Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO_(2) additions

This paper investigated the nanostructure and oxidation reactivity of soot generated from biofuel 2,5-dimethylfuran pyrolysis with different CO_(2) 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 CO_(2) additions was not linear.Compared with 0%,50%,and 100%CO_(2) additions at one fixed temperature,the soot collected from the 10%CO_(2) 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%CO_(2)>100%CO_(2)>50%CO_(2) while the mean particle diameters showed the same order.Furthermore,the oxidation reactivity of different soot samples decreased in the ranking of 50%CO_(2) addition>100%CO_(2) addition>10%CO_(2) 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.