Method for on-line regeneration of CO catalyst
By introducing electric heating materials and heat tracing devices into the CO catalyst, the online regeneration of the CO catalyst is realized, and the problems of catalysts are easily poisoned and consumed are solved, operating costs and investment are reduced, and construction time is short.
Patent Information
- Application Number
- CN202510001281.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-03-28
AI Technical Summary
The prior art is difficult to realize the online regeneration of the CO catalyst of the sintering machine, resulting in the catalyst being easily poisoned, consumed large amounts and cannot be regenerated online.
The electro-heating material is synthesized into the catalyst block during the production of the CO catalyst, and the CO catalyst block with a heat tracing or resistance heating device is made, and the flue gas of the sintering machine is regenerated online during the regeneration process. The sulfate is decomposed at high temperature to generate sulfur dioxide and metal oxides, and the catalyst activity is restored.
The online regeneration of CO catalysts is achieved, operating costs are reduced, investment is small and land is not occupied, construction time is short, and there is no need to change the conventional operation mode of the kiln.
Smart Images
Figure CN119702089A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of combustion flue gas emission reduction, and in particular to a method for online regeneration of a CO catalyst. Background Art
[0002] Sulfur poisoning is the main cause of deactivation of sintering machine CO catalysts. Sulfur poisoning causes the active sites of the catalyst to be occupied by sulfides, making it inactive. For CO catalysts, sulfur poisoning is usually caused by trace amounts of sulfides (such as H2S, COS, etc.) in the feed gas. These sulfides bind to the active sites on the catalyst surface under reaction conditions to form stable sulfides, which hinder the adsorption and reaction of CO molecules. In order to regenerate sulfur-poisoned CO catalysts, the following steps are usually required: Removal of surface sulfides: The sulfides on the catalyst surface are converted into volatile substances (such as H2S) and removed by high temperature treatment or chemical reduction. For example, the catalyst can be heated in a reducing atmosphere (such as H2) to reduce the sulfides to H2S and release them. Redispersion treatment: If sulfur poisoning causes the precious metal particles to aggregate, the activity of the catalyst can be restored by redispersion treatment. This usually involves redispersing the precious metal on the support surface under appropriate conditions. For example, the catalyst can be treated with an aqueous solution of a Bronsted acid compound to help disperse the precious metal particles. Acid treatment: For some types of catalysts, acid treatment can help remove sulfides and restore activity. For example, the catalyst can be treated with a dilute acid solution to remove surface sulfides. Oxidation treatment: In some cases, oxidation treatment can help restore catalyst activity. For example, the catalyst can be treated with oxygen or air at an appropriate temperature to oxidize surface sulfides and restore activity. It should be noted that the specific conditions and methods of the regeneration process may vary depending on the type and composition of the catalyst.
[0003] The sulfur poisoning that causes the deactivation of sintering machine CO catalysts and dry SCR catalysts is mainly caused by high concentrations of SO2 and SO3 in the flue gas, which react with the active sites on the catalyst surface to form sulfate precipitates. SO2 will oxidize the active metals on the catalyst surface to form sulfates, mask the active sites, reduce the specific surface area and porosity of the catalyst, reduce the denitrification efficiency, and increase the pressure drop. SO2 poisoning will significantly reduce the activity of the catalyst, especially under low temperature conditions. In addition to sulfate deposition poisoning, there are other SO2 poisoning mechanisms such as competitive adsorption and acid corrosion.
[0004] The regeneration methods of SO2 poisoned catalysts mainly include: 1. Hydrothermal regeneration: Hydrothermal regeneration uses high-temperature steam to dissolve and remove sulfate precipitates on the catalyst surface. The regeneration temperature is generally 400-600°C and the regeneration time is 1-2 hours.
[0005] 2. Alkali washing regeneration: Alkali washing regeneration is to use alkaline solution (such as NaOH or NH4OH) to dissolve and remove sulfate precipitates on the catalyst surface. The regeneration temperature is generally room temperature to 60°C, and the regeneration time is 1-2 hours.
[0006] 3. Oxidation regeneration: Oxidation regeneration is to use an oxidant (such as O2 or air) to oxidize the sulfate precipitate on the catalyst surface at high temperature, converting it into volatile gases (such as SO2 or SO3) for removal. The oxidation regeneration temperature is generally 300-500℃, and the regeneration time is 1-2 hours.
