CATALYTIC HYDROTHERMAL CONVERSION OF BIO-DERIVED SUGARS FOR LACTIC ACID PRODUCTION USING SOL-GEL SYNTHESIZED ZIRCONIA

Abstract

The hydrothermal conversion of a multiple sugars solution (xylose, arabinose and glucose) was studied using high surface ZrO2-based catalysts to produce lactic acid. The catalysts were synthesized by template-assisted sol-gel method and alternative template removal procedures. Samples obtained by template extraction with solvent reported a specific surface area of 323 m2/g, a pore volume of 0.21 cm3/g and a total amount of acid sites of 359 µmol/g. An experimental design was performed to model lactic acid and by-products obtaining around the selected catalyst. The response surface methodology (RSM) was used to optimize the main operating conditions. A mass selectivity of 35.1 % towards lactic acid was found at 183 °C and 212 min. In addition, the reaction mechanisms involved were proposed based on intermediates and degradation compounds detected by HPLC analysis.