Catalytic co-gasification of glycerol/fat mixtures: experimental vs thermodynamic equilibrium results

In this work, the co-gasification of treated crude glycerol and animal fat was studied using steam as the gasification agent. Tests were performed in a downflow fixed bed reactor with a bed composed of catalyst particles of dolomite. The gasification process was studied using a mixture with 59% of glycerol, 3% of fat, and 38% of water and tests were carried out at 700 °C and 750 °C. The producer gas was quantified and analyzed by gas chromatography obtaining, for the tested temperatures, between 48 and 47% of H₂, about 13% of CO, 11% of CH₄, and CO₂ content between 30 and 27%. The results showed that the use of dolomite as a catalyst promotes the production of a gas rich in H₂ and CO₂. The results also show that the gasification parameters increase with temperature. Maximum values of 0.92 m³/kg for dry gas yield, 70.6% for cold gas efficiency, and 58% and 40.9% for carbon and hydrogens efficiencies were obtained. The gasification process was evaluated using the non-stoichiometric chemical equilibrium model. The results obtained showed that the real gasification process does not reach chemical equilibrium.