2nd generation sugars 31P NMR Acacia tortilis Cryptococcus curvatus HSQC Kraft lignin Lipomyces starkeyi Napier grass TGA Technology: general issues acid pretreatment alkali pretreatment bio-based reductant bioeconomy bioethanol biofuel biomass biomass fractionation biomimetic biorefinery catalytic lignin oxidation charcoal coal coke electrical resistivity enzymatic hydrolysis enzyme hydrolysis etherification ferroalloy industry furfural