TY - GEN A1 - Giri, Binod Raj A1 - Mai, Tam V.‐T. A1 - Shrestha, Krishna Prasad A1 - Giri, Sushant A1 - Naik, R. Thirumaleswara A1 - Verma, Rakhi A1 - Mauss, Fabian A1 - Huynh, Lam K. T1 - Theoretical kinetic study of NH₂ reactions with dimethyl ether and diethyl ether : implications for kinetic modeling T2 - International journal of chemical kinetics N2 - Ammonia (NH₃) and hydrogen (H₂) have emerged as promising carbon‐free fuels to help mitigate global warming by reducing greenhouse gas emissions. Our ongoing research currently focuses on understanding the combustion characteristics of NH₃ blends with oxygenates and hydrocarbons, uncovering the critical role of carbon–nitrogen cross‐reactions in accurately modeling their combustion behavior. Amino (NH₂) radicals, which are abundant in ammonia and nitrogen‐rich environments, strongly influence the low‐temperature reactivity of NH₃‐hydrocarbon/oxygenate mixtures, affecting overall reactivity and emission characteristics. Recognizing the importance of NH₂ radicals, we investigated the reaction kinetics of NH₂ with dimethyl ether (DME, CH₃OCH₃) and diethyl ether (DEE, CH₃CH₂OCH₂CH₃) using appropriate high‐level ab initio and statistical rate theory methods. We computed the potential energy profiles at the CCSD(T)/cc‐pV(T, Q)Z//M06‐2X/aug‐cc‐pVTZ level of theory, analyzing the reactivity of NH₂ radicals at various C─H sites of these diethers. Incorporating these newly derived rate parameters, our updated kinetic model successfully captures previous experimental data, addressing the modeling challenges encountered in our earlier studies. Our findings, including insights into the impact of NH₂ radicals, contribute to an understanding of ammonia combustion and its potential in achieving carbon‐neutral energy systems. KW - Diethyl ether KW - Dimethyl ether KW - Kinetic modeling KW - NH Y1 - 2025 U6 - https://doi.org/10.1002/kin.21779 SN - 0538-8066 SN - 1097-4601 VL - 57 IS - 6 SP - 353 EP - 363 PB - Wiley CY - Hoboken, NJ ER - TY - GEN A1 - Shrestha, Krishna Prasad A1 - Giri, Binod Raj A1 - Pelé, Ronan A1 - Aljohani, Khalid A1 - Brequigny, Pierre A1 - Mauss, Fabian A1 - Halter, Fabien A1 - Huynh, Lam K. A1 - Mounaïm-Rousselle, Christine T1 - A comprehensive chemical kinetic modeling and experimental study of NH₃−methanol/ethanol combustion towards net-zero CO₂ emissions T2 - Combustion and flame N2 - Ammonia is gaining attention as a green fuel with the potential to reduce carbon emissions. Its versatility allows it to be used directly in combustion engines, fuel cells, and as a hydrogen carrier, making it a key candidate for sustainable energy applications. This study provides a comprehensive analysis of the oxidation kinetics of ammonia (NH3) blends with methanol (CH3OH) and ethanol (C2H5OH) under diverse conditions. We measured laminar flame speeds of different NH3-alcohol blends — varying CH3OH/C2H5OH ratios (0–100 %) — using a constant volume combustion chamber across temperatures from 503 to 645 K and pressures of 2–11.3 bar. We also obtained the ignition delay times for NH3/C2H5OH blends with 10 % and 30 % (by mole) C2H5OH using a shock tube at pressures of 1, 10, and 20 bar and temperatures of 1100–1500 K. Our results show that incorporating CH3OH and C2H5OH into NH3 increases the laminar flame speed, with C2H5OH being a more effective promoter than CH3OH due to its higher contribution to the formation of reactive radicals (OH, H, and O). Our model suggests that at high temperatures, both CH3OH and C2H5OH contribute to increased NO formation, with C2H5OH being more effective in reducing N2O emissions than CH3OH. In shock tube experiments, adding C2H5OH significantly shortens ignition delay times of NH3. At low temperatures (in the rapid compression machine case), the sensitivity to ignition delay times decreases when the CH3OH/C2H5OH content exceeds 5 % in NH3-alcohol blends. C2H5OH is a more effective combustion promoter, enhancing NH3 reactivity and reducing NOx emission more efficiently than CH3OH. We developed a detailed kinetic model, building on our previous work, and validated it against new experimental and literature data. Our model accurately predicts the combustion behavior of neat NH3 and NH3 fuel blends and serves as a base for future research on NH3 blended with higher hydrocarbons and/or oxygenated blends. KW - Ammonia KW - Methanol KW - Ethanol KW - Kinetic modeling KW - Laminar flame speed KW - Ignition delay time Y1 - 2025 U6 - https://doi.org/10.1016/j.combustflame.2024.113954 SN - 0010-2180 VL - 274 SP - 1 EP - 21 PB - Elsevier BV CY - Amsterdam ER -