Desulfurization of Fuel Oil: Conductor-like Screening
Model for Real Solvents Study on Capacity of Ionic Liquids for Thiophene
and Dibenzothiophene
- Publication date
- Publisher
Abstract
To
screen and use ionic liquids (ILs) as environmental-friendly
extractive solvents in removing aromatic sulfur compounds (S-compounds)
from fuel oils, the knowledge of their capacity for S-compounds (or
solubility of S-compounds in ILs) is very important. In this work,
the capacities of 1860 potential ILs (30 anions, 62 cations) for two
representative S-compounds of thiophene (TS) and dibenzothiophene
(DBT) are calculated using conductor-like screening model for real
solvents (COSMO-RS). The influences of cation family, cation alkyl
chain length, cation symmetry, anion nature, anion alkyl chain length,
and functional group on the capacity are extensively discussed and
are understood from microlevel view with σ-profile, σ-moments,
and COSMO-RS energies. It is observed that the capacity is very dependent
on cation and anion structure characteristics and is in a very wide
range (e.g., 10<sup>–3</sup>∼10<sup>1</sup> for TS,
10<sup>–3</sup>∼10<sup>2</sup> for DBT); the van der
Waals (vdW) and hydrogen-bonding (HB) energies have significant effects
on the capacity. Increasing the nonpolarity and vdW energies of cation
or alkyl chain on anion, or the polarity and HB energies of anion,
can favor the capacity. This work is valuable to rationally select
or design the ILs for desulfurization of fuel oils