Ind

Abstract

The objectives of this research is to study the influence of flushing activities on crude waxes yield, and to study the extraction of waxes from pine needles by using supercritical fluid C0 2 technology. The extraction was carried out at an 40 0 C extraction temperature and at various extraction pressures. consisting of 9,14,24 and 30 MPa. Crude waxes were precipitated in the first cold trap at 6-7 MPa intermediate pressure and 0 0 C, and the rest of it was precipitated in the second cold trap at an 0,1 MPa with a similar temperature. After extraction, it was always followed by flushing activities through two steps to get waxes which still remained in the valves and or in the line on the system. First flushing was performed with supercritical fluid extraction without any sample in the extraction cell. The second flushing was conducted with a chloroform solvent. Pure waxes of were purified and analysed by using High Performance Liquid Chromatography (HPLC). Results indicated that the flushing activities with supercritical fluid extraction without any sample in the extraction cell followed by a chloroform solvent had agreat effect on crude waxes yield. At a 30 MPa extraction pressure and at an 40°C extraction temperature, supercritical fluid extraction with flushing gave crude wax yield four time greater than the cude waxes yield obtained by supercritical fluid extraction without any flushing, even to the crude waxes yield from the chlorofrom solvent extraction. The increase in extraction pressure caused an increase in crude waxes, both obtained from the first and the second cold traps. Moreover, HPLC analysis of pure waxes revealed that the elution of pure waxes took 3.70 - 3.90 minutes. lt was also shown that an increase in extraction pressure led to an increase in pure waxes.