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Lignocellulosic waste generation and their improper disposal has accelerated the problems associated with increased greenhouse gas emissions and associated environmental pollution. Constructive ways to manage and mitigate the pollution associated with lignocellulosic waste has propelled the research on biochar production using lignocellulose-based substrates. The sustainability of various biochar production technologies in employing lignocellulosic biomass as feedstock for biochar production not only aids in the lignocellulosic biomass valorization but also helps in carbon neutralization and carbon utilization. Functionalization of biochar through various physicochemical methods helps in improving their functional properties majorly by reducing the size of the biochar particles to nanoscale and modifying their surface properties. The usage of engineered biochar as nano adsorbents for environmental applications like dye absorption, removal of organic pollutants and endocrine disrupting compounds from wastewater has been the thrust areas of research in the past few decades. This review presents a comprehensive outlook on the up-to-date research findings related to the production and engineering of biochar from lignocellulosic biomass and their applications in environmental remediation especially with respect to wastewater treatment. Further a detailed discussion on various biochar activation methods and the future scope of biochar research is presented in this review work., Competing Interests: Declaration of competing interest It is declared that all the authors mutually agreeing to submit this manuscript to the journal. It is also declared that co-authors do not hold any conflict of interest that may affect the publication of this manuscript., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Stormwater pollution is a key factor contributing to water quality degradation, posing substantial environmental and human health risks. Although stormwater retention ponds, also referred to as wet ponds, are commonly implemented to alleviate stormwater challenges by reducing peak flow and removing suspended solids, their effectiveness in removing heavy metals and nutrients is limited. This study evaluated the performance of floating treatment platforms (FTPs) featuring vetiver grass (Chrysopogon zizanioides), a non-invasive, nutrient- and metal-accumulating perennial grass, in removing heavy metals (Cu, Pb, and Zn) and nutrients (P and N) in stormwater retention ponds. Furthermore, the potential for utilizing the spent vetiver biomass for generating biochar and bioethanol was investigated. The study was conducted in a greenhouse setup under simulated wet and dry weather conditions using pond water collected from a retention pond in Stafford Township, New Jersey, USA. Two FTPs with vetiver (vegetated FTPs) were compared with two FTPs without vetiver (non-vegetated FTPs), which served as controls. Results showed that the removal of heavy metals and nutrients by the FTPs with vetiver was significantly higher (p < 0.05) than the FTPs without vetiver. Notably, vetiver showed resilience to stormwater pollutants and hydroponic conditions, displaying no visible stress symptoms. The biochar and bioethanol generated from the spent vetiver exhibited desirable yield and quality, without raising concerns regarding pollutant leaching, indicated by very low TCLP and SPLP concentrations. This study provides compelling evidence that the implementation of vetiver-based FTPs offers a cost-effective and environment-friendly solution for mitigating stormwater pollution in retention ponds. Furthermore, the utilization of vetiver biomass for biofuel and biochar production supports clean production and fostering circular economy efforts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Large amount of wastes are burnt or left to decompose on site or at landfills where they cause air pollution and nutrient leaching to groundwater. Waste management strategies that return these food wastes to agricultural soils recover the carbon and nutrients that would otherwise have been lost, enrich soils and improve crop productivity. The incorporation of liming materials can neutralize the protons released, hence reducing soil acidity and its adverse impacts to the soil environment, food security, and human health. Biochar derived from organic residues is becoming a source of carbon input to soil and provides multifunctional values. Biochar can be alkaline in nature, with the level of alkalinity dependent upon the feedstock and processing conditions. This study conducted a characterization of biochar derived from the pyrolysis process of eggplant and Acacia nilotica bark at temperatures of 300 °C and 600 °C. An analysis was conducted on the biochar kinds to determine their pH, phosphorus (P), as well as other elemental composition. The proximate analysis was conducted by the ASTM standard 1762-84, while the surface morphological features were measured using a scanning electron microscope. The biochar derived from Acacia nilotica bark exhibited a greater yield and higher level of fixed carbon while possessing a lower content of ash and volatile components compared to biochar derived from eggplant. The eggplant biochar exhibits a higher liming ability at 600 °C compared to the acacia nilotica bark-derived biochar. The calcium carbonate equivalent, pH, potassium (K), and phosphorus (P) levels in eggplant biochars increased as the pyrolysis temperature increased. The results suggest that biochar derived from eggplant could be a beneficial resource for storing carbon in the soil, as well as for addressing soil acidity and enhancing nutrients availability, particularly potassium and phosphorus in acidic soils., (© 2024. The Author(s).)

The extensive use of pharmaceuticals has raised growing concerns regarding their presence in surface waters. High concentrations of sulfamethoxazole (SMX) and lincomycin (LIN), as commonly prescribed antibiotics, persist in various wastewaters and surface waters, posing risks to public health and the environment. Biochar derived from accessible biowaste, like activated sludge biomass, offers a sustainable and eco-friendly solution to mitigate antibiotic release into water systems. This study investigates the effectiveness of H 3 PO 4 -modified activated sludge-based biochar (PBC) synthesized through microwave (MW) heating for the adsorption of SMX and LIN antibiotics. The synthesis parameters of PBC were optimized using a central composite design considering MW power, time, and H 3 PO 4 concentration. Characterization results validate the efficacy of the synthesis process creating a specific surface area of 365 m 2 /g, and well-developed porosity with abundant oxygen-containing functional groups. Batch and dynamic adsorption experiments were piloted to assess the adsorption performance of PBC in single and binary antibiotic systems. Results show that PBC exhibits a higher affinity for SMX rather than LIN, with maximum adsorption capacities of 45.6 mg/g and 26.6 mg/g, respectively. Based on kinetic studies chemisorption is suggested as the primary mechanism for SMX and LIN removal. Equilibrium studies show a strong agreement with the Redlich-Peterson isotherm, suggesting a composite adsorption mechanism with a greater probability of multilayer adsorption for both antibiotics. Hydrogen bonding and π-π electron sharing are suggested as the prevailing adsorption mechanisms of SMX and LIN on the modified biochar. Furthermore, a dynamic adsorption system was replicated using a fixed bed column setup, demonstrating effective removal of SMX and LIN from pure water and real wastewater samples using PBC-loaded hydrogel beads (PBC-B). These findings serve as crucial support for upcoming studies concerning the realistic application of sludge-based biochar in the removal of antibiotics from water systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Sustainable activated carbon can be obtained from the pyrolysis/activation of biomass wastes coming from different origins. Carbon obtained in this way shows interesting properties, such as high surface area, electrical conductivity, thermal and chemical stability, and porosity. These characteristics among others, such as a tailored pore size distribution and the possibility of functionalization, lead to an increased use of activated carbons in catalysis. The use of activated carbons from biomass origins is a step forward in the development of more sustainable processes enhancing material recycling and reuse in the frame of a circular economy. In this article, a perspective of different heterogeneous catalysts based on sustainable activated carbon from biomass origins will be analyzed focusing on their properties and catalytic performance for determined energy-related applications. In this way, the article aims to give the reader a scope of the potential of these tailor-made sustainable materials as a support in heterogeneous catalysis and future developments needed to improve catalyst performance. The selected applications are those related with H 2 energy and the production of biomethane for energy through CO 2 methanation.

