Search Results (126)

Power-to-X technologies play a crucial role in accelerating the energy and material transition. A key opportunity lies in integrating these systems with existing bio-based infrastructures such as anaerobic digesters, providing a reliable source of biogenic carbon. Developing effective Power-to-Methanol (PtM) pathways requires a comprehensive understanding of process behavior through detailed simulation, including technical performance, economic feasibility, and environmental consequences. Despite growing interest, substantial variation remains in published levelized methanol costs, and many assessments insufficiently account for the full environmental footprint of production routes. This study evaluates the potential of PtM deployment in the Netherlands by comparing two pathways that utilize biogenic carbon sources: (i) hydrogenation of captured CO₂ using green hydrogen and (ii) dry methane reforming (DMR) of biogas, followed by catalytic syngas conversion to methanol. Results indicate that operational expenses—mainly driven by renewable electricity consumption—far outweigh capital investment. Both routes yield an LCoMeOH of approximately €2630 per tonne, about five times the cost of fossil-based methanol. Life cycle analysis shows that DMR performs more favorably overall, although elevated freshwater ecotoxicity and eutrophication result from digestate application as fertilizer. Continued improvements in renewable energy integration and nutrient recovery technologies are essential for enhancing future economic and environmental performance. Full article

The increasing environmental pollution with persistent organic compounds demands the development of sustainable materials capable, among others, of simultaneous adsorption and catalytic degradation of pollutants. In this study, nickel-modified biocarbons were obtained in the process of biomass pyrolysis at the temperatures of 500 and 800 °C, with the Ni content of 5 and 10% by weight, in order to determine the effect of synthesis conditions on the structure, surface chemistry and functional properties of materials. A wide range of research methods was used to analyze structural parameters, elemental composition, surface morphology, functional groups as well as adsorption and photocatalytic properties. The results indicate that the pyrolysis temperature is the main factor determining the evolution of biocarbons, leading to a decrease in the specific surface area and microporosity, an increase in carbon aromatization, a reduction in oxygen groups, and an increase in alkalinity and thermal stability. The addition of nickel promotes formation of crystalline Ni phases and redox centers, while partially blocking micropores. As a result, the materials obtained at 800 °C are characterized by an increased photocatalytic activity. The paper provides mechanistic insights into the structure–property–function relationships and practical guidance for the design of biocarbons with optimized adsorption and photocatalytic properties. Full article

In this study, biocarbon adsorbents were obtained from fennel and caraway seeds through microwave-assisted chemical activation with sodium carbonate. The activation process involved carbonizing the raw material at 300 °C for 30 min., followed by impregnation with sodium carbonate at a precursor-to-activator mass ratio of 1:2. Activation was performed at two distinct temperatures—500 °C and 600 °C—with an activation time of 15 min. The structural, textural, and surface chemical characteristics of the obtained biocarbons were investigated using complementary analytical techniques, including low-temperature nitrogen adsorption–desorption isotherms, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Boehm titration, and pH analysis of aqueous extracts. The resulting adsorbents demonstrated low development of specific surface area (109–154 m²/g) and limited sorption capacity for methylene blue (20–32 mg/g). Adsorption experiments indicated that the Freundlich isotherm model most accurately described the data, suggesting multilayer adsorption on heterogeneous surfaces. Thermodynamic evaluations showed the adsorption to be both spontaneous and endothermic. The adsorption mechanism is primarily governed by electrostatic interactions between the cationic dye and surface functional groups, π–π interactions with the carbon structure, and diffusion within mesopores. This study provides a comparative evaluation of microwave-assisted Na₂CO₃ activation of fennel and caraway seed waste and assesses the potential of these biochars for dye removal from aqueous solutions. Full article

The main objective of the work was to prepare a series of new activated biocarbons by chemical activation of black chokeberry seed and to assess their suitability for removing cationic and anionic dyes from an aqueous medium. Activation of the precursor was performed at 550 °C with orthophosphoric acid, using conventional or microwave-assisted heating. The activated biocarbons were characterized in terms of elemental composition, textural parameters, surface morphology, acid-base character of the surface, as well as electrokinetic properties. Adsorption tests were carried out against two organic compounds: methylene blue (thiazine dye of cationic character) and Congo red (azo dye of anionic character). The influence of the initial dye concentration (5–120 mg/L), temperature (20–40 °C), and solution pH (2–10) on dye removal efficiency from the liquid phase was investigated. Additionally, kinetic adsorption tests were carried out to determine the rate and mechanism of the dyes removal process. Microwave-assisted chemical activation with H₃PO₄ proved to be a very effective approach for generating a high specific surface area (884 m²/g) and a micro/mesoporous structure, which directly increases the adsorption capacity of activated biocarbons towards cationic and anionic synthetic dyes. The maximum adsorption capacities for methylene blue and Congo red were 194.5 and 68.6 mg/g, respectively. It was also confirmed that the choice of heating method at the activation stage plays a key role in determining the physicochemical properties and adsorption performance of the activated biocarbons prepared from waste biomass. In general, carbonaceous adsorbents derived from black chokeberry seeds exhibit high potential for the treatment of dye-contaminated wastewater. Full article