[0007] 4. Ion exchange regeneration: Ion exchange regeneration is to use ion exchange resin to replace sulfate ions on the catalyst surface and replace them with other ions (such as Cl - or NO3 - ) to replace. After regeneration is completed, the ion exchange resin needs to be regenerated.
[0008] All of the above regeneration methods require the removal of the catalyst for remote regeneration, and online regeneration is not possible. Regular maintenance is also a key measure to prevent SO2 poisoning, including regular monitoring of the denitrification system operation status, timely removal of dust and sediment on the catalyst surface, and avoiding long-term exposure of the catalyst to a high concentration of SO2. Summary of the invention
[0009] 1. Technical issues to be resolved Aiming at the deficiency that the sulfur poisoning regeneration method of the deactivated CO catalyst of the sintering machine is difficult to achieve online regeneration, the present invention provides a method for online regeneration of the CO catalyst, which solves the problems of easy poisoning of the CO catalyst, large catalyst consumption, and inability to regenerate the catalyst online.
[0010] (II) Technical solution To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for online regeneration of a CO catalyst comprises the following steps: S1. When producing CO catalyst, the electric heating material is synthesized into the CO catalyst block to make a CO catalyst block with a tracing or resistance heating device; During the regeneration process, the flue gas from the sintering machine is preheated by the GGH1 system, and then enters the catalyst box with a heating device. When the flue gas temperature rises to more than 800°C, the poisoned and ineffective catalyst body decomposes, and the sulfate in it quickly generates sulfur dioxide and metal oxides. The sulfur dioxide is discharged into the chimney, and the metal oxides become a catalyst for CO removal. The heated flue gas enters the CO catalytic tower to complete the removal reaction. The main reaction process under the action of the catalyst is: 2CO+O2=2CO2 2NO+2CO=N2+2CO2.
[0011] The main reaction process of its regeneration is: SO4 2+ +2CO=SO2+CO2, SO4 2+ =SO2+2O 2- ; S3, the waste heat from heating is recovered by the GGH2 system after the catalyst tower, and then returns to the front-end GGH1 system for heat exchange and is used to heat the inlet flue gas.
[0012] Preferably, the DC voltage used by the electric heating device in S1 can be any one of 12V, 24V, and 36V, and is provided with a power regulating device.
[0013] Preferably, the CO catalyst block electric heating device synthesized into the heating device in S1 is any one of a mesh, a strip, and a block honeycomb structure with a resistance value, and insulated electrodes are installed at both ends of the inlet and outlet of the catalyst box, and the electrode material is selected from graphite or stainless steel.
[0014] Preferably, the S2 is equipped with a catalyst tower temperature monitoring device and an online regeneration electronic control system. When the flue gas temperature reaches greater than 800°C, it should be kept warm. When the carbon monoxide removal efficiency in the CEMS is stably restored to greater than 98% of the original value, the regeneration can be stopped.
[0015] Preferably, the metal oxide generated by the decomposition reaction in S2 continues to adhere to the CO catalyst.
[0016] Preferably, the waste heat from the flue gas heating in S3 is recovered by GGH2, and the heat is used by GGH1 to heat the regenerated flue gas.
[0017] (III) Beneficial effects The present invention provides a method for online regeneration of CO catalyst. It has the following beneficial effects: 1. The method for online regeneration of CO catalyst has low operating cost and can realize long-term regular maintenance of CO catalyst.
[0018] 2. The method of online regeneration of CO catalyst requires little investment, does not occupy additional land, directly replaces the original block CO catalyst, and has a short construction time. The investment is saved by about 30%.
[0019] 3. The method of online regeneration of CO catalyst is simple, reliable and easy to automate.
[0020] 4. The method of online regeneration of CO catalyst does not require major changes to the kiln flue gas emission system, does not require changes to the conventional operation mode of the kiln, and has basically no adverse effects on the main operating parameters of the kiln. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 is a process flow chart; Figure 2 This is the CO catalyst box diagram. DETAILED DESCRIPTION
[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] Embodiment 1: like Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a method for online regeneration of a CO catalyst, comprising the following steps: S1. During the production of CO catalyst, the electric heating material is synthesized into the CO catalyst block to make a CO catalyst block with a tracing or resistance heating device. The DC voltage used by the electric heating device in S1 can be 12V, and it is equipped with a power regulating device. The electric heating device of the CO catalyst block synthesized into the heating device in S1 is mesh-shaped, and insulated electrodes are installed at both ends of the inlet and outlet of the catalyst box, and the electrode material is graphite.
