Sustainable production of high-yield torch ginger nanocellulose using a one-step H2SO4/H2O2 method

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Conventional H 2 SO 4 hydrolysis for nanocellulose isolation from lignocellulosic biomass typically yields only about 20 % and requires multi-step processing with excessive energy and water consumption. This study introduces an efficient one-step H 2 SO 4 /H 2 O 2 method that integrates delignification, hydrolysis, and sulfonation in a single vessel. Torch ginger stem powder with lignin content of ⁓19 % was treated with 60 wt% H 2 SO 4 and 30 wt% H 2 O 2 at a 15:1 liquid-to-solid ratio and 60 °C for 1.5–5 h. The solid reactant was purified by simple filtration, which significantly reduced water and time consumption. The dispersion process employed ultrasonic treatment with an energy requirement comparable to that of conventional hydrolysis. With this method, a 40 wt% nanocellulose yield was obtained within 1.5 h, double that achieved by conventional methods, with ⁓0.14 % of lignin. The isolated nanocellulose had an initial diameter of 6 nm, a length of 2 μm, and a ζ-potential of −30 mV, ensuring long-term colloidal stability. Longer reaction times refined these dimensions to approximately 4 nm in diameter and less than 500 nm in length while increasing crystallinity to 73 %. This innovative method represents a sustainable and scalable route for producing high-quality nanocellulose efficiently from lignocellulosic biomass.