Simultaneous saccharification of hemicellulose and cellulose of corncob in a one-pot system using catalysis of carbon based solid acid from lignosulfonate

The drive towards sustainable chemistry has inspired the development of active solid acids as catalysts and ionic liquids as solvents for an efficient release of sugars from lignocellulosic biomass for future biorefinery practices. Carbon-based solid acid (SI–C–S–H2O2) prepared from sodium lignosulfonate, a waste of the paper industry, was used with water or ionic liquid to hydrolyze corncob in this study. The effects of various reaction parameters were investigated in different solvent systems. The highest xylose yield of 83.4% and hemicellulose removal rate of 90.6% were obtained in an aqueous system at 130 °C for 14 h. After the pretreatment, cellulase was used for the hydrolysis of residue and the enzymatic digestibility of 92.6% was obtained. Following these two hydrolysis steps in the aqueous systems, the highest yield of total reducing sugar (TRS) was obtained at 88.1%. Further, one-step depolymerization and saccharification of corncob hemicellulose and cellulose to reducing sugars in an IL-water system catalyzed by SI–C–S–H2O2 was conducted at 130 °C for 10 h, with a high TRS yield of 75.1% obtained directly. After recycling five times, the solid acid catalyst still showed a high catalytic activity for sugar yield in different systems, providing a green and effective method for lignocellulose degradation

Efficient Fractionation of Green Bamboo Using an Integrated Hydrothermal–Deep Eutectic Solvent Pretreatment for Its Valorization

Adopting an integrated strategy to realize efficient fractionation of lignocellulose into well-defined components for its valorization is challenging. Combinatorial pretreatments in this study decomposed hemicellulose of green bamboo during hydrothermal pretreatment (HP), and the hydrothermally pretreated bamboo was subsequently subjected to delignification using deep eutectic solvent (DES) consisting of choline chloride and lactic acid, finally facilitating enzymatic hydrolysis of cellulose residue. Upon hydrothermal treatment at 180 °C for 35 min, hemicellulose removal of 88.6% was achieved with xylo-oligosaccharide yield and purity of 50.9% and 81.6%, respectively. After DES treatment at 140 °C for 2 h, lignin removal was determined to be 79.1%. Notably, the regenerated lignin with high purity of 96.8% displayed superior antioxidant activity, and the decrease in the ratio of syringyl units to guaiacyl units led to a slight decrease in radical scavenging activity of lignin after five recycling runs of DES. Moreover, the two-step treated residue had much higher enzymatic digestibility than that of single HP residue and untreated green bamboo. Results show that synergistic pretreatment is a promising strategy to tackle the recalcitrance of lignocellulose towards high value-added utilization

A Novel SnO₂/ZnFe₂O₄ Magnetic Photocatalyst with Excellent Photocatalytic Performance in Rhodamine B Removal

In this study, we prepared the SnO2/ZnFe2O4 (SZ) composite magnetic photocatalyst via a two-step hydrothermal method. Structural and performance analyses revealed that SZ-5 with a ZnFe2O4 mass ratio of 5% (SZ-5) exhibited optimal photocatalytic activity, achieving a 72.6% degradation rate of Rhodamine B (RhB) solution within 120 min. SZ-5 consisted of irregular nano blocks of SnO2 combined with spherical nanoparticles of ZnFe2O4, with a saturated magnetization intensity of 1.27 emu/g. Moreover, the specific surface area of SnO2 loaded with ZnFe2O4 increased, resulting in a decreased forbidden bandwidth and expanded light absorption range. The construction of a Z-type heterojunction structure between SnO2 and ZnFe2O4 facilitated the migration of photogenerated charges, reduced the recombination rate of electron-hole pairs, and enhanced electrical conductivity. During the photocatalytic reaction, RhB was degraded by·OH, O2−, and h+, in which O2− played a major role