JP2014100670A - Method for stable acidic gas treatment and combustion exhaust gas treatment facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for a stable acidic gas treatment and a combustion exhaust gas treatment facility that appropriately control an addition amount of two alkali agents with mutually different characteristics to be added to an acidic gas.SOLUTION: A combustion exhaust gas treatment facility 10 applied with the method for a stable acidic gas treatment comprises: a first adding device 42 and a second adding device 44 provided in an introduction passage 3; an acidic gas measurement device 30 provided in an exhaust passage 4; and an addition amount control device 50. The addition amount control device 50 includes: a first addition amount calculation section 60 that receives an acidic gas density signal S0 and outputs a first addition amount signal S21; and a second addition amount calculation section 70 that receives the first addition amount signal S21 and outputs a second addition amount signal S22. The first adding device 42 and the second adding device 44 on the basis of the first addition amount signal S21 and the second addition amount signal S22 respectively add a first alkali agent and a second alkali agent to a combustion exhaust gas flowing in the introduction passage 3.

Description

  The present invention stabilizes combustion exhaust gas containing acidic gases such as harmful hydrogen chloride and sulfur oxide generated in combustion facilities such as municipal waste waste incinerators, industrial waste incinerators, power generation boilers, carbonization furnaces, private factories, etc. More specifically, the present invention relates to a combustion exhaust gas stabilization treatment method and a combustion exhaust gas treatment facility that efficiently controls the amount of an alkaline agent added to treat acid gas.

Combustion exhaust gas generated in combustion furnaces of municipal waste incinerators, industrial waste incinerators, power generation boilers, carbonization furnaces, private factories, etc., is treated with acidic gases such as harmful hydrogen chloride gas and sulfur oxide gas. Including. The combustion facility adds an alkaline agent such as slaked lime or baking soda to the acid gas, and then removes the dust with a dust collector such as a bag filter, after which it is discharged from the chimney with almost no harmful acid gas. The
The fly ash collected by the dust collector contains harmful heavy metals such as palladium (Pd) and cadmium (Cd). These harmful heavy metals are stabilized and then landfilled at the final disposal site (see, for example, Patent Document 1).

  Slaked lime for treating acid gas has the property that the reaction rate with hydrogen chloride gas increases with the concentration of hydrogen chloride gas (see, for example, Non-Patent Document 1), but the reactivity with acid gas is low and sulfur oxidation is performed. Reactivity with the product is particularly low.

  Sodium bicarbonate, which is an alkaline agent for treating acid gas, has a higher reactivity with acid gas than slaked lime, and sodium bicarbonate finely processed to 5 to 30 μm has a particularly high reactivity with acid gas (for example, patents). Reference 2). In other words, baking soda can stably treat acidic gas, and there is little unreacted content of acidic gas. Therefore, even if the concentration of acid gas fluctuates drastically, by adding an appropriate amount of baking soda according to the concentration of acid gas, the amount of sodium bicarbonate added can be reduced while stably treating the acid gas. it can. For this reason, since the amount of the collected fly ash and hence the landfill disposal amount can be reduced, adding sodium bicarbonate to the acid gas is an effective means for reducing the environmental load.

JP-A-9-99215 JP 2000-218128 A

Published by Japan Society for Chemical Engineering, Journal of Chemical Engineering 33 (2), 154-159, 2007-03-20 (http://ci.nii.ac.jp/naid/100189903497)

  By the way, in general, the concentration of acid gas discharged from a combustion furnace such as an industrial waste incinerator or a private factory varies greatly. Although slaked lime is economically cheap, the reaction with acid gas is slow and the reaction with sulfur oxide is particularly slow. For this reason, it is difficult to apply the method of adding only slaked lime to acid gas to industrial waste incinerators, private factories and the like where the concentration of acid gas varies greatly.

  Baking soda has a high reactivity with the acid gas and a fast reaction, so that the acid gas can be treated stably. However, baking soda is more expensive than slaked lime. For this reason, when the method of adding only baking soda to acid gas and stably treating it is applied to industrial waste incinerators, private factories and the like that generate a large amount of acid gas, the economic burden increases.

  An object of the present invention is to provide an acid gas stable treatment method and a combustion exhaust gas treatment facility that appropriately control the addition amounts of two alkaline agents having different properties added to an acid gas.

  The inventors calculated the addition amount of the first alkaline agent based on the information on the acid gas, and the addition amount of the second alkaline agent is the addition amount of the first alkaline agent among the two alkaline agents having different properties. It was calculated based on the above information, and it was found that the above-mentioned object was achieved by adding the alkali agent in the added amount to the acidic gas, and the present invention was completed.

The present invention provides the following.
The stable treatment method according to the present invention stably treats flue gas containing acid gas at a flue gas treatment facility. The stable treatment method includes an acid gas concentration measurement step for measuring the acid gas concentration in the treated flue gas after treating the flue gas with a dust collector, and acid gas information that is information on the acid gas based on the acid gas concentration And calculating a normal addition amount of the first alkaline agent based on the acid gas information, calculating a first addition amount based on the normal addition amount, and a first addition relating to the first addition amount. A second calculation step of calculating a second addition amount of the second alkaline agent based on the quantity information; a first addition step of adding the first addition amount of the first alkaline agent to the treated combustion exhaust gas; A second addition step of adding the second addition amount of the second alkaline agent to the post-treatment combustion exhaust gas.

  The first addition amount information includes an average first addition amount of the first addition amount at a predetermined time, and the second calculation step includes calculating an average of the second addition amount at the predetermined time from a past second addition amount. Calculating second addition amount information including the second addition amount, and calculating the second addition amount based on the average first addition amount, the average second addition amount, and a predetermined target addition amount; preferable.

  The acid gas information includes an acid gas concentration amount that represents a change rate of an instantaneous acid gas concentration that is a real-time acid gas concentration measured in the acid gas concentration measurement step, and the first calculation step includes the acid gas concentration The normal addition amount is preferably corrected based on a predetermined correction method according to the concentration amount.

  The stable processing method prescribes basic addition amount correspondence information that relates the instantaneous acid gas concentration and the addition amount of the first alkaline agent in advance, and the first calculation step includes a state where the acid gas concentration amount is constant. Is maintained or decreased, the normal addition amount is calculated based on the instantaneous acid gas concentration and the basic reduction addition amount correspondence information, and the acid gas concentration amount increases. In the case of a rising state, the normal addition amount is calculated based on the instantaneous acid gas concentration and the addition amount correspondence information for increase in which the acid gas concentration value in the basic addition amount correspondence information is reduced by a predetermined correction method. It is preferable to do.

  In the first calculation step, when the acid gas concentration amount is in a descending state where the state is constant or decreasing, the normal addition amount is corrected to be in a range of more than 0 and less than 1. It is preferable to correct the value.

  A plurality of corresponding addition amount upper limit values are provided between the maximum addition amount and the minimum addition amount that can be added in the first addition step, and the plurality of corresponding addition amount upper limit values respectively correspond to a plurality of acid gas concentrations. The acidic gas information includes an instantaneous acidic gas concentration that is an acidic gas concentration measured in the acidic gas concentration measuring step, and the first calculating step includes determining that the instantaneous acidic gas concentration is the plurality of acidic gas concentrations. When the acid gas concentration is within the range of two adjacent acid gas concentrations, the normal addition amount is calculated based on the corresponding addition upper limit corresponding to the higher concentration of the two adjacent acid gas concentrations. It is preferable.

  The acidic gas information includes an average acidic gas concentration that is an average value of the acidic gas concentration in a predetermined time, and the first calculation step is performed when the average acidic gas concentration exceeds a predefined emergency addition concentration, Instead of the normal addition amount, it is preferable to calculate the first addition amount based on the emergency addition amount defined in advance.

  The acidic gas includes hydrogen chloride gas and sulfur oxide gas, and the acidic gas concentration measuring step includes a hydrogen chloride gas concentration measuring step of measuring the hydrogen chloride gas concentration in the acidic gas, and the acidic gas in the acidic gas. A sulfur oxide concentration measuring step for measuring a sulfur oxide concentration, wherein the acid gas information includes hydrogen chloride information related to the hydrogen chloride gas and sulfur oxide information related to the sulfur oxide gas, and In the calculating step, the normal addition amount is calculated based on the hydrogen chloride gas addition amount calculated based on the hydrogen chloride information, the sulfur oxide gas addition amount calculated based on the sulfur oxide information, and the basic addition amount. Preferably, the basic addition amount is calculated based on an average addition amount of the first addition amount at a predetermined time.

  It is preferable that the first alkaline agent is an alkaline agent containing at least 5 to 30 μm fine powdered sodium bicarbonate, and the second alkaline agent is an alkaline agent containing at least slaked lime.

  The stabilization treatment method preferably further includes an immobilization treatment step of adding at least one selected from an iron-based compound, a phosphoric acid-containing compound, and a neutralizing agent to the fly ash collected in the dust collector. .

  The combustion exhaust gas treatment facility according to the present invention executes the acid gas stabilization treatment method described above. The flue gas treatment facility executes a dust collector, an introduction path for introducing the flue gas into the dust collector, an exhaust path for discharging the treated flue gas treated by the dust collector from the dust collector, and the acid gas concentration measurement step And an oxidant gas measuring device that outputs the oxidant gas information signal, and a first additive amount that executes the first calculation step based on the oxidant gas information signal and outputs the first additive amount as the first additive amount signal. An addition amount control device including a calculation unit and a second addition amount calculation unit that executes the second calculation step based on the first addition amount signal and outputs the second addition amount as a second addition amount signal; A first addition device that executes the first addition step based on the first addition amount signal; and a second addition device that executes the second addition step based on the second addition amount signal.

