Organic solvent pretreatment of lignocellulosic biomass for biofuels and biochemicals: A review

Miscanthus represents a key candidate energy crop for use in biomass-to-liquid fuel-conversion processes and biorefineries to produce a range of liquid fuels and chemicals; it has recently attracted considerable attention. Its yield, elemental composition, carbohydrate and lignin content and composition are of high importance to be reviewed for future biofuel production and development. Starting from Miscanthus, various pre-treatment technologies have recently been developed in the literature to break down the lignin structure, disrupt the crystalline structure of cellulose, and enhance its enzyme digestibility. These technologies included chemical, physicochemical, and biological pre-treatments. Due to its significantly lower concentrations of moisture and ash, Miscanthus also represents a key candidate crop for use in biomass-to-liquid conversion processes to produce a range of liquid fuels and chemicals by thermochemical conversion. The goal of this paper is to review the current status of the technology for biofuel production from this crop within a biorefinery context.

Miscanthus: a fast-growing crop for biofuels and chemicals production

The molecular weight of lignin is a fundamental property that infl uences the recalcitrance of biomass and the valorization of lignin. The determination of the molecular weight of lignin in native biomass is dependent on the bioresources used and the isolation and purifi cation procedures employed. The three most commonly employed isolation methods are milled wood lignin (MWL), cel- lulolytic enzyme lignin (CEL), and enzymatic mild acidolysis lignin (EMAL). Common characterization techniques for determining the molecular weight of lignin will be addressed, with an emphasis on gel permeation chromatography (GPC). This review also examines the mechanisms behind several biological, physical, and chemical pre-treatments and their impact on the molecular weight of lignin. The number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (D) all vary in magnitude depending on the biomass source, pre-treatment conditions, and isola- tion method. Additionally, there is a growing body of literature that supports changes in the molecular weight of lignin in response to genetic modifi cations in the lignin biosynthetic pathways. This review summarizes different procedures for obtaining the molecular weight of lignin that have been used in recent years and highlight future opportunities for applications of lignin. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd

Characterization and analysis of the molecular weight of lignin for biorefining studies

Organosolv pretreatment of plant biomass for enhanced enzymatic saccharification

Physico-chemical properties and thermal stability of microcrystalline cellulose isolated from Alfa fibres.

Green microalgae, and Chlorophyta in particular, are considered as a renewable source of valuable chemicals for biofuel, nutraceutical or pharmaceutical industries, among others. Microalgae store most of their valuable components inside the cell behind a thick and resistant cell wall. Energy- or solvent-consuming steps are therefore needed to overcome this physical barrier and efficiently extract the desired compounds. Moreover, in a biorefinery context, the wall itself represents a valuable co-product. Although accurate knowledge of microalgal cell walls would be useful for product and process development and overall cost reduction, walls are still poorly understood. High discrepancies in structure and/or composition are regularly described within families, genera or species due to phenotypic plasticity, life cycle stage or erroneous taxonomical classification. Massive progress has been made in this latter research area, which gives, when compiled with the studies focusing on cell walls, a better understanding of micro-algal cell walls. This review focuses on the detailed cell wall structure and composition of Chlorophyta with a particular focus on, but not limited to, industrial micro-algae.

A new insight into cell walls of Chlorophyta

https://hal.univ-lorraine.fr/hal-03140955/document

Combination of enzymatic hydrolysis and ethanol organosolv pretreatments: Effect on lignin structures, delignification yields and cellulose-to-glucose conversion

An enzyme method of extracting oils, proteins and fermentable sugars from vegetable matter in an aqueous medium, including the following steps: a) adding water to the vegetable matter having a suitable particle size; b) adding an enzyme mixture containing at least one cellulase, at least one hemicellulase and at least one pectinase, the ratio between the pectinase activity and the cellulase activity being at least 0.14, the ratio between the pectinase activity and the hemicellulase activity being at least 7.10-3, and the pectinase activity being less than 120 μmol/min/ml; c) incubating the vegetable matter and the enzyme mixture under agitation; d) separation of the reaction medium in order to obtain free oil, an aqueous phase containing proteins and fermentable sugars, and a solid phase; e) optionally separating an emulsion of the free oil or the aqueous phase, and recycling the emulsion in the reaction medium; and f) separating the proteins and fermentable sugars from the aqueous phase.

Enzyme method of extracting oils and proteins from vegetable matter in an aqueous medium

Aqueous enzymatic extraction is employed for fractionation of plant raw material and for extraction of molecules of interest in a safe manner. For many years, the improvement of industrial enzymes lead to new potentialities and new products and implies today an entire rethinking of green extraction and its economic prospects.

Enzymatic Aqueous Extraction (EAE)

Procede d'extraction enzymatique en milieu aqueux d'huiles, de proteines et de sucres fermentescibles a partir de matiere vegetale, comprenant les etapes suivantes : a) addition d'eau a de la matiere vegetale, b) addition d'un melange enzymatique contenant au moins une cellulase, au moins une hemicellulase et au moins une pectinase, le rapport entre l'activite de la pectinase et l'activite de la cellulase etant d'au moins 0.14, le rapport entre l'activite de la pectinase et l'activite de l'hemicellulase etant d'au moins 7.10 -3 , l'activite de la pectinase etant inferieure a 120 μmol/min/ml, c) incubation sous agitation de la matiere vegetale et du melange enzymatique, d) separation du milieu reactionnel pour obtenir de l'huile libre, une phase aqueuse contenant des proteines et des sucres fermentescibles, et une phase solide, e) eventuellement separation d'une emulsion de l'huile libre ou de la phase aqueuse, et recyclage de l'emulsion dans le milieu reactionnel, f) separation des proteines et des sucres fermentescibles de la phase aqueuse.

Guillaume Ricochon

Papers

A new insight into cell walls of Chlorophyta

Combination of enzymatic hydrolysis and ethanol organosolv pretreatments: Effect on lignin structures, delignification yields and cellulose-to-glucose conversion

Enzyme method of extracting oils and proteins from vegetable matter in an aqueous medium

Enzymatic Aqueous Extraction (EAE)

Procede d'extraction enzymatique en milieu aqueux d'huiles et de protéines a partir de matière végétale