Investigation of a Lignin-Based Deep Eutectic Solvent Using p-Hydroxybenzoic Acid for Efficient Woody Biomass Conversion

Journal Article · Mon Aug 10 00:00:00 EDT 2020 · ACS Sustainable Chemistry & Engineering

DOI:https://doi.org/10.1021/acssuschemeng.0c03533· OSTI ID:1651275

Wang, Yunxuan ^[1]; Meng, Xianzhi ^[2]; Jeong, Keunhong ^[3]; Li, Shuya ^[4]; Leem, Gyu ^[5]; Kim, Kwang Ho ^[6]; Pu, Yunqiao ^[7]; Ragauskas, Arthur J. ^[8]; Yoo, Chang Geun ^[1]

---

1. State Univ. of New York (SUNY), Syracuse, NY (United States). College of Environmental Science and Forestry, Dept. of Chemical Engineering
2. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering
3. Korea Military Academy, Seoul (South Korea). Dept. of Chemistry
4. State Univ. of New York (SUNY), Syracuse, NY (United States). College of Environmental Science and Forestry, Dept. of Chemistry
5. State Univ. of New York (SUNY), Syracuse, NY (United States). College of Environmental Science and Forestry, Dept. of Chemistry; The Michael M. Szwarc Polymer Research Inst., Syracuse, NY (United States)
6. Korea Inst.of Science and Technology, Seoul (South Korea). Clean Energy Research Center; Univ. of British Columbia, Vancouver, BC (Canada). Dept. of Wood Science
7. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Bioenergy Innovation and Biosciences Division, Joint Inst. for Biological Science
8. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering and Dept. of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Bioenergy Innovation and Biosciences Division, Joint Inst. for Biological Science

Deep eutectic solvents (DESs) are effective solvents for biomass conversion and have been proposed as alternatives to ionic liquids (ILs). In this paper, we first report an effective pretreatment of woody biomass using a novel hardwood lignin-based DES prepared from p-hydroxybenzoic acid (PB) and choline chloride (ChCl), which are used as the hydrogen bond donor and acceptor, respectively. The impacts of the ChCl-PB DES on structural properties and enzymatic hydrolysis of poplar wood were comprehensively evaluated. The performance of ChCl-PB DES was also compared with two other DESs with p-coumaric acid (PCA) and 4-hydroxybenzaldehyde (PHA) as the hydrogen bond donors, which have been successfully applied to herbaceous biomass conversion in previous studies. The results showed that hemicellulose and lignin were effectively fractionated during the proposed ChCl-PB DES pretreatment under a relatively mild temperature. The ChCl-PB DES pretreatment resulted in up to 69% of delignification, and the pretreated poplar residues had over 90% of glucose yield by a 72 h-enzymatic hydrolysis. Transformation of poplar biomass during the DES pretreatment was evaluated by gel permeation chromatography (GPC), two-dimensional heteronuclear single quantum coherence (2D-HSQC), and ³¹P nuclear magnetic resonance (NMR) spectroscopies. The recovered lignin showed relatively high purity, narrow molecular weight distribution (PDI < 1.6), and relatively low molecular weight (~1400 g/mol for M_w). A sustainable process was achieved by recycling DES as well as the utilization of PB, which is a producible aromatic compound from hardwood lignin, for the proposed DES formation in the system. This study indicates that the proposed novel DES with a hardwood lignin-based PB compound is a promising pretreatment solvent to achieve an economically feasible biomass conversion process.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: National Institutes of Health (NIH); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1651275
• Journal Information: ACS Sustainable Chemistry & Engineering, Journal Name: ACS Sustainable Chemistry & Engineering Journal Issue: 33 Vol. 8; ISSN 2168-0485
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
biorefinery
characterization
density functional theory
pretreatment
renewable deep eutectic solvent