The production of renewable chemicals and biofuels must be cost- and performance- competitive with petroleum-derived equivalents to be widely accepted by markets and society We propose a biomass conversion strategy that maximizes the conversion of lignocellulosic biomass (up to 80% of the biomass to useful products) into high-value products that can be commercialized, providing the opportunity for successful translation to an economically viable commercial process Our fractionation method preserves the value of all three primary components: (i) cellulose, which is converted into dissolving pulp for fibers and chemicals production; (ii) hemicellulose, which is converted into furfural (a building block chemical); and (iii) lignin, which is converted into carbon products (carbon foam, fibers, or battery anodes), together producing revenues of more than $500 per dry metric ton of biomass Once de-risked, our technology can be extended to produce other renewable chemicals and biofuels

https://advances.sciencemag.org/content/advances/3/5/e1603301.full.pdf

Increasing the revenue from lignocellulosic biomass: Maximizing feedstock utilization

We report a process for converting fructose, at a high concentration (15 weight %), to 2,5-furandicarboxylic acid (FDCA), a monomer used in the production of polyethylene furanoate, a renewable plastic. In our process, fructose is dehydrated to hydroxymethylfurfural (HMF) at high yields (70%) using a γ-valerolactone (GVL)/H2O solvent system. HMF is subsequently oxidized to FDCA over a Pt/C catalyst with 93% yield. The advantage of our system is the higher solubility of FDCA in GVL/H2O, which allows oxidation at high concentrations using a heterogeneous catalyst that eliminates the need for a homogeneous base. In addition, FDCA can be separated from the GVL/H2O solvent system by crystallization to obtain >99% pure FDCA. Our process eliminates the use of corrosive acids, because FDCA is an effective catalyst for fructose dehydration, leading to improved economic and environmental impact of the process. Our techno-economic model indicates that the overall process is economically competitive with current terephthalic acid processes.

Toward biomass-derived renewable plastics: Production of 2,5-furandicarboxylic acid from fructose

The implementation of biorefineries based on lignocellulosic materials as an alternative to fossil-based refineries calls for efficient methods for fractionation and recovery of the products. The focus for the biorefinery concept for utilisation of biomass has shifted, from design of more or less energy-driven biorefineries, to much more versatile facilities where chemicals and energy carriers can be produced. The sugar-based biorefinery platform requires pretreatment of lignocellulosic materials, which can be very recalcitrant, to improve further processing through enzymatic hydrolysis, and for other downstream unit operations. This review summarises the development in the field of pretreatment (and to some extent, of fractionation) of various lignocellulosic materials. The number of publications indicates that biomass pretreatment plays a very important role for the biorefinery concept to be realised in full scale. The traditional pretreatment methods, for example, steam pretreatment (explosion), organosolv and hydrothermal treatment are covered in the review. In addition, the rapidly increasing interest for chemical treatment employing ionic liquids and deep-eutectic solvents are discussed and reviewed. It can be concluded that the huge variation of lignocellulosic materials makes it difficult to find a general process design for a biorefinery. Therefore, it is difficult to define “the best pretreatment” method. In the end, this depends on the proposed application, and any recommendation of a suitable pretreatment method must be based on a thorough techno-economic evaluation.

/pdf/pretreatment-for-biorefineries-a-review-of-common-methods-2cnajwqkqo.pdf

Pretreatment for biorefineries: a review of common methods for efficient utilisation of lignocellulosic materials

The production of furfural directly from hemicellulose in lignocellulosic biomass : A review

Green synthesis of gamma-valerolactone (GVL) through hydrogenation of biomass-derived levulinic acid using non-noble metal catalysts : A critical review

https://pubs.rsc.org/en/content/articlepdf/2016/gc/c6gc01692h

Wood biorefinery based on γ-valerolactone/water fractionation

The solubility of lignin in a mixture of γ-valerolactone (GVL) and water at different weight ratios was measured using the Hildebrand solubility parameters. Based on the molecular structure of lignin, its solubility parameter (δ-value) was calculated as 25.5 MPa1/2 . The δ-value for aqueous GVL solvent increased from 23.1 MPa1/2 for pure GVL to 45.6 MPa1/2 for pure water. Therefore, the lignin solubility was predicted to increase with increasing GVL concentration in the aqueous mixture up to approximately 92-96 wt % of GVL. A ternary diagram describing the phase behavior of water-GVL-lignin mixtures at room temperature was constructed based on the experimental results. The three-component system exhibited a complex behavior with a liquid-liquid and solid-liquid-liquid phase split. The efficiency of the selected fractionation trials in a previous work was validated using the ternary solubility diagram. A promising recovery pathway and lignin isolation method were deduced from the results of this work.

