Thermodynamic Analysis of Autothermal Reforming of Synthetic Crude Glycerol (SCG) for Hydrogen Production

Abstract

This study presents the thermodynamic modelling of hydrogen production from autothermal reforming of synthetic crude glycerol using the Peng-Robinson Stryjek-Vera thermodynamic model and Gibbs free energy minimization approach. In order to simulate the typical crude glycerol, a solution was prepared by mixing glycerol, methanol, soap, and fatty acids. The equilibrium compositions of the reforming gas were obtained and the impacts of the operating temperature, steam to crude glycerol ratio (S/SCG), and oxygen to crude glycerol ratio (O/SCG) on hydrogen production were investigated. Under isothermal conditions, the result showed that maximum hydrogen production is favoured at conditions of high temperatures, high S/SCG, and low O/SCG ratio. However, under thermoneutral conditions where no external heat is supplied to the reformer, results indicate that high hydrogen yield is realised at conditions of high temperatures, high S/SCG and high O/SCG ratio. Furthermore, it was concluded that under thermoneutral condition, steam to SCG ratio of 3.6, oxygen to SCG ratio of 0.75, and adiabatic temperature of 927 K yields maximum hydrogen.

Keywords

• hydrogen
• autothermal reforming
• thermodynamic analysis
• thermoneutral condition