ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 3, pp. 343−353. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © V.V. Danilevich, L.A. Isupova, I.G. Danilova, R.A. Zotov, V.A. Ushakov,
2016, published in Zhurnal Prikladnoi Khimii, 2016, Vol. 89,
No. 3, pp. 289−299.
INORGANIC SYNTHESIS AND INDUSTRIAL
Characteristics Optimization of Activated Alumina Desiccants
Based on Product of a Centrifugal Thermal Activation
V. V. Danilevich
, L. A. Isupova
, I. G. Danilova
, R. A. Zotov
, and V. A. Ushakov
Tomsk State University, pr. Lenina 36, Tomsk, 634050 Russia
Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences,
ul. Akademika Lavrent’eva 5, Novosibirsk, 630090 Russia
Received February 1, 2016
Abstract—Activated alumina desiccants modiﬁ ed with NaOH and KOH were synthesized from the product of a
centrifugal thermal activation of gibbsite, with the subsequent hydration in an acid or alkaline medium, and their
properties were studied. It was shown that the modiﬁ cation makes it possible to raise the dynamic capacity of
desiccants produced from pseudoboehmite by up to a factor of 2 via formation of new super-strong basic centers
the concentration of which grows with increasing content of an alkaline oxide. A correlation was found between
the total concentration of basic centers on the surface of the desiccants and their dynamic capacity in drying of
both dry and humid air. Use of the modiﬁ ed desiccants with high static and dynamic capacity will make it pos-
sible to improve the drying efﬁ ciency.
Desiccants based on active activated alumina are still
in the highest demanded in the market of adsorbents
serving as desiccants. Desiccants are used in deep dehy-
dration of ﬂ owing media (gases and liquids) in modern
oil-reﬁ ning, natural-gas, and chemical industries [1, 2].
The wide application of activated alumina desiccants
(AADs) is due to a number of factors: high efﬁ ciency in
drying of gases with relative humidities of up to 100%,
substantial mechanical strength, readily available raw
materials, and possible multiple regeneration with mini-
mum energy expenditure [3, 4].
Despite the comprehensive studies of AADs, the
problem of improving their various characteristics and,
in particular, that of raising the sorption capacity are still
topical. The main approaches used to control the sorption
properties of AADs consists in optimization of the texture
characteristics (speciﬁ c surface area and porous structure)
and phase composition and in chemical modiﬁ cation of
the surface properties of activated alumina, which affects
the number and strength of adsorption centers.
For example, a high-efﬁ ciency activated alumina
drying agent has been developed on the basis of η-Al
at the Institute of Catalysis, Siberian Branch, Russian
Academy of Sciences. The drying agent is produced by
the ecologically safe technique of centrifugal thermal
activation of gibbsite (CTA G), followed by hydration
of the CTA G product to bayerite under mild conditions
[5, 6]. The static capacity of desiccants of this kind at
a relative humidity of 60% reached a value of 24.2 g
O/100 g of drying agent, and the dynamic capacity
(dew point –40°C) was as high as 8.2 g H
O/100 g of
drying agent or 5.07 g of H
O per 100 cm3 of AAD.
This value substantially exceeds similar parameters for
-based AADs produced both by the precipitation
and thermal oxidation methods .
The modiﬁ cation of the surface of desiccants with
sulfate ions (via introduction of sulfuric acid solutions
of various concentrations in the stage in which a plastic
paste is prepared from pseudoboehmite- or bayerite-
containing hydroxides produced by the CTA method)
makes it possible to raise the dynamic capacity of γ-Al
desiccants to the level of the η-Al
-based drying agent
by both diminishing the average pore diameter and
making higher the surface acidity .