Recent Developments in the Delignification and Exploitation of Grass Lignocellulosic Biomass

Abstract

Biofuels could be defined as the fuels of the future, although much work is still required before they will replace fossil fuels. In this review, lignocellulosic biomass based on straw and related crops and wastes is described concerning its lignin contents, structure, and properties, and an overview on the means of current and predictable delignification protocols is presented. The discussion is focused on herbaceous monocot materials and their available pretreatments (physical, chemical, and enzymatic), with special emphasis on fungal ligninolytic enzymes and the most recent findings and developments in their current application, issues, and perspectives.

Mechanochemical Applications of Reactive Extrusion from Organic Synthesis to Catalytic and Active Materials

“…Cellulose, hemicellulose, and lignin are the main essential components of wheat straw and make it a good feedstock for bioethanol recovery. However, the presence of almost 19% lignin means that it is recalcitrant to direct enzymatic hydrolysis and further fermentation to bioethanol [55]. While a range of physical, chemical, and mechanical treatments, biopretreatments, and combined treatments have recently been reported in the literature [56], mechanical treatment is preferable because of its mild and almost solventless conditions and energy savings.…”

Biocatalysis in ionic liquids: state-of-the-union

“…181 This makes them suitable solvents, alone or in mixtures with water, 182 for lignocellulose pretreatment and in the past decade pretreatment with ILs has emerged as a potentially viable method for industrial scale biomass conversion. 183,184,185,186,187 However, these ILs are not biocompatible which presents problems in the subsequent biocatalytic conversion of the lignocellulose to biofuels and platform chemicals.…”

Bio-Delignification of Green Waste (GW) in Co-Digestion with the Organic Fraction of Municipal Solid Waste (OFMSW) to Enhance Biogas Production

“…Therefore, one major objective of biological pretreatment is to minimize the loss of carbohydrates and maximize the lignin removal for AD feedstocks with high digestibility [44]. Until now, bio-delignification has followed two main approaches: treatments with fungal lignolytic enzymes as free mixtures or immobilized [31,32] and submerged or solid-state fermentations with fungal cells [45]. The microbial treatment includes fungi, such as whiterot fungi, brown-rot fungi, and soft-rot fungi, and bacteria.…”

“…Several attempts have been reported for delignification of GW, and herbaceous waste in general, in order to obtain fermentable sugars, fine chemicals, or renewable biofuels using mechanical, chemical, or physical pretreatments [32]. Most of the processes involve harsh conditions, require the use of chemicals, and produce waste and toxic byproducts, making such processes unsuitable from economic and environmental points of view [33].…”