Efficient and selective mercaptans removal from aviation kerosene by porous alkaline alumina adsorbents: Synthesis, characteristics and application

The excessively high mercaptan content in straight-run distillation aviation kerosene has led to severe issues such as inferior product quality, equipment corrosion, and environmental pollution, which have become major obstacles restricting the sustainable development of the modern aviation industry. In order to break through the technical limitations of the traditional oxidation-adsorption combined desulfurization process, in this study, a porous alkaline alumina adsorbent was synthesized for efficient selective removal of mercaptans. The specific surface area of the prepared adsorbent reached 338.9 m 2  g −1 and the pore volume reached 0.5 Å. Besides, the mechanical strength was up to 9.417 MPa. Batch static adsorption experiment results showed that as-prepared adsorbents had excellent adsorption performance for mercaptans, thioesters, thioethers, as well as benzothiophene and dibenzothiophene in the single-component simulated oils. The saturated adsorption capacities of 2-methylbutyl mercaptan, dimethyl disulfide and dibutyl sulfate reached 9.85 mg g −1 , 16.04 mg g −1 and 17.02 mg g −1 , respectively. Additionally, the maximum adsorption performances of benzothiophene and dibenzothiophene were up to 14.14 mg g −1 and 10.35 mg g −1 , respectively. Meanwhile, the selective adsorption capacity of mercaptans in aviation kerosene was as high as 10.84 mg g −1 without the chromaticity change. By combining multiple adsorption kinetic models, the mechanisms of multi-stage adsorptive desulfurization and selective mercaptan adsorption were revealed. Furthermore, the performance loss was less than 10 % after 5 consecutive cycles by carrying out an optimized combination scheme of acetone pre-washing with 40 kHz ultrasonic wave followed by 150 °C nitrogen regeneration. This research can provide theoretical and technical support for the development of a high-efficient and low-consumption process for deep desulfurization of aviation kerosene.