Biomass Conversion and Biorefinery最新文献

This research investigates epoxy resin composites reinforced with bagasse microfiber and custard apple husk biocarbon, with a focus on their mechanical properties, thermal stability, flammability, and water absorption. Epoxy resin, combined with 40 vol.% bagasse microfiber and varying levels of biocarbon content, forms composites designed to enhance strength, durability, and resistance for demanding applications. The custard apple husk biocarbon, derived through a multi-stage pyrolysis process, contributes to the composite’s improved thermal stability and reduced water absorption, making it suitable for industries such as shipping, automotive, aerospace, and infrastructure. Specimen EB2, which incorporates 3 vol.% biocarbon, exhibits exceptional mechanical properties, including a tensile strength of 145 MPa and a flexural strength of 160 MPa. These improvements are attributed to the ideal dispersion of biocarbon, which enhances load-bearing capacity and impact resistance. On the other hand, specimen EB3, with 5 vol.% biocarbon, demonstrates superior flame resistance, with the lowest flame propagation speed observed (5.44 mm/min), along with enhanced thermal stability (degradation temperature of 384 °C) and minimal water absorption (0.04%). The higher biocarbon content contributes to dense char formation, serving as a thermal and flame barrier, thus reducing the composite’s flammability. The stir casting fabrication method used in this study ensures an even distribution of fibers and fillers, leading to composites that outperform conventional materials in terms of strength and thermal endurance while maintaining a lightweight profile.

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This study explores the use of Moringa oleifera plant parts—seeds (MoS), husks (MoK), and leaves (MoL)—as low-cost bioadsorbents for the removal of methylene blue (MB) from aqueous solutions. The adsorbents were incorporated into gelatin-based hydrogel beads and evaluated under varying conditions, including pH, dosage, initial MB concentration, contact time, and temperature. The adsorption process followed pseudo-second-order kinetics and fitted best with the Sips isotherm model. Maximum adsorption capacities were 140 mg g⁻¹ for MoS/Gel, 90 mg g⁻¹ for MoL/Gel, and 85 mg g⁻¹ for MoK/Gel at pH 8.0 and 298 K, achieving removal efficiencies between 75-90% within 10 min. FTIR-ATR analysis confirmed the involvement of functional groups such as –COOH, –OH, –NH₂, and C = O in the adsorption process. The results highlight that Moringa oleifera, particularly its seeds, as an effective and sustainable option for dye removal in water treatment.

Biochar-derived dissolved organic matter (BDOM) plays a diverse role in the soil ecosystem, including stimulation of microbial activities and the fate of nutrients and toxic metals (TMs) in soil. This study employed optical analysis techniques to characterize the fluorescent properties of BDOM released from sheep bone-biochar (SB) and compared it with biochars from rice husk (RB; plant-based) and rabbit manure (MB; manure-based) pyrolyzed at 400 °C (low pyrolysis temperature, LPT) and 700 °C (high pyrolysis temperature, HPT). The results showed that pyrolytic temperature and feedstock type had a strong influence on BDOM content and composition. Overall, LPT generates large BDOM contents compared with the biochar prepared at HPT. Rice husk (RB; 1438.5 mg kg⁻¹) and rabbit manure (MB, 729.7 mg kg⁻¹) biochars produced higher BDOM contents compared to sheep bone biochar (SB; 495.2 mg kg⁻¹) pyrolyzed at 400 °C. Additionally, bone-derived biochar revealed greater fluorescence (3.42), freshness (1.57), and biological (1.98) indices versus plant- and manure-derived biochar. The specific ultraviolet spectroscopy (SUVA254 and SUVA260) indicated the highest aromaticity and hydrophobicity for SB400 (5.92 and 5.44 L mg⁻¹ m⁻¹), which remained high even at HPT (SB700; 4.91 and 4.24 L mg ¹ m ¹). Parallel Factor Analysis component analysis revealed higher humic acid-like (84%), fulvic acid-like (74%), microbial by-products (27%), and aromatic protein-like (53%) components with bone-derived BDOM compared with plant and manure. Higher fluorescence intensity revealed the presence of higher concentrations of degradable, fresh, bioavailable, and humic recalcitrant substances in BDOM. This represents the first comparison report on the fluorescent properties of BDOM derived from bone-, plant-, and manure-based biochars. The optical analysis techniques provided valuable insights into BDOM characteristics.

