ADSORPTION PURIFICATION OF UNREFINED VEGETABLE OILS WITH BENTONITE CLAY OF ZYRYANSK DEPOSIT

Abstract

Magnesium ions predominate in the exchange complex of bentonite clay from the Zyryanskoye deposit. The amount of exchange cations varies within 76–95 mmol equivalents. The main rock-forming mineral of Zyryansk bentonite is montmorillonite. The adsorption and desorption isotherm of nitrogen by bentonite clay from the Zyryanskoe deposit has the form of a hysteresis loop, which is typical for bentonite clays from other deposits and corresponds to adsorption in mesoporous solids.
 The dynamics of the content of free fatty acids ((FFA (acid number (AN)) and peroxide compounds ((PC (peroxide number (PN)) in samples of unrefined vegetable oils: sunflower oil “Sloboda” and linseed oil “Yeleya” was studied. Six months later the AN and the PN in unrefined linseed oil, and the AN in unrefined sunflower oil increased, but the numbers did not exceed the maximum permissible values. The PN in unrefined sunflower oil increased by 6.4 times and exceeded the maximum permissible values.
 Isotherms of sorption of FFA and PC by native bentonite clay (NG) of the Zyryansk deposit have been obtained. The kinetics of sorption of FFA and PC of sunflower and linseed oil has been studied. The equilibration time is 90–120 min. The optimum operation of sorption of FFA and PC has been determined (static operation with stirring for 2 h at a ratio of m(clay) : V(oil)=1 g : 40 ml.
 The maximum degree of extraction of FFA from sunflower oil by bentonite clay was 31%; from linseed – 9%. The degree of extraction of PC from sunflower oil by bentonite clay was 48%, from linseed oil – 33%.