Influence of operating variables on the aqueous-phase reforming of glycerol over a Ni/Al coprecipitated catalyst

Abstract A systematic study focused on the aqueous-phase reforming of glycerol has been carried out in order to analyze the influence of several operating variables (system pressure, reaction temperature, glycerol content in feed, liquid feeding rate and catalyst weight/glycerol flow rate ratio) on the gas and liquid products. A continuous flow bench scale installation and a Ni/Al coprecipitated catalyst were employed. The system pressure was varied from 28 to 40 absolute bar, the reaction temperature was analyzed from 495 to 510 K, the glycerol content in the feed was studied from 2 to 10 wt%, the liquid feeding rate was changed from 0.5 to 3.0 mL/min and the catalyst weight/glycerol flow rate ratio varied from 10 to 40 g catalyst min/g glycerol. The main gas products obtained were H 2 , CO 2 and CH 4 , while the main liquid products were 1,2-propanediol, ethylene glycol, acetol and ethanol. A W/m glycerol ratio of 40 g catalyst min/g glycerol, 34 bar, 500 K, 5 wt% glycerol and 1 mL/min, resulted in a high yield to H 2 (6.8%), the highest yield to alkanes (10.7%), the highest 1,2-propanediol yield (0.20 g/g glycerol) and the highest ethylene glycol yield (0.11 g/g glycerol). The highest acetol yield (0.06 g/g glycerol) was obtained at 34 bar, 500 K, 5 wt% glycerol, 20 g catalyst min/g glycerol and 3 mL/min.