Aqueous phase reforming (APR) of glycerol over platinum supported on Al2O3 catalyst

Abstract

The glycerol's APR reaction over 5% Pt/Al2O3 catalyst for H2 production in a batch reactor is investigated in the present work. The effect of the operating parameters, such as the: i) reaction time, ii) operating temperature, iii) glycerol concentration and iv) catalyst concentration on: a) the gaseous and liquid products selectivity, b) the glycerol's conversion and c) the H2 yield is investigated. Initially, the glycerol's APR is studied at various temperature (200, 220, 240 °C) and reaction time (30, 60, 120, 240 min), using 1 wt.% or 10 wt.% glycerol solution and 0.5, 1, 2.5 g of 5% Pt/Al2O3 catalyst weight.H2, CO, CH4 and CO2 are mainly detected in the gaseous phase and acetaldehyde, acetone, methanol, ethanol, 1-propanol, acetol, lactic acid, propylene glycol and ethylene glycol, in the liquid one. It is found that the optimum conditions were: 1 g of 5% Pt/Al2O3, 1 wt.% glycerol solution, 240 °C and 4 h of reaction time. Under these conditions the total conversion of glycerol is found to be ~84% (~41% of gaseous and ~39% of liquid products), H2 yield 14.1%, CH4 yield 3.1% and propylene glycol (the main liquid product) yield 25%. It is also found that, for 2.5 g of 5% Pt/Al2O3, 1 wt.% glycerol solution, 240 °C and 4 h of reaction time results the total conversion of glycerol is found to be ~68% (~45% of gaseous and 17% of liquid products), H2 yield 16.5%, CH4 yield 7.4% and propylene glycol yield 8.1%. The increase of catalyst weight leads mostly to gaseous products. © 2015 Elsevier Ltd.