Catalyst flow control method of CO fluid bed reactor

Abstract

A catalyst flow control method for a CO fluid bed reactor comprises the following steps: conveying flue gas to be treated to the CO fluid bed reactor through a flue gas inlet, carrying out CO catalytic oxidation reaction on the flue gas to be treated entering the CO fluid bed reactor under the action of a catalyst, and discharging purified flue gas from which CO is removed from a flue gas outlet; a catalyst in the CO fluid bed reactor is in a free flow state; along the direction from the flue gas inlet to the flue gas outlet, a catalyst in the CO fluidized bed reactor is divided into multiple layers of fluidized beds, and the service time of the catalyst in each layer of fluidized bed is gradually increased layer by layer. According to the invention, the service time of the catalyst in each layer of fluid bed is set to be gradually increased layer by layer, so that the amount of the effective catalyst serving in each layer of fluid bed per unit time is gradually reduced layer by layer to adapt to the CO concentration of the inlet of the corresponding layer of fluid bed, thereby achieving the purpose that the catalyst in each layer of fluid bed is inactivated and discharged after respective different service time; the CO catalyst is efficiently utilized, and the catalyst does not need to be manually replaced after being shut down when being inactivated.

Description

Technical Field

[0001] The present invention relates to a CO reactor, in particular to a method for controlling the flow rate of a catalyst in a CO fluidized bed reactor, and belongs to the technical fields of chemical engineering and environmental protection. Background Art

[0002] Currently, CO catalysts on the market are divided into two categories: precious metal catalysts and non-precious metal catalysts. Precious metal catalysts are less prone to deactivation and have a long lifespan, but they are also very expensive. Non-precious metal catalysts are less expensive but are prone to deactivation, generally occurring after 15-30 days of operation. Deactivation is caused by physical factors (such as wear and tear and dust blockage) and chemical factors (such as sulfur poisoning).

[0003] The existing CO catalyst is honeycomb-shaped, such as Figure 1 As shown, the catalyst is fixedly loaded in the reactor, similar to the catalyst loading in the SCR denitrification reactor, such as Figure 2 As shown in the figure, non-precious metal catalysts are easily deactivated, which requires frequent shutdowns for manual catalyst replacement, affecting the system's operating rate. Manual catalyst replacement is also labor-intensive.

[0004] Furthermore, conventional CO reactors are typically designed based on SCR reactors, with consistent pipe diameters at the reactor inlet and outlet. With this design, CO is continuously consumed and removed during the reaction, resulting in a lower CO concentration near the reactor outlet than at the reactor inlet. This leads to inconsistent catalyst deactivation rates at different locations within the reactor. This means that during the CO removal reaction from flue gas, the catalyst near the reactor inlet may become deactivated, necessitating the complete replacement of the fixed catalyst within the reactor. However, the catalyst near the reactor outlet may not be fully deactivated, requiring replacement without full utilization, resulting in catalyst waste. In this scenario, if the remaining catalyst within the reactor remains in use until it is completely deactivated, the flue gas treatment effect will be severely impacted, resulting in the CO concentration in the flue gas at the reactor outlet failing to meet removal requirements and complying with environmental regulations. This not only increases operating costs but also potentially leads to environmental pollution and legal risks. Therefore, how to improve reactor design and catalyst utilization methods to solve the problems of frequent shutdowns and manual replacements when existing non-precious metal catalysts are deactivated and the need to replace catalysts before they are fully utilized, improve catalyst utilization efficiency, reduce costs, and ensure flue gas treatment effects has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] To address the issues in the prior art where non-precious metal catalysts deactivate, requiring frequent downtime for manual replacement, and catalyst replacement before full utilization, the present invention proposes a CO2 fluidized bed reactor and a method for controlling catalyst flow. The present invention provides a CO2 fluidized bed reactor in which the catalyst freely flows from top to bottom. Fresh CO2 catalyst flows from the top of the reactor, while deactivated CO2 catalyst flows from the bottom, eliminating the need for downtime for manual replacement of the CO2 catalyst. The present invention also divides the CO2 fluidized bed reactor into multiple layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet. The service time of the catalyst in each layer of the fluidized bed increases layer by layer, that is, the flow rate of the catalyst in each layer of the fluidized bed (that is, the discharge or feed rate of the catalyst per unit time) decreases layer by layer, thereby causing the amount of effective catalyst in service in each layer of the fluidized bed per unit time to decrease layer by layer. By changing the amount of catalyst in each layer of the fluidized bed per unit time, the CO concentration (for example, mass concentration) at the inlet of the corresponding layer of the fluidized bed is adapted, thereby achieving the purpose of deactivating and discharging the catalyst in each layer of the fluidized bed after their respective different service times, realizing efficient utilization of the CO catalyst, effectively avoiding the waste of catalyst that occurs when the catalyst is replaced as a whole in a conventional reactor with fixed catalyst loading, and saving costs.

[0006] According to an embodiment of the present invention, a method for controlling the flow rate of catalyst in a CO fluidized bed reactor is provided.

[0007] A method for controlling the flow rate of catalyst in a CO fluidized bed reactor is disclosed. Flue gas to be treated is transported to the CO fluidized bed reactor through a flue gas inlet. The flue gas entering the CO fluidized bed reactor undergoes a CO catalytic oxidation reaction under the action of a catalyst, and the clean flue gas, after removing CO, is discharged through a flue gas outlet. The catalyst within the CO fluidized bed reactor freely flows from top to bottom. The catalyst within the CO fluidized bed reactor is divided into multiple layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet, and the service life of the catalyst within each layer of the fluidized bed increases layer by layer.

