JP4146757B2 - Apparatus and method for measuring adsorption rate of carbonaceous adsorbent and adsorption processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for measuring an adsorption rate representing the adsorption characteristics of a predetermined substance of a carbonaceous adsorbent used in an exhaust gas treatment apparatus such as a dry desulfurization apparatus, and an adsorption treatment apparatus using the same.
[0002]
[Prior art]
As a treatment device for removing sulfur oxides (SOx) and the like in exhaust gas, a dry desulfurization device that treats exhaust gas by bringing it into contact with a carbonaceous adsorbent such as activated carbon is known. In this type of dry desulfurization apparatus, for example, activated carbon is allowed to flow in a container and brought into contact with exhaust gas, and the activated carbon that has adsorbed SOx is heated in an inert gas, so that the adsorbed SOx is desorbed and activated carbon is removed. The method of reproducing and reusing is adopted.
[0003]
Regeneration is indispensable because the amount of SOx adhering to the activated carbon saturates at a certain amount and it is impossible to adhere more than a predetermined amount of SOx. It is easy to invite breakthrough. On the other hand, the activated carbon in a state close to the saturation amount has a small amount of SOx adsorbed and the efficiency deteriorates. In order to prevent this, it is preferable to grasp the adsorption performance of a carbonaceous adsorbent such as activated carbon and adjust the amount of exhaust gas, the transfer rate of the carbonaceous adsorbent and the like accordingly.
[0004]
Therefore, a method for estimating the adsorption performance using a known adsorption rate equation or the adsorption property of a carbonaceous adsorbent to be used in advance is obtained, and an adsorption rate equation representing the adsorption property is obtained. A method of performing control is known (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP 200221411 A (paragraphs 0026 to 0039, FIGS. 2 to 5)
[0006]
[Problems to be solved by the invention]
However, when regeneration and reuse of the carbonaceous adsorbent are repeated, the adsorption characteristics gradually change depending on the cycle. For this reason, a deviation from the previously determined adsorption rate equation occurs, and a deviation also occurs in the estimated adsorption characteristic.
[0007]
Therefore, the present invention provides a carbonaceous adsorbent adsorption rate measuring apparatus and method capable of estimating the adsorption rate in accordance with the change in adsorption characteristics of the carbonaceous adsorbent due to such a use cycle, and an adsorber using the same. This is the issue.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, an adsorption rate measuring apparatus for a carbonaceous adsorbent according to the present invention is an adsorption processing apparatus for adsorbing a predetermined substance in exhaust gas to a carbonaceous adsorbent for processing. A sampling device for extracting a predetermined amount of carbonaceous adsorbent as a sample from a predetermined position of the adsorption processing device, and passing a gas having a predetermined concentration of the predetermined substance through the sample, and in the exhaust gas after passing A gas flow test device for measuring a concentration change of a predetermined substance, and a control calculation unit for calculating an adsorption rate formula based on data obtained from the gas flow test device or correcting a preset adsorption rate formula It is characterized by.
[0009]
Further, the adsorption processing apparatus according to the present invention includes a sampling apparatus for extracting a predetermined amount of carbonaceous adsorbent as a sample in a circulation path for circulating the carbonaceous adsorbent from the adsorption processing apparatus via the desorption / regeneration apparatus, and a sample. Based on data obtained from a gas flow test device that passes a gas with a predetermined concentration of a predetermined material at a predetermined flow rate and measures the change over time of the concentration of the predetermined material in the exhaust gas after passing through the gas flow test device And a control calculation unit that calculates an adsorption rate equation or corrects a preset adsorption rate equation .
[0010]
Furthermore, the method for measuring the adsorption rate of a carbonaceous adsorbent according to the present invention comprises a sampling step of extracting a predetermined amount of carbonaceous adsorbent as a sample from a predetermined position of an adsorption processing apparatus, and a gas having a known concentration of a predetermined substance in the sample. A gas passing test step of measuring the concentration change of a predetermined substance in the exhaust gas after passing through, and calculating an adsorption rate equation based on data obtained from the gas passing test device or a preset adsorption rate equation And a control calculation step for correction.
