Biomass Conversion and Biorefinery最新文献

Using biomass to synthesize carbon-based materials has garnered significant interest due to its broad range of applications. Additionally, biomass is a sustainable source with the potential to produce various carbon products. However, the development of practical and efficient processes to enable the high-efficiency utilization of biomass is increasingly attracting attention. To maximize this potential, biomass-derived carbon dots (BioCDots) and hydrochar carbons (HCs) were obtained through a single-step hydrothermal carbonization (HTC) process (140–200 °C for 3 h) from Azolla biomass, without any activation. The physicochemical properties, plant photosynthesis, and electrochemical behavior of the synthesized carbon were evaluated. The BioCDots exhibited a small size and emitted a strong blue fluorescent under UV light. A quantum yield of 20.97% was attained at 200 °C for 3 h. Meanwhile, the obtained residual solids (HCs) exhibited micro/mesopore structure with surface area, pore volume, and average pore diameter of 81.20 m²/g, 0.3963 cm³/g, and 17.18 nm, respectively. For agricultural applications, BioCDots demonstrated a dose-dependent effect on seed germination and could enhance photosynthesis activity in tomato plants, increasing chlorophyll and carotenoid content by approximately 14–35% and 17–31%, respectively, under foliar application at concentrations of 50–300 µg/mL. The HCs revealed a noticeable nitrogen-self-doped hydrochar carbon (NHCs) and delivered a specific capacitance of 83.91 Fg⁻¹ at 0.1 Ag⁻¹ and retains 72% at a current density of 5 Ag⁻¹ in 1 M H₂SO₄ aqueous solution. Promising preliminary results exhibit great potential of BioCDots and HCs from Azolla biomass as foliar agents for stimulating agricultural plant growth and provided a novel proper carbon electrode materials selection for energy storage applications.

Graphical Abstract

The present investigation explores the physicochemical properties, colloidal stability, and tribological characteristics of Cu–Zn nanoparticles (NPs) surface-capped with Oleic acid (OA) in Cashew Nut Shell Liquid Cardanol oil. The functionalized Cu–Zn nanolubricants were formulated with different volume fractions of Cu–Zn NPs viz. 0%, 0.05%, 0.1%, 0.25%, and 0.5% in the synthesized Cardanol oil. The physicochemical properties of the base lubricant and Cu–Zn nanolubricants were evaluated as per ASTM standards. The dispersion stability and functionalization of Cu–Zn/OA nanolubricants were investigated through UV Spectroscopy and FTIR spectroscopy respectively. Further, the tribological behaviour of Cu–Zn NPs in different volume fractions with Cardanol oil was evaluated using a Four-ball tribometer as per ASTM D4172 standards. The results exhibited that the kinematic viscosity of nanolubricants at different temperatures enhanced with the rise in the concentration of nanoparticles. The Cu–Zn NPs surface-capped with OA in base oil exhibited superior stability compared to the unmodified Cu–Zn NPs. Meanwhile, improved dispersion stability was observed for nanolubricants with lower concentrations of Cu–Zn NPs than those with higher concentrations. The outcomes of tribological investigation revealed that the inclusion of 0.1%wt. Cu–Zn NPs exhibited the highest reduction in coefficient of friction and wear scar by 17% and 7% respectively. Moreover, the wear rate declined by 25% for the nanolubricants containing 0.1% wt. Cu–Zn NPs. Further, the surface analysis of worn specimens using SEM / EDS, revealed the lubrication mechanisms that contributed to improving the tribological behaviour of nanolubricants compared to the base lubricants.

The breakdown of cellulose, the most prevalent carbon resource on Earth, by cellulase is very important for acquiring soluble sugars. Solid-state fermentation (SSF) stands out as a proficient approach for generating economically valuable compounds, facilitating cost reduction in production. The fermentation factors were optimized to enhance cellulolytic enzyme production. Of the various inexpensive and readily accessible lignocellulosic residues, sorghum straw emerged as the utmost appropriate substrate. The maximal cellulase productivity of 14.12 ± 0.06 U/g DS was obtained after 72 h of fermentation using sorghum straw with 10% v/v moisture content at pH 7, 37 °C, and an inoculum volume of 1.5% v/v. The crude cellulase was purified using various methods. The employment of the aqueous two-phase system (ATPS) utilizing a polyethylene glycol 8000/MnSO₄ combination demonstrated optimal purification, resulting in a 26.02-fold enhancement in activity, a yield of 48.7%, and a partition coefficient of 1.27. The molecular size of cellulase was approximated to be 84 kDa using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for enzyme activity were identified as 7.0 and 50 °C, respectively. The cellulolytic activity exhibited the highest stimulation in the presence of Mn²⁺. Upon enzymatic saccharification of alkali-treated sorghum feedstock, the highest reducing sugar (30.51 ± 0.13 mg/mL) was obtained after an incubation period of 72 h, with a substrate loading of 4% w/v, enzyme concentration 30 U/g DS, pH 5, and the presence of Tween-80 as a surfactant. These findings may pave the way for a cost-effective and competent process within the framework of the biorefinery concept.

