Solvent extractors packed column

With liquid feed solutions, however, it is possible to work in a manner analogous to traditional solvent extraction. Pressurized columns can be of the packed-bed type or agitated by magnetic stirrers. Because of the efforts of pilot plant tests, much of the scale-up work has to be carried out in laboratory extractors. From solubility measurements, it is possible to determine parameters in thermodynamic models (e.g., equations of state), which can be used for the simulation of large-scale applications. 

In order to test the laboratory data obtained, a small extractor system was used with those solvents having suitable properties, which were obtainable in sufficient quantities for testing, using natural waters or sodium chloride solutions. The extraction system consists of a 2-inch packed column approximately 4 feet high to which water and solvent were fed countercurrently. An analysis of the resulting extract feed and brine was made to determine the material balance for the system. The data obtained from this column using diisopropylamine as solvent are shown in Table I. The feed concentration was 2000 p.p.m. of sodium chloride. The product contained 490 p.p.m., of which part was the amine hydrochloride. In practice, this would be replaced in the solvent recovery system by an equivalent amount of sodium to give the total salt content indicated. Sufficient data have been obtained to indicate that the calculations... 

Timothy C. Frank, Ph.D. Research Scientist and Sr. Technical Leader, The Dow Chemical Company Member, American Institute of Chemical Engineers (Section Editor, Introduction and Overview, Thermodynamic Basis for Liquid-Liquid Extraction, Solvent Screening Methods, Liquid-Liquid Diversion Fundamentals, Process Fundamentals and Basic Calculation Methods, Dual-Solvent Fractional Extraction, Extractor Selection, Packed Columns, Agitated Extraction Columns, Mixer-Settler Equipment, Centrifugal Extractors, Process Control Considerations, Liquid-Liquid Phase Separation Equipment, Emerging Developments)... 

Isolation of Volatiles. An aliquot of blended pulp (1.2 kg) was diluted with distilled water (700 mL) in a 3-L three-neck flask and vacuum distilled (25-30°C/l mm Hg). Distillation continued for 2.5 to 3 h yielding approximately 500 mL of distillate which was collected in two liquid nitrogen cooled traps. A total of 3.6 kg of fruit pulp was distilled in three batches. The distillates were combined and immediately frozen until use. The combined distillate was extracted in 250 mL batches for 20 h with 60 mL trichloro-fluoromethane (Freon 11, b p 23.8°C) using a continuous liquid-liquid extractor. The trichlorofluoromethane was distilled through a 120 x 1.3 cm glass distillation column, packed with Fenske helices, prior to use. Each extract was carefully concentrated to approximately 100 pL by distillation of solvent using a Vigreux column (16 cm), and a maximum pot temperature of 30°C. 

To determine Irganox 1076, CAO-40, and Santonax R antioxidants in polyethylene the additives were extracted from the polymer by grinding them in a freezer mill then extracting with diethyl ether in a Soxhlet extractor for two days. The ether was then evaporated off and the residues dissolved in 25 cm of 1% by volume of isopropanol in hexane. Using the chromatographic system of a 1% isopropanol in hexane solvent and Corasil II adsorbent (surface area 14 2 mV ) and the conditions outlined below the amount of hindered phenolic antioxidant in the ether extract of the polymer was determined. Column 1000 inm x 2.1 mm, i.d. packing 37-50 u Corasil II (activated at 110°C) carrier 1% (v/v) iso-propanol in hexane flow rate - 0.95 ml/min. 

Figure 8.1.35. Schematic of various large-scale liquid-liquid extraction devices, (a) Packed tower for solvent extraction (b) sieve-plate extraction column (c) an early Scheibel column extraction design (d) Karr column, in which the plates have reciprocating motions (e) centrifugal extractor (f) porous hollow fiber membrane solvent extraction device (see Figure 8.1.13(a) for a detailed design).

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