Desulfurization Kinetics and Regeneration of Silica Gel-Supported TiO₂ Extrudates for Reactive Adsorptive Desulfurization of Real Diesel

Abstract

Desulfurization kinetics and regeneration of silica gel-supported TiO2 extrudates were explored for the reactive adsorptive desulfurization (RADS) process in this work. RADS using TiO2/SiO2 extrudates with varied particle sizes was evaluated. The textural and chemical properties of molded adsorbents were well maintained after extrusion, with a negligible decrease (<0.97%) in the desulfurization capacity for 50 ppm low-sulfur diesel. The RADS of trilobed TiO2/SiO2 was well described with a first-order adsorption kinetic model of ln­(C) = −9.42 × 10–3 t + 3.84, and TiO2/SiO2 extrudates with smaller particle size may provide larger external surface area and shorter diffusion path. The impacts of packing density and weight hour space velocity (WHSV) on fixed-bed dynamic RADS were discussed. The desorption of adsorbed diesel can be well presented by a first-order model, where the total diesel yield of the RADS process reached above 99.5% at a nitrogen purging temperature ≥150 °C. The effects of solvent structure, polarity, and alkalinity on adsorbent regeneration were further illustrated. This work provides an insight into the aspects of kinetics and regeneration of molded adsorbents to pave the way for industrial fixed-bed desulfurization processes.

Synthesis and characterization of AFe2O4 (A: Ni, Co, Mg)–silica nanocomposites and their application for the removal of dibenzothiophene (DBT) by an adsorption process: kinetics, isotherms and experimental design

“…[6][7][8] Furthermore, harsh reaction conditions such as high pressure and temperature are required to obtain low sulfur concentrations in HDS, implying that HDS needs high operating costs for complying with low sulfur hydrocarbon fuels. 1,3,[9][10][11][12][13][14] It should be noted that (ADS) is a favorable method for reaching ultralow sulfur levels since it has various advantages such as low operation temperature and pressure and high selectivity. 15,16 Nevertheless, the essential challenge of this method is the selection of the sorbent with high sulfur removal capacities and thio-selectivity over organosulfur compounds.…”

Science and Technology Progress on the Desulfurization Process of Crude Oil

“…Compared to the hydrodesulfurization process, the reactive adsorbent process was operated at high temperature and ambient pressure with lower hydrogen pressure and thus it is much cheaper from the economic point of view 83,84 . During the reactive adsorption process using Ni/ZnO material, the organosulfur compounds were adsorbed and transformed to Ni 3 S 2 on the surface of ZnO.…”

Ultra‐deep catalytic adsorptive desulfurization of diesel fuel using Ti‐silica gel adsorbent at low Ti‐loading

“…Few studies have focused on Ti‐based adsorbents with low Ti loading, which can be of great significance to improve the adsorption efficiency and adsorbent economics. Moreover, in‐depth understanding of the relationship between structure and catalytic adsorption of adsorbents has not been fully developed yet in the literatures 34,35 …”