Biochar has shown a unique electrochemical property being involved in various redox reactions in soil and water. In this study, the electron donating capacities (EDCs) of biochar pyrolyzed at 200-800 °C from pine wood, barley grass and wheat straw were investigated by using the mediated electrochemical oxidation method. The EDC values for all biochar were in the range of 0.18-1.83 mmol e - (g biochar) -1 , showing the increase as the temperature increased from 200 °C to 400 °C, the decrease from 400 °C to 650 °C, and then increase from 650 °C until to 800 °C. At low and intermediate temperatures of 200-650 °C, the EDCs were mainly attributed to the phenolic hydroxyl groups, while the conjugated π-electron system associated with aromatic structure dominated the EDCs of biochar at the high temperatures of over 650 °C. The barley grass- and wheat straw-derived biochar had higher EDCs than the pine wood-derived biochar, resulting from the higher phenolic hydroxyl groups in the former samples than the latter one. In conclusion, the reductive property of biochar was mainly attributed to both phenolic hydroxy group and conjugated π-electron system associated with aromatic structure, depending on the pyrolytic temperature and feedstock source. The results will help us to obtain a complete view on the role of biochar in biogeochemical redox reactions and consider developing biochar with controlled redox properties for specific environmental applications such as electron shuttle and catalyst material., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In order to investigate contributions of cellulose (CEL), hemicellulose (HEM), lignin (LIG) to the sorption capacity of biochar derived from lignocellulose, the individual component and their artificially modeled biomass mixture (C-H-L) were pyrolyzed under oxygen-limited condition at various pyrolytic temperatures (i.e. 250, 350, 500, 700 °C). The characterization analysis of biochars and sorption batch experiments were carried out. Variations in physiochemical property of different component biochars resulted in discrepancies in their ability to function as sorbents to 1,2,4-trichlorobenzene (1,2,4-TCB). The maximum mass sorption capacity (Qfm) of 1,2,4-TCB was the greatest on CEL biochars ranging from 58.31 to 601.20 mg g(-1), and can be best explained by their huge surface area and micropore volume. Hydrophobic partitioning-sorption into 'soft' amorphous alkyl carbon may account for the second greatest Qfm (45.09-56.57 mg g(-1)) on HEM biochars under low pyrolytic temperatures (250-350 °C) with the lowest surface area. LIG biochars with more compact and smooth aromatic structure surface may undergo a surface monolayer specific adsorption. The Qfm (87.86-196.53 mg g(-1)) on C-H-L biochars were largely dependent on CEL and HEM components for their outstanding sorption capacity and higher content in biomass. Therefore, the results highlighted the importance of CEL and HEM components for 1,2,4-TCB sorption to biochar., (Copyright © 2016. Published by Elsevier Ltd.)

Besides pyrolysis the technology of hydrothermal carbonization (HTC) is tested to produce hydrochars for soil improvement. The chemical and physical properties of the hydrochars mainly depend on the feedstock and the process parameters reaction time and process temperature. Systematic investigations on the influences of these process parameters on soil properties of hydrochars like water holding capacity (WHC) and cation exchange capacity (CEC) are missing. In this study, a rush-rich biomass was carbonized within defined HTC process conditions under variation of reaction time and process temperature to produce hydrochars. Analysis of WHC, CEC, the elemental composition and Fourier-transform infrared spectroscopy (FT-IR) were performed to evaluate the influence of HTC process conditions on the pedological hydrochar properties. The results indicated that at increasing reaction severity (reaction time and process temperature) WHC and CEC decreased as well as the elemental O/C ratio. The decrease of WHC and CEC is based on the decrease of the hydrochar surface polarity. However, even the lowest WHC and CEC of investigated hydrochars still exceeded those of pure quartz sand by factors of 5-10. An application of hydrochars produced at severe HTC conditions could improve WHC and CEC of sandy soils. This has to be investigated in further studies., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

It is unclear how the properties of biochar control its ability to sorb metals. In this work, physicochemical properties of a variety of biochars, made from four types of feedstock at three pyrolysis temperatures (300, 450 and 600°C) were compared to their ability to sorb arsenic (As) and lead (Pb) in aqueous solutions. Experimental results showed that both feedstock types and pyrolysis temperature affected biochar's production rate, i.e., ratio of mass of biochar and biomass, thermal stability, elemental composition, non-combustible component (NCC) content, pH values, surface areas and thus their sorption ability to the two metals in aqueous solution. In general, the high temperature biochars had low O/C and H/C ratios, were more carbonized with larger surface area, and were more concentrated with alkaline cations. In addition, biochars made from woody feedstocks had larger surface area, but lower NCC contents than that made from grasses under the same conditions. Although all the tested biochars removed both As and Pb from aqueous solutions, they showed different sorption abilities because of the variations in properties. Statistical analyses suggested that feedstock type affected the sorption ability of the biochars to both As and Pb significantly (p<0.001). Pyrolysis temperature, however, showed little influence on biochar sorption of Pb in aqueous solutions. Statistical analyses also showed that electrostatic interaction played an important role in controlling the sorption of both As(V) and Pb(II) onto the biochar. Other mechanisms, such as precipitation and surface complexation, could also control the sorption of Pb(II) onto the biochars., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

With the increasing production of municipal sewage sludge (MSS) worldwide, the development of efficient and sustainable strategies for its management is crucial. Pyrolysis of MSS offers several benefits, including volume reduction, pathogen elimination, and energy recovery through the production of biochar, syngas, and bio-oil. However, the process can be limited by the composition of the MSS, which can affect the quality of the biochar. Co-pyrolysis has emerged as a promising solution for the sustainable management of MSS, reducing the toxicity of biochar and improving its physical and chemical properties to expand its potential applications. This review discusses the status of MSS as a feedstock for biochar production. It describes the types and properties of various co-substrates grouped according to European biochar certification requirements, including those from forestry and wood processing, agriculture, food processing residues, recycling, anaerobic digestion, and other sources. In addition, the review addresses the optimization of co-pyrolysis conditions, including the type of furnace, mixing ratio of MSS and co-substrate, co-pyrolysis temperature, residence time, heating rate, type of inert gas, and flow rate. This overview shows the potential of different biomass types for the upgrading of MSS biochar and provides a basis for research into new co-substrates. This approach not only mitigates the environmental impact of MSS but also contributes to the wider goal of achieving a circular economy in MSS management. [ABSTRACT FROM AUTHOR]

The production of biochar through pyrolysis of biomass is expected to reduce dependence on traditional energy sources and mitigate global warming. However, current predictive models for biochar yield and composition are computationally intensive, complex, and lack accuracy for extrapolative scenarios. This study utilized machine learning to develop predictive models for biochar yield and carbon content based on pyrolysis data from lignocellulosic biomass. Assessing the importance of input features revealed their significant role in predicting biochar properties. The findings indicate that eXtreme Gradient Boosting (XGBoost) algorithms can accurately forecast biochar yield and carbon content based on biomass characteristics and pyrolysis conditions. This research contributes new insights into understanding biomass pyrolysis and enhancing biochar production efficiency. [ABSTRACT FROM AUTHOR]

