Diffusion effects in catalytic gas oil cracking

Wojciechowski's four parameter model of catalyst decay is applied to conversion data for gas oil cracking over a diffusion limited catalyst. The parameters thus obtained are compared with those obtained previously for a diffusion free form of the same catalyst, cracking the same feed stock under identical experimental conditions. The comparison shows that the presence of diffusion affects not only the rate of catalytic cracking but also the rate of aging. It is also shown that the introduction of diffusion phenomena has no effect on the mechanism of aging. The presence of diffusion limitations however has the effect of making the feed stock appear more homogeneous in reactivity On peut appliquer le modele de desintegration de catalyseur, a quatre parametres, de Wojciechowski aux resultats de transformation dans le cas du craquage du gasoil sur un catalyseur en presence d'une diffusion limitee. On compare les parametres ainsi obtenus avec ceux qu'on avait trouves anterieurement dans le cas du meme catalyseur en l'absence de diffusion, en procedant au craquage du meme gasoil dans des conditions techniques identiques. On voit que la presence de diffusion affecte non sculement le taux de craquage catalytique, mais aussi la vitesse de vieillissement. On demontre egalement que l'introduction de phenomenes de diffisuion n'a aucun effet sur le mecanisme du vieillissement. La presence d'une diffusion limitee a pour effet, semble-t-il, de produire une reactivite plus homogene du produit d'alimentation.

[1]  Bohdan W. Wojciechowski,et al.  Theoretical interpretation of gas oil conversion data on an x‐sieve catalyst , 1971 .

[2]  B. Wojciechowski,et al.  Catalytic cracking of cumene on aging catalysts: I. The mechanism of the reaction , 1971 .

[3]  V. Weekman,et al.  Kinetics of catalytic cracking selectivity in fixed, moving, and fluid bed reactors , 1970 .

[4]  B. Wojciechowski,et al.  Selectivity of aging catalyst in static, moving and fluidized bed reactors , 1970 .

[5]  Bohdan W. Wojciechowski,et al.  Theoretical patterns of selectivity in aging catalysts with special reference to the catalytic cracking of petroleum , 1969 .

[6]  J. Downie,et al.  A phenomenological classification of catalyst behavior , 1969 .

[7]  Vern W. Weekman,et al.  Kinetics and Dynamics of Catalytic Cracking Selectivity in Fixed-Bed Reactors , 1969 .

[8]  V. Weekman.  Optimum Operation-Regeneration Cycles for Fixed-Bed Catalytic Cracking , 1968 .

[9]  Bohdan W. Wojciechowski,et al.  A theoretical treatment of catalyst decay , 1968 .

[10]  Vern W. Weekman,et al.  Model of Catalytic Cracking Conversion in Fixed, Moving, and Fluid-Bed Reactors , 1968 .

[11]  G. Froment,et al.  Kinetic data and product distributions from fixed bed catalytic reactors subject to catalyst fouling , 1962 .

[12]  G. Froment,et al.  Non-steady state behaviour of fixed bed catalytic reactors due to catalyst fouling , 1961 .

[13]  A. Voorhies,et al.  Carbon Formation in Catalytic Cracking , 1945 .

[14]  D. D. Eley,et al.  The catalysis of the parahydrogen conversion by tungsten , 1941, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.