Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO2 additions

This paper investigated the nanostructure and oxidation reactivity of soot generated from biofuel 2,5-dimethylfuran pyrolysis with different CO2 additions and different temperatures in a quartz tube flow reactor. The morphology and nanostructure of soot samples were characterized by a low and a high resolution transmission electron spectroscopy (TEM and HRTEM) and an X-ray diffraction (XRD). The oxidation reactivity of these samples was explored by a thermogravimetric analyzer (TGA). Different soot samples were collected in the tail of the tube. With the increase of temperature, the soot showed a smaller mean particle diameter, a longer fringe length, and a lower fringe tortuosity, as well as a higher degree of graphization. However, the variation of soot nanostructures resulting from different CO2 additions was not linear. Compared with 0%, 50%, and 100% CO2 additions at one fixed temperature, the soot collected from the 10% CO2 addition has the highest degree of graphization and crystallization. At three temperatures of 1173 K, 1223 K, and 1273 K, the mean values of fringe length distribution displayed a ranking of 10% CO2 > 100% CO2 > 50% CO2 while the mean particle diameters showed the same order. Furthermore, the oxidation reactivity of different soot samples decreased in the ranking of 50% CO2 addition > 100% CO2 addition > 10% CO2 addition, which was equal to the ranking of mean values of fringe tortuosity distribution. The result further confirmed the close relationship between soot nanostructure and oxidation reactivity.

Automated summary

This study investigated the nanostructure and oxidation reactivity of soot generated from the pyrolysis of biofuel 2,5-dimethylfuran at different temperatures and with the addition of different levels of CO2 in a quartz tube flow reactor. The results showed that the soot exhibited varying nanostructures based on the temperature and CO2 additions, with the highest degree of graphitization and crystallization observed in the 10% CO2 addition samples. The oxidation reactivity of the soot samples decreased with the increase in CO2 addition, demonstrating a close relationship between soot nanostructure and oxidation reactivity.