Banana peels waste can be utilized to produce high quality biochar that can be incorporated into the soil for sustainable production of crops. This research analyzed several properties of the biochar produced from the banana peel at different temperatures, residence times and heating rates. This study focuses on the biochar yield and the EDX analysis of the biochar produced. Response surface methodology using central composite design (CCD) was used to optimize these parameters in the batch reactor pyrolysis system. These factors were operated in different ranges for banana peels, in which pyrolysis temperature (200 to 600°C), residence time (60 to 180 min) and heating rate (5 to 15°C·min[sup -1]) were varied using 20 experiments respectively. Quality of the biochar was determined based on the biochar yield and O/C ratio. The optimum biochar chosen from the CCD model was applied to several pots of Ipomoea aquatica in different biochar dosage levels of 0, 3, 9 and 15 g (0, 1, 3 and 5 wt% of soil) respectively. Pot experiment was conducted with completely randomized design (CRD) of one factor with five replications to correlate the average plant heights with the biochar dosage levels. Results showed that biochar dosage of 1% yields the highest average final Ipomoea aquatica plant height of 37.04 cm. [ABSTRACT FROM AUTHOR]

Biochar, a carbon-rich material produced from biomass waste through thermal conversion, holds great environmental promise. This article offers a comprehensive overview of the various feedstocks used in biochar production, the different types of thermal degradation processes, biochar characterization, properties, modifications to engineered materials, and their applications in the environment. The quality of biochar, including surface area, pore size and volume, and functional group formation, is significantly influenced by the specific conditions under which thermal conversion takes place. Each of the diverse processes employed to produce biochar yields a distinct set of properties in the final product. In recent years, biochar has gained widespread recognition and utilization in diverse fields such as wastewater treatment, carbon sequestration, reduction of greenhouse gas emissions, biogas production, catalysis in biofuel industries, construction, and soil enhancement. In summary, biochar is a promising environmental mitigation tool to achieve a sustainable environment. In addition to its benefits, the application of biochar presents several challenges, including the selection of feedstocks, methods of biochar production, modifications to biochar, the properties of biochar, and the specific applications of biochar. The current review summarizes factors that could lead to significant advancements in future applications. Highlights: The feedstocks and production of biochar were discussed. Activation of biochar and properties of biochar were narrated and summarized. Application of biochar for sustainable environment was discussed. [ABSTRACT FROM AUTHOR]

In this industrialized world, in which the daily consumption of fossil fuels occurs, companies seek to prioritize energy generation through renewable energy sources with minimal environmental impact to improve their energy efficiency. The research objective was to calculate CO2 emissions for the pyrolysis process (conventional low-temperature pyrolysis) in two types of reactors, electric and traditional, where solar panels power the electric reactor. In addition, the amount of polluting gases and the energy consumption necessary to convert biomass into biochar were compared. Residual lignocellulosic biomass (RLB) from various species present in the southern region of Ecuador (eucalyptus, capuli, and acacia) was used, with three replicates per reactor. The electrical reactor (ER) consumed 82.60% less energy than the primary forest biomass fuel "traditional reactor (TR)" and distributed heat better in each pyrolytic process. The TR generated more pollution than the ER; it generated 40.48% more CO, 50% more NO2, 66.67% more SO2, and 79.63% more CH4. Undoubtedly, the pyrolysis process in an ER reduces environmental pollution and creates new bioproducts that could replace fossil fuels. This study provides relevant information on the residual biomass pyrolysis of plant species. These species are traditionally grown in the southern Ecuadorian region. In addition, an analysis of polluting gases for the TR and ER is presented. [ABSTRACT FROM AUTHOR]

Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO2eq. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in drinking water is a growing concern due to its severe health effects on humans. Among the many metals, lead (Pb), which is a toxic and harmful element, has the most widespread global distribution. Pb pollution is a major problem of water pollution in developing countries and nations. The most common sources of lead in drinking water are lead pipes, faucets, and plumbing fixtures. Adsorption is the most efficient method for metal removal, and activated carbon has been used widely in many applications as an effective adsorbent, but its high production costs have created the necessity for a low-cost alternative adsorbent. Biochar can be a cost-effective substitute for activated carbon in lead adsorption because of its porous structure, irregular surface, high surface-to-volume ratio, and presence of oxygenated functional groups. Extensive research has explored the remarkable potential of biochar in adsorbing Pb from water and wastewater through batch and column studies. Despite its efficacy in Pb removal, several challenges hinder the real application of biochar as an adsorbent. These challenges include variability in the adsorption capacity due to the diverse range of biomass feedstocks, production processes, pH dependence, potential desorption, or a leaching of Pb from the biochar back into the solution; the regeneration and reutilization of spent biochar; and a lack of studies on scalability issues for its application as an adsorbent. This manuscript aims to review the last ten years of research, highlighting the opportunities and engineering challenges associated with using biochar for Pb removal from water. Biochar production and activation methods, kinetics, adsorption isotherms, mechanisms, regeneration, and adsorption capacities with process conditions are discussed. The objective is to provide a comprehensive resource that can guide future researchers and practitioners in addressing engineering challenges. [ABSTRACT FROM AUTHOR]

Biochar enriched with metals has an increased potential for sorption of organic and inorganic pollutants. The aim of the research was to identify the possibility of using biochar composites produced on the basis of waste plant biomass and waste FFH (ferryferrohydrosol) containing iron atoms, after CO2 capture. The composites were produced in a one-stage or two-stage pyrolysis process. Their selected properties were determined as follows: pH, ash content, C, H, N, O, specific surface area, microstructure and the presence of surface functional groups. The produced biochar and composites had different properties resulting from the production method and the additive used. The results of experiments on the removal of methylene blue (MB) from solutions allowed us to rank the adsorbents used according to the maximum dye removal value achieved as follows: BC1 (94.99%), B (84.61%), BC2 (84.09%), BC3 (83.23%) and BC4 (83.23%). In terms of maximum amoxicillin removal efficiency, the ranking is as follows: BC1 (55.49%), BC3 (23.51%), BC2 (18.13%), B (13.50%) and BC4 (5.98%). The maximum efficiency of diclofenac removal was demonstrated by adsorbents BC1 (98.71), BC3 (87.08%), BC4 (74.20%), B (36.70%) and BC2 (30.40%). The most effective removal of metals Zn, Pb and Cd from the solution was demonstrated by BC1 and BC3 composites. The final concentration of the tested metals after sorption using these composites was less than 1% of the initial concentration. The highest increase in biomass on prepared substrates was recorded for the BC5 composite. It was higher by 90% and 54% (for doses of 30 g and 15 g, respectively) in relation to the biomass growth in the soil without additives. The BC1 composite can be used in pollutant sorption processes. However, BC5 has great potential as a soil additive in crop yield and plant growth. [ABSTRACT FROM AUTHOR]

