Reducing control method of CO reducing reactor

Abstract

A reducing control method of a CO reducing reactor is characterized in that raw flue gas is conveyed to the CO reducing reactor through a flue gas inlet, the raw flue gas entering the CO reducing reactor is subjected to a CO removal reaction under the action of a catalyst, and purified flue gas after CO removal is discharged from a flue gas outlet; wherein in the direction from the flue gas inlet to the flue gas outlet, the CO reducing reactor is arranged to be a multi-layer reactor, and the volume of each layer of reactor is gradually reduced layer by layer. According to the invention, the conventional CO reactor with consistent pipe diameter is subjected to variable-diameter adjustment, and the volume of each layer of reactor is gradually reduced layer by layer, so that the amount of a catalyst filled in each layer of reactor is gradually reduced layer by layer, and the purpose that the inactivation rate of the catalyst in each layer of reactor is approximately consistent is achieved; therefore, the condition that part of the catalyst is not inactivated and the catalyst is wasted when the catalyst of the traditional reactor is integrally replaced is avoided, so that the CO catalyst is efficiently utilized, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to a CO reactor, in particular to a diameter-changing control method of a CO variable-diameter reactor, and belongs to the technical fields of chemical engineering and environmental protection. Background Art

[0002] During the CO removal reaction in flue gas, the CO oxidation reaction is an exothermic reaction, resulting in a higher reactor outlet temperature than the reactor inlet temperature. Furthermore, 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 results in inconsistent catalyst deactivation rates at different locations within the reactor. Catalyst deactivation is affected by factors such as temperature, CO concentration, and operating conditions. Near the reactor inlet, where the CO concentration is high and the temperature is low, the catalyst is more susceptible to deactivation due to carbon deposits or other impurities. Meanwhile, near the reactor outlet, where the temperature is higher, the CO concentration is low, allowing the catalyst to maintain its activity longer.

[0003] Conventional CO reactors are typically designed based on SCR reactors, with consistent pipe diameters at the reactor inlet and outlet. Under this design, during the CO removal reaction from flue gas, the catalyst near the reactor inlet may deactivate, necessitating the complete replacement of the fixed catalyst within the reactor. Meanwhile, the catalyst near the reactor outlet has not yet fully deactivated, and this portion of the catalyst is replaced before being fully utilized, resulting in catalyst waste. For example, using a Pt-loaded precious metal CO catalyst, this existing design results in wasted catalyst at the reactor outlet, underutilizing the catalyst, reducing the unit Pt utilization rate, and significantly increasing costs. Furthermore, in this scenario, if some catalyst within the reactor remains undeactivated and is continued in use until fully deactivated, the flue gas treatment effect will be severely impacted, resulting in CO concentrations in the flue gas at the reactor outlet failing to meet removal requirements and comply with environmental regulations. This not only increases operating costs but also potentially poses environmental risks and legal risks. Therefore, improving reactor design and catalyst utilization to address the uneven catalyst deactivation rates, improve catalyst utilization efficiency, reduce costs, and ensure flue gas treatment effectiveness has become an urgent technical challenge. Summary of the Invention

[0004] In response to the technical problem of catalyst waste caused by the fixed loaded catalyst not being fully utilized and needing to be replaced in the above-mentioned prior art, the present invention proposes a CO variable diameter reactor and its variable diameter control method. In the technical solution of the present invention, the traditional CO reactor with a uniform pipe diameter is adjusted to a variable diameter, and a CO variable diameter reactor is proposed. The CO variable diameter reactor is set as a multi-layer reactor. Along the direction from the flue gas inlet to the flue gas outlet, the volume of each layer of reactor decreases layer by layer, so that the amount of catalyst loaded in each layer of reactor decreases layer by layer. By changing the amount of catalyst in each layer of reactor, the CO concentration (for example, mass concentration) at the inlet of the corresponding layer of reactor is adapted, so as to achieve the purpose of nearly consistent deactivation rate of the catalyst in each layer of reactor, thereby avoiding the situation in which some catalysts are not deactivated and catalysts are wasted when the catalyst is replaced as a whole in the traditional reactor, so that the CO catalyst is efficiently utilized and the cost is reduced.

[0005] According to an embodiment of the present invention, a method for controlling the diameter variation of a CO variable diameter reactor is provided.

[0006] A method for controlling the diameter variation of a CO variable diameter reactor is disclosed. Raw flue gas is transported to the CO variable diameter reactor through a flue gas inlet. The raw flue gas entering the CO variable diameter reactor undergoes a CO removal reaction under the action of a catalyst, and the clean flue gas after CO removal is discharged from the flue gas outlet. The CO variable diameter reactor is configured as a multi-layer reactor from the flue gas inlet to the flue gas outlet, with the volume of each layer decreasing gradually.

