Morphological and chemical structure of hydrothermally carbonized saccharides

The research focused on the morphological change and the aromatization of the hydrothermally carbonized saccharides (HCSs) according to the types of saccharide and the treated temperatures. The SEM images showed the fused or individualized spheres by hydrothermal carbonization of the various saccharide types. The saccharides with low molar mass required more complex reaction to be converted into furan. It indicates that the single step conversion gave more chance for the fusion of the resulted spheres, comparing with multi-step conversion to furan. The aromaticity index was adapted to analyze the aromatization degree of HCSs by Raman and FT-IR spectra. The HCSs had the more condensed aromatic structure with higher carbonization temperature regardless the saccharide types.