Lignin recovered from the hot-water extract of sugar maple (Acer saccharum) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of adhesive reinforced glass fibers is determined and compared to the reinforcement level of commercially available PF resin. The adhesive blend prepared at pH = 0.65 with no added furfural exhibits the highest tensile properties and meets 90% of the PF tensile strength.

While there may be many reasons why very interesting science ideas never reach commercial practice, one of the more prevalent is that the reaction or process, which is scientifically possible, cannot be made efficient enough to achieve economic viability. One pathway to economic viability for many business sectors is the multi-product portfolio. Research, development, and deployment of viable biorefinery technology must meld sound science with engineering and business economics. It is virtually axiomatic that increased value can be generated by isolating relatively pure substances from heterogeneous raw materials. Woody biomass is a heterogeneous raw material consisting of the major structural components, cellulose, lignin, and hemicelluloses, as well as minor components, such as extractives and ash. Cellulose is a linear homopolymer of D-glucopyrano-units with β-D(1®4) connections and is the wood component most resistant to chemical and biological degradation. Lignin is a macromolecule of phenylpropanoid units, second to cellulose in bio-resistance, and is the key component that is sought for removal from woody biomass in chemical pulping. Hemicelluloses are a collection of heteropolysaccharides, comprised mainly of 5- and 6-carbon sugars. Extractives, some of which have high commercial value, are a collection of low molecular weight organic and inorganic woody materials that can be removed, to some extent, under mild conditions. Applied Biorefinery Sciences, LLC (a private, New York, USA based company) is commercializing a value-optimization pathway (the ABS Process™) for generating a multi-product portfolio by isolating and recovering homogeneous substances from each of the above mentioned major and minor woody biomass components. The ABS Process™ incorporates the patent pending, core biorefinery technology, “hot water extraction”, as developed at the State University of New York College of Environmental Science and Forestry (SUNY-ESF). Hot water extraction in the absence of mineral acids and bases is preferred because of its ability to generate multiple high value output products without chemical input, recovery, or disposal costs. Instead of added chemicals in the cooking phase, the ABS Process™ relies upon an autocatalytic reaction in which acetyl groups, bound through an ester linkage to hemicellulose chains, are hydrolyzed at high temperature in water. The resulting acidic conditions (final pH ~3.5) and temperatures of 160–170 °C permit further solubilization and diffusion of oligomeric 5- and 6-carbon sugars, acetic acid, aromatic substances, monomeric sugars, and other trace compounds into the extract solution. These conditions also avoid extensive degradation of monosaccharides, enabling membrane fractionation and other chemical separation techniques to be used in the following separations. A range of separation techniques are applied on the extract solution to isolate and purify fermentable sugars, acetic acid, lignin, furfural, formic acid, other hemicellulose related compounds, lignin, lignin degradation products, and phenolic extractives for commercial sale. The extracted lignocellulosic biomass, with reduced hemicellulose content and is thus less heterogeneous, carries the value-added advantages of: (1) enhanced product characteristics, and (2) reduced energy and chemical manufacturing costs. Thus, by fractionating woody biomass into more homogeneous substances, the ABS Process™ holds potential as an economically viable pathway for capturing sustainable, renewable value not currently realized from lignocellulosic biomass.

Cellulosic ethanol is a sustainable alternative to petroleum as a transportation fuel, which could be made biologically from agricultural and forestry residues, municipal waste, or herbaceous and woody crops. Instead of putting efforts on steps overcoming the natural resistance of plants to biological breakdown, our study proposes a unique pathway to improve the outcome of the process by co-producing high-value nanofibrillated cellulose (NFC), offering a new economic leverage for cellulosic ethanol to compete with fossil fuels in the near future. In this study, glucose has been produced by commercial enzymes while the residual solids are converted into NFC via sonification. Here, we report the morphology of fibers changed through the process and yield of glucose in the enzymatic hydrolysis step.

Miscanthus (Miscanthus sp. Family: Poaceae) was hot-water extracted (two h, at 160 °C) at three scales: laboratory (Parr reactor, 300 cm³), intermediate (M/K digester, 4000 cm³), and pilot (65 ft³-digester, 1.841 × 10⁶ cm³). Hot-water extracted miscanthus, hydrolyzate, and lignin recovered from hydrolyzate were characterized and evaluated for potential uses aiming at complete utilization of miscanthus. Effects of scale-up on digester yield, removal of hemicelluloses, deashing, delignification degree, lignin recovery and purity, and cellulose retention were studied. The scale-dependent results demonstrated that before implementation, hot-water extraction (HWE) should be evaluated on a scale larger than a laboratory scale. The production of energy-enriched fuel pellets from hot-water extracted miscanthus, especially in combination with recovered lignin is recommended, as energy of combustion increased gradually from native to hot-water extracted miscanthus to recovered lignin. The native and pilot-scale hot-water extracted miscanthus samples were also subjected to enzymatic hydrolysis using a cellulase-hemicellulase cocktail, to produce fermentable sugars. Hot-water extracted biomass released higher amount of glucose and xylose verifying benefits of HWE as an effective pretreatment for xylan-rich lignocellulosics. The recovered lignin was used to prepare a formaldehyde-free alternative to phenol-formaldehyde resins and as an antioxidant. Promising results were obtained for these lignin valorization pathways.