Biomass Conversion and Biorefinery

The rise in environmental apprehensions regarding the disposal of plastic packaging has prompted the advancement of biodegradable polymers. Starch, recognized for its affordability and innate ability to decompose, is emerging as a viable option for food packaging solutions. An important development is the utilization of plant by-products to create starch-based films and coatings, to reduce dependence on traditional starch sources and improve economic and resource effectiveness. This transition highlights a significant shift towards sustainable packaging options in light of worldwide environmental issues. The article comprehensively outlines the various methods for extracting and modifying starch. Additionally, it presents valuable perspectives on producing starch films through the casting method and alternative approaches. The focal point of this retrospect lies in preparing starch films and coatings from various sources of plant waste and byproducts. When combined with other bioactive compounds, these starch films are engineered to exhibit intelligent and active properties, including antioxidant activity, antimicrobial properties, and pH sensitivity. This, in turn, helps to minimize food spoilage. Furthermore, the study thoroughly examines their characterization through parameters such as film thickness, thermogravimetric analysis (TGA), water vapor permeability (WVP), water solubility, film transparency, and biodegradability test. The review concludes by addressing emerging trends, contemporary issues, and future research directions in starch-based packaging. Moreover, it underscores the promising potential of starch films and coatings in circular economy packaging, while also highlighting the importance of additional research to enhance their properties and increase market acceptance.

The quest for sustainable and efficient biofuel production has led to the exploration of various biomass feedstocks. Despite technological advancements, pretreatment remains a major bottleneck in utilizing lignocellulosic biomass at an industrial scale. A green pretreatment, which paths the sustainable development goals, is the need of the hour. Therefore the present study is focused on the development of such green, efficient, and economic pretreatment for an abundantly available Bermuda grass, Cynodon dactylon. This study also evaluated the characteristics of Bermuda grass to assess its potential as a feedstock for biofuel production. The C. dactylon contains 39.13 ± 0.8% cellulose, 19.6 ± 1.74% hemicellulose, and 6.83 ± 1.44% lignin. Among the different pretreatments tested, the steam-assisted acid treatment was found to be effective. Further, the pretreated grass was hydrolyzed using the onsite-produced cellulase cocktails. The optimal pretreatment conditions for the yield of monosaccharides are 47 min, 1.1% (v/v) acid, solid-to-liquid ratio of 33, and enzyme loading ratio of 0.8. Under the optimal conditions, 77.43% of total reducing sugars was observed. The results signify the efficiency of developed pretreatment and also the potential of C. dactylon for biofuel production.

The growing global population is driving up energy demand. The continued reliance on conventional energy sources is contributing to global warming and significant emissions of harmful gases. Conventional energy sources, such as coal, crude oil, and natural gas, commonly used in petrochemical processes, must be replaced with sustainable alternatives. One of the most popular and affordable sources for producing renewable energy and chemicals is lignocellulosic biomass (LCB). Lignocellulosic biomass, which includes agricultural waste, energy crops, and forest residues, is readily available, cost-effective, and provides a sustainable feedstock for bio-based energy and chemical production. To break down the natural structure of lignocellulosic biomass and facilitate the separation of its components for various applications, pretreatment is essential. Conventional pretreatment methods, however, have significant drawbacks; they tend to be toxic, environmentally polluting, and expensive compared to non-conventional approaches. To address these issues, we must shift toward less harmful, eco-friendly strategies. Techniques such as microwave, ultrasound, irradiation, hydrodynamics, and pulsed electric fields are promising alternatives, generating fewer toxic by-products and being more environmentally friendly. This paper explores the benefits, limitations, and mechanisms of specific non-conventional pretreatment methods, as well as the role of lignocellulosic biomass in biomass valorization and the circular economy.

