Biomass Conversion and Biorefinery最新文献

Alcohol fermentation in batch culture was carried out to determine the behavior of biomass transport phenomena along the bioreactor. The applied methodology utilized both a one-dimensional theoretical modeling of biomass transfer in a tubular bioreactor associated with alcohol fermentation in batch culture and an experimental approach based on a triplicate run. The model’s predictions are validated against experimental data obtained from a real bioreactor system, demonstrating its accuracy and reliability for practical applications. Furthermore, the model solution demonstrated that the converging of biomass concentration in the 5-point nodal bioreactor depends on the values of the model parameters, namely the maximum specific growth rate (μ_max), the diffusivity coefficient (D), dimensionless coefficient (α) and reciprocal of doubling time (β). The experimental results show that distribution of biomass concentration along the reactor column is in the range between 3.40 and 3.62 g_DW L⁻¹ with an average value of about 3.52 g_DW L⁻¹. Furthermore, the average final ethanol concentration is about 58 g L⁻¹ after an average fermentation time of about 35 h and an average starting sugar concentration of about 65 g L⁻¹.

To deal with the high lignin content of horse manure in the methanization process, eco-fractionation and chemical modification strategies of lignin have been proposed, opening up prospects for new lignin-based thermoplastic materials. Firstly, a strategy inspired by the biochemical pathway and based on ionic liquid pretreatment, with appropriate recyclability and biodegradability characteristics, was implemented. A sugar-enriched fraction was recovered after enzymatic hydrolysis and a lignin-enriched fraction was isolated (80% w/w). The second strategy was an organosolv process, using the easily biodegradable 2-methyltetrahydrofurane-3-one, allowing selective extraction of a lignin-enriched fraction (> 80% w/w almost sugar-free) and a partially delignified sugar solid fraction. H/G/S ratios and aryl-ether linkages showed little difference for the two isolated lignins, which may be responsible for the more successful palladium-catalyzed telomerization of 1,3-butadiene on the phenolic and carboxylic hydroxyls of organosolv lignin. Whatever the strategy used, carbohydrate fractions showed competitive biochemical methane potential for methanization.

The inadequate conversion of rice husk (RH) into biogas due to its recalcitrant lignocellulosic structure and high silica content necessitates the requirement of pretreatment prior to anaerobic digestion (AD) of RH. This study evaluated the impact of hydrothermal pretreatment on the solubilization of complex lignocellulosic matrix of RH and its subsequent influence on biogas and biomethane yield. The RH was pretreated at six different temperature levels between 200 and 250 °C, at an interval of 10 °C with 20% total solids (TS) loading and retention time of 10 min. The solubilization of RH at different pretreatment temperatures was evaluated by characterizing the liquid and solid fractions of the pretreated RH. The AD of untreated and pretreated RH revealed that the highest biogas and biomethane yields of 355 ± 34 mL/g VS_input and 153 ± 20 mL/g VS_input were observed for RH pretreated at 230 °C, 4.5 and 5.7 times higher than untreated RH. This increase in biogas and biomethane yield for RH230 was confirmed by observing enhanced volatile solid (VS) reduction (38.72%) and biodegradability (39.40%) compared to VS reduction (8.87%) and biodegradability (7.02%) for untreated RH. Further, correlation matrix analysis revealed a strong relation between pretreatment temperature and its severity on the fate of utilizing RH as an AD substrate and obtaining maximal biogas yield. Conclusively, pretreatment up to 230 °C could be recommended to enhance biogas and biomethane yield from RH effectively. Further investigation in pilot-scale reactors is recommended to validate these findings.

Xylanolytic enzymes cleave the β-1,4-glycosidic bonds within xylan, the primary polymer found in the hemicellulosic fraction of lignocellulosic biomass, converting it into xylose. This enzymatic class holds significant applications in various biotechnological processes, particularly within the pharmaceutical, food, and bioenergy industries. This study focuses on a cost-effective method for producing a xylanolytic blend (XB) through the solid-state fermentation of the low-cost coffee husk (CH) by-product, using Penicillium roqueforti ATCC 10110. Optimal bioprocess conditions were identified at 59% humidity and 16 °C, resulting in xylanolytic activity of 13.20 U/g. The XB exhibited favorable thermostability at 40 °C, with maximum activity at 50 °C and pH 5. The effect of solvents revealed significantly enhanced activity with dichloromethane and hexane. The presence of metallic salts, including Pb(C₂H₃O₂), Na₂CO₃, KCl, FeSO₄, CuSO₄, MgSO₄, and ZnSO₄, led to more than a 100% increase in enzyme activity, with Na₂CO₃ demonstrating an outstanding 229.9% enhancement. Similarly, other organic compounds such as EDTA, SDS, Triton X-100, and Trolox significantly increased enzymatic activity (+ 286.69% for Triton X-100), while other salts such as CaCO₃, MgCl₂, and Al(NO₃)₃ led to inhibition. These results differ from previous reports of xylanases from this microorganism and position the developed XB as a promising sustainable catalyst for the saccharification of CH. The bio-based recycling approach elevates the value of CH and proposes an alternative to conventional fertilizer use. The basis developed here serves as guidelines for further investigations exploring the XB application in high-grade pharmaceuticals, food, and bioenergy in large-scale scenarios.

