1070-4272/02/7508-1349 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 8, 2002, pp. 1349!1353. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 8, 2002,
Original Russian Text Copyright + 2002 by Sharipov, Faizrakhmanov.
OF FOSSIL FUEL
Some Properties of Petroleum Sulfoxides Suitable for Extraction
A. Kh. Sharipov and I. S. Faizrakhmanov
Institute of Petrochemistry and Catalysis, Bashkortostan Academy of Science and Ufa Scientific Center,
Russian Academy of Sciences, Ufa, Bashkortostan, Russia
Bashkir Research and Planning Institute of the Building Materials Industry, Ufa, Bashkortostan, Russia
Received February 7, 2001
Abstract-Several fractions of diesel fuel recovered from Arlan crude oil were treated with hydrogen per-
oxide, and the sulfoxides formed by oxidation of petroleum sulfides were isolated with aqueous sulfuric acid.
The water solubility of these sulfoxides and their limiting extraction capacity with respect to neodymium
nitrate were determined. Correlations between several characteristics of the petroleum sulfoxides [water
solubility, limiting extraction capacity with respect to neodymium(III) nitrate, phase separation time under
standard conditions, and viscosity] and the boiling range of corresponding petroleum fractions were analyzed.
As noted in , sulfoxides find growing applica-
tion as extractants in hydrometallurgy. The most im-
portant parameters of extractants used for recovery
of metals from aqueous solutions are their water sol-
ubility R, limiting extraction capacity [in particular,
with respect to neodymium(III) nitrate] E
separation time t
under standard conditions, and
viscosity h .
In this work, we studied the correlation between
the properties of petroleum sulfoxides and the boiling
ranges of the petroleum fractions used for their pre-
The sulfoxides were prepared from a diesel fraction
of the Arlan crude oil. The initial and final boiling
points of this fuel were 211 and 360oC, respectively.
The total sulfur content was 2.2 wt %, including
1.15% sulfide sulfur. The composition of sulfides
contained in the diesel fuel was determined on an
Finnigan-402 gas chromatograph-mass spectrometer
. The sulfide sulfur content S
iodometrically . The sulfides mainly include mono-
cyclic and bicyclic thiaalkanes.
The initial diesel fuel was fractionated on a high-
performance distillation tower at 435 torr and the re-
flux ratio equal to 5. To prepare sulfoxides, these
petroleum fractions were oxidized with 30% hydrogen
peroxide [GOST (State Standard) 177388].
The oxidative conversion of sulfides to sulfoxides
was performed by the technique described in .
The resulting sulfoxides were isolated by extraction
with 62% aqueous sulfuric acid . This aqueous
sulfuric acid containing sulfoxides was neutralized
with aqueous sodium carbonate, washed with aqueous
sodium sulfate, and then kept under reduced pressure
(803100 torr) to remove emulsified and dissolved
water. The following characteristics of dehydrated
sulfoxides RR`SO were determined: the sulfoxide
sulfur content S
, by potentiometric titration ;
molecular weight M
, cryoscopically ; and
water solubility R, by a technique developed by
us. Namely, a sulfoxide sample (10 ml) was added to
distilled water (60 ml) placed in a separatory funnel
and this mixture was shaken for 15 min. The resulting
emulsion was centrifuged (3000 rpm) for 20 min.
The centrifuged aqueous solution (25 ml) was sam-
pled, and petroleum sulfoxides were extracted by suc-
cessive threefold contact with fresh portions of chlo-
roform (20 ml).
All chloroform extracts were collected in a 100-ml
round-bottomed flask. This flask was heated on a wa-
ter bath to remove chloroform and trace amounts of
water. Chloroform was removed at atmospheric pres-
sure, and water, under 1003200 torr. The nonvolatile