ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 5, pp. 716 !721. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + V.N. Bekhterev, E.A. Kabina, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80, No. 5, pp. 737!742.
OF SYSTEMS AND PROCESSES
Technology of Vapor-Phase Extraction of Water-Soluble
V. N. Bekhterev and E. A. Kabina
Research Center for Health Resort Treatment and Rehabilitation, Black Sea Regional Administration
of Specialized Sanatoria, Ministry of Public Health and Social Development of the Russian Federation,
Sochi, Krasnodar krai, Russia
Received June 20, 2006; in final form, March 2007
Abstract-A method of vapor-phase extraction has been suggested for recovery of organic substances from
an aqueous medium. The appropriate apparatus have been developed. The method enables use of both hydro-
phobic and hydrophilic organic liquids. The results of vapor-phase extraction of low-molecular-weight organic
acids are discussed in terms of the kinetic model of the process mechanism.
Numerous technologies are based on extraction of
target products. A considerable experience has been
accumulated in liquid extraction of organic com-
pounds, and theoretical foundations of the process
have been developed, which enables prediction of the
efficiency of extraction systems. At the same time,
the distribution ratios (K
) of well soluble
organic compounds do not exceed 50 even in the best
solvent3water systems . The use of hydrophobic
alcohols (pentyl, decyl alcohols), acetic acid esters
(butyl acetate, heptyl acetate) has shown that the ex-
tractive activity of solvents-homologs steadily grows
as the number of carbon atoms in their molecules
decreases. However, this leads to an increase in the
solubility of an extractive agent in water, which does
not allow (and even rules out) the use of low-molecu-
lar-weight homologs without a special [salting-out]
procedure: introduction of large amounts of neutral
salts into a water sample. A risk of side chemical
processes arises, numerous technological difficulties
are encountered, etc.
Here we suggest a possible solution to the problem
of use of hydrophilic organic liquids for recovery of
water-soluble organic substances: vapor-phase extrac-
tion (VPE). Aqueous solutions of low-molecular-
weight carboxylic acids served as objects of study.
To implement the method of vapor-phase extrac-
tion of dissolved organic substances from aqueous
objects, we developed the device described in .
It served as a basis for creating the extraction unit
schematically shown in the figure . The extraction
unit comprises, in addition to the necessary, but not
shown in the figure, instrumentation for measuring
Device for vapor-phase extraction of organic substances
(VPE unit): (1) liquid batching pump for delivery of the
extractive agent, (2) pipeline for supply of the extractive
agent, (3) distillation vessel, (4) pipeline for feed, (5) steam
line, (6) condenser for condensing the vapor of the extrac-
tive agent with target components, (7) vessel for collection
of the extract, (8) pipe for connecting a compressor or
a vacuum pump, (9) heater, and (10) discharge pipe.