1,5-Pentanediol production from 3,4-dihydro-2H-pyran and acetic acid via successive reactions of esterification and hydrogenation

Abstract

1,5-Pentanediol as an important chemical intermediate is commonly used for the manufacture of polyesters and polyurethanes. A novel process was developed for the production of bio-based 1,5-pentanediol (1,5-PDO) from 3,4-dihydro-2H-pyran (DHP) and acetic acid (AA) in this work. The esterification of DHP and AA achieved a 59.8 % DHP conversion and 91.2 % tetrahydropyran-2-yl acetate selectivity (THPOAc) at 373 ​K for 1 ​h and DHP/AA molar ratio of 1 without catalyst. Then the 1,5-PDO with selectivity of 54.5 % was obtained from THPOAc via hydrogenation over Cu/Zn₈/Al catalyst under the conditions of 453 ​K and 50 ​bar. The higher dispersion of Cu nanoparticles, the larger surface area of metallic Cu, the higher amount of Cu⁺ active sites and the lower acidity of Cu/Zn₈/Al catalyst were beneficial for the hydrogenation of THPOAc to 1,5-PDO.