Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 5, pp. 839−840.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © N.D. Ashurova, A.A. Agaev, M.M. Muradov, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 5, pp. 840−841.
Synthesis of Chlorohydrins by a Combined Chemical
and Electrochemical Process of Oleﬁ n Hypochlorination
N. D. Ashurova, A. A. Agaev, and M. M. Muradov
Sumgait State University, Sumgait, Azerbaidzhan.
Received March 18, 2011
Abstract—The possibility of signiﬁ cantly increasing the yield of products and reducing the amount of hazardous
waste was explored for the industrial technology of hypochlorination of unsaturated hydrocarbons.
Production of epoxy compounds, e.g., of propylene
oxide (PO) and epichlorohydrin (ECH), which large-
tonnage products are used mainly for preparation of epoxy
resins, generates large quantities of low-concentration
hydrochloric acid and organochlorine waste [1–3], with
hydrogen chloride formed stoichiometrically with nearly
half of the chlorine spent being consumed. Moreover,
even if the requirements of the appropriate process
regulations are satisﬁ ed, the amount of organochlorine
waste formed in production of ECH reaches 0.5 ton per
ton of the product , which constitutes an important
environmental and economic challenge.
However, with side reactions also taken into account,
the yield of chlorohydrins per atomic chlorine does not
exceed 40–45%. A very important task consists in devel-
opment of a low-waste technology of the process. In this
connection, hydrochloric acid, whose concentration in
the chlorohydrin solution reaches 2–3%, could be used
much more efﬁ ciently, speciﬁ cally, in further synthesis of
chlorohydrins, whereby the chlorine utilization efﬁ ciency
could be increased for these processes.
For the purpose of combining electrochemical hy-
pochlorination of oleﬁ ns in a hydrochloric acid solution
[5–9] with the chemical procedure, we explored the
possibility of using low-concentration hydrochloric acid,
also containing chlorohydrins, as electrolyte. To this end,
an aqueous solution of propylenechlorohydrin (PCH)
and HCl, or of glycerol dichlorohydrin (GDC) and HCl,
which are close in composition to industrial solutions, was
subjected to electrolysis with simultaneous introduction
of propylene or allyl chloride into the reactor.
The reaction was carried out in a 0.8-m-high vertical
reactor with the working volume of 0.37 l, equipped with
a thermostating jacket and a Schott ﬁ lter for supply of
oleﬁ ns. A ruthenium-titanium oxide anode (ORTA) with
the surface area of 10 cm
served as anode, and graphite
rods, as cathode; sodium chloride (2%) was added to the
electrolyte. Upon completion of the reaction the content
of hydrogen chloride and chlorohydrin in solution was
determined by argentometric titration. The results are
presented in the table.
The tabulated data suggest that, upon passing of
the calculated quantity of electricity and olefin, the
hydrochloric acid concentration in solution decreased
to 0.30–0.35%, while the chlorohydrin concentration
increased. This enabled preparation of more concentrated
PCH and GDC solutions in which the concentration of
hydrochloric acid was signiﬁ cantly decreased.
Under the conditions indicated, the chlorohydrins
were obtained in 60–70% current yields. In the absence
of background electrolyte, the current yield decreases