  ADVANTAGE OF THE INVENTION According to this invention, the acidic gas stable processing method and combustion exhaust gas treatment facility which control appropriately the addition amount of two alkaline agents with a mutually different property added to acidic gas can be provided.

It is a conceptual diagram which shows the acidic gas stabilization processing method and combustion exhaust gas treatment facility which concern on this invention. It is a detailed conceptual diagram of a part of the acid gas stabilization method and the combustion exhaust gas treatment facility shown in FIG. FIG. 2 is a detailed conceptual diagram of another part of the acid gas stabilization method and the combustion exhaust gas treatment facility shown in FIG. 1. It is a graph which shows the acid gas stable processing method shown in FIG. 1 and the basic addition amount corresponding | compatible information of a combustion exhaust gas treatment facility, and its correction | amendment. It is a graph which shows the basic addition amount corresponding | compatible information of the acidic gas stable processing method and combustion exhaust gas processing facility shown in FIG. 1, and its another correction | amendment. It is a flowchart explaining the acidic gas stable processing method shown in FIG. It is a flowchart explaining the acidic gas stabilization processing method following FIG. It is a graph which shows the result of a comparative example. 3 is a graph showing the results of Example 1. 10 is a graph showing the results of Example 2. It is a time series graph which shows the result of a comparative example. 3 is a time series graph showing the results of Example 1. FIG. 6 is a time series graph showing the results of Example 2.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In addition, although an embodiment is given and demonstrated concretely below, this invention is not limited to this.

  As shown in FIGS. 1 to 3, a combustion exhaust gas treatment facility 10 to which the acid gas stabilization method according to the present invention is applied includes, for example, a municipal waste incinerator, an industrial waste incinerator, a power generation boiler, and a carbonization furnace. It is a combustion facility such as a private factory. The combustion exhaust gas treatment facility 10 combusts combustibles such as municipal waste, generates a high-temperature combustion exhaust gas containing harmful acid gas, a boiler 14 that uses the heat of the combustion exhaust gas, and combustion exhaust gas A temperature-decreasing tower 16 for reducing heat, one or more dust collectors 18, a chimney 22 for exhausting the exhaust gas after treatment by treating the exhaust gas with the dust collector 18, and a fly ash accumulator for collecting the removed fly ash 19.

  The combustion exhaust gas treatment facility 10 includes a pipe 2 that sends high-temperature combustion exhaust gas generated in the combustion furnace 12 to the temperature reduction tower 16 via the boiler 14, and an introduction path 3 that connects the temperature reduction tower 16 to the dust collector 18. And the discharge path 4 connected to the chimney 22 from the dust collector 18. When the combustion exhaust gas treatment facility 10 includes a plurality of dust collectors 18, the end of the introduction path 3 refers to the position of the dust collector 18 provided at a position farthest from the temperature reducing tower 16 among the plurality of dust collectors 18.

  The combustion exhaust gas treatment facility 10 efficiently sends the combustion exhaust gas in the pipe 2 and the introduction passage 3 to the dust collector 18, and the exhaust passage 4 so as to efficiently exhaust the treated combustion exhaust gas in the discharge passage 4 from the chimney 22. A fan 20 is provided.

  The combustion exhaust gas treatment facility 10 further includes a first addition device 42 and a second addition device 44 provided in the introduction path 3 for stabilizing the acidic gas in the combustion exhaust gas discharged from the combustion furnace 12, An acid gas measuring device 30 provided in the discharge path 4 and an addition amount control device 50 are included.

  The first addition device 42 is an addition device that adds the first alkaline agent to the combustion exhaust gas flowing in the introduction path 3 based on the first addition amount signal S21 from the addition amount control device 50. The second addition device 44 is an addition device that adds the second alkaline agent to the combustion exhaust gas flowing in the introduction path 3 based on the second addition amount signal S22 from the addition amount control device 50. Therefore, the second addition device 44 adds the second alkaline agent to the introduction path 3 in accordance with the amount of the first alkaline agent added by the first addition device 42.

Since the first alkaline agent is added for the purpose of proper treatment of the acidic gas, the type thereof is not particularly limited, but an alkaline agent having a relatively high reactivity with the acidic gas is preferable. Examples of the first alkaline agent include fine powdered baking soda adjusted to an average particle size of 5 to 30 μm and highly reactive slaked lime having a specific surface area of 30 m ² / g or more. In particular, fine powdered baking soda with an average particle size of 5 to 30 μm is highly reactive not only with hydrogen chloride but also with sulfur oxides. Is preferred. In addition, these alkali agents such as baking soda may be used by pulverizing a coarse particle alkali agent on site.

Since the second alkali agent is added for the purpose of roughening the acid gas, the type thereof is not particularly limited, but the reactivity with the acid gas may be relatively low, and an inexpensive alkali agent is economical. Is preferred. Examples of the second alkaline agent include JIS special slaked lime, highly reactive slaked lime with a specific surface area of 30 m ² / g or more, sodium hydroxide, crude sodium bicarbonate, sodium sesquicarbonate, natural soda, magnesium oxide, magnesium hydroxide and the like. it can. The second alkaline agent may be a slurry or an aqueous solution in which each alkaline agent is dissolved in water.

In the case where the second alkaline agent is slaked lime, the second alkaline agent may be added so as to be 0.5 to 3 equivalents, preferably 1 to 2 equivalents per acid gas concentration (HCl, SO ₂ ) generated. preferable.
When the first alkaline agent is fine powdered sodium bicarbonate, the first alkaline agent is 0 per acid gas concentration (HCl, SO ₂ ) generated so that both hydrogen chloride and sulfur oxide can be stably treated. .10 to 0.60 equivalent, preferably 0.15 to 0.50 equivalent.

  The first addition device 42 and the second addition device 44 only need to be provided in the introduction path 3. For example, in the acid gas flow direction W, the first addition device 42 is upstream of the second addition device 44. The second addition device 44 may be on the upstream side of the first addition device 42.

  The dust collector 18 is, for example, a bag filter that removes fly ash from combustion exhaust gas. When the combustion exhaust gas treatment facility 10 includes a plurality of dust collectors 18, the second addition device 44 is provided on the upstream side of the first addition device 42 in the introduction path 3 so that the acidic gas is appropriately processed, and the plurality of dust collectors 18. One of them is preferably provided between the first addition device 42 and the second addition device 44, and the other one is preferably provided downstream of the first addition device 42.

  The acid gas measuring device 30 measures the acid gas concentration in the treated flue gas after treating the flue gas with the dust collector 18, and outputs the measured acid gas concentration as the acid gas concentration signal S0. Specifically, the acid gas measurement device 30 includes a hydrogen chloride gas concentration measurement device 32 and a sulfur oxide gas concentration measurement device 34. The hydrogen chloride gas concentration measuring device 32 measures the instantaneous hydrogen oxide gas concentration, which is the real-time hydrogen chloride gas concentration in the treated exhaust gas after flowing through the discharge passage 4, and uses the measured instantaneous hydrogen chloride gas concentration as the hydrogen chloride gas. Output as the density signal S1. Similarly, the sulfur oxide gas concentration measuring device 34 measures the instantaneous sulfur oxidation shoe gas concentration, which is the real-time sulfur oxide gas concentration in the post-treatment combustion exhaust gas flowing in the discharge passage 4, and the measured instantaneous sulfur oxidation. The product gas concentration is output as a sulfur oxide gas concentration signal S2.

The hydrogen chloride gas concentration measuring device 32 and the sulfur oxide gas concentration measuring device 34 may be any measuring device that can measure the hydrogen chloride gas concentration and the sulfur oxide gas concentration, respectively, and the type of the measuring device is not limited. Hydrogen chloride gas concentration can be measured by ion electrode method, laser single absorption line absorption spectroscopy, etc., and sulfur oxide gas concentration can be measured by non-dispersive infrared absorption method, ultraviolet fluorescence method, etc. .
Further, the combustion exhaust gas treatment facility 10 normally has a hydrogen chloride gas concentration signal S1 of the hydrogen chloride gas concentration measuring device 32 installed in the discharge passage 4 and a sulfur oxide gas concentration signal of the sulfur oxide gas concentration measuring device 34. Since the addition amount of the first alkaline agent is feedback-controlled according to S2, the addition amount of the first alkaline agent and the second alkaline agent without installing a new measuring device in the conventional flue gas treatment facility Can be controlled appropriately.

The addition amount control device 50 receives the acid gas concentration signal S0 so that feedback control can be performed to set the acid gas concentration (ppm) to a control target value (also referred to as control output start concentration) SV (ppm) or less. A first addition amount calculation unit 60 that outputs an addition amount signal S21 and a second addition amount calculation unit 70 that receives the first addition amount signal S21 and outputs a second addition amount signal S22.
The first addition amount signal S21 indicates the first addition amount (kg / h) per unit time of the first alkaline agent added by the first addition device 42. The second addition amount signal S22 indicates the second addition amount (kg / h) per unit time of the second alkaline agent added by the first addition device 42.
The addition amount control device 50 determines the first addition amount signal based on the acid gas concentration of the acid gas concentration signal S0 so that the acid gas concentration (ppm) of the treated combustion exhaust gas is equal to or less than the control target value SV (ppm). S21, the second addition amount signal S22 is output.

