Catalyst Formation And Its Effect On Adsorption/Reduction Of NO_x Reduction Characteristics

The NOx reduction by CO process can overcome a series of problems such as ammonia escape caused by ammonia SCR,air preheater and downstream pipeline blockage,etc.At the same time,it can realize the joint removal of CO generated by incomplete combustion in flue gas,and has been widely concerned by many domestic and foreign scholars.In order to eliminate the negative effects of flue gas carrying O2 during the NOx reduction process of the CO method,a new rotary reactor is used to separate the adsorption and reduction of the NOx reduction reaction into two zones for NO removal.The research group conducted a series of studies on the CO NOx reduction catalyst in the early stage,and selected copper-cerium composite metal oxide catalysts with good low-temperature NOx reduction activity.On this basis,this article aims at the industrial application of catalysts for NOx reduction by CO,and combines the characteristics of rotary reactors to conduct catalyst molding research.Research on active ingredient loading and NOx reduction performance by coating honeycomb carrier molding.The research shows that when the coating solution of the same composition is applied,the number of coatings affects the effect of small-cell honeycomb NOx reduction,and the number of coatings is less than the optimal number of 4 The NOx reduction activity increases with the number of coatings,and the NOx reduction activity decreases slightly when the optimal number is exceeded 4 times.The acid treatment and alkali treatment of the substrate pretreatment before coating will affect the NOx reduction activity of the catalyst,30%nitric acid treatment After that,the NOx reduction activity is obviously improved;the calcination temperature and time will have an effect on the coating strength and sintering structure,and the best comprehensive effect will be obtained by calcining at 500? for 2 hours;by changing the type and amount of binder in the coating solution,Aluminum sol has little effect on the NOx reduction activity of the coated active material,and water glass has a greater influence on the coated active material.Finally,the decoupling experiment of the coated catalyst is carried out.The dynamic NOx reduction activity at 250? is high.As the temperature increases,the dynamic NOx reduction activity does not increase significantly,which is mainly due to the double effect of weakened adsorption and enhanced reducing activity.Through the research on the active components and NOx reduction performance of the impregnated honeycomb carrier molding method,the results show that the acid-treated cordierite honeycomb does not significantly improve the NOx reduction performance of the catalyst after impregnation,and after adding Al2O3 coating,the NOx reduction activity is greatly improved;the impregnating precursor body fluid When the concentration is increased,the NOx reduction activity can be increased by appropriately increasing the loading of active ingredients;the space velocity is lower in the space velocity range of 1000-3000h-1,and the catalytic activity is not significantly reduced;the concentration of the reducing agent CO during the NOx reduction process can be increased NO conversion rate,and the greater the concentration of NO in the flue gas,the smaller the reduction in catalyst conversion rate,indicating that the impregnated shaped catalyst is more adaptable to changes in NO concentrationThrough the preparation of extrusion molding catalyst and the research on the NOx reduction performance after molding,through the comparative screening of TiO2 and ZrO2 matrix materials,the selection of binder water glass and polypropylene ammonia,the addition of strength agent pseudo-boehmite,pore-forming agent hydroxyethyl The base cellulose and glycerin are squeezing aids,which are mixed with the active ingredients of the catalyst and kneaded to form a plastic embryo body,which is extruded,dried and calcined to prepare an extruded catalyst.Through the analysis of the NOx reduction performance of the catalysts prepared by extrusion molding,the NOx reduction efficiency is slightly reduced and the mechanical strength is greatly improved after adding the reinforcing agent;the active ingredient addition amount exceeds 25%in order to better exert the NOx reduction activity;the O2 content in the flue gas As a result,the NOx reduction activity increases with the increase of oxygen content,the NO conversion rate drops significantly,but the catalyst adsorption performance gradually improves.The shaped catalyst is selected for the establishment of the adsorption model and the fitting of the reduction reaction rate.Through the establishment of the model and the simulation fitting of the key parameters affecting the adsorption and reduction performance,it provides guidance for the design of the experimental direction and the setting of the reaction conditions.