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CN-121988344-A - Preparation process and system of plasma activated acid catalytic denitration heat storage body

CN121988344ACN 121988344 ACN121988344 ACN 121988344ACN-121988344-A

Abstract

The invention discloses a preparation process and a system of a plasma activated acid catalytic denitration heat accumulator. The method comprises the steps of sequentially carrying out ultrasonic cleaning, ultrasonic heating and activating with nitric acid solution, loading transition layer slurry, impregnating a multi-element catalytic active component suspension and spraying a nano composite suspension on a cordierite honeycomb ceramic carrier with an axial gradient pore structure, and carrying out staged drying and program temperature control calcination to obtain the high-performance denitration heat accumulator. The device comprises a material pretreatment and conveying module, an ultrasonic cleaning and activating module, a slurry preparation and mixing module, an impregnating and coating module, a drying and calcining module and a central control and monitoring unit, wherein the modules are integrated into a whole, and are linked through an automatic material transferring line to realize full-flow automatic and intelligent production. The invention enhances the adhesive force and uniformity of the coating by ultrasonic-assisted acid activation and gradient pore carrier design, and solves the problems of low activity, poor stability and unstable preparation efficiency of the existing denitration catalyst.

Inventors

  • Fan Lecheng
  • Ma Benyang
  • ZENG YIPING

Assignees

  • 浙江鲲秀科技有限公司

Dates

Publication Date
20260508
Application Date
20260317

Claims (10)

