Biomass Conversion and Biorefinery最新文献

This study presents a novel, sustainable protocol for the integrated fractionation of Arctic brown algae (Fucus vesiculosus) biomass using choline chloride-based natural deep eutectic solvents (NADES). For the first time, we demonstrate the selective fractionation of algal biomass into four high-value fractions via a green dissolution process followed by two step anti-solvent precipitation with acetone:water (10:1) mixture, water and hexane extraction. The selectivity was confirmed by the distinct separation into alginates (~ 30 wt.%), polysaccharides (~ 30 wt.%), polyphenols (~ 10 wt.%), and fatty acids (~ 2 wt.%) fractions with the predominant composition of each fraction verified by FTIR, NMR, and HRMS. The acetone–water system enabled critical separation of bioactive polyphenols and fatty acids from condensed aromatic structures, enhancing their potential functional value. The proposed approach establishes a foundation for scalable, zero-waste algal processing, with future research directed toward solvent recycling, detailed structural characterization of fractions, and evaluation of their bioactivity for pharmaceutical, cosmetic, and food applications.

This study explores the potential of converting Areca catechu leaf waste biomass into valuable paper/board material using the refiner mechanical pulping (RMP) process, followed by a bio-coating composed of chitosan and beeswax to enhance its mechanical strength and barrier properties for potential applications. The effects of these coatings on the physical, mechanical strength, and barrier properties of the paper were assessed using TAPPI standard methods. The results demonstrated significant improvements in mechanical strength properties for the paper coated with 20% bio-coating, which has a thickness of around 20 microns. Compared to uncoated paper, the coated paper exhibited increases in tensile strength index, tear index, and burst index by approximately 21.9%, 43.9%, and 36.84%, respectively. Additionally, the Cobb₆₀ value of the coated paper decreased by about 96.5%, and its oil resistance time exceeded 1800 s, per TAPPI standards. Biodegradation tests indicated that uncoated paper fully degraded in 30 days, while the coated paper degraded approximately 100% in 60 days. Paper sheets produced from RMP-processed areca leaf waste, blended with kraft pulp from the same material bio-coated, offer a promising eco-friendly solution for biodegradable packaging paper/board, meeting IS 6615:1972 standards.

Miscanthus lutarioriparius (ML) is an ideal energy crop due to its high biomass production and cellulose quality. In this study, ML was pretreated with formic acid combined with alkaline hydrogen peroxide (FA-AHP) to enhance glucose concentration during enzymatic hydrolysis. The physicochemical properties and enzymatic hydrolysis efficiency of ML lignocellulose following different pretreatment methods were investigated. The physicochemical results showed that cellulose fractionated by FA-AHP pretreatment (FA-AHP-C) became more hydrophilic, with a reduction in the degree of polymerization from 1,040 (untreated ML) to 515 (FA-AHP-C). Compared to untreated ML, FA-AHP-C showed a 9.49-fold increase in cellulose conversion and a 20.61-fold increase in glucose concentration during enzymatic hydrolysis. For FA-AHP-C, the maximum cellulose conversion reached 99.86% at 5% solid loading, with optimal enzyme dosing at 10 FPU/g. Tween-80 had the greatest impact on improving enzymatic hydrolysis efficiency, increasing the cellulose conversion by 7.5% at 20% solid loading. The highest glucose concentration of FA-AHP-C reached 223.04 g/L under 34% solid loading through a fed-batch enzymatic hydrolysis process. This research offers technical support for producing high glucose concentration from ML.

Lime peels, often discarded as waste in the food and beverages industry, encompass a vast range of indispensable bioactive compounds showing various therapeutic properties (e.g., antioxidant, bacteriostatic, antifungal, cytotoxic activities, etc.). This study aimed to optimize the drying conditions of Citrus aurantifolia peels dried using traditional (sun drying) and alternative drying methods (tray drying and vacuum drying), extract essential oil using hydro-distillation, and enhance its stability through nano-encapsulation with polyethylene glycol (PEG) 4000. Tray drying at 50 °C preserved the highest levels of phenolics (73.41 ± 0.15 mg GAE/g), flavonoids (45.52 ± 0.21 mg QE/g), radical activity (84.91 ± 0.09%), and ascorbic acid (136.54 ± 0.27 mg/100 g). Hydro-distillation yielded 1.3% (v/v) essential oil, which was characterized using NMR and FTIR analysis. Nano-encapsulation achieved an encapsulation efficiency of 51.1 ± 1.19%, improving stability, bioactivity, and showed antimicrobial activity against pathogenic microbes. These findings support the sustainable utilization of lime peel waste in food and pharmaceutical applications.