[0007] In the present invention, along the direction from the flue gas inlet to the flue gas outlet, the cross-sectional area of each layer of reactors in the CO variable diameter reactor decreases layer by layer.

[0008] In the present invention, in the CO variable diameter reactor, the heights of the reactors in each layer are the same.

[0009] In the present invention, along the direction from the flue gas inlet to the flue gas outlet, the CO variable diameter reactor is configured as an n-layer reactor, wherein n is 2 to 8, preferably 3 to 6.

[0010] In the present invention, the method further includes the step of calculating the diameter ratio of the CO variable diameter reactor, specifically comprising:

[0011] S1. Collect the working parameters of the original flue gas: detect the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, the mass concentration of CO in the original flue gas, and the mass concentration of O2 in the original flue gas.

[0012] S2. Based on the operating parameters of the original flue gas, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor.

[0013] S3. Based on the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, the ratio of the cross-sectional areas of the reactors in each layer is calculated to obtain the variable diameter ratio of the CO variable diameter reactor.

[0014] In the present invention, step S1 is specifically as follows:

[0015] Collect the working parameters of the original flue gas: 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 variable diameter reactor. Among them, the flue gas flow detection device detects the original flue gas flow rate delivered to the CO variable diameter 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 original flue gas, which is recorded as C co , mg / m 3 The O2 concentration detection device detects the mass concentration of O2 in the original flue gas, which is recorded as C O2 , mg / m 3 .

[0016] In the present invention, step S2 is specifically as follows:

[0017] According to the operating parameters of the original flue gas, the catalyst deactivation model is established:

[0018]

[0019] in:

[0020]

[0021] C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3).

[0022]

[0023] Where: Q i A is the deactivation rate of the catalyst per unit volume in the i-th layer of the CO variable diameter 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. vi is the catalyst surface velocity in the i-th layer reactor, m / h. t is the service time of the catalyst in the CO variable diameter reactor, in years. icoin is the CO mass concentration at the inlet of the reactor at layer i, mg / m 3 . is the O2 mass concentration at the inlet of the i-th layer reactor, mg / m 3b1 is the adjustment coefficient, and the value range of b1 is 1 / 2700~1 / 3700. V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, m 3 / h. A i is the cross-sectional area of the catalyst in the reactor layer i, m 2 . C (i+1)coin is the CO mass concentration at the inlet of the i+1 layer reactor, mg / m 3 . C icoout is the CO mass concentration at the outlet of the reactor at layer i, mg / m 3 η i is the CO catalytic oxidation efficiency in the i-th reactor. n is the number of reactor layers in the CO variable-diameter reactor. b2 is the correction factor, and the value of b2 ranges from 0.3 to 0.5 h / m. is the O2 mass concentration at the inlet of the i+1 layer reactor, mg / m 3 . M co is the molar mass of CO, g / mol. M O2 is the molar mass of O2, g / mol.

[0024] Formulas (1)-(5) are combined to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor:

[0025] Deactivation rate of catalyst per unit volume in the first reactor:

[0026]

[0027] Where: Q1 is the deactivation rate of the catalyst per unit volume in the first reactor, m / h. A1 is the cross-sectional area of the catalyst in the first reactor, m 2 . C 1coin is the CO mass concentration at the inlet of the first layer reactor, mg / m 3 . is the O2 mass concentration at the inlet of the first layer reactor, mg / m 3 .

[0028] The deactivation rate of catalyst per unit volume in the second reactor:

[0029]

[0030] Where: Q2 is the deactivation rate of the catalyst per unit volume in the second reactor, m / h. A2 is the cross-sectional area of the catalyst in the second reactor, m 2 . C 2coin is the CO mass concentration at the inlet of the second layer reactor, mg / m 3 . is the O2 mass concentration at the inlet of the second layer reactor, mg / m3 .

[0031] …

[0032] The deactivation rate of catalyst per unit volume in the nth layer reactor:

[0033]

[0034] Where: Q n A is the deactivation rate of catalyst per unit volume in the nth layer reactor, m / h. n is the cross-sectional area of the catalyst in the nth layer reactor, m 2 . C ncoin is the CO mass concentration at the inlet of the nth layer reactor, mg / m 3 . is the O2 mass concentration at the inlet of the nth layer reactor, mg / m 3 .

[0035] In the present invention, step S3 is specifically as follows:

[0036] According to the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, we can get:

[0037] Q1=Q2=……=Q n …………(9).

