Xiaoyun Li,Jiaxin Yang,Rui Xu,Lefu Lu,Fangong Kong,Min Liang,Lijie Jiang,Shuangxi Nie,Chuanling Si
The production of platform chemicals from lignocellulosic biomass is scientifically valuable but technologically challenging. With the aim to establish a green reaction system for the production of furfural from lignocellulosic biomass, in the current work, H-SAPO-34 was investigated for catalysis of the conversion of Eucalyptus sawdust to furfural in γ-valerolactone (GVL). H-SAPO-34 was prepared and characterized by XRD, SEM, FTIR, BET, TGA and ammonia adsorbed FTIR. H-SAPO-34 possesses Brønsted and Lewis acid sites and a large specific surface area. The average pore diameter of H-SAPO-34 was 0.86 nm, which is beneficial for the spread of xylose and furfural and the inhibition of humin production. In this work, a peak furfural yield of 99.28% from Eucalyptus was achieved at 210 °C in 120 min with 30 g/L H-SAPO-34. The Brønsted/Lewis acid bifunctionality and the solvent effect of γ-valerolactone possibly contributed to the high furfural yield from real biomass. The kinetics of the conversion of Eucalyptus sawdust to furfural was also studied, and the activation energy for furfural production was calculated. Additionally, the catalytic activity and stability of the regenerated catalyst were estimated.
The current widespread use of plastics is a significant source of environmental pollution and increases the carbon load in the atmosphere, which has precipitated an urgent drive to replace plastics with biomass-based materials. In this paper, we prepared a lignocellulose-based, high-strength, water-resistant composite based on eucalyptus waste sawdust combined with a polyurethane prepolymer. The preparation process included pretreating sawdust with deep eutectic solvents (DESs) to remove some of the lignin and hemicellulose. A prepolymer preparation involving isocyanate groups using the prepolymerization of polyethylene glycol (PEG) with hexamethylene diisocyanate (HDI) grafted the prepolymers to the hydroxyl of the pretreated wood fibers, which were subsequently blended with acetylated pretreated sawdust to create the composite. The composite contained 67% wood fibers, possessed good tensile strength, and exhibited Young’s moduli of 18 MPa and 484 MPa. It was water-resistant with a contact angle of 92° and had a low water absorption of 32%, and it maintained a wet tensile strength of 5.71 MPa. The composite offers several advantages, including UV protection and thermal stability. This high-performance wood waste composite provides an alternative green production option for producing plastic materials.
The magnetic activated carbon (MAC) from eucalyptus sawdust was prepared by one-step method and utilized to remove amoxicillin (AMX) from wastewater. MAC was characterized by N 2 adsorption-desorption, XRD, FT-IRS, Raman, XPS, FESEM, SEM-EDS, vibrating sample magnetometer (VSM) and the point of zero charges ( pH pzc ). The magnetic parameters of MAC were found Hc of 55.92 O e , M s of 21.68 emu g 1 and M r of 0.63 emu g 1 , which resulted from existence of α-Fe and γ-Fe 2 O 3 . MAC existed micropores and mesopores, the specific surface area ( S BET ) and average pore width were 1263.7 m 2 g 1 and 2.07 nm, respectively. Batch adsorption experiments was designed to investigate AMX adsorption behavior on MAC, the adsorption mechanism was also investigated. The AMX removal efficiency was more than 94.3% when 50 mL 400 mg L 1 AMX aqueous solution (3 of pH ) was adsorbed by 0.055 g MAC for 6 h at 25 °C. The AMX adsorption process was consistent with Langmuir isotherm model and the pseudo-second order kinetic model, with maximum adsorption capacities of 485.4 mg g 1 for AMX, the process was affected by the intraparticle diffusion, membrane diffusion and surface adsorption. The AMX adsorption on MAC was spontaneous nd endothermic. The adsorption of AMX on MAC was based on electrosttic interactions, π–π conjugation interactions, and hydrogen bond interactions. MAC had satisfactory adsorption capacity for AMX and recyclability. This work provides a green and environment-friendly method on antibiotic contamination wastewater treatment and a low-carbon green chemical technology for the high-value utilization of eucalyptus residues.
危险品化学品经营许可证（带存储）