Deep removal of 4,6-dimethyldibenzothiophene from model transportation diesel fuels over reactive adsorbent

Abstract

This paper presents a new reactive adsorbent used to effectively remove 4,6- dimethyldibenzothiophene (4,6-DMDBT) from model transportation diesel fuels. This reactive adsorbent was composed of formaldehyde, phosphotungstic acid and mesoporous silica gel. The experiment was based on an assumed condensation reaction of 4,6-DMDBT with formaldehyde using phosphotungstic acid as catalyst in pore spaces. The effect of temperature and the amount of formaldehyde and phosphotungstic acid loaded on the substrate were investigated in a batch system. In the breakthrough experiment, three different model diesel fuels containing 1000 mg/kg 4,6-DMDBT were pumped through a fixed-bed reactor packed with reactive adsorbent at constant temperature and atmospheric pressure, respectively. The experimental results showed that sulfur-free model fuel was obtained at 80°C despite the presence of aromatics. The sulfur capacity of regenerated reactive adsorbent was almost totally recovered.