The Preparation Of ZnFe₂O₄ Hot Coal Gas Desulfurizer Under Irradiation

The research and development of high temperature coal gas desulfurizer have changed gradually from mono-metal oxide into mixed-metal oxide, in which zinc ferrite sorbents have become the typical mixed-oxide desulfurizer, because of its high desulfurization precisior, high sulfur capacity and high reactivity.This thesis adopted coprecipitation under the ultrasonic radiation to get zinc ferrite precursors, then adopted calcinations under microwave irradiation to gain zinc ferrite of active components, and then treated zinc ferrite as active components, and used kaolin as structural additive to get hot gas desulfurizer. The thesis also characterized zinc ferrite desulfurizer by means of pore size distribution, pore volume, BET, XRD, SEM. And the thesis explored desulrization under the fixed bed reactor and simulated coal gas atmosphere. The conclusions are as follows:1. It is feasible to adopt corecipitation under the ultrasonic radiation and calcination under microwave irradiation to get zinc ferrite, and the ZnFe₂O₄ hot coal gas desulfurizer was prepared, which is excellent high temperature desulfurizer.2. In the process of coprecipitation under the ultrasonic radiation, components uniformity was gained, small particled zinc ferrite precursors formed spinel structrure under microwave irradiation. The zinc ferrite crystal grain gained was well distributed, whose range was from 40-60nm, and the crystal grain appeared global.3. To compare the zinc ferrite gained by microwave irradiation with the zinc ferrite gained by normal methods, the crystal phase of the former is more complete, and the crystal grain is well distributed. The result showed that the microwave irradiation promoted the formation of its configuration. It took 4 hour to gain the zinc ferrite by the normal methods. While it just took only an hour to gain it by microwave irradiation, which greatly shorted the sintering time.4. To compare the zinc ferrite gained by microwave irradiation with the zinc ferrite gained by normal methods, both of the specific surface area are to some extent identical, but the pore volume of the former was improved a lot ,up to 0.146cm³/g, which gave great help to improving desulfurization effect.5. The zinc ferrite gained by irradiation showed good and stable property in the process of desulfurization experiment. When the concentration of inlet is 3700ppm, that of outlet keeps about 14ppm, there is almost no fluctuation in 25 hours.6. The result showed the desulfurization efficiency of the excellent desulfurizer is 99.6% in the fixed reactor experiment, which is very high.