This study investigates the effectiveness of raw pine bark (SB) as a bio-adsorbent for removing crystal violet (CV) dye from aqueous solutions. Batch adsorption experiments were conducted to optimize the adsorption parameters, including pH, adsorbent dosage, contact time, initial dye concentration, and temperature. The physical and chemical properties of pine bark were characterized using various analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and energy-dispersive X-ray spectroscopy (EDS). The results showed that under optimal conditions, a removal efficiency of 82.47% was achieved, with a maximum adsorption capacity of 33.51 mg/g. Thermodynamic analysis revealed a spontaneous adsorption process, with a negative Gibbs free energy value (ΔG° = -33.35 kJ/mol at 298 K). Additionally, pine bark exhibited good thermal stability, with a moisture-related mass loss of 11.10%. The adsorbent demonstrated excellent reusability, maintaining an adsorption efficiency above 84% after multiple cycles. Furthermore, the adsorption isotherms indicated that the process followed the Langmuir model, with a theoretical maximum adsorption capacity of 153.84 mg/g. These findings suggest that pine bark is a promising adsorbent for industrial wastewater treatment applications.

Currently, there is a global interest in the production of marine natural products. Naturally occurring macroalgae can be a potentially viable source of generating various products such as dyes and carbohydrates. Hence, in this study, the potential of extracting natural solvent-based dyes of Sargassum sp., Gracilaria sp., and Enteromorpha sp. was evaluated using the microwave-assisted extraction technique by applying the response surface methodology. In comparison with the conventional solvent extraction method, the microwave-assisted method enhanced the dye extraction by 70.37%, 64.31%, and 20.71% in Sargassum sp., Gracilaria sp., and Enteromorpha sp, respectively. Based on the results, increasing temperature, extraction time, and ethanol/water solvent ratio increased the dye extraction yield significantly for the microwave-assisted technique. Moreover, the effect of pH on the dye extraction was species-specific. In the second step, characterization techniques were used to examine the concentration and the optical activity of the extracted dyes by employing the UV–vis spectrophotometer and the circular dichroism, which showed them as promising candidates for sensitizers in dye-sensitized solar cells. Finally, a comprehensive economic and profitability analysis was conducted for both extraction methods. The results showed that the return on investment (ROI) for the conventional and microwave-assisted extraction methods was more than 358% and 268% for a production capacity of 10000 L, which corresponded to the payback period (PBP) of less than 4 and 5 months, respectively. In addition, it was found that increasing the production capacity would significantly decrease the PBP and the total production cost (TPC) of both extraction methods. Estimated income and return cost (EIRC) for both processes also showed that the ROI for the microwave-assisted extraction method was less than the conventional solvent extraction method; however, the efficacy of the microwave-assisted extraction method was significantly higher than the conventional solvent method. By utilizing low-cost natural dyes, the production cost of DSSCs can be reduced, making them more competitive with conventional solar cell technologies.

Efficient adsorption of hydrocarbon and non-hydrocarbon gases is pivotal for air purification, gas separation, and emission control in industries such as petrochemicals, pharmaceuticals, and wastewater treatment. The presented experimental work investigates the adsorption capabilities of pomegranate peel for gas components in a controlled environment. Gas composition was measured before and after exposing the peel to the gas mixture, initially at a high flow rate, which was subsequently reduced to a very low flow rate. The results showcase notable gas composition changes, highlighting the peel’s efficacy as an adsorbent. Remarkably, the peel exhibited significant adsorption of heavier hydrocarbons, as evidenced by substantial decreases in the mole fractions of iC5, nC5, C6, and C7+ at both flow rates. Additionally, while nitrogen adsorption increased, carbon dioxide adsorption decreased, indicating a differential effect on different non-hydrocarbon gas components. These findings underscore the potential of pomegranate peel as a promising adsorbent for targeted gas components, with implications for industrial and environmental gas treatment processes.

