Effect of High-Pressure Impregnation on Structure Variation and Desulfurization Property of a Zn-Based Sorbent Prepared Using Lignite as a Support

Abstract

In this study, a series of zinc (Zn)-based sorbents were prepared by high-pressure impregnation under different conditions of time and pressure, followed by fixed-bed pyrolysis using lignite as a precursor of support and zinc nitrate [Zn(NO3)2] as an active component precursor. The desulfurization performances of lignite and sorbents were measured. Moreover, they were characterized by X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), N2 adsorption, transmission electron microscopy–energy-dispersive X-ray (TEM–EDX), and scanning electron microscopy–energy-dispersive X-ray (SEM–EDX) techniques. The ambient conditions involved in hydrothermal synthesis are favorable for the efficient uploading of Zn(NO3)2 and the improvement of lignite texture during high-pressure impregnation. The content of Zn in prepared sorbent and the utilization rate of the active component can reach over 20 and 90%, respectively. The impregnation pressure and time are the main factors influencing the desulfurization perfo...