Graphical abstract

Biodiesel combustion in industrial furnaces, which functions as an effective alternative for fossil fuel combustion, is an important energy-saving and emission reduction technology. In this research, the effects of optimizing air conditions on combustion and emission characteristics of waste oil-biodiesel in an industrial furnace were studied through numerical simulation and experiment. The results showed that both the maximum temperature in the furnace and the export concentration of nitric oxide (NO) increased initially and then decreased gradually with an increase in the atomization air volume, and the excess air coefficient exhibits the same pattern of influence on the temperature and NO concentration. Increasing the atomization air volume to 30 L/min produced a lifted flame. A high temperature and low export concentration of NO were observed when the excess air coefficient and atomization air volume were 1.1 and 40 L/min, respectively. The export concentration of NO and maximum temperature were increased with a rise in the air preheating temperature and air oxygen content; however, the growth trend gradually slowed down. The export concentration of NO was increased by more than 30 times, while the air oxygen content rose from 21 to 33%. Meanwhile, the export volume of fuel gas was reduced by 34.3%, which enhanced the heat efficiency of the furnace.

Shrimp processing generates a substantial amount of waste, rich in valuable compounds like carotenoproteins. Traditional extraction methods often rely on harsh chemicals and consume significant energy, raising environmental concerns. This study introduces a sustainable alternative by using ecoenzyme (ECOENZYME–ALKP), a commercial alkaline protease from Bacillus subtilis with very high activity (200,000 U/g), to extract carotenoproteins from Pacific white shrimp waste for the first time. The quality of the extracted carotenoproteins was evaluated based on their chemical composition, antioxidant activities (DPPH, ABTS, FRAP), color, microstructure (SEM), and spectroscopic (FTIR) properties. Response surface methodology (RSM) was employed to optimize the hydrolysis conditions, identifying the optimal parameters as 36.58 °C, 2.99 h, pH 7.94, and 158.17 μl/100 g enzyme concentration. These conditions yielded a maximum degree of deproteinization (DDP) of 94.79% and a degree of hydrolysis (DH) of 51.28%. The results were compared to traditional NaOH methods, with the carotenoprotein powder produced by ecoenzyme (CPE) showing superior protein content, higher whiteness index, enhanced antioxidant activities, and stronger beta-sheet intensity compared to the carotenoprotein powder produced by chemical method (CPC). Both CPE and CPC exhibited increased DPPH radical scavenging, ABTS, and FRAP activities as concentrations increased up to 9 mg/ml (p < 0.05). The ecoenzyme proved to be both efficient and eco-friendly in producing high-quality carotenoproteins, making the resulting protein powder a viable option for use as a functional food ingredient for humans or animal feed. Notably, the ecoenzyme required significantly less enzyme (158.97 μl/100 g) compared to previous studies, highlighting its potent hydrolyzing ability.

The present study emphasizes the mechanical characteristics and water uptake behavior of seashell, eggshell, and coconut fillers added with sisal, kenaf, and pineapple leaf fiber-reinforced epoxy composites. The present study compares the difference in mechanical performance between filler-based composites with only fiber-based composites. The weight proportion of fillers and fiber reinforcement collectively were 30% by weight, and epoxy was 70% by weight in all prepared specimens. According to the results of the experimental findings, the inclusion of biofillers with fiber and hybridization of fibers gives a reduction in void content as sisal/epoxy/seashell composite shows a minimum 2.09% void content than other specimens. Hybrid pineapple/sisal/kenaf/epoxy composite absorbs minimum water content during the water immersion test. Kenaf/epoxy/seashell composite exhibits a maximum tensile strength of 72.25 MPa, and kenaf/epoxy/eggshell composite achieved a maximum value of tensile modulus at 30.49 GPa as compared to other developed composite specimens. While flexural strength was maximum for sisal/epoxy/eggshell composite at 257.25 MPa, flexural modulus was maximum for kenaf/epoxy/eggshell composite at 68.4 MPa. Sisal/epoxy/coconut composite achieved a maximum impact strength of 0.9 J as compared to all developed composite specimens. Scan electron microscopy (SEM) reveals the mechanism of fiber/matrix debonding, fiber fracture, and fracture of matrix after mechanical testing.

