Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 5, pp. 836−839.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
V.I. Romanovskii, V.N. Martsul’, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 5, pp. 782−785.
OF SYSTEMS AND PROCESSES
Distribution of Heteroatoms of Synthetic Ion Exchangers
in Pyrolysis Products
V. I. Romanovskii and V. N. Martsul’
Belarussian State University of Technology, Minsk, Belarus
Received April 15, 2008
Abstract—Distribution of sulfur and nitrogen atoms in products of pyrolysis of spent synthetic ion exchangers
AV-17 and KU-2 in the temperature range 50–550°C was studied. The compounds containing heteroatoms were
identified, and their amounts were determined.
Involvement of production and consumption wastes in
economy as secondary raw materials provides resource
saving and environmental protection. Wastes containing
synthetic polymers are considered as raw materials for
production of a wide assortment of materials and articles
for various purposes. However, considerable amounts of
polymer-containing wastes are disposed of on disposal
sites of industrial and municipal wastes, thus considerably
reducing the capacity of these sites.
The majority of studies and practically implemented
technologies for polymer waste reprocessing deal with
thermoplastic materials. However, wastes containing
network polymers cannot be reprocessed into materials
and articles by methods developed for thermoplastics.
Spent synthetic ion-exchange resins are among materials
for which reprocessing technologies have not yet been
developed. Up to now, spent synthetic ion exchangers
were not considered as secondary raw material.
Ion-exchange materials are used in water treatment
processes, in hydrometallurgy, in electroplating, in
food, hydrolysis, and chemical industries, as catalysts
of various chemical processes, in analytical chemistry,
in medicine, in biology, and in pharmaceutical industry
. The operation life of ion exchangers is limited by
a decrease in the exchange capacity and by the loss of
the shape (wear, cracking, etc.).
Spent ion exchangers find no use today and are
disposed of on special sites. In contrast to polymeric
materials, spent ion exchangers contain no fillers,
pigments, stabilizers, and reinforcing components.
Therefore, they can be considered as a promising material
for pyrolytic reprocessing. The products obtained can be
used as chemical raw materials; fractions containing no
sulfur and nitrogen heteroatoms, as fuel or fuel additives;
and the solid residue, if it exhibits sorption properties, as
The functional groups of the most widely used
synthetic ion exchangers contain nitrogen and sulfur. The
distribution of heteroatoms among the solid, liquid, and
gas fractions formed by pyrolysis of spent ion exchangers
strongly affects the choice of their further applications
and the environmental parameters of the process.
Our experiments were performed with spent strongly
basic anion exchanger AV-17×8 and strongly acidic cation
exchanger KU-2×8, used in water treatment for softening
and desalination of river water.
In this study we examined how the conditions of
thermal degradation of spent synthetic ion exchangers
affect the distribution of heteroatoms of functional
In our studies we used differential thermal analysis
(DTA; TA Instrument device, USA; nitrogen atmosphere;
heating rate 10 deg min
; determination accuracy:
temperature ±0.01°C, enthalpy ±0.01 J g
differential scanning calorimetry (DSC 2010 device, Du