Clean Oxidation of Alcohols in a Trickle-Bed Reactor with Liquid Flow Modulation

This work reports an experimental investigation of the catalytic oxidation of alcohols, using molecular oxygen as the oxidant and Pt/γ-Al2O3 (1%w/w) as catalyst, in a trickle-bed reactor with ON−OFF liquid flow modulation under mild operating conditions. An aliphatic alcohol (ethanol) and an aromatic one (benzyl alcohol) are used as model reactants. The influence on reactor performance of different variables and modulation parameters (split and cycle period) are examined. Positive and detrimental effects of the liquid flow modulation are found and depend on the reactant used. Long cycle periods generally have a negative influence on the enhancement in conversion attained by using liquid flow modulation. For certain conditions, the enhancement versus cycle period curve shows a maximum, pointing to the importance of a systematic strategy to establish the experimental conditions to be employed if liquid flow modulation will be used. Found experimental trends are interpreted through a recently proposed model at the particle scale.