Recovery oflonic Liquid [Bmim][FeCI.I] After Sulfur Extraction From Model Oil Using Liquid-Liquid Extraction Process

Ionic Liquid (IL) is proven to be able to extract sulphur compound from
petroleum distillates such as diesel and gasoline providing an alternative to replace
the conventional sulphur removing method that is the Catalytic
Hydrodesulphurization (HDS), which requires both high temperature and pressure.
Many researchers have pointed out the major concerns in the use of IL is their
relatively high cost, which makes their recycling an important issue for further
study. In addition, currently, quite limited studies are being conducted on the
recovery, regeneration or recycling of IL after extractive desulphurization.
Therefore, this research project is conducted where attention are given to the
recycling and recovery of the chosen IL that is, 1-butyl-3-methylirnidazolium
tetrachloroferrate [Bmirn][FeC4] using Liquid-liquid Extraction (LLE) method with
a co-solvent, hexane. The aim of this research is to study the recyclability of the IL
and to investigate on the effect of three manipulated variables which are, the contact
time of the regeneration process, the ratio between sulphur-loaded IL to the cosolvent
and the recovery process temperature on the recovery efficiency in term of
sulphur removal. Project scope are divided into four stages; synthesis of the
[Bmim][FeC4] IL, extraction of benzothiophene from model oil Dodecane,
recovery of the sulphur-loaded [Bmirn][FeC4] using hexane as solvent and lastly to
re-use the recovered [Bmim][FeC14]. The characterization is done using Fourier
Transform InfraRed (FT-IR) and Carbon, Hydrogen, Nitrogen and Sulfur Analyzer
(CHNS). The approach for this project is mainly LLE. Extractive desulfurization
between [Bmirn][FeC14] and model oil containing sulphur is done to obtained
sulphur-loaded [Bmim][FeC14] and extraction using hexane is conducted to recover
the IL. The recovered [Bmim][FeC4] is then reused for extractive desulfurization
and the process is repeated. Recyclability is evaluated without recovery. The result
shows the chemical composition of [Bmim][FeC4] does not change meaning that
the recpvery process is a successful and optimizations on IL to solvent ratio prove
that ratio of I :2 is the best option for regeneration. 80 minutes contact time and
higher temperature ranging between 45"C to 65"C gives the highest efficiency of
recovery.