1070-4272/02/7512-1956 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 12, 2002, pp. 1956!1959. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 12, 2002,
Original Russian Text Copyright + 2002 by Stavitskaya, Goba, Tsyba.
AND ION-EXCHANGE PROCESSES
Comparison of Various Procedures for Regeneration
of Activated Carbons Used for Recuperation of Ethyl Acetate
S. S. Stavitskaya, V. E. Goba, and N. N. Tsyba
Institute of Sorption and Endoecology Problems, Ukrainian National Academy of Sciences, Kiev, Ukraine
Received November 15, 2001; in final form, October 2002
Abstract-The efficiency of various procedures (chemical, thermal, and electrochemical) for regeneration
of activated carbons used for recuperation of ethyl acetate was studied. For each procedure, the optimal con-
ditions were determined for complete regeneration of the sorption capacity of activated carbons without sig-
nificant structural changes. The possibility of eliminating the interfering catalytic effect of carbon in its con-
comitant oxidation in the course of operation, causing loss of the target product, was evaluated.
Activated carbons (ACs) are widely used for deep
purification and drying of various gases and liquids,
for treatment of gas mixtures to isolate individual
components, and in recuperation for recovering valu-
able products from industrial exhaust gases and li-
quids. Sorbents used in continuous processes, along
with high sorption capacity and selectivity with respect
to the target product, should be easily regenerated.
Activated carbons belong to such type of sorbents.
Due to the expanding areas of AC application 
and short supply of carbon sorbents, their regenera-
tion is a topical problem.
Along with high sorption capacity and mechanical
strength, activated carbons used for recuperation of
vapors of organic solvents (benzine, ethanol, ethyl
acetate, etc.) should have low retention power.
One of the main stages in regeneration of organic
solvents by ACs is recovery of the sorbed material,
usually performed by steam treatment ; simulta-
neously, the pores of sorbent are cleared, i.e., the sor-
bent is regenerated. A recuperation installation oper-
ates in such a mode (sorption-steam treatment) during
many cycles, but, in the course of time, the sorption
capacity of ACs decreases, especially due to filling
of the sorbent pores with impurities contained in the
target product and unremovable by steam treatment.
Such a spent material should be substituted with fresh
sorbent or regenerated. Hence, development of pro-
cedures for treatment of the spent ACs, providing
complete regeneration of their sorption capacity, is
very important. Despite considerable amount of pub-
lished data on this problem , development of
simple and efficient procedures for regeneration of
spent carbons is still urgent, because they can provide
significant economy of the resources, prolong the op-
eration life of the deficient sorbents, and decrease the
amount of waste.
In this study, we analyzed the physicochemical
properties and structural characteristics of the initial
and spent Sorbon (Austria) and AR-V (Ukraine) car-
bons used in recuperation of ethyl acetate (common
solvent used, e.g., in production of adhesive tapes)
and the possibility of regeneration of these carbons by
various procedures. The efficiency of various proce-
dures (chemical, thermal, and electrochemical) 
for regeneration of activated carbons used for ethyl
acetate recuperation was compared. After a large num-
ber of operation cycles, the AC sorption capacity de-
creases by a factor of 2.533, and its further opera-
tion in the sorption-steam regeneration mode, with
the regeneration performed directly in an adsorber,
becomes inefficient. The experimental data show
that the main contaminants, which block pores and
decrease the sorption capacity, are varnishes, pig-
ments, and other high-molecular-weight compounds
and some volatile products.
The following desorbing agents were used: water,
0.0533.00 M HCl, 1.0035.00 M H
nia, ethanol, acetone, and various mixtures of these.
The elution regeneration was performed under stat-
ic conditions on bringing a 20-g potion of activated
carbon in contact with a desorbing solution (100 ml)
for 24 h, with intermittent stirring. After the treatment,
the solid was separated from the solution, washed