Short-life bamboo lignocellulose is superior-convertible for advanced bioethanol and nanomaterials to decline CO2 emission and environmental impacts.

Abstract

Efficient utilization of bamboo lignocellulose remains challenging because its recalcitrance limits biomass conversion and utilization. Here, we demonstrate a cascading biorefinery strategy of one-year-old (Y1) bamboo by maximizing bioethanol production and converting all enzymatic residues into high-value nanomaterials. While the global lignocellulose harvest of Y1 bamboo was estimated for boosting sugars and bioethanol production, the enzyme-undigested residues were recycled to generate smaller cellulose nanofibrils and shorter cellulose nanocrystals by 21% and 50%, compared to its raw material and other 3- and 5-year-olds bamboo samples. The ultrafine lignin nanoparticles of Y1 undigested-residues with 92%-96% reduced diameters were subsequently obtained to generate the graphitic nanocarbon with the second largest specific-surface-area at 2865 m2 g-1 among the most biomass-based carbons as previously reported. The nanocarbon was detected with much higher specific electro-capacitance at 261 F g-1 and consistently higher CO2 adsorption capacity at 4.3 mmol g-1. Notably, the 75-year life cycle assessments anticipate total carbon captures from advanced bioethanol and nanomaterials productivity of the Y1 bamboo, which may decline global warming and environmental impacts by replacing petrol-fuels and low-value bioproducts. This study thus demonstrates that short-life bamboo offers multiple recycling advantages for efficient biofuel conversion and effective bioproduct invention associated with the integrative reduction of total CO2 emissions by cascading lignocellulose utilization and zero-biomass liberation.