New catalytic strategies for alpha-omega diol production from lignocellulosic biomass
Catalytic strategies for the synthesis of 1,5-pentanediol (PDO) with 71% yield from hemicellulose and synthesis of 1,6-hexanediol (HDO) with 29% yield from cellulose are presented. Fractionation of lignocellulosic biomass (white birch wood chips) in gamma-valerolactone (GVL)/H2O generates a pure cellulose solid and liquid stream containing hemicellulose and lignin, which is further dehydrated to furfural with 85% yield. Furfural is converted to PDO with sequential dehydration/hydration, ring-opening tautomerization, and hydrogenation reactions. Acid-catalyzed cellulose dehydration in tetrahydrofuran (THF)/H2O produces a mixture of levoglucosenone (LGO) and 5-hydroxymethylfurfural (HMF), which are converted with hydrogen to tetrahydrofuran-dimethanol (THFDM). HDO is then obtained from hydrogenolysis of THFDM. A techno-economic analyses demonstrate that this approach can produce HDO and PDO at a minimum selling price of $4,090.