Catalyst deactivation due to coke formation is an important technological and economic problem in petroleum refining and in the petrochemical industry. Remedies to catalyst deactivation are sought by a variety of strategies involving modification of catalyst surface composition such as the use of polymetallic catalysts and/or by manipulation of the reaction environment which often limits the yield due to thermodynamic constrains (i.e., high hydrogen pressures, etc.). In the limit, when the activity reaches unacceptable limits, regeneration by burning off carbon residues can usually be attained, Regeneration can take place in situ, as in fixed-bed reactors, or in an adjacent reactor to which the catalysts is transported to, such as in moving-bed reactors or in fluidized-bed reactors. In the first case intermittent operation is required, whereas in the second case the operation is continuous, but a second regeneration reactor is required. The choice of the proper process cycle is an economic optimi...

Catalysts deactivation by coking

Science, by its very nature, aspires to the orderly arrangement of knowledge in a way which will allow predictive interpolation and even cautious extrapolation into unstudied regions of performance on the basis of known data. So it is that in the study of kinetics many sophisticated attempts have been made to calculate the rate parameters for some of the simplest gas-phase reactions from basic physical measurements. Most such attempts have so far ended in failure, and kinetics remains basically an experimental science.

K.B. Bischoff

Papers

Kinetic data and product distributions from fixed bed catalytic reactors subject to catalyst fouling