[0008] In the present invention, along the direction from the flue gas inlet to the flue gas outlet, the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same.

[0009] Preferably, the catalyst cross-sectional area and catalyst thickness of each layer of the fluidized bed in the CO fluidized bed reactor are the same.

[0010] In the present invention, the catalyst in the CO fluidized bed reactor is in granular or cylindrical form. Preferably, the catalyst has a particle size of 1-20 mm, preferably 3-10 mm.

[0011] In the present invention, the catalyst in the CO fluidized bed reactor is divided into n layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet, wherein n is 2-8, preferably 3-6.

[0012] In the present invention, the flue gas to be treated is flue gas containing CO. Preferably, the flue gas to be treated is flue gas containing CO and O2. Further preferably, the flue gas to be treated is one of sintering flue gas, cement kiln exhaust gas, and blast furnace exhaust gas.

[0013] In the present invention, the method further includes the step of calculating the catalyst flow rate ratio per unit time of each layer of the fluidized bed in the CO fluidized bed reactor, specifically comprising:

[0014] S1. Collecting the working parameters of the flue gas to be treated: detecting the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, the mass concentration of CO in the flue gas to be treated, and the mass concentration of O2 in the flue gas to be treated.

[0015] S2. Based on the operating parameters of the flue gas to be treated, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor.

[0016] S3. Based on the fact that the deactivation rate per unit volume of catalyst discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, the ratio of the service time of the catalysts in each layer of the fluidized bed is calculated, thereby deducing the ratio of the catalyst discharge amount per unit time of each layer of the fluidized bed, that is, the ratio of the catalyst flow amount per unit time of each layer of the fluidized bed is obtained.

[0017] In the present invention, step S1 is specifically as follows:

[0018] Collect the working parameters of the flue gas to be treated: set up a flue gas flow detection device, a CO concentration detection device, and an O2 concentration detection device at the flue gas inlet of the CO fluidized bed reactor. Among them, the flue gas flow detection device detects the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, which is recorded as V, m 3 / h. The CO concentration detection device detects the mass concentration of CO in the flue gas to be treated, which is recorded as C co , mg / m 3 The O2 concentration detection device detects the mass concentration of O2 in the flue gas to be treated, which is recorded as mg / m 3 .

[0019] In the present invention, step S2 is specifically as follows:

[0020] According to the operating parameters of the flue gas to be treated, a catalyst deactivation model is established:

[0021]

[0022] in:

[0023]

[0024] C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3).

[0025]

[0026] Where: Q i A is the deactivation rate of the catalyst per unit volume discharged from the i-th layer of the fluidized bed in the CO fluidized bed reactor, m / h. R is the catalyst activity constant, which is related to the material and specific surface area of the catalyst. The value range of R is 0.2~2. v is the catalyst surface velocity of each layer of fluidized bed, m / h. i is the service time of the catalyst in the i-th layer of fluidized bed, in months. icoin is the CO mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 b1 is the adjustment coefficient, and the value range of b1 is 1 / 2700~1 / 3700. V is the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, m 3 / h. A is the catalyst cross-sectional area of each layer of fluidized bed, m 2 . C (i+1)coin is the CO mass concentration at the inlet of the i+1th layer fluidized bed, mg / m 3 . C icoout is the CO mass concentration at the outlet of the i-th layer fluidized bed, mg / m 3 η i is the CO catalytic oxidation efficiency in the i-th fluidized bed layer. n is the number of fluidized bed layers in the CO fluidized bed reactor. b2 is the correction factor, and the value of b2 ranges from 0.3 to 0.5 m / h. is the O2 mass concentration at the inlet of the i+1 layer fluidized bed, mg / m 3 . M co is the molar mass of CO, g / mol. is the molar mass of O2, g / mol.

[0027] Formulas (1)-(5) are combined to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor:

[0028] Deactivation rate of catalyst per unit volume discharged from the first layer of fluidized bed:

[0029]

[0030] Where: Q1 is the deactivation rate of the catalyst per unit volume discharged from the first layer of fluidized bed, m / h. t1 is the service time of the catalyst in the first layer of fluidized bed, in months. 1coin is the CO mass concentration at the inlet of the first layer of fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the first layer of fluidized bed, mg / m 3 .

[0031] The deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed:

[0032]

[0033] Where: Q2 is the deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed, m / h. t2 is the service time of the catalyst in the second layer of fluidized bed, in months. 2coin is the CO mass concentration at the inlet of the second layer of fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the second layer fluidized bed, mg / m 3 .

[0034] …

[0035] The deactivation rate of the catalyst per unit volume discharged from the nth layer of fluidized bed:

[0036]

[0037] Where: Q n is the deactivation rate of the catalyst per unit volume discharged from the nth layer of fluidized bed, m / h. n is the service time of the catalyst in the nth layer of fluidized bed, in months. ncoin is the CO mass concentration at the inlet of the nth layer fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the nth layer fluidized bed, mg / m 3 .

[0038] In the present invention, step S3 is specifically as follows:

[0039] Based on the fact that the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, we can obtain:

[0040] Q1=Q2=……=Q n …………(9).

[0041] Set the number of fluidized bed layers n in the CO fluidized bed reactor and calculate the ratio of the catalyst service time in each layer of the fluidized bed: t1: t2: ...: tn .

[0042] Since the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same, the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time is calculated as follows:

[0043]

[0044] Where: Z1 is the catalyst discharge of the first layer of fluidized bed per unit time, m 3 / month. Z2 is the catalyst discharge of the second layer of fluidized bed per unit time, m 3 / month. Z n is the catalyst discharge amount per unit time of the nth layer fluidized bed, m 3 / moon.