/pdf/solubility-of-organosolv-lignin-in-g-valerolactone-water-nii55tlc76.pdf

Solubility of Organosolv Lignin in γ-Valerolactone/Water Binary Mixtures

The influence of lignin content on nanocellulosic fibril morphology, charge, colloidal stability and immobilization has been systematically investigated employing a series of nanofibrillated cellulose (NFC) with varying residual lignin content and compared to those of NFC made from fully bleached pulp. The lignin-containing pulps were obtained from the fractionation of Eucalyptus globulus wood chips in gamma-valerolactone (GVL)/water under the same conditions, they differ by the intensity of washing for lignin removal. The reference pulp originated from another cook of eucalyptus wood chips, and was fully bleached with a short Elemental-Chlorine-Free (ECF) sequence. All the pulps have a comparable hemicellulose-to-cellulose ratio and CED viscosity. NFC suspensions of 1 wt% concentration were mechanically produced from fluidization. The results indicated that the fibrils morphology, thickness and corresponding flocculation within NFC suspensions was highly influenced by the presence of lignin unevenly distributed on the fibril surface and within the suspension as particles. The presence of lignin in NFC suspension had a large impact on the rheology and dewatering of the NFC. Samples with high lignin content had distinguishable viscoelastic properties due to the greater flocculation of thicker fibrils and lower gel-like characteristics, with better dewatering properties.

Effect of lignin on the morphology and rheological properties of nanofibrillated cellulose produced from γ-valerolactone/water fractionation process

Thermodynamic measurements were made for the binary mixture of water + γ-valerolactone (GVL) and for pure GVL to facilitate the development of the technology of lignin removal from lignocellulosic biomass (Fang, W.; Sixta, H. Advanced Biorefinery based on the Fractionation of Biomass in γ - Valerolactone and Water. ChemSusChem 2015, 8, 73−76). The density and vapor pressure of pure GVL as a function of temperature were measured and correlated for a wide range of the temperatures and pressures. Isothermal vapor–liquid equilibrium (VLE) data of the binary mixture of water + GVL were measured at 350.2 K with a static total pressure apparatus. Absence of an azeotrope was confirmed by circulation still measurements with diluted GVL solutions. Excess molar enthalpy (hE) of the mixture for the whole range of mole fractions including infinite dilution was measured using a SETARAM C80 calorimeter equipped with a flow mixing cell at 322.6 and 303.2 K. The VLE and hE data were used for the optimization of UNIQUAC an...

Vapor–Liquid Equilibria, Excess Enthalpy, and Density of Aqueous γ-Valerolactone Solutions.

We introduce the optimization of the pulping conditions and propose different chemical recovery options for a proven biorefinery concept based on γ-valerolactone (GVL)/water fractionation. The pulping process has been optimized whereby the liquor-to-wood (L:W) ratio could be reduced to 3 L/kg without compromising the pulp properties as raw material for textile fibers production. The recovery of the pulping solvent was performed through combinations of lignin precipitation by water addition, distillation at reduced pressure, and liquid CO2 extraction. With a two-step lignin precipitation coupled with vacuum distillation, more than 90% of lignin and GVL could be recovered from the spent liquor. However, a significant part of GVL remained unrecoverable in the residue, which was a highly viscous liquid with complicated phase behavior. The recovery by lignin precipitation combined with liquid CO2 extraction could recover more than 85% GVL and 90% lignin without forming any problematic residue as in the distillation process. The remaining GVL remained in the raffinate containing a low amount of lignin and other compounds, which can be further processed to isolate the GVL and improve the recovery rate.

/pdf/chemical-recovery-of-g-valerolactone-water-biorefinery-4hsawkjk9i.pdf

Huy Quang Lê

Papers

Wood biorefinery based on γ-valerolactone/water fractionation

Solubility of Organosolv Lignin in γ-Valerolactone/Water Binary Mixtures

Effect of lignin on the morphology and rheological properties of nanofibrillated cellulose produced from γ-valerolactone/water fractionation process

Vapor–Liquid Equilibria, Excess Enthalpy, and Density of Aqueous γ-Valerolactone Solutions.

Chemical Recovery of γ-Valerolactone/Water Biorefinery.