Biomass Conversion and Biorefinery最新文献

Lactic acid is a high-value foundational chemical with applications in the manufacturing of pharmaceuticals, polymers and solvents. Microbial machineries offer a green alternative to chemical synthesis which can efficiently valorise complex organic substrate into lactic acid, however high substrate cost hinder its practical significance. A substantial quantity of food is wasted which raises the issue of food security and environmental concern. Concurrently, food waste being rich in carbohydrate and growth factors, it emerges as a promising and renewable feedstock for lactic acid fermentation. Therefore, this study takes the opportunity to explore the viability of lactic acid production from food waste utilizing Lactobacillus amylophilus GV6. The influencing process variables were optimized by central composite design based response surface methodology and bayesian regularization based artificial neural network models. The residual post-fermented biomass was channelled to biochar production for removal of methylene blue and crystal violet. The KOH-activation has appreciably increased the BET surface area, median pore width and pore volume from 96.6 to 401.1 m²/g, 1.617 to 2.630 nm and 0.209 to 0.680 cm³/g, respectively. The adsorption kinetics suggested that adsorption followed pseudo second order kinetics whereas, adsorption isotherm followed Freundlich and Temkin model suggesting multi-layer adsorption. Hence, this research demonstrates that utilizing food waste as a sustainable resource can be employed in the production of valuable platform chemicals like lactic acid through microbial fermentation. Additionally, the residual post-fermented biomass can be directed towards cost-effective adsorbents for effectively removing toxic dyes and other impurities from wastewater.

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This study presents a novel methodology for hydrogen production via biomass pyrolysis using industrial solid waste-derived catalysts, providing an innovative pathway to facilitate the conversion of highly valuable biomass resources. In this study, the effects of four typical industrial solid wastes (coal ash, carbide slag, red mud and steel slag) as Ni-based catalyst carriers on the pyrolysis gas composition and yield of pine wood chips were investigated. The experimental data reveal that the integration of fly ash as a support material for Ni (Ni_0.1/CA) significantly enhances catalyst efficiency, resulting in the highest total gas yield. Compared to other supports, the catalyst incorporating calcium carbide residue (Ni_0.1/CS) exhibits superior hydrogen generation performance, achieving a maximum H₂ yield of 283.40 mL/g _biomass with a H₂ concentration of 64.5 vol%. To explore the effect of nickel loading on hydrogen production efficiency, the performance of Ni loading onto calcium carbide residue was systematically assessed. Experimental results demonstrated that Ni_0.1/CS represents the optimal loading configuration, exhibiting superior catalytic properties. Finally, the effect of pyrolysis reaction temperature on gaseous pyrolysis products was methodically assessed, followed by an evaluation of catalyst stability under cyclic conditions at the optimal pyrolysis temperature of 600 ℃. The catalyst consistently achieved a hydrogen yield of 197.78 mL/g _biomass over five cycles, retaining 71.19% of its initial performance. In conclusion, this study develops an innovative, environmentally sustainable, and economically viable approach that effectively integrates low-value biomass with industrial solid waste, thereby proposing a cost-effective, eco-friendly technological framework for the distributed production of green hydrogen.

In view of the dynamic nature of energy demands and the increasing of energy consumption, this study was conducted to analyze the thermal degradation properties of rubber shells (RS) and rubber cakes (RC) lignocellulosic biomasses. The aim of this study is to evaluate their pyrolytic performance for bioenergy production. Preliminary characterizations, including proximate analysis, EDX, SEM, FT-IR, ¹³C NMR and XRD, were conducted to assess their suitability for pyrolysis. Proximate analysis revealed that RC has a high volatile content. In addition, thermo gravimetric analyses were performed at three heating rates (4, 8, and 16 °C/min) in an inert environment. TGA analysis showed that the maximum devolatilisation temperature during the decomposition of both types of biomass is between 210 and 480 °C. Kinetic and thermodynamic parameters of the activated complex formation were calculated using Vyazovkin models, differential method (Starink) and two isoconversion models: Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO). According to these approaches, the activation energy was determined to be 94.251 and 108.019 kJ/mol, and 327.494 and 330.520 kJ/mol for RS and RC, respectively. The Gibbs free energy results were 193.493 and 195.661 kJ/mol, and 309.743 and 212.520 kJ/mol, respectively. The values for the enthalpy change (ΔH) were 88.467 and 102.235 kJ/mol, and 321.067 and 324.095 kJ/mol for RS and RC, respectively. Coats-Redfern claims that the high R² values observed in models F, A, G and D suggest that biomass pyrolysis is the result of multiple sequential and/or concurrent processes rather than a single kinetic mechanism. Pyrolysis, which transitions from chemical to diffusive control, is therefore considered to be multi-mechanistic. This illustrates the inherent complexity and diversity of biomass. These results clearly demonstrate the significant potential of these biomasses for bioenergy production.

