Mads (kg) of the adsorbent, the adsorption amount M _gas (kg) of the target gas, and the adsorbent in the adsorbent according to claim 2 or 3. Using the adsorbent temperature change ΔT (K) and the power conversion coefficient C measured by the temperature measuring method, the separation power W _gas (Wh / kg-gas) of the target gas was obtained using the following formula (A). A method for calculating the separation power of a target gas, which is characterized by calculation. Here, the electric power conversion coefficient C is a coefficient for converting energy (J) into electric energy (Wh).

It is a method of determining the deterioration status of the adsorbent in the pressure swing adsorption equipment.
The time change of the temperature change ΔT of the adsorbent at the measurement point in the adsorption tower main body is obtained by the method for measuring the temperature of the adsorbent in the adsorption tower according to claim 2 or 3.
Determining the deterioration status of the adsorbent, which is characterized in that it is determined that the adsorbent in the region where the temperature change ΔT has decreased from the start of gas separation is deteriorated at the stage when the predetermined target gas recovery rate cannot be achieved. Method. It is a method of operating the pressure swing suction equipment.
A deteriorated adsorbent specifying step for specifying a region filled with the adsorbent deteriorated by the method for determining the deterioration state of the adsorbent according to claim 5.
An adsorbent exchange step of exchanging only the adsorbent filled in the identified region, and an adsorbent exchange step.
A method of operating a pressure swing adsorption facility, characterized in that it has.

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