[0038] Set the number of reactor layers n in the CO variable diameter reactor and calculate the ratio of the cross-sectional area of each layer of reactor A1:A2:...:A n , that is, the diameter ratio of the CO variable diameter reactor is obtained.

[0039] In the present invention, the method further comprises:

[0040] S4. Based on the raw flue gas flow rate and space velocity ratio delivered to the CO variable diameter reactor per unit time, the total amount of catalyst required to treat the CO in the raw flue gas, i.e., the catalyst loading amount in the CO variable diameter reactor, is calculated. Then, the height of each layer of reactors in the CO variable diameter reactor is set, and the cross-sectional area of each layer of reactors in the CO variable diameter reactor is calculated based on the ratio of the cross-sectional area of each layer of reactors. That is,

[0041]

[0042] (A1+A2+……+A n )×h=V 催 …………(11).

[0043] Where: V 催 is the loading amount of catalyst in the CO variable diameter reactor, m 3V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, m 3 / h. GHSV is the airspeed ratio, h -1 A1 is the cross-sectional area of the catalyst in the first layer of the reactor, m 2 A2 is the cross-sectional area of the catalyst in the second layer of the reactor, m 2 . A n is the cross-sectional area of the catalyst in the nth layer reactor, m 2 . h is the height of each layer of reactor, m.

[0044] Combining formulas (10) and (11), the cross-sectional areas A1, A2, ..., A of each layer of the CO variable diameter reactor are obtained. n .

[0045] In the present invention, the raw flue gas is flue gas containing CO. Preferably, the raw flue gas is flue gas containing CO and O2. More preferably, the raw flue gas is one of sintering flue gas, cement kiln exhaust gas, and blast furnace exhaust gas.

[0046] In a traditional CO reactor, since the diameters of the reactor inlet and outlet (including the diameters of other sections or other positions) are consistent, and the catalyst is fixedly loaded in the reactor, the cross-sectional area passed by the original flue gas (i.e., 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, so the amount of catalyst contacted by the flue gas at different cross-sections perpendicular to the flue gas flow direction is equal, but 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 (it should be noted that the deactivation of the catalyst is affected by factors such as CO concentration, temperature, and operating conditions, but in the reaction system of the present application, CO concentration is the main influencing factor). 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 catalyst when the whole is replaced, because some catalysts have been deactivated for a long time while some catalysts have not been deactivated, or the problem of substandard CO removal in the flue gas due to some catalysts having been deactivated for a long time while some catalysts have just been deactivated.

[0047] In response to the technical problem of catalyst waste caused by the fixed CO catalyst not being fully utilized and needing to be replaced, the present invention proposes a CO variable diameter reactor and a method for controlling the diameter thereof. In the technical solution of the present invention, a conventional CO reactor with a uniform diameter is adjusted to a variable diameter, and a CO variable diameter reactor is proposed. The CO variable diameter reactor is configured as a multi-layer reactor. The volume of each layer of reactor decreases layer by layer along the direction from the flue gas inlet to the flue gas outlet, thereby causing the amount of catalyst loaded in each layer of reactor to decrease layer by layer. By changing the amount of catalyst in each layer of reactor, the CO concentration at the inlet of the corresponding layer of reactor is adapted, thereby achieving the purpose of nearly consistent deactivation rate of the catalyst in each layer of reactor, thereby avoiding the situation in which some catalyst is not deactivated and catalyst is wasted when the catalyst is replaced as a whole in conventional reactors, thereby achieving efficient utilization of CO catalyst and reducing costs.

[0048] It should be noted that, in the present invention, the "diameter change" of the CO variable diameter reactor is not limited to a specific shape, structure, direction or position. For example, it can be a diameter change based on a cylindrical structure, or a diameter change based on a cubic structure, or a lateral diameter change, or a vertical diameter change, or a change in the outer diameter of the reactor, or a change in the inner diameter of the reactor (for example, the inner diameter changes due to filling other non-catalyst substances inside), etc. It only needs to be that the "diameter change" is along the direction of flue gas flow (i.e., from the flue gas inlet to the flue gas outlet), and the volume of the reactor at different levels can be changed along this direction, thereby changing the amount of effective catalyst at the corresponding position, and ultimately achieving the purpose of gradually decreasing the amount of catalyst loaded in each layer of the reactor along the direction of flue gas flow.

[0049] Preferably, when the CO variable diameter reactor is adjusted by changing the diameter of the traditional cubic structure or cylindrical structure, the volume of each layer of the reactor is equal to the product of the cross-sectional area of the reactor in that layer (that is, the area of the surface perpendicular to the direction of flue gas flow) and the height. Based on this, in order to facilitate the variable diameter design of the variable diameter reactor described in this application, the volume of each layer of the reactor decreases layer by layer, which can be specifically a cross-sectional area decreases layer by layer, while the height of the corresponding reactors in each layer is the same or substantially the same.