Proteases are vital industrial enzymes, contributing approximately 60% of the global enzyme market, by facilitating protein hydrolysis. Fruit peels, a major agricultural waste, offer a sustainable alternative for commercial enzyme production. This study investigates the proteases extracted from the peels of Punica granatum, Musa acuminata, Carica papaya, and Ananas comosus, with a primary focus on determining their optimal pH, temperature, and substrate specificity. Additionally, Kₘ and Vₘₐₓ kinetics were assessed to characterize their catalytic efficiency. Optimal proteolytic activity was observed at pH 8 and 30 °C for P. granatum, pH 7 and 30 °C for M. acuminata, pH 8 and 30 °C for C. papaya, and pH 7 and 50 °C for A. comosus. substrate specificity of protease was assessed using casein, fish meal, soybean meal, black soldier fly larvae, bovine serum albumin, and egg albumin, revealing broad applicability, especially in P. granatum peels. The stability of P. granatum proteases across substrates suggests multiple isoforms or a flexible active site. Kinetic analysis using Lineweaver-Burk plots revealed Vmax and K_M values of 8.45 µmol/min/mL and 3.81 µM (P. granatum), 4.56 µmol/min/mL and 10.08 µM (M. acuminata), 2.98 µmol/min/mL and 2.84 µM (C. papaya), and 2.97 µmol/min/mL and 11.38 µM (A. comosus) respectively. Among the tested fruit peels, P. granatum exhibited the highest reaction rate, while C. papaya demonstrated the highest substrate affinity, making them as promising candidates for feed supplementation and industrial enzyme applications. The broad substrate specificity and high catalytic efficiency of P. granatum further reinforce its potential for use in feed formulations, enhancing protein hydrolysis and improving nutrient availability. These findings highlight the significant potential of fruit peel-derived proteases in promoting sustainable enzyme production and advancing bioeconomic applications.

Biomass gasification is a complex process influenced by various factors such as gasifier operating conditions; biomass feed characteristics, and choice of gasifier design. Conducting experimental studies to understand these interactions can be challenging and expensive due to the multitude of variables involved. To address this, simulation and modeling tools play a crucial role in predicting gasification outcomes. This study employs multivariate analysis tools, namely Principal Component Regression (PCR), Partial Least Square Regression (PLSR), and Artificial Neural Network (ANN), to model and simulate the air gasification of biomass using training dataset (n = 170). The objective of the present analysis is to predict the key product gas characteristics, specifically output gas composition (CO, CO₂, CH₄, H₂, N₂) in volume % and its Lower Heating Value in MJ/Nm³. Training data from various literature sources are utilized, incorporating biomass characteristics such as proximate, ultimate analysis, Higher Heating Value in MJ/Kg, and the operating variable of equivalence ratio (ER). A new set of data (n = 21) excluding the training dataset are used for the model validation. Validation results indicate that, the model predicted parameters are within an error margin of 10%. Evaluation metrics, including Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), and one-tail t-test, are applied to assess the accuracy of the models on the validation dataset. The values of RMSE for PCR, PLSR, and ANN models are (0.47766, 0.46022, 0.12621, 1.81209, 0.67679, 0.14601), (0.20718, 0.49909, 0.06744, 0.96549, 0.6324, 0.07951) and (0.22907, 0.53613, 0.21085, 0.5469, 0.13152, 0.01326) for predicted values, respectively.

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To address the ecological problem caused by the accumulation of green tide Enteromorpha prolifera and the challenge of remediating organic pollutants in water bodies, this study utilized Enteromorpha prolifera as raw materials to synthesize a novel nitrogen-doped biochar (NBPBC) catalyst through ball-milling and pyrolysis. The resulting catalyst was applied to activate peroxymonosulfate (PMS) for antibiotic tetracycline (TC) degradation. The optimized NBPBC exhibited a large specific surface area (62.0022 m²/g) and a high content of graphitic nitrogen. Experimental results showed that the NBPBC/PMS system achieved 100% removal efficiency towards TC within 60 min with a rate constant k = 0.06629 min^− 1, significantly outperforming systems without ball-milling or nitrogen doping. Additionally, NBPBC maintained good a catalytic activity and stability after six cycles, with the TC degradation efficiency remaining above 80%. Mechanistic studies revealed that the catalytic mechanism was dominated by ∙O₂⁻, with synergistic contributions from ∙OH, ¹O₂ and SO₄∙⁻. This work achieves the high-value utilization of Enteromorpha prolifera waste and provides an efficient strategy for aquatic organic pollutant remediation, offering a dual-win solution to ecological and environmental challenges.

