Preparation Of Zone Oxide Hot Coal Gas Desulfurizer By Solid-state Reaction Under Microwave

Coal gas desulfurization is the key technology which used in clean coal technology transformation and utilization, which is not only the important energy technology of national economic, social and environmental sustainable development, but also the crucial foundation for realizing China’s dream. According to characteristic of energy occurrence in our country, coal gasification will play an increasingly importance role in the national economy. Coal gas cleaning, however, is a critical process due to the corrosion of the equipment caused by hydrogen sulfide in the coal gases as well as the emission of air pollutants. Therefore, hydrogen sulfide must be reduced to below several ppmv. This paper focused on the preparation of ZnO desulfurizer by using microwave technology in order to find a reasonable and efficient preparation method.The following works are carried out in this paper:(1) The optimum modified conditions of raw semi-coke was700℃,2h. The specific surface area increased from15.178m2/g to336.766m2/g and pore volume increased from0.121cm3/g to0.310cm3/g. The temperature-rising characteristics of the precursor can be divided into two phase:rapid change phase (about6.5min) and slow change phase. In about9min, the temperature got to a stable temperature which was primarily determined by microwave power.(2) The effects of the heating rate of the precursor and binder on the behavior of mechanical strength were investigated under microwave irradiation. The optimum binder:ben shan clay. The optimum heating rate:the first stage:10℃/min from ambient temperature to380℃, the second stage:2℃/min from380to430℃, the third stage:10℃/min from430℃to target temperature and lasting for a period time. The mechanical strength of the sorbent prepared at500℃for30min was53.8N/cm.(3) The, effects of temperature, irradiation time, mass ratio and content of active component on the preparation of sorbent were studied. The optimum conditions were as follow:the temperature was500℃, the time was30min, the mass ratio was8:10, and the content active component was20%.(4) Compared with the desulfurizer prepared under microwave irradiation and conventional heating. The XRD analysis showed that the phase in desulfurizer prepared with different methods was ZnO, ZnS respectively before and after the reaction. The SEM analysis showed that the ZnO desulfurizer prepared under microwave irradiation had a uniform grain size crystal size that distributed homogeneously on the modified semi-coke. The BET analysis showed that the specific surface area, pore specific volume and pore size of sorbents decreased to some extent after sulfuration.The XPS analysis showed that the Zn-O binding energy desulfurizer prepared under microwave irradiation was less than that of prepared under conventional heating.(5) The break through curve and sulfur capacity of desulfurizer prepared by microwave irradiation and conventional heating were580min,485min and13.16%,10.89%, respectively. Suggesting that the desulfurizer prepared under microwave irradiation had better performance than that of prepared under the conventional heating.