Liquid products from Verbascum stalk by supercritical fluid extraction

Verbascum stalk mill was converted to liquid products by using organic solv ents, such as methanol, ethanol and acetone, with catalysts (10% NaOH or Zn Cl2) and without catalyst in an autoclave at temperatures of 533, 553 and 5 73 K. The liquid products were extracted by liquid-liquid extraction using benzene and diethyl ether. The yields from supercritical methanol, ethanol and acetone extractions were 44.4, 43.3 and 60.5 wt%, respectively, at 573 K. In the catalytic runs with methanol and ethanol, the extracts were 52.4 and 44.8% using 10% NaOH and 55.5 and 60.6% using ZnCl2, respectively, at 5 73 K. The yields from supercritical methanol increased from 38.2 to 52.4% a s the temperature was increased from 533 to 573 K in the catalytic run. (C) 2000 Elsevier Science Ltd. All rights reserved.