Pectinase is essential in various industrial applications, such as food processing, textile manufacturing, and paper biodeinking. Nevertheless, enhancing its production poses a difficulty owing to the impact of many bioprocess variables. This research utilizes Taguchi statistical method to optimize pectinase synthesis by Aspergillus niger KW02, employing orange peel as a substrate in submerged fermentation, and the resulting pectinase was evaluated for biodeinking potential and green synthesis of selenium nanoparticles (SeNPs). The SeNPs were characterized using UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, and transmission electron microscopy, and subsequently evaluated for biomedical applications. The L9 orthogonal array of Taguchi optimization improved pectinase yield by 4.35-fold culminating in 890.60 U/ml. The crude pectinase attained ink removal effectiveness of 83.80%, and also facilitated the green synthesis of PFN-SeNPs. The colloidal SeNPs was orange hue and spherical-shaped with λ_max of 264 nm and sizes of 62.09–64.76 nm. Until now, there is paucity of information on nanoparticles synthesis using pectinase. The synthesized PFN-SeNPs showed substantial antibacterial efficacy against Salmonella enterica and Klebsiella oxytoca (20.10–20.80 mm), and total fungal suppression against Aspergillus flavus, Aspergillus niger, and Penicillium sp. Additionally, the nanoparticles scavenged DPPH by 52.30% and displayed 100% anticoagulant activity. These findings demonstrated a cost-effective and sustainable method for pectinase and selenium nanoparticles production for sustainable development. Pectinase-inspired synthesis of nanoparticles adds to the advances in enzyme nanobiotechnology.

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The study investigates the potential of chemically activated biochar derived from rubber wood sawdust (NARSB) as an effective adsorbent for the removal of ciprofloxacin (CIP) from aqueous solutions. The surface properties, functional groups, and surface area of biochar are enhanced by NaOH activation, as shown by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and BET, leading to improved CIP adsorption. SEM images showed moderate ridges and a highly porous surface, while EDX analysis confirmed the presence of carbon (C), oxygen (O), and sodium (Na) on the surface, supporting the success of the activation process. XRD analysis identified inorganic components, including SiO₂, CaO, and NaO, and demonstrated the characteristic graphite (002) structure of aromatic layers. The BET surface area of NARSB was 81.26 m²/g, with a pore volume of 0.182 cc/g. Thermal analysis showed that NARSB exhibits good thermal stability, with significant weight loss occurring between 200 °C and 450 °C. The optimization of pH, NARSB dosage, stirring time, and initial CIP concentration resulted in 85.97% maximum removal efficiency at pH 3.0, 120 min stirring, 1.0 g/L adsorbent, and 10 mg/L CIP. At pH 3.0, the protonated NARSB surface and cationic CIP attract each other, promoting maximum adsorption. The adsorption of CIP on NARSB also correlated with its hydrophobicity, while the aromatic structure of NARSB facilitated enhanced π-π interactions. The equilibrium data fit the Langmuir model, indicating a monolayer, homogeneous sorption with a maximum capacity of 57.80 mg/g. Kinetic analysis indicated that the adsorption process adhered to the pseudo-second-order model, with a high correlation coefficient (R² = 0.99). Phytotoxicity tests on Vigna mungo seeds showed that the treated CIP solution promoted longer root growth. The adsorbent also exhibited good reusability after five regeneration cycles. The production cost of NARSB was found to be 7.6 US$/kg, demonstrating that it is an affordable and economically viable activated biochar for practical applications. These findings suggest that NARSB is a promising material for the efficient and cost-effective removal of ciprofloxacin from contaminated water sources.

Biochar prepared from breadfruit seed hull (BFSHBC) was employed as an adsorbent material to remove ciprofloxacin and tartrazine dye from an aqueous solution. The adsorbent was characterized using BET, SEM, XRD, TGA, pH_pzc, and FT-IR to ascertain the functional groups on the adsorbent responsible for the binding of the pollutants. The thermogravimetric analysis indicated a high stability of BFSHBC up to 400 °C. The prepared BFSHBC viewed under scanning electron microscopy revealed a structure with many pores. A pH_pzc of 6.4 was recorded for the prepared carbon-based adsorbent material. We found that the optimum pH for the uptake of ciprofloxacin (CPX) and tartrazine (TZ) was 6.0 and 2.0, respectively. The results of the batch adsorption studies were analysed using different kinetic models, such as film diffusion (FMD), intraparticle diffusion (ITD), pseudo-first-order (PSFO), and pseudo-second-order (PSSO). The R² values of 0.99775 and 0.99876 for CPX and TZ indicated that PSSO and FMD were more suitable for analyzing the experimental data. The Langmuir model provides the best fit among various equilibrium isotherms, including the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. This is evidenced by its higher coefficients of determination (R²) of 0.99759 and 0.99198, along with comparatively smaller sums of squared errors of 0.00615 and 0.0065 for CPX and TZ, respectively, when compared to the other models, suggesting a homogeneous surface of the adsorbent for monolayer adsorption. The maximum adsorption capacity according to the Langmuir isotherm model is 0.115 and 0.169 for CPX and TZ, respectively. The thermodynamic result showed that the adsorption processes were random, feasible, spontaneous, and endothermic on the prepared biochar. The adsorption efficiencies of CPX and TZ indicated no significant reduction after regeneration, demonstrating the suitability of the adsorbent for practical applications.

