ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
An analysis is given of the role of physical and chemical forces in determining the selectivity of a solvent for different hydrocarbons. The physical contribution to selectivity depends on the polar energy density of the solvent and on the difference in size of the hydrocarbons to be separated; this effect is well-demonstrated by solvent selectivity data for paraffins where no chemical forces are important. The chemical contribution depends on the ability of the solvent to form acid-base complexes with the hydrocarbon. Chemical forces leading to complex formation can be detected by measurements on the heat of mixing, the volume change of mixing, and on the ultraviolet absorption of solvent-hydrocarbon mixtures; some illustrations of such measurements are presented. Finally an equation is proposed for correlating selectivity data in extractive distillation, and its applicability is demonstrated with activity coefficient data for saturated and unsaturated hydrocarbons in various polar solvents.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690080118
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