Organic chemicals industry, solvent extraction

Solvent Extraction Performance in Organic Chemicals Industry (Ethylene Oxychlorination Subcategory) Using Extractor (Multi-stage Extractor and Stripper) and Solvent (paraffin)... 

Other Organic Processes. Solvent extraction has found appHcation in the coal-tar industry for many years, as for example in the recovery of phenols from coal-tar distillates by washing with caustic soda solution. Solvent extraction of fatty and resimic acid from tall oil has been reported (250). Dissociation extraction is used to separate y -cresol fromT -cresol (251) and 2,4-x5lenol from 2,5-x5lenol (252). Solvent extraction can play a role in the direct manufacture of chemicals from coal (253) (see Eeedstocks, coal chemicals). 

Solvent Extraction Reagents. Solvent extraction is a solution purification process that is used extensively in the metallurgical and chemical industries. Both inorganic (34,35) and organic (36) solutes are recovered. The large commercial uses of phosphine derivatives in this area involve the separation of cobalt [7440-48-4] from nickel [7440-02-0] and the recovery of acetic acid [61-19-7] and uranium [7440-61-1]. 

Solvent extraction is used in nnmerons chemical industries to produce pure chemical compounds ranging from pharmaceuticals and biomedicals to heavy organics and metals, in analytical chemistry and in environmental waste purification. The scientific explanation of the distribution ratios observed is based on the fundamental physical chemistry of solute-solvent interaction, activity factors of the solutes in the pure phases, aqueous complexation, and complex-adduct interactions. Most university training provides only elementary knowledge about these fields, which is unsatisfactory from a fundamental chemical standpoint, as well as for industrial development and for protection of environmental systems. Solvent extraction uses are important in organic, inorganic, and physical chemistry, and in chemical engineering, theoretical as well as practical in this book we try to cover most of these important fields. 

The principle of solvent extraction—the distribution of chemical species between two immiscible liquid phases—has been applied to many areas of chemistry. A typical one is liquid partition chromatography, where the principle of solvent extraction provides the most efficient separation process available to organic chemistry today its huge application has become a field (and an industry ) of its own. The design of ion selective electrodes is another application of the solvent extraction principle it also has become an independent field. Both these applications are only briefly touched upon in the chapter of this book on analytical applications (Chapter 14), as we consider them outside the scope of... 

Common to all or most solvent extraction operations in the mining industry is the problem of stable formation of cruds. The crud can constitute a major solvent loss to a circuit and thereby adversely alfect the operating costs. Because there can be many causes of crud formation, each plant may have a crud problem unique to that operation. Factors such as ore type, solution composition, solvent composition, presence of other organic constituents, design and type of agitation all can adversely alfect the chemical and physical operation of the solvent extraction circuit and result in crud formation [32-34]. 

The separation of organic mixtures into groups of components of similar chemical type was one of the earliest applications of solvent extraction. In this chapter the term solvent is used to define the extractant phase that may contain either an extractant in a diluent or an organic compound that can itself act as an extractant. Using this technique, a solvent that preferentially dissolves aromatic compounds can be used to remove aromatics from kerosene to produce a better quality fuel. In the same way, solvent extraction can be used to produce high-purity aromatic extracts from catalytic reformates, aromatics that are essentially raw materials in the production of products such as polystyrene, nylon, and Terylene. These features have made solvent extraction a standard technique in the oil-refining and petrochemical industries. The extraction of organic compounds, however, is not confined to these industries. Other examples in this chapter include the production of pharmaceuticals and environmental processes. 

Acetic acid is an important intermediate organic tonnage chemical that may be produced by the petroleum industry and fermentation. The latter process requires the recovery of acetic acid from water solutions, and several techniques have been applied to this separation, including solvent extraction, azeotropic distillation, and extractive distillation. A comparison of economics between azeotropic distillation and solvent extraction combined with azeotropic distillation (Table 10.3) shows that the introduction of... 

Sc(OTf)3 is more soluble in water than in organic solvents such as dichloromethane. The catalyst can be recovered almost quantitatively from the aqueous layer by simple extraction after the reaction was complete (Sch. 2), and it could be re-used. The recovered catalyst is also effective in the 2nd reaction, and the yield of the 2nd run is comparable with that of the 1st run (Eq. 1) [4], Because Sc(OTf)3 can be successfully recovered and re-used in many other reactions, it is expected to solve severe environmental problems caused by mineral acid- or Lewis acid-promoted reactions in the chemical industry. 

Bromoform is used as a chemical intermediate in the synthesis of organic chemicals and pharmaceuticals. It is used as an ingredient in fire-resistant chemicals and as an industrial solvent in liquid-solvent extractions. Bromoform is used in polymer reactions and in the vulcanization process for rubber. Bromoform is also used for medicinal purposes as a sedative, an-titussive, and antiseptic. 

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