Regeneration of AgXO@SBA-15 for reactive adsorptive desulfurization of fuel

Abstract

Adsorbent regeneration is critical for a continuous adsorption-regeneration process and often underestimated. In this work, the regeneration of bifunctional Ag X O@SBA-15 for [O]-induced reactive adsorptive desulfurization of liquid fuel is reported and further investigated. The spent Ag X O@SBA-15 was regenerated in various types of solvents followed by calcination and tested in multiple desulfurization-regeneration cycles. The effects of regenerate solvents were also compared systematically. The original and regenerated Ag X O@SBA-15 was characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, N 2 adsorption, X-ray photoelectron spectroscopy and atomic absorption spectrometry. The recovery of desulfurization capacity using various solvents follows the order of acetonitrile [ acetone [ ethanol [ methanol [ water. Owing to the complete reduction of silver species to Ag 0 and severe agglomeration of Ag 0 , the bifunctional Ag X O@SBA-15 demonstrating [ 85% (2.60 mg-S/g) of sulfur removal dramatically reduced to \ 46% (1.56 mg-S/g) after only 1st-cycle regeneration. It is suggested that polar organic species strongly adsorbed (or residual) on the spent Ag X O@SBA-15, in that case, after solvent wash may contribute to the accelerated decomposition of Ag ? to Ag 0 in the following calcination step. The desulfurization capacity decreased rather mildly in the later regeneration runs. Cautious choice of regeneration conditions and strategies to rational design stabilized adsorbents is required to avert the adsorbent deactivation.

Review of Adsorptive Desulfurization of Liquid Fuels and Regeneration Attempts

“…The adsorption tests in the aforesaid studies were performed at room temperature (30–35 °C). The adsorbents (with metal) showed the maximum sulfur adsorption capacity in the range of 2.60–32.6 mg/g over the initial concentration range of 150–1000 ppm. ,− …”

Batch Oxidative Desulfurization of Model Light Gasoil over a Bimetallic Nanocatalyst

“…On the other hand, it is reported that incorporation of silver oxide into an ODS catalyst matrix may combine the selective adsorption capacity of silver ions for sulfur compounds with the catalytic activity of ZnO/ HY-zeolite, which is helpful to enhance the selective ODS of diesel fuel [43]. This efficient selectivity for DBT molecules may be attributed to good π complexation between DBT and silver ions.…”

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

“…As for the regeneration of adsorbents, the conventional method for the desulfurization process is high-temperature (623–823 K) air treatment. Considering the problem of high energy consumption and cost of operation during high-temperature air treatment, some researchers reported that solvent (i.e., methanol, toluene, and acetonitrile) washing can realize the regeneration of adsorbents at mild conditions. − Nevertheless, the effects of different types of solvents on the regenerability of materials have not been fully clarified.…”