ESCA analysis of partially converted lignocellulosic materials

Further ESCA data of the solid residues obtained by supercritical extraction of Populus tremuloides are reported. The changes of the ESCA spectra with the severity of grinding are discussed. These data allow us to draw precise conclusions on the spatial distribution of carbonaceous recondensed material as thermal conversion proceeds. The C_1s peaks are of special interest as the distribution of the four components in these peaks bears information on the nature of the chemical compounds present on the surface of the sample.