Reaction selectivity in a porous catalyst pellet: Analysis of a kinetic model of two parallel, first order, irreversible reactions with a second order inhibition kinetic term in one of them

Papakonstantopoulos, GD; Androutsopoulos, GP; Philippopoulos, CJ

dc.contributor.author	Papakonstantopoulos, GD	en
dc.contributor.author	Androutsopoulos, GP	en
dc.contributor.author	Philippopoulos, CJ	en
dc.date.accessioned	2014-03-01T01:17:00Z
dc.date.available	2014-03-01T01:17:00Z
dc.date.issued	2001	en
dc.identifier.issn	0009-2509	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14313
dc.subject	Differential Equation	en
dc.subject	Kinetic Model	en
dc.subject	Kinetics	en
dc.subject	Numerical Solution	en
dc.subject	Parametric Study	en
dc.subject	Reaction Rate	en
dc.subject	First Order	en
dc.subject	Second Order	en
dc.subject.classification	Engineering, Chemical	en
dc.subject.other	Catalyst selectivity	en
dc.subject.other	Differential equations	en
dc.subject.other	Pelletizing	en
dc.subject.other	Porous materials	en
dc.subject.other	Pellets	en
dc.subject.other	Catalysts	en
dc.subject.other	catalyst	en
dc.subject.other	chemical reaction	en
dc.subject.other	kinetics	en
dc.title	Reaction selectivity in a porous catalyst pellet: Analysis of a kinetic model of two parallel, first order, irreversible reactions with a second order inhibition kinetic term in one of them	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0009-2509(01)00199-3	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0009-2509(01)00199-3	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	This work deals with the analysis of a kinetic model of two parallel, first order, irreversible reactions that include a second order inhibition term in one of them (i.e. A + b(1)B --> Ck1CA/(1+KCA)2,A + b(2)B --> D-k2CA). The continuity differential equation taking account of isothermal diffusion and reaction of A in a spherical catalyst pellet, was formulated. The numerical solution of the latter equation yielded useful results related to the variation of the effectiveness factor (eta) and the selectivity (S) (S = [k(1)C(A)/(1 + KCA)(2)]/[k(2)C(A) + k(1)C(A)/(1 + KCA)(2)]) for the desired reaction (i.e A + b(1)B --> C) versus the Thiele Modulus (phi). Parametric studies involved the investigation of the effects of k = k(2)/k(1), the ratio of the intrinsic specific reaction rate constants, and the inhibition strength factor (i.e. KCA), upon the eta vs. phi and the S vs. phi curves. The eta vs. phi curve turns faster towards lower eta values for high k values, especially at high inhibition KCA values. Intraparticle diffusion imparts a pronounced effect upon selectivity, a fact contrasting markedly from the standard case of two parallel reactions without inhibition, where selectivity is independent of diffusion resistance. The S vs. phi curves show a step increase occurring at specified values of phi that increase at high inhibition strengths. The relative selectivity S '(= S/S-0) vs. phi curves (where S-0 is the selectivity for reactant concentration at catalyst surface) increases monotonically with k and KCA values and go through a maximum for high phi values. (C) 2001 Elsevier Science Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Chemical Engineering Science	en
dc.identifier.doi	10.1016/S0009-2509(01)00199-3	en
dc.identifier.isi	ISI:000171243400016	en
dc.identifier.volume	56	en
dc.identifier.issue	18	en
dc.identifier.spage	5413	en
dc.identifier.epage	5417	en