Hierarchical-porous-structured materials have been widely used in the field of electromagnetic wave (EMW) absorption, playing a critical role in minimizing EMW interference and pollution. High-quality EMW absorbers, characterized by a lower thickness, lighter weight, wider absorption band, and stronger absorption capacity, have been instrumental in reducing damage and preventing malfunctions in the automotive and aviation industries. The utilization of discarded nut shells through recycling can not only alleviate environmental problems but relieve resource constraints. Herein, a facile method for the preparation of hierarchical porous biomass carbon derived from abandoned Xanthoceras Sorbifolium Bunge Shell (XSS) biomass was developed for high-performance EMW absorption. The porous structures of XSS biochar were studied by using different levels of the K2CO3 activator and simple carbonization. The effect of K2CO3 on the EMW parameters, including the complex permittivity, complex permeability, polarization relaxation, and impedance matching, was analyzed. The best EMW absorption performance of the XSS biochar was observed at a mass ratio of activator-to-biomass of 2:1. A minimum reflection loss (RLmin) of −38.9 dB was achieved at 9.12 GHz, and a maximum effective absorption bandwidth (EABmax) of up to 3.28 GHz (14.72~18.0 GHz) could be obtained at a 1.8 mm thickness. These results demonstrated that hierarchical porous XSS carbon was prepared successfully. Simultaneously, the prepared XSS biochar was confirmed as a potential and powerfully attractive EMW-absorbing material. The proposal also provided a simple strategy for the development of a green, low-cost, and sustainable biochar as a lightweight high-performance absorbing material. [ABSTRACT FROM AUTHOR]

The metallurgical sector is one of the most emission- and energy-intensive industries. The possibility of using fossil carbon substitutes has been investigated to reduce the environmental impact of the steelmaking sector. Among others, biochar emerged as a promising fossil coal/coke substitute. We conducted a literature review on biochar use in the metallurgical sector and its potential environmental benefits. The possibility for biochar as a coal/coke substitute is influenced by the source of biochar production and the process within which it can be used. In general, it has been observed that substitution of biochar ranging from a minimum of 5% to a maximum of 50% (mostly around 20–25%) is possible without affecting, or in some cases improving, the process, in coke making, iron sintering, blast furnaces and electric furnaces application. In some studies, the potential CO2 reduction due to biochar use was estimated, ranging from 5% to about 50%. Despite there still being an area of further investigation, biochar appeared as a promising resource with a variety of uses in the metallurgical sector, contributing to the lowering of the environmental impact of the sector. [ABSTRACT FROM AUTHOR]

The field of material sciences has evolved vastly in the last two decades, largely due to the discovery of carbon nanomaterials such as graphene and its derivatives. Although they offer positive characteristics, the cost of production and material processing of these carbon nanomaterials has limited their application. However, scientists have started searching for cheaper and more environmentally friendly alternatives. Biochar, a carbonaceous material derived from biowaste, is the most viable alternative, as it offers characteristics on par with traditional carbon nanomaterials. This review will discuss the production of biochar from biomass, methods of production, the effects various conditions have on the production of biochar, biomass selection, current biochar applications, and the potential biochar has to produce hydrogen as an energy carrier. [ABSTRACT FROM AUTHOR]

Biochar, an organic, porous, and carbon-rich material originating from biomass via pyrolysis, showcases compelling attributes and intrinsic performances. Its appeal as a reinforcement material for biocomposites, as well as its auspicious electrical properties, has gained more attention, and makes biochar a versatile candidate for applications ranging from energy storage to catalytic devices. This scientific review undertakes a comprehensive exploration of biochar, spanning production methodologies, physicochemical intricacies, and critical process parameters. The focus of this paper extends to optimization strategies for biochar properties tailored to specific applications, with a dedicated inquiry into diverse production methods and activation strategies. This review's second phase delves into a meticulous analysis of key properties within biochar-based composites, emphasizing limitations and unique performance characteristics crucial for diverse applications. By synthesizing a substantial body of research, this review aims to catalyze future investigations by pinpointing areas that demand attention in upcoming experiments, ultimately emphasizing the profound potential of biochar-based materials across technical and scientific domains. [ABSTRACT FROM AUTHOR]

Current concern over the decrease in the use of fossil fuels has led to the study of various options as an alternative to replace them in the transportation and industrial sectors. Different materials, such as agricultural products, lignocellulosic residues, solid wastewater products, and algae, can be used in the production of biochar and, through a sulfonation process, it can be converted it into a heterogeneous acid catalyst. The purpose of this study was employed coconut mesocarp as lignocellulosic biomass feedstock, obtaining sulfonated biochar (BACS), and evaluates its use in biodiesel production, comparing it with a KOH catalyst. The methodology included the pyrolysis of coconut mesocarp and the activation with H2SO4 for BACS production. BACS was characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, BET surface area analysis and elemental analysis. The biodiesel obtained by BACS and biodiesel obtained by KOH were compared using international biodiesel standards. An activated sulfonated biochar with a sulfonation percentage of 15.23% was successfully obtained, providing a higher FAME conversion percentage than the KOH catalyst. During the characterization of the biodiesel obtained with both catalysts, it was found that KOH meets the specified standards, while the BACS catalyst requires variations in reaction temperature or blending with diesel to comply with the biodiesel characteristics. Additionally, it was observed that the coconut mesocarp-based catalyst showed a 2.78% reduction after the first working cycle, allowing for its reuse without the need for a new sulfonation process.

Abstract Biochar, a carbon-rich material produced from biomass waste through thermal conversion, holds great environmental promise. This article offers a comprehensive overview of the various feedstocks used in biochar production, the different types of thermal degradation processes, biochar characterization, properties, modifications to engineered materials, and their applications in the environment. The quality of biochar, including surface area, pore size and volume, and functional group formation, is significantly influenced by the specific conditions under which thermal conversion takes place. Each of the diverse processes employed to produce biochar yields a distinct set of properties in the final product. In recent years, biochar has gained widespread recognition and utilization in diverse fields such as wastewater treatment, carbon sequestration, reduction of greenhouse gas emissions, biogas production, catalysis in biofuel industries, construction, and soil enhancement. In summary, biochar is a promising environmental mitigation tool to achieve a sustainable environment. In addition to its benefits, the application of biochar presents several challenges, including the selection of feedstocks, methods of biochar production, modifications to biochar, the properties of biochar, and the specific applications of biochar. The current review summarizes factors that could lead to significant advancements in future applications. Graphical Abstract

Heavy metal contamination in drinking water is a growing concern due to its severe health effects on humans. Among the many metals, lead (Pb), which is a toxic and harmful element, has the most widespread global distribution. Pb pollution is a major problem of water pollution in developing countries and nations. The most common sources of lead in drinking water are lead pipes, faucets, and plumbing fixtures. Adsorption is the most efficient method for metal removal, and activated carbon has been used widely in many applications as an effective adsorbent, but its high production costs have created the necessity for a low-cost alternative adsorbent. Biochar can be a cost-effective substitute for activated carbon in lead adsorption because of its porous structure, irregular surface, high surface-to-volume ratio, and presence of oxygenated functional groups. Extensive research has explored the remarkable potential of biochar in adsorbing Pb from water and wastewater through batch and column studies. Despite its efficacy in Pb removal, several challenges hinder the real application of biochar as an adsorbent. These challenges include variability in the adsorption capacity due to the diverse range of biomass feedstocks, production processes, pH dependence, potential desorption, or a leaching of Pb from the biochar back into the solution; the regeneration and reutilization of spent biochar; and a lack of studies on scalability issues for its application as an adsorbent. This manuscript aims to review the last ten years of research, highlighting the opportunities and engineering challenges associated with using biochar for Pb removal from water. Biochar production and activation methods, kinetics, adsorption isotherms, mechanisms, regeneration, and adsorption capacities with process conditions are discussed. The objective is to provide a comprehensive resource that can guide future researchers and practitioners in addressing engineering challenges.

Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO2eq.

Over the years, promising results have been demonstrated using various biomass-based adsorbents for the treatment of wastewater. However, the circular economy prospect of these adsorbents has been grossly neglected. This mini-review provides an inclusive overview of the applications of biomass-derived biochar in wastewater treatment within the framework of a circular economy. The application of biomass-based adsorbents for the treatment of various contaminants such as organic pollutants, heavy metals, nutrients, and leachates were highlighted. It further discusses the adsorption capacity of different biochar types and the performance evaluation of biochar-based treatment systems. In addition, the circular economy approach of biochar in the construction industry, the refinery sector, and sustainable agricultural practices were discussed. What’s more? The application of machine learning for the study of biochar was briefly discussed. Furthermore, the review examines the environmental and economic considerations associated with the utilization of biomass-derived biochar toward achieving eco-friendliness and environmental sustainability. Finally, research gaps were identified for future research development.

Anaerobic digestate is a nutrient rich slurry by-product derived from biogas production, often used as a fertiliser due to its high nitrogen content. However, nitrogen losses from its application can lead to environmental pollution. In a laboratory experiment, the addition of high organic carbon materials to digestateamended soil as a potential means to stimulate microbial immobilisation of digestate supplied nitrogen was investigated. Soil was incubated in pots for 5 months with digestate (equivalent to 250 kgN ha-1). The impact of adding carbon into the digestate (equivalent to 540 kgC ha-1) as either glycerol, straw, woodchip, or biochar on soil microbial and chemical parameters was quantified. Glycerol amended soils had significantly higher microbial biomass compared to digestate alone during the first month and at 30 days after application had a 4x higher on average microbial N. The digestate + straw treatment resulted in a 2.5x significantly greater nitrogen immobilisation compared to digestate alone after 3 months of incubation. The digestate + woodchip had a 2× higher mean microbial N after 5 months, whilst the biochar amendment did not stimulate significant nitrogen immobilisation at any time. These results suggest that mixing a labile to moderately labile organic carbon amendment, such as straw, with digestate has the greatest potential to reduce nitrogen losses following digestate application through microbial immobilisation. [ABSTRACT FROM AUTHOR]

Efficient energy storage systems are crucial for the optimal utilization of renewable energy. Sodium‐ion batteries (SIBs) are considered potential substitutes for next‐generation low‐cost energy storage systems due to the low cost and abundance of sodium resources. However, the industrialization of SIBs faces a great challenge in terms of the anode. Hard carbon could be a promising anode material due to its high capacity and low cost which originates from biomass. This study used pre‐treatment and template carbonization methods to extract a hard carbon material from a large amount of discarded biomass in bamboo powder waste. This material has a good initial Coulombic efficiency of 78.6 % and good cycling stability when applied to sodium ion batteries.Typically, the optimal hard carbon material is used as the anode to prepare sodium ion battery prototypes to demonstrate their potential applications. The anode exhibited excellent sodium storage performance with a reversible capacity of 303 mAh ⋅ g−1 at 1 C rate and good cycling performance, retaining 92.0 % of its capacity after 100 cycles. These results demonstrate that BPPHC is a promising candidate for anode material in sodium‐ion batteries. This work suggests that bamboo powder could be a low‐cost anode material for SIBs. [ABSTRACT FROM AUTHOR]

Environmental restoration and sustainable energy solutions require effective management and utilization of agricultural crop residues to reduce greenhouse gas emissions. Biowastes are a valuable resource that can be converted into biofuels and their byproducts, solving the energy crisis and reducing environmental impact. In this study, teff husk, primarily generated in Ethiopia during the production of teff within the agro-industrial sector, is used as a feedstock for slow pyrolysis. Ethiopia generates an estimated annual production of over 1.75 million tons of teff husk, a significant portion of which is incinerated, resulting in significant pollution of the environment. This study focuses on assessing teff husk as a potential material for slow pyrolysis, a crucial stage in biochar production, to tap into its biochar-producing potential. To identify the composition of biomass, the teff husk underwent an initial analysis using thermogravimetry. The significant presence of fixed carbon indicates that teff husk is a viable candidate for pyrolytic conversion into biochar particles. The process of slow pyrolysis took place at three temperatures—specifically, 400, 450, and 500 °C. The maximum biochar yield was achieved by optimizing slow pyrolysis parameters including reaction time, temperature, and heating rate. The optimized reaction time, temperature, and heating rate of 120 min, 400 °C, and 4.2 °C/min, respectively, resulted in the highest biochar yield of 43.4 wt.%. Furthermore, biochar's physicochemical, SEM-EDX, FTIR, and TGA characterization were performed. As the temperature of biochar increases, its carbon content and thermal stability increases as well. Unlike fuel recovery, the results suggest that teff-husk can be used as a feedstock for biochar production. [ABSTRACT FROM AUTHOR]

Biochar has demonstrated potential for stabilising high yields and sequestering carbon in dryland farmland, but it is unclear whether biochar affects the carbon sequestration capacity and carbon balance of annual farmland ecosystems. For this purpose, we conducted a plot control trial in salinised farmland in 2019-2021, where we set three treatments, control, and two biochar rates, 0 (CK), 15 (B15), and 30 t/ha (B30). The results showed that biochar application decreased soil organic carbon stocks in the early part of the experiment (first freeze and freeze period); these increased in the later part, and overall, the biochar treatments increased soil organic carbon storage by 3-6% compared with the control. Compared with the control (CK), biochar inhibited the total soil respiration rate and microbial respiration rate significantly (P < 0.05) during the crop growing period compared with the freeze-thaw period. After two years of freeze-thaw cycling, biochar application increased sunflower plant carbon sequestration and net primary productivity and suppressed total soil microbial respiration, thereby increasing net ecosystem productivity. Therefore, the application of biochar is conducive to carbon sequestration in farmland ecosystems and presents a carbon sink effect, thus being a good choice for improving the soil carbon pool and reducing emissions in the northern dry zone. [ABSTRACT FROM AUTHOR]

The high demand for carbon-based products within pyrometallurgy is placing the industry in an increasingly challenging position to meet stringent requirements. To transition away from fossil carbon carriers, biochar emerges as a sustainable and CO2-neutral alternative, presenting a viable solution without necessitating fundamental adjustments to plant technology, unlike hydrogen as an alternative reducing agent. Prior investigations have underscored the potential of woody biomass pyrolysis products for CO2-neutral metallurgy. Nonetheless, it is imperative to recognize that biochar must meet distinct requirements across various metallurgical processes. This paper conducts a comparative analysis between biochar and petroleum coke using thermogravimetric analyses, surface measurements, reactivity assessments, and scanning electron microscopy. Furthermore, the performance in a furnace for simulating the Waelz process, specifically regarding ZnO reduction, is scrutinized. The results illustrate the optical differences between petroleum coke and biochar and the significantly higher reactivity and specific surface area of biochar. When used in solid–gas reactors, it is observed that due to its high reactivity, biochar reacts more vigorously and carbon is completely consumed. However, during the reduction of ZnO, only minor differences were monitored, making biochar comparable to petroleum coke. Therefore, under certain constraints, biochar can be considered a potential substitute for metallurgical solid–gas reactions. [ABSTRACT FROM AUTHOR]