  1. 1. The preparation process of the plasma activated acid catalytic denitration heat accumulator is characterized by comprising the following steps of: S1, placing a gradient Kong Jin bluestone carrier into a clean container and fully soaking the carrier into deionized water, then utilizing ultrasonic cleaning with the frequency of 50kHz for 20 minutes to remove surface dust and loose impurities, and then placing cordierite into an environment of 120 ℃ for drying for 5 hours; S2, fully soaking the cordierite subjected to ultrasonic cleaning by the deionized water in the S1 in nitric acid solution, then placing the cordierite in an ultrasonic cleaning machine with the frequency of 50kHz, sealing by a cover, heating, carrying out ultrasonic soaking for 8 hours, and then placing the cordierite subjected to ultrasonic treatment Treating in plasma treating equipment at 300W and 40kHz for 10 min, and stoving cordierite at 450 deg.c for 2 hr to obtain activated gradient Kong Jin carrier; S3, putting nano gamma-alumina, silica sol and deionized water together into a ball milling tank, ball milling and mixing for 4 hours to form uniform and stable transition layer slurry, then immersing the activated gradient Kong Jin blue stone carrier obtained in S2 into the slurry, immersing for 10 minutes under the condition of vacuum degree of-0.095 MPa, and then drying the activated gradient Kong Jin blue stone carrier permeated with the slurry and baking in a muffle furnace to obtain an activated gradient Kong Jin blue stone carrier loaded with the slurry; s4, mixing vanadium pentoxide, tungsten trioxide, nickel dioxide, nano titanium dioxide, manganese dioxide and oxalic acid into 600ml of deionized water, and then placing the mixed system into a constant-temperature water bath to be stirred until a uniform suspension is formed; S5, fully mixing the activated gradient Kong Jin carrier obtained in the step S3 with the suspension obtained in the step S4, then placing the mixture in ultrasonic treatment with the frequency of 50kHz for 5 minutes, and then sequentially drying the cordierite carrier and baking the cordierite carrier in a muffle furnace to obtain the gradient Kong Jin carrier of the denitration catalytic layer; And S6, weighing nano cerium oxide, nano zirconium dioxide and polyethylene glycol, adding the mixture into absolute ethyl alcohol, ball-milling and dispersing for 2 hours to obtain uniform nano composite suspension, uniformly spraying the obtained suspension on the gradient Kong Jin of the denitration catalytic layer obtained in the step S5 by using a spray coating method, controlling the surface thickness of the carrier catalytic layer to be 10-20 mu m, and finally placing the product in a muffle furnace for calcination.
  2. 2. The process for preparing a plasma activated acid catalyzed denitration heat storage device according to claim 1, wherein the pore diameter of the inlet end unit of the gradient Kong Jin bluestone carrier in S1 is 1.8mm, the pore density is 300cpsi, the pore diameter of the outlet end unit is 1.2mm, and the pore density is 400cpsi.
  3. 3. The process for preparing the plasma activated acid-catalyzed denitration heat storage device according to claim 1, wherein the deionized and washed cordierite is soaked in a nitric acid solution with the concentration of 50 ℃ and 5wt% in S2 and soaked in an ultrasonic washing machine with the frequency of 50kHz for 8 hours.
  4. 4. The process for preparing a plasma activated acid-catalyzed denitration heat storage device according to claim 1, wherein the activation gradient Kong Jin of the infiltration slurry in S3 is placed in a muffle furnace for drying at 120 ℃ for 2 hours and at 450 ℃ for 3 hours respectively.
  5. 5. The process for preparing a plasma activated acid-catalyzed denitration heat accumulator according to claim 1, characterized in that in S4 the mixed system is placed in 70 ℃ warm water and stirred continuously for 2 hours at 1000 rpm.
  6. 6. The process for preparing the plasma activated acid-catalyzed denitration heat storage device according to claim 1, wherein in S5, the gradient cordierite subjected to ultrasonic treatment is dried for 1 hour at 120 ℃ and baked for 5 hours in a muffle furnace at 500 ℃.
  7. 7. The process for preparing the plasma activated acid-catalyzed denitration heat storage according to claim 1, wherein in S6, cordierite of which the suspension is sprayed is placed in a muffle furnace for drying at 80 ℃ for 30 minutes at 350 ℃ for 2 hours and for 8 hours at 600 ℃.
  8. 8. A system for preparing a plasma activated acid catalytic denitration heat storage system comprises a material pretreatment and conveying module, an ultrasonic cleaning and activating module, a slurry preparation and mixing module, a dipping and coating module, a drying and calcining module, a central control and monitoring unit and a plasma activating module, The material pretreatment and conveying module comprises an automatic feeding machine, a conveying belt and a visual detection system and is used for automatically feeding, conveying and sorting cordierite carriers; The ultrasonic cleaning and activating module comprises a multi-tank ultrasonic cleaning machine, an acid liquor circulation and temperature control system, an automatic capping and sealing device, a deionized water spray cleaning unit and a hot air drying box, and is used for ultrasonic cleaning and acid activation; The slurry preparation and mixing module comprises a ball mill, a vacuum impregnation tank, a constant-temperature water bath stirring system and an automatic feeding system, and is used for preparing slurry and suspension; The dipping and coating module comprises a vacuum dipping workbench, an ultrasonic dispersion tank and an automatic spray coater and is used for dipping, mixing and spraying; the drying and calcining module comprises a multi-section oven and a program temperature control muffle furnace and is used for drying, baking and calcining; the plasma activation module comprises A plasma processing apparatus for plasma activation; the central control and monitoring unit is in communication connection with each process module and is used for uniformly setting, monitoring and adjusting ultrasonic frequency, temperature, vacuum degree, dipping time, stirring rotating speed and calcination program.
  9. 9. The system for preparing the plasma activated acid catalytic denitration heat storage process according to claim 8, wherein each process module of the system is linked through an automatic material transfer line and an integrated control bus, the automatic material transfer line comprises a corrosion-resistant conveyor belt, a sealing pipeline and a mechanical arm with a clamp, the mechanical arm is used for directionally and continuously conveying carriers and slurry among the modules, the integrated control bus is a distributed I/O system based on industrial Ethernet, and synchronous acquisition and real-time regulation and control of process parameters of all modules by a central control unit are realized.
  10. 10. The system for preparing the plasma activated acid catalytic denitration heat storage process according to claim 8, wherein the connection mode of the ultrasonic cleaning and acid activation module and the adjacent module specifically comprises the steps that an upstream raw material storage module is connected with a to-be-treated carrier through a dustproof sealing conveyor belt, an internal acid liquor circulation temperature control subsystem is connected with a heat source of a public engineering system through a heat exchange pipeline to maintain a constant temperature of 50 ℃, a downstream vacuum impregnation module is connected with the to-be-treated carrier through a capped acid-resistant chain plate conveyor, and the dried activated carrier is conveyed, and the conveying process is carried out under the protection of a micro negative pressure inert atmosphere.

