A kinetic study into the styrene hydrogenation over a palladium on alumina catalyst has been made. Styrene was used as a model component for pyrolysis gasoline. A kinetic rate expression has been derived and the inhibiting e6ect of sulfur components has been included. Using this kinetics and mass-transfer models compiled from literature, the performance of two types of reactors for the styrene (pyrolysis gasoline) hydrogenation has been evaluated. A structured reactor such as a monolith has large advantages over a conventional trickle-bedreactor. For the monolithic reactor a more than 3 times higher volumetric productivity is obtainedwith much less catalyst. The modeling results indicate that deactivation by gum formation should be significantly less due to much better hydrogen mass transfer in the reactor.