[0045] The CO2 fluidized bed reactor is equipped with a feed roller (e.g., a motorized roller) at the feed outlet of each fluidized bed layer. The feed rate ratio of the feed rollers of each fluidized bed layer is determined based on the ratio of the catalyst discharge amount per unit time of each fluidized bed layer. Deactivated catalyst in each fluidized bed layer flows out of the feed outlet of the CO2 fluidized bed reactor through the feed rollers at the corresponding feed rate ratio. Simultaneously, fresh catalyst flows into each fluidized bed layer from the feed inlet above the CO2 fluidized bed reactor at the same feed rate ratio. This determines the ratio of the catalyst flow amount per unit time of each fluidized bed layer.

[0046] In a traditional CO reactor, since the pipe diameters of the reactor inlet and outlet (including the pipe diameters of other sections or other positions) remain consistent, and the catalyst is fixedly loaded in the reactor, the cross-sectional area passed by the flue gas to be treated (such as sintering flue gas) entering the reactor from the reactor inlet (or flue gas inlet) to the reactor outlet (or flue gas outlet) is equal. Therefore, at different cross-sections perpendicular to the flue gas flow direction, the amount of catalyst contacted by the flue gas is equal. However, since the CO concentration in the flue gas is different at different cross-sections, the deactivation rate of the catalyst at different cross-sections is inconsistent. In other words, the deactivation time of the catalysts at different cross-sections is different, and the fixedly loaded catalyst needs to be replaced as a whole, which is bound to cause the problem of waste of catalysts when the whole is replaced, because some catalysts have been deactivated while some catalysts have not been deactivated, or the problem of some catalysts having been deactivated for a long time while some catalysts have just been deactivated, resulting in substandard CO removal in the flue gas. In addition, non-precious metal catalysts are easy to deactivate, and after deactivation, frequent shutdowns are required to manually replace the catalyst, which affects the system operating rate. Manual catalyst replacement is labor-intensive and is also a problem that needs to be solved urgently.

[0047] To address the issues of frequent downtime and manual replacement required when the aforementioned non-precious metal catalyst deactivates, as well as the need to replace the catalyst before it is fully utilized, the present invention proposes a CO fluidized bed reactor and a method for controlling catalyst flow. The technical solution of the present invention provides a CO fluidized bed reactor in which the catalyst freely flows from top to bottom. Fresh CO catalyst flows in from the top of the reactor, while deactivated CO catalyst flows out from the bottom, eliminating the need for downtime and manual replacement of the CO catalyst. The present invention also divides the CO2 fluidized bed reactor into multiple layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet. The service time of the catalyst in each layer of the fluidized bed increases layer by layer, that is, the flow rate of the catalyst in each layer of the fluidized bed (that is, the discharge or feed rate of the catalyst per unit time) decreases layer by layer, thereby causing the amount of effective catalyst in service in each layer of the fluidized bed per unit time to decrease layer by layer. By changing the amount of catalyst in each layer of the fluidized bed per unit time, the CO concentration (for example, mass concentration) at the inlet of the corresponding layer of the fluidized bed is adapted, thereby achieving the purpose of deactivating and discharging the catalyst in each layer of the fluidized bed after their respective different service times, realizing efficient utilization of the CO catalyst, effectively avoiding the waste of catalyst that occurs when the catalyst is replaced as a whole in a conventional reactor with fixed catalyst loading, and saving costs.

[0048] On the basis of the above-mentioned service time of the catalyst in each layer of the fluidized bed increasing layer by layer, the present invention further limits the CO fluidized bed reactor to be divided into multiple layers of fluidized beds of equal volume along the flue gas flow direction (i.e., the direction from the flue gas inlet to the flue gas outlet), i.e., the volume of the effective catalyst in each layer of the fluidized bed is the same, thereby further ensuring that the amount of effective catalyst in service per unit time in each layer of the fluidized bed is adapted to the CO concentration at the inlet of the corresponding layer of the fluidized bed, achieving the purpose of deactivating and discharging the catalyst in each layer of the fluidized bed after their respective different service times, thereby reducing catalyst waste. Figure 3 As shown, the volume of effective catalyst in each layer of fluidized bed is equal to the product of the catalyst cross-sectional area of the fluidized bed (i.e., the area of the surface perpendicular to the flue gas flow direction) and the catalyst thickness (i.e., the distance of the catalyst in the fluidized bed in the flue gas flow direction). Based on this, in order to facilitate the adjustment of the service time or flow rate of the catalyst in each layer of fluidized bed in the present application, the same volume of catalyst in each layer of fluidized bed can be specifically the same catalyst cross-sectional area of each layer of fluidized bed, and the corresponding catalyst thickness of each layer of fluidized bed is also the same or substantially the same.

[0049] In the CO fluidized bed reactor of the present invention, the CO catalyst is made into granular or cylindrical shape rather than the traditional honeycomb block shape, and the particle size is in the range of 1 to 20 mm, preferably in the range of 3 to 10 mm. The CO catalyst can flow freely in the reactor, thereby realizing automatic replacement of the CO catalyst without stopping the reactor for manual replacement.

[0050] In the present invention, the catalyst in the CO fluidized bed reactor is divided into multiple layers of fluidized beds along the flue gas flow direction, wherein the specific number of layers of the fluidized bed is not limited and can be designed and adjusted as needed (for example, according to factors such as the scale of the amount of flue gas to be treated, the CO concentration in the flue gas to be treated, etc.). For example, the CO fluidized bed reactor can be divided into 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, 7 layers, or 8 layers of fluidized beds, etc.

