Chemical kinetics for second oxygen addition reactions (·QOOH + O) of long-chain alkanes are of great importance in low-temperature combustion technologies. However, kinetic data for key reactions of ·QOOH + O systems are often difficult to obtain experimentally and are primarily estimated or calculated by using theoretical methods. In this work, barrier heights (BHs), reaction energies (Δs), and relative energies (REs) of stationary points for key reactions of two representative ·QOOH + O systems in the low-temperature oxidation of -butyl as well as pressure-dependent rate constants for the involved reactions are calculated with the high-level quantum chemical method CCSD(T)-F12b/CBS. These results can be employed in the development of low-temperature combustion mechanisms for -butane and longer straight-chain alkanes. In addition, the performance of some quantum chemistry methods with a lower computational cost on BHs, Δs, and REs as well as rate constants is also investigated. Our results indicate that the maximum error on these energies with PNO-LCCSD(T)-F12a is within 1 kcal/mol, and rate constants with this method are in the best agreement with reference values, with a maximum relative error of about half the reference values. Due to its low computational cost and memory requirements, this method is strongly recommended for studying low-temperature combustion reactions involving larger hydrocarbon fuels.
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http://dx.doi.org/10.1021/acs.jpca.4c07506 | DOI Listing |
J Phys Chem A
January 2025
Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
Chemical kinetics for second oxygen addition reactions (·QOOH + O) of long-chain alkanes are of great importance in low-temperature combustion technologies. However, kinetic data for key reactions of ·QOOH + O systems are often difficult to obtain experimentally and are primarily estimated or calculated by using theoretical methods. In this work, barrier heights (BHs), reaction energies (Δs), and relative energies (REs) of stationary points for key reactions of two representative ·QOOH + O systems in the low-temperature oxidation of -butyl as well as pressure-dependent rate constants for the involved reactions are calculated with the high-level quantum chemical method CCSD(T)-F12b/CBS.
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
Department of Environmental Engineering, Faculty of Engineering, Bursa Uludag University, 16059 Nilüfer/Bursa-Türkiye.
This study evaluates atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations in a semi-urban area, Görükle, Turkey, from June 2021 to February 2022. The average concentration of ∑16 PAHs was 24.85 ± 19.
View Article and Find Full Text PDFACS Omega
January 2025
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India.
The current investigation focuses on the copyrolysis of L. (a nonedible oilseed, also known as Nahar) and polyethyelene terephthalate (PET) plastic waste to gain insights into the composition of pyrolysates and the thermal decomposition of complex and mixed feedstocks. The physicochemical properties of the feedstocks were studied through thermogravimetric analysis at a heating rate of 15 °C min, bomb calorimetry, and proximate/ultimate analysis.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran.
In this study, a series of experiments are done to analyze the effect of bluff body geometry on the NO reduction of a natural gas-air stratified swirl burner. The stratified burner of Cambridge University is chosen to study the mentioned geometrical effect, and the geometry modification of bluff body is used as a simple method for NO reduction, which can be easily applied to the systems using these burners, including gas turbines. The bluff body geometrical change to an annular bluff body is inspired by the fact that the areas in which the edge of the bluff body is in contact with the unburned flow have lower temperatures, which can drastically affect combustion parameters, especially emissions.
View Article and Find Full Text PDFWaste Manag
January 2025
Energy and Sustainability Department (EES), Federal University of Santa Catarina (UFSC), 88905-120, Araranguá, SC, Brazil. Electronic address:
Proper waste management and sustainable energy production are crucial for human development. For this purpose, this study evaluates the impact of blending percentage on energy recovery potential and environmental benefits of co-combustion of wastewater sludge and Brazilian low-rank coal. The sludge and coal were characterised in terms of their potential as fuel and co-combustion tests were carried out in a pilot-scale bubbling fluidised bed focused on the influence of the percentage of sludge mixture on the behaviour of co-combustion with coal in terms of flue gas composition and fluidised bed temperature stability.
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