Formation and Characteristics of Reaction Intermediates from the Fast Pyrolysis of NaCl- and MgCl 2 -Loaded Celluloses

This study investigates the formation and characteristics of reaction intermediates from the fast pyrolysis of NaCl- and MgCl 2 -loaded celluloses (75–106 μm) at 150–400 °C. The loading of MgCl 2 lowers the onset temperature of cellulose pyrolysis. At low temperatures (e.g., 150 °C), the loading of MgCl 2 increases the yield of water-soluble intermediates and significantly enhances the formation of sugar and anhydro-sugar oligomers. However, the effect of NaCl loading is minimal under the similar conditions. The results suggest that the loading of MgCl 2 catalyzes the cleavage of both hydrogen bonds and glycosidic bonds during cellulose pyrolysis at low temperatures. At increased temperatures (250 °C and above), both the loading of NaCl and the loading of MgCl 2 greatly enhance the destruction of sugar ring structures within the pyrolyzing cellulose. The conversion of water-insoluble solid into water-soluble intermediates, which are important precursors for volatile formation, is reduced significantly, leading to an increase in char yield.