Innovative combined dry fractionation technologies for rice straw valorization to biofuels

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 17; no. 2; pp. 926 - 936
• Main Authors: Chuetor, Santi, Luque, Rafael, Barron, Cécile, Solhy, Abderrahim, Rouau, Xavier, Barakat, Abdellatif
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 01.01.2015
• Subjects: Electrostatics; Energy consumption; Ethyl alcohol; Fractionation; Fuels; Life Sciences; Lignocellulose; Separation; Straw; LIGNOCELLULOSIC BIOMASS; ALKALINE PRETREATMENT; ENZYMATIC-HYDROLYSIS; RESPONSE-SURFACE METHODOLOGY; ENERGY-CONSUMPTION; WHEAT-STRAW; PRETREATMENT CONDITIONS; BIOGAS PRODUCTION; STRUCTURAL FEATURES; CELLULOSIC ETHANOL
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/c4gc01718h

The separation of lignocellulose into its major components (cellulose, hemicelluloses and lignin) is a key step in lignocellulosic biorefineries. Most pretreatments of lignocellulosic biomass into chemicals or biofuels are currently based on expensive chemical and energy consuming processes, which entail significant resource consumption ( e.g. water) and generate a number of residual streams. In this work, two innovative dry fractionation technologies (physical fractionation: turbo- and electrostatic separation of lignocellulose particles) have been developed for rice straw "RS" fractionation and bioconversion to sugars and biofuels. Turbo-fractionation technology (TF-T) comprises particle separation according to their size and density, whereas electrostatic fractionation technology (EF-T) is based on the separation of particles according to their surface properties (chemical composition and charges). TF-T and EF-T are suitable for producing lignocellulose fractions displaying very different structures, biochemical compositions and reactive surfaces without extensively damaging the raw fibers as well as minimizing waste generation ( E -factor: 0.7-0.75). The produced fractions could be hydrolyzed, being able to produce large quantities of glucose (250-280 g kg −1 RS) after 72 h of hydrolysis and subsequently ethanol (130-150 g kg −1 RS) after fermentation. TF-T and EF-T can therefore improve the economic feasibility by low energy consumption and produce reactive lignocellulose particles with different physicochemical structures in a short time, which can be easily converted to biofuels, minimizing waste (no effluent generation). Development of an innovative lignocellulosic biorefinery: milling combined with electrostatic (EF-T) and turbo (TF-T) fractionation technologies of lignocellulose biomass. EF-T and TF-T appear to be interesting technologies for biofuel production from waste feedstocks ( e.g. rice straw) without any chemical or water inputs and minimizing waste generation.