Preparation of walnut shell-based activated carbon and its properties for simultaneous removal of H2S, COS and CS2 from yellow phosphorus tail gas at low temperature

Abstract

Walnut shell-based activated carbon (WSBAC) was prepared used to simultaneously remove H2S, COS and CS2 from yellow phosphorus tail gas and closed carbide furnace tail gas. The influences of different preparation conditions (carbonization temperature, activating agent species, activating agent content, activation temperature) on the simultaneous removal efficiency of H2S, COS and CS2 were investigated. The results showed that the WSBAC carbonizated at 600 °C, then activated with 0.5 times KOH at 700 °C had the highest sulfur capacity (52.67 mgS/gWSBAC). The structure and surface properties of the catalysts were characterized by Brunauer–Emmett–Teller (BET) method, and the results showed that the high BET surface area (484.26 m2/g), high micropore volume (0.261 cm3/g) and more pore sizes of 0.3–1.8 nm were conducive to the simultaneous removal of H2S, COS and CS2. X-ray photoelectron spectroscopy results showed that the most of products on the exhausted WSBAC were S/SO4 2− species which accumulated on the WSBAC’s surface and had a negative effect on the adsorption activity.