The escalating release of synthetic dyes from textile and allied industries has become a pressing global environmental issue due to their toxicity, persistence, and resistance to biodegradation. Among the various treatment strategies, adsorption has emerged as one of the most efficient, economical, and sustainable techniques for dye removal from aqueous environments. This review highlights recent advances in bio-derived adsorbents—particularly raw biomass powders, biochars, and activated carbons—developed from renewable waste sources such as agricultural residues, fruit peels, shells, and plant fibers. It systematically discusses adsorption mechanisms, the influence of process parameters, kinetic and thermodynamic models, and regeneration performance. Furthermore, the review emphasizes the superior adsorption efficiency and cost-effectiveness of biomass-derived carbons compared to conventional adsorbents. The integration of surface modification, magnetization, and nanocomposite formation has further enhanced dye uptake and reusability. Overall, this study underscores the potential of biomass-derived materials as sustainable alternatives for wastewater treatment and environmental remediation. Full article

This study demonstrates the complete transformation of almond shell waste into a high-performance carbon material for carbon paste electrode (CPE) fabrication. The biocarbon was synthesized via carbonization at 800 °C and subsequently activated with CO₂, resulting in a semicrystalline structure rich in carbonyl groups—consistent with its lignocellulosic origin (34.25% cellulose, 13.48% hemicellulose, 48.03% lignin). Carbonization increased the total pore volume of carbonized almond (CAR_ALD) by nearly 13-fold and the specific surface area by over two orders of magnitude compared to raw almond (RAW_ALD), while CO₂ activation further enhanced activated almond’s (ACT_ALD) surface area (~19%) and pore volume (~35%). To improve electrochemical performance, Bi₂O₃ doped with Sm was applied as a surface modifier. Comprehensive characterization (N₂ physisorption X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopic Analysis (FTIR), X-Ray Photoelectron Spectroscopic Analysis (XPS), Thermogravimetric and Differential Thermal Analysis (TG-DTA), Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS)) confirmed the material’s structural integrity, graphitic features, and successful modifier incorporation. Electrochemical testing revealed the highest current response (48 µA) for the CPE fabricated from CAR_ALD/Bi₂O₃-Sm, indicating superior electrocatalytic activity and reduced charge transfer resistance. Notably, this is the first report of a fully functional CPE working electrode fabricated entirely from waste material. Full article

Activated biocarbons were synthesized from avocado seeds using potassium carbonate as an activating agent. The study aimed to evaluate K₂CO₃ as a greener and less corrosive alternative to KOH, traditionally used for producing porous carbons. Twelve samples were obtained under varying activation conditions using both dry K₂CO₃ and its saturated solution. The material activated at 800 °C with a 1:1 precursor-to-activator ratio (C_K₂CO₃_800) showed the highest CO₂ adsorption capacity of 6.26 mmol/g at 0 °C and 1 bar. Nitrogen adsorption–desorption analysis confirmed a predominantly microporous structure, with ultramicropores (0.3–0.7 nm) primarily responsible for the high CO₂ uptake. The Sips model provided the best fit to the adsorption equilibrium data, indicating a heterogeneous surface. The isosteric heat of adsorption (22–26 kJ/mol) confirmed a physical adsorption mechanism. Furthermore, the CO₂/N₂ selectivity, evaluated using the Ideal Adsorbed Solution Theory (IAST), reached values up to 18 at low pressures, highlighting the excellent separation performance. These findings demonstrate that avocado seed-derived activated carbons prepared with K₂CO₃ are efficient, renewable, and environmentally friendly sorbents for CO₂ capture, combining high adsorption capacity with sustainability and ease of synthesis. Full article

This study investigates the efficiency of biocarbon derived from Prosopis juliflora shells in removing Astrazon pink dye from aqueous solutions. The biocarbon obtained from the thermochemical process was characterised using FTIR Spectroscopy, SEM microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS), and XRD. Batch adsorption experiments were conducted to assess various factors, including the Potential of Hydrogen (pH), Dosage of biocarbon, Astrazon pink dye concentration, temperature, and Time of contact. Similarly, Adsorption isotherm models, including the Langmuir and the Freundlich isotherms, were used to evaluate the adsorption capacity. In contrast, pseudo-first-order and pseudo-second-order models were used to analyse the kinetics of dye adsorption. The interactive effects of selected variables on the removal of Astrazon Pink dye from synthetic water were determined using Response Surface Methodology (RSM). The maximum dye uptake, 98.54%, was achieved with a biochar dose of 8 g/L at 50 ppm dye concentration, pH 7.5, and 35 °C. The Freundlich adsorption isotherm model and the pseudo-second-order kinetic model are the better-fitting models for the dye adsorption process, with R² values of 0.99. Consequently, the thermodynamic parameters indicate that the process is endothermic and spontaneous. Full article