[0011]
According to the present invention, a gas passing test is performed using a carbonaceous adsorbent sampled from an exhaust gas treatment device (adsorption device) in use, and a new adsorption rate equation is calculated based on the test result or preset. Since the adsorption rate equation is corrected, it is possible to more accurately simulate the adsorption characteristics of the carbonaceous adsorbent used.
[0012]
It is preferable to use a plurality of samples and perform the measurement by the gas flow test apparatus in parallel by changing the concentration or flow rate of the predetermined substance. In this way, the calculation of the adsorption rate equation or the correction accuracy can be improved.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.
[0014]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an overall configuration diagram of an exhaust gas treatment apparatus that employs an adsorption rate measurement apparatus according to the present invention as one of control measurement apparatuses. This exhaust gas treatment device is a dry desulfurization device that mainly removes SOx contained in exhaust gas.
[0015]
The exhaust gas treatment device is filled with activated carbon as a carbonaceous adsorbent, and adsorbs and removes the contaminants (mainly SOx) in the exhaust gas to be passed through, and the cross-flow moving bed type adsorption treatment device 1 and the activated carbon after SOx adsorption. A desorption / regeneration device 2 is provided that desorbs SOx and the like adsorbed by heating to regenerate activated carbon. The adsorption treatment device 1 and the desorption / regeneration device 2 are connected by a line L11, and on this line L11, an activated carbon flow meter 11 for measuring the flow rate of activated carbon from the adsorption treatment device 1 and the flow rate thereof. A flow rate adjusting valve 12 to be adjusted is arranged.
[0016]
A separator 3 for sieving the activated carbon powdered from the activated carbon is connected to the activated carbon outlet of the desorption / regeneration apparatus 2 via a line L12. The separator 3 is connected to the adsorption device 1 via lines L13 and L14, and constitutes an activated carbon circulation path of adsorption device 1 → desorption regeneration device 2 → separator 3 → adsorption device 1. The separator 3 is connected to a line L15 for discharging the separated powdered activated carbon and the like. In addition, a sampling device 4 is arranged between the line L13 and the line L14 to extract a predetermined amount of circulating activated carbon, extract it as a sample, and return it to the circulation path after a predetermined gas flow test. The sampling device 4 is connected to an adsorption rate measuring device 5 according to the present invention which performs a gas passage test and calculates an adsorption rate by a line L16 which is a circulation path.
[0017]
An SOx concentration meter 13 for measuring the SOx concentration of the exhaust gas and a gas flow meter 14 for measuring the exhaust gas flow rate are arranged on the line L1 for supplying the exhaust gas to the adsorption processing apparatus 1. A line L3 for supplying exhaust gas to the adsorption rate measuring device 5 is branched from the line L1 upstream of the SOx concentration meter 13 and the gas flow meter 14, and a return gas line L4 from the adsorption rate measuring device 5 is connected. Yes. Then, the output signals of the activated carbon flow meter 11, the SOx concentration meter 13, the gas flow meter 14 and the adsorption rate measuring device 5 are sent to the activated carbon flow control device 6 that controls the opening degree of the flow rate adjusting valve 12.
[0018]
FIG. 2 is a schematic configuration diagram of the adsorption rate measuring device 5 according to the present invention. This adsorption rate measuring device is composed of a control calculation unit 51 and one or a plurality of gas flow test devices 50 (50 ₁ to 50 _n ).
[0019]
The gas flow test device 50 is a device that examines the adsorption characteristics of activated carbon by ventilating the sample gas through the activated carbon in the sample cell 510. The sample cell 510 contains activated carbon sampled by the sampling device 4 in an airtight state. Although the sample cell 510 is held in the thermostatic chamber 54, the thermostatic chamber 54 may be common to all the gas flow test devices as shown in FIG. 2 or may be provided for each gas flow test device 50. Either is acceptable.
