Kinetics of Vacuum Residue Conversion

Catalytic and thermal reactions follow different reaction mechanisms therefore, different reaction orders would be expected. The vacuum residue conversion obtained with catalytic hydrocracking has been properly represented by second-order reaction kinetics (Sanchez and Ancheyta, 2007). Regarding the NHDC reaction, the following expressions can be derived as functions of vacuum residue conversion, kinetic parameters (n reaction order, k kinetic constant), the total mass flow, and the inert material volume  

It is assumed that the reactor follows plug-flow reactor pattern, mass transfer limitations are not present due to the absence of catalyst, and power-law kinetics is considered. For each temperature, the best set of kinetics parameters (n and kj were determined, from which activation energy was calculated to be 42kcal/mol. 

---