The escalating energy crisis underscores the need for sustainable alternatives to traditional energy sources. Biogas, derived from the anaerobic digestion of organic waste, is emerging as a promising renewable energy source, with methane and carbon dioxide as its key constituents. Research on biogas conversion processes is crucial for the transformation of biogas, which includes biogas reforming techniques such as biogas steam reforming (BSR), sorption enhanced steam reforming (SESR), autothermal reforming (ATR), and dry reforming of biogas (DRB). These processes can convert biogas into valuable products such as hydrogen and methanol. This review critically evaluates the existing challenges and the potential development directions in the field possible through the adjustment of reaction conditions and innovative designs in the biogas conversion processes. Furthermore, it explores the potential of biogas in the production of various high-value chemicals, providing a comprehensive perspective on its applications in the energy and chemical industries.

This investigation discusses the extraction and characterization of banana fiber from pseudostems of the Nendran and Grand Naine banana variety, with a special focus on the latter’s potential to act as a sustainable reinforcement in green composites. The Nendran pseudostem fiber exhibited fine linear density with 14.50 tex, excellent breaking load with a value of 327.33 g, and tenacity of 22.92 g/tex. The result of chemical analysis of Nendran fibers is an amount of 59.22% cellulose, and it can also be used in high-performance applications. It shows the existence of cellulose, hemicellulose, and lignin due to the crystallinity index being 20.33%, which proves improved mechanical properties. A maximum degradation temperature at 370.94 °C has verified its thermal stability, which can also aptly suit applications that require heat resistance. This study’s philosophy is to encourage the utilization of banana fiber as a biodegradable reinforcement for replacing synthetic reinforcements of industries such as automotive, aerospace, and textiles.

This study investigates the potential of mung bean husk, an agricultural waste, as a precursor for producing activated carbon (ACzm) to remove Cr (VI) from water. ZnCl2 activation was employed to develop a mesoporous (2.30 nm) ACzm with a high surface area (1594.15 m²/g) and abundant functional groups. Batch adsorption experiments demonstrated efficient Cr (VI) removal (97.88%) under optimal conditions (pH 2, temperature 25 °C, and adsorbent dose 1 g/L). Langmuir isotherm and pseudo-second-order kinetic models accurately described the adsorption process. Thermodynamic studies confirmed the spontaneous and exothermic nature of Cr (VI) adsorption. Moreover, the AC exhibited good reusability, maintaining 87.94% removal efficiency after five cycles. This research highlights the potential of agricultural waste–derived AC as a sustainable and cost-effective solution for Cr (VI) remediation.

The agricultural sector is challenging to decarbonise due to its reliance on heavy machinery and fossil fuels, which face issues when decarbonising via methods such as electrification. However, agriculture provides opportunities to generate renewable energy via biomass sources due to their abundance within this sector. This feasibility study used a continuous auger pyrolysis system to assess how straw waste from a medium-scale arable farm could convert energy from an external electrical source into usable chemical potential. Wheat, barley, oil seed rape (OSR), and bean straw have all been processed and pyrolysed under different temperatures and auger feed rates. The syngas product was then analysed, considering its composition and the lower heating value. Results indicate that the percentage of carbon monoxide and hydrogen and the total volume of syngas increased with temperature. In addition, the syngas’ energy quantity increased despite the product’s decreasing heating value. The case study’s annual energy demand was equal to 14.4% of the 3900 GJ maximum potential contained within the syngas, and thus it can be concluded that there is potential for the application of this system towards a circular economy. The system’s cold gas, net, and electrical conversion efficiency were also assessed with maximum values of 37.1%, 30.1%, and 174.4%, respectively. Furthermore, the statistical analysis confirms high predictability for wheat, barley, bean, and OSR feedstocks, with a general linear model showing high accuracy across all.