Here, in general, a hydrogen chloride gas concentration measuring device is mainly a device employing an ion electrode method having a long measurement delay time of 5 to 10 minutes. In general, a sulfur oxide gas concentration measuring device mainly uses an infrared absorption method with a measurement delay time of 3 to 5 minutes.
The addition amount control device 50 includes a measurement delay time of the hydrogen chloride gas concentration measurement device 32 and the sulfur oxide gas concentration measurement device 34, an addition delay time from the first addition device 42 and the second addition device 44 to the introduction path 3, and the like. As the delay time increases, the feedback control may be adversely affected, and the amounts of the first alkaline agent and the second alkaline agent added by the first addition device 42 and the second addition device 44 may be increased.
Therefore, as will be described later, the addition amount control device 50 performs stabilization control based on the measurement delay time in consideration of the measurement delay time and the time required for feedback control calculation.

  The first addition amount calculation unit 60 includes a main addition amount calculation unit 61, a basic addition amount calculation unit 63, a normal addition amount calculation unit 64, an emergency determination unit 65, a temporary addition amount calculation unit 66, and an equipment addition A quantity limiting unit 67.

  The main addition amount calculation unit 61 calculates the basic addition amount of the first alkaline agent based on the acid gas concentration signal S0. The main addition amount calculation unit 61 includes a hydrogen chloride gas calculation unit 62a that receives the hydrogen chloride gas concentration signal S1 in the acid gas concentration signal S0, and a sulfur oxide gas calculation unit 62b that receives the sulfur oxide gas concentration signal S2. Is provided.

  As will be described later, the hydrogen chloride gas calculation unit 62a calculates the hydrogen chloride side addition amount AgS1 (kg / h), which is the addition amount (kg / h) per unit time, based on the hydrogen chloride gas concentration signal S1. The hydrogen chloride addition amount signal S3 is output.

  As will be described later, the sulfur oxide gas calculation unit 62b is based on the sulfur oxide gas concentration signal S2, and the sulfur oxide side addition amount AgS2 (kg / h), which is the addition amount per unit time (kg / h). Is calculated and output as a sulfur oxide addition amount signal S4.

The basic addition amount calculation unit 63 calculates the basic addition amount Fa (kg / h) based on the first addition amount (kg / h) of the first addition amount signal S21, and calculates the calculated basic addition amount Fa (kg / h). h) is output as the basic addition amount signal S5.
The basic addition amount Fa (kg / h) is an average addition amount (kg / h) of the first addition amount (kg / h) per predetermined time such as 10 minutes, for example.

  Based on the hydrogen chloride addition signal S3, the sulfur oxide addition signal S4, and the basic addition signal S5, the normal addition amount calculation unit 64 calculates the normal addition amount AgSQ that is the addition amount (kg / h) per unit time. Calculate and output as a normal addition amount signal S6.

  Generally, PID control is often used for the addition amount control device. In PID control, only a single upper limit output value and lower limit output value can be set. Therefore, for example, in general PID control, when the control target value (ppm) of the hydrogen chloride gas concentration in the discharge path is set to 40 ppm, when the hydrogen chloride gas concentration is equal to or lower than the control target value, the PID control is A signal is output to add at the lower limit addition amount (kg / h) which is the lower limit of the output, and when the hydrogen chloride gas concentration is equal to or higher than the control target value, the upper limit addition amount (kg / h) which is the upper limit of the control output ) Output a signal to add. At this time, when a state in which the hydrogen chloride gas concentration repeatedly increases or decreases in a short time occurs, the general PID control performs an output value between the lower limit addition amount and the upper limit addition amount in a short time. Repeated output causes inadequate addition (excessive addition, insufficient addition) of alkaline agent. In such a case, the hydrogen chloride gas concentration in the discharge path varies greatly and causes excessive addition of the alkaline agent in the introduction path.

  Therefore, the normal addition amount calculation unit 64 is related to the hydrogen chloride gas concentration and the sulfur oxide gas concentration in the introduction path 3 that cannot be taken into account by the conventional feedback control (PID control), and is a past average as a reasonable value. By calculating the first addition amount (kg / h) on the basis of the basic addition amount Fa (kg / h) indicating the addition amount, the addition amount control device 50 allows the first alkaline agent to be added poorly (excessive addition, shortage). Hunting of the oxidizing gas concentration caused by the addition) can be suppressed, and an appropriate amount of the first alkaline agent can be stably added.

  The emergency determination unit 65 determines whether or not the average concentration (ppm) calculated based on the hydrogen chloride gas concentration signal S1 exceeds a predefined emergency average hydrogen chloride gas concentration (ppm), or sulfur. It is determined whether or not the average concentration (ppm) calculated based on the oxide gas concentration signal S2 exceeds a predefined emergency average sulfur oxide concentration (ppm), and an emergency determination signal S7 indicating emergency or steady state. Is output.

Generally, a combustion exhaust gas treatment facility manages the exhaust gas after treatment, which is discharged, with an average concentration (ppm) of one hour of hydrogen chloride gas concentration (ppm) or sulfur oxide gas concentration (ppm).
On the other hand, the flue gas treatment facility 10 adds an amount (kg / kg) of adding an alkaline agent to the flue gas before being treated by the dust collector based on the concentration (ppm) of the flue gas after treatment treated by the dust collector. h) feedback control for controlling. In this feedback control, the control target value (ppm) is generally set for the instantaneous value of the hydrogen chloride gas concentration (ppm) or the sulfur oxide gas concentration (ppm). While the final target value is being controlled to reach the final target value, the hydrogen chloride gas concentration (ppm) or the sulfur oxide gas concentration (ppm) may exceed the control target value (ppm).
In particular, since the reduction of the addition amount (kg / h) of the alkali agent and the stabilization treatment of hydrogen chloride gas or sulfur oxide gas are contradictory ideas, if the addition amount (kg / h) of the alkali agent is reduced, 1 There is a high possibility that the time average concentration (ppm) will exceed the determined control concentration (ppm).

  Therefore, the emergency judgment unit 65 calculates the emergency average hydrogen chloride gas concentration (ppm), which is calculated based on the hydrogen chloride gas concentration signal S1, for example, the average concentration (ppm) of the hydrogen chloride gas concentration in one hour. For example, the emergency average sulfur oxide that is determined based on the sulfur oxide gas concentration signal S2 is determined, for example, the average concentration (ppm) of the sulfur oxide gas concentration in one hour is determined in advance. It is determined whether or not the concentration (ppm) has been exceeded. If at least one of the concentrations is determined to be exceeded, an emergency determination signal S7 indicating an emergency is output. Otherwise, an emergency determination indicating a steady state is output. The signal S7 is output, and the temporary addition amount calculation unit 66 is made to select an appropriate addition amount.

The temporary addition amount calculation unit 66 outputs the temporary first addition amount signal S8 based on the normal addition amount signal S6 when receiving the emergency determination signal S7 indicating the steady state, and the emergency determination signal S7 indicating the emergency. Is received, a predetermined emergency addition amount (kg / h) larger than the normal addition amount (kg / h) is output as the provisional first addition amount signal S8.
That is, when the average value of the acid gas concentration (ppm) exceeds the predefined emergency addition concentration (ppm), the provisional addition amount calculation unit 66 is defined in advance instead of the normal addition amount (kg / h). A first addition amount that adds an urgent addition amount (kg / h) is calculated. For this reason, when feedback control is performed on the addition amount (kg / h) of the alkaline agent, if the one-hour average value (ppm) reaches or exceeds the control concentration (ppm), the provisional addition amount Since the calculation unit 66 calculates the emergency addition amount (kg / h) larger than the normal addition amount (kg / h) based on the emergency determination signal S7 from the emergency determination unit 65, the addition amount can be reduced and the acidity can be reduced. Highly reliable control that can achieve both stable gas treatment is possible.

The device addition amount limiting unit 67 calculates the first addition amount (kg / h) based on the temporary first addition amount signal S8. Specifically, when the provisional first addition amount (kg / h) exceeds the maximum addition amount LHS (kg / h) of the first addition device 42, the device addition amount restriction unit 67 determines the maximum addition amount LHS. The first addition amount signal S21 is output with (kg / h) as the first addition amount (kg / h). In addition, when the provisional first addition amount (kg / h) is lower than the minimum addition amount LOS (kg / h) of the first addition device 42, the device addition amount limiting unit 67 determines the minimum addition amount LOS (kg / h). The first addition amount signal S21 is output with h) as the first addition amount (kg / h).
Thus, the device addition amount limiting unit 67 is always between the maximum addition amount LHS (kg / h) and the minimum addition amount LOS (kg / h) so as to be equal to or less than the control target value SV (ppm). In order to add the first addition amount (kg / h) of the first alkaline agent, the first addition amount signal S21 is output.

  The second addition amount calculating unit 70 outputs an average first addition amount calculating unit 71, an average second addition amount calculating unit 72, a target addition amount defining unit 73, and a second addition amount signal S22. A basic calculation unit 74.

  The average first addition amount calculation unit 71 receives the first addition amount signal S21 and, for example, an average first addition amount AgSQA that is an average value of the first addition amount (kg / h) in a predetermined time such as 10 minutes. (Kg / h) is calculated, and the calculated average first addition amount AgSQA (kg / h) is output as the average first addition amount signal S11.