[0051] Further preferably, on the basis that the catalyst volume of each layer of the fluidized bed is the same, the present invention further includes the step of calculating the ratio of the catalyst flow rate of each layer of the fluidized bed in the CO fluidized bed reactor per unit time, specifically comprising: collecting the operating parameters of the flue gas to be treated, including the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, the mass concentration of CO in the flue gas to be treated, the mass concentration of O2 in the flue gas to be treated, etc.; based on these parameters, constructing a catalyst deactivation model, and calculating the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor by the model; in order to solve the problem that the existing CO reactor with fixed catalyst loading has the same pipe diameter The problem of catalyst waste caused by different deactivation rates of catalysts at different positions in the fluidized bed is solved. It is ensured that the catalysts in each layer of the fluidized bed in the CO fluidized bed reactor described in the present invention are deactivated and discharged after their respective different service times (that is, the deactivation rates of the catalysts discharged from each layer of the fluidized bed are required to be equal). The deactivation rates of the catalysts per unit volume discharged from each layer of the fluidized bed obtained by the above calculation are equal, that is, the deactivation rates of the catalysts discharged from each layer of the fluidized bed are close to the same, thereby calculating the ratio of the service time of the catalysts in each layer of the fluidized bed, and then calculating the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time, that is, obtaining the ratio of the catalyst flow amount of each layer of the fluidized bed per unit time. Among them, the constructed catalyst deactivation model is as follows:

[0052]

[0053] There are also:

[0054]

[0055] C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3);

[0056]

[0057] Combine the above formulas (1)-(5) to calculate the deactivation rate Q1, Q2, ..., Q of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor (a total of n layers of fluidized beds are divided). nAs mentioned above, the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed is equal, that is, Q1=Q2=……=Q n Given the number of layers n in the fluidized bed reactor, the ratio of the service time of the catalyst in each layer of the fluidized bed can be calculated: t1:t2:...:t n The catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same. Therefore, the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time is calculated as Z1:Z2:……:Z n =1 / t1:1 / t2:……1 / t n The CO fluidized bed reactor is provided with a discharge roller (e.g., an electric roller) at the discharge port position of each layer of the fluidized bed. The discharge speed ratio of the discharge roller of each layer of the fluidized bed is determined according to the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time. The deactivated catalyst in each layer of the fluidized bed flows out of the discharge port of the CO fluidized bed reactor through the discharge roller at the corresponding discharge speed ratio. At the same time, the fresh catalyst flows into each layer of the fluidized bed from the feed port above the CO fluidized bed reactor at the same discharge speed ratio, thus obtaining the ratio of the catalyst flow amount of each layer of the fluidized bed per unit time.

[0058] It should be noted that the catalyst deactivation model and related formulas constructed in the present invention are obtained by fitting by the inventors based on experiments and engineering applications. All calculations are based on numerical values converted according to given units, and the numerical values after conversion are substituted into the formulas for calculation (after conversion, only the numerical values are substituted into the formulas for calculation, without the units, and the units are only used to adjust the size of the numerical values).

[0059] For example, t in formula (1) i represents the service time of the catalyst in the i-th layer of fluidized bed, then Q calculated by formula (1) i The catalyst has been in service for a period of time t i Later, the deactivation rate of the catalyst per unit volume discharged from the i-th layer of fluidized bed at this time point is substituted into the data calculated by the formula t i Is dimensionless. Q1=Q2=……=Q n , which means that after the catalysts in each layer of the fluidized bed have served for different periods of time, the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed at the corresponding time point is equal. Taking non-precious metal CO catalysts as an example, since the catalysts are easily deactivated and have a short service life, the service life is measured in months, for example, t i =1 means that the service time of the catalyst in the i-th layer of fluidized bed is 1 month.

[0060] In the present invention, the service time of the catalyst in each layer of the fluidized bed in the CO fluidized bed reactor can be determined by real-time monitoring of the CO mass concentration in the clean flue gas discharged from the flue gas outlet: once the CO mass concentration detection in the clean flue gas begins to fail to meet the standard (for example, the target mass concentration of CO in the clean flue gas is set to ≤4000ppm, when the real-time monitored CO mass concentration is greater than 4000ppm, it means that the CO concentration in the clean flue gas discharged fails to meet the standard), it means that the catalyst activity in a certain layer of the fluidized bed in the CO fluidized bed reactor is no longer sufficient to support the normal removal of CO from the flue gas to be treated, and the service time of the catalyst in each layer of the fluidized bed increases from the reactor inlet to the reactor outlet, that is, the catalyst in the fluidized bed layer close to the reactor inlet is the first to be deactivated, that is, the corresponding catalyst deactivation time at this time is the service time t1 of the catalyst in the first layer of the fluidized bed. Combined with the ratio of the service time of the catalyst in each layer of the fluidized bed obtained by the above calculation, the specific service time t1, t2, ..., t n .