[0024] S2. During the regeneration process, the flue gas from the sintering machine is preheated by the heat exchange of the GGH1 system, and the flue gas enters the catalyst box with a heating device. When the flue gas temperature rises to above 800°C, the poisoned and ineffective catalyst body decomposes, and the sulfate in it quickly generates sulfur dioxide and metal oxides. The sulfur dioxide enters the chimney and is discharged, and the metal oxides become a catalyst for CO removal and do not need to be cleaned; The heated flue gas enters the CO catalytic tower to complete the removal reaction. The main reaction process under the action of the catalyst is: 2CO+O2=2CO2 2NO+2CO=N2+2CO2.
[0025] The main reaction process of its regeneration is: SO4 2+ +2CO=SO2+CO2, SO4 2+ =SO2+2O 2- .
[0026] S2 is equipped with a catalyst tower temperature monitoring device and an online regeneration electronic control system. When the flue gas temperature reaches more than 800°C, it should be kept warm. When the carbon monoxide removal efficiency in CEMS is stably restored to more than 98% of the original value, regeneration can be stopped. The metal oxides generated by the decomposition reaction in S2 continue to attach to the CO catalyst.
[0027] The waste heat from heating in S3 is recovered by the GGH2 system behind the catalyst tower, and then returned to the front-end GGH1 system for heat exchange to heat the inlet flue gas. The waste heat from the flue gas heating in S3 is recovered by GGH2, and GGH1 uses the heat to heat the regenerated flue gas.
[0028] Embodiment 2 like Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a method for online regeneration of a CO catalyst, comprising the following steps: S1. During the production of CO catalyst, the electric heating material is synthesized into the CO catalyst block to produce a CO catalyst block with a tracing or resistance heating device. The DC voltage used by the electric heating device in S1 can be 24V, and it is equipped with a power regulating device. The electric heating device of the CO catalyst block synthesized into the heating device in S1 is strip-shaped, and insulated electrodes are installed at both ends of the inlet and outlet of the catalyst box, and the electrode material is selected to be stainless steel.
[0029] S2. During the regeneration process, the flue gas from the sintering machine is preheated by the heat exchange of the GGH1 system, and the flue gas enters the catalyst box with a heating device. When the flue gas temperature rises to above 800°C, the poisoned and ineffective catalyst body decomposes, and the sulfate in it quickly generates sulfur dioxide and metal oxides. The sulfur dioxide enters the chimney and is discharged, and the metal oxides become a catalyst for CO removal and do not need to be cleaned; The heated flue gas enters the CO catalytic tower to complete the removal reaction. The main reaction process under the action of the catalyst is: 2CO+O2=2CO2 2NO+2CO=N2+2CO2.
[0030] The main reaction process of its regeneration is: SO4 2+ +2CO=SO2+CO2, SO4 2+ =SO2+2O 2- .
[0031] S2 is equipped with a catalyst tower temperature monitoring device and an online regeneration electronic control system. When the flue gas temperature reaches more than 800°C, it should be kept warm. When the carbon monoxide removal efficiency in CEMS is stably restored to more than 98% of the original value, regeneration can be stopped. The metal oxides generated by the decomposition reaction in S2 continue to attach to the CO catalyst.
[0032] The waste heat from heating in S3 is recovered by the GGH2 system behind the catalyst tower, and then returned to the front-end GGH1 system for heat exchange to heat the inlet flue gas. The waste heat from the flue gas heating in S3 is recovered by GGH2, and GGH1 uses the heat to heat the regenerated flue gas.
[0033] Embodiment 3 like Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a method for online regeneration of a CO catalyst, comprising the following steps: S1. During the production of CO catalyst, the electric heating material is synthesized into the CO catalyst block to produce a CO catalyst block with a tracing or resistance heating device. The DC voltage used by the electric heating device in S1 can be 36V, and it is equipped with a power regulating device. The electric heating device of the CO catalyst block synthesized into the heating device in S1 is similar to a block honeycomb structure with a resistance value. Insulated electrodes are installed at both ends of the inlet and outlet of the catalyst box, and the electrode material is graphite.
