Second-generation biofuels biomass conversion

Second-generation biofuel technologies make use of a much wider range of biomass feedstock (e.g., forest residues, biomass waste, wood, woodchips, grasses and short rotation crops, etc.) for the production of ethanol biofuels based on the fermentation of lignocellulosic material, while other routes include thermo-chemical processes such as biomass gasification followed by a transformation from gas to liquid (e.g., synthesis) to obtain synthetic fuels similar to diesel. The conversion processes for these routes have been available for decades, but none of them have yet reached a high scale commercial level. 

The second-generation biofuels (or advanced biofuels) are derived from lignocellu-losic biomass, nonfood crop feedstocks, agricultural and forest residues, and industrial wastes. They are mainly produced through the utilization of physical, thermochemical, and biochemical technologies, usually after a pretreatment stage of the biomass feedstock (Liew et al., 2014). The pretreatment step is a very important step to prepare the biomass properties (e.g., size, moisture, density, etc.) in order to facilitate the conversion processes (Agbor et al., 2011). 

Second-generation biofuels are based on nonfood crops (ie, Miscanthus) and biomass residues (from crops and forests), thus providing an alternative that is socially acceptable. However, conversion technologies to produce biohydrogen, Bio-DME, Fischer—Tropsch diesel, etc. are still under development. The overall efficiency and... 

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