Influence of carbon-based support on desulfurization performance of Zn-based sorbents prepared by high-pressure impregnation under ultrasound-assistance

Zn-based sorbents were prepared by uploading ZnO particles on different carbon materials (activated carbon, lignite semi-coke, bituminous semi-coke and lignite coke) using high-pressure impregnation under ultrasound-assistance. The physical properties, loading amounts of metal components and desulfurization performances were characterized by BET, XRD, SEM and fixed-bed reactor, respectively. The results show that the high-pressure impregnation under ultrasound-assistance method has a great improvement on the physical structures of carbon-based supports, and the BET surface area of sorbent prepared by lignite semi-coke support increases by 11 times. The type of carbon support affects the desulfurization behavior through the loading and the uniform dispersion of active component on support. The higher availability of active component and abundant pore structures result in a good desulfurization performance for Zn/LSC sorbent, having the maximum desulfurization efficiency, sulfur capacity and breakthrough time of 99.99%, 5.17% and 11.0 h, respectively. The lignite semi-coke is much easier than other carbon-based materials to be modified, and could be well used as support materials for hydrothermally synthesizing sorbent by high-pressure impregnation under ultrasound-assistance.