Ultra-deep catalytic adsorptive desulfurization of diesel fuel using
Ti-silica gel adsorbent at low Ti-loading
Abstract
In this work, the effective ultra-deep catalytic adsorptive
desulfurization (CADS) using Ti-silica gel adsorbent at low Ti loading
range (< 1%) was investigated. The superior CADS capacity
(37.3 mg-S/g-A) and high TOF value (432 h-1) for dibenzothiophene (DBT)
were achieved at 0.6% of Ti loading with high dispersion and low Ti
coordination. The catalytic oxidation of DBT conformed to the
pseudo-first-order kinetic model, and the corresponding rate equation
was well described as rDBT=[(N^2)*k/(K*[CHP])]*[DBT],
where the TiOOR is determined as the intermediate to enable the DBT
oxidation to the corresponding sulfone (DBTO2). The effectiveness of
CADS using Ti-SG was verified in various real low-sulfur diesels with
varied sulfur concentrations and O/S ratios in the dynamic fixed-bed
adsorption and multi-cycle regenerations. This work provides insights on
using low-cost bifunctional catalytic adsorbents at low Ti loading for
effective CADS to realize ultra-deep desulfurization of transportation
fuels.