Study On Kinetic Performance With LDH On The Low Concentration SO₂ Removal And Its Amplifying Property

Through the preparation by co-deposition and activation of Layered Double Hydroxide桵g3Fe-type LDH, A kind of very active material for SO2 removal was obtained. In this thesis, it was studied in detail and systematically on the aspect of De-S02 performance of this kind of material. First of all, the thesis reviewed the research development in SO2 removal fields, summed up some common De-S02 methods and compared advantages and disadvantages of them. Secondly, the apparent kinetics of SO2 removal by Mg3Fe-type LDH desulfurizer was studied by using thermo gravimetric methods. Experiments showed that the reaction is of first order with respect to S02 concentration. In a temperature range of 400---?50C, the overall process was controlled by the surface reaction in the grain and came to the intrapellet controlled regime at the middle and last stage. The apparent kinetic behavior could be described by the Equivalent Grain Model. The activation energies of surface reaction and solid diffusion were determined as I .27)( 104J.moE1 and 6.844 X 1O~ J.moV?respectively. The reasons that there existed an optimum temperature were discussed. Thirdly, the kinetic performance of isothermal piston flow desulfurization bed was studied on basis of the Equivalent Grain Model which put forward suggested by the author that was used to describing apparent kinetics of desulfurization with Mg3Fe-type oxide particles. The representation of beak-through was given. After analysis of results obtained in a commercial scale de-sulfurizing bed of metal oxides, it was verified that the Equivalent Grain Model could be preferably used to describing the desulfurization process of complex metal oxides. Fourthly, durability of desulfurizers LDH was studied. Experiments showed that the sorbent had better reduction and regenerative properties and could be used as recircle sorbent. II 6 Fiftlily, Amplifying characteristics of catalytic oxidation on SO2 and re- generation of the LDH desulfurizer exploited on our own have been carried out in the fixed bed. The results indicate that the fresh sulfur capacity is the 1. 5OkgSO2 kg?Sorbent and the sulfur capacity of the material regenerated is in agreement with that of the laboratory test. Lastly, main conclusion was summarized and the application possibility was looked forward.