Preparation of Sorbents Loaded on Activated Carbon to Remove H2S from Hot Coal Gas by Supercritical Water Impregnation

Abstract

A series of sorbents were prepared by depositing the oxide particles of Cu, Mn, and Zn onto the activated carbon (AC) using the supercritical water impregnation (SCWI) method. The morphology and structure, amounts of loading metals, pore volume, and surface area of sorbents were characterized by X-ray diffraction (XRD), inductively coupled plasma−atomic emission spectrometry (ICP−AES), and nitrogen sorption measurements. The sulfidation tests of sorbents were performed using a fixed-bed reactor under ambient pressure and simulated coal-derived gas. The results show that the metal-active component, preparation temperature, and impregnation time during SCWI are the main influencing factors of the desulfurization activity of the sorbent. These factors behave mainly by changing the micropore volume and surface area of sorbents and the dispersion of metal oxide particles on the support. The optimal SCWI conditions for preparing Mn-based sorbents are 0.46 mol/L precursor solution concentration, 380 °C preparing...