Effect of salt modification and acid activation on ethylene adsorption properties of sepiolite

The adsorption of ethylene (C₂H₄) on sepiolite from Eski?ehir, Turkey and on its salt modified forms (NaS, KS, CaS and MgS) and treated with 1, 3 and 5 M HCl solutions (SH, S3H and S5H) was investigated. The sepiolite samples were characterized using X-ray diffraction, X-ray fluorescence, thermogravimety, differential thermal analysis and N₂ adsorption methods. The C₂H₄ adsorption isotherms of all clay samples were obtained at 20 °C up to 37 kPa. The uptake of C₂H₄ decreased as HS > CaS > NaS > S > MgS > KS > H3S > H5S for sepiolite samples. Capacity of sepiolites for C₂H₄ ranged from 0.478 to 0.622 mmol/g. It was found that the adsorbed amount of C₂H₄ on sepiolite samples decreased with increasing acid concentrations.