[0061] According to the specific service time t1, t2, ..., t n , calculate the catalyst flow rate per unit time in each fluidized bed layer. Specifically, based on the flue gas flow rate and space velocity ratio delivered to the CO fluidized bed reactor per unit time, the total amount of catalyst required to treat the CO in the original flue gas (i.e., the flue gas to be treated) can be estimated using formula (11), i.e., the effective catalyst loading in the CO fluidized bed reactor. Then, combining the number of fluidized bed layers in the CO fluidized bed reactor with the service life of the catalyst in each fluidized bed layer calculated above, the catalyst discharge rate per unit time in each fluidized bed layer can be estimated using formula (12). The CO fluidized bed reactor is provided with a discharge roller (such as an electric roller) at the discharge port position of each layer of the fluidized bed. The discharge speed of the discharge roller of the corresponding layer of the fluidized bed is determined according to the catalyst discharge amount of each layer of the fluidized bed per unit time. The deactivated catalyst in each layer of the fluidized bed flows out of the discharge port of the CO fluidized bed reactor through the discharge roller at the corresponding discharge speed. At the same time, the fresh catalyst flows into each layer of the fluidized bed from the feed port above the CO fluidized bed reactor at the same discharge speed, that is, the catalyst flow rate of each layer of the fluidized bed per unit time is obtained. During operation, the CO fluidized bed reactor is discharged and fed according to the catalyst flow rate of each layer of the fluidized bed per unit time, thereby ensuring that the clean flue gas obtained after the flue gas to be treated passes through the CO fluidized bed reactor meets the CO removal requirements. The relevant calculation formula is as follows:

[0062]

[0063] Where: V 催is the effective catalyst loading amount in the CO fluidized bed reactor, m 3 V is the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, m 3 / h. GHSV is the airspeed ratio, h -1 . Z i is the catalyst discharge amount per unit time of the i-th layer fluidized bed, m 3 / month. n is the number of fluidized bed layers in the CO fluidized bed reactor. i is the service time of the catalyst in the i-th layer of fluidized bed, measured in months.

[0064] Compared with the prior art, the present invention has the following beneficial technical effects:

[0065] 1. The present invention provides a CO2 fluidized bed reactor in which the catalyst is in a free-flowing state from top to bottom. Fresh CO2 catalyst flows in from the top of the reactor and deactivated CO2 catalyst flows out from the bottom of the reactor, eliminating the need to shut down the reactor for manual replacement of the CO2 catalyst.

[0066] 2. The present invention divides the CO fluidized bed reactor into multiple layers along the direction of flue gas flow. The service time of the catalyst in each layer of the fluidized bed increases layer by layer, that is, the flow rate of the catalyst in each layer of the fluidized bed decreases layer by layer, so that the amount of effective catalyst in service in each layer of the fluidized bed per unit time decreases layer by layer. By changing the amount of catalyst in each layer of the fluidized bed per unit time, the CO concentration at the inlet of the corresponding layer of the fluidized bed is adapted, so that the catalyst in each layer of the fluidized bed is deactivated and discharged after different service times, thereby achieving efficient utilization of the CO catalyst, effectively avoiding the waste of catalyst that occurs when the catalyst is replaced as a whole in traditional reactors with fixed catalysts, and saving costs.

[0067] 3. The present invention also provides a method for controlling the catalyst flow rate of each fluidized bed layer in a CO fluidized bed reactor. By establishing a mathematical model for catalyst deactivation, the deactivation rate of the catalyst per unit volume discharged from each fluidized bed layer is calculated, and the deactivation rate of the catalyst per unit volume discharged from each fluidized bed layer is set equal. The ratio of the service time of the catalysts in each fluidized bed layer is thus calculated, and the ratio of the catalyst discharge amount per unit time of each fluidized bed layer is further calculated, that is, the ratio of the catalyst flow rate per unit time of each fluidized bed layer is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 Schematic diagram of an existing honeycomb-type CO catalyst;

[0069] Figure 2 This is a schematic diagram of a fixed loading structure of the catalyst in an existing CO reactor;

[0070] Figure 3 Schematic diagram of the structure of the CO fluidized bed reactor in Example 10 of the present invention;

[0071] Figure 4 This is a flow chart of a method for controlling the flow rate of a catalyst in a CO fluidized bed reactor according to the present invention.

[0072] in: Figure 2 and Figure 3 The arrows in the figure indicate the direction of smoke flow.

[0073] Reference numerals:

[0074] 1: Shell; 101: Feeding section; 102: Reaction section; 103: Discharging section; 2: CO catalyst silo; 3: Perforated plate; 4: Electric roller. DETAILED DESCRIPTION

[0075] The technical solutions of the present invention are illustrated below with examples, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0076] Example 1

[0077] A method for controlling the flow rate of catalyst in a CO fluidized bed reactor is disclosed. Flue gas to be treated is transported to the CO fluidized bed reactor through a flue gas inlet. The flue gas entering the CO fluidized bed reactor undergoes a CO catalytic oxidation reaction under the action of a catalyst, and the clean flue gas, after removing CO, is discharged through a flue gas outlet. The catalyst within the CO fluidized bed reactor freely flows from top to bottom. The catalyst within the CO fluidized bed reactor is divided into multiple layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet, and the service life of the catalyst within each layer of the fluidized bed increases layer by layer.

[0078] Example 2

[0079] Example 1 was repeated, except that the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor was the same along the direction from the flue gas inlet to the flue gas outlet.

[0080] Example 3

[0081] Example 2 was repeated except that the catalyst cross-sectional area and catalyst thickness of each layer of the fluidized bed in the CO fluidized bed reactor were the same.

[0082] Example 4

[0083] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was in granular form. The particle size of the catalyst was 3 mm.

[0084] Example 5

[0085] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was in granular form. The particle size of the catalyst was 10 mm.

[0086] Example 6

[0087] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was in granular form. The particle size of the catalyst was 6 mm.

[0088] Example 7

[0089] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was cylindrical and had a particle size of 2 mm.

[0090] Example 8

[0091] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was cylindrical and had a particle size of 12 mm.

[0092] Example 9

[0093] Example 3 was repeated except that the catalyst in the CO fluidized bed reactor was cylindrical and had a particle size of 7 mm.

