Effectiveness Factors for Non-Uniform Catalyst Pellets

Abstract

The catalytic effectiveness factors with variable rate constants and diffusivities were theoretically studied. In this work, the fundamental analysis was undertaken for an isothermal first order reaction on the assumption of linear or hyperbolic rate constant-diffusivity distributions with depth of a flat plate catalyst. The effectiveness factors were correlated as a function of generalized Thiele modulus taking account of the distribution functions, or in terms of apparent rate parameter, ratio of overall rate to rate on external surface, and respective arithmetic mean value of rate constant-diffusivity.

Valorization of olive stones into a granular activated carbon for the removal of Methylene blue in batch and fixed bed modes

“…Hence, this small percentage confirms (with iodine number and Langmuirian type MB isotherms) the microporous behavior of both activated carbons [27]. The surface area accessible to MB is about 12.8% larger for Organosorb 10 GAC than that corresponding to olive stone GAC suggesting a larger mesoporosity for the commercial carbon [28] but adsorption of MB may also depend on the microporous character of the carbon surface as has been reported in the literature [29,30] stating that MB can penetrate in wider micropores (> 1.33 nm) present on the activated carbon, or on its slightly different surface chemistry as shown by Boehm results, pH ZPC values and FTIR spectra on the activated carbons and could be responsible for higher electrostatic interactions on the commercial carbon [31]. This ratio is slightly greater for the Organosorb 10 GAC suggesting that although the porosity was associated with a large part of microporous structure, the presence of carbon-oxygen groups may also have an influence on the adsorbate uptake by providing sites for additional adsorption.…”

A method for the study of performance of a single spherical particle with nonuniform catalytic activity

“…For example, Kasaoka and Sakata ( 1968), Villadsen ( 1976), Corbett and Luss (1974), Shadman-Yazdi and Petersen (1972), and Becker and Wei (1977u, b) have recently developed theoretical models to describe the performance of catalysts with nonuniform activity. Some catalysts contain nonuniform activity as a result of preparation methods employed, while others develop this feature because of poisoning.…”

Effect of a catalyst on the kinetics of reduction of celestite (SrSO4) by active charcoal

“…g of a stoichiometric amount of active charcoal) was mixed (6) In all the experiments, celestite and active charcoal of thoroughly and placed in a silica boat (11-mm diameter and less than 105 m in size were employed for 50-mm long). The sample boat was pushed into the loading experimentation.…”

“…The result of the experiment analysis should be a mirror reflection of the Boudouard reaction. Since the observed conversion-time plot is typically one and is applicable to all cases, even in the presence or absence of catalysts (Kasaoka et al [6] ). The linearized sigmoidal in nature, there should be a definite relationship between celestite reduction & the progress of the Boudouard equation for the MVR model can be written as reaction in the matrix of carbon.…”