Innovative combined dry fractionation technologies for rice straw valorization to biofuels. Issue 2 (16th October 2014) - Chuetor, Santi
Abstract : 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. Abstract : 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).