In this study, levulinic acid is produced from Jerusalem artichoke (JA, Helianthus tuberosus L.) by hydrothermal decomposition reactions in a batch autoclave reactor. The parameters studied were reaction temperature (T, K), reaction time (t, min), starting material concentration (C), and pH of the aqueous HCl solution (pHinitial) using the Box-Behnken response surface methodology. The highest yield was 35.28% at 165 °C, 89.7 min, 0.5 pH, and 0.045 g/mL concentration within a 95% confidence interval. Dilute feedstock concentrations, low pH of the aqueous acid catalyst solution, and relatively high temperatures should be preferred to maximize the yield LA. Graphical Abstract Figure graphical abstract 1. The result of the response optimizer for LA within the studied operating conditions Figure graphical abstract 1. Variation of organic acid and furfural content, in the liquid product over time at different reaction temperatures at 0.045 g/mL and pH = 1.0 Figure graphical abstract 2. Variation in the yields of organic acid and furfural and sugar compounds in the liquid product over time at different reaction temperatures at 0.045 g/mL and pH = 1.0

Glycerol-based biotechnological production of 1,3-propanediol (PDO) has taken center stage after its recent commercialization by Metabolic Explorer. The present study unveils the potential of a novel alkalophilic, BSL-1 bacterium Citrobacter freundii IIPDR3 to produce 1,3-PDO from glycerol. The culture conditions were optimized at shake flask level using one-variable-at-a-time (OVAT) approach, and statistically significant parameters were identified. The optimal conditions for batch production of 1,3-PDO were phosphate-buffered glycerol-based medium essentially containing 1.5 gL⁻¹ ammonium sulfate, 3 gL⁻¹ yeast extract, and 0.5 gL⁻¹ magnesium sulphate, temperature 36 °C, pH–stat of 8.0, and inoculum size being ≥ 35 µgbacterial cells/mL on dry cell weight (DCW) basis. Incorporation of 0.2% Tween 80 in the fermentation medium improved glycerol uptake rate and prevented self-flocculation of bacterial cells. Using liquor NH3 as a neutralizing agent, C. freundii IIPDR3 produced a maximum of 18.04 ± 0.76 gL⁻¹ 1,3-PDO from pure glycerol, with productivity and yield being 1.72 gL⁻¹ h⁻¹ and 0.53 gg⁻¹, respectively. When the robustness of the strain was tested on crude glycerol (CG), it accumulated 9.65 and 11.11gL⁻¹ 1,3-PDO in 7 h and 10.5 h with initial glycerol concentrations of 20 and 40 gL⁻¹, respectively. The study confirms that C. freundii IIPDR3 can be a promising candidate to tackle CG, a prominent waste derived from biodiesel industry, and simultaneously upgrade it to valorized products such as 1,3-PDO.

The purpose of the current study was to assess the sorptive properties of casuarina seed powder (CSP) to get rid of the dye rhodamine B (RhB). Activators’ roles (acid and alkali) in modification of the sorbent characteristics were studied. CSP and activated CSP features were analyzed by the textural characteristic study, scanning electron microscope (SEM) analysis, FTIR (Fourier-transform infrared (FTIR) spectroscopy) spectrum study, elemental composition and thermal degradation study. Thermodynamic studies were performed and ΔG°, ΔH° and ΔS° were calculated. Batch adsorption studies were done to examine the effect of solution pH (4–12), temperature (25 to 45 °C), dosage (0.1 to 1.2 g/L) and dye concentration (50 to 200 mg/L) on removal of RhB. The findings indicate that alkali-treated CSP biomass achieves a maximum removal efficiency of 98.05% at an initial concentration of 200 mg/L, a temperature of 35 °C, a pH of 7 and a sorbent dosage of 0.6 g/L for the alkali-treated CSP. Langmuir isotherm shows good regression with a maximum uptake of 28.5, 25.8 and 32.57 mg/g using raw CSP, acid-treated CSP and alkali-treated CSP, respectively. The experimental data fits well with the pseudo-second-order model equation and was better governed. The adsorption is found to be endothermic and spontaneous at high temperature. The results suggest that modified CSP can be a suitable candidate for the removal of dyes.