The pyrolytic degradation of pomegranate peels with and without a catalyst at different operating temperatures is described. Initially, the pomegranate peels were subjected to elemental analysis (CHNS) and thermogravimetric (TG) Analysis to evaluate the elemental composition and thermal degradation behavior, respectively. Silver nanoparticles employed for the catalytic pyrolysis process were synthesized in the laboratory by adopting a wet chemical reduction technique with hydrazine hydrate as a reducing agent. The surface morphology and porosity of the synthesized nanoparticles were recorded by employing FESEM-EDX along with elemental mapping and BET analysis. About 30 g of dried pomegranate peels was admixed with silver nanoparticles (0.1 g and 0.2 g) individually and subjected to pyrolysis at different temperatures ranging 400–550 °C. The products obtained during both the thermal and catalytic pyrolysis were collected and stored separately for further studies. Also, the efficacy of biochar retained during the pyrolysis as an electrode material was evaluated. The specific capacitance of Ag nanoparticles (0.1 g) –embedded biochar was higher (276.94 Fg⁻¹) at a scan rate of 10 mV/s than the thermal pyrolysis biochar, which may be due to the existence of a porous structure of the biochar and better electrical conductivity.

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Mexican giant hyssop (Agastache mexicana subsp. xolocotziana) is an endemic Mexican plant traditionally used as a sleeping inducer. The aim of this study was to evaluate the effect of selected processing variables on the extraction of essential oil (EO) using surfactant-assisted hydrodistillation (SAH). Response surface methodology (RSM), coupled with a face-centered central composite design, was used to optimize the oil extraction process. The factors studied included the concentration of Tween 20 (0.001 – 0.007 g/mL), the solid–liquid ratio (15.8 – 45.8 g/L), and the extraction time (0.5 – 3.0 h). The experimental data obtained were fitted to a second-order polynomial model. The results showed that the concentration of Tween 20 and the solid–liquid ratio had a significant effect (P < 0.005) on the essential oil yield. Additionally, all three factors studied significantly affected (P < 0.005) the antioxidant activity, as measured by the DPPH radical scavenging activity. The optimal conditions for extracting oil from Agastache mexicana subsp. xolocotziana (AMX) were determined to be 0.001 g/mL of Tween 20, a solid–liquid ratio of 45.8 g/L, and an extraction time of 2.86 h. The GC-MS analysis of the essential oil showed that nerol was the main component, whose presence was confirmed by infrared spectroscopy. The antibacterial activity of EO was evaluated by determining the inhibition diameter, with results indicating that the antibacterial activity was higher when using hydrodistillation compared to SAH. The study concluded that the AMX essential oil showed significant DPPH radical scavenging activity and antibacterial activities. Additionally, surfactant-assisted hydrodistillation (SAH) was identified as a sustainable method for essential oil extraction, due to its reduced environmental impact.