Extraction processes of alginates from Sargassum spp. generate a substantial number of solid residues that are commonly discarded. This study explores the sustainable transformation of these residues into nitrogen-doped biocarbon through chemical activation with KOH and nitrogen doping using urea. XRD, FTIR, SEM-EDX, Raman spectroscopy, BET surface area analysis, XPS, and CHNS elemental analysis were used to characterize the materials. The doped and activated biocarbon (BDA) demonstrated excellent physicochemical properties, including a specific surface area of 1790 m² g⁻¹ and a mesoporous structure. Electrochemical evaluation in alkaline media revealed a current density of −4.37 mA cm⁻², an onset potential of 0.922 E vs. RHE, and a half-wave potential of 0.775 E vs. RHE. Koutecky–Levich analysis indicated a two-electron reduction pathway. The superior performance was attributed to the synergistic effects of high surface area, nitrogen functionalities (pyridinic-N and pyrrolic-N), and enhanced accessibility of active sites. These results highlight the potential of waste-derived, nitrogen-doped biocarbon as a sustainable and low-cost alternative for ORR electrocatalysis in alkaline fuel cells. Full article

The application of biochar and beneficial microorganisms has gained attention as a sustainable strategy to enhance soil health and plant resistance to pathogens. Trichoderma spp. play critical roles in nutrient mobilization, rhizosphere colonization, and suppression of soilborne diseases. However, little is known about the interactive effects of biochar and Trichoderma on the suppression of Fusarium equiseti (P1I3)-induced root rot in grapevine seedlings. In this study, we investigated the effects of two Trichoderma aureoviride strains (URM 6668 and URM 3734), with and without grapevine pruning-derived biochar (BVP), on disease severity, plant growth, and soil properties. Our results revealed that the combination of biochar and Trichoderma significantly reduced disease incidence and promoted biomass accumulation. Notably, BVP and T. aureoviride URM 3734 were the most effective at reducing leaf disease severity, resulting in a 53% decrease. Conversely, the combination of BVP and T. aureoviride URM 6668 led to the greatest reduction in root disease severity, with a 56% decrease. These findings suggest a synergistic relationship between biochar and beneficial fungi, reinforcing the role of organic soil amendments in promoting plant health. The integrated use of biochar and Trichoderma strains offers a viable, environmentally sound approach for managing grapevine root rot and enhancing seedling health in sustainable viticulture systems. Full article

Oil palm kernel shell is an abundant agricultural waste generated by the palm oil industry. To achieve sustainable use of this waste, oil palm kernel shells were converted into valuable resources as active biocarbons. A two-stage preparation method involving N₂ pyrolysis, followed by CO₂ activation, was used to produce the active biocarbon. The optimum pyrolysis conditions that produced the largest BET surface area of 519.1 m²/g were a temperature of 600 °C, a hold time of 2 h, a nitrogen flow rate of 150 cm³/min, and a heating rate of 10 °C/min. The optimum activation conditions to prepare the active biocarbon with the largest micropore surface area or the best micropore/BET surface area combination were a temperature of 950 °C, a CO₂ flow rate of 300 cm³/min, a heating rate of 10 °C/min, and a hold time of 3 h, yielding BET and micropore surface areas of 1232.3 and 941.0 m²/g, respectively, and consisting of 76.36% of micropores for the experimental optimisation technique adopted here. This study underscores the importance of optimising both the pyrolysis and activation conditions to produce an active biocarbon with a maximum micropore surface area for gaseous adsorption applications, especially to capture CO₂ greenhouse gas, to mitigate global warming and climate change. Such a comprehensive and detailed study on the conversion of oil palm kernel shell into active biocarbon is lacking in the open literature. The research results provide a practical blueprint on the process parameters and technical know-how for the industrial production of highly microporous active biocarbons prepared from oil palm kernel shells. Full article

