Parametric study via full factorial design for glycerol supercritical gasification

Abstract

Supercritical water gasification is a promising technology for pollution treatment and syngas production from biomass. The produced gas is composed of hydrogen, carbon dioxide, methane, carbon monoxide and traces of ethane and other light hydrocarbons. This work aims to give a comprehensive experimental study of the supercritical water gasification of glycerol using a full factorial design of experiments (DOE). The effect of five factors, namely: temperature [458 C-542 C], residence time [40-90 min], pressure [23-27MPa], initial concentration of glycerol [10-19wt%] and KOH catalyst quantity [0.60-1.475 wt%], were investigated on several responses such as the gasification efficiency (GE), syngas composition and lower calorific value (LCV) of the produced gas. First order mathematical models correlating each considered response in terms of the considered factors were developed and validated. Also, the significance of the factors effect was validated using analysis of variance. The results showed that the produced gas composition and quality were strongly influenced by temperature and initial concentration. The largest gas production was detected at a temperature of 542 C, a residence time of 40 min, a pressure of 27 MPa, a concentration of 10 wt% glycerol and a KOH catalyst percentage of 1.475 wt%.