[0020]
A sample gas supply line L50 connected to the line L3 and a sample gas discharge line L51 connected to the line L4 are connected to the sample cell 510. An air supply line L52 extending from the air cylinder 52 and an SO ₂ line L53 extending from the SO ₂ cylinder 53 are connected to the line L50 via flow rate adjusting valves 520 and 530, respectively. A regulating valve 540, a gas flow meter 550, and a SOx concentration meter 560 are disposed. On the other hand, a SOx densitometer 570 is arranged in the line L51. The output signal of the gas flow meter 550 is input to the flow rate control device 501 that controls the opening degree of the flow rate adjustment valve 540, and the output signal of the SOx concentration meter 560 indicates the opening degree of the flow rate adjustment valves 520 and 530. It is connected to the SOx concentration control device 502 to be controlled. The output signal of the SOx concentration meter 570 is input to the control calculation unit 51 that controls the flow rate control device 501 and the SOx concentration control device 502 and calculates the adsorption rate.
[0021]
The exhaust gas treatment apparatus of FIG. 1 operates as follows. Exhaust gas containing SOx is introduced into the adsorption treatment apparatus 1 from the line L1. The activated carbon filled in the adsorption processing device 1 is pulled out from the lower portion by a predetermined amount by the activated carbon flow rate control device 6 controlling the flow rate adjusting valve 12, and almost the same amount is returned from the separator 3 vertically downward. To form a moving bed. The sampling device 4 provided in the middle of the return path (L13, L14) samples a predetermined amount of activated carbon at a predetermined interval and sends it to the gas passing test device 50 of the adsorption rate measuring device 5. And it also has a role which returns the activated carbon returned from the gas flow test apparatus 50 to the line L14. The exhaust gas is introduced in a direction perpendicular to the flow direction of the moving bed and comes into contact with the activated carbon, so that SOx in the exhaust gas is adsorbed and removed by the activated carbon. The exhaust gas thus purified is discharged from the apparatus through a line L2.
[0022]
The activated carbon that has adsorbed SOx is sent to the desorption / regeneration device 2 through line L11, and is regenerated by desorbing the adsorbed SOx by being heated in an inert gas. The activated carbon thus regenerated is sent to the separator 3 via the line L12, and after the powdered activated carbon is separated, it is returned to the adsorption processing apparatus 1 via the lines L13 and L14. It is preferable to add an amount of new activated carbon corresponding to the powdered activated carbon in any of the paths L11 to L14.
[0023]
On the other hand, the activated carbon extracted by the sampling device 4 is introduced into the sample cell 510 of the gas flow test device 50 and is kept at a predetermined temperature in the thermostatic chamber 54. A gas having a predetermined flow rate and SOx concentration is introduced into the sample cell 510 via a line L50, and the SOx in the gas is adsorbed by the activated carbon in the sample cell 510. Then, by measuring the SOx concentration of the gas that has passed through the sample cell 510 using the SOx concentration meter 570, the time change of the adsorption amount of the activated carbon with respect to the gas having a predetermined flow rate and SOx concentration is measured, and the adsorption rate characteristic curve Get f (t).
[0024]
In the present embodiment, the exhaust gas introduced from the line L3 is mixed with air via the air cylinders 52 to L52 and SOx gas via the SOx cylinders 53 to L53, and the SOx concentration control device 502 controls the flow control valves 520 and 530. Is controlled to adjust the mixing ratio, thereby adjusting the SOx concentration to a predetermined value. Further, the gas flow rate is adjusted to a predetermined value by controlling the flow rate adjustment valve 540 by the flow rate control device 501. Of course, a gas having a predetermined SOx concentration and flow rate may be supplied to the sample cell by mixing the SOx gas and air introduced from the SOx cylinder and air cylinder without using exhaust gas.