[0094] Example 10

[0095] A method for controlling the flow rate of catalyst in a CO2 fluidized bed reactor is described. Flue gas to be treated is delivered to the CO2 fluidized bed reactor through a flue gas inlet. The flue gas entering the CO2 fluidized bed reactor undergoes a CO catalytic oxidation reaction under the action of a catalyst, and the clean flue gas, after CO removal, is discharged through a flue gas outlet. The catalyst in the CO2 fluidized bed reactor freely flows from top to bottom. The flue gas to be treated is sintering flue gas from a steel plant.

[0096] The catalyst within the CO fluidized bed reactor is divided into three fluidized bed layers along the direction from the flue gas inlet to the flue gas outlet, and the service life of the catalyst in each fluidized bed layer increases with each layer. Specifically, the catalyst volume in each fluidized bed layer of the CO fluidized bed reactor is the same. Furthermore, the catalyst cross-sectional area and catalyst thickness in each fluidized bed layer of the CO fluidized bed reactor are the same.

[0097] In this embodiment, if Figure 3As shown, the CO fluidized bed reactor includes a shell 1. The shell 1 is provided with a feed section 101, a reaction section 102, and a discharge section 103 from top to bottom. A CO catalyst silo 2 is connected above the feed section 101. A plurality of porous plates 3 are vertically arranged in the reaction section 102. Along the direction of flue gas flow, the porous plates 3 evenly divide the reaction section 102 into three layers of fluidized beds, namely the first layer of fluidized bed, the second layer of fluidized bed, and the third layer of fluidized bed. A discharge section 103 is provided below each layer of fluidized bed, and a motorized roller 4 is provided at the bottom discharge port of the discharge section 103 corresponding to each layer of fluidized bed.

[0098] Example 11

[0099] Example 10 was repeated, except that the catalyst in the CO fluidized bed reactor was divided into 6 layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet.

[0100] Example 12

[0101] Example 10 was repeated, except that the catalyst in the CO fluidized bed reactor was divided into four layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet.

[0102] Example 13

[0103] Example 10 was repeated except that the flue gas to be treated was cement kiln tail gas.

[0104] Example 14

[0105] Example 10 was repeated except that the flue gas to be treated was blast furnace tail gas.

[0106] Example 15

[0107] Example 10 was repeated, except that the method further included the step of calculating the ratio of the catalyst flow rate per unit time of each layer of the fluidized bed in the CO fluidized bed reactor, specifically comprising:

[0108] S1. Collecting the working parameters of the flue gas to be treated: detecting the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, the mass concentration of CO in the flue gas to be treated, and the mass concentration of O2 in the flue gas to be treated.

[0109] S2. Based on the operating parameters of the flue gas to be treated, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor.

[0110] S3. Based on the fact that the deactivation rate per unit volume of catalyst discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, the ratio of the service time of the catalysts in each layer of the fluidized bed is calculated, thereby deducing the ratio of the catalyst discharge amount per unit time of each layer of the fluidized bed, that is, the ratio of the catalyst flow amount per unit time of each layer of the fluidized bed is obtained.

[0111] Example 16

[0112] like Figure 4 As shown, Example 10 is repeated, except that the method further includes the step of calculating the catalyst flow rate ratio of each layer of the fluidized bed in the CO fluidized bed reactor per unit time, specifically including:

[0113] S1. Collecting the working parameters of the flue gas to be treated: detecting the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, the mass concentration of CO in the flue gas to be treated, and the mass concentration of O2 in the flue gas to be treated.

[0114] Wherein, step S1 is specifically as follows:

[0115] Collect the working parameters of the flue gas to be treated: set up a flue gas flow detection device, a CO concentration detection device, and an O2 concentration detection device at the flue gas inlet of the CO fluidized bed reactor. Among them, the flue gas flow detection device detects the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, which is recorded as V = 1200000m 3 / h. The CO concentration detection device detects the mass concentration of CO in the flue gas to be treated, which is recorded as C co =10000mg / m 3 The O2 concentration detection device detects the mass concentration of O2 in the flue gas to be treated, which is recorded as

[0116] S2. Based on the operating parameters of the flue gas to be treated, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor.

[0117] Wherein, step S2 is specifically as follows:

[0118] According to the operating parameters of the flue gas to be treated, a catalyst deactivation model is established:

[0119]

[0120] in:

[0121]

[0122] C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3).

[0123]

[0124] Where: Q i is the deactivation rate per unit volume of catalyst discharged from the i-th layer of the fluidized bed in the CO fluidized bed reactor, m / h. R is the catalyst activity constant. The catalyst used is specifically Ce-Cu / γ-Al2O3 non-precious metal catalyst, R = 0.4. v is the catalyst surface velocity of each layer of fluidized bed, m / h. i is the service time of the catalyst in the i-th layer of fluidized bed, in months. icoin is the CO mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 b1 is the adjustment coefficient, b1 = 1 / 2880. V is the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, V = 1200000m 3 / h. A is the catalyst cross-sectional area of each layer of the fluidized bed. In this embodiment, A=10×10=100m 2 . C (i+1)coin is the CO mass concentration at the inlet of the i+1th layer fluidized bed, mg / m 3 . C icoout is the CO mass concentration at the outlet of the i-th layer fluidized bed, mg / m 3 η i is the CO catalytic oxidation efficiency in the i-th fluidized bed. n is the number of fluidized bed layers in the CO fluidized bed reactor, n = 3. b2 is the correction factor, b2 = 0.5 m / h. is the O2 mass concentration at the inlet of the i+1 layer fluidized bed, mg / m 3 . M co is the molar mass of CO, M co =28g / mol. is the molar mass of O2, M O2 =32g / mol.