[0050] In the present invention, the CO variable diameter reactor is set as a multi-layer reactor along the flue gas flow direction, wherein the specific number of layers of the reactor is not limited and can be designed and adjusted as needed (for example, according to factors such as the scale of the original flue gas to be processed, the CO concentration in the original flue gas, etc.). For example, the CO variable diameter reactor can be set as a 2-layer, 3-layer, 4-layer, 5-layer, 6-layer, 7-layer, or 8-layer reactor, etc.

[0051] Further preferably, on the basis that the cross-sectional area of each layer of reactors decreases layer by layer and the height is the same, the present invention further includes a step of calculating the diameter ratio of the CO variable diameter reactor, specifically comprising: collecting the operating parameters of the original flue gas, including the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, the mass concentration of CO in the original flue gas, the mass concentration of O2 in the original flue gas, etc.; based on these parameters, constructing a catalyst deactivation model, and calculating the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor by the model; in order to solve the problem of the catalyst at different positions in the existing CO reactor with the same pipe diameter, The problem of catalyst waste caused by different deactivation rates of the catalysts is solved. It is ensured that the catalysts in each layer of the CO variable diameter reactor described in the present invention are deactivated when the catalyst is replaced as a whole (that is, the deactivation rate of the catalysts in each layer of the reactor is required to be consistent). The deactivation rate of the catalyst per unit volume in each layer of the reactor calculated above is equal, that is, the deactivation rate of the catalyst in each layer of the reactor is close to the same, thereby calculating the ratio of the cross-sectional areas of each layer of the reactor, that is, obtaining the diameter ratio of the CO variable diameter reactor, realizing the diameter control of the CO variable diameter reactor, and making the CO catalyst more efficiently utilized. 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 rates Q1, Q2, ..., Q2 of the catalyst per unit volume in each layer of the CO variable diameter reactor (a total of n layers of reactors are set) respectively. n As mentioned above, the deactivation rate of the catalyst per unit volume in each reactor layer is equal, that is, Q1 = Q2 = ... = Q n , based on the number of reactor layers n in a given CO variable diameter reactor, the ratio of the cross-sectional area of each layer of reactor A1:A2:……:A can be calculated. n , that is, the diameter ratio of the CO variable diameter reactor is obtained.

[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) represents the service time of the catalyst in the CO variable diameter reactor. Then, the Q calculated by formula (1) is i That is, the deactivation rate of the catalyst per unit volume in the reactor layer i at this time point after the catalyst has been in service for a period of time t. The data t calculated by substituting it into the formula is dimensionless. Q1=Q2=……=Q n , meaning that after a service time t, the catalysts in each reactor layer have experienced equal deactivation rates per unit volume. For example, the Pt-supported precious metal CO catalyst has a long service life, so the service time is measured in years. For example, t = 1 means the catalyst has been in service for one year.

[0060] After obtaining the diameter ratio of the above-mentioned reactor, the CO variable diameter reactor of the present invention can be designed according to this diameter ratio. Specifically, the total amount of catalyst required to treat CO in the original flue gas, that is, the loading amount of the catalyst in the CO variable diameter reactor, can be calculated by formula (10) based on the original flue gas flow rate and space velocity ratio transported to the CO variable diameter reactor per unit time. Then, the height of each layer of reactors in the CO variable diameter reactor is set, and the cross-sectional area of each layer of reactors is calculated by combining the ratio of the cross-sectional area of each layer of reactors obtained by the above calculation with formula (11), thereby obtaining the cross-sectional area, height and other dimensional design data of each layer of reactors in the CO variable diameter reactor, so as to ensure that the net flue gas obtained after the original flue gas passes through the CO variable diameter reactor meets the CO removal requirements. The relevant calculation formula is as follows:

[0061]

[0062] (A1+A2+……+A n )×h=V 催 …………(11).

[0063] In the present invention, the overall replacement time of the catalyst in the CO variable diameter reactor can be determined by real-time monitoring of the CO mass concentration in the clean flue gas discharged from the flue gas outlet: when the CO mass concentration in the clean flue gas is not up to 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 is not up to standard), it means that the catalyst activity in the CO variable diameter reactor is no longer sufficient to support the normal removal of CO from the original flue gas. At this time, the catalyst in the CO variable diameter reactor needs to be replaced as a whole; on the contrary, when the CO mass concentration in the clean flue gas is up to standard (for example, the real-time monitored CO mass concentration is ≤4000ppm), it means that the catalyst in the CO variable diameter reactor has not been deactivated and does not need to be replaced at this time, thereby avoiding waste of catalyst and saving costs.

