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Intraparticle diffusion in hydrogenation of 3‐hydroxypropanal
Author(s) -
Zhu X.,
Hofmann H.
Publication year - 1997
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690430220
Subject(s) - hydrogen , diffusion , pellets , chemistry , catalysis , thermodynamics , analytical chemistry (journal) , chemical engineering , materials science , chromatography , organic chemistry , composite material , physics , engineering
Strong intraparticle diffusion resistance was observed and the apparent effectiveness factors were measured for the hydrogenation of 3‐hydroxypropanal (HPA) to 1,3‐propanediol (PD) over Ni/SiO 2 /Al 2 O 3 catalyst pellets at 45 to 80°C and 2.60 to 5.15 MPa in a stirred reactor with a spinning basket. A mathematical model was proposed to describe the intraparticle diffusion and to estimate the effective diffusion coefficients of HPA, PD and hydrogen under reaction conditions by a maximum likelihood function of the apparent effectiveness factors of HPA and PD. The calculated concentration distributions of HPA, PD and hydrogen in catalyst particles reveal an excess of hydrogen at 80°C and higher temperatures, but an excess of HPA at 45°C. It results in a weak dependence of the consumption formation rate of HPA and PD on the partial pressure of hydrogen at high temperature.