AI Summary & Key Takeaways
AI InsightThe results show that the sum of specific thermo-mechanical and chemical exergy of combustion products has a decreasing trend with increasing CO2 content in biogas.
📌 3 Key Takeaways
Abstract
This work presents the exergetic evaluations of the oxy-biogas combustion process in an adiabatic furnace for the cases of biogas involving different carbon dioxide (CO2) concentrations. A three-dimensional steady-state computational fluid dynamics model was developed for combustion simulation. The model was first verified with the data of oxy-natural gas and showed good agreement with the data. Thus, simulation studies were performed for the oxy-biogas combustion with different CO2 concentrations of biogas fuel, from 10 vol% to 40 vol% with a 10% increment, at a constant input power capacity. The results show that the sum of specific thermo-mechanical and chemical exergy of combustion products has a decreasing trend with increasing CO2 content in biogas. However, the exergy flow rates of the combustion products increased with the increase in CO2 due to the increasing mass flow rates. Increasing the CO2 level in biogas led to an increase in the chemical exergy fraction of the combustion products. Thus, the exergy loss fractions resulting from incomplete combustion varied increasingly from 5.8 % to 13.8 % in the range from 10 % CO2 to 40 % CO2 contents of biogas.