Catalytic Transformation of Biomass-Derived Hemicellulose Sugars by the One-Pot Method into Oxalic, Lactic, and Levulinic Acids Using a Homogeneous H2SO4 Catalyst

Abstract

This article presents the conditions for the conversion of hemicellulose with different contents of C6 and C5 carbohydrates and uronic acids based on the OrganoCat process, and the abbreviations M1, M2, and M3 are used. Homogenous catalysis with sulfuric acid (VI) in the concentration range of 0.1–1 M was used in the study to determine its activity on the ability to transform a hemicellulose mixture. The process was carried out using the one-pot technique in the temperature range of 100–250 °C for 1–5 h. Based on the use of the chromatographic technique (HPLC-RID) together with a comparison with standard substances, the resulting chemical compounds were determined and identified from the post-reaction mixtures. The degree of covalence of the raw material, the selectivity of the obtained chemical compounds, and the yield of lactic acid were also determined. Based on the obtained results, lactic acid with the highest yield (64.57%) was obtained after 1 h of the process from the M1 mixture at the temperature of 100 °C with 0.1 M sulfuric acid (VI) as a catalyst. The formation of oxalic acid was also observed, which is present in all post-reaction mixtures, regardless of the composition of the raw material, temperature, and time. Its efficiency was determined at an average level of 90%.