Commodity Chemicals from Biomass: Conversion of Cellulose into 1,6-Hexanediol

In this presentation, we describe a multi-step catalytic approach for conversion of cellulose into 1,6-hexanediol (C6 α,ω-diol) which is a high-volume (130,000 tons/year), high value ($4,600/ton) commodity chemical. Cellulose is first converted to levoglucosan which is then dehydrated into levoglucosenone (LGO) in the condensed phase with dilute acid (5-20 mM acid concentration) using a polar, aprotic solvent.  The product selectivity is a function of the water concentration, the solvent type and the cellulose loading. Increasing the water content leads to the production of 5-hydroxymethylfurfural. The LGO is then hydrogenated into dihydrolevoglucosenone, levoglucosanol, and tetrahydropyran-2-methanol (THPM).   The THPM then undergoes selective C-O-C hydrogenolysis to produce 1,6-hexanediol using a bifunctional (reducible metal with an oxophilic promoter) catalyst with > 90% selectivity to the desired α,ω-diol. We will discuss how the catalytic properties change the reaction pathways in these various steps and how further improvements in catalyst design could be used to produce these high value commodity chemicals from biomass.