Recovery separation

To describe the varied processes by which alkylphenols are produced, it is convenient to consider the reaction and recovery separately. In some cases this distinction is artificial because the operations are intimately linked, but in many processes the break is operationally significant. 

Pharmaceutical Removal of suspended matter is a frequent application for MF. Processes may be either clarification, in which the main product is a clarified liquid, or solids recovery. Separating cells or their fragments from broth is the most common application. Clarification of the broth in preparation for product recovery is the usual objective, but the primary goal may be recovery of cells. Cross-flow microfiltration competes w l with centrifugation, conventional filtration by rotary vacuum filter or filter press and decantation. MF delivers a cleaner permeate, an uncontaminated, concentrated cell product... 

HPLC offers another significant advantage over GC in terms of the relative ease of sample recovery. Separated fractions are easily collected... 

Collector Dosage (kg ton- ) Product % TiO, Clay % recovery Separation efficiency... 

Various processes separate rare earths from other metal salts. These processes also separate rare earths into specific subgroups. The methods are based on fractional precipitation, selective extraction by nonaqueous solvents, or selective ion exchange. Separation of individual rare earths is the most important step in recovery. Separation may be achieved by ion exchange and solvent extraction techniques. Also, ytterbium may be separated from a mixture of heavy rare earths by reduction with sodium amalgam. In this method, a buffered acidic solution of trivalent heavy rare earths is treated with molten sodium mercury alloy. Ybs+ is reduced and dissolved in the molten alloy. The alloy is treated with hydrochloric acid, after which ytterbium is extracted into the solution. The metal is precipitated as oxalate from solution. 

According to the vendor, liqnid-liquid extraction (LLX) provides recovery, separation, purification, and concentration of metals in one unit process. By use of the proper extractant, metals can be reduced in process or waste streams to the low parts per million (ppm) level. The metals concentrated by the process can often be reused. When appropriate, specific metals can be recovered selectively in the presence of other metals or process stream components. Alternatively, broad-spectrum metal recovery is achievable with the properly selected extractant or process. 

The Met-Tech separation process is a liquid ion exchange process for the ex situ recovery, separation, and concentration of a wide range of heavy metals. The technology is commercially available and, according to the vendor, has been tested at the pilot scale. According to the vendor, future applications will be in soil remediation, acid mine drainage, and the recycling of spent nuclear waste. 

The discussion of green solvents will include chemistry, ecology, and philosophy. The choice of solvents will include new criteria in addition to the traditional considerations of synthesis yield (if we are dealing with reactions), perfect product recovery (separations), or commercial usefulness. 

Deslauriers, L. (2000). Recovery, Separation and Characterization of Phenolic Compounds and Flavonoids from Maple Products. Masters Thesis. McGill University, Montreal, p. 105. 

To optimize processes that are based upon the interaction between microstructure and flow (for example, proppant placement in hydraulic fracture of geologic formations [oil recovery], separations processes for biological materials, mixing and dispersion of additives in blenders, crystal growth and solidification processes). 

Certain of the transplutonium elements are used extensively in nuclear gauges and in many other fields as well. Industrial-scale production of these man-made elements requires development and application of appropriate recovery, separation, and purification processes. 

Campbell, D. O., "The Application of Pressurized Ion Exchange to Separations of Transplutonium Elements," Industrial-Scale Production-Recovery-Separation of Transplutonium Elements Symposium, ACS Second Chemical Congress, Las Vegas, Nevada, 1980. 

The solubilisation of proteins and amino acids in organic solvents by reversed micelles provides a new method for the selective recovery, separation and concentration of bioproducts using liquid->liquid extraction techniques. Selectivity is affected by electrostatic interactions between the charged residues or moieties of the solute and the surfactant headgroups. These interactions are mediated by electrostatic screening as affected by solution ionic strength. The more hydrophobic the amino acid residue, the more favourable is the solubilisation of this residue in the partially structured water pool of the reversed micelle relative to the bulk, unstructured water phase. 

The ability of proteins to transfer from an aqueous solution to a reversed micelle=icontaining organic phase, and be subsequently recovered in a second aqueous phase, was first established by the group of Luisi (2,3). It has since been suggested by van t Riet and Dekker (4, 5) and Goklen and Hatton (6 -9 ) that this phenomenon be exploited in the recovery, separation and concentration of bioproducts from complex aqueous mixtures. In the past three years, significant progress has been made in this direction, and it has been established that these solvents can be selective in the separation of binary and ternary protein mixtures (7f9 ) and in the recovery of an extracellular alkaline protease from a clarified fermentation broth (1 0). It has also been demonstrated that the process can be operated on a continuous basis (5). 

These results on amino acid solubilisation in reversed micelle solutions have indicated clearly that such systems could be useful for the recovery, separation and concentration of small, charged biological molecules from aqueous media. Furthermore, they have shed some light on the role that hydrophobic interactions will play in the solubilisation of more complex molecules such as proteins, which have a distribution of polar and nonpolar amino acid residues over their surfaces. 

In the literature, the thermodynamic advantages of cosolvent addition have been emphasized however, the effect of cosolvents on other aspects of the process, such as mass transfer, overall cost, and product/residue properties, has not been considered in depth. Benefits of cosolvent addition must be balanced against its disadvantages for a specific application. Cosolvent introduction and solvent recovery (separation of the cosolvent from the extract, SCF, and solids residue) increase the complexity of process design. As well, an increase in solvent loading may result... 

Fermentation or Enzymatic Conversion-Recovery-Separation (Bioreactors).397... 

Applications of the OHLM processes are tested mainly in metal separation, wastewater treatment, biotechnologies, drugs recovery-separation, organic compounds, and gas separation. In the recent years, integrated hybrid systems incorporating two or more functions in one module, for example biotransformation and separation, become systems of great interest to researchers. The recent applications of different types of the OHLM systems are summarized below. 

Summary of the Extractants Being Used for Actinide Ions Recovery/Separation by LM-Based Separation Methods... 

This chapter deals with the transport of actinide ions across liquid membranes resulting in their recovery/separation from complex matrices. The transport behavior of lanthanides is also discussed in many places, which has chemical similarity with the trivalent actinides and are often used as their homologs. The transport behavior of actinides/lanthanides across other membranes such as ceramic/metallic and grafted membranes is also included. Table 31.1 gives a summary of the extractants discussed in this chapter. 

Evaporation can be used for a variety of purposes including dehydration, recovery, separation, and concentration. Evaporation is especially useful in the treatment and disposal of specific high-strength, low volume process waste streams. The following industries use evaporation methods on a widespread basis for waste treatment and/or recovery of chemicals ... 

Fermentation or enzymatic conversion-recovery-separation (bioreactors)... 

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