Record Details

Hysteresis and phase transitions in a single partially internally wetted catalyst pellet: Thermogravimetric studies

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Hysteresis and phase transitions in a single partially internally wetted catalyst pellet: Thermogravimetric studies
 
Creator HESSARI, FA
BHATIA, SK
 
Subject multiple steady-states
trickle-bed reactors
porous catalyst
particles
phase transitions
hysteresis
partial internal wetting
hydrogenation
steadystate multiplicity
trickle bed reactors
 
Description The hydrogenation of cyclohexene over palladium supported in a microporous gamma-alumina pellet is studied thermogravimetrically with a view to measuring the extent of partial internal wetting associated with the different steady state branches. As many as three steady state branches having significantly different degrees of internal wetting and reaction rates, with transitions between them, are confirmed from observations of catalyst weight change. It is seen that with reduction in catalyst activity the middle branch, obtained by condensation from a vapor filled pellet, is much more prominent without showing an evaporative transition for the range of hydrogen partial pressures used here. The catalyst activity is therefore an important parameter affecting the structure of the steady state branches. Hysteresis effects are found to occur, and the thermogravimetric results also confirm the importance of history in determining the catalyst state. The measured degree of wetting is in accordance with that estimated from a mathematical model incorporating capillary condensation effects in addition to reaction-diffusion phenomena. The same model also satisfactorily interprets the reaction rate variations and transitions seen in the present work.
 
Publisher GORDON BREACH SCI PUBL LTD
 
Date 2011-07-30T11:05:03Z
2011-12-26T12:52:48Z
2011-12-27T05:39:43Z
2011-07-30T11:05:03Z
2011-12-26T12:52:48Z
2011-12-27T05:39:43Z
1997
 
Type Article
 
Identifier CHEMICAL ENGINEERING COMMUNICATIONS, 157(), 109-133
0098-6445
http://dx.doi.org/10.1080/00986449708936685
http://dspace.library.iitb.ac.in/xmlui/handle/10054/7945
http://hdl.handle.net/10054/7945
 
Language en