Removal of SO over modified activated coke desulfurizers at low temperatures.

A novel modified activated coke (AC) desulfurizer prepared by impregnation of metal oxides (Fe, Cu, Ni, Mn, Co), rare earth elements (Ce, La), and potassium hydroxide (KOH) was investigated. Experimental results showed that the desulfurization (DeSO) efficiency of the AC impregnation of Fe (Fe/AC) was higher than other samples with impregnation of metal oxides at 120 °C and a space velocity of 8,000 h. At the same operating conditions, the Ce/AC was more effective in two samples with impregnation of rare earth elements. As the Fe content was increased from 3 to 5 % (mass %), DeSO efficiency increased significantly, and kept stable at higher Fe contents (10 %). The effect of desulfurization temperature was also investigated, which revealed that, with increasing temperature from 80 to 120 °C, the DeSO efficiency gradually increases, while the DeSO efficiency decreased with increasing temperature from 120 to 140 °C. [ABSTRACT FROM AUTHOR]