(726f) Catalytic Conversion of Hemicellulosic Biomass to Lactic Acid in Aqueous Phase Media

Xylose, a C5 sugar and the monomer of xylan, is one of the most abundant sugars found in nature. The abundance and ease of isolation of xylose makes it an important potential feedstock for the production of value-added chemicals and fuels. However, xylan and xylose have not been fully utilized in industry nowadays and thus cost-effective conversion processes are imminently needed for fully realizing the potential.  Herein we report here that xylose and xylan can be converted to lactic acid using a heterogeneous catalyst with relatively high yields with water as the reaction media. With presence of a ZrO₂ catalyst, up to 26 % and 16% lactic acid in carbon molar basis was obtained from catalytic conversion of xylose and xylan, respectively, while the process without ZrO2 yields negligible lactic acid production. The catalytic aqueouse-phase processing technique provides a renewable environmentally-friendly way to obtain lactic acid without the use of hazardous reactants. Moreover, among biomass derived carboxylic acids, lactic acid is an important renewable chemical building block for the production of biodegradable plastics and has the potential to replace existing petroleum-based materials.