  Based on the second addition amount signal S22, the average second addition amount calculation unit 72, for example, an average second addition amount (average value of the second addition amount (kg / h) in a predetermined time such as 10 minutes ( kg / h) is calculated, and the calculated average second addition amount AgCQA (kg / h) is output as the average second addition amount signal S12.

  The target addition amount defining unit 73 outputs a predetermined target addition amount AgSQT (kg / h) as a target addition amount signal S13.

  The second addition amount basic calculation unit 74 calculates the second addition amount AgCQ (kg / h) based on the average first addition amount signal S11, the average second addition amount signal S12, and the target addition amount signal S13. 2 is output as an addition amount signal S22.

  The first addition device 42 adds the first addition amount (kg / h) of the first alkaline agent to the treated exhaust gas based on the first addition amount signal S21. Similarly, the second addition device 44 adds the second addition amount (kg / h) of the second alkaline agent to the processed combustion exhaust gas based on the second addition amount signal S22.

The fly ash accumulator 19 collects fly ash removed from the combustion exhaust gas by the dust collector 18. The fly ash accumulator 19 stabilizes the fly ash by adding at least one selected from an iron-based compound, a phosphoric acid-containing compound, and a neutralizer to the collected fly ash.
Specifically, heavy metals contained in fly ash are generally fixed and insolubilized by addition of a chelate such as diethyldithiocarbamate. However, although the fixing effect of chelates of heavy metals is high in the short term, heavy metals such as lead re-elute from the immobilized heavy metals due to the pH drop due to acid rain and the oxidative autolysis of the chelates at the final disposal site. There is a fear.
Therefore, by adding a phosphoric acid compound such as phosphoric acid to heavy metals, the added heavy metals can be changed to the form of hydroxyapatite, which is an inorganic mineral, so that the long-term stability at the final disposal site is excellent. For this reason, the stabilization process which adds phosphoric acid compounds, such as phosphoric acid, to a heavy metal is a very high-value processing method from a viewpoint of environmental protection. Furthermore, the method of treating fly ash treated with fine powdered sodium bicarbonate with a heavy metal fixing agent such as phosphoric acid is an effective means having many environmental load reducing effects.

  The heavy metal fixing agent for fixing heavy metals contained in fly ash is not particularly limited as long as it can be applied to fly ash and can obtain the effect of fixing heavy metals. As the heavy metal fixing agent, an organic chelating agent is generally used. Examples of the organic chelating agent include piperazine dithiocarbamate, diethyldithiocarbamate, dimethyldithiocarbamate, and dibutyldithiocarbamate.

  Further, from the viewpoint of long-term immobilization of heavy metals at a disposal site, heavy metal immobilization with a phosphoric acid compound that forms chloropyromorphite and immobilizes in the form of minerals is an effective means. As the phosphoric acid compound, phosphoric acid or phosphate may be a water-soluble phosphoric acid compound, and the shape may be a powder or an aqueous solution. For example, orthophosphoric acid (orthophosphoric acid), polyphosphoric acid, metalin Acid, hypophosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, superphosphoric acid, primary sodium phosphate, secondary sodium phosphate, tertiary sodium phosphate, primary potassium phosphate, secondary phosphoric acid Potassium, tribasic potassium phosphate, primary calcium phosphate, dibasic calcium phosphate, primary magnesium phosphate, secondary magnesium phosphate, primary ammonium phosphate, secondary ammonium phosphate, lime superphosphate, sodium tripolyphosphate, tripolyphosphoric acid Potassium, sodium hexametaphosphate, potassium hexametaphosphate, sodium pyrophosphate, potassium pyrophosphate, sodium phosphite, phosphorus Potassium, sodium hypophosphite, potassium hypophosphite, and the like. In particular, orthophosphoric acid, primary phosphate, secondary phosphate, tertiary phosphate, tripolyphosphate, hexametaphosphate, and pyrophosphate exhibit a good heavy metal fixing effect. Moreover, since orthophosphoric acid having a high acidity is likely to corrode the pipe, it is preferable to apply an aqueous solution of phosphate or an alkali agent such as sodium hydroxide to adjust the pH to 3 or more.

  In addition to these agents, it is preferable to add an iron-based compound so that hexavalent chromium, arsenic, selenium, mercury and the like are not eluted from heavy metals. Examples of the iron-based compound include ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, polyiron sulfate, and iron powder, and ferrous chloride is most preferable.

Further, when a large amount of alkali residue is contained in the fly ash, it is preferable to use an inexpensive neutralizing agent such as aluminum chloride, polyaluminum chloride, hydrochloric acid, or sulfuric acid band together with the alkali agent.
When the fly ash is solidified, cements such as calcined gypsum, Portland cement, early-strength cement, jet cement, blast furnace cement, and alumina cement may be added.
In particular, when applying heavy metal treatment by applying at least one of iron-based compounds, phosphate compounds, and neutralizing agents to heavy metals in fly ash, unreacted alkali residues are added to these heavy metal fixing agents. Increase the amount. In contrast, by applying the stabilization method according to the present invention, the amount of alkali agent added can be optimized, the amount of unreacted alkali residue can be reduced, and the amount of fly ash heavy metal fixing agent added can be reduced. , Environmental load can be reduced.

  In addition, as a means for prescribing the addition amount of the above-mentioned neutralizing agent and the acidic agent such as phosphoric acid of fly ash, the alkali residue in fly ash is measured, and the addition amount is determined according to the value of the measured alkali residue. It is preferable to adjust. Thereby, acidic agents, such as a neutralizing agent and phosphoric acid, can be added without excess and deficiency, and the appropriate utilization of chemicals and a stable treatment can be realized.

  As shown in FIG. 2, the hydrogen chloride gas calculating unit 62a includes an addition amount correspondence defining unit 625a in which basic addition amount correspondence information (see FIGS. 4 and 5) for hydrogen chloride gas is defined, and a concentration amount calculation. Unit 622a, basic addition amount calculation unit 623a, increase correction value defining unit 621a, decrease correction value defining unit 624a, and addition amount calculating unit 626a.

The addition amount correspondence defining unit 625a defines basic addition amount correspondence information that defines the addition amount of the first alkaline agent to be added to the instantaneous hydrogen chloride gas concentration PV.
The basic addition amount correspondence information includes an acid gas concentration and an upper limit (maximum addition amount LHS (kg / h) corresponding to the lower limit (minimum addition amount LOS (kg / h)) of the addition amount control device 50. )), The amount of addition is limited so that an output exceeding a certain control output value does not occur within a certain hydrogen chloride gas concentration range.

  In general PID control, there is only one control output upper limit value. For example, when the control target value is 40 ppm, for example, when the acid gas concentration exceeds the control target value, regardless of the acid gas concentration in the introduction path, The first alkaline agent is added up to the control output upper limit value, thereby causing excessive addition.

  On the other hand, the addition amount correspondence defining unit 625a is able to limit the control output in accordance with the current acid gas concentration, that is, in accordance with the acid gas concentration in the introduction path 3, an appropriate amount of the first alkaline agent. The basic addition amount correspondence information is defined so that the addition amount of the first alkaline agent can be reduced.

  For example, as shown in FIG. 4 and FIG. 5, the basic addition amount correspondence information specifically includes the addition amount SQ (kg / h) to be added to the instantaneous hydrogen chloride gas concentration PV of the hydrogen chloride gas concentration signal S1. ) Is indicated by an addition amount correspondence information line L including a line connecting 0-point a-point b, a line connecting point c-point d, and a line after point e.

The addition amount correspondence information line L is specifically as follows. When the instantaneous hydrogen chloride gas concentration PV (ppm) ranges from 0 ppm to less than the control target value (also referred to as control output start concentration) SV (ppm) (range from 0 to point a), the addition amount SQ (kg / h) ) Is defined as 0.
Range (points) where the instantaneous hydrogen chloride gas concentration PV (ppm) is not less than the control target value SV (ppm) and less than the first output limit corresponding concentration SM1 (ppm) corresponding to the first output limit addition amount LM1 (kg / h) In the range from a to point b), the addition amount SQ (kg / h) is defined based on the following equation.

Addition amount SQ = (first output limit addition amount LM1) × (instantaneous hydrogen chloride gas concentration PV−control target value SV) / (first output limit corresponding concentration SM1−control target value SV)

The instantaneous hydrogen chloride gas concentration PV (ppm) is equal to or higher than the first output limit corresponding concentration SM1 (ppm) corresponding to the first output limit addition amount LM1 (kg / h), and the second output limit addition amount LM2 (kg / h) In the range less than the second output limit corresponding concentration SM2 (ppm) corresponding to the range (the range from the point c to the point d), the addition amount SQ (kg / h) is defined as the second output limit addition amount LM2 (kg / h). Is done.
When the instantaneous hydrogen chloride gas concentration PV (ppm) is equal to or higher than the second output limit corresponding concentration SM2 (ppm) corresponding to the second output limit addition amount LM2 (kg / h) (range after the point e), the addition amount SQ ( kg / h) is defined as the output upper limit addition amount LM3. The second output limit addition amount LM2 and the output upper limit addition amount LM3 are both corresponding addition amount upper limit values.

  As shown in FIG. 2, the concentration amount calculation unit 622a can determine whether the instantaneous hydrogen chloride gas concentration (ppm) is increasing or decreasing based on the hydrogen chloride gas concentration signal S1. A hydrogen chloride gas concentration amount θ representing a rate of increase / decrease in concentration (ppm) (slope of change in instantaneous hydrogen chloride gas concentration) is calculated.

