Removal of H2S from simulated blast furnace gas by adsorption over metal-modified 13X zeolite

Abstract

With the promulgation of new regulations, it’s of great significance to desulfurization from blast furnace gas (BFG) to meet the clean production of iron making industry. Among different desulfurization technologies, zeolite-based sorbents are extensively studied due to the easy operation, low operating cost, and long service life. In this research, the 13X zeolite was selected, and it was ion-exchanged by different metal elements (Cu, Zn, Co, Mn) to prepared a series of sorbents. A fixed bed was used to evaluate their desulfurization behavior, and the XRD, SEM, ICP-OES, XPS, N2 adsorption, and CO2-TPD were carried out to characterize the physical and chemical properties of sorbents. The effects of water vapor content and desulfurization temperature on the removal of H2S were investigated. The regeneration performance of sorbent was also explored. The results showed that the Cu25X-Ex sorbent has the highest breakthrough sulfur capacity of 7.71 g S/100 g sorbent in dry simulated BFG. The breakthrough sulfur capacity of Cu25X-Ex was 4.52 g S/100 g sorbent when the water vapor content is 5 %. The CO2-TPD results showed that the basic sites were favorable for the adsorption of H2S on the surface of zeolite. The XPS results illustrate that the forms of S adsorbed on Cu25X-Ex sorbent were CuS, CuS2O3, and CuSO4, so it is suggested that the reaction between adsorbed H2S with the metal cations in sorbent occurred subsequently. The research indicated that Cu25X-Ex sorbent has potential applicability in the desulfurization of blast furnace gas.