Description

Preparation process and system of plasma activated acid catalytic denitration heat storage body Technical Field The invention relates to the field of catalytic reduction denitration catalyst preparation and system integration, and relates to a preparation process and a system of a plasma activated acid catalytic denitration heat accumulator. Background In the field of industrial flue gas treatment, a selective catalytic reduction denitration technology has become a mainstream technology for controlling emission of nitrogen oxides in industrial processes such as coal-fired power plants, steel smelting, cement production and the like by virtue of the high-efficiency and reliable characteristics of the selective catalytic reduction denitration technology. The core is that a catalyst is used for promoting the reaction of ammonia gas and NOx to generate harmless nitrogen gas and water in a specific temperature window. However, as environmental standards become increasingly stringent and industrial conditions tend to be complex, existing commercial SCR catalyst systems expose several key technical drawbacks in practical long-term operation, severely restricting their denitration efficiency, operating life and economy. First, there are significant limitations to the activity and temperature adaptability of the catalyst. The activity of the traditional vanadium tungsten titanium catalyst widely used at present is highly dependent on temperature. In the low temperature range below 300 ℃, the catalyst has insufficient adsorption and activation capability on reactants, which leads to a sharp drop in denitration efficiency, while when the flue gas temperature is continuously higher than 400 ℃, the active components V2O5 are easy to migrate, agglomerate and even sinter, so that the number of active sites is reduced, and the titanium dioxide carrier is converted from high-activity anatase phase to inert rutile phase, which leads to irreversible deactivation of the catalyst. The narrow effective temperature window is difficult to adapt to frequent and severe flue gas temperature fluctuation of an actual industrial kiln caused by load change, and particularly under transient working conditions such as start-up and shutdown, load adjustment and the like, a denitration system often cannot stably operate, and becomes a technical bottleneck for realizing ultra-low emission and stable standard reaching. Secondly, the mechanical strength and long-term thermochemical stability of the catalyst coating are inadequate. The combination between the active component of the catalyst coating prepared by the prior art and carriers such as cordierite, metal honeycomb and the like is mostly dependent on physical adsorption and simple chemical bonding, and the bonding force is generally weaker. Under the long-term flushing of high-speed dust-containing flue gas, the coating is easy to abrade, and under the severe thermal shock caused by starting and stopping the furnace or sudden load change, the coating is easy to crack and even peel off in a large area due to the fact that the thermal expansion coefficients of the carrier and the coating material are not matched. More seriously, sulfur dioxide and water vapor commonly existing in the flue gas can react with active centers to generate substances such as sulfate and the like, block the pore channels of the catalyst, cover active sites and cause the catalyst to be poisoned and deactivated. The combined action of coating shedding and chemical poisoning not only greatly shortens the service life of the catalyst and increases the replacement frequency and the disposal cost, but also can cause the increase of ammonia escape amount due to the loss of local activity, thereby causing the interlocking problems of downstream air preheater blockage, secondary pollutant formation and the like. Furthermore, the automation, refinement and standardization of the existing catalyst preparation process are in need of improvement. In the current industrial production, the catalyst loading process and the subsequent key processes of drying, calcining and the like still depend on manual experience and batch operation to a great extent. The core technological parameters such as slurry concentration, dipping time, drying curve, calcining temperature, atmosphere and the like are controlled roughly, and the fluctuation is large. The production mode directly leads to the obvious difference of the catalyst products in the same batch or even different batches in the aspects of active component loading capacity, distribution uniformity, crystal phase structure and final performance, and uniformity and repeatability of product quality cannot be ensured. In addition, the traditional process has high energy consumption, low material utilization rate and long production period, and is difficult to meet the increasing large-scale continuous production demands of the market on high-performance and low-cost catalysts. Therefor