@misc{EckartShresthaGirietal., author = {Eckart, Sven and Shrestha, Krishna P and Giri, Binod R and Fang, Qilong and Li, Wei and Mauss, Fabian and Krause, Hartmut and Li, Yuyang}, title = {Insight into premixed diethoxymethane flames: Laminar burning velocities, temperatures, and emissions behaviour}, series = {Proceedings of the Combustion Institute}, volume = {40}, journal = {Proceedings of the Combustion Institute}, publisher = {Elsevier}, doi = {10.1016/j.proci.2024.105579}, pages = {1 -- 7}, abstract = {Diethoxymethane ((CH3CH2O)2CH2, DEM) is a promising carbon-neutral fuel. DEM is a diether or acetal with a molecular structure similar to oxymethylene ethers (CH3O-(CH2O)n-CH3, OMEn). Thus, DEM can be expected to have a similar combustion behavior to OMEs, reducing harmful emissions such as NOx and particulate matter (PM) in internal combustion engines. From both experimental and kinetic modeling, fundamental studies on DEM are scarce in the literature. More studies are required to gain a detailed insight into the oxidation kinetics of DEM. Laminar burning velocity (LBV) is a critical property that allows a detailed assessment of the potential application of DEM in combustion devices. Unfortunately, the literature on the LBV of DEM is limited. Therefore, in this study we have investigated the LBV of DEM using two reactors for the first time, namely a heat flux burner and a combustion chamber. The experimental data is reported for equivalence ratio between 0.7 and 1.7, initial temperatures of 368-423 K, and initial pressure of 1-5 bar. In addition, we developed a detailed kinetic model extending our recent work of Shrestha et al. (Combust. Flame. 246 (2022) 112,426) to characterize the combustion behavior of DEM utilizing the new experimental data from this work and the literature data. Our model performs remarkably well in capturing the newly measured LBV experimental data over various experimental conditions. We found that DEM and dimethoxy methane (DMM) have similar values of LBVs (within ±1.5 cm/s) for a given condition, which indicates that intermediate chemistry governs the flame chemistry. Despite DEM being a larger molecule that is expected to have slightly lower LBVs than DMM, its effect on the measured values of LBVs is negligible. Finally, we experimentally measured NOx formation in DEM flame for the first time. The stochiometric flame has the highest NOx formation. The proposed model predicted the equivalence ratio dependence of NOx nicely. However, it overestimates the NOx formation for stoichiometric DEM/air mixtures by ∼30 \%. The model suggests that the thermal NO formation route is favored at lean and stochiometric conditions. In contrast, the prompt NO formation route is enhanced for rich mixtures.}, language = {en} } @misc{EckartShresthaGirietal., author = {Eckart, Sven and Shrestha, Krishna P and Giri, Binod R and Fang, Qilong and Chen, Chen and Li, Wei and Krause, Hartmut and Mauss, Fabian and Liu, Dong and Li, Yuyang}, title = {Chemical insights into ethyl acetate flames from experiment and kinetic modeling: Laminar burning velocity, speciation and NOx emission}, series = {Proceedings of the Combustion Institute}, volume = {40 (2024)}, journal = {Proceedings of the Combustion Institute}, publisher = {Elsevier}, doi = {10.1016/j.proci.2024.105487}, pages = {1 -- 7}, abstract = {Oxygenated fuels, such as alcohols, ethers, and esters, are promising alternatives to conventional fuels. These fuels can help reduce detrimental emissions like carbon monoxide and unburned hydrocarbons and enhance octane ratings. Among these oxygenates, ethyl acetate (EA), a small alkyl ester sourced from biomass, emerges as a clean, promising energy carrier. It serves as a surrogate fuel to facilitate investigations into the combustion behaviours of biodiesel. Despite its importance, the literature knowledge of EA combustion characteristics is limited. Therefore, this study aims to broaden the knowledge of the combustion behaviour of this type of oxygenated fuel compound. In this study, we measured the laminar burning velocities of EA by employing a heat flux burner and a closed combustion vessel over the equivalence ratios of 0.7 - 1.7, pressures of 1 - 10 bar and temperatures ranging from 353 - 423 K. Further, we also measured the NOx emissions in exhaust gas of the premixed flames fueled by EA/air for the first time over the equivalence ratio of 0.8 - 1.2. Additionally, we employed a non-premixed counterflow flame setup for extensive characterisation of species and their concentration under diverse conditions encompassing various strain rates and oxygen concentrations. Finally, we utilized these newly measured data to construct and validate a detailed kinetic model developed as part of this work. The newly developed model will help characterize the combustion properties of EA.}, language = {en} }