Numerical Investigation of Combustion and Emission Behavior of Shale Gas Mixtures in a Laboratory Scale Combustor

In this study, effects of gas composition and swirl number on combustion and emission behavior of shale gas mixtures were numerically investigated in a laboratory scale combustor. For this purpose, a two-dimensional model of an experimentally tested premixed combustor was formed. In this model, methane/air combustion was simulated, and achieved results were compared with experimental data to validate applicability of the model. Numerical studies were performed using computational fluid dynamics software, ANSYS/Fluent. Tested shale gas mixtures are; 86% CH4 - 14% C2H6, 81% CH4 - 10% C2H6 - 9% N2 and 58% CH4 - 20% C2H6 - 12% C3H8 - 10% CO2. Combustion and emission behavior of the respective mixtures were determined by examining temperature and species (CO2 and NOx) distributions throughout the combustion chamber. Results of this study showed that %86 CH4- %14 C2H6 mixture is favorable in terms of combustion and emission performance; emissions of NOx are highly dependent on gas composition and swirl number, and axial temperature values and reaction rate are directly proportional to swirl number.