[0034] S2. During the regeneration process, the flue gas from the sintering machine is preheated by the heat exchange of the GGH1 system, and the flue gas enters the catalyst box with a heating device. When the flue gas temperature rises to above 800°C, the poisoned and ineffective catalyst body decomposes, and the sulfate in it quickly generates sulfur dioxide and metal oxides. The sulfur dioxide enters the chimney and is discharged, and the metal oxides become a catalyst for CO removal and do not need to be cleaned; The heated flue gas enters the CO catalytic tower to complete the removal reaction. The main reaction process under the action of the catalyst is: 2CO+O2=2CO2 2NO+2CO=N2+2CO2.
[0035] The main reaction process of its regeneration is: SO4 2+ +2CO=SO2+CO2, SO4 2+ =SO2+2O 2- .
[0036] S2 is equipped with a catalyst tower temperature monitoring device and an online regeneration electronic control system. When the flue gas temperature reaches more than 800°C, it should be kept warm. When the carbon monoxide removal efficiency in CEMS is stably restored to more than 98% of the original value, regeneration can be stopped. The metal oxides generated by the decomposition reaction in S2 continue to attach to the CO catalyst.
[0037] The waste heat from heating in S3 is recovered by the GGH2 system behind the catalyst tower, and then returned to the front-end GGH1 system for heat exchange to heat the inlet flue gas. The waste heat from the flue gas heating in S3 is recovered by GGH2, and GGH1 uses the heat to heat the regenerated flue gas.
[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for online regeneration of a CO catalyst, characterized in that: The following steps are involved: S1. When producing CO catalyst, the electric heating material is synthesized into the CO catalyst block to make a CO catalyst block with a tracing or resistance heating device; During the regeneration process, the flue gas from the sintering machine is preheated by the GGH1 system, and then enters the catalyst box with a heating device. When the flue gas temperature rises to more than 800°C, the poisoned and ineffective catalyst body decomposes, and the sulfate in it quickly generates sulfur dioxide and metal oxides. The sulfur dioxide is discharged into the chimney, and the metal oxides become a catalyst for CO removal. The heated flue gas enters the CO catalytic tower to complete the removal reaction. The main reaction process under the action of the catalyst is: 2CO+O2=2CO2 2NO+2CO=N2+2CO2.
2. The main reaction process of its regeneration is: <h2 style=";text-align:left;direction:ltr">SO4<h2 style=";text-align:left;direction:ltr"> 2+ <h2 style=";text-align:left;direction:ltr"> +2CO=SO2+CO2, <h2 style=";text-align:left;direction:ltr">SO4<h2 style=";text-align:left;direction:ltr"> 2+ <h2 style=";text-align:left;direction:ltr"> =SO2+2O<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> ; S3, the waste heat from heating is recovered by the GGH2 system after the catalyst tower, and then returns to the front-end GGH1 system for heat exchange and is used to heat the inlet flue gas.
3. The method for online regeneration of CO catalyst according to claim 1, characterized in that: The DC voltage used by the electric heating device in S1 can be any one of 12V, 24V, and 36V, and is equipped with a power regulating device.
4. The method for online regeneration of CO catalyst according to claim 1, characterized in that: The CO catalyst block electric heating device synthesized into the heating device in S1 is any one of a mesh, a strip, or a block honeycomb structure with a resistance value. Insulated electrodes are installed at both ends of the catalyst box inlet and outlet, and the electrode material is graphite or stainless steel.
5. The method for online regeneration of CO catalyst according to claim 1, characterized in that: The S2 is equipped with a catalyst tower temperature monitoring device and an online regeneration electronic control system. When the flue gas temperature reaches more than 800°C, it should be kept warm. When the carbon monoxide removal efficiency in the CEMS is stably restored to more than 98% of the original value, the regeneration can be stopped.
6. The method for online regeneration of CO catalyst according to claim 1, characterized in that: The metal oxides generated by the decomposition reaction in S2 continue to adhere to the CO catalyst.
7. The method for online regeneration of CO catalyst according to claim 1, characterized in that: The waste heat from the flue gas heating in S3 is recovered by GGH2, and the heat is used by GGH1 to heat the regenerated flue gas.