Kinetic analysis of the conversion of aqueous erythritol solution on Ir/ReOx/TiO2 in a batch slurry reactor

The influence of temperature, H2 pressure and erythritol concentration on the hydrogenolysis of erythritol was studied using Ir/ReOx/TiO2. Under the conditions used here, four reaction routes coexist: isomerization, dehydration, C-O and C-C hydrogenolysis. The initial rates as well as reaction orders and activation energy were estimated for each pathway. The variation of the hydrogen pressure produced slight changes in the isomerization, dehydration, and C-C hydrogenolysis routes, whereas C-O hydrogenolysis showed order 1 with respect to this reagent. The change in erythritol concentration affected more the dehydration, resulting in a reaction order for this reactant close to 1, while for the other routes the order was close to 0.5. Regarding the influence of the temperature, dehydration of erythritol showed the highest activation energy (212.1 kJ mol−1) and the isomerization the lowest (20.0 kJ mol−1). Furthermore, it was found that the ruptures of C-C bonds require higher energy than C-O bonds break.