Determination of the condition for the existence of composition minima in a CSTR via spectral analysis

✍ Scribed by D.D. Do; R.G. Rice

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 712 KB
• Volume: 40
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(85)80069-5

✦ Synopsis

Transient response of a CSTR containing porous catalyst pellets is analysed theoretically by a generalized integral transform, and the condition for existence of a minimum in the bulk concentration is determined via the analysis of the eigenspectrum of the governing equations. A simple unikd condition for existence is found to be Vk/F (P$&/E+ p&K) < 1, irrespective of the values of any other parameters, where k is the first order rate constant, Y is the reactor volume excluding pellet volume, F is the volumetric flow rate, pp is the pellet density, Sr is the interior surface arca, E is the pellet voidage and K is the slope of the linear adsorption isotherm. Clearly, the continuous adsorbcr (k = 0) always satisfies this condition, therefore, a minimum in the transient bulk concentration is predicted to always occur. Simulations show that the minimum is sufficiently pronounced and the time scale for the minimum to occur is sufficiently practical that the occurrence of the minimum may be exploited for parameter estimation purposes.