Liquid-liquid extraction using solvent mixtures with a critical point of miscibility.
Item
-
Title
-
Liquid-liquid extraction using solvent mixtures with a critical point of miscibility.
-
Identifier
-
AAI9315510
-
identifier
-
9315510
-
Creator
-
Ullmann, Amos.
-
Contributor
-
Adviser: Reuel Shinnar
-
Date
-
1993
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Engineering, Chemical
-
Abstract
-
The isolation and purification of solutes by a novel type of separation, the Phase Transition Extraction (PTE) process, has been developed and studied.;The main idea underlying the PTE process is based on the use of solvents that have a critical point of miscibility. By manipulating the temperature of such solvents across the coexistence curve one can alternately create regions where either the solvents form a homogeneous solution or they separate into two distinct phases. Hence, the mixing and settling sections of the conventional extraction equipment are replaced in the PTE process by heated and cooled sections.;The formation of a single phase in the mixing section results in a substantially superior contact between the solvents, eliminating the need for intense agitation.;The continuous change in the composition of the phases during the phase separation process prevents the formation of stable interface on which solids or emulsion-forming impurities can adhere. Consequently, the coalescence process is very fast, and the process is not sensitive to the presence of impurities or emulsifiers.;The PTE process allows high efficiency extraction in emulsion forming systems such as fermentation broth without the use of pre-filters, emulsion-breakers, or centrifuges. Moreover, since a high stage-efficiency can be obtained in the PTE process with a minimal or without any mechanical mixing, the degradation of shear sensitive compounds is avoided.;Operating the PTE process in a column with no moving parts incorporates the simplicity of non-agitated columns with the high efficiency of agitated columns. This makes the PTE column an attractive tool for separations that require a large number of theoretical stages. In addition, moving parts, bearing and the like, which are subjected to mechanical wear, can be eliminated. The ability to effectively seal the equipment is particular important in handling of irradiate compounds where remote operation, low maintenance, and heavy shielding are required.;The above features of the PTE process could allow for separation processes which are at present economically not feasible or difficult to carry out.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
