71.N_2O分解に対するCaOの細孔構造の影響(石炭利用における科学と工学の融合)

抄録

The limestone is used as desulfurization sorbents in fluidized bed combustors (FBC). This material decomposes into CaO, which then reacts with SO_2 during desulfulization process. The CaO also acts as a catalyst for N_2O decomposition in the combustor. However, the activity of CaO catalyst during N_2O decomposition process decreases with sulfation of the CaO due to pore plugging since the molar volume of CaSO_4, produced in this process, is larger than that of the CaO. For prevention of the pore plugging, preparation methods of macroporous CaO by swelling methods were investigated. In this research, two swelling methods using acetic acid and water vapor were used. Also, the effect of pore size distribution of CaO, prepared by these swelling methods, on N_2O decomposition was examined in the presence of SO_2 in a continuous quartz fixed-bed reaction system. From the results, it was found that the macroporous CaO prepared with water vapor swelling method was active for the catalytic decomposition of N_2O and had good tolerance for sulfation.