The combustion mechanism of biogas mixture is unclear, which leads to the lack of basis for the control of operating parameters. Combustion characteristics and reaction path of typical low calorific value biogas with variation of preheating temperature and air equivalence ratio () are discussed in this paper. Preheating can not only improve the flame propagation speed and flame temperature, but also increase the proportion of NO in the product at the end of combustion flame. To some extent, improving combustion efficiency and NOx control are contradictory operating parameters. The amount of NO increases with the increase in flame distance. The maximum value of NO appears when is 1.1. NO formation rate is improved by preheating the biogas. The paths of N → NO →NO, N → NNH →NO, and N →NO are all enhanced. When the equivalence ratio changes from 1.0 to 0.8, NO formation rates decrease.
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http://dx.doi.org/10.3389/fchem.2021.830329 | DOI Listing |
Environ Pollut
January 2025
Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Applying real-world driving emissions (RDE) data to machine learning, this study investigated vehicular emission characteristics and reduction strategies in Tianjin and Xining, two cities at different altitudes. Significant differences in CO₂ and particulate number (PN) emissions were observed, primarily due to altitude-induced changes in air pressure, affecting air resistance and combustion efficiency. Driving conditions and emission standards were identified as key factors influencing emissions, with road grade and air pressure playing crucial roles at high altitudes.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Management, Sichuan University of Science and Engineering, Zigong 643000, China.
In this work, the coprecipitation approach was successfully used to create Mg-Al hydrotalcite-like inhibitors modified with varying amounts of Zn, and their characteristics were assessed. The findings indicate that the flame retardancy of Mg-Al hydrotalcite (MgAl-LDHs) is not significantly affected by Zn content. By adding MgAl-LDHs, the temperature at which the exothermic reaction started to occur was raised from 146.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Materials Science and Engineering, Hainan University, Haikou 570228, China.
The use of traditional sealing materials in buildings poses a significant risk of fire and noise pollution. To address these issues, we propose a novel composite functional sealant designed to enhance fire safety and sound insulation. The sealant incorporates a unique four-component filler system consisting of carbon nanotubes (CNTs) decorated with layered double hydroxides (LDHs), ammonium dihydrogen phosphate (ADP), and artificial marble waste powder (AMWP), namely CLAA.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.
This study investigates the combustion characteristics and critical thermodynamic conditions for the ignition of TC4 and TC17 alloys under high-speed friction conditions. The results indicate that, under identical rubbing conditions, both the critical pressure and the ignition temperature of the TC17 alloy are higher than those of the TC4 alloy. The critical ignition conditions for both alloys increase with thickness, while they decrease with increasing rotational speed, oxygen concentration, and oxygen pressure.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843, USA.
Ignition of the lubricating fluid in a mechanical system is a highly undesirable and unsafe condition that can arise from the elevated temperatures and pressures to which the lubricant is subjected. It is therefore important to understand the fundamental chemistry behind its ignition to predict and prevent this condition. Lubricating oils, particularly those with a mineral oil base, are very complex mixtures of thousands of hydrocarbons.
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