Separations Research Program model

A more rigorous prediction of structured mass transfer efficiency is based on results from the University of Texas Separations Research Program (SRP) and the Delft University of Technology, in the Netherlands. Models from these sources have been described and compared in a joint publication and are essentially equivalent. The newer SRP model follows that of Bravo et al., described above, and a brief summary of it follows. 

Bravo, 1. L. Fair, 1. R., Mass Transfer Modeling of Packed Absorbers and Strippers, presented at AlChE Spring Meeting, Orlando, FL, March 1990. Copy available from Separations Research Program, University of Texas at Austin, Austin, TX 78712. 

The development of an hydrodynamic model involves the prediction of pressure drop, hold-up, contact areas between phases, phases ratios and residence time distributions for a given column internal. Although various predictive models are available in the open domain (see e.g. Kooijman and Taylor (2000)), the model developed by The University of Texas Separations Research Program (SRP model) (Rocha et al., 2004, 1996 Fair et al., 2000) enjoys a widespread preference within packed columns internals. Lately, the Delft model has been introduced (Fair et al, 2000) and vahdated for the case of zig-zag triangular flow channels. Note that the following descriptions are referred to a VL system. 

Natalie Cann joined the Department of Chemistry at Queen s in 1997. She is developing a research program focused on the study of separations of mixed systems. In particular, she is using simulations and analytic theories to model simple chiral mixtures. 

A major objective of current research programs in pressure liquefied gas (PLG) safety has been to develop, verify, and validate models for the loss of containment (LOC) failures in partially filled, accidentally heated PLG storage and process vessels, whether for transport or for in on- or offshore situations, e.g., separators, blow-down tanks. 

The experimental results obtained in the laboratory by the researchers can be monitored using computer programs with help of empirical equations or models. Most of the computer-assisted procedures have been developed for HPLC separations and mainly for RPLC, and some of them are commercially available. 

To acquire this information, the two displaced continuum beams are imaged with a cylindrical and a spherical lens onto different positions along the length of the entrance slit of a low dispersion spectrograph (Instruments SA, model UFS-200). The two resulting parallel dispersed spectra are fully separated from each other at the focal plane, where they are detected by the model 1254 SIT detector head of an EG + G Princeton Applied Research Corporation optical multichannel analyzer system. In conjunction with a model 1216 detector controller and model 1215 console, this detector is programmed with a two dimensional... 

Other approaches have been used for more complex models. These include curve stripping or the method of residuals,either manually or using a computer program such as CSTRIP and ESTRIF. These techniques can separate a multiexponential curve into its component parts for initial estimates. Other techniques include deconvolution methods specific to the one and two compartment pharmacokinetic models. The objective of the deconvolution method is to mathematically subtract the results obtained after IV administration from the oral or extravascular data. This results in information about the input or absorption process alone. More general methods have been presented by various researchers that do not rely on a particular compartmental model. ... 

More research efforts are required to address decentralized SCs problems. As previously mentioned, duality, and separability principles may provide frameworks to achieve overall optimal solutions by interchanging among SC partners noncrit-ical information (i.e., dual values) instead of usually confidential data (e.g., costs, prices, technology parameters). Additionally, it would be interesting to explore the use of complementarity programs for decentralized SC modeling. 

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