  The basic addition amount calculation unit 623a is similar to the basic addition amount calculation unit 63, for example, based on the average addition amount of the first addition amount (kg / h) at a predetermined time such as 10 minutes, the basic addition amount Fa (kg / H).

  When the value of the hydrogen chloride gas concentration amount θ is positive, that is, when the hydrogen chloride gas concentration is increasing, the increase correction value defining unit 621a is the basic increase correction that corrects the basic addition amount correspondence information. The value SVA (ppm) is specified.

  When the value of the hydrogen chloride gas concentration θ does not change or is negative, that is, when the hydrogen chloride gas concentration is stable or is in a descending state, the downward correction value defining unit 624a displays the basic addition amount correspondence information. A descent correction coefficient LMG (unit is dimensionless) that is a basis for correction is defined. The descent correction coefficient LMG is set to a value less than 1.

  The addition amount calculation unit 626a corrects the basic addition amount correspondence information based on the acid gas concentration amount θ, the basic addition amount Fa, the increase correction value SVA, and the decrease correction coefficient LMG, and outputs a hydrogen chloride addition amount signal S3.

  As shown in FIG. 3, the sulfur oxide gas calculation unit 62b is also provided with basic addition amount correspondence information (similar to FIG. 4 and FIG. 5) for sulfur compounds, like the hydrogen chloride gas calculation unit 62a. An amount correspondence defining unit 625b, a concentration amount calculating unit 622b, a basic addition amount calculating unit 623b, an increase correction value defining unit 621b, a decrease correction value defining unit 624b, and an addition amount calculating unit 626b are provided.

  The addition amount correspondence defining part 625b defines basic addition amount correspondence information that defines the addition amount of the first alkaline agent to be added to the sulfur oxide gas concentration. The relationship of the addition amount SQ (kg / h) to be added to the instantaneous sulfur oxide gas concentration PV of the sulfur oxide gas concentration signal S2 which is basic addition amount correspondence information is shown in FIG. 4 and FIG. The relationship is the same as that of the information line L.

  As shown in FIG. 3, the concentration amount calculation unit 622b is configured to increase or decrease the instantaneous sulfur oxide gas concentration (ppm) based on the sulfur oxide gas concentration signal S2 (inclination of change in instantaneous sulfur oxide gas concentration). Is calculated to determine whether the instantaneous sulfur oxide gas concentration (ppm) is rising or falling.

Similar to the basic addition amount calculation unit 63, the basic addition amount calculation unit 623b calculates the basic addition amount Fa based on the average addition amount of the first addition amount (kg / h) at a predetermined time such as 10 minutes, for example. To do.
The increase correction value defining unit 621b is a basic increase correction value for correcting the basic addition amount correspondence information when the value of the sulfur oxide gas concentration amount θ is positive, that is, when the sulfur oxide gas concentration is increasing. SVA (ppm) is specified.
The downward correction value defining unit 624b corrects the basic addition amount correspondence information when the value of the sulfur oxide gas concentration amount θ does not change or is negative, that is, when the sulfur oxide gas concentration is stable or decreasing. A basic descent correction coefficient LMG (unit is dimensionless) is defined. The descent correction coefficient LMG is set to a value less than 1.

  The addition amount calculation unit 626b corrects the basic addition amount correspondence information based on the sulfur oxide gas concentration amount θ, the basic addition amount Fa, the increase correction value SVA, and the decrease correction coefficient LMG, and generates a sulfur oxide addition amount signal S4. Output.

An acid gas stabilization method performed by the combustion exhaust gas treatment facility 10 will be described.
First, while the combustion exhaust gas treatment facility 10 is in operation, an acid gas concentration measurement step is performed in which the combustion exhaust gas is treated by the dust collector 18 and the acid gas concentration in the treated combustion exhaust gas flowing through the introduction path 3 is measured.
Specifically, the hydrogen chloride gas concentration measuring device 32 performs a hydrogen chloride gas concentration measuring step for measuring an instantaneous hydrogen chloride gas concentration which is a real-time hydrogen chloride gas concentration in the acid gas, and the measured instantaneous hydrogen chloride gas is measured. The concentration is output as a hydrogen chloride gas concentration signal S1. Similarly, the sulfur oxide gas concentration measuring device 34 performs a sulfur oxide concentration measuring step of measuring an instantaneous sulfur oxide gas concentration which is a real-time sulfur oxide gas concentration in the acid gas, and the measured instantaneous sulfur oxidation. The product gas concentration is output as the sulfur oxide gas concentration signal S2.

As shown in FIGS. 6 and 7, the hydrogen chloride gas calculation unit 62a adds the hydrogen chloride side addition that is the addition amount (kg / h) of the first additive per unit time based on the hydrogen chloride gas concentration signal S1. An amount AgS1 (kg / h) is calculated and output as a hydrogen chloride addition amount signal S3.
As shown in FIG. 6, the basic addition amount calculation unit 623a calculates the basic addition amount Fa based on the average addition amount of the first addition amount (kg / h) at a predetermined time such as 10 minutes, for example ( Step ST01). The basic addition amount Fa calculated here is a value serving as a basis for lowering the addition amount SQ (kg / h), and is used in steps ST11 and ST15.

  Next, the addition amount calculation unit 626a increases the instantaneous hydrogen chloride gas concentration (ppm) based on the instantaneous hydrogen chloride gas concentration (ppm) calculated by the concentration amount calculation unit 622a based on the hydrogen chloride gas concentration signal S1. It is determined whether it is in a rising state, or is in a constant state or is in a decreasing state (step ST03). If it is determined that the addition amount calculation unit 626a is in the rising state, the process proceeds to step ST04. If it is determined that the addition amount calculation unit 626a is in the falling state, the process proceeds to step ST18.

As shown in FIG. 4, the addition amount calculation unit 626a determines that the addition amount correspondence information line L is in the rising state in step ST03, so that the addition amount correspondence information line L is corrected to the addition amount correspondence information line L2 via the addition amount correspondence information line L1. (Step ST04).
Specifically, the addition amount calculation unit 626a first adds an addition amount correspondence information line L (a line connecting 0-point a-point b, a line connecting point c-point d, a line after point e). The value of the instantaneous hydrogen chloride gas concentration PV is subtracted by the increase correction value SVA, and the addition amount correspondence information line L1 (a line connecting 0-point a1-point b1, a line connecting point c1-point d1, and after point e1) ).
The addition amount calculation unit 626a then adds the addition amount correspondence information line L2 (the line connecting 0-point a1 to point b2) obtained by reducing the value of the addition amount SQ obtained by the addition amount correspondence information line L1 by the basic addition amount Fa. , A line connecting point c2 to point d2, a line after point e2).
As shown in FIG. 6, next, the addition amount calculation unit 626a calculates the addition amount SQ (kg / h) to be added according to the instantaneous hydrogen chloride gas concentration PV, based on the addition amount correspondence information line L2. (Steps ST05 to ST17).

  First, when the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is in a range from 0 to (control target value SV (ppm) −increase correction value SVA (ppm)) (step ST05), the addition Based on the amount correspondence information line L2, the addition amount SQ (kg / h) is calculated as 0 (step ST07).

Further, the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is from (control target value SV (ppm) −increase correction value SVA (ppm)) to (first output restriction corresponding concentration SM1 (ppm) −increase correction value). If it is determined that it is in the range up to SVA (ppm) (step ST09), the addition amount SQ (kg / h) is calculated based on the addition amount correspondence information line L2 (step ST11).
Specifically, from (control target value SV (ppm) −increase correction value SVA (ppm)) of the addition amount correspondence information line L2, (first output restriction corresponding concentration SM1 (ppm) −increase correction value SVA (ppm)) The addition amount SQ (kg / h) in the range up to is calculated based on the following equation.

Addition amount SQ = (first output limit addition amount LM1−basic addition amount Fa) × (instantaneous hydrogen chloride gas concentration PV− (control target value SV−increase correction value SVA)) / (first output limit corresponding concentration SM1−control) Target value SV)

  Further, the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is from (first output restriction corresponding concentration SM1 (ppm) −increased correction value SVA (ppm)) to (second output restriction corresponding concentration SM2 (ppm) −). If it is determined that the value is within the range up to the correction value SVA (ppm) (step ST13), the addition amount SQ (kg / h) is calculated based on the addition amount correspondence information line L2 (step ST15). Here, from (first output restriction corresponding concentration SM1 (ppm) −increase correction value SVA (ppm)) of the addition amount correspondence information line L2, (second output restriction corresponding concentration SM2 (ppm) −increase correction value SVA (ppm)) The addition amount SQ (kg / h) in the range up to is calculated based on the following equation.

Addition amount SQ = second output limit addition amount LM2-basic addition amount Fa

  If the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV exceeds (second output limit corresponding concentration SM2 (ppm) −increase correction value SVA (ppm)) (step ST13), the addition amount correspondence Based on the information line L2, the addition amount SQ (kg / h) is calculated (step ST17). Here, the addition amount SQ (kg / h) in the range exceeding the (second output limit corresponding concentration SM2 (ppm) −the increase correction value SVA (ppm)) of the addition amount correspondence information line L2 is based on the following equation: Calculated.

Addition amount SQ = Output upper limit addition amount LM3-Basic addition amount Fa

  As shown in FIG. 7, next, the addition amount calculation unit 626a determines that it is in the descending state in step ST03, so that the addition amount corresponding to the instantaneous hydrogen chloride gas concentration PV is added based on the addition amount correspondence information line L. A power addition amount SQ (kg / h) is calculated (steps ST19 to ST33).