Acetamiprid (ACMP) is a significant neonicotinoid insecticide recognized for its efficacy against various insects. The increasing use of insecticides in agriculture substantially threatens water resources and ecosystems. Thus, effectively removing pesticide residues is crucial to mitigating the adverse effects of conventional agricultural practices. This study aims to enhance the elimination of ACMP from water using a dual approach: nanofiltration and activated carbon derived from silver berry seeds. Various physicochemical parameters, including contact time, AC dose, agitation speed, and the initial pH, were examined to understand their impact on the ACMP removal process through adsorption. Remarkably, a 97% removal of ACMP was achieved under a contact time of 90 min, an agitation speed of 300 rpm, and an AC dosage of 500 mg·L⁻¹. The adsorption equilibrium data were modeled using the Freundlich, Langmuir, and Temkin isotherm models, with the Langmuir model providing the best fit and indicating a maximum adsorption capacity of 193.92 mg·g⁻¹. Kinetic studies with PFO and PSO models showed that the PSO model provided an excellent fit with high regression coefficients (R²). Thermodynamic analysis confirmed that the adsorption process is both endothermic and spontaneous. Concurrently, the nanofiltration process was optimized by examining the initial pH, recirculation flow rate, initial ACMP concentration, and the presence of salts. Results indicated a remarkable removal efficiency of 97.5% at a 6-bar transmembrane pressure and 750 mL·min⁻¹ as a recirculation flow rate. This study validates nanofiltration for ACMP removal, offering insights into mitigating pesticide residues’ environmental impact

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Active biodegradable films offer a promising solution to the issue of food contamination and loss by providing suitable packaging materials that help maintain food quality and extend shelf life. This study focused on optimizing and characterizing active bio-plastic films made from modified tamarind seed starch enriched with red grape pomace extract. The physical, mechanical, barrier, thermal, antioxidant, and antibacterial qualities of the films were assessed. Using response surface methodology, modified tamarind seed starch (MTSC), glycerol (GC), and red grape pomace extract concentration (RGPEC) were optimized to values of 3.5% w/v, 25% w/w, and 6% w/w, respectively, to develop active bio-plastic film using solvent-casting techniques. The film’s optimal tensile strength was improved significantly (p < 0.05) from 11.87 ± 0.02 MPa for pure tamarind seed starch bio-plastic to 12.77 ± 0.02 MPa for active bio-plastic film, demonstrating improved the mechanical characteristics. When compared to the pure tamarind seed starch-based film, which had a water vapor permeability of 2.4 × 10^–10 ± 0.005 gm⁻¹h⁻¹Pa⁻¹, the optimized film enriched with red grape pomace had a water vapor permeability of 2.35 × 10^–10 ± 0.001 gm⁻¹h⁻¹Pa⁻¹, which was notable (p < 0.05). The grape pomace extract exhibited higher antioxidant activity (IC₅₀ = 280.5 ± 0.042 µg mL⁻¹) compared to the active film (IC₅₀ = 556 ± 0.038 µg mL⁻¹) and non-active film (IC₅₀ = 320067.3 ± 0.024 µg mL⁻¹) in the DPPH assay. The extract also had larger zone of inhibition values against Staphylococcus aureus (10.00 ± 0.01 mm) in contrast to the active bio-plastic film (8.2 ± 0.02 mm). For Escherichia coli, the values were 8.5 ± 0.03 mm for the extract and 7.4 ± 0.05 mm for the active film. In non-active films (film without GPE), no antimicrobial activity was seen. The active bio-plastic film decomposed to about 63% of its original weight after 30 days. Overall, the active film exhibited positive mechanical, barrier, antibacterial, and antioxidant properties compared with pure tamarind seed starch film, making it appropriate for applications in food packaging.

Epoxidized vegetable oils have the potential to replace polymers from petroleum sources. This paper investigates the effect of process parameters on the epoxidation of neem oil with applied Amberlite IR-120H. The method chosen for this study is forming performic acid as an oxidizing agent by mixing hydrogen peroxide with formic acid to form performic acid, where the molar ratio against neem oil varies accordingly. The highest relative conversion (51.5%) to oxirane is obtained when the formic acid/neem oil molar ratio is 1:1, hydrogen peroxide/neem oil is 4:1, the reaction temperature is maintained at 70 °C, and the stirring speed is maintained at 300 rpm with 1 g of catalyst loading. Both neem oil and its epoxide form are analyzed by FTIR, where the formation of an oxirane ring is shown at a wavenumber of 1240 cm⁻¹. Rate constant for epoxidation, ({k}_{2}) is 4.95 (mol/L⋅min), calculated by kinetic modelling and aligned with other researchers. Kinetic modelling also shows that simulation and experiment are in acceptable disparity, considering that a few assumptions had been made.