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

[0065] 1. The present invention makes a variable diameter adjustment to the traditional CO reactor with a uniform tube diameter. That is, the CO variable diameter reactor is arranged as a multi-layer reactor along the direction of flue gas flow. The volume of each layer of reactor decreases layer by layer, so that the amount of catalyst loaded in each layer of reactor decreases layer by layer. By changing the amount of catalyst in each layer of reactor, the CO concentration at the inlet of the corresponding layer of reactor is adapted, so as to achieve the purpose of nearly consistent deactivation rate of the catalyst in each layer of reactor. This avoids the situation in which some catalysts are not deactivated and waste catalysts when the catalyst is replaced as a whole in the traditional reactor, so that the CO catalyst is efficiently utilized and the cost is reduced.

[0066] 2. The present invention also provides a method for controlling the diameter variation of a CO variable diameter reactor. By establishing a mathematical model for catalyst deactivation, the deactivation rate of the catalyst per unit volume in each layer of the reactor is calculated, and the deactivation rate of the catalyst per unit volume in each layer of the reactor is set equal, thereby calculating the ratio of the cross-sectional areas of the reactors in each layer, that is, obtaining the diameter variation ratio of the CO variable diameter reactor.

[0067] 3. The present invention also provides a specific calculation method for the cross-sectional area of each layer of reactors in the CO variable diameter reactor. Based on the original flue gas flow rate and space velocity ratio delivered to the CO variable diameter reactor per unit time, the total amount of catalyst required to treat CO in the original flue gas is calculated. Combined with the ratio of the cross-sectional areas of each layer of reactors, the cross-sectional area of each layer of reactors is then inferred. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 Schematic diagram of the structure of a traditional CO reactor;

[0069] Figure 2 Schematic diagram of the structure of the CO variable diameter reactor in Example 4 of the present invention;

[0070] Figure 3 This is a flow chart of a method for controlling a variable diameter CO reactor according to the present invention;

[0071] in: Figure 1 and Figure 2 The arrows in the figure indicate the direction of smoke flow. DETAILED DESCRIPTION

[0072] 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.

[0073] Example 1

[0074] A method for controlling the diameter variation of a CO variable diameter reactor is disclosed. Raw flue gas is transported to the CO variable diameter reactor through a flue gas inlet. The raw flue gas entering the CO variable diameter reactor undergoes a CO removal reaction under the action of a catalyst, and the clean flue gas after CO removal is discharged from the flue gas outlet. The CO variable diameter reactor is configured as a multi-layer reactor from the flue gas inlet to the flue gas outlet, with the volume of each layer decreasing gradually.

[0075] Example 2

[0076] Example 1 was repeated, except that the cross-sectional area of each layer of the reactor in the CO variable diameter reactor decreased layer by layer along the direction from the flue gas inlet to the flue gas outlet.

[0077] Example 3

[0078] Example 2 was repeated, except that in the CO variable diameter reactor, the heights of the reactors in each layer were the same.

[0079] Example 4

[0080] A method for controlling the diameter change of a CO2 variable diameter reactor is disclosed. Raw flue gas is delivered to the CO2 variable diameter reactor through a flue gas inlet. The raw flue gas entering the CO2 variable diameter reactor undergoes a CO removal reaction under the action of a catalyst, and the clean flue gas after CO removal is discharged from the flue gas outlet. The raw flue gas is sintering flue gas from a steel plant.

[0081] like Figure 2 As shown, the CO variable diameter reactor is configured as three layers of reactors along the direction from the flue gas inlet to the flue gas outlet, and the volume of each layer of reactors decreases layer by layer. Specifically, the cross-sectional area of each layer of reactors in the CO variable diameter reactor decreases layer by layer, and the height of each layer of reactors is the same.

[0082] Example 5

[0083] Example 4 was repeated, except that the CO variable diameter reactor was configured as a 6-layer reactor along the direction from the flue gas inlet to the flue gas outlet.

[0084] Example 6

[0085] Example 4 was repeated, except that the CO variable diameter reactor was configured as a 4-layer reactor along the direction from the flue gas inlet to the flue gas outlet.

[0086] Example 7

[0087] Example 4 was repeated except that the original flue gas was cement kiln tail gas.

[0088] Example 8

[0089] Example 4 was repeated except that the original flue gas was blast furnace tail gas.

