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This content will become publicly available on March 6, 2019

Title: Temperature-dependent phase behaviour of tetrahydrofuran–water alters solubilization of xylan to improve co-production of furfurals from lignocellulosic biomass

Xylose, Xylan, Hemicellulose, CELF, THF, Co-solvent, Pretreatment, Biomass ABSTRACT: Xylan is an important polysaccharide found in the hemicellulose fraction of lignocellulosic biomass that can be hydrolysed to xylose and further dehydrated to the furfural, an important renewable platform fuel precursor. Here, pairing molecular simulation and experimental evidences, we reveal how the unique temperature-dependent phase behaviour of water-tetrahydrofuran (THF) co-solvent can delay xylan solubilization to synergistically improve catalytic co-processing of biomass to furfural and 5-HMF. Our results indicate, based on polymer correlations between polymer conformational behaviour and solvent quality, that both co-solvent and aqueous environments serve as ‘good’ solvents for xylan. Interestingly, the simulations also revealed that unlike other cell-wall components (i.e., lignin and cellulose), the make-up of the solvation shell of xylan in THF-water is dependent on the temperature-phase behaviour. At temperatures between 333K and 418K, THF and water become immiscible, and THF is evacuated from the solvation shell of xylan, while above and below this temperature range, THF and water are both present in the polysaccharide’s solvation shell. This suggested that the solubilization of xylan in THF-water may be similar to aqueous-only solutions at temperatures between 333K and 418K and different outside this range. Experimental reactions on beachwood xylanmore » corroborate this hypothesis by demonstrating 2-fold reduction of xylan solubilization in THF-water within a miscible temperature regime (445K) and unchanged solubilization within an immiscible regime (400K). Translating this phase-dependent behaviour to processing of maple wood chips, we demonstrate how the weaker xylan solvation in THF-water under miscible conditions can delay furfural production from xylose, allowing 5-HMF production from cellulose to “catch-up” such that their high yield production from biomass can be synergized in a single pot reaction.« less
Authors:
ORCiD logo [1] ; ORCiD logo [2] ;  [3] ;  [1] ;  [1]
  1. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of California, Riverside, CA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; FWP ERKP752; EE0007006; AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Green Chemistry
Additional Journal Information:
Journal Volume: 20; Journal Issue: 7; Journal ID: ISSN 1463-9262
Publisher:
Royal Society of Chemistry
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1435286
Alternate Identifier(s):
OSTI ID: 1434087