  As shown in FIG. 5, the addition amount calculation unit 626a determines that the addition amount correspondence information line L is in the descending state in step ST03, so that the addition amount correspondence information line L is corrected to the addition amount correspondence information line L4 via the addition amount correspondence information line L3. (Step ST18).

  Specifically, the addition amount calculation unit 626a first adds an addition amount correspondence information line L (a line connecting 0-point a-point b, a line connecting point c-point d, a line after point e). The instantaneous hydrogen chloride gas concentration PV is decreased by the basic addition amount Fa, and the addition amount correspondence information line L3 (a line connecting 0-point a-point b3, a line connecting point c3-point d3, and after point e3 Line).

  As shown in FIG. 7, the addition amount calculation unit 626a first calculates the addition amount SQ (kg / h) to be added according to the instantaneous hydrogen chloride gas concentration PV based on the addition amount correspondence information line L3 ( Steps ST19 to ST31). The addition amount correspondence information line L4 in FIG. 5 is a line obtained by reducing the addition amount correspondence information line L3 by the ratio of the drop correction coefficient LMG, and a line connecting between the point 0 and the point b4 and between the point c4 and the point d4. A connecting line, a line after point e4.

  First, when the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is in a range from 0 to (control target value SV (ppm)) (step ST19), based on the addition amount correspondence information line L4. The addition amount SQ1 (kg / h) is calculated as 0 (step ST21).

In addition, when the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is in the range from (control target value SV (ppm)) to (first output restriction corresponding concentration SM1 (ppm)) (step ST23). ), The addition amount SQ1 (kg / h) is calculated based on the addition amount correspondence information line L3 (step ST25).
Specifically, the addition amount SQ1 (kg / h) in the range from (control target value SV (ppm)) to (first output restriction corresponding concentration SM1 (ppm)) of the addition amount correspondence information line L3 is as follows. Calculated based on the formula.

Addition amount SQ1 = (first output limit addition amount LM1 × drop correction coefficient LMG−basic addition amount Fa) × (instantaneous hydrogen chloride gas concentration PV−control target value SV) / (first output limit corresponding concentration SM1−control target value) SV)

  Further, when the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV is in a range from (first output restriction corresponding concentration SM1 (ppm)) to (second output restriction corresponding concentration SM2 (ppm)). (Step ST27) Based on the addition amount correspondence information line L3, the addition amount SQ1 (kg / h) is calculated (step ST29). Here, the addition amount SQ1 (kg / h) in the range from (first output restriction correspondence concentration SM1 (ppm)) to (second output restriction correspondence concentration SM2 (ppm)) of the addition amount correspondence information line L3 is as follows. It is calculated based on the following formula.

Addition amount SQ1 = second output limit addition amount LM2 × drop correction coefficient LMG−basic addition amount Fa

  If the addition amount calculation unit 626a determines that the instantaneous hydrogen chloride gas concentration PV exceeds (second output restriction corresponding concentration SM2 (ppm)) (step ST27), the addition amount calculation unit 626a adds based on the addition amount correspondence information line L3. The amount SQ1 (kg / h) is calculated (step ST31). Here, the addition amount SQ1 (kg / h) in the range exceeding the (second output restriction corresponding concentration SM2 (ppm)) of the addition amount correspondence information line L3 is calculated based on the following equation.

Addition amount SQ1 = Output upper limit addition amount LM3 × Descent correction coefficient LMG−Basic addition amount Fa

  Thus, the addition amount calculation unit 626a sets the addition amount SQ (kg / h) as the hydrogen chloride side addition amount AgS1 (kg / h), and the hydrogen chloride addition amount signal S3 indicating the hydrogen chloride side addition amount AgS1 (kg / h). Output as.

  Based on the sulfur oxide gas concentration signal S2, the sulfur oxide gas calculation unit 62b calculates the sulfur oxide side addition amount AgS2 (kg / h), which is the addition amount (kg / h) of the first additive per unit time. Is calculated and output as a sulfur oxide addition amount signal S4. Similarly to the addition amount calculation unit 626a, the addition amount calculation unit 626b that calculates the sulfur oxide side addition amount AgS2 by the sulfur oxide gas calculation unit 62b is also based on the addition amount SQ (kg / kg). h) Calculate and output the calculated addition amount SQ (kg / h) as the sulfur oxide side addition amount AgS2 (kg / h).

  The basic addition amount calculation unit 63 always outputs the basic addition amount Fa (kg / h) as the basic addition amount signal S5 based on the first addition amount (kg / h) of the first addition amount signal S21.

  The normal addition amount calculation unit 64, based on the following formula, adds the hydrogen chloride side addition amount AgS1 of the hydrogen chloride addition amount signal S3, the sulfur oxide side addition amount AgS2 of the sulfur oxide addition amount signal S4, and the basic addition amount signal S5. The normal addition amount AgSQ (kg / h) is calculated based on the basic addition amount Fa (kg / h). At this time, the hydrogen chloride side addition amount AgS1 (kg / h) and the sulfur oxide side addition amount AgS2 (kg / h) are both lower limit (basic addition amount Fa (kg / H)) is subtracted from the basic addition amount Fa so as not to affect the addition amount of the portion exceeding the basic addition amount Fa. Therefore, the normal addition amount AgSQ (kg / h) is equal to the hydrogen chloride side addition amount AgS1 (kg / h) so that the lower limit of the normal addition amount AgSQ (kg / h) is the basic addition amount Fa (kg / h). ) And sulfur oxide side addition amount AgS2 (kg / h), in addition to the lower limit (basic addition amount), the addition amount derived from the hydrogen chloride gas concentration signal S1 and the sulfur oxide gas concentration signal S2 The lower limit is adjusted.

Normal addition amount AgSQ (kg / h) = hydrogen chloride side addition amount AgS1 (kg / h) + sulfur oxide side addition amount AgS2 (kg / h) + basic addition amount Fa (kg / h)

  The emergency determination unit 65 always outputs an emergency determination signal S7 indicating emergency or steady state based on the hydrogen chloride gas concentration signal S1 and the sulfur oxide gas concentration signal S2.

  The temporary addition amount calculation unit 66 outputs the temporary first addition amount signal S8 based on the normal addition amount signal S6 when receiving the emergency determination signal S7 indicating the steady state, and the emergency determination signal S7 indicating the emergency. Is received, the emergency addition amount (kg / h) defined in advance larger than the normal addition amount AgSQ (kg / h) is output as the provisional first addition amount signal S8.

  The device addition amount limiting unit 67 falls within the range of the maximum addition amount LHS (kg / h) of the first addition device 42 and the minimum addition amount LOS (kg / h) based on the temporary first addition amount signal S8. Thus, the first addition amount (kg / h) is calculated.

  The average first addition amount calculation unit 71 outputs the average first addition amount AgSQA (kg / h) calculated based on the first addition amount signal S21 as the average first addition amount signal S11.

  The average second addition amount calculation unit 72 outputs the average second addition amount (kg / h) calculated based on the second addition amount signal S22 as the average second addition amount signal S12.

  The target addition amount defining unit 73 outputs the target addition amount signal S13 indicating the target addition amount AgSQT (kg / h).

  Based on the average first addition signal S11, the average second addition signal S12, and the target addition signal S13, the second addition amount basic calculation unit 74 uses, for example, the following expression to calculate the second addition amount: AgCQ (kg / h) is calculated and output as the second addition amount signal S22.

Second addition amount AgCQ = average first addition amount AgSQA + average second addition amount AgCQA−target addition amount AgSQT

  The first addition device 42 adds the first addition amount of the first alkaline agent to the combustion exhaust gas in the introduction passage 3 based on the first addition amount signal S21, and the second addition device 44 adds the second addition amount. Based on the quantity signal S22, a second addition amount of the second alkaline agent is added to the combustion exhaust gas in the introduction path 3.

  Since the flue gas treatment facility 10 can appropriately control the addition amounts of two different alkali agents, it is possible to prevent excessive addition of the alkali agent while maintaining a stable treatment of acid gas. Moreover, since the addition amount of the alkali agent can be appropriately performed, the amount of unreacted alkali in the fly ash can be reduced, the amount of fly ash generated can be reduced, and the fixing agent that immobilizes heavy metals. Can be reduced, and as a result, the environmental load can be reduced.

  The present invention will be described more specifically with reference to the following examples. The combustion exhaust gas treatment facility 10 according to the present invention can appropriately add the first alkaline agent and the second alkaline agent and stably treat the acidic gas. As described above, the addition amount of the first alkaline agent is controlled on the downstream side of the dust collector 18 based on the hydrogen chloride gas concentration signal S1 and the sulfur oxide gas concentration signal S2, and based on the addition amount of the first alkaline agent. The feedback control is performed to control the amount of the second alkaline agent added, and the present invention is not limited to the examples.