The pretreatment for torrefaction impacts the performance of biomass fuels and operational costs. Given their diversity, it is crucial to determine the optimal torrefaction conditions for different types of biomass. In this study, three typical solid biofuels, corn stover (CS), agaric fungus bran (AFB), and spent coffee grounds (SCGs), were prepared using fluidized bed torrefaction. The thermal stability of different fuels was extensively discussed and a novel comprehensive fuel index, "displacement level", was analyzed. The functional groups, pore structures, and microstructural differences between the three raw materials and the optimally torrefied biochar were thoroughly characterized. Finally, the biomass fuel consumption for household heating and water supply was calculated. The results showed that the optimal torrefaction temperatures for CS, AFB, and SCGs were 240, 280, and 280 °C, respectively, with comprehensive quality rankings of the optimal torrefied biochar of AFB (260) > SCG (252) > CS (248). Additionally, the economic costs of the optimally torrefied biochar were reduced by 7.03–19.32%. The results indicated that the displacement level is an index universally applicable to the preparation of solid fuels through biomass torrefaction. AFB is the most suitable solid fuel to be upgraded through torrefaction and has the potential to replace coal. [ABSTRACT FROM AUTHOR]

The current energy policy targets reducing energy dependence and minimizing pollutant emissions. Therefore, with the growing interest in using biomass as an alternative energy source, conducting scientific studies on its behavior and optimizing the respective conversion systems has become imperative. The present study focuses on investigating the combustion of biochar pellets in a laboratory-scale traveling grate furnace at three different bed temperatures: 700, 750, and 800 °C. The biochars were obtained via the carbonization process of Pinus pinaster, Acacia dealbata, and Cytisus scoparius pellets. The biochar combustion was studied using a moving-bed carbon particle burning model, supported by kinetic information which was obtained via the combustion of the same biochars in a bubbling fluidized bed. The diffusive parameter which was representative of this traveling grate combustion technology was determined, particularly the bed bypass factor. The combustion tests were carried out with the incomplete combustion of the char pellets. In general, the increase in biochar size led to a decrease in the bypass factor. However, the furnace temperature did not influence this parameter. [ABSTRACT FROM AUTHOR]

Biomass energy for heating is going to be part of the spectrum of renewable energy sources. However, biomass combustion produces emissions of various pollutants with negative effects at both local and global scales. To reduce some of the locally important pollutant load, thermally treated biomass fuels may offer a partial solution. In this study, two biomass feedstocks, i.e., spruce chips and rapeseed straw, were thermally treated at 300 °C to produce biochars. Subsequently, both original materials and biochars were burned in a 25 kW retort combustion device. In both cases, the biochar showed lower emissions of carbon monoxide and nitrogen oxides, usually almost across the whole range of tested combustion conditions. In total, for the emission production per unit of net calorific value, the spruce biochar showed reductions in CO and NOx productions of 10.8% and 14.5%, respectively. More importantly, in rapeseed straw biochar, the difference was more pronounced. The total production was reduced by 28% and 42%, again in CO and NOx emissions, respectively. [ABSTRACT FROM AUTHOR]

Objective: In this study, we aimed to investigate the effects of facile combinations of biochar and N, P, and K fertilisers on the growth and physiological characteristics of Lithocarpus litseifolius seedlings, and to optimise the biochar/NPK ratio of Lithocarpus litseifolius. Method: A four-factor three-level orthogonal method was used to conduct a field experiment using 2-year-old Lithocarpus litseifolius. Nine fertiliser treatments and one control treatment (CK, i.e., no fertiliser) were established in a completely randomised block group with six replications of ten treatments. The plants were planted in October 2020 and harvested in November 2021, and fertiliser was applied once in April 2021 and once in July 2021. Results: Rational application could effectively promote the growth of Lithocarpus litseifolius, and T4(C2N1P2K3) produced the highest increase in plant height growth (17.03 cm), diameter growth (5.47 mm), soluble sugar (94.60 mg/g), soluble protein (4.59 mg/g), and phlorizin (old leaf: 16.00%; tender leaf: 15.13%); T8(C3N2P1K3) resulted in the highest chlorophyll a content (1.46 mg/g), chlorophyll b content (0.62 mg/g), and total chlorophyll content (2.08 mg/g), and T1(C1N1P1K1) resulted in the highest contents of starch (11.60 mg/g) and trilobatin (old leaf: 0.29%; tender leaf: 2.28%). The indicators corresponding to the above three treatments were significantly higher than those under the other treatments (p < 0.05). The results as analysed by the affiliation function method show that the highest mean value of the affiliation function was 0.645 after T4(C2N1P2K3) treatment. Conclusions: The combination of biochar and nitrogen, phosphorus, and potassium fertilisers can effectively increase the biomass and active components of Lithocarpus litseifolius while reducing the amount of chemical fertiliser applied. A comprehensive analysis of the results showed that the T4 treatment (biochar: 20 g/plant; urea: 10 g/plant; superphosphate: 9 g/plant; potassium chloride: 12 g/plant) resulted in the highest comprehensive score, with the highest increase in plant height growth, ground diameter growth, root–crown ratio, soluble sugar, soluble protein, and phlorizin, as well as other indicators. [ABSTRACT FROM AUTHOR]

Because of the current energy crisis, researchers are looking into new potential substrates for production of biofuels and for possible ways to enhance their parameters. In line with such efforts, the current study focuses on the feasibility of processing waste from the production of cultivated tobacco. The aim of this study was to assess the potential of tobacco waste as a raw material for the production of solid biofuels, such as biochar produced through pyrolysis, and to determine its basic physicochemical properties, compared to other materials used for the production of green fuels. The analyses showed calorific values of 16.16 MJ kg−1 for the raw biomass and those in the range of 24.16–27.32 MJ kg−1 for the products of pyrolysis conducted at temperatures of 400–500 °C and with a heating time in the range of 5 to 15 min. To address the safety-related issues, the study also measured the explosion index (Kst max), which, in the raw biomass, amounted to 72.62 bar s−1 and in the biochar was in the range between 82.42 and 88.11 bar s−1. The registered maximum explosion pressure was 7.37 bar in the case of raw biomass, whereas in the biochars, the value ranged from 8.09 to 8.94 bar. The findings show that tobacco waste has parameters comparable to those identified in the case of other solid biofuels, whereas the process of pyrolysis enhances the energy-related parameters without increasing the explosion class of the product. [ABSTRACT FROM AUTHOR]

Maintaining healthy soils and restoring marginal lands are necessary to ensure efficient food production and food security. Biochar, a porous carbon-rich material generated from the pyrolysis of organic feedstock, is receiving attention as a soil amendment that can potentially restore soil health and enhance crop yields. However, the physical and chemical properties of biochar are influenced by pyrolysis parameters and organic feedstock sources. These determine its interaction with the soil, influencing its impact on soil health and plant productivity. While most studies report the evaluation of one biochar and a single plant cultivar, the role of genetic background in responding to biochar as a soil amendment remains unexplored. The impact of six biochars on agronomic performance and fruit quality of three tomato (Solanum lycopersicum) cultivars was evaluated to test the hypotheses that (1) biochars derived from different feedstock sources would produce unique phenotypes in a single cultivar of tomato, and (2) single feedstock-derived biochar would produce different phenotypes in each of the three tomato cultivars. The data supported both hypotheses. This study demonstrated that plant genetic background and biomass source are important variables that must be considered for using biochar as a soil amendment. [ABSTRACT FROM AUTHOR]

