Abstract
The transformation of low cost sugar feedstocks into market chemicals and monomers for existing or novel high performance polymers by chemical catalysis is reviewed. Emphasis is given to industrially relevant, continuous flow, trickle bed processes. Since long-term catalyst stability under hydrothermal conditions is an important issue to be addressed in liquid phase catalysis using carbohydrate feedstocks, we will primarily discuss the results of catalytic performance for prolonged times on stream. In particular, the selective aerobic oxidation of glucose to glucaric acid and the subsequent selective hydrogenation to adipic acid is reviewed. Hydroxymethylfurfural (HMF), which is readily available from fructose, can be upgraded by oxidation to furan dicarboxylic acid (FDCA) or by consecutive reduction and hydrogenolysis to hexanetriol (HTO) followed by hydrogenolysis to biobased hexanediol (HDO). Direct amination of HDO yields biobased hexamethylene diamine (HMDA). Aerobic oxidation of HDO represents an alternative route to biobased adipic acid. HMDA and adipic acid are the monomers required for the production of nylon- 6,6, a major polymer for engineering and fibre applications.
Keywords: Hydrogenolysis, glucaric acid, aerobic oxidation, hydrothermal conditions, polymer, chemical catalysis, adipic acid.