A heterogeneous, perfectly stirred catalytic reactor with internal recirculation, with the catalyst placed in a fixed bed, was developed in order to characterize several catalysts employed in ammonia industry. For carbon-dioxide methanation on an Ni/Al2O3 catalyst, the perfect mixing was obtained at a stirrer rotation speed of 1000-2600 rpm, which ensured the same reaction rate, regardless of composition and feeding gas flow rate.