Adsorption performance of calcined coal gangue for ethyl mercaptan

The modified coal gangue with different structures were used as the adsorbents which were prepared via the calcination process with the different temperature, time and atmosphere. The calcined coal gangues were characterized by XRD, FT-IR, TGA, SEM-Mapping, EDS, nitrogen adsorption-desorption isotherms and XPS. The adsorption performance of calcined coal gangue was evaluated via the adsorption of ethyl mercaptan in methane gas. The results show that the internal structures of coal gangue are affected by the calcination temperature and calcination time. The main components in the coal gangue are changed from kaolin to amorphous metakaolin, and the adsorption activity of coal gangue is greatly improved. The carbon content, especially the content of functional groups C-O and C=O in the coal gangue is changed in the difference of calcination atmosphere. When the calcination temperature, time and air content are set at 600°C, 3 h and 0.1 respectively, the breakthrough adsorption capacity of calcined coal gangue for ethyl mercaptan is 39.32 mg·g−1. The coal gangue modified by a simple calcination method has strong adsorption desulfurization performance and this is a typical example of treating waste by waste.