SEPARATION SCIENCE AND TECHNOLOGY, cilt.39, sa.11, ss.2677-2694, 2004 (SCI-Expanded, Scopus)
Desorption of salicylic acid from organically modified bentonite by using supercritical fluids (SCFs) was studied. The parameters, such as pressure, temperature, SCF flow rate, and cosolvent (entrainer) concentration, were investigated. A desorption yield of 40 wt% salicylic acid was obtained by using supercritical CO2 by operating at low pressure (300 bar), low temperature (40degreesC), and 2 mL CO2/min, it reached up to 77 wt% in the presence of ethanol as cosolvent 10 vol%. Similarly, a maximum desorption yield of 76 wt% salicylic acid was obtained by using supercritical CO2 by operating at high pressure (500 bar), high temperature (80degreesC), 2 mL SC CO2/min, it reached up to 98 wt% in the presence of ethanol as cosolvent 10 vol%. Hence, it was concluded that the mean contents in the desorbed solute are approximately 1.5-2-fold higher by addition of 10 vol% ethanol than only supercritical CO2 desorption process.