Application of aminated chitosan/functionalized carbon nanotube (CNT) nanocomposite in adsorption desulfurization of fuels containing dibenzothiophene (DBT)

The desulfurization process of fuels is a requirement due to environmental pollution. Different techniques are used in the desulfurization process such as adsorption desulfurization. In this work, aminated chitosan and functionalized carbon nanotube were used to prepare adsorbent nanocomposite and as a model sulfur-containing aromatic compound, dibenzothiophene (DBT) was employed. Fourier transform infrared spectroscopy, scanning electron microscopy and tunneling electron microscopy, and the N2 adsorption–desorption isotherm techniques were used for the characterization of the synthesized nanocomposite. The microscopic images revealed the structure of the adsorbent was mesoporous with a pore diameter of about 21 nm. The desulfurization study was conducted by batch adsorption experiments in various mass-loaded adsorbents, contact time, concentration, and temperatures for thermodynamic and kinetic behavior of adsorbents. The results showed adsorption capacity and removal efficiency of DBT were 36.4 mg/g and 64.1%, respectively. The best-fitted kinetic and isotherm models were obtained to be the pseudo-second-order model and Frendulich model, respectively. Also, by comparing the pristine nanocomposite (pristine chitosan) desulfurization results with functionalized ones, it showed a 20% enhancement in adsorption capacity by an increase in amine group numbers. According to the results of this study, this novel nanocomposite has the potential to be used in the adsorption desulfurization process.