An emission characterization study on a model flame fuelled with natural gas and commercial grade propane

Jose J Rodriguez-Henriquez, Christos Keramiotis, George Vourliotakis, Fabian Mauss, Maria Founti

Abstract

Improving combustion efficiency and emission reduction are vital so modern combustors exploit new low temperature combustion concepts and alternative/renewable fuels. Maritime engines increasingly consider their carriers Liquefied Natural Gas (LNG) and Liquefied Petroleum Gas (LPG) among others as fuels. Therefore, an investigation at a fundamental level is needed to recognise the effect of different fuel compositions and to understand the synergistic effects of fuel-engine interactions. Swirling flows ensure effective fuel and air mixing and provide an aerodynamic flame stabilization means for controlling flame shape and size. As a result, engine inlet streams are mixed in such a way to exploit the aforementioned advantages. The current work presents preliminary flame measurements on a laboratory-scale swirl stabilized burner for methane (LNG), propane and commercial propane (LPG) under a constant nominal thermal load. Symmetry axis measurements for all major combustion products and pollutants have been performed on a dry-basis with a continuous Gas Analyser (GA). Detailed speciation measurements have been acquired with a Gas Chromatographer (GC) equipped with a Flame Ionization Detector (FID), for hydrocarbons from C1 to C4. Since Exhaust Gas Recirculation (EGR) and preheating are commonly met in inland heavy duty engines and maritime ones respectively, mixture dilution techniques, at two preheating levels (373 K and 573 K), have been employed in the present work. In all cases, the simulated EGR was formed by Carbon Dioxide, Nitrogen and water in representative ratios. The present work provides a benchmark for comparison and characterization of pollutant concentrations with respect to systematic changes in the fuel stream. The results are discussed towards exploiting the influence of commonly employed engine techniques in a controlled environment.in a controlled environment.