Liquefaction of olive husk by supercritical fluid extraction

Olive husk was converted to liquid products by using some organic solvents, such as methanol, ethanol and acetone. Supercritical fluid extraction (SCFE) is suitable for the olive husk material. The most effective solvents are acetone for non-catalytic SCFE and methanol for NaOH catalytic SCFE of the olive husk samples. The yields of SCFEs with methanol, ethanol dr acetone were 27.4, 41.5 and 43.2% at 523 K; 40.8, 50.9 and 56.6% at 563 K; and 44.3, 55.1 and 63.0% at 583 K, respectively. The methanol solubles increased from 27.4 to 49.1% (at 523 K), 40.8 to 69.2% (at 563 K) and 44.3 to 84.4% (at 583 K) with 10.0% NaOH catalyst. The catalyst appeared to have a positive effect on the percentage yields in the catalytic methanol runs. Polar components are much more than the non-polar components in the SCFE extracts. On the contrary, non-polar components are much more than the polar components in the catalytic runs. Thus, it has been expressed that some reduction reactions, as well as some cracking reactions, might have occurred during the catalytic SCFEs. (C) 2000 Elsevier Science Ltd. All rights reserved.