[0125] Formulas (1)-(5) are combined to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor:

[0126] Deactivation rate of catalyst per unit volume discharged from the first layer of fluidized bed:

[0127]

[0128] Where: Q1 is the deactivation rate of the catalyst per unit volume discharged from the first layer of fluidized bed, m / h. t1 is the service time of the catalyst in the first layer of fluidized bed, in months.1coin is the CO mass concentration at the inlet of the first layer of fluidized bed, C 1coin =C co =10000mg / m 3 . is the O2 mass concentration at the inlet of the first layer of fluidized bed,

[0129] The deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed:

[0130]

[0131] in:

[0132] C 2coin =C 1coout =C 1coin ×(1-η1).

[0133]

[0134] Where: Q2 is the deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed, m / h. t2 is the service time of the catalyst in the second layer of fluidized bed, in months. 2coin is the CO mass concentration at the inlet of the second layer of fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the second layer fluidized bed, mg / m 3 .

[0135] The deactivation rate of the catalyst per unit volume discharged from the third layer of fluidized bed:

[0136]

[0137] in:

[0138] C 3coin =C 2coout =C 2coin ×(1-η2).

[0139]

[0140] Where: Q3 is the deactivation rate of the catalyst per unit volume discharged from the third layer of fluidized bed, m / h. t3 is the service time of the catalyst in the third layer of fluidized bed, in months. 3coin is the CO mass concentration at the inlet of the third layer fluidized bed, mg / m 3 . is the O2 mass concentration at the inlet of the third layer fluidized bed, mg / m 3 .

[0141] S3. Based on the fact that the deactivation rate per unit volume of catalyst discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, the ratio of the service time of the catalysts in each layer of the fluidized bed is calculated, thereby deducing the ratio of the catalyst discharge amount per unit time of each layer of the fluidized bed, that is, the ratio of the catalyst flow amount per unit time of each layer of the fluidized bed is obtained.

[0142] Wherein, step S3 is specifically as follows:

[0143] Based on the fact that the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, we can obtain:

[0144] Q1=Q2=Q3…………(9). 0

[0145] The above formula is used to calculate the ratio of the service time of the catalyst in each layer of the fluidized bed, t1:t2:t3=1.48:2.50:4.94.

[0146] Since the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same, the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time is calculated as follows:

[0147]

[0148] Where: Z1 is the catalyst discharge of the first layer of fluidized bed per unit time, m 3 / month. Z2 is the catalyst discharge of the second layer of fluidized bed per unit time, m 3 / month. Z3 is the catalyst discharge of the third layer of fluidized bed per unit time, m 3 / month.

[0149] The CO2 fluidized bed reactor is equipped with electric rollers at the discharge port of each fluidized bed layer. The discharge speed ratio of the electric rollers in each fluidized bed layer is determined based on the ratio of the catalyst discharge amount per unit time in each fluidized bed layer. Deactivated catalyst in each fluidized bed layer flows out of the discharge port of the CO2 fluidized bed reactor through the electric rollers at the corresponding discharge speed ratio. Simultaneously, fresh catalyst flows into each fluidized bed layer from the feed port above the CO2 fluidized bed reactor at the same discharge speed ratio. This determines the ratio of the catalyst flow amount per unit time in each fluidized bed layer.

Claims

1. A method for controlling the flow rate of a catalyst in a CO fluidized bed reactor, characterized in that: The flue gas to be treated is transported to the CO fluidized bed reactor through the flue gas inlet. The flue gas to be treated in the CO fluidized bed reactor undergoes a CO catalytic oxidation reaction under the action of the catalyst, and the clean flue gas after CO removal is discharged from the flue gas outlet. The catalyst in the CO fluidized bed reactor is in a free-flowing state from top to bottom. The catalyst in the CO fluidized bed reactor is divided into multiple layers of fluidized beds along the direction from the flue gas inlet to the flue gas outlet, and the service life of the catalyst in each layer of the fluidized bed increases layer by layer.

2. The catalyst flow control method according to claim 1, characterized in that: Along the direction from the flue gas inlet to the flue gas outlet, the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same.

3. The catalyst flow control method according to claim 2, characterized in that: The catalyst cross-sectional area and catalyst thickness of each layer of the fluidized bed in the CO fluidized bed reactor are the same.

4. The catalyst flow control method according to any one of claims 1 to 3, characterized in that: The catalyst in the CO fluidized bed reactor is granular or cylindrical; preferably, the particle size of the catalyst is 1 to 20 mm, preferably 3 to 10 mm.

5. The catalyst flow control method according to any one of claims 1 to 4, characterized in that: Along the direction from the flue gas inlet to the flue gas outlet, the catalyst in the CO fluidized bed reactor is divided into n layers of fluidized beds, wherein n is 2 to 8, preferably 3 to 6.

6. The catalyst flow control method according to any one of claims 1 to 5, characterized in that: The flue gas to be treated is flue gas containing CO; preferably, the flue gas to be treated is flue gas containing CO and O2; further preferably, the flue gas to be treated is one of sintering flue gas, cement kiln exhaust gas, and blast furnace exhaust gas.

7. The catalyst flow control method according to any one of claims 3 to 6, characterized in that: The method also includes the step of calculating the catalyst flow rate ratio per unit time of each layer of the fluidized bed in the CO fluidized bed reactor, specifically comprising: S1. Collecting the operating parameters of the flue gas to be treated: detecting the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, the mass concentration of CO in the flue gas to be treated, and the mass concentration of O2 in the flue gas to be treated; S2. Establish a catalyst deactivation model based on the operating parameters of the flue gas to be treated, and calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor; S3. Based on the fact that the deactivation rate per unit volume of catalyst discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, the ratio of the service time of the catalysts in each layer of the fluidized bed is calculated, thereby deducing the ratio of the catalyst discharge amount per unit time of each layer of the fluidized bed, that is, the ratio of the catalyst flow amount per unit time of each layer of the fluidized bed is obtained.

