(644b) Synthesis and Application of Amino Acid Ionic Liquid-Based Deep Eutectic Solvents for Oil-Carbonate Mineral Separation

Synthesis
and application of amino acid ionic liquid-based deep eutectic solvents for
oil-carbonate mineral separation

Ning
KANG^a, Lin HE^a,b, Hong SUI^a,b,c, Zisheng ZHANG^a,d

^a
School of Chemical Engineering and Technology, Tianjin University, Tianjin
300072, China.

^b
Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),
300072, China.

^c
National Engineering Research Centre of Distillation Technology, Tianjin,
300072, China.

^d
Department of Chemical and Biomedical Engineering, University of Ottawa,
Ottawa, ON K1N 6N5, Canada.

The
Indonesian asphalt rock is one of the carbonate unconventional oil ores, which
has been attracting increasing attention from the industry due to its huge
geological reserves (~1 billion barrels in situ)(Li et al., 2012)
.
To unlock this kind of petroleum ore, different methods have been proposed, and
the solvent extraction (Nikakhtari et al., 2013, He et al., 2015)
has been considered to be a potential method for the ore processing due to the
following advantages: high efficiency, low or no water consumption, mild
operation conditions and good applicability for oil-wetted ores. Recently, much
of the attention has been paid on developing new solvents or innovative process
aids with high extraction
efficiency. The ionic liquids with unique properties have been applied to enhance
the solvent extraction process. It is found that the application of ionic
liquids together with solvents not only increases the oil recovery, but also
improves the product quality with negligible fines being entrained. (Painter et al., 2009, Painter et al., 2010).
However, the high cost and complicated synthesis process of the present involved ILs restrict their
further applications in oil sands extraction.

In
the present study, to allow the process much more cost-saving, cheaper and
environment friendly chemical agents, deep eutectic solvents (which are considered as potential alternatives to
traditional ionic liquids) has been synthesized by protonated Tryptophan salt
and urea (i.e. TrpBF₄/U). When mixing with the ethanol and toluene,
the TrpBF₄/U would form a non-aqueous and surfactant-free
micro-emulsion with the emulsion droplets less than 7 nm. Owing to the low interfacial
tension (0.95mN/m), this newly prepared TrpBF₄/U micro-emulsion was
found to perform well in separating the extra-heavy oil from carbonate asphalt
rocks (up to 93% of bitumen recovery in a single extraction), resulting in
better oil quality with less solid entrained (1.07 mg of solids/mL of solvent) compared
with the previous ionic liquids (i.e., [Emim]BF₄). Results of water
drop penetration time and elemental composition of solid surfaces also showed
TrpBF₄/U plays an important role in interfacial alternation at the
oil and mineral surfaces. It is also found that the TrpBF₄/U
micro-emulsion could be recycled at least 4 times without sacrificing the
extraction efficiency.

These
findings of the TrpBF₄/U micro-emulsion showed promising application
in unconventional oil separation. It is also believed this kind of materials
would be applied in other related extraction, such oil-contaminated soil
remediation, bio-fuels extraction, deinking, etc.

References:

He, L., F. Lin, X. G. Li, H. Sui and Z. H. Xu, 2015. Interfacial
sciences in unconventional petroleum production: from fundamentals to
applications. Chemical Society Reviews 44, 5446-5494.

Li, X., L. He,
G. Wu, W. Sun, H. Li and H. Sui, 2012. Operational Parameters, Evaluation
Methods, And Fundamental Mechanisms: Aspects of Nonaqueous Extraction of
Bitumen from Oil Sands. Energy & Fuels 26, 3553-3563.

Nikakhtari, H.,
L. Vagi, P. Choi, Q. Liu and M. R. Gray, 2013. Solvent screening for
non-aqueous extraction of Alberta oil sands. Canadian Journal of Chemical
Engineering 91, 1153-1160.

Painter, P., P.
Williams and A. Lupinsky, 2010. Recovery of Bitumen from Utah Tar Sands Using
Ionic Liquids. Energy & Fuels 24, 5081-5088.

Painter, P., P.
Williams and E. Mannebach, 2009. Recovery of Bitumen from Oil or Tar Sands
Using Ionic Liquids. Energy & Fuels 24, 1094-1098.