Supercritical Fluid Process Development Studies

Supercritical Fluid Process Development Studies SEPARATION OF ORGANIC-WATER SOLUTIONS Ethanol—Water... 

The WAG process has been used extensively in the field, particularly in connection with supercritical CO injection and some success have been reported.(365-367). However, it would be desirable to develop a method to further reduce the viscosity of injected gas, particularly CO, the most commonly used gas (actually injected as a supercritical fluid) in the U.S.. While limited studies on increasing the viscosity of C0 though the use of supercritical CO -soluble polymers and other additives have been reported (368, see also Chapter 29 and references therein), the major direction of research has been the use of surfactants to form low mobility foams or supercritical C0 dispersions within the formation. 

Supercritical fluid extraction has been focused for the deterpenation of citrus oil as a lower temperature process [1-6]. Coppella and Barton [4], Stahl and Gerard [5], and Temelli et al. [6] studied the extraction process for the removal of terpenes in citrus oil. However, the simple extraction process does not give sufficient selectivity and yield A continuous countercurrent extraction process is one of the method to achieve higher selectivity between terpenes and oxygenated compounds. Perre et al. [7] and Sato et al. [8] succesfully developed the continuous extraction process. 

UV-visible, fluorescence, and IR spectroscopy have been used to characterize the solvent strength of pure and mixed supercritical fluid solvents, and to study solute-solvent interactions. The use of spectroscopic probes for the determination of clustering of pure and binary supercritical fluids about solutes is discussed. Spectroscopic studies of solvent strength and solute-solvent interactions are valuable for the development of molecular thermodynamic theory, engineering models, and for the molecular design of separation and reaction processes. 

The purpose of this study was to develop a general supercritical fluid based process for the separation and purification of pyrrolizidine alkaloids such as monocrotaline (CieHaaNOe, MW=325.3). Monocrotaline was selected as a model because of its role in the development of semisynthetic pyrrolizidine alkaloids (6) and because it occurs in several species of Crotalaria. The seeds of Crotalaria spectabilis served as the source of monocrotaline in this study. 

A broad view of principal findings and processes utilized for the development of oriented polymer morphologies has been presented. New trends toward the advancement of this topic are being developed within the realm of multidisciplinary research. Studies of order development in polymers have—for a few years already—transcended beyond traditional disciplines in chemistry and engineering. Genetically engineered polymers, nanoparticles, self-assembled molecules, supercritical fluids, and hybrids are some of the few areas that are now an integral part of macromolecular structural property relationship studies. 

The potential of supercritical fluids (SCFs) as media suitable to develop new processes for the production of crystals as well as amorphous powders has been outlined and studied since the mid-1980s. 

To date little or no thermodynamic modeling of the phase behavior of the ligand/C02 or metal chelate/C02 systems has been conducted. However, in order for supercritical fluid extraction to be considered as a possible replacement for organic solvent extraction, accurate models must be developed to predict the phase behavior of these systems to allow for both equipment and process design. Equation of state (EOS) modeling was chosen here to model the vapor-liquid equilibrium of the P-diketone/C02 systems studied. Cubic EOSs are the most widely used in modeling high pressure and supercritical fluid systems. This is... 

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