Methyl mercaptan removal from gas streams using metal-modified activated carbon

In this paper, removal characteristics of methyl mercaptan (CH3SH) on virgin activated carbon and the metal-modified activated carbons (M–AC) prepared by sol–gel method were studied by using a dynamic method in a fixed bed. The detailed characterization of the catalyst has been done using Scanning electron microscope (SEM), Energy–dispersive X–ray spectrometry (EDS), X–ray photoelectron spectroscopy (XPS), and N2 adsorption/desorption techniques. The results showed that impregnation of metal oxides on the AC significantly enhanced the removal capacity of methyl mercaptan, despite a notable decrease in microporosity. The catalytic activity of different kinds of metal-containing catalysts decrease in the following sequence: Cu–AC ≈ Ni–AC > Al–AC > Fe–AC > Zn–AC. Moreover, calcinations temperature can influence the catalytic activity of the catalyst greatly. XPS results showed that the methyl mercaptan were oxidized by the catalyst. Sulfate species and methyl thiolate accumulated on the catalyst surface, which can block the pores and reduce the active sites.