Utilizing polycyclic aromatic sulphur heterocycles to develop hypercrosslinked microporous polymeric adsorbents for deep desulphurization of fuels

Abstract

Adsorptive desulphurization is a well-known method for removing polycyclic aromatic sulphur heterocycles (PASHs) from petroleum fractions. Nevertheless, due to the non-destructive adsorption mechanism, managing the adsorbed carcinogenic PASHs remains a major challenge. In the present research, a prototype is presented to manage three PASHs (thiophene, benzothiophene and dibenzothiophene) by using them to develop hypercrosslinked microporous polymeric adsorbents (yield > 90%) within 60 min via microwave assisted synthesis. Textural properties including specific surface area (401–628 m2 g−1), controlled pore size (1.1–1.7 nm) and pore volume (0.24–0.29 cm3 g−1) have been estimated. The developed adsorbents are used for desulphurizing diesel fuels. Batch adsorption studies result in the sulphur adsorption capacities of 6.7 and 6.4 mgS g−1, for 100 ppm and 10 ppm-dosed simulated fuels respectively. Thermodynamic, kinetics and adsorption isotherm studies are performed using the batch adsorption studies. Column adsorption studies exhibit sulphur breakthrough capacities of 7.2 and 0.62 mgS g−1 for 100 ppm and 10 ppm-dosed simulated fuels respectively. The combine effect of textural properties and π electron density on the adsorption capacity is discussed. The present work not only demonstrates a sustainable management cycle of PASHs but also utilized them for deep desulphurization of fuels.