[0090] Example 9

[0091] Example 4 was repeated, except that the method further included the step of calculating the diameter ratio of the CO variable diameter reactor, specifically comprising:

[0092] S1. Collect the working parameters of the original flue gas: detect the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, the mass concentration of CO in the original flue gas, and the mass concentration of O2 in the original flue gas.

[0093] S2. Based on the operating parameters of the original flue gas, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor.

[0094] S3. Based on the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, the ratio of the cross-sectional areas of the reactors in each layer is calculated to obtain the variable diameter ratio of the CO variable diameter reactor.

[0095] Example 10

[0096] like Figure 3 As shown, Example 4 is repeated, except that the method further includes the step of calculating the diameter ratio of the CO variable diameter reactor, specifically including:

[0097] S1. Collect the working parameters of the original flue gas: detect the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, the mass concentration of CO in the original flue gas, and the mass concentration of O2 in the original flue gas.

[0098] Wherein, step S1 is specifically as follows:

[0099] Collect the working parameters of the original flue gas: 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 variable diameter reactor. Among them, the flue gas flow detection device detects the original flue gas flow rate delivered to the CO variable diameter 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 original flue gas, which is recorded as C co =10000mg / m3 The O2 concentration detection device detects the mass concentration of O2 in the original flue gas, which is recorded as C O2 =2.985×10 5 mg / m 3 .

[0100] S2. Based on the operating parameters of the original flue gas, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor.

[0101] Wherein, step S2 is specifically as follows:

[0102] According to the operating parameters of the original flue gas, the catalyst deactivation model is established:

[0103]

[0104] There are also:

[0105]

[0106] C (i+1)coin =C icoout =C icoin ×(1-η i )…………(3).

[0107]

[0108] Where: Q i is the deactivation rate of the catalyst per unit volume in the i-th layer of the CO variable diameter reactor, m / h. R is the catalyst activity constant. The catalyst used is specifically a Pt / TiO2 noble metal catalyst, and R = 0.5. vi is the catalyst surface velocity in the i-th layer reactor, m / h. t is the service time of the catalyst in the CO variable diameter reactor, in years, and in this embodiment, t=0.1. icoin is the CO mass concentration at the inlet of the reactor at layer i, mg / m 3 . is the O2 mass concentration at the inlet of the i-th layer reactor, mg / m 3 b1 is the adjustment coefficient, b1 = 1 / 3600. V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, V = 1200000m 3 / h. A i is the cross-sectional area of the catalyst in the reactor layer i, m 2 . C (i+1)coin is the CO mass concentration at the inlet of the i+1 layer reactor, mg / m 3 . C icoout is the CO mass concentration at the outlet of the reactor at layer i, mg / m 3 η iis the CO catalytic oxidation efficiency in the i-th reactor. n is the number of reactor layers in the CO variable diameter 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 reactor, mg / m 3 . M co is the molar mass of CO, M co =28g / mol. M O2 is the molar mass of O2, M O2 =32g / mol.

[0109] Formulas (1)-(5) are combined to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor:

[0110] Deactivation rate of catalyst per unit volume in the first reactor:

[0111]

[0112] Where: Q1 is the deactivation rate of the catalyst per unit volume in the first reactor, m / h. A1 is the cross-sectional area of the catalyst in the first reactor, m 2 . C 1coin is the CO mass concentration at the inlet of the first layer reactor, C 1coin =C co =10000mg / m 3 . is the O2 mass concentration at the inlet of the first layer reactor,

[0113] The deactivation rate of catalyst per unit volume in the second reactor:

[0114]

[0115] in:

[0116] C 2coin =C 1coout =C 1coin ×(1-η1).

[0117]

[0118] Where: Q2 is the deactivation rate of the catalyst per unit volume in the second reactor, m / h. A2 is the cross-sectional area of the catalyst in the second reactor, m 2 . C 2coin is the CO mass concentration at the inlet of the second layer reactor, mg / m 3 . is the O2 mass concentration at the inlet of the second layer reactor, mg / m 3 .

[0119] The deactivation rate of catalyst per unit volume in the third reactor:

[0120]

[0121] in:

[0122] C 3coin =C 2coout =C 2coin ×(1-η2).

[0123]

[0124] Where: Q3 is the deactivation rate of the catalyst per unit volume in the third reactor, m / h. A3 is the cross-sectional area of the catalyst in the third reactor, m 2 . C 3coin is the CO mass concentration at the inlet of the third layer reactor, mg / m 3 . is the O2 mass concentration at the inlet of the third layer reactor, mg / m 3 .

[0125] S3. Based on the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, the ratio of the cross-sectional areas of the reactors in each layer is calculated to obtain the variable diameter ratio of the CO variable diameter reactor.

