Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
EFFECT OF THE CARBON DIOXIDE CONCENTRATION AND THE PREHEATING OF REACTANTS ON THE COMBUSTION OF LOW CALORIFC VALUE BIOGAS MIXTURES
Submission Author:
José Alexandre de Campos , SC
Co-Authors:
José Alexandre de Campos, Roberto Wolf Francisco Jr.
Presenter: José Alexandre de Campos
doi://10.26678/ABCM.COBEM2021.COB2021-1430
Abstract
Syngas and biogas are renewable fuels that have a minor impact over the environment, when compared to fossil fuels. Syngas are usually composed by CH4, CO, H2, and CO2, depending on the raw material utilized in the gasification processes. Instead, biogas is produced by the anaerobic action of bacteria over biological waste and is composed mainly of CH4 and CO2, with traces of other gases. However, the composition of biogas can vary continuously during the production process, sometimes more abruptly and making it difficult to use it in conventional burners. Thus, the objective of this study is to evaluate the effect of the biogas composition and the preheating of the reactant’s mixtures on the flame stability range, reaction temperature and pollutant emission. The biogas used is compost by CH4 and CO2. The maximum concentration of CO2 present in the fuel mixture, keeping the stable flame, will be determined experimentally, using a porous radiant burner. This type of burner was chosen for the present study due to the heat recirculation inside the porous matrix, which allows to achieve higher combustion rates and high reaction temperatures. Preliminary results using pure methane resulted in an equivalence ratio range between 0.45 and 0.55, for the reactants temperature at 300 K and pressure at 1 atm. The maximum equivalence ratio is limited by the degradation temperature of the porous ceramic used to build the burner (~1673 K). For the equivalence ratio equal to 0.45, the maximum thermal power obtained was 1.6 kW. This work continues with the addition of CO2 in the fuel mixture and the preheating of the reagents to 400 K. For the preheating of the reactants, is expected to achieve a stable flame for biogas mixtures with higher concentration levels of CO2 on its content.
Keywords
Biogas, Porous radiant burner, reactants preheating
