Effects of copper stearate on the premixed combustion and emission performance of jatropha biodiesel

Abstract

Metal-organic complexes can significantly improve the combustion efficiency of fuels and reduce harmful emissions. In this study, the pyrolysis, oxidation, and combustion characteristics of Jatropha biodiesel containing 200 ppm copper stearate were systematically investigated using thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS), spectral analysis, flue gas analysis, high-resolution transmission electron microscopy (HRTEM), and ReaxFF-MD simulations. The results revealed that with the addition of copper stearate, the activation energy (E_a) for pyrolysis and oxidation reactions decreased by 8.04 and 9.40 kJ/mol, respectively. This promoted the generation of C₂ and CH free radicals and increased the OH intensity at the left and middle axial positions of the flame by 66.11 % and 69.56 %, respectively. In addition, the CO, PM2.5, and PM > 10 emissions decreased by 4.0 %, 7.5 %, and 13.2 %, respectively. Further, the average size of soot particles decreased by 3.2 %, and the spacing between polycyclic aromatic hydrocarbons (PAHs) layers increased by 7.2 %. However, the NOx emissions increased by 7.8 %. These findings indicate that copper stearate significantly improves the combustion efficiency of Jatropha biodiesel and reduces the emission of various pollutants, though its impact on NOx emissions should also be considered. Overall, this study provides useful theoretical insights for optimizing biodiesel combustion performance and pollutant control.