With the rapid growth in the global population and the accelerating pace of urbanization, researching and developing novel strategies for biomass utilization is significant due to its potential for use in renewable energy, climate change mitigation, waste management, and sustainable agriculture. In this environmental context, this review discusses the recent advances in biomass conversion technologies for biochar production, including the first carbonization process and the subsequent activation methods of the biochar derived from lignocellulosic biomass (LBC). Parallel to this, this review deals with other essential parameters in biochar production, such as feedstock types, reaction environments, and operating conditions in the pyrolysis process, to determine the production and composition of LBC. Moreover, the wide-ranging applications of LBC in areas such as adsorption, catalysts, and energy storage are discussed, offering sustainable and environmentally friendly alternatives while reducing reliance on traditional energy sources and mineral resources, thereby providing practical solutions to environmental and energy challenges. Overall, this review not only provides a comprehensive comparative analysis of different LBC preparation methods, but also facilitates a deeper understanding of the advantages and limitations of these methodologies when it comes to developing high-value materials for sustainable applications. [ABSTRACT FROM AUTHOR]

This study aimed to assess the value of Pachira aquatica Aubl. fruit peels by exploring their applicability in the biosorption process for the removal of Ni(II) and Cd(II) metal ions. The Pachira aquatica Aubl. fruit peel biochar (PAB) was extensively characterized through various techniques, including proximate analysis, helium pycnometer, XRD, SEM, point of zero charge determination, zeta potential measurement, and Boehm titration. Subsequently, kinetic, isotherm, and thermodynamic batch biosorption studies were conducted, followed by column biosorption tests. The characteristics of PAB, including low moisture content, a neutral point of zero charge, porosity, an irregular and heterogeneous structure, a negatively charged surface, and the presence of functional groups, indicate its remarkable capacity for efficiently binding with heavy metals. Biosorption equilibrium time was achieved at 300 min for both ions, fitting well with a pseudo second-order kinetic model and Langmuir isotherm model. These data suggest that the biosorption process occurred chemically in monolayer. The column C presented an exhaust volume of 1200 mL for Ni(II) and 1080 for Cd(II) and removal of 98% and 99% of removal for Ni(II) and Cd(II), respectively. In summary, PAB demonstrates substantial potential as a biosorbent for effectively removing heavy metals, making a valuable contribution to the valorization of this co-product and the mitigation of environmental pollution. [ABSTRACT FROM AUTHOR]

The subject of our research was to assess the suitability of maize grown in lead-contaminated soil for energy purposes. Lead is toxic to the natural environment. Therefore, the recultivation of soil polluted with this element is very important in stabilizing the natural environment. In the present research, maize was used as a remediating plant, and its effects were enhanced by soil fertilization with biocompost and biochar. The aim of the research was to determine the influence of Pb2+ on maize biomass, its combustion heat and heating value, and the biochemical and physicochemical properties of the soil. It was accomplished in a pot experiment by testing the effects of 800 mg Pb2+ kg−1 d.m. soil and biocompost and biochar applied of 20 g kg−1 d.m. soil. Lead was found to drastically deteriorate soil quality, which reduced the biomass of maize. Lead negatively affected the activity of the soil enzymes tested and modified the physicochemical properties of the soil. Fertilization with biocompost and biochar mitigated lead-induced interference with soil enzymatic activity. The applied biocomponents also had positive effects on the chemical and physicochemical properties of the soil. Maize cultivated on lead-polluted soil did not lose its energetic properties. The heating value of maize was stable, which shows its potential in the recultivation of lead-contaminated soils. [ABSTRACT FROM AUTHOR]

Biochar's impact on plant growth is complex, varying with type and application rate. This study explored how four biochars (rice husk, cocoa shell, peanut shell, carob) affect rice (Oryza sativa L.) at five rates (0-5%). Biochar significantly enhanced rice growth, but the optimal type and rate varied. Total dry mass increased by an average of 20% in biochar-treated groups compared to controls, with rice husk and cocoa shell biochar at 5% application rate achieving the highest yields. The effects on plant components differed. While leaf mass fraction responded favorably to all biochar types, stem and root mass fractions remained largely unchanged. Additionally, root strength, as measured by root dry matter content, increased with all biochars, particularly rice husk biochar which boosted it by 8%. All biochar types also enhanced leaf mass per area, a key indicator of photosynthetic efficiency. These findings highlight the importance of tailoring biochar application strategies to specific crops and soil conditions. Optimizing biochar application based on its influence on root strength, leaf mass allocation, and growth across different crop species and soil conditions can unlock its full potential for sustainable development. [ABSTRACT FROM AUTHOR]

Four deciduous woody feedstocks (Casuarina equisetifolia L., Eucalyptus globulus, Wrightia tinctoria, and Neolamarika cadamba) were subjected to the Hydrothermal Carbonization (HTC) process inside a 50 mL stainless steel hydrothermal reactor at varying temperatures (180°C, 215°C, and 250°C), while keeping water-to-feedstock ratio (6:1 v/w%) and residence time (1.5 h) constant. The mass yield and energy yield of the resulting biomass were calculated as parameters for energy intensification. Characterization of the biomass, biochar, and bio-oil was conducted using elemental analysis, SEM, and GC-MS. Interestingly, the mass yield of biochar decreased with increasing temperature, but it significantly improved the energy densification ratio, with a minimum of 1.06 observed for Neolamarika cadamba biomass at 180°C and a maximum of 1.23 observed for Eucalyptus globulus biomass at 250°C. Moreover, detailed analysis of the bio-oil obtained at 250°C using GC-MS revealed the presence of a diverse range of fine chemicals, including benzyl, carboxylic acid, ester, methyl, phenol, pyrrole, nitro, and aliphatic hydrocarbons. These findings suggest that the HTC process can be optimized to tailor the production of specific value-added chemicals from lignocellulosic woody biomass. [ABSTRACT FROM AUTHOR]

Using waste biomass is considered one of the ways to reduce climate change. Arboreal waste biomass from pine, eucalyptus, and particularly invasive plants (Acacias) would make it possible to transform this natural resource, but needs to be adjusted to current and innovative technologies. The production of high fixed carbon biochar with this biomass would improve not only environmental aspects, but also the use of currently not susceptible materials for other types of exploitation. The objective of this study is to develop biochar from three different waste biomass materials and compare their parameters with those of the original biomass. Thermochemical conversion processes were used in a simple double chamber reactor developed for this study. Temperatures between 400 and 500 °C during 280 min were achieved and allowed to transform the initial biomass in a biochar with a high content of fixed carbon. By comparing the original biomass with the final biochar through tests of humidity, density, calorific values, fixed carbon, and cationic and elemental analysis, an increase in the parameters was confirmed. Fixed carbon of 70%, 77%, and 71% with pine, acacia, and eucalyptus biomass have been obtained, respectively, with yields between 30% and 40%. The results are favorable, particularly with acacia invasive plants, and could help in their difficult silviculture management. [ABSTRACT FROM AUTHOR]

