Plugging time, analytical evaluation

As the apex of the sample plug passed through the sample injection valve, the valve was switched to the inject position for separation and analysis by GC or LC. Evaluation of the overall processing cycle time showed that decreasing the volume of the analytical sample loop from 100 to 10 pL could reduce the overall processing cycle time by up to 5 hours per sample. The product disposition valve could be used to capture a product sample in a vial by directing flow to the fraction collector, to recycle flow back to feed container R, or to direct flow to a weighed product or waste container. 

Differential Method In order to use the differential method of data analysis, it is necessary to differentiate the reactant concentration versus space-time data obtained in a plug-flow PBR. There are three methods of differentiation that are commonly used (i) graphical equal-area differentiation, (ii) numerical differentiation or finite difference formulas, and (iii) polynomial fit to the data followed by analytical differentiation. The aim of differentiation is to obtain point values of the reaction rate ( Ra)p at each reactant concentration Q4 or conversion xa or space time (.W/Fao), as required. All three differentiation methods can introduce some error to the evaluation of -Ra)p- Information on and illustration of the various differentiation techniques are available in the literature [23, 26]. 

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