Crude bio-glycerol aqueous phase reforming and hydrogenolysis over commercial SiO2[sbnd]Al2O3 nickel catalyst

Abstract

In the present work, an one-pot Aqueous Phase Reforming (APR) and Aqueous Phase Hydrogenolysis (APH) of crude glycerol in a batch reactor containing commercial SiO2Al2O3 supported 65%Ni catalyst is performed. The effect of: i) the glycerol’s impurities, ii) the operating temperature (200–240 °C) and iii) the crude glycerol concentration (10–40 wt%) is investigated.The main gaseous products are H2, CH4 and CO2, while the main liquid products are propylene glycol (PG), ethylene glycol (EG), ethanol and acetol. The selectivities of the gaseous and liquid products are not strongly affected by the addition of low concentration impurities of methanol and sodium chloride. Glycerol’s conversion increases as temperature and glycerol’s concentration increases. Total conversion for both pure and crude glycerol is >90%. The yield of the most useful liquid product (propylene glycol) is reaching up to 30% for a 40 wt% of crude glycerol solution at T = 240 °C and 4 h of reaction time.