Energy & Fuels, Vol.31, No.9, 9814-9823, 2017
Hot Coal Gas Desulfurization Using Regenerable ZnO/MCM41 Prepared via One-Step Hydrothermal Synthesis
ZnO/MCM41 sorbents with bimodal pore structure were prepared via one-step hydrothermal synthesis. The structure of fresh, sulfided, and regenerated sorbents was characterized using XRD, TEM, SEM, nitrogen adsorption isotherms, and XPS techniques. The results indicate that the desulfurizer with 35% ZnO shows the highest sulfur capacity (11.0 g of S/100 g of sorbents). The optimum regeneration conditions were 650 degrees C, 3000 h(-1) and 6% O-2 concentration. Both ZnO and ZnSiO4 were observed in the regenerated sorbents. The increase of regeneration cycles leads to higher content of the Zn2SiO4. However, it results in no significant effect on the performance of sorbents during five sulfidation/regeneration cycles. It may be due to the transformation of Zn2SiO4 into ZnO under conditions of desulfurization. After five successive sulfidation/regeneration cycles, the sorbents still maintain high sulfur capacity (9.8 g of S/100 g of sorbents) and mechanical strength (80 N/cm).