Asian Research Journals
http://www.tarj.in
158
Special
Issue
According to Internet information [RUE “National Center for Marketing and Price Study”] - the
main manufacturers of the world market of VA monomer are Celanese (USA), LyondelBasell
(USA), DowChemical (USA), DuPont (USA), INEOS (Great Britain).
Today, zinc acetate deposited on crushed natural active carbons of the ARD, ARD-U brands in
Russia and S-76 abroad is used as a catalyst for the production of vinyl acetate from acetylene in
reactors with a flowing bed. All of them retain the properties and disadvantages inherent in
conventional activated carbons: they have high ash content, differ in an unbalanced ratio of the
volumes of micro- and mesopores, which determines both a relatively low level of catalyst
activity and its rapid deactivation. In addition, when using a reactor with a gushing layer, the low
strength of the carrier and the irregular shape of the particles lead to rapid abrasion of the catalyst
and its entrainment from the reactor. A significant increase in the productivity of the synthesis
process of vinyl acetate can be achieved by switching to zinc acetate catalysts obtained using
nanoporous carbon microspheres as carriers, which are characterized by high strength, low
abrasion resistance, and an optimal porous structure [6-10].
The main methods for producing VA in the gas phase are passing a mixture of acetylene with
acetic acid vapor through a heated catalyst. Catalysts are salts of zinc and cadmium. Silica gel or
activated carbon is used as a catalyst carrier. The reaction temperature lies in the range 210-
250°C. The gas mixture is recommended to be heated to this or slightly higher temperature.
Acetylene is used in excess against theoretical. Particularly emphasized is the need for a quick
passage of the reaction gas mixture over the catalyst, so that only part of the reaction mixture
reacts, and that the VA formed is always surrounded by excess unreacted mixture. Moreover, in
a contacted medium, a VA concentration of about 20% is obtained. The most favorable reaction
temperature is 210-250°C.
Based on the foregoing, the production of vinyl acetate is one of the main tasks of creating new,
economical, non-waste methods in technology, as well as developing effective catalysts with
high selectivity, activity and productivity of modeling technological and process parameters [11-
14].
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