are merely illustrative and should not be considered a limitation of the invention as other cross sections regular and irregular and positioning could be employed it is also not a requirement of the present invention that the apertures 38 have the same or similar cross section to the tube 16 passing therethrough 0026 fig4 is a second embodiment of the baffle plate 34 the catalytic reactor 10 is the same as that depicted in fig1 and fig2 except none of the apertures 38 is oversized relative to the tube s 16 passing therethrough instead some apertures 38 have no tube 16 passing therethrough fig5 better shows the distribution of apertures 38 in the plate 35 this embodiment allows greater flexibility as aperture 38 placement is independent of tube s 16 placement these apertures 38 can also be of varying sizes as those skilled in the art of reactor design will appreciate there is a third embodiment of the present invention that is a combination of the first and the second embodiments in other words it is possible to use a combination of apertures without tubes passing therethrough and apertures with tubes passing therethrough that are oversized this embodiment is considered within the scope of the invention referring back to fig2 and 4 the catalyst 42 can be any catalyst composition selected to promote the desired reaction of the first fluid 30 which can either cause an exothermic.