This study explores the use of wolf fruit peel as a sustainable source for producing cellulose nanofibers (CNFs). By valorizing this agricultural byproduct, the research contributes to the circular economy and reduces environmental impact, offering a high-value material with potential for composite reinforcement. The chemical treatment effectively purified cellulose by removing amorphous compounds, yielding nanometer-scale cellulose fibers. Acid hydrolysis using different concentrations of H2SO4 (0.1, 1, and 10% v/v) was essential for CNF production, enabling efficient isolation. Approximately 50% of hemicellulose and lignin were removed, as confirmed by FTIR analysis. However, higher H2SO4 concentrations (≥ 1%) damaged cellulose crystals by attacking both amorphous and crystalline regions, reducing the crystallinity index. CNFs obtained with lower H2SO4 concentrations exhibited enhanced stability, reduced aggregation, and thermal stability around 145 ºC, indicating their suitability for biopolymer reinforcement. This study introduces an innovative and sustainable approach to utilizing local biomass for developing new materials.

Searching for renewable raw materials that would comply with the requirements of Green Chemistry and the assumptions of sustainable development is an ongoing and important problem. In the present article, an attempt was made to obtain biopolyols from selected solid plant fats, i.e., babassu, cocoa, coconut, mango, palm, or shea oil. In the research performed, modification of plant oil was provided by a one-step and solvent-free transesterification method, to obtain biopolyols characterized by hydroxyl numbers from 360 to 460 mgKOH/g. Biopolyols from plant oils were subsequently used to obtain polyurethane viscoelastic foams (PUVFs). Biopolyols were applied in the amount of 10%, 20%, and 30% relative to the total weight of the polyols used to prepare PUVFs. The obtained materials were characterized by an apparent density of about 100 kg/m³, a hardness of about 2–3 kPa, a comfort factor of about 2.5, and a resilience of less than 10%, which may be interesting to the industrial sector for applications such foams as the materials able to energy absorbing. The study analyzed the effect of the chemical structure of the oils on the physicochemical properties of the obtained biopolyols, as well as the physical and mechanical properties of PUVFs.

Use of wood pellets is continuously increasing in Europe, and most of them carry the ENplus A1 label. In this research, 28 assortments of such A1-labeled wood pellets were collected from the fuel market and were comprehensively analyzed and combusted in two residential pellet stoves; up to 8 pellet assortments were also combusted in two residential pellet boilers. Correlation analyses have been carried out, including the results from 31 additional pellet assortments from an own pelleting process where specifically tailored pellet characteristics were produced using different wood species. In particular, the effects of pellet length, moisture content, fines content, raw material preparation, additives, and wood species were investigated to identify the dependencies between the investigated fuel parameters and pollutant emissions. The most important parameters influencing pollutant emissions especially from domestic pellet stoves were identified as the potassium content of the fuel, the hardwood content, the carbonate content of the fuel ash, the Si/K molar ratio, and the energy density. Total particulate matter (TPM) emissions ranged from 45 to 246 mg/m³ for pellet stove 1, whereas for pellet stove 2, TPM emissions from 23 to 58 mg/m³ have been observed. Not the same pellets performed best or worst in both pellet stoves. Overall, the current state of the art stoves showed a greater response to variations in pellet quality compared with boilers, and improvements in pellet stove technology and control are recommended.

