Removal of Benzothiophene and Thiophene Using Butyl-methyl-imidazolium Dibutylphosphate [BMIM] [DBP] from Crude Oil Model

This report contains the study on desulfurization of crude oil model using butyl-methylimidazolium
dibutylphosphate [BMIM][DBP] (ionic liquid). The classical desulfurization
process involves catalytic hydrogenation of sulfur compounds (hydrodesulfiirization, HDS)
into hydrogen sulfide. The hydrogen sulfide which is separated from the desulfurized crude is
oxidized catalytically with air into elemental sulfur. However, some S-compounds such as
dibenzothiophene, methyl dibenzothiophene, and 4,6-dimethyl dibenzothiophene are less
reactive to HDS. The ionic liquids gained increasing interest over the past years due to its
unique properties both as extractant and also as catalyst. Therefore, extractive desulfurization
using the ionic liquids has been identified as the alternative to the conventional method. The
scope of this study includes preparation of [BMIM][DBP] followed by the characterization
and finally the extraction of benzothiophene and thiophene (sulfur compound, S) from the
crude oil model. The study is mainly done in the lab. It is include determining the sulfur
content in the crude in order to create the crude oil model, characterizing the ionic liquids and
testing the extraction ability of the ionic liquids. Based on the result obtained, the extraction
of benzothiophene from the crude oil model using [BM3M][DBP] is ranging from 50% to
92%. The extraction performance of [BMIM][DBPj for thiophene is between 40% to 67%.
This shows that the extraction performance of [BMIM][DBP] is remarkable. The extraction
performance can be improved if the multiple pass extraction is done. Therefore, the
extractions of sulfur compound using the ionic liquids have the bright potential to replace the
conventional technique.