화학공학소재연구정보센터
Catalysis Today, Vol.358, 149-154, 2020
Selective production of dihydroxyacetone and glyceraldehyde by photo- assisted oxidation of glycerol
Glycerol is a by-product during biodiesel production and represents a potential low-cost raw material for obtaining high-cost products like Dihydroxyacetone (DHA) and glyceraldehyde (GCD) amongst others. In this work, Fe-Pillared clay (Fe-PILC) was assessed as catalyst of the selective photo-oxidation of glycerol to obtain DHA and GCD at moderate conditions (298 K and atmospheric pressure). This was conducted in a 100 mL Pyrex glass batch reactor where a Pen-Ray lamp of mercury of 5.5W UV light (UVP) was placed at the centre. The FePILC was prepared by ion exchange. The pillaring was confirmed by XRD, and a 17% w/w of Fe was determined by Atomic Absorption Spectroscopy. The active phases were established by XPS and found to be FeO and Fe3O4. The specific surface area of the clay (bentonite), determined by N-2 physisorption, increased from 34m(2)/g to 227 m(2)/g and the pore volume increased from 0.058 cm(3)/g to 0.106 cm3/g. The studied variables were catalyst loading and glycerol initial concentration. An experiment with TiO2 Degussa P25 was also performed as reference. It was found that by adding Fe-PILC to the glycerol oxidation system, selectivity towards DHA or GCD can be tuned. A selectivity towards DHA was found to be 87% with 0.1 g/L of Fe-Pillared after 8 h reaction. The in situ production of H2O2 was observed and therefore concluded that the glycerol oxidation occurs via a fenton process, i.e. via free radicals.