The present study aimed at investigating the photocatalytic activity of biosynthesized bismuth ferrite (BiFeO₃) nanoparticles as catalysts for the degradation of toxic methylene blue (MB) dye. The BiFeO₃ nanoparticles were synthesized using a simple and low-cost method, mediated by leaf extract of Strychnos nux-vomica plant. Several characterization techniques, including XRD, FTIR, Raman spectroscopy, DLS, Zeta potential, FESEM with EDX, HRTEM, SQUID and UV–vis spectroscopy were employed to investigate the properties of these nanoparticles. The XRD analysis coupled with Rietveld refinement, indicated the purity of the material, showing a rhombohedral phase, which was further validated by Raman analysis. FTIR analysis revealed the presence of various phytochemicals, which perhaps have played a great role in synthesis process of nanoparticles. The estimated optical band gap was nearly 1.98 eV, smaller than the previously reported data. The SQUID measurements indicated weak ferromagnetic nature of these nanoparticles, possibly due to the formation of canted Fe sublattice, influenced by Dzyaloshinskii–Moriya interactions. The FESEM and HRTEM images revealed the irregular shape of nanoparticles with an average size of around 37 nm. The prepared nanoparticles were used as photocatalyst for photodegradation of MB dye under sunlight irradiation. The synthesized nanoparticles demonstrated effective photocatalytic activity, achieving complete degradation of MB dye under sunlight exposure with optimal conditions: pH 2, catalyst dose of 50 mg, and irradiation time of 80 min. The scavenger test indicated the important role of superoxide radicals and hydroxyl radicals in the photodegradation mechanism. Furthermore, the reusability test demonstrated stability even after three cycles without significant loss in its activity. Therefore, these results demonstrate that these biosynthesized BiFeO₃ nanoparticles are promising for the efficient removal of organic pollutants from wastewater.

Dye and pesticide are highly toxic among the category of organic contaminants. Due to the failure of traditional techniques to provide efficient solution for remediation, alternatives like bioremediation are the hotspot of research by scientists. The modified alginate beads developed in this paper has been utilized for the degradation of chlorpyrifos and methylene blue. The alginate beads were primarily formed with the help of extrusion method and were modified with woodchar. Bacillus cereus strain EBCH14 was encapsulated in the beads. The final modified bead underwent SEM analysis and the elemental composition revealed the presence of carbon and phosphorus which indicated the adsorption potential of the beads and the presence of bacterial cell respectively. The SEM images focused on the abundance of endospores inside the pores of the bead. After carrying out parameter optimization, it was ascertained that these beads can degrade up to 230 mg/L of chlorpyrifos and 120 mg/L of dye. The degradation kinetics showed that considerable amount of contaminants were removed within 12 days and the half-life of the contaminants in the experimental flasks were quite low compared to the controls. GCMS proved that simple alkanes, fatty acids, or plant derivatives were present in the final products, and hence, it is assumed that the degraded products are less hazardous than their parent counterparts. The COD of both contaminants reduced by 90% at the end of 12th day. Thus, the developed encapsulated beads are efficient in degrading substantial amounts of both methylene blue and chlorpyrifos.

The objective of this research is to explore the fatigue, creep, flammability, and thermal conductivity performance of a polyester bio-composite developed using cellulose extracted from jackfruit seed husk and pineapple leaf fibre. The fabrication of the composite involves mixing the jackfruit husk cellulose with the matrix and employing the hand layup technique. Both the cellulose and fibre undergo silane treatment to enhance the composite’s strength. The study conducts a comprehensive characterisation of the composite material following ASTM standards. The findings indicate that the composite labelled PC2, with a 2 vol.% filler addition, exhibits the highest fatigue life counts of 25,860, 21,446, and 16,530 for 25%, 50%, and 75% of the ultimate tensile strength (UTS), along with minimal creep strain values of 0.0326, 0.036, 0.039, 0.041, and 0.045 over time intervals of 2000s, 4000 s, 6000 s, 8000 s, and 10,000 s. Additionally, scanning electron microscopy (SEM) images reveal enhanced bonding between reinforcements and the matrix. Despite a slight impact on flame resistance, the addition of cellulose maintains a V-0 flame rating. Furthermore, the composite designation PC3, containing 4 vol. % cellulose, records the highest thermal conductivity at 0.192 W/mK. These time-dependent property improvements suggest that the developed composites could find applications in various industries, including automotive, aviation, defence, household appliances, and the space sector.

The need to mitigate environmental impacts in the power sector has driven research into sustainable bio-liquid insulation alternatives for transformers. This study focuses on developing and rigorously evaluating biodegradable electro-insulating liquids, specifically Karanja oil and Mahua oil, as eco-friendly substitutes for conventional petroleum-based transformer oil. To reduce viscosity, a decane paraffin solvent was added. Comprehensive analyses of the physicochemical properties, AC and impulse breakdown characteristics under various conditions, statistical AC and impulse breakdown voltage, partial discharge behavior, and Weibull distribution survival analysis were conducted. Results show that additive-included Karanja oil and Mahua oil have promising potential as sustainable bio-liquid insulation alternatives. Both oils exhibit good physicochemical characteristics and excellent dielectric breakdown under AC and impulse exposure. Superior performance in survival and hazard in adverse conditions was supported by partial discharge inception voltage and Weibull statistical analysis with Karanja oil and Mahua oil. While some limitations were identified, they can be addressed with appropriate mitigation approaches. This methodical development and analysis underscore the environmental compatibility of these oils without compromising performance metrics. The findings establish Karanja oil and Mahua oil as promising, efficient alternatives for sustainable power transformer insulation, expanding viable options for the power industry.