[0025]
The control calculation unit 51 uses an adsorption rate equation v (d, q) representing the adsorption rate v as a function with the gas concentration d and the current adsorption amount q as variables by fitting from a plurality of adsorption rate characteristic curves f (t). Ask for. When there is one gas flow test device 50, it is necessary to perform measurement sequentially with different gas concentrations. However, when there are a plurality of gas flow test devices 50, the gas is measured using activated carbon sampled at the same time. Since adsorption rate characteristic curves can be obtained in parallel under different conditions of concentration and flow rate, it is more preferable. The adsorption rate equation v (d, q) thus determined is sent to the activated carbon flow rate control device 6. Further, instead of newly obtaining the adsorption rate equation v (d, q) by fitting, a preset adsorption rate equation v (d, q) may be corrected sequentially.
[0026]
In this exhaust gas treatment device, the activated carbon flow rate control device 6 adjusts the amount of activated carbon extracted from the adsorption treatment device 1 via the flow rate adjustment valve 12, thereby ensuring the desulfurization rate and the target exhaust concentration, and the adsorption treatment of activated carbon. The life of the activated carbon is extended by increasing the residence time in the apparatus 1. Hereinafter, the control method will be described.
[0027]
FIG. 3 shows a simulation model of the adsorption processing apparatus 1 used for control, and FIG. 4 is a flowchart of the control. The following control is performed for each time step.
[0028]
In this control, the SOx adsorption amount distribution on the activated carbon in the adsorption processing apparatus 1 is obtained and used for the control. When obtaining this adsorption amount distribution, the model of the adsorption device 1 shown in FIG. 3 is used. In this model, the moving bed in the adsorption device 1 is divided into L pieces in the flow direction of the activated carbon, and divided into M pieces in the flow direction of the exhaust gas orthogonal to this, and divided into a total of L × M cells. . Then, the most upstream cell in each flow direction is defined as cell (1, 1), and the most downstream cell is defined as cell (L, M). The current SOx adsorption amount of the cell (j, k) (1 ≦ j ≦ L, 1 ≦ k ≦ M) is represented by q [j, k].
[0029]
First, as shown in FIG. 4, in step S <b> 1, the exhaust gas flow rate F sent from the gas flow meter 14, the exhaust gas inlet SOx concentration S_in sent from the SOx concentration meter 13, and the activated carbon flow meter 11 sent. Load each of the activated carbon removal amounts Q. In step S2, the previous SOx adsorption amount distribution q (representing an array consisting of q [1,1] to q [L, M]) (in the previous time step) is based on these values. Update. By performing this update using the SOx adsorption rate equation v (d, q) obtained by the adsorption rate measuring device 5, the adsorption rate equation v (d, q) can be adjusted according to the change in the adsorption characteristics of the activated carbon by the use cycle. Since it has been updated, it is possible to more accurately simulate the adsorption characteristics of actual activated carbon.
[0030]
Subsequently, in step S3, the planned exhaust gas flow rate F ^# from the plant operation plan to a predetermined time in the future and the planned SOx concentration S_in ^# in the exhaust gas are read. These F ^# and S_in ^# are composed of n arrays. If the capacity of the adsorption device 1 is V and the maximum activated carbon flow rate is Qmax, F ^# [i] and S_in ^# [i] are the planned exhaust gas flow rate and the planned SOx concentration in the exhaust gas at the time step after iV / nQ, respectively. To express. In step S4, a target value S_out ^* of the SOx concentration in the exhaust gas at each time step is set.
[0031]
In step S5, the target activated carbon flow rate Q_sv is calculated. Here, the simulation calculation of the future desulfurization state, that is, the time change of the activated carbon adsorption amount distribution until the activated carbon present in the adsorption apparatus 1 is almost replaced, and the residence of activated carbon at which the outlet SOx concentration is almost saturated. The activated carbon flow rate Q_sv is calculated under conditions where the time can be taken as long as possible and the outlet SOx concentration can achieve the target. In step S6, the flow rate adjustment valve 14 is controlled to adjust the flow rate so that the activated carbon flow rate becomes Q_sv set in this way.