Bacterial cellulose from SCOBY (BCS) is an extracellular polysaccharide biopolymer produced by microbial fermentation. This study explores BCS production from the by-product of red guava kombucha fermentation. The process yields cellulose membranes that float on the surface, requiring optimization to maximize biosynthesis. Response Surface Methodology (RSM) with Box-Behnken Design (BBD) was applied to enhance production by modifying media composition with key nutrients. The study optimized three parameters: Monosodium glutamate (MSG) (A), citric acid (B), and ethanol (C). The best formulation consisted of 0.100% MSG, 0.150% citric acid, and 0.920% ethanol. The RSM model predicted a BCS yield of 175.40 g/L (wet weight), with a thickness of 0.55 mm, pH 2.755, dissolved protein 1.343 mg/mL, and total reducing sugar of 1516.29 mg/L. Experimental results obtained a yield of 164.83 g/L, thickness of 0.50 mm, pH 2.825, dissolved protein 1.32 mg/mL, and total reducing sugar of 1386.67 mg/L. This study demonstrates the potential of BCS from red guava kombucha for commercial applications. The RSM approach effectively optimized production, showing strong parameter interactions that enhance cellulose yield, making it a promising raw material source.

This study presents a sustainable approach for enhancing the removal efficiency of methyl violet 2B (MV-2B) dye using a novel bio-adsorbent composed of chitosan (CT) and lyophilized Lactobacillus casei (LC) biomass isolated from Yakult^® fermented milk. The LC biomass was then blended with a CT biopolymer to prepare a bio-adsorbent (CTLC). An optimal blending ratio of 50:50 wt% (CTLC-50-50 wt%) between CT and LC was recognized for effective removal of MV-2B. The Box-Behnken design (RSM-BBD) was employed to evaluate the effects of three treatment variables on MV-2B removal: CTLC-50-50 dosage range (0.02–0.1 g/100 mL), contact time (5–60 min), and pH (4 − 10). The BBD design indicates that the maximum removal of MV-2B (88.5%) was attained with the parameters of CTLC-50-50 dosage = 0.1 g/100 mL, pH = 9, and contact time = 56.6 min. Equilibrium and kinetic studies showed that biosorption of MV-2B dye by CTLC-50-50 is described by the Langmuir isotherm and pseudo second order kinetic models. The maximum biosorption capacity (q_max) of CTLC-50-50 for MV-2B was 132.6 mg/g, where dye uptake revealed a favorable and spontaneous thermodynamic process. The proposed biosorption mechanism primarily involves electrostatic interactions, n-π bonding, and hydrogen bonding. This study highlights that the developed CTLC-50-50 bio-adsorbent exhibits a unique formulation and remarkable biosorption properties, making it an effective material for removal of cationic dyes from polluted water.

Essential oil distillation from lemon thyme was studied using steam distillation method. The effects of pre-irrigation and packing material on the yield and essential oil contents were investigated. Both parameters improved the yield and the highest yield values were obtained as 1.737 and 2.213, respectively. The major components carvacrol, p-cymene, thymol and γ-terpinene were detected by GC-MS and carvacrol percent reached to the highest value as 52.58% for 30 ml water and 300 g packing. Dimensionless groups were introduced to explain the dependence of the yield on packing. Four models were offered and applied successfully. The modified Weibull model fits best and the other models converge to the first-order indicating ineffective of resistance constant as a result of the improvement of the yield by the packing material. This result reveals the existence of channel forming and improvement of flow regime. The effect of the pre-irrigation was firstly explained by the swelling mechanism showing that the thyme swelled as relaxation-controlled and increased the yield until a limiting value where a resistance to diffusion occurs after a pre-irrigation value of 40 ml. Temperature has also a contribution on the increase in the yield. Lemon thyme was also characterized by FT-IR and TGA methods.

Biomass refining of lignocellulosic biomass for the production of platform chemicals and biomaterials provides a new avenue for high-value conversion of agroforestry waste. In this study, a green and recyclable choline chloride/pyruvic acid (ChCl/PA) pretreatment was developed for the fractionation of peanut shells (PS), and the solid residues and extracted lignin were measured and characterized. The results showed that DES pretreatment was effective in removing 73.46% hemicellulose and 65.05% lignin under the optimal conditions, most of the cellulose was retained in solid residues (cellulose-rich fractions, RCF). Enzymatic hydrolysis of RCF, the glucose yield was significantly increased by 2.4-fold to 65.06% compared with the raw material (Raw). The DES-extracted lignin (DESL) exhibited a low Mw (1548 g/mol) and a high content of β-O-4′ bonds (42.34%, which is about 70% of that of milled wood lignin). Meanwhile, the utilization of DESL in sunscreens is advantageous due to its excellent UV-shielding properties, high phenolic hydroxyl content (164.83 ± 0.09 mg GAE/100 mg lignin), good antioxidant activity, and light color (WI = 52.09 ± 0.24). This study demonstrates a simple and efficient strategy for the high-value conversion of agroforestry waste, with potential applications in sustainable biorefineries and functional material development.

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