In the present work, we prepared a novel efficient and environment-friendly poly (acrylonitrile)-grafted-cellulosic biosorbent from wheat straw. Poly (acrylonitrile) chains were grafted onto the cellulosic backbone and biosorbent cellulose-g-acrylonitrile (Cell-g-AN) was used for the removal of organic pollutants such as methyl red (MR), rhodamine 6G (Rh 6G) and methylene blue (MB) dyes from polluted water. Batch adsorption experiments were done to improve operating parameters. We examined the relationship between dye adsorption and pH, temperature, and contact time. The Cell-g-AN’s high grafting percentage value and nitrile group of AN, which under ideal pH conditions give extra binding sites, were found to be related to the material's adsorption capability for a variety of dyes. Under optimized circumstances, cellulose demonstrated maximal dye-removing capacities of 87.64%, 88.49%, and 63.08% for Rh 6G, MB, and MR dyes, respectively. Contrarily, Cell-g-AN showed 92.66%, 97.10%, and 66.86% for MB, Rh 6G, and MR dyes, respectively. Higher correlation coefficient results showed that Temkin and Langmuir adsorption models are most suitable for dyes, whereas when examining the adsorption kinetics of dye sorption, the pseudo 2nd order kinetic model fits better. Graphical Abstract

Oil palm frond (OPF) is an underutilized biomass that can be a feedstock for producing activated carbon (OPFAC) for Remazol Brilliant Orange 3R (RBO3R) removal. In this study, phosphoric acid (H3PO4) was used as a chemical activator, and microwave irradiation was used as rapid heating source for preparing OPFAC that possesses large surface area with high porosity for a high sorption capacity. The physicochemical properties of the OPFAC were characterized by Fourier-transform infrared spectroscopy (FTIR), BET surface area, and pHpzc. The specific surface area of OPFAC (376.4 m²/g) indicates production of mesoporous activated carbon with a pHpzc of 5.06. Optimized adsorption parameters are 0.06 g OPFAC, 50 mg/L initial RBO3R dye concentration at pH 2 for 60 min. Batch sorption study has found that the adsorption of RBO3R molecule onto OPFAC surface is following the Langmuir isotherm model with maximum sorption capacity of 155.1 mg/g. The pseudo-first-order (PFO) model is the best fit for the kinetic study, as it has a lower root mean square deviation (RMSD) value of 2.13 compared to the pseudo-second-order (PSO) model, which has an RMSD value of 6.50. This lower RMSD indicates that the PFO model’s calculated qe values align more closely with the experimentally determined qe values across all concentrations. Adsorption thermodynamic study showed the endothermic property of the sorption performance by the positive ΔHo value and the increase in temperature will promote the RBO3R removal.

Hitherto, a simple and sustainable two-step process has been explored and provided to convert uneconomical biomass into highly valuable furfural. Herein, through the enzymatic hydrolysis and the cellulose-functionalized phosphotungstic acid hydrothermal method, a carbon-based catalyst was synthesized from bagasse-derived cellulose (H-C@PWO3). Besides, the catalyst was then characterized using modern analytical techniques. SEM images of the H-C@PWO3 reveal the fibrous structure of cellulose is retained after the hydrothermal process with the phosphotungstic acid agent. The catalytic capacity of the H-C@PWO3 material was evaluated through the conversion of bagasse-based xylose to furfural. The highest furfural yield of 80.08% was achieved at 180 °C for 60 min, with a xylose concentration of 3 g/L of xylose, 50.00 mg of H-C@PWO3 catalyst, and 0.005 M HCl concentration. This attempt demonstrates the synergies of H-C@PWO3 acting as Lewis acid sites and HCl acting as Brønsted acid sites, promoting furfural production. Simultaneously, the reusability of the H-C@PWO3 material was investigated over several cycles. Furthermore, this study offers a new, alternative, and renewable approach to recycling agro-industrial by-products, especially bagasse. Graphical abstract

