PEF-Extraction 制药工程与设备基础　Pharmaceutical Equipment Fundamentals　教学课件　.pptVIP

Pharmaceutical Equipment Fundamentals Liquid - Liquid Extraction Extraction Extractions use two immiscible phases to separate a solute from one phase into the other. The distribution of a solute between two phases is an equilibrium condition described by partition theory. Liquid-Liquid Extraction Scheme Application of Liquid-Liquid Extraction Extraction processes are well suited to the petroleum industry, to separate heat-sensitive liquid feeds according to chemical type (e.g. aliphatic, aromatic, naphthenic) rather than by molecular weight or vapour pressure. Other major applications exist in the biochemical or pharmaceutical industry, separation of antibiotics and protein recovery. In the inorganic chemical industry, to recover high-boiling components such as phosphoric acid, boric acid, and sodium hydroxide from aqueous solutions. Examples Applications Presence of azeotropes or low relative volatilities are involved (and distillation cannot be used) Dissolved or complexed inorganic substances in organic or aqueous solutions Removal of a component present in small concentrations, e.g. hormones in animal oil Recovery of a high-boiling component present in small quantities in waste stream, e.g. acetic acid from cellulose acetate Recovery of heat-sensitive materials, where low to moderate processing temperatures are needed Solvent recovery is easy and energy savings can be realized Commercial Extractors Dispersed Phase In commercial applications, distinction is normally made between the light phase and the heavy phase, and between the dispersed phase and the continuous phase. The choice of the dispersed phase depends on flow rates, viscosities and wetting characteristics of both phases and is usually based on experience. Dispersed and Continuous Phases Typical Extraction System Ideal Stage Mixer-Settler reliability, operating flexibility, and high capacity a mixer for contacting the two liquid phases to bring about mass transfer, and a settler for their me