Preparation Of Combustion Catalyst β-Cu Ultrafine Powders In Impinging Steam-Rotating Packed Bed

It had been summarized about the developmental survey and actuality, applications andpreparing methods of ultrafine combustion catalyst, at the same time, it had been summarizedanalyzed that the developmental actuality and technical characteristics of processintensification technology in the paper. Owing to the extraordinary performance, combustioncatalyst ultrafine powder have the huge application potential in catalyst material. Thereforepreparation and application of combustion catalyst ultrafine is getting more and moreattention. But in precipitation process, the traditional reactor can't satisfy the liquid to respondmutually and quickly to the minxing request, is big with a degree the powder that make tohave, the size distribution of the precipitating particles as main characteristic. Aim at theexistent shortages of traditional reactor, the goal of thesis is to develop a process easier forapplication in industry base on process intensification nature of Impinging Steam-RotatingPacked Bed, with CuSO4 solution as the basic raw material and 2,4-Dihyoxybenzoicacid asthe precipitant.Primarily, the adoption crystal theories to the liquid-liquid system had the process of theultrafine particles to carry on the theories analysis, and it is the first time that the inductiontime, and micromixing time is studied by in the synthesis process ofβ-Cu ultrafine particlesvia reaction precipitation, the complex reaction is so fast that the induction time is only 38s.To obtain ultrafine particles with narrow size distribution, therefore, one should do as much aspossible to meet the requirement of homogeneous mixing on the molecular scale. Pass tocontrast the experiment detection, the induce time of the precipitate reaction in IS-RPB canshorten to the 3.77s.In order to detect micromixing in IS-RPB, the fast competitive parallelreaction of 1-and 2-naphthol with diazotized sulfanilic acid was chosen. Other reactionswhich are commonly used in literature were too slow for the investigation. Under the sameoperation condition, IS-RPB to XS is IS reactor and RPB reactor to XS of 200% much,micromixing with the function better, its micromixing time as 1.81 ms.These results show thatImpinging Steam-Rotating Packed Bed can quicken the reaction process and shorten theinduction time ,also provide the dependable theories foundation for preparing ultrafinepowder.Secondly, in the present study of Impinging Steam-Rotating Packed Bed (IS-RPB) withperfect micromixing nature is used for preparation of by precipitation. In this paper, ultrafinepowders were prepared by the precipitation technique using 2,4-Dihyoxybenzoicacid andCuSO4·5H20 as raw material. Efects of the variations in four levels of concentration of rawmaterial, temperature, pH, rotational speed and impact flow was studied by simply orthogonaltesting design. According to the layout of four levels with five factors,sixteen differentexperiments were done for the size of particle. An analysis of the experimental data show thatimpact flow are the main factor for the size of particle, and the efect on size of particles isimpact flow > rotational speed > concentration of raw material > temperature > pH.Consequently, The optimum synthesis conditions were determined, impact flow is 100L·h-1,rotational speed is 1000rpm, concentration of raw material is 1.2mol·L-1, formation of β-Cuat pH=8 and temperature is 60℃. In these conditions, 98nm spindle particles can be obtained.Finally disperse and agglomeration is an important problem not be ignored for thepreparation of ultrafine particles. The reasons causing agglomeration in the preparationprocess of ultrafine particles in solutions and desiccation process are analyzed. The interactionmechanism of several agglomeration and their effects were explained. The anti-agglomerationmeasures in non-aqueous phase or surface modification which should be taken are discussed.It was found that adding surface modifier PEG400 are helpful to control agglomeration of β-Cu particles. The product was characterized by TEM,XRD,BET and Laser Size Analysis(LSA) method and so on. The prepared spindle particles with size range from 0.12μm to 5μm can be obtained. The average particle size of the product is 610nm and specific surface areais 11.6265 m2·g-1.In summary, these processes in fact describe a generic approach to prepare combustioncatalyst ultrafine powder. In addition, these processes will have wide applications in the light ofthe characters of the methods.