USING MICROEMULSION-MODIFIED DIATOMITE FOR REMOVING SULFUR FROM COMMERCIAL DIESEL

Abstract

Diatomite or diatomaceous earth is a sedimentary rock composed mainly of diatom siliceous skeletons with high porosity that is often used in adsorption processes. This work investigates the enhancement of diatomite properties using microemulsion systems in the removal of sulfur from commercial diesel. Nonionic surfactants containing microemulsions were used to modify its surface. The adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetry (TG), and N2 adsorption-desorption. A 23 full factorial design was performed to assess the influence of salt concentration on adsorption capacities in the microemulsion aqueous phase (from 20 to 1500 mg/kg). The experiments were carried out at batch temperature (25 to 60 °C) and using a commercial diesel fuel with sulfur concentration from 300 to 1100 mg/kg. Sulfur adsorption capacity increased from 0.436 mg/g to 1.23 mg/g with the optimization of the microemulsion system and with the salt addition. The microemulsion-modified diatomite was able to remove up to 26.53% sulfur from commercial diesel.