A Novel Pathway to 1,5-Pentanediol without the Use of Noble Metals

Recent focus in biomass conversion has shifted from the production of low value fuels to high value chemicals. α,ω-diols are important chemicals for their uses as polyurethane precursors, resins, and plasticizers. The petroleum industry produces 138 and 2,500 kilotons/year of 1,6-hexanediol and 1,4-butanediol, respectively. This market size and a projected market growth rate of 8% per year allow for additional production from biorenewable sources without market saturation [1,2].

We have developed a new route to synthesize 1,5-pentanediol in high yields from the hemicellulose fraction of lignocellulosic biomass. Previous work focused on direct hydrogenolysis of the fully hydrogenated form of furfural, tetrahydrofurfuryl alcohol, to 1,5-pentanediol with RhRe catalysts [3,4]. Our new multi-step process uses a combination of heterogeneous acids and supported base metal catalysts. The ability to use base metal catalysts stems from the improved reactivity of a key reaction intermediate.

In this presentation, we will focus on mechanistic studies used to determine why the new reaction intermediate is more active than tetrahydrofurfuryl alcohol and why base metals can be utilized for this reaction system. Experiments were performed with nuclear magnetic resonance (NMR) spectroscopy and in situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) to help identify reaction intermediates.

[1] Lux Research, Bio-based Materials and Chemicals Intelligence Service

[2] MarketandMarkets Report on 1,6-Hexanediol

[3] Chia, M. et al. Journal of the American Chemical Society. 2011, 32, 12675-89.

[4] Koso, S. et al. Chemical Communications. 2009, 15, 2035-2037.