关键词:

5-羟甲基糠醛, 乙酰丙酸, 稀硫酸, 降解, 动力学

Abstract:

The decarboxylation of 5-hydroxymethylfurfural to levulinic acid is a key step in the preparation of levulinic acid from biomass.In order to study the feasibility of producing levulinic acid by hydrolyzing biomass with dilute sulfuric acid, the decomposition kinetics of 5-hydroxymethylfurfural was systematically investigated at initial 5-hydroxymethylfurfural concentration of 1—9 mg·ml^-1, sulfuric acid concentration of 0.05%—0.4%(mass) and temperature from 150℃ to 190℃.A parallel reaction mechanism was proposed to data reduction, in which the main reaction was to form levulinic acid and the side reaction was to form undesirable humins.With the first-order kinetics equations, the activation energies evaluated were 78.5 kJ·mol^-1, 98.0 kJ·mol^-1 and the reaction orders to H⁺ concentration were 1.16, 0.722 for main and side reactions respectively under the experimental conditions.The results indicated that the selectivity of levulinic acid could be improved at a lower reaction temperature and a higher sulfuric acid concentration.

Key words:

5-羟甲基糠醛, 乙酰丙酸, 稀硫酸, 降解, 动力学