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The design, modeling and simulation of an integrated biorefinery plant assumed to convert different forestry assortments such as sawdust or shavings (sawmill waste) into bioethanol from cellulose and hemicellulose as the main product, and lignin as the most valuable co-product, was carried out. The proposed lignocellulosic ethanol biorefinery plant was simulated with ProSimPlus. The model was based on experimental results and includes an Organosolv pretreatment, enzymatic hydrolysis, fermentation and distillation to obtain bioethanol. The investigated plant size processed 70,088 tons of biomass/year, with a production capacity of 11,650 tons ethanol/year. Ethanol productivity reached 351 L/ton of dry feedstock. Considering water consumption, approximately 4.8 L of water were needed to produce a liter of ethanol. Finally, the energy targeting through conventional pinch analysis lead to 16.4 MW and 16.07 MW of hot and cold utility energy demand for the entire process respectively with the cogeneration of electricity., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The aim of this work was to demonstrate the feasibility of second-generation bioethanol production using for the first time a sawmill mixed feedstock comprising four softwood species, representative of biomass resource in Auvergne-Rhône-Alpes region (France). The feedstock was subjected to a microwave-assisted water/ethanol Organosolv pretreatment. The investigation focused on enzymatic hydrolysis of this pretreated sawmill feedstock (PSF) using Cellic® Ctec2 as the enzyme, followed by fermentation of the resulting sugar solution using Saccharomyces cerevisiae strain. The cellulose-rich PSF with 71% w/w cellulose content presented high saccharification yields (up to 80%), which made it perfect for subsequent fermentation; this yield was predicted vs. time up to 5.2% w/v PSF loading using a mathematical model fitted only on data at 1.5%. Finally, high PSF loading (7.5%) and scaleup were shown to impair the saccharification yield, but alcoholic fermentation could still be carried out up to 80% of the theoretical glucose-to-ethanol conversion yield., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A mixture of sawmill feedstocks comprising four softwood species (fir, spruce, Scots pine, and Douglas fir) was subjected to a microwave-assisted Organosolv pretreatment. The influence of H 2 SO 4 as a catalyst, ethanol-water ratio as the solvent, and temperature on wood fractionation, cellulose yield and purity, lignin recovery, and inhibitor formation were investigated. Minute addition of H 2 SO 4 (0.25% w/w) was found to enhance lignin extraction and hemicellulose hydrolysis, thus providing cellulose yield and purity above 68% ± 2% and 61% ± 3%, respectively. The increase in H 2 SO 4 up to 1% and temperature up to 190 °C, impaired cellulose yields a result of intense hydrolysis, thus degrading cellulose and hemicellulose. Conversely, the increase in ethanol-water ratio enhanced delignification without cellulose degradation. Similarly, inhibitor formation increased with pretreatment severity (H 2 SO 4 content and temperature), but was mitigated by higher ethanol-water ratio. Finally, under best conditions (60:40 ethanol-water, 175 °C, 0.25% H 2 SO 4 ), cellulose yield and purity reached 82% ± 3% and 71% ± 3%, respectively., (Copyright © 2018. Published by Elsevier Ltd.)

Graphical abstract Abstract Wood is the main source of lignin in the world. This generic term "Lignin" describes a large group of aromatic biopolymers, i.e. the second most abundant class of biopolymers on Earth. It accounts for approximately 30% of wood weight while conferring rigidity and antimicrobial properties to wood. Since lignin is combined with cellulose and hemicellulose in biomass, this will constitute a limiting factor in the bioconversion of wood into pulp or second-generation biofuels through the biochemical pathway. These processes generate a huge quantity of lignin as by-products, mainly used as fuels for energy savings. Recently, alternative routes towards lignin's valorization were emphasized (e.g. as bio-based resins, adhesives, or composites), but they strongly depend on lignin's chemical structure, also dependent on fractionation process. Therefore, this review aims to summarize the strong interplay between extraction processes, resource supply, and recent uses of lignin into bio-based materials. [ABSTRACT FROM AUTHOR]