Preparation And Properties Of Powder Denitration Agent Based On Microcapsule Additives

In this paper,a method for preparing catalytic material microcapsules based on double-regulation of core-shell particle size was proposed.Based on this,a powder denitration agent is prepared.The denitration agent could efficiently remove flue gas in a wide temperature window of 600~900°C.Nitrogen oxides.The catalytic material was potassium permanganate,which was coated by the melt-dispersion condensation microcapsule technology.The particle size and the nuclear material were double-regulated by pneumatic emulsification and cyclone classification,and a micro-encapsulation experimental device was constructed.The effects of different preparation methods,average flow rate,nuclear particle size and other process parameters on the performance of microcapsule catalytic materials were investigated.The experimental results show that the gas flow rate is 1.12 m/s,the nuclear particle size was 15.4?m,and the core-shell material mass ratio was 1:3.5.The microcapsule catalytic material prepared under the microencapsulation condition with a hydrophilic-lipophilic balance value of 10 had a particle diameter of 180?m and a coating ratio of 91%.SEM characterization of the surface morphology of the microcapsules revealed that the microcapsules were multi-core coated with the catalytic material as the core-beeswax as the shell;the microscopic crystalline structure and component activity of the catalytic material were not changed by XRD pattern analysis.By FT-IR spectrum comparison analysis,the microcapsule catalytic material was coated by chemical bonding interaction instead of simple physical adsorption;by UV and TG analysis,the microcapsule catalytic material has a particle size of 180?m.Better sustained release performance,easier release;OM observation of microcapsule preparation process shows that the microencapsulation process first melts the shell material into a molten state,and adds nuclear material to form a uniform shell core dispersion system.After cooling the shell material a film was formed around the core material.In this paper,a powder denitrification agent was prepared,which was prepared by mixing microcapsule catalytic materials,ammonium chloride,desiccant and combustion improver in a certain proportion.The performance of fluidized catalytic denitrification catalyst for nitrogen oxide removal was investigated in a fluid catalytic experiment device.And determine the optimal process parameters:under the experimental conditions of simulating flue gas flow of 4.8 m~3/h,reaction temperature of 600-900°C,ammonia-nitrogen molar ratio of 1.3:1,and microcapsule catalytic material mass fraction of 1.6%,the denitration efficiency could be More than 92%.The results show that the preparation of powder denitrification agent based on double-regulated microcapsules with core-shell particle size could adjust the average particle size and coverage of microcapsules by changing the process parameters,which could further improve the release of microcapsule catalytic materials and improve denitrification.Efficiency is expected to solve the technical problems that are not applicable to the existing denitration technology faced by small and medium-sized coal-fired boilers in China.