QUANTITATIVE STUDIES ON FURFURAL AND ORGANIC-ACID FORMATION DURING HYDROTHERMAL, ACIDIC AND ALKALINE-DEGRADATION OF DEUTERIUM-XYLOSE

Chromatographic analysis of the degradation of D-xylose either in plain water or aqueous sulfuric acid at temperatures ranging from 180-220-degrees-C gave up to 50 mol% of furfural. Activation energies did not differ significantly between reactions in plain water (E(a) = 119.4 kJ/mol), 0.001 M H2SO4 (E(a) = 120.6 kJ/mol), 0.01 M H2SO4 (E(a) = 130.8 kJ/mol), and 0.1 M H2SO4 (E(a) = 120.7 kJ/mol). However, under alkaline conditions the activation energy was only 63.7 kJ/mol, indicating a different reaction mechanism. Isotachophoretic analyses revealed the formation of pyruvic, formic, glycolic, lactic, and acetic acid. While the relative yields of these acids ranged from 0.8 to 7% under hydrothermal and acidic conditions, 10 - 23% were obtained in alkaline degradation.