8. The catalyst flow control method according to claim 7, characterized in that: Step S1 is specifically as follows: Collect the working parameters of the flue gas to be treated: set up a flue gas flow detection device, a CO concentration detection device, and an O2 concentration detection device at the flue gas inlet of the CO fluidized bed reactor; among them, the flue gas flow detection device detects the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, which is recorded as V, m 3 / h; CO concentration detection device detects the mass concentration of CO in the flue gas to be treated, recorded as C co , mg / m 3 ; The O2 concentration detection device detects the mass concentration of O2 in the flue gas to be treated, which is recorded as C O2 , mg / m 3 .

9. The catalyst flow control method according to claim 8, characterized in that: Step S2 is specifically as follows: According to the operating parameters of the flue gas to be treated, a catalyst deactivation model is established: in: C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3); Where: Q i is the deactivation rate of the catalyst per unit volume discharged from the i-th layer of the CO fluidized bed reactor, m / h; R is the catalyst activity constant, and the value range of R is 0.2~2; A v is the catalyst surface velocity of each layer of fluidized bed, m / h; t i is the service time of the catalyst in the i-th layer of fluidized bed, in months; C icoin is the CO mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 ; C iO2 is the O2 mass concentration at the inlet of the i-th layer fluidized bed, mg / m 3 ; b1 is the adjustment coefficient, and the value range of b1 is 1 / 2700~1 / 3700; V is the flow rate of the flue gas to be treated delivered to the CO fluidized bed reactor per unit time, m 3 / h; A is the catalyst cross-sectional area of each layer of fluidized bed, m 2 ; C (i+1)coin is the CO mass concentration at the inlet of the i+1th layer fluidized bed, mg / m 3 ; C icoout is the CO mass concentration at the outlet of the i-th layer fluidized bed, mg / m 3 ;η i is the CO catalytic oxidation efficiency in the i-th fluidized bed; n is the number of fluidized bed layers in the CO fluidized bed reactor; b2 is the correction coefficient, and the value range of b2 is 0.3~0.5m / h; is the O2 mass concentration at the inlet of the i+1 layer fluidized bed, mg / m 3 ;M co is the molar mass of CO, g / mol; M O2 is the molar mass of O2, g / mol; Formulas (1)-(5) are combined to calculate the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor: Deactivation rate of catalyst per unit volume discharged from the first layer of fluidized bed: Where: Q1 is the deactivation rate of the catalyst per unit volume discharged from the first layer of fluidized bed, m / h; t1 is the service time of the catalyst in the first layer of fluidized bed, in months; C 1coin is the CO mass concentration at the inlet of the first layer of fluidized bed, mg / m 3 ; is the O2 mass concentration at the inlet of the first layer of fluidized bed, mg / m 3 ; The deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed: Where: Q2 is the deactivation rate of the catalyst per unit volume discharged from the second layer of fluidized bed, m / h; t2 is the service time of the catalyst in the second layer of fluidized bed, in months; C 2coin is the CO mass concentration at the inlet of the second layer of fluidized bed, mg / m 3 ; is the O2 mass concentration at the inlet of the second layer fluidized bed, mg / m 3 ; …… The deactivation rate of the catalyst per unit volume discharged from the nth layer of fluidized bed: Where: Q n is the deactivation rate of the catalyst per unit volume discharged from the nth layer of fluidized bed, m / h; t n is the service time of the catalyst in the nth layer of fluidized bed, in months; C ncoin is the CO mass concentration at the inlet of the nth layer fluidized bed, mg / m 3 ; is the O2 mass concentration at the inlet of the nth layer fluidized bed, mg / m 3 .

10. The catalyst flow control method according to claim 9, characterized in that: Step S3 is specifically as follows: Based on the fact that the deactivation rate of the catalyst per unit volume discharged from each layer of the fluidized bed in the CO fluidized bed reactor is equal, we can obtain: Q1=Q2=……=Q n …………(9); Set the number of fluidized bed layers n in the CO fluidized bed reactor and calculate the ratio of the catalyst service time in each layer of the fluidized bed: t1: t2: ...: t n ; Since the catalyst volume of each layer of the fluidized bed in the CO fluidized bed reactor is the same, the ratio of the catalyst discharge amount of each layer of the fluidized bed per unit time is calculated as follows: Where: Z1 is the catalyst discharge of the first layer of fluidized bed per unit time, m 3 / month; Z2 is the catalyst discharge of the second layer of fluidized bed per unit time, m 3 / month; Z n is the catalyst discharge amount per unit time of the nth layer fluidized bed, m 3 / moon; The CO fluidized bed reactor is provided with a discharge roller (e.g., a motorized roller) at the discharge port of each fluidized bed layer. The discharge speed ratio of the discharge rollers of each fluidized bed layer is determined based on the ratio of the catalyst discharge amount of each fluidized bed layer per unit time. The deactivated catalyst in each fluidized bed layer flows out of the discharge port of the CO fluidized bed reactor through the discharge rollers at the corresponding discharge speed ratio. At the same time, fresh catalyst flows into each fluidized bed layer from the feed port above the CO fluidized bed reactor at the same discharge speed ratio. Thus, the ratio of the catalyst flow amount of each fluidized bed layer per unit time is obtained.

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