The oxygen evolution reaction (OER) plays a central role as an anode in electrocatalytic processes such as energy conversion and storage and the generation of molecular oxygen from the electrolysis of water. Currently, precious metal oxides such as IrO₂ and RuO₂ are recognized as reference OER electrocatalysts with reasonably high activity; however, their widespread use in practical devices has been severely hindered by their high cost and scarcity. It is essential to design alternative OER electrocatalysts made of low-cost and abundant earth elements with significant activity and robustness. We report four new nanocellulose-derived Fe–zeolite nanocomposites, namely Fe/Zeolite@CCNC (1), Fe/Zeolite@CCNF (2), Fe/Zeolite/CNT@CCNC (3), and Fe/Zeolite/CNT@CCNF (4). Two different types of nanocellulose were investigated: nanocellulose nanofibrils and nanocellulose nanocrystals. Characterization with TEM, SEM-EDS, PXRD, and XPS is reported. The nanocomposites exhibited electrocatalytic activity for OER that varies based on the origin of biocarbon and the composition content. The effect of adding carbon nanotubes to the nanocomposites was studied, and an improvement in OER catalysis was observed. The electrochemical double-layer capacitance and electrochemical impedance spectroscopy of the nanocomposites are reported. The nanocomposite 3 exhibited the highest performance, with an onset potential value of 1.654 V and an overpotential of 551 mV, which exceeds the activity of RuO₂ for OER catalysis at 10 mA/cm² in the glassy carbon electrode. A 24 h chronoamperometry study revealed that the catalyst is active for ~2 h under continuous operating conditions. BET surface analysis showed that the crystalline nanocellulose-derived composite exhibited 301.47 m²/g, and the fibril nanocellulose-derived composite exhibited 120.39 m²/g, indicating that the increased nanoporosity of the former contributes to the increase in OER catalysis. Full article

In the energy sector and in other types of industries (cement, iron/steel, chemical and petrochemical), highly roasted coffee ground residue can be used as a source material for producing bioadsorbents suitable for CO₂ capture. In this study, a bioadsorbent was produced in a two-step process involving biowaste carbonization and biocarbon activation within a KOH solution. The physicochemical properties of the bioadsorbent were assessed using LECO, TG, SEM, BET and FT-IR methods. Investigating the CO₂, O₂ and N₂ equilibrium adsorption capacity using an IGA analyzer allowed us to calculate CO₂ selectivity factors. We assessed the influence of exhaust gas carbon dioxide concentration (16%, 30%, 81.5% and 100% vol.) and adsorption step temperature (25 °C, 50 °C and 75 °C) on the CO₂ adsorption capacity of the bioadsorbent. We also investigated its stability and regenerability in multi-step adsorption–desorption using a TG-Vacuum system, simulating the VSA process and applying different pressures in the regeneration step (30, 60 and 100 mbar_abs). The tests conducted assessed the possibility of using a produced bioadsorbent for capturing CO₂ using the VSA technique. Full article

This study presents research on the production of activated biocarbons derived from herbal waste. Sage stems were chemically activated with two activating agents of different chemical natures—H₃PO₄ and K₂CO₃—and subjected to two thermal treatment methods: conventional and microwave heating. The effect of the activating agent type and heating method on the basic physicochemical properties of the resulting activated biocarbons was investigated. These properties included surface morphology, elemental composition, ash content, pH of aqueous extracts, the content and nature of surface functional groups, points of zero charge, and isoelectric points, as well as the type of porous structure formed. In addition, the potential of the prepared carbonaceous materials as adsorbents of model organic (represented by Triton X-100 and methylene blue) and inorganic (represented by iodine) pollutants was assessed. The influence of the initial adsorbate concentration (5–150 (dye) and 10–800 mg/dm³ (surfactant)), temperature (20–40 °C), and pH (2–10) of the system on the efficiency of contaminant removal from aqueous solutions was evaluated. The adsorption kinetics were also investigated to better understand the rate and mechanism of contaminant uptake by the prepared activated biocarbons. The results showed that materials activated with orthophosphoric acid exhibited a significantly higher sorption capacity for all tested adsorbates compared to their potassium carbonate-activated counterparts. Microwave heating was found to be more effective in promoting the formation of a well-developed specific surface area (471–1151 m²/g) and porous structure (mean pore size 2.17–3.84 nm), which directly enhanced the sorption capacity of both organic and inorganic contaminants. The maximum adsorption capacities for iodine, methylene blue, and Triton X-100 reached the levels of 927.0, 298.4, and 644.3 mg/g, respectively, on the surface of the H₃PO₄-activated sample obtained by microwave heating. It was confirmed that the heating method used during the activation step plays a key role in determining the physicochemical properties and sorption efficiency of activated biocarbons. Full article

A copper nanoparticles@porous biocarbon substrate was designed for Surface-Enhanced Raman Spectroscopy (SERS) via a simple reduction method. In the detection of three trace antibiotics, the substrate exhibits a very high Raman enhancement efficiency. This is partly because the biocarbon is rich in meso-micropores, which can rapidly trap target molecules. On the other hand, the copper nanoparticles embedded on the surface of the carbon sheets generate a large number of plasmonic hotspots, leading to an increase in Raman signal intensity. These results suggest that this substrate has utility for SERS applications in food safety, medicine, and water pollution detection. Full article