Comparative Example In an industrial waste incinerator where the fluctuation of acid gas is intense, a hydrogen chloride measuring device (manufactured by Kyoto Electronics Industry Co., Ltd.) is introduced into the upstream introduction path 3 (inlet HCl) from the position where the alkali agent addition device is installed. KLA-1) was installed and the hydrogen chloride gas concentration was measured. Further, slaked lime (second alkaline agent, JIS special slaked lime) is added to the upstream side of the dust collector 18 at a fixed amount of 338 kg / h, and fine baking soda (first alkaline agent 2, Kurita Kogyo Co., Ltd., Hypercer B-) The hydrogen chloride gas concentration (outlet HCl) measured by a hydrogen chloride measuring device (KLA-1 manufactured by Kyoto Electronics Industry Co., Ltd.) installed in the discharge channel 4 downstream of the dust collector 18 is output. Emission based on the gas concentration signal S1 and the sulfur oxide gas concentration signal S2 from which the sulfur oxide gas concentration (exit SOx) measured by the sulfur oxide measuring device (manufactured by Fuji Electric Co., Ltd., ZRG) is output Feedback control was performed with an oxygen conversion value for managing the concentration in the passage 4.
At this time, feedback control by fine hydrogen chloride (first alkaline agent) outlet hydrogen chloride (inlet HCl) and sulfur oxide concentration signal was performed with the following settings.

Further, fly ash in this application method was periodically collected, and raw ash INDEX (alkaline residue) serving as an index of the unreacted portion of the alkali agent was measured. Further, a sulfuric acid band and a phosphoric acid aqueous solution were added, and a heavy metal elution test (Environment Agency Notification No. 13 test) was conducted to evaluate the required addition amount.
In this evaluation condition, 1.88 equivalents (338 kg / h) of slaked lime and 0.28 equivalents (115 kg / h) of fine powdered sodium bicarbonate were added, and the outlet hydrogen chloride gas concentration (outlet HCl) was 195 ppm (control target value 200 ppm). The process was equivalent to the control target value, and proper control was possible.
8 and 11 show changes in the inlet hydrogen chloride gas concentration (inlet HCl) and slaked lime addition equivalent.
According to the graph of FIG. 8, the slaked lime addition equivalent tends to decrease as the inlet hydrogen chloride gas concentration (inlet HCl) increases. This is because the slaked lime is excessively sprayed when the inlet hydrogen chloride gas concentration (inlet HCl) is low, and the slaked lime is insufficient when the inlet hydrogen chloride gas concentration (inlet HCl) is lowered. It shows that the amount of alkali agent added increases.
Regarding the heavy metal treatment of fly ash, the average of raw ash INDEX (alkali residue) in the fly ash was 305. Moreover, as a result of adding 3% of 75% phosphoric acid aqueous solution and changing the addition amount of 27% aluminum sulfate aqueous solution and evaluating the required addition amount, the required addition amount of 27% aluminum sulfate aqueous solution was 55% on average.

Second alkaline agent addition conditions Second alkaline agent: slaked lime: 338 (kg / h) fixed addition

First alkaline agent: feedback control of fine powdered baking soda AgSO = AgSQ ÷ LHS × 100
AgSO: Fine powder baking soda addition output (%)
AgSQ: Fine powder baking soda addition amount (normal addition amount) (kg / h)
LHS: Maximum addition amount of fine powder baking soda addition device (maximum addition amount of first addition device): 400 (kg / h)
AgSQ = (AgS1 + AgS2) + Fa
AgS1: Addition amount specified from the output of the outlet HCl measuring device (addition amount on the hydrogen chloride side) (kg / h)
AgS2: Addition amount defined from the output of the outlet SO2 measuring device (addition amount on the sulfur oxide side) (kg / h)
Fa: Fine powder baking soda basic addition amount (basic addition amount) (kg / h)
Fa: Basic addition amount (kg / h): n-minute moving average addition amount (kg / h) × factor (%) ÷ 100
n-minute moving average: 10 (minutes)
Coefficient: 70.0 (%)
Here, when AgSQ exceeded LHS, it was set as LHS.
Moreover, it was set as LOS when AgSQ is below LOS (the minimum addition amount of the fine powder sodium bicarbonate addition device (the minimum addition amount of the first addition device)) (kg / h).
LOS: Minimum addition amount of fine powder baking soda addition device (minimum addition amount of first addition device): 40 (kg / h)
In addition, when the outlet HCl concentration (hydrogen chloride gas concentration) and the outlet SO2 concentration (sulfur oxide gas concentration) exceed a certain concentration, the addition output of the emergency addition amount is defined as the main addition output.

Urgent addition amount Urgent addition [Control by outlet HCl 1 hour average]
HCl emergency addition concentration: 213 (ppm)
HCl urgent addition amount: 260 (kg / h)
Emergency addition [Exit SO2 1 hour average control]
SO2 emergency addition concentration: 200 (ppm)
SO2 emergency addition amount: 260 (kg / h)

  Tables 1 and 2 show the control settings.

Example 1
In the same facility, except for controlling the addition of slaked lime (second alkaline agent, JIS special slaked lime) based on the addition amount of fine powder baking soda (first alkaline agent, manufactured by Kurita Kogyo Co., Ltd., Hypercer B-200). Was performed in the same manner as in the comparative example.
Control of slaked lime (second alkaline agent) and fine powdered sodium bicarbonate (first alkaline agent) was performed with the control settings shown below.

In addition, fly ash in this application method is also collected periodically, and the raw ash INDEX (alkali residue) average, which is an indicator of the unreacted amount of the alkaline agent, is measured as in the comparative example, and a sulfuric acid band and a phosphoric acid aqueous solution are measured. Was used to evaluate the required addition amount.
By controlling the amount of slaked lime added with the amount of fine powdered baking soda according to the following equation, the outlet hydrogen chloride gas was added by adding 1.74 equivalents (295 kg / h) of slaked lime and 0.28 equivalents (106 kg / h) of finely powdered sodium bicarbonate. The concentration (outlet HCl) could be appropriately controlled as with 195 ppm (control target value 200 ppm). Moreover, the required addition amount of slaked lime was able to be reduced compared with the comparative example by controlling slaked lime by this invention.

9 and 12 show the transition of the inlet hydrogen chloride gas concentration (inlet HCl) and the slaked lime addition equivalent, but when the inlet hydrogen chloride gas concentration increases, the variation of the addition equivalent is slight and the addition equivalent decreases. The trend decreased.
Regarding the heavy metal treatment of fly ash, the average of the raw ash INDEX (alkali residue) in the fly ash was 260, which was lower than that of the comparative example. Moreover, the variation of the addition equivalent was also slight, and the range of fluctuation was 230-290.
Similarly, 3% of 75% phosphoric acid aqueous solution was added, and the addition amount of 27% aluminum sulfate aqueous solution was changed and the necessary addition amount was evaluated. As a result, the required addition amount of 27% aluminum sulfate aqueous solution was 45% on average and heavy metal The amount of fixative added could be reduced.

Feedback control of the second alkaline agent (JIS special slaked lime applied) AgCO = AgCQ ÷ LHC × 100
AgCO: Slaked lime addition output (%)
AgCQ: Slaked lime addition amount (kg / h)

AgCQ = AgCQAve + AgSQAve-AgSQT
AgCQAve: n-minute moving average addition amount of the second alkaline agent slaked lime (kg / h)
AgSQAve: n-minute moving average addition amount (kg / h) of the first alkaline agent fine powder baking soda
AgSQT: Target addition amount (kg / h) of 1st alkaline agent fine powder baking soda
Here, when AgCQ exceeded LMHC, it was set as LMHC.
Moreover, when AgCQ was below LMOC, it was set as LMOC.
The moving average for n is set as follows.
Control LOC of the second alkaline agent (slaked lime): Minimum addition amount of slaked lime equipment: 45 (kg / h)
LHC: Slaked lime equipment maximum addition amount (kg / h): 450 (kg / h)
LMOC slaked lime control minimum addition amount: 200 (kg / h)
LMHC slaked lime control maximum addition amount: 360 (kg / h)
Slaked lime: AgCQAve n-minute moving average time: 10 minutes Fine powder baking soda: AgSQAve n-minute moving average time: 30 minutes Also, the target addition amount of fine powdered sodium bicarbonate is set as follows.
Target amount of fine baking soda: 105 (kg / h)
Further, the control of the first alkaline agent (fine powder baking soda) was set to the same setting as in Comparative Example 1.

Example 2
In the same facility, except for controlling the addition of slaked lime (second alkaline agent, JIS special slaked lime) based on the addition amount of fine powder baking soda (first alkaline agent, manufactured by Kurita Kogyo Co., Ltd., Hypercer B-200). Was performed in the same manner as in the comparative example.
At this time, the control of slaked lime (second alkaline agent) and fine powdered sodium bicarbonate (first alkaline agent) was performed with the following control settings.

AgCQ = AgCQ1Ave
AgCQ1Ave: n-minute moving average addition amount of AgCQ1 (kg / h)
AgCQ1 = A × AgSQ + B
AgSQ: Alkaline agent 2 Addition amount of fine powdered baking soda (kg / h)
AgCQ1 coefficient A: 1.5
AgCQ1 section B: 100
Here, when AgCQ exceeded LMHC, it was set as LMHC.
Moreover, when AgCQ was below LMOC, it was set as LMOC.
LOC: Slaked lime equipment minimum addition amount: 45 (kg / h)
LHC: Slaked lime equipment maximum addition amount: 450 (kg / h)
LMOC: Slaked lime Controlled minimum addition amount: 45 (kg / h)
LMHC: Slaked lime Controlled maximum addition amount: 405 (kg / h)
The moving average for n is set as follows.
AgCQ1: Ave n-minute moving average time: 30 (minutes)

  In addition, fly ash in this application method is also collected periodically, and the raw ash INDEX (alkali residue) average, which is an indicator of the unreacted amount of the alkaline agent, is measured as in the comparative example. Was used to evaluate the required addition amount.

