Abstract

COELHO, G.L.V.  and  PAWLISZYN, J.. Desorption of ethyl acetate from modified clays by supercritical carbon dioxide. Lat. Am. appl. res. [online]. 2004, vol.34, n.4, pp.285-288. ISSN 0327-0793.

The supercritical regeneration with carbon dioxide of modified and unmodified clays was experimentally studied after their use to adsorb ethyl acetate from aqueous solutions. Two quaternary amine modifiers (tetramethyl ammonium chlorine / TMA⁺ and hexadecyltrimethylammonium bromide/ HDTMA⁺) were used. The desorption of ethyl acetate adsorbed over the clays was performed with carbon dioxide at temperatures ranging from 301 K to 333 K and pressures ranging from 69.0 bar to 413.8 bar. The regeneration capacity was almost coincidental and high pressure was more favourable to regeneration. The effect of pressure and temperature was characterised under different conditions (gas, liquid and supercritical) and the supercritical has shown to be the best. A crossover effect was observed. The experimental data was fitted to a simple model, being the best results corresponding to desorption with carbon dioxide in its supercritical region.

Keywords : Organo-Clay; Smectite; Adsorption; Extraction; Supercritical; Carbon Dioxide.

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