Extraction, commercial processes supercritical fluid

Marentis, R. T. "Steps to Developing a Commercial Supercritical Carbon Dioxide Processing Plant". In Supercritical Fluid Extraction and Chromatography. Charpentier, B. A. Sevenants, M. R., Eds. ACS Symposium Series No. 366 American Chemical Society Washington, DC, 1988 p, 138. 

COMMERCIAL PROCESS. A practical example of a supercritical fluid extraction process is the decaffeination of coffee. Coffee beans are first soaked in water to make the extraction more selective and then are loaded into an extraction vessel through which supercritical CO2 is circulated to dissolve the caffeine. In a separate scrubbing vessel the caffeine is transferred from the CO2 to water, also at high pressure. Extraction is continued until the caffeine content of the beans, originally... 

It should be noted that very little phase behavior data is available for ligands with CO2. Since p-diketones have been shown to be viable for the supercritical fluid extraction of a variety of metals, ranging from transition metals to lanthanides and actinides, we will focus on this set of compounds. In particular, the goal of this research is to determine the binary phase behavior of several P-diketones with CO2 because the phase behavior of the ligand/C02 systems is necessary for the design of in-situ chelation processes. Table I lists the lUPAC and abbreviated names for the p-diketones investigated here. These particular p-diketone ligands were chosen because they could be obtained commercially and have been used in a number of supercritical fluid extraction studies (1-4). 

In the early stages of process development in the U.S., many "promises" were made about the capabilities of, and applications for, supercritical fluid extraction. When the widely-touted applications did not materialize, as exemplified by commercialized processes, for example, the "luster" of supercritical fluid solvents rather quickly faded. It is informative to review some of the trade and association journal articles that were published during this period because of their influence on many researchers and companies in their future investigations of supercritical fluid extraction. 

Not every pharmaceutical will eventually be comminuted by supercritical fluid nucleation, not every polymer processed for molecular weight control by supercritical fluid extraction, not every flavor concentrated by supercritical fluid extraction but some will be. Two applications listed in the table are already in commercial production, and several are in advanced pilot plant development and test market evaltiation. Hops extraction is being carried out by Pfizer, Inc. in its plant in Sydney, NE (33), and General Foods Corporation has constructed a coffee decaffeination... 

The committee also believes that commercially available hazardous waste incinerators should be suitable for final treatment of neutralents, although test burns may be necessary. Some neutralents are high in sodium, which tends to shorten the life of the refractory brick used to line incinerators, but wastes of similar composition have been treated satisfactorily. Commercial hazardous waste facilities are available that offer other technologies that might be better for aqueous wastes. These technologies include biological treatment, supercritical fluid extraction (not to be confused with supercritical water oxidation, discussed later in this chapter) followed by incineration of the smaller volume of extracted organics, and chemically based proprietary processes. 

Nine hazardous waste incinerators that are operating commercially in the United States might be available, two each in Texas and Ohio, and one each in Arkansas, Illinois, Kentucky, Nebraska, and Utah. The largest commercial hazardous aqueous waste treatment facility in the United States is managed by DuPont in Deepwater, New Jersey. It provides a combination of physical, chemical, and biological treatment. Clean Harbors, in Baltimore, uses supercritical fluid extraction to treat aqueous wastes. Perma-Fix, with facilities in the Southeast and Midwest, uses proprietary aqueous treatment processes tailored to specific waste streams. 

The extraction of metals based on a membrane contactor system with conventional solvents is a process widely studied using different configurations, extractants, and extraction solvents. One of the upcoming applications of membrane contactors is supercritical extraction. This process is called porocritical extraction. Porocritical process or porocritical extraction is a commercial supercritical fluid extraction (SFE) technique that utilizes an hollow fiber membrane contactor (HFMC) to contact two phases for the purpose of separation. As an improvement, the extraction of Cu + from aqueous solutions by means of dense gas extraction was achieved by using a hollow fiber membrane contactor device [7]. The authors... 

Several processes utilizing supercritical fluids for materials processing have been reported in the literature although their commercial use is not well documented. Among the well-known processes are rapid expansion of supercritical solutions (RESS) (Phillips and Stella, 1993), the gas antisolvent process (GAS) (Yeo et al., 1993), aerosol solvent extraction system (ASES) (Bleich and Muller, 1996), a precipitation with compressed antisolvent process (PCA) (Brennecke, 1996), and solution-enhanced dispersion by supercritical fluids (SEDS) (Samp et al., 2000). The first four processes are for products that are soluble in the supercritical fluid or in an organic solvent. Biomolecules such as proteins or nucleic acids cannot be dissolved, and for such processes... 

A successful implementation for a commercial application was the erection of a supercritical CO2 extraction plant for roasted sesame oil. This development of a CO2 supercritical fluid extraction process for roasted sesame seeds can serve as an example for the viable production of such special oils. Sesame seeds have a relatively low tocopherol content, but contain other very effective antioxidants that stabilize the oil on the one hand and make it very tasty on the other. Roasted premium sesame oils are very popular in Asia, particularly in Korea and Japan. 

Handmade supercritical fluid extraction (HM-SFE) system enables the extraction in an inexpensive way. The obtained extraction yields and composition is very similar to those obtained by commercial SFE system (Castro-Vargas et al., 2011). Just like a commercial SFE systems, HM-SFE system is composed of various components that need to be in tune to achieve optimal extraction process. In order to balance all the components within a SFE system this paper applies a holistic approach for the problem, where the design is planned as a bottom-up approach (Figure 1). 

Supercritical Extraction. The use of a supercritical fluid such as carbon dioxide as extractant is growing in industrial importance, particularly in the food-related industries. The advantages of supercritical fluids (qv) as extractants include favorable solubiHty and transport properties, and the abiHty to complete an extraction rapidly at moderate temperature. Whereas most of the supercritical extraction processes are soHd—Hquid extractions, some Hquid—Hquid extractions are of commercial interest also. For example, the removal of ethanol from dilute aqueous solutions using Hquid carbon dioxide... 

There is a potential for the commercial application of supercritical CO2 fluid extraction for fractionation of milk fat. However, the differences between the melting properties are not as pronounced as with melt crystallization, thereby limiting the application range of these fractions. Moreover, this process is more expensive than melt crystallization (Bhaskar et al., 1998). Nevertheless, niche applications could be developed if fractions rich... 

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