The application of biochar, a thermochemically converted blackish biomass, is considered an economical and efficient strategy for the remediation of nickel (Ni²⁺) and manganese (Mn²⁺) ions from watery matrix to mitigate environmental contamination and safeguard public health. A wide variety of techniques, ranging from laboratory to industrial scale, have been developed to produce biochar. However, in rural areas of developing countries, biomass is typically used for cooking without being charred. The strategies for producing biochar on a small scale for farmers have not advanced significantly. In this current study, a scraped 200-L oil drum is modified to fabricate a drum kiln setup for producing biochar from areca nut husk (AH), a locally available agro-residue of Northeast India. The prepared areca nut husk biochar (AHB) was further evaluated for adsorptive removal of Ni²⁺ and Mn²⁺ from water. AHB reaches the equilibrium time at 150 min and 180 min for Ni²⁺ and Mn²⁺, respectively. The experimental data has shown a good fit for the pseudo-second-order kinetic model and Freundlich isotherm model for both metals, revealing a chemisorption-driven monolayer adsorption mechanism. The presence of oxygen-containing functional groups on the AHB surface required for chemisorption was confirmed by different spectroscopy methods. AHB could be regarded as an effective adsorbent for the rapid elimination of heavy metals from water, and the biochar production strategy using a drum kiln has been demonstrated to be the simplest and most effective method for achieving self-sustainability.

Lignocellulose biomass (LCB) gasification presents considerable opportunities for environmental conservation, energy crisis mitigation, and the advancement of the circular economy; nonetheless, its entire realisation is hindered by multiple obstacles. Comprehensive evaluation of different challenges is vital for enhancing the use of bioenergy. The study has identified sixteen obstacles and the analytical hierarchy process (AHP), frequently utilized in multiple criteria decision-making (MCDM), is applied to rank the obstacles that hinder the successful execution of LCB gasification. AHP is acknowledged for its ability to decompose multifaceted problems into an apparent hierarchical framework. The AHP theory is based on three core principles: decomposition, comparative evaluation and synthesis. The result of the study reveals that operational challenges are the most significant obstacle, weighing 0.1257, followed by gas cleaning at 0.1107, and the consolidation of initial funds, market establishment and harvesting and collection at 0.1037, 0.0913 and 0.0749, respectively. A strategic approach to LCB gasification advancement can foster global community well-being, drive economic development and improve energy access. This study seeks to provide a solution for researchers and stakeholders addressing energy scarcity and the challenges related to biomass gasification.

Aloe vera gel is widely used in cosmetics due to its biological activities, but its extraction leads to high waste generation. Therefore, developing alternatives that can convert Aloe vera residues into value-added products is attractive. The present study proposes obtaining bioactive phenolic compounds and ethanol from the fractionation of the residue, including solid–liquid extraction, alkaline pretreatment, and extraction in aqueous two-phase systems (ATPSs). The solid–liquid extraction with ethanol was effective, recovering 26.99 mg of phenolic compounds per gram of material. In the ATPS extraction, the composition of the ethanol/ammonium sulfate system and the pH showed sensitive effects on the yield of phenolic compounds in the top phase, which presented a level of 90%. To improve productivity, the 20% ethanol/22% ammonium sulfate/40% extract condition without pH adjustment was selected, and it was able to achieve 93.5% yield and a partition coefficient of 14.2. In addition to ensuring the isolation of phenolics, the top phase of ATPS showed high DPPH (4710.53 mmol TE/mL) and ABTS (2217.50 mmolTE/mL) radical scavenging capacity, similar to the results of the initial extract. The post-extraction residue was used as raw material for alkaline pretreatment, and the pretreated residue showed higher enzymatic digestibility than the untreated residue. Under 10% solids loading and 20 FPU/g cellulases, 30.31 g/L glucose and 75.45% cellulosic conversion were obtained from the hydrolysis of the alkaline-pretreated residue. Ethanol production via simultaneous saccharification and fermentation increased as a function of the solid loading and reached its maximum value of 21.74 g/L at 15% solids (yield of 70.93%). Therefore, this study acts on the circular economy of Aloe vera and can contribute to efforts to increase the value of the plant.

