These Catalytic Test Units (CTUs) can be used for many specialty chemical processes, fine chemical and pharmaceutical chemistries, such as: hydrogenation, amination and dehydrochlorination. When used with Applied Catalysts activated carbon monolith catalysts (ACMC®), in addition to process intensification (high productivity), the advantages include: higher selectivity, better thermal management, and low pressure drop/low attrition. Three reactors systems have been designed for catalyst screening. The single catalyst testing unit, the multiple catalyst testing unit, and the catalyst lifetime/recycle reactor testing unit. The CTU systems feature gas phase uptake measurements and differential temperature measurements, which can be used as a first level screen of catalytic activity for hydrogenation and other chemistries where gas phase products are consumed.