Graphical abstract

A novel N-doped biochar catalyst based on Enteromorpha prolifera was synthesized through a ball-milling and single-step pyrolysis method, which can effectively activate PMS to realize the rapid degradation of organic pollutants and the high-value utilization of Enteromorpha prolifera.

Coconut shell was pyrolyzed using solar energy to produce biochar and evaluate its effects on methane production during anaerobic digestion (AD) of swine wastewater (SW). The study investigated the physicochemical properties of biochars generated at 400 °C, 600 °C, and 800 °C. The biochar obtained at a high temperature (800 °C) showed distinctive properties compared to the other biochars: the largest surface area (134 m²/g) and oxygen functional groups linked to turbostratic graphite clusters that could act as pH buffers, leading to high methane productivity. This biochar promoted the highest organic matter conversion to methane with a conversion rate of 72% and to 890 mL CH₄/L SW, which is 2.4-fold higher than the control without material. In parallel, the 800 °C biochar promoted the highest net production and consumption of volatile fatty acids (VFA), removal of chemical oxygen demand (COD) (82%), and methane yield (290 mL CH₄/g COD). The theoretical techno-energetic analysis indicates that the combination of solar pyrolysis with AD showed an increase of up to 33 times in the energy produced with biochar obtained at 800 °C, compared with anaerobic digestion without biochar, representing an alternative for the current energy demand.

Graphical Abstract

Due to the heterogeneous nature of lignin, its depolymerization into value-added chemicals is challenging, leading to a broad product spectrum and low yields of desired products. In this study, we explore the synergistic effects of noble metal catalysts and chloride salt-based deep eutectic solvents (DES) for the direct depolymerization of lignin into aromatic compounds. The combination of Ru/C and CuCl₂-based DES achieved the highest yields of aromatic monomer compounds, including 4-propyl-2,6-dimethoxyphenol, 3-(4-hydroxyphenyl) propionate, and methyl 3-(4-hydroxy-3-methoxyphenyl) propionate. The impact of reaction conditions on lignin depolymerization efficiency was also investigated. The highest conversion rate of 73.85%, 21.04% and 17.26% for 4-propyl-2, 6-dimethoxyphenol, 3-(4-hydroxyphenyl) propionate and methyl 3-(4-hydroxy-3-methoxyphenyl) propionate, respectively, were obtained under the optimized reaction system with 0.5 g catalyst, under the conditions of 2 MPa H₂ and 150 °C for 3 h. A noble metal catalyst recovery rate of 94% was achieved after four cycles, with a remaining conversion efficiency of 63.1%. The mechanism for the direct depolymerization of lignin to 4-propyl-2,6-dimethoxyphenol in this study was also proposed.

The carbon sequestration potential of natural and restored mangrove ecosystems was assessed in Tamil Nadu and Andhra Pradesh, India. A total of eight mangrove species were recorded in the natural vegetation and the restored mangrove site. Hydrological factors, including salinity, temperature, dissolved oxygen, and pH, were measured, along with tree density, basal area, aboveground and belowground biomass, and carbon stock. The mean tree density of mangroves in the natural stand was 4199.5 ± 1348.37 trees ha^− 1, and the restored site had an average of 4523.3 ± 654.02 trees ha^− 1. The basal area of mangroves is from 19.24 ± 15.73 m² to 66.58 ± 84.57 ha^− 1 across both vegetation types. The average aboveground carbon stock for natural mangroves was 260.4 ± 114.15 Mg C ha^− 1, whereas for the restored site, the average aboveground carbon stock was 49.21 ± 19.26 Mg C ha^− 1. The total average vegetative carbon stock in natural vegetation was 346.3 ± 152.04 Mg C ha^− 1, and in the restored area, the mean value was 69.45 ± 26.99 Mg C ha^− 1. The natural vegetation exhibited a mean soil organic carbon (SOC) of 11.39 ± 8.4 Mg C ha ^− 1 and the restored site had an average value of 7.22 ± 5.33 Mg C ha-¹. The SOC content was significantly associated with the species dominance index (p < 0.01). A significant variation in total vegetative carbon was observed among the sampling sites, with the natural site showing Kruskal–Wallis test (Hc) = 29.4 (p < 0.001) and the restored site showing Hc = 18.51 (p < 0.001).