Optimization of Operating Parameters

The operating point of an SMB unit is characterized by the flow rates of the liquid phase in the four sections, Vj, as well as the switching time, tshift. Another degree of freedom is the concentration of the solute in the feed stream - but according to Charton and Nicoud (1995) the feed concentration should be at its maximum to achieve best productivity. For the following considerations feed concentrations as well as temperatures are kept constant. 

To achieve 100% purity for both components it is necessary to fulfill the constraints mentioned before. In addition, it is favorable to push the fronts as far as possible toward points 1-4 to realize the highest throughput as well as the lowest eluent consumption. 

If product purities lower than 100% are required, there are generally two possibilities to achieve this with a positive impact on other process parameters  

In these cases the raffinate will be polluted with the more strongly retained solute A and/or the extract will be polluted with the less retained component B. Depending on purity requirements and the objective function, any combination of these two cases can also be chosen. 

Whenever dealing with the operation of SMB units one always has to consider the time the process needs to reach its periodic steady state. Depending on the chromatographic system, the process setup, and the column geometry it might take 15 or more complete cycles to reach steady state. 

The fundamental function of atomizers in AAS is simply to produce atoms. The basic steps carried out continuously in flame atomization are (i) Nebulization (conversion of sample into droplets leaving small particles) (ii) Desolvation (removal of solvent) (iii) Atomization (thermal or chemical breakdown of solid particles) (iv) Measurement (interaction with radiation)  

A number of instrumental parameters will affect precision and sensitivity in these atomization techniques. In both systems, bandpass (slitwidth) and lamp current must be optimized. In flame AAS, the other operating parameters are burner height,burner alignment, fuel flow, flame, type, and 

In the electrothermal AAS system each step in the temperature programme of the graphite furnace must be optimized. Each stage requires different temperatures, times, and ramp-rates depending on the analyte and the sample matrix. 

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Kadjo, A. J. J., Brault, R, Caillard, A., Coutanceau, C., Gamier, J. R, and Martemianov, S. Improvement of proton exchange membrane fuel cell electrical performance by optimization of operating parameters and electrodes preparation. Journal of Power Sources 2007 172 613-622. 

P Hayes, MR Smyth, I McMurrough. Comparison of electrochemical and ultraviolet detection methods in high-performance liquid chromatography for the determination of phenolic compounds commonly found in beers. Part 1. Optimization of operating parameters. Analyst 112 1197-1203, 1987. 

Jeyasingh, J. and Philip, L. 2005. Bioremediation of chromium contaminated soil Optimization of operating parameters under laboratory conditions. Journal of Hazardous Materials, B118 113-20. 

Tetrafluorochloroethane (HCFC-124 CF3CHCIF) is a potential replacement in refrigeration and solvent applications, either as a pure compound or as a component of a blend or azeotrope. Several of the methods and catalytic systems discussed in Section II,B have been applied for the synthesis of HCFC-124. Research focus has been on optimization of operational parameters and also the development of specific catalysts for product maximization. In addition, one can also use HCFC-123 as a starting material or a pentahaloethane instead of PCE. Manzer and Rao (65) have reported that a cobalt salt on alumina, which is fluorided prior to use, is an effective catalyst for the conversion of pentahaloethanes to HCFC-123 and... 

Devay, A. Uderszky, J. Racz, I. Optimization of operational parameters in fluidized bed granulation of effervescent pharmaceutical preparations. Acta Pharm. Technol. 1984, 30, 239-242. 

This chapter proposes a strategy that should be suitable for many separation problems. The following strategy should also be suitable for the optimization of operating parameters of an existing plant as well as the design of a new column ... 

This section presents a systematic strategy for the optimization of operating parameters, based on the transport-dispersive SMB model (Chapter 6.7). A first approximation is performed by applying the triangle theory described above. Notably, the basic strategy of this procedure is not limited to a model-based design but can also be applied for the experimental optimization of a running separation process. 

Figure 7.25 Strategy for the optimization of operating parameters. (Reproduced from Jupke et al., 2002.)...

Phillips, M. W. Subramanian, G. Cramer, S. M. "Theoretical optimization of operating parameters in nonideal displacement chromatography" J. Chromatography. 1988, 454, pp 1-21. 

Force-field programming commonly is used in the SdFFF characterization of many colloidal particles to ensure that the entire particle-size distribution can be described in a convenient analysis time (10, 15). Constant force-field operation provides for the highest resolution of particles in the sample, with resulting highest precision. However, this mode of operation does not permit the rapid optimization of operating parameters for analyzing many samples. Also, characterization of samples with wide particle-size distributions is difficult with constant force-field operation. Force-field programming removes these limitations and provides a convenient and practical compromise for most applications. 

In the classification scheme in Sec. 1.4.1, the first three entries under liquid-solid separation methods, i.e., ion-exchange, adsoiption, and sorbent extraction, all belong to column separation techniques. While in the batch approach, separations based on these principles may be performed either by static equilibration or by a column technique, online columns are invariably used in FI separations, both for convenience and efficiency. FI column separation systems based on different sorptive mechanisms do not differ strongly in the principles of system design and optimization of operational parameters. Therefore, the principles discussed in the following sections are generally applicable to the different approaches. 

Tyihak, E. Mincsovics, E. Kalasz, H. Nagy, J. Optimization of operating parameters in overpressured thin-layer chromatography. J. Chromatogr. 1981, 211, 45. 

Powdered bone wet-ashed with hot HNO3 and H2O2. Simplex optimization of operating parameters. Elements of group B determined after concentration on poly(dithiocarbamate) resin. 

Huang W, Li Z, Niu H, Li D, Zhang J (2008) Optimization of operating parameters for supercritical carbon dioxide extraction of lycopene by response surface methodology. J Food Eng 89 298-302... 

Arico AS, Creti P, Antonucci PL, Cho J, Kim H, Antonucci V. Optimization of operating parameters of a direct methanol fuel cell and physico-chemical investigation of catalyst-electrolyte interface. Eleetrochim Acta 1998 43 3719-29. 

Attama AA, Adikwu MU, Esimone CO. Binary combination of detarium gum and vee-gum as a binder in sodium salicylate tablets. Bole Chim Farm 1999 138 199 202. Soyeux P, Delacourte A, Delie B, Lefevre P, Boniface B. Influence of optimization of operating parameters with a new binder in wet granulation. I use in powder form. Eur J Pharm Biopharm 1998 46 95-103. 

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