In recent years, research on carbon dioxide removal (CDR) has significantly increased. Numerous studies have analyzed demonstration projects, outlined scenarios, modeled pathways, or focused on CDR's national or international governance. However, regional case studies investigating the dynamics that may facilitate or impede the broader adoption of CDR methods in spatially explicit settings are critically absent. Understanding implementation contexts on the ground is vital, and comparing them across different removal methods is essential for effectively scaling up CDR. This paper aims to address this research gap by comparatively examining the development of biomass-based CDR in three regions of Germany. Taking an exploratory approach, we conducted surveys in these regions to gain insight into stakeholder perceptions of the following six CDR methods: forest management, agriculture and soil carbon, long-lasting building materials, rewetting of peatlands and paludiculture, biochar, and bioenergy with carbon capture and storage. In this article, we present the results of the stakeholder survey, which offers multiple perspectives that can shape future studies of regional implementation and yield policy-relevant guidance. Although our research primarily focuses on the regional level in Germany, it sheds light on various conflicts, uncertainties, and potentials that are likely to be relevant for the rollout of CDR in other countries. By examining these aspects, we contribute to the broader discourse on CDR and its potential implementation. [ABSTRACT FROM AUTHOR]

The pyrolysis process is a thermochemical conversion reaction that encompasses an intricate array of simultaneous and competitive reactions occurring in oxygen-depleted conditions. The final products of biomass pyrolysis are bio-oil, biochar, and some gases, with their proportions determined by the pyrolysis reaction conditions and technological pathways. Typically, low-temperature slow pyrolysis (reaction temperature below 500 °C) primarily yields biochar, while high-temperature fast pyrolysis (reaction temperature 700–1100 °C) mainly produces combustible gases. In the case of medium-temperature rapid pyrolysis (reaction temperature around 500–650 °C), conducted at very high heating rates and short vapor residence times (usually less than 1 s), the maximum liquid yield can reach up to 85 wt% (on a wet basis) or achieve 70 wt% (on a dry basis), with bio-oil being the predominant product. By employing the pyrolysis technique, valuable utilization of tobacco stem waste enriched with lignin can be achieved, resulting in the production of desired pyrolysis products such as transportation fuels, bio-oil, and ethanol. The present review focuses on catalytic pyrolysis, encompassing catalytic hydropyrolysis and catalytic co-pyrolysis, and meticulously compares the impact of catalyst structure on product distribution. Initially, we provide a comprehensive overview of the recent pyrolysis mechanism of lignin and tobacco waste. Subsequently, an in-depth analysis is presented, elucidating how to effectively design the catalyst structure to facilitate the efficient conversion of lignin through pyrolysis. Lastly, we delve into other innovative pyrolysis methods, including microwave-assisted and solar-assisted pyrolysis. [ABSTRACT FROM AUTHOR]

Biomass and plastics are two of the most common municipal solid wastes globally that have continuously placed a burden on the environment. It is therefore important that they are properly recycled. Thermochemical coconversion offers a valuable opportunity to recycle biomass and plastics simultaneously into biochar, which reduces the time and cost of recycling them individually while producing a material with a wide range of applications. This study is a review of published literature that discusses the thermochemical co-processing of biomass and plastic wastes into biochar. It was observed that co-pyrolysis and co-hydrothermal carbonization are the most commonly utilized technologies for this process. The characteristics of different biomass and plastics that have been thermochemically converted into biochar were compared. The properties of the resulting biochar are affected by the feedstock composition, pre-treatment and blending ratio, the reactor's configuration, reaction temperature, and the presence of a catalyst. Most studies found that treating the feedstocks separately resulted in a lower yield of biochar than processing them together. The biochar created by this procedure has been used as a soil additive and as an adsorbent for water treatment. Future perspectives and suggestions, such as the necessity for some technical advancement, biochar's economic benefits, improved government participation, and raised social awareness, were also made. These factors have the potential to propel this field of study to great horizons. [ABSTRACT FROM AUTHOR]

Abstract This study has introduced a pioneering methodology by employing biochars as a basic carbocatalyst in the context of multicomponent reactions. Biochars were produced from different manures and organic wastes using the pyrolysis-carbonization process under limited oxygen conditions. The prepared biochars were well characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) analysis, and powder X-ray diffraction (XRD). The chemical characteristics and potentiometric titration analysis provide compelling evidence of the intriguing basicity properties exhibited by the prepared biochars. The pH values, ash content, and potentiometric titration results confirmed the exceptional basicity characteristics of cow manure biochar formed at 600 oC (CB600), establishing it as the most basic carbocatalyst in this study. Encouraged by these initial results, the activity of the biochars as basic carbocatalysts was evaluated in multicomponent synthesis of 4H-benzo[h]chromene and pyranopyrazoles and 600 °C exhibited the most pronounced catalytic performance owing to its superior total basicity. By these findings, it can be asserted that this work introduces the groundbreaking application of biochars as potent basic carbocatalysts for the multicomponent synthesis of structurally diverse heterocycles. Unveiling the vital basic role of biochars will definitely open up new opportunities in organic chemistry and provide salient features for environmentally-friendly chemistry, including easy retrieval, non-toxicity, and widespread accessibility. Graphical Abstract

The low fertility of post-brick mining soil may be improved by applying biochar to the soil because biochar is an excellent soil amendment, although its quality varies depending on the raw materials used. Therefore, soil fertility, nutrient availability, and crop yields are affected by the type and amount of biochar added to soils. This study examined the effect of types and dosages of biochar on nitrogen, phosphorus, and potassium availability of post-brick mining soil to increase maize yield. The treatment combinations of biochar dosages (0 t ha-1, 15 t ha-1, 30 t ha-1, and 45 t ha-1) and biochar types (coconut shell, wood, and rice husk biochars) were arranged in randomized block design with three replications. Each treatment plot measuring 4 m x 4.5 m was planted with maize seeds with a planting space of 80 cm x 25 cm. Urea (135 kg N ha-1), SP36 (36 kg P2O5 ha-1), and KCl (110 kg K2O ha-1) were applied as basal fertilizers. The results showed that at eight weeks after biochar application, the amount and type of biochar positively affected maize yield. The application of rice-husk biochar at 30 t ha-1 resulted in the highest maize yield. The application of each type of biochar at 45 t ha-1 yielded the highest increase in the availability of nitrogen, phosphorus, and potassium in the soil.

Water hyacinth is classified as a high-risk invasive species but is a source of biomass to obtain bio-oil and biochar by pyrolysis reaction. The Kissinger- Akahira-Sunose model (KAS), Ozawa-Flynn Wall (OFW), and Friedman model, determined the pyrolysis activation energy to be 213.19 kJ mol−1, 222.55 kJ mol−1, and 248.09 kJ mol−1, respectively. Bio-oil was obtained with a 2.2% yield, and a maximum calorific value of 21,641 kJ kg−1. The composition was 44% hydrocarbons, 27% aromatic hydrocarbons, 6% alcohols and phenols, 4% acids, and 19% aldehydes, ketones, ethers, nitriles, and others. A 48.84 wt% biochar was also obtained, gaining energy and active carbon. Bio-oil could be a candidate for the production of refined chemical products.