The kinetic determination of catalytic Gas/Liquid/Solid (G/L/S) reactions requires to ensure that chemical regime is reached. Before their use, reactors must be characterized par different methods to quantify gas-liquid and liquid-solid transfers. The methods used in the lab are:
 alpha-methylstyrene hydrogenation
 naphtol dissolution
 gas absorption

The kinetics of alpha-methylstyrene hydrogenation has been deeply examined and is now used to characterize G/L mass transfers, namely in micro-structured reactors for which a direct measurement of kLa by gas absorption is not feasible.

Naphtol dissolution in n-heptane has been used to characterize basket-type reactors (Robinson-Mahoney). Naphtol extrudates of the same size than industrial catalysts have been prepared to characterize L/S mass transfer.

Oxygen absorption in water (measured by oxygen probe) and hydrogen absorption in hydrocarbons (pressure decrease measurement) have been used to quantify G/L mass transfers in batch reactors (with or without catalytic basket).