Selective hydrolysis of traditional Chinese medicine residue into reducing sugars catalysed by sulfonated carbon catalyst and application of hydrolysate.

[Display omitted] • Successful saccharification of CMR using sulfonated biochar derived from pomelo peel. • Elucidation of the fundamental characteristics of sulfonated biochar derived from pomelo peel. • Elucidation of the process variations during the hydrolysis of CMR along with the influence of key reaction conditions on the resulting products. • The role played by the hydrolysate of CMR in the cultivation process of Oocystis. sp. was revealed. The conversion of waste into high-value products has long been a focus point of research in green and sustainable chemistry. In this study, a novel value-adding strategy was devised to not only facilitate the resource utilization of biomass waste like Chinese medicine residue (CMR) and pomelo peel but also contribute to the advancement of microalgae cultivation. Sulfonated biochar PP-700-S was synthesized from pomelo peel waste, and its morphology and structural characteristics were analyzed. An effective method for the hydrolysis of CMR using PP-700-S as a catalyst in the aqueous phase was then explored, with a thorough investigation of the process and key influencing factors. Under the reaction conditions of 130 °C, 24 h, 20 mL H 2 O, CMR: PP-700-S = 1: 1, a 51.87 % yield of reducing sugars was directly obtained from the CMR, with PP-700-S exhibiting the selectivity of glucose production. Subsequently, the hydrolysate (HL-CMR) was utilized as a growth medium for microalgae, revealing that the presence of HL-CMR enhanced the nutrient balance in the medium, creating a more conducive environment for microalgae growth. Overall, this study presents a sustainable and efficient pathway for the utilization of lignocellulosic waste, facilitating the conversion of waste into higher-value products and contributing to the development of a green and sustainable science. [ABSTRACT FROM AUTHOR]