Flow characteristics of a stack-type microreactor with cylindrical and rectangular pillars were detd. by numerical simulation. In particular, impact of reactor fulfillment on velocity, pressure drop and ay. residence time distribution was taken into consideration. A gas mixt. with compn. corresponding to the stoichiometry of MeOH prodn. by conversion of synthesis gas was used in numerical calcns. carried out by using a corn. computational fluid dynamics software. The effect of filling shape on parameters of the gas mixt. in the reaction zone of micro plaster was evaluated.