Global warming and climate change condition are prevailing due to over exploitations of natural resources like fossil fuels, heavy metals, and dumping of wastages in open space. To bring solution to these less dense composite materials using waste biomass is now researched widely by scientists under various applications. The mechanical, tribological, wear, water absorption, and thermal conductivity properties of composite materials reinforced with bronze nanoparticles and areca fiber coated with vinyl silane are investigated in this research work. The novelty of this research study is to investigate how the composite’s characteristics were affected by the vinyl silane–treated bronze nanoparticle. Using a hand layup technique, the fabrication was cured for 24 h at ambient temperature and then post-cured at 120 °C. The AB2 (Areca fiber of 40 vol.%, Bronze nanoparticle of 3 vol.%) composite demonstrated stronger mechanical properties, including a tensile strength of 37.2%, a flexural strength of 22.4%, and an izod impact strength of 36.6% when compared to fiber- and matrix-reinforced base composite AB0 (areca fiber 40 vol.%, resin 60 vol.%, bronze nanoparticle 0 vol.%). In contrast, the AB3 composite displayed remarkable hardness at 84 Shore-D, outstanding wear resistance at 0.011 mm³/Nm, superior thermal conductivity at 0.212 W/mK, and excellent hydrophobicity at 0.12%. Further, when compared to the thermal conductivity of AB3 composite shows 34.2% higher than the thermal conductivity of base composite AB0. Similar such increase in values is attained in other composites compared to AB0 composite. Furthermore, vinyl silane–treated bronze nanoparticles are present in greater volume fractions in AB2 and AB3, which increase reinforcement inside the composite matrix and improve mechanical characteristics. The SEM (scanning electron microscopy) results corroborate that the vinyl silane treatment improved the bond strength of the fiber, filler, and resin. The reinforcement of vinyl silane–treated metallic nanoparticle and natural fiber reinforcement shows better mechanical, wear resistance, and thermal stability property which could be utilized in areas such as automotive, aerospace, defense, and structural applications.

This study explores enhancing xylooligosaccharides (XOS) production as a novel source of antioxidants by utilizing autoclave-assisted oxalic acid pretreatment of sugarcane trash, specifically its tops and leaves. The study aims to optimize the concentration of oxalic acid and the duration of heating to maximize XOS yield and antioxidant activity, while also considering phenolic content as a contributing factor. Initially, through a One Factor at a Time (OFAT) approach, different concentrations of oxalic acid (ranging from 0.5 to 3%) were tested with a consistent 30-min heating period. The optimal XOS level of 6.45 g/L and 70.23% antioxidant activity was achieved at a 1% acid concentration. Subsequently, the focus shifted to optimizing heating durations (30, 45, and 60 min) at the identified optimal acid concentration. The highest XOS concentration of 6.45 g/L was observed at 30 min, while the peak antioxidant activity of 73.32% was attained at 60 min. Moreover, the total phenolic content of XOS, which contributes to its antioxidant properties, was found to be in the range of 9–10 mg GAE/100 mg. These findings highlight the potential of sugarcane trash as a new biomass resource for the production of antioxidant-rich XOS.

Industrial wastewater poses a significant threat to human health and the environment. Numerous treatment methods have been developed to mitigate harmful compounds. The production of multifunctional titanium oxide nanoparticles (TiO₂-NPs) for wastewater treatment through green synthesis is a desirable alternative to conventional methods. This study reports using Echinops echinatus leaves (EES) as an effective bio-reductant for the green synthesis of TiO₂-NPs. A simple and eco-friendly process with low reaction time and temperature was adopted for the EES-mediated synthesis of TiO₂-NPs. Various spectroscopic and microscopic techniques were used to characterize the synthesized nanoparticles. The UV–visible spectrophotometer spectra showed an absorbance peak at 289 nm and a bandgap of 2.91 eV. SEM and XRD revealed the nanoparticles’ crystal nature, size, and spherical morphology. HR-TEM indicated an average particle size of 36 nm with a spherical shape. Energy-dispersive X-ray (EDX) spectra confirmed the presence of titanium. Fourier transform infrared (FTIR) spectroscopy identified the fundamental biomolecules responsible for reducing and stabilizing the TiO₂ nanoparticles. The synthesized nanoparticles were developed as photocatalysts for treating trypan blue dye under visible light irradiation, achieving a rapid decomposition rate with 84% degradation efficiency and catalyst reusability. The radical experiment that was studied identified h⁺ and OH* radicals as the more reactive species. The catalytic potential of EES-TiO₂ NPs was further examined for converting 4-nitrophenol to 4-aminophenol, with a 98% conversion rate in an alkaline medium. UV–vis spectroscopy showed a decrease rate of k = 0.011 min⁻¹ during the catalytic conversion. Additionally, EES-TiO₂ NPs demonstrated significant antibacterial effects on pathogenic bacteria, as measured by the zone of inhibition in the disc diffusion method. The findings suggest that the synthesized EES-TiO₂ nanoparticles hold promise for various environmental and antipathogenic applications.

Graphical Abstract

A schematic representation of the green synthesis of TiO₂ nanoparticles for photocatalysis and antimicrobial activity.