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The growing global energy demand and the limitations of fossil fuels which are polluting, costly, geographically restricted, and non-renewable, have prompted the exploration of sustainable alternatives. Among these, bio-photovoltaic systems (BPVs) represent a promising green technology with significant potential for renewable energy production. In this study, a plant-based biofuel cell (PBFC) was designed to generate electricity by exploiting photosynthesis as a driving force for microbial electrochemical activity in the rhizosphere. The experimental setup consisted of a bioanode and a biocathode inserted into a soil-filled container hosting Crassula ovata. The bioanode was positioned near the plant roots to benefit from nutrient-rich microbial interactions, while the cathode was placed at the periphery, away from the rhizosphere. Electricity generation occurred at the bioanode through microbial oxidation of photosynthesis-derived glucose, with oxygen reduction taking place at the cathode. The influence of photosynthetic activity on cell performance was evaluated under different illumination conditions and in the absence of the plant. The results demonstrated that photosynthesis markedly enhanced PBFC efficiency, yielding a maximum power density of 330 nW/cm² under high Light intensity, compared to 130 nW/cm² in the dark and 126 nW/cm² without the plant. Despite the inherent limitations of biological systems, an amplification circuit consisting of an operational amplifier, a photovoltaic panel, and a DC–DC boost converter was integrated to overcome the low power output. This modification improved the output voltage to 2670 mV, in contrast to only 91 mV without amplification. Furthermore, the amplified bioelectricity was successfully applied to electrodialysis for the treatment of heavy metal–contaminated water, achieving a desalination efficiency of 28.75% after 3 h. These findings highlight the potential of PBFCs as a sustainable bioenergy source, while also demonstrating their applicability in environmental remediation processes.

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The efficient synthesis of carbon nanotubes from renewable precursors offers a sustainable alternative to conventional, energy-intensive methods. In this work, orange peel waste was converted into multi-walled carbon nanotubes (MWCNTs) through a two-step process involving slow pyrolysis at 300–500 °C followed by microwave-assisted catalytic growth using ferrocene. Nine samples were prepared at different pyrolysis temperatures and ferrocene-to-biochar ratios (1:1, 1:2, and 1:3) to study the effect of precursor carbonization and catalyst balance on CNT yield, concentration, and structure. The highest yield of 0.245 ± 0.015 g/g was obtained for OPCNT 500 1:1, while the lowest yield (0.105 ± 0.010 g/g) was recorded for OPCNT 300 1:3, representing a 57.1% difference. CNT diameters ranged between 76 and 99 nm, confirming MWCNT formation. UV–vis analysis revealed maximum CNT concentration of 1.15 × 10⁻⁴ mol/L for OPCNT 500 1:1, whereas the lowest concentration (1.9 × 10⁻⁵ mol/L) was observed for OPCNT 300 1:3. Raman spectroscopy confirmed high graphitization (I_D/I_G < 1), while XRD and FESEM verified tubular morphology and crystalline graphitic features. EDX analysis further confirmed carbon dominance with minor catalyst residues. These findings highlight the possibility of developing sustainable, low-cost, and energy-efficient nanomaterial synthesis pathways by utilizing abundant fruit waste residue as renewable carbon sources.

The extensive use of fossil fuels for producing plastics poses global warming and plastic pollution. Thus, it has become essential to develop sustainable bioplastics derived from renewable biomass. Nowadays, the world’s most rapidly evolving bio-based polymer is polylactic acid (PLA). The necessary key material for producing biodegradable plastic—PLA is lactic acid (LA). LA is an essential organic acid with several industrial applications known to be produced during fermentation. LA can be produced effectively by fermentation, but it has to be improved to reduce production costs and market rates. The study aimed to produce PLA from food waste (FW) using probiotic bacteria. Lactic acid bacteria (LAB) are harmless microorganisms that may produce a variety of chemicals associated with health benefits. Five Lactobacillus isolates were obtained from FW and were checked for their probiotic properties. Upstream process factors such as substrate concentration, agitation, static condition, pH, and fermentation period were investigated. After 48 h at pH 5.0, a strain of Lactiplantibacillus plantarum FWLB4 generated 26.3 ± 0.3 g/L of LA using 90% of the substrate FW for microbial LA production. n-butanol and ammonium sulphate (chaotropic salt) were used in a phase partitioning technique to extract LA from the fermentation broth. The melt polycondensation of LA to PLA was catalyzed by stannous octoate. To extensively analyze the structure and properties of obtained LA and PLA, different characterizations such as FTIR, NMR (¹H & ¹³C), DSC, and TGA were employed.

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