[0126] Wherein, step S3 is specifically as follows:

[0127] According to the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, we can get:

[0128] Q1=Q2=Q3…………(9).

[0129] The ratio of the cross-sectional areas of the reactors in each layer is calculated by the above formula as A1:A2:A3=100:55.49:10.67, that is, the diameter ratio of the CO variable diameter reactor is obtained, thereby realizing the diameter control of the CO variable diameter reactor.

[0130] Example 11

[0131] Repeat Example 10, except that the method further comprises:

[0132] S4. Based on the raw flue gas flow rate and space velocity ratio delivered to the CO variable diameter reactor per unit time, the total amount of catalyst required to treat the CO in the raw flue gas, i.e., the catalyst loading amount in the CO variable diameter reactor, is calculated. The height of each layer of reactors in the CO variable diameter reactor is then set, and the cross-sectional area ratio of each layer of reactors obtained by the above calculation is combined to obtain the cross-sectional area of each layer of reactors in the CO variable diameter reactor. That is,

[0133]

[0134] (A1+A2+A3)×h=V 催 …………(11).

[0135] Where: V 催 is the loading amount of catalyst in the CO variable diameter reactor, m 3 V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, V = 1200000m 3 / h. GHSV is the airspeed ratio, GHSV = 10000h -1 A1 is the cross-sectional area of the catalyst in the first layer of the reactor, m 2 A2 is the cross-sectional area of the catalyst in the second layer of the reactor, m 2 A3 is the cross-sectional area of the catalyst in the third layer of the reactor, m 2 . h is the set height of each layer of reactor, h = 1.16m.

[0136] Combining formulas (10) and (11), the cross-sectional area of each layer of the CO variable diameter reactor is A1 = 62.23m 2 A2 = 34.53m 2 、A3=6.64m 2 .

[0137] In this embodiment, the CO variable diameter reactor is designed based on the cross-sectional area, height, number of reactor layers and other data of each layer of reactors obtained above, so as to ensure that the clean flue gas obtained after the sintering flue gas passes through the CO variable diameter reactor meets the CO removal requirements. At the same time, the deactivation rate of the catalyst in the three layers of reactors in the CO variable diameter reactor is consistent, thereby avoiding the problem of catalyst waste during overall replacement.

Claims

1. A method for controlling the diameter change of a CO variable diameter reactor, characterized in that: The raw flue gas is transported to the CO reducer reactor through the flue gas inlet. The raw flue gas entering the CO reducer reactor undergoes CO removal reaction under the action of the catalyst, and the clean flue gas after CO removal is discharged from the flue gas outlet. Among them, along the direction from the flue gas inlet to the flue gas outlet, the CO reducer reactor is configured as a multi-layer reactor, and the volume of each layer of reactor decreases layer by layer.

2. The method according to claim 1, wherein: Along the direction from the flue gas inlet to the flue gas outlet, the cross-sectional area of each layer of reactors in the CO variable diameter reactor decreases layer by layer.

3. The method according to claim 2, wherein: In the CO variable diameter reactor, the heights of the reactors in each layer are the same.

4. The method according to any one of claims 1 to 3, characterized in that: Along the direction from the flue gas inlet to the flue gas outlet, the CO variable diameter reactor is arranged as an n-layer reactor, wherein: n is 2-8, preferably 3-6.

5. The method according to claim 3 or 4, characterized in that: The method also includes the step of calculating the diameter ratio of the CO variable diameter reactor, specifically comprising: S1. Collecting the working parameters of the original flue gas: detecting the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, the mass concentration of CO in the original flue gas, and the mass concentration of O2 in the original flue gas; S2. Based on the operating parameters of the original flue gas, a catalyst deactivation model is established to calculate the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor; S3. Based on the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, the ratio of the cross-sectional areas of the reactors in each layer is calculated to obtain the variable diameter ratio of the CO variable diameter reactor.

6. The method according to claim 5, characterized in that: Step S1 is specifically as follows: Collect the working parameters of the original flue gas: 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 variable diameter reactor; among them, the flue gas flow detection device detects the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, which is recorded as V, m 3 / h; CO concentration detection device detects the mass concentration of CO in the original flue gas, recorded as C co , mg / m 3 ; The O2 concentration detection device detects the mass concentration of O2 in the original flue gas, which is recorded as C O2 , mg / m 3 .

