Performance of Mn and Cn mixed oxides as regenerable sorbents for hot coalgas desulfurization

Mixed oxides, prepared by calcination at 950 degreesC for 6 h of powder mix tures of manganese and copper oxides, have been studied as regenerable sorb ents for hot coal gas desulfurization. For the stabilization of copper in t he oxidation states 2+ or 1+ under strong reducing conditions of coal gas, different concentrations of component oxides have been used enhancing the f ormation of different mixed oxides. Copper was not stabilized by manganese oxides, but its presence in the fresh sorbent was completely necessary beca use it increases the sorbent reactivity and keeps the HBS concentration in the outlet gas from a reactor below 50 ppmv. Thermogravimetric experiments and performance tests in a fixed bed reactor have allowed the optimization of the operating conditions for a sorbent MC (1:0.1) showing a good perform ance in multicycle tests without apparent decay.