Biomass-derived levulinic acid as a platform chemical for making diverse products

This review is concerned with the production of levulinic acid (4-oxopentanoic acid; CH3C(O)C2H4C(O)OH) from lignocellulosic biomass, and its use as a platform chemical for making other chemical products. In principle, levulinic acid can be made from many carbohydrate feedstocks; however, the focus here is on the oil palm empty fruit bunch fiber as the main feedstock. Levulinic acid production from this feedstock is compared with production from some of the other common biomass feedstocks. Levulinic acid is a precursor for diverse other useful chemicals including solvents, plastics, agrochemicals, fragrances, and plasticizers. Direct transformation of levulinic acid into multiple value-added chemicals using several different types of chemical reactions is discussed. The reactions covered include hydrogenation, oxidation, esterification, condensation, and multi-step syntheses. The conversion of levulinic acid, and the yield of the desired products from the various reaction schemes, are compared. Recommendations are made for enhancing the levulinic acid conversion to the sought products.