Paramylon is a crystalline β-1,3-glucan polysaccharide polymer with medicinal value and the main storage molecule of Euglena gracilis. Paramylon is usually insoluble in water and alcohol, and soluble in alkali. Most of the earlier extraction methods are limited by low solubility in water and alcohol, often requiring harsh solvents. Present study presented a novel, green extraction technique using a deep eutectic solvent (DES) synthesized from choline chloride (ChCl) and monoethanolamine (MEA) for efficient paramylon extraction. Based on results of single factor experiments assessed the influence of the time required for extraction (20–80 min), extraction temperature (30–90 °C), and DES-biomass ratio (2.5–12.5 mg/mL) on the yield of paramylon, leading to a Box-Behnken central combination experiment at optimized extraction conditions. Based on the experimental results, the optimized extraction conditions were selected as an extraction time of 48 min, a temperature of 58 ℃, and a DES-biomass ratio of 4.70∶1 (mg/mL). Under these conditions, the yield of paramylon was 39.47% based on dry biomass weight. The recovery and reuse performance of DES demonstrated satisfactory performance up to four reuse cycles, indicating its suitability for sustainable extraction. The property analysis confirmed that the DES-extracted paramylon meets the analytical standard and is suitable for application in food or feed items. This study presents a green, sustainable, and scalable extraction method from algal biomass that aligns with environmentally friendly principles.

In this paper, Pergularia tomentosa pods were used a starting abundant material for the preparation of biochar through pyrolysis process. The prepared Pergularia biochar was, then, functionalized with poly (diallyldimethylammonium chloride) at different ratios (3%, 5%, and 10% v/v) and, further, applied for the adsorption of two anionic dyes: Acid Blue 25 and Acid Red 18. The aminated Pergularia biochar was characterized by BET, FT-IR, XRD, SEM, and TGA/DTG analyses. The specific surface area decreased from 58.4 m²/g for unmodified biochar to 9.5 m²/g for Pergularia biochar-poly(diallyldimethylammonium chloride) (10%). The most intense peak in XRD patterns, observed at 2θ = 29.5, confirmed the turbostratic structure of the graphite carbon. Thermogravimetric results revealed that the surface functionalization of Pergularia biochar with poly (diallyldimethylammonium chloride) significantly increased the weight loss of the biochar. The highest adsorption capacities achieved using Pergularia biochar-poly(diallyldimethylammonium chloride) (5%) were equal to 248 mg/g and 202 mg/g for Acid Blue 25 and Acid Red 18, respectively. The adsorption data were well fitted to both Langmuir and Temkin models. The thermodynamic parameters illustrated that the adsorption of Acid Blue 25 and Acid Red 18 on Pergularia biochar-poly(diallyldimethylammonium chloride) was exothermic and non-spontaneous. Adsorption results confirmed that Pergularia biochar-poly(diallyldimethylammonium chloride) could be considered as an outstanding material for the adsorption of anionic species from water.

The primary objective of this research is to develop chitosan (CS) membranes incorporated with Andrographis paniculata leaf extract (APLE) at varying concentrations (1, 2, and 3 wt% of chitosan). The study investigates the influence of APLE incorporation on the optical, physicomechanical properties, moisture content, water solubility, swelling percentage, and water vapor transmission rate of the membranes. Advanced analytical techniques were employed to confirm the successful integration of APLE into the CS matrix. The antimicrobial efficacy of the membranes was evaluated using the agar diffusion method against Staphylococcus aureus and Pseudomonas aeruginosa, revealing enhanced antimicrobial activity with the addition of APLE to the CS membranes. Furthermore, the anti-inflammatory potential of the synthesized membranes was assessed by their ability to prevent the denaturation of egg albumin. In an applied context, bananas coated with CS membranes containing 1 wt% APLE demonstrated extended shelf life compared to both control samples and those coated with pure CS membranes. These findings highlight the potential application of biologically derived CS-APLE membranes as an alternative to petroleum-based plastic packaging. Consequently, this study presents a safe and sustainable solution to mitigate the issue of non-biodegradable plastic, emphasizing its potential for packaging and food preservation applications. Graphical abstract