Optimization of Design Parameters

Needless to say that, besides the operating parameters, the geometry and configuration of an SMB plant has a significant influence on the process performance in terms of various objective functions such as the VSP and cross section-specific 

Few published papers deal with the detailed optimization of design parameters. Charton and Nicoud (1995) and Nicoud (1998) have presented a strategy based on a TMB stage model to optimize the operation as well as the design of SMB processes. 

The basic influence of the number of stages and the particle diameter on productivity and eluent consumption is illustrated and compared with batch elution chromatography. Based on this work, Biressi et al. (2000) presented a method to optimize operating parameter and investigate the influence of the particle diameter as well as the feed concentration on process performance. Ludemann-Hombourger, Bailly, and Nicoud (2000a) have also analyzed the influence of particle diameter on the productivity. 

In this contribution the focus will be on the optimization of column geometry for a fixed column distribution first, while the influence of the total number of columns as well as their distribution will then be shown for some examples. A more detailed description of this strategy has been published by Jupke (2004) and Jupke, Epping, and Schmidt-Traub (2002). 

This procedure is repeated until the optimum for the objective function (e.g., VSP, EC, or costs) has been found. 

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The intelligent computer software CyclePad is a very effective tool in design cycles. Any complicated gas cycle can be easily designed and analyzed using CyclePad. Optimization of design parameters of the cycle is demonstrated by the following examples. 

Structure-Control Interaction Modification of Structural ParamMeis, Effects on Performance / Robustness Interaction, Optimization of Design Parameters -- Control Desiyi InvocMgalion Feedfbrwaid / FeeAack, Conlroler Dynamics, AdualDi/Sensor positions... 

These models are designed to define the complex entrance effects and convection phenomena that occur in a reactor and solve the complete equations of heat, mass balance, and momentum. They can be used to optimize the design parameters of a CVD reactor such as susceptor geometry, tilt angle, flow rates, and others. To obtain a complete and thorough analysis, these models should be complemented with experimental observations, such as the flow patterns mentioned above and in situ diagnostic, such as laser Raman spectroscopy. 

Stirring speed, stirring time, and phase ratio. From this data, the stage efficiency in a flow system may be estimated. Optimization of these parameters can result in providing sufficient data for the most economic design... 

No formal optimization of the parameters was attempted. Instead, individual feed, operating, and design parameters were perturbed around a standard set to assess their influence on the computed performance parameters. 

For a given raw material, the composition of the reaction effluents is obviously related to the variables of temperature, residence time, pressure, and steam dilution rate. At the industrial level, the individual optimization of these parameters normally leads to contradictory requirements hence the solution adopted is generally the result of a compromise in the choice of furnace design on the one hand, and operating conditions on the other. However, an attempt is made to express the overall influence of these factors on the performance of the reaction section by means of a representative value that can indicate the degree of severity of the treatment. 

Optimization of all parameters involved, can result in a significant increase of counting rate capability. As an example, results obtained with a test chamber, and carefully designed low noise electronics are shown in Fig. 3, from Ref. An increase of the counting rate of two orders of magnitude has been obtained with an optimized high rate chamber. 

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. 

Through this systematic study, Exelus was able to identify an optimal window of design parameter values that were then used to develop the catalyst. By judicious manipulation of the active material composition, researchers at Exelus developed a unique solid-acid catalytic system that has roughly 400% more active sites than a typical solid-acid catalyst. The catalyst activity was found to be higher than a typical liquid acid catalyst, which means that smaller amounts of catalyst are required, allowing one to design alkylation reactors with significantly lower volumes. 

Key words n-decane dehydrogenation, optimization of reaction parameters, model for n-decene yield, Box-Wilson design... 

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