Premium
Kinetics and mass transfer in a fluidized packed‐bed: Catalytic hydrogenation of ethylene
Author(s) -
Farrell Robert J.,
Ziegler Edward N.
Publication year - 1979
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.690250309
Subject(s) - mass transfer , fluidized bed , catalysis , chemistry , packed bed , diffusion , inert , mass transfer coefficient , dimensionless quantity , reaction rate , analytical chemistry (journal) , thermodynamics , chemical engineering , materials science , chromatography , organic chemistry , physics , engineering
The kinetics of ethylene hydrogenation to ethane are studied in a 7.0 cm diameter fluidized packed‐bed reactor. The fixed packing, 1.27 cm nickel on alumina catalyst, is used in conjunction with both −48/+100 mesh alumina and −50/+170 mesh glass inert fluidized particles. Reactant mixture is passed through the reactor at velocities sufficient to fluidize the inerts. Conversions from 0 to 91% are observed over the temperature range 56° to 261°C and flow rate range 10 to 800 cm 3 /s. The mass transfer coefficient and reaction rate constant are simultaneously evaluated from integral conversion data. The mass transfer coefficient between the interstitially fluidized bed and the catalyst surface is correlated in dimensionless form as N sh = 0.77 N Re 0.418 N Sc 1/3 The correlation is significant at the 95% confidence level that is, r = 0.59, p ′ > 0. Predictions of conversion using both the mass transfer coefficient correlation and a Langmuir‐Rideal reaction expression are in good agreement with experimental data. The effects of contact time and catalyst diameter on conversion are also presented. Film diffusion influences become limiting at temperatures above 100°C at the velocities studied. Diffusional resistances were found to be important at Reynolds numbers below 100, at 186°C. No significant difference in reaction rate was found between fluidized alumina and glass inert particles under comparable operating conditions.