7. The method according to claim 6, characterized in that: Step S2 is specifically as follows: According to the operating parameters of the original flue gas, the 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 in the i-th layer reactor of the CO variable diameter reactor, m / h; R is the catalyst activity constant, and the value range of R is 0.2~2; A vi is the catalyst surface velocity in the i-th layer reactor, m / h; t is the service time of the catalyst in the CO variable diameter reactor, in years; C icoin is the CO mass concentration at the inlet of the reactor at layer i, mg / m 3 ; is the O2 mass concentration at the inlet of the i-th layer reactor, mg / m 3 ; b1 is the adjustment coefficient, and the value range of b1 is 1 / 2700~1 / 3700; V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, m 3 / h; A i is the cross-sectional area of the catalyst in the reactor layer i, m 2 ; C (i+1)coin is the CO mass concentration at the inlet of the i+1 layer reactor, mg / m 3 ; C icoout is the CO mass concentration at the outlet of the reactor at layer i, mg / m 3 ;η i is the CO catalytic oxidation efficiency in the i-th reactor; n is the number of reactor layers in the CO variable diameter reactor; b2 is the correction coefficient, and the value range of b2 is 0.3-0.5 m / h; is the O2 mass concentration at the inlet of the i+1 layer reactor, 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 in each layer of the CO variable diameter reactor: Deactivation rate of catalyst per unit volume in the first reactor: Where: Q1 is the deactivation rate of the catalyst per unit volume in the first layer of the reactor, m / h; A1 is the cross-sectional area of the catalyst in the first layer of the reactor, m 2 ; C 1coin is the CO mass concentration at the inlet of the first layer reactor, mg / m 3 ; is the O2 mass concentration at the inlet of the first layer reactor, mg / m 3 ; The deactivation rate of catalyst per unit volume in the second reactor: Where: Q2 is the deactivation rate of the catalyst per unit volume in the second layer reactor, m / h; A2 is the cross-sectional area of the catalyst in the second layer reactor, m 2 ; C 2coin is the CO mass concentration at the inlet of the second layer reactor, mg / m 3 ; is the O2 mass concentration at the inlet of the second layer reactor, mg / m 3 ; …… The deactivation rate of catalyst per unit volume in the nth layer reactor: Where: Q n A is the deactivation rate of the catalyst per unit volume in the nth layer reactor, m / h; n is the cross-sectional area of the catalyst in the nth layer reactor, m 2 ; C ncoin is the CO mass concentration at the inlet of the nth layer reactor, mg / m 3 ; is the O2 mass concentration at the inlet of the nth layer reactor, mg / m 3 .

8. The method according to claim 7, wherein: Step S3 is specifically as follows: According to the fact that the deactivation rate of the catalyst per unit volume in each layer of the CO variable diameter reactor is equal, we can get: Q1=Q2=……=Q n …………(9); Set the number of reactor layers n in the CO variable diameter reactor and calculate the ratio of the cross-sectional area of each layer of reactor A1:A2:...:A n , that is, the diameter ratio of the CO variable diameter reactor is obtained.

9. The method according to claim 8, characterized in that: The method further includes: S4. Calculate the total amount of catalyst required to treat CO in the original flue gas, i.e., the catalyst loading amount in the CO variable diameter reactor, based on the original flue gas flow rate and space velocity ratio delivered to the CO variable diameter reactor per unit time; then set the height of each layer of reactors in the CO variable diameter reactor, and calculate the cross-sectional area of each layer of reactors in the CO variable diameter reactor based on the ratio of the cross-sectional areas of the reactors in each layer; that is, <h2 style=";text-align:left;direction:ltr">(A1+A2+……+A<h2 style=";text-align:left;direction:ltr"> n <h2 style=";text-align:left;direction:ltr"> )×h=V<h2 style=";text-align:left;direction:ltr"> 催 <h2 style=";text-align:left;direction:ltr"> …………(11); Where: V 催 is the loading amount of catalyst in the CO variable diameter reactor, m 3 ; V is the original flue gas flow rate delivered to the CO variable diameter reactor per unit time, m 3 / h; GHSV is the airspeed ratio, h -1 ; A1 is the cross-sectional area of the catalyst in the first layer of the reactor, m 2 ; A2 is the cross-sectional area of the catalyst in the second layer reactor, m 2 ; A n is the cross-sectional area of the catalyst in the nth layer reactor, m 2 ; h is the height of each layer of reactor, m; Combining formulas (10) and (11), the cross-sectional areas A1, A2, ..., A of each layer of the CO variable diameter reactor are obtained. n .

10. The method according to any one of claims 1 to 9, characterized in that: The raw flue gas is flue gas containing CO; preferably, the raw flue gas is flue gas containing CO and O2; further preferably, the raw flue gas is one of sintering flue gas, cement kiln exhaust gas, and blast furnace exhaust gas.

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