By controlling the addition amount of slaked lime with the addition amount of fine powdered sodium bicarbonate by the following formula, 1.65 equivalents (268 kg / h) of slaked lime and 0.29 equivalents of fine powdered sodium bicarbonate (109 kg / h) were added to the outlet hydrogen chloride gas. The concentration (outlet HCl) could be appropriately controlled in the same manner as 199 ppm (control target value 200 ppm).
Moreover, the required addition amount of slaked lime was able to be reduced significantly compared with the comparative example by controlling slaked lime by this invention.

FIGS. 10 and 13 show the transition of the inlet hydrogen chloride concentration (inlet HCl) and the slaked lime addition equivalent, but this control allows the addition of slaked lime with a stable equivalent regardless of the fluctuation of the inlet hydrogen chloride concentration (inlet HCl). This control is possible and has excellent controllability.
In addition, regarding the heavy metal treatment of fly ash, the average of raw ash INDEX (alkali residue) in fly ash is 230, which is lower than the comparative example and has less fluctuation due to improved controllability. It can be said that the fly ash properties are easy to treat with drugs.
Similarly, 3% of 75% phosphoric acid aqueous solution was added, and the addition amount of 27% aluminum sulfate aqueous solution was changed and the required addition amount was evaluated. As a result, the required addition amount of 27% aluminum sulfate aqueous solution was 40% on average and heavy metal The amount of fixative added could also be reduced.

The results of acid gas treatment are shown in Table 3, and the results of heavy metal treatment are shown in Table 4.

AgCQ Second addition amount AgCQA Average second addition amount AgS1 Hydrogen chloride side addition amount AgS2 Sulfur oxide side addition amount AgSQ First addition amount, normal addition amount AgSQA Average first addition amount AgSQT Target addition amount Fa Basic addition amount L, L1 , L2, L3, L4 Addition amount correspondence information line LHS Maximum addition amount LM1 First output limit addition amount LM2 Second output limit addition amount LM3 Output upper limit addition amount LMG Lowering correction coefficient LOS Minimum addition amount PV Instantaneous hydrogen chloride gas concentration, instantaneous Sulfur oxide gas concentration S0 Acid gas concentration signal S1 Hydrogen chloride gas concentration signal S2 Sulfur oxide gas concentration signal S3 Hydrogen chloride addition amount signal S4 Sulfur oxide addition amount signal S5 Basic addition amount signal S6 Normal addition amount signal S7 Emergency judgment Signal S8 Temporary first addition amount signal S11 Average first addition amount signal S12 Average second addition amount signal S13 Target addition amount signal S 21 First addition amount signal S22 Second addition amount signal SM1 First output restriction corresponding concentration SM2 Second output restriction correspondence concentration SQ, SQ1 Addition amount SV Control target value SVA Increase correction value 2 Pipe 3 Inlet path 4 Exhaust path 10 Combustion exhaust gas Treatment facility 12 Combustion furnace 14 Boiler 16 Temperature reducing tower 18 Dust collector 19 Fly ash accumulator 20 Fan 22 Chimney 30 Acid gas measuring device 32 Hydrogen chloride gas concentration measuring device 34 Sulfur oxide gas concentration measuring device 42 First addition device 44 Second Addition device 50 Addition amount control device 60 First addition amount calculation unit 61 Main addition amount calculation unit 62a Hydrogen chloride gas calculation unit 62b Sulfur oxide gas calculation unit 63 Basic addition amount calculation unit 64 Normal addition amount calculation unit 65 Emergency determination unit 66 Temporary addition amount calculation unit 67 Equipment addition amount restriction unit 70 Second addition amount calculation unit 71 Average first addition amount calculation unit 72 Average second addition amount calculation unit 73 Target addition amount defining unit 74 Second addition amount basic calculating units 621a and 621b Ascending correction value defining units 622a and 622b Concentration amount calculating units 623a and 623b Basic addition amount calculating units 624a and 624b Decreasing correction value defining units 625a and 625b Definition part 626a, 626b addition amount calculation part

Claims (11)

A stable treatment method for stably treating flue gas containing acid gas at a flue gas treatment facility,
An acid gas concentration measuring step for measuring the acid gas concentration in the treated flue gas after treating the flue gas with a dust collector;
Based on the acid gas concentration, acid gas information that is information on the acid gas is calculated, the normal addition amount of the first alkaline agent is calculated based on the acid gas information, and the first addition amount is calculated based on the normal addition amount. A first calculation step of calculating
A second calculation step of calculating a second addition amount of the second alkaline agent based on the first addition amount information regarding the first addition amount;
A first addition step of adding the first addition amount of the first alkaline agent to the treated combustion exhaust gas;
A second addition step of adding the second addition amount of the second alkaline agent to the post-treatment combustion exhaust gas. The first addition amount information includes an average first addition amount of the first addition amount at a predetermined time,
The second calculation step calculates second addition amount information including an average second addition amount of the second addition amount at the predetermined time from the past second addition amount, and calculates the average first addition amount and the average first addition amount. The acid gas stabilization method according to claim 1, wherein the second addition amount is calculated based on two addition amounts and a predetermined target addition amount. The acid gas information includes an acid gas concentration amount representing a rate of change in instantaneous acid gas concentration, which is a real-time acid gas concentration measured in the acid gas concentration measurement step,
The acid gas stabilization method according to claim 1 or 2, wherein the first calculation step corrects the normal addition amount based on a predetermined correction method according to the acid gas concentration amount. In advance, the basic addition amount correspondence information that relates the instantaneous acid gas concentration and the addition amount of the first alkaline agent is defined,
In the first calculation step, when the acid gas concentration amount is in a descending state where the acid gas concentration amount remains constant or decreases, the normal addition amount is based on the instantaneous acid gas concentration and basic decrease addition amount correspondence information. To calculate
Further, when the acid gas concentration amount is increasing, the increase acid amount correspondence information in which the value of the acid gas concentration in the instantaneous acid gas concentration and the basic additive amount correspondence information is reduced by a predetermined correction method. The acid gas stabilization treatment method according to claim 3, wherein the normal addition amount is calculated based on:   In the first calculation step, when the acid gas concentration amount is in a descending state where the state is constant or decreasing, the normal addition amount is corrected to be in a range of more than 0 and less than 1. The acid gas stabilization treatment method according to claim 3 or 4, wherein the acid gas stabilization treatment method is corrected by a value. A plurality of corresponding addition amount upper limit values are provided between the maximum addition amount and the minimum addition amount that can be added in the first addition step,
Each of the plurality of corresponding addition amount upper limit values corresponds to a plurality of acid gas concentrations,
The acid gas information includes an instantaneous acid gas concentration that is an acid gas concentration measured in the acid gas concentration measurement step,
The first calculation step corresponds to a higher concentration of the two adjacent acidic gas concentrations when the instantaneous acidic gas concentration is within a range of two adjacent acidic gas concentrations of the plurality of acidic gas concentrations. The acid gas stable treatment method according to claim 3, wherein the normal addition amount is calculated based on a corresponding addition amount upper limit value. The acid gas information includes an average acid gas concentration that is an average value of the acid gas concentration in a predetermined time,
In the first calculation step, when the average acid gas concentration exceeds a predefined emergency addition concentration, the first addition amount is calculated based on a predefined emergency addition amount instead of the normal addition amount. The acid gas stable treatment method according to any one of claims 1 to 6. The acidic gas includes hydrogen chloride gas and sulfur oxide gas,
The acid gas concentration measurement step includes a hydrogen chloride gas concentration measurement step for measuring a hydrogen chloride gas concentration in the acid gas, and a sulfur oxide concentration measurement step for measuring a sulfur oxide concentration in the acid gas. ,
The acid gas information includes hydrogen chloride information about the hydrogen chloride gas and sulfur oxide information about the sulfur oxide gas,
The first calculating step is based on the hydrogen chloride gas addition amount calculated based on the hydrogen chloride information, the sulfur oxide gas addition amount calculated based on the sulfur oxide information, and the basic addition amount. Calculate the amount added,
The acid gas stabilization method according to any one of claims 1 to 7, wherein the basic addition amount is calculated based on an average addition amount of the first addition amount at a predetermined time. The first alkaline agent is an alkaline agent containing at least 5 to 30 μm of fine baking soda,
The acid gas stabilization method according to any one of claims 1 to 8, wherein the second alkali agent is an alkali agent containing at least slaked lime.   Furthermore, the immobilization process process which adds the at least 1 sort (s) chosen from an iron-type compound, a phosphoric acid containing compound, and a neutralizing agent to the fly ash collected in the said dust collector is described in any one of Claim 1 to 9 The acid gas stable treatment method according to 1. A combustion exhaust gas treatment facility for executing the acid gas stabilization treatment method according to any one of claims 1 to 10,
A dust collector,
An introduction path for introducing the combustion exhaust gas into the dust collector;
A discharge path for discharging the treated exhaust gas after the treatment by the dust collector from the dust collector;
An oxidizing gas measuring device that performs the acid gas concentration measuring step and outputs it as an oxidizing gas information signal;
The first calculation step is executed based on the oxidant gas information signal, and the first addition amount calculation unit that outputs the first addition amount as a first addition amount signal, and the second addition based on the first addition amount signal. An addition amount control device including a second addition amount calculation unit that executes a calculation step and outputs the second addition amount as a second addition amount signal;
A first addition device for performing the first addition step based on the first addition amount signal;
A flue gas treatment facility comprising: a second addition device that executes the second addition step based on the second addition amount signal.