Transformation of glucose into added value compounds in a hydrothermal reaction media

In this study, the chemical transformation of glucose into added value products (lactic acid and 5-hydroxymethylfurfural) was analyzed using a hydrothermal reaction medium. A continuous pilot plant that operates up to 400 degrees C, 30 MPa and residence times between 0.004s and 50s was used in order to study the process. The reactions of glucose in hot pressurized water were analyzed at 300 degrees C, 350 degrees C, 385 degrees C and 400 degrees C; the pressure was fixed at 23 MPa and 27 MPa for the experiments. No lactic acid was found at those conditions. High yield of glycolaldehyde (80%, w/w) was found operating at 400 degrees C and 27 MPa with reaction times of 20 s. Two additives (H2O2 and NaOH) were added in different experiments to improve the lactic acid production. The maximum yield of lactic acid was 57% (w/w) carbon basis using NaOH (0.5 M) as catalyst at 27 MPa and 400 degrees C with 20 s of residence time. It was observed that the pH of the medium plays an important role in the selectivity of the process. (C) 2014 Elsevier B.V. All rights reserved.