[0032]
In the above description, the SOx treatment has been described as an example, but the present invention can also be applied to other harmful substances treated by adsorption. The substance to be filled in the adsorption device is not limited to activated carbon, and activated carbon, activated coke, activated char obtained by oxidizing coal, etc. with heat treatment, heat treatment or steam, etc., and vanadium, iron, manganese Those carrying a metal compound such as can also be used. Further, the adsorption rate measuring device of the present invention is not limited to the above control, and can be applied to various types of control using the adsorption rate.
[0033]
【The invention's effect】
As described above, according to the present invention, the activated carbon actually used is sampled and its adsorption rate characteristic is measured by the gas test device, and the adsorption rate is changed by the use cycle based on the measurement. Therefore, it is possible to more accurately simulate the adsorption speed distribution and the like in the adsorption processing apparatus, and to perform highly accurate control.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a dry desulfurization apparatus using an adsorption rate measuring apparatus according to the present invention in a measurement system.
FIG. 2 is a schematic configuration diagram of a main body portion of the adsorption rate measuring apparatus according to the present invention.
FIG. 3 is a view showing a simulation model of an adsorption distribution in the dry desulfurization apparatus of FIG. 1;
4 is a flowchart showing a control flow of the apparatus of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Adsorption processing apparatus, 2 ... Desorption reproduction | regeneration apparatus, 3 ... Separator, 4 ... Sampling apparatus, 5 ... Adsorption rate measuring apparatus, 6 ... Activated carbon flow control apparatus, 11, 14, 550 ... Flowmeter, 12, 520, 530, 540 ... Flow rate adjusting valve, 13, 560, 570 ... SOx concentration meter, 50 ... Gas communication test device, 51 ... Control calculation unit, 52 ... Air cylinder, 53 ... SOx cylinder, 54 ... Constant temperature bath, 501 ... Flow control Apparatus 502 ... SOx concentration control apparatus 510 ... Sample cell.

Claims (4)

An apparatus for measuring the adsorption rate of the carbonaceous adsorbent in an adsorption treatment apparatus for adsorbing and processing a predetermined substance in exhaust gas to the carbonaceous adsorbent,
A sampling device for extracting a predetermined amount of carbonaceous adsorbent as a sample from a predetermined position of the adsorption processing device;
A gas flow test device for allowing a gas having a known concentration of the predetermined substance to pass through the sample and measuring a change in the concentration of the predetermined substance in the exhaust gas after the passage;
A control calculation unit that calculates an adsorption rate equation based on data obtained from the gas flow test device or corrects a preset adsorption rate equation ;
An apparatus for measuring an adsorption rate of a carbonaceous adsorbent, comprising:   2. The carbonaceous adsorbent adsorption rate measuring apparatus according to claim 1, wherein a plurality of the samples are used to perform measurement by the gas flow test apparatus in parallel. An adsorption treatment apparatus for treating a predetermined substance in exhaust gas by adsorbing to a carbonaceous adsorbent,
A sampling device for extracting a predetermined amount of the carbonaceous adsorbent as a sample in a circulation path for circulating the carbonaceous adsorbent from the adsorption processing device via the desorption / regeneration device ;
A gas passing test device for allowing a gas having a predetermined concentration of the predetermined substance to pass through the sample at a predetermined flow rate, and measuring a time change of the concentration of the predetermined substance in the exhaust gas after passing;
A control calculation unit that calculates an adsorption rate formula based on data obtained from the gas flow test device or corrects a preset adsorption rate formula ;
An adsorption processing apparatus comprising: A method for measuring the adsorption rate of the carbonaceous adsorbent in exhaust gas treatment in which a predetermined substance in the exhaust gas is adsorbed on the carbonaceous adsorbent for treatment,
A sampling step of extracting a predetermined amount of carbonaceous adsorbent as a sample from a predetermined position of the adsorption processing device;
A gas passing test step of allowing a gas having a known concentration of the predetermined substance to pass through the sample and measuring a change in the concentration of the predetermined substance in the exhaust gas after passing;
A control calculation step of calculating an adsorption rate equation based on data obtained from the gas flow test device or correcting a preset adsorption rate equation ;
A method for measuring the adsorption rate of a carbonaceous adsorbent, comprising:

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