Different Preparation Process versus Performance of MnxOy/MCM-48 Sorbents for Hot Coal Gas Desulfurization

In order to improve the desulfurization efficiency of 50% MnxOy/MCM-48 sorbent, the preparation parameters including synthesis method (excessive impregnation, precipitation, and sol–gel), precursor selection (Mn(Ac)2 and Mn(NO3)2), heating rate during calcination (2°/min, 4°/min, 6°/min, and 8°/min), and calcination temperature (450 °C, 550 °C, 650 °C, and 750 °C) of sorbents were investigated systematically. The structure and composition of different sorbents were characterized by XRD, BET, TG/DSC, H2-TPR, UV–vis, TPSR, and FT-IR techniques. The results indicated that synthesis methods and precursors influenced remarkably the dispersion of active particles while the stable structure of MCM-48 and the dispersion of active particles correlated closely with the heating rate during calcination and calcination temperature of sorbents, which will influence the desulfurization efficiency of sorbents. Therefore, the better dispersion of active particles and integrity of MCM-48 structure will result in better desulfurization performance of sorbents. Thus, the best condition was the calcination temperature of 